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  • 1980-1984  (931)
  • 1980  (931)
  • Inorganic Chemistry  (757)
  • Life Sciences  (116)
  • Nuclear reactions
  • pharmacokinetics
  • 1
    Electronic Resource
    Electronic Resource
    Melatonin administration to dogs (1980)
    Springer
    Journal of neural transmission 49 (1980), S. 281-285 
    Details
    ISSN: 1435-1463
    Keywords: Melatonin administration ; diurnal rhythm ; dog ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Melatonin concentrations in serum and urine were examined following oral administration of melatonin to dogs. Four different doses of melatonin ranging from 10 to 80 mg per kg of body weight were given. Melatonin was rapidly absorbed and reached a maximum serum level after 20–30 min, with a distribution phase of 3.5 hours and elimination half life (t1/2) of 5 hours. The fraction excreted in the urine was 0.25% of the administrated dose during the first 5 hours. These results as well as the diurnal rhythm of serum melatonin in the dog are similar to corresponding data reported in the human.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01252131
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  • 2
    Electronic Resource
    Electronic Resource
    Metabolic effects and pharmacokinetics of intravenously administered dichloroacetate in humans (1980)
    Springer
    Diabetologia 19 (1980), S. 109-113 
    Details
    ISSN: 1432-0428
    Keywords: Dichloroacetate ; pharmacokinetics ; lactate ; lactic acidosis ; alanine ; glucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dichloroacetate decreases plasma glucose, lactate, and alanine concentrations in normal and diabetic subjects, and lowers lactate concentrations and increases survival in animals with experimentally induced lactic acidosis. The relationship between these effects and plasma dichloroacetate concentrations have not been previously studied in man. Dichloroacetate (1–50 mg/kg) was infused over 30 min to 16 healthy subjects and plasma drug concentrations were followed by gas chromatography over the next 8 h. Peak plasma concentrations were linearly related to the dose (r = 0.98, p〈0.001) up to 30 mg/kg, above which 4 of 7 subjects had disproportionately high plasma drug concentrations. Nonlinear disposition was also indicated by the convex decreasing plasma elimination curves; levels declining less rapidly initially than later. At plasma concentrations below 10 μg/ml, elimination was monoexponential with a half-life of 32±11 min (mean±SD). Plasma drug clearance also decreased with doses greater than 20 mg/kg. Within 2 h of administration of the maximally effective dichloroacetate dose of 35 mg/kg, plasma lactate concentrations fell 75% below baseline and alanine fell 50% below baseline, while blood glucose was unaffected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00421855
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  • 3
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of sodium valproate in epileptic patients: Prediction of maintenance dosage by single-dose study (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 71-77 
    Details
    ISSN: 1432-1041
    Keywords: sodium valproate ; epileptic patients ; pharmacokinetics ; plasma concentration ; prediction ; maintenance dosage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Pharmacokinetic analysis of the plasma valproic acid concentration-time course, following a single oral dose (600 mg) of sodium valproate, was performed in 20 epileptic patients as an aid to the prediction of a proper chronic dosage regimen. A simple one-compartment model was found inadequate to describe the drug concentration-time course in 15 of the 20 patients studied. The average elimination (β phase) half-life of 9 h was shorter than that previously reported in healthy subjects. The latter observation and the wide variation in plasma valproic acid clearance observed between patients (0.09–0.53 ml/kg/min) may have been related to its altered disposition by concomitant anticonvulsant therapy. Sodium valproate maintenance therapy, determined by single-dose pharmacokinetic prediction of steady-state plasma valproic acid levels, did not require dosage adjustment because of unwanted effects. However, the occurrence of drug-related adverse events led to dosage reduction in 4 of 9 patients whose chronic therapy was not pharmacokinetically predicted. Moreover, the pharmacokinetic variability demonstrated for sodium valproate by patients on multiple therapy, whose chronic sodium valproate therapy was pharmacokinetically predicted, indicates the value of monitoring plasma valproic acid levels for the regulation of anticonvulsant therapy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561679
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  • 4
    Electronic Resource
    Electronic Resource
    Metabolic and haemodynamic effects and pharmacokinetics of a new selective beta1-adrenoceptor agonist, prenalterol, in man (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 81-86 
    Details
    ISSN: 1432-1041
    Keywords: prenalterol ; beta1-adrenoceptor agonist ; metabolic effects ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The metabolic and haemodynamic effects of three intravenous doses (0.5, 1.0 and 4.0 mg) of prenalterol, a selective β1-adrenoceptor agonist, were studied in 10 healthy male subjects. Plasma levels of prenalterol during the experiments were related to the haemodynamic effects. Prenalterol induced a dose-dependent increase in systolic blood pressure and heart rate. The maximal effects amounted to about 30 mm Hg and 15 beats/min, respectively, after the highest dose (4.0 mg). The diastolic blood pressure fell by a maximum of about 15 mm Hg. The effect of prenalterol on systolic blood pressure and heart rate persisted for about 3 h after the end of the last infusion, whereas that on diastolic blood pressure only lasted for 60 min. Compared with placebo, there was a moderate increase in plasma FFA and glycerol. A small rise in insulin level was also recorded, but no significant change was seen in other metabolic variables — triglycerides, glucose, lactate, pyruvate. Serum potassium tended to decrease and serum sodium was unchanged. The initial distribution of prenalterol was rapid (half-life 7 min) and the overall elimination rate corresponded to a plasma half-life of 2 h. A linear relationship was found between the plasma level of prenalterol and its effects on systolic blood pressure and heart rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562614
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  • 5
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of zimelidine (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 111-116 
    Details
    ISSN: 1432-1041
    Keywords: zimelidine ; norzimelidine ; antidepressants ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The systemic availability of a new antidepressant, zimelidine, and of its pharmacologically active metabolite, norzimelidine, was studied in six healthy male volunteers. Three single doses of zimelidine (25 mg and 100 mg orally and 25 mg i.v.) and two single doses of norzimelidine (25 mg orally and i. v.) were given to each volunteer allowing at least seven days between administrations. Plasma concentrations of zimelidine and norzimelidine were determined in serial blood samples by HPLC. Following oral zimelidine peak plasma concentrations of the metabolite were attained about 3 h after dosing. Oral administration of norzimelidine itself resulted in a plasma concentration profile for this compound that was similar to that observed after oral zimelidine. Utilising the plasma concentration data following intravenous infusion of each compound, the elimination half-lives for zimelidine and norzimelidine were calculated to be 5.1 h (range 4.3–6.0) and 15.5 h (range 10.6–22.9) respectively. The total body clearances of the 2 compounds were similar at 0.52 l · min−1 (range 0.26–0.70) for zimelidine and 0.56 l · min−1 (range 0.28–0.83) for norzimelidine. The substantially longer elimination half-life of norzimelidine was apparently the result of a larger volume of distribution (9.4 l · kg−1; range 7.8–11.4) for this metabolite, as compared to zimelidine (3.21 · kg−1; range 1.6–4.9). The calculated bioavailability of zimelidine was 26% (range 9.1–39) after the 25 mg oral dose, and 29% (range 14–46) after the 100 mg dose. The bioavailability of norzimelidine was 66% (range 36–91). However, oral administration of zimelidine resulted in as much or more norzimelidine reaching the systemic circulation, as the oral administration of norzimelidine itself. This is important as a large part of the activity of the drug may be due to the metabolite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562618
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  • 6
    Electronic Resource
    Electronic Resource
    Plasma and salivary pharmacokinetics of dapsone estimated by a thin layer chromatographic method (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 129-133 
    Details
    ISSN: 1432-1041
    Keywords: dapsone ; salivary drug elimination ; pharmacokinetics ; acetylator phenotype
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A high performance thin layer chromatographic assay for dapsone is described with a minimum level of detection of 20 ng ml−1 which is suitable for the study of dapsone pharmacokinetics in plasma and saliva. 100 mg dapsone was administered orally to seven normal adult volunteers, the mean plasma pharmacokinetic parameters were: α=0.23 h−1; β=0.0236 h−1, and t1/2β=30.2 h. Dapsone is also eliminated into the saliva and the t1/2 may be determined via its estimation in saliva. It is 73% bound to plasma protein and the saliva/plasma concentration ratio was found to be 27%. In two subjects the free plasma dapsone concentration was identical to the simultaneous salivary dapsone concentration. Therefore the salivary dapsone concentration is a measure of the free plasma fraction of dapsone. Saliva/plasma dapsone concentration ratios show no time or concentration dependence and little inter-individual variation but are unsuitable for acetylator phenotype determination because monoacetyldapsone is not eliminated in the saliva.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562621
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  • 7
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of sotalol after chronic administration to patients with renal insufficiency (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 321-326 
    Details
    ISSN: 1432-1041
    Keywords: sotalol ; hypertension ; renal impairment ; chronic administration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Ten hypertensive patients with moderate to severe impairment of renal function were treated with sotalol for 5 to 10 weeks (average 6.4 weeks). Dosage was individually titrated (range 80 to 480 mg daily). The drug was given once daily in the morning. In eight patients blood pressure was satisfactorily controlled. Higher steady-state levels were observed than have been reported after similar doses in patients with normal renal function. The apparent first-order elimination rate constant and plasma clearance were significantly correlated with glomerular filtration rate. For an anuric patient, serum half-life was calculated to be 69 h. In relation to the raised plasma levels, side effects were uncommon. Since sotalol is excreted predominantly via the kidney, therapy in patients with impaired renal function should start with a low dose and any increase in dosage should be made carefully. As the anti-hypertensive effect does not appear to be correlated with the plasma level or with tolerance, adjustment of dose should be based on clinical response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561389
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  • 8
    Electronic Resource
    Electronic Resource
    Influence of cimetidine on the pharmacokinetics of desmethyldiazepam and oxazepam (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 517-520 
    Details
    ISSN: 1432-1041
    Keywords: desmethyldiazepam ; oxazepam ; cimetidine ; hepatic elimination ; pharmacokinetics ; interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of single oral doses of desmethyldiazepam 20 mg or oxazepam 50 mg were studied in 5 healthy volunteers under controlled conditions, before and following a 24 h pretreatment with cimetidine 200 mg×5. Cimetidine significantly impaired (p=0.03) the elimination of desmethyldiazepam, as shown prolongation of its elimination half-life from 51.7±21.9 h to 72.6±39.4 h (mean ± SD), and a decrease in total plasma clearance from 12.0±2.7 ml/min to 8.6±3.3 ml/min. The disposition of oxazepam was not affected. From these results, and recently published data on diazepam and chlordiazepoxide, it is concluded that cimetidine impairs the hepatic elimination of those benzodiazepines which are metabolized by phase I reactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874666
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  • 9
    Electronic Resource
    Electronic Resource
    Clinical pharmacokinetics of alcuronium chloride in man (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 449-457 
    Details
    ISSN: 1432-1041
    Keywords: alcuronium ; single dose ; multiple dose ; plasma levels ; neuromuscular response ; pharmacokinetics ; anaesthesia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetic behaviour of alcuronium is described for nineteen patients undergoing anaesthesia for elective surgery. Eleven patients received a single bolus intravenous dose of 0.25 mg/kg, while 8 patients required additional doses of 0.125 mg/kg. A two-compartment open model was found to describe adequately both the single dose and multiple dose data for the majority of patients. No significant differences were found in the model-independent pharmacokinetic parameters between the single and multiple dose studies. Mean values for the pooled data for the half-life (t1/2β), apparent volume of distribution (Vdβ), volume of distribution at steady-state (Vdss), volume of the central compartment (Vc) and plasma clearance (Clp) were 198.75 min, 24.261, 20.891, 8.181 and 90.22 ml/min respectively. Evoked muscle twitch response was monitored in 17 of the patients to assess the degree of relaxant blockade. The bolus dose of alcuronium produced complete block in 9 patients and between 95 and 99% block in the remainder. The time of onset to maximum block ranged from 3 to 30 min with the concurrently measured plasma levels of alcuronium being 0.79 to 2.25 µg/ml. The time taken following bolus administration to 5% recovery (95% paralysis) was a mean of 42 min and the corresponding mean alcuronium plasma concentration was 0.78 µg/ml.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00570163
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  • 10
    Electronic Resource
    Electronic Resource
    Paracetamol pharmacokinetics in thyroid disease (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 269-273 
    Details
    ISSN: 1432-1041
    Keywords: paracetamol ; thyrotoxicosis ; hypothyroidism ; drug disposition ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The absorption, distribution and elimination of oral paracetamol have been studied in patients before and after treatment of thyrotoxicosis (n=7) and hypothyroidism (n=4). Absorption was faster in patients with untreated thyrotoxicosis than when subsequently euthyroid. The peak paracetamol concentration, however, was lower in thyrotoxic patients due to an apparent increase in the total body clearance and a shorter plasma half-life. Both absorption and elimination rates were reduced in hypothyroid patients, but were not significantly different from the euthyroid results. When estimated using a two compartment model the total volume of distribution and the hybrid distribution rate constants were unrelated to thyroid status, but the apparent volume of the central compartment was significantly greater in the thyrotoxic group. These changes in drug disposition may contribute to differences in drug response seen in thyroid disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00563010
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  • 11
    Electronic Resource
    Electronic Resource
    Pharmacokinetic of 2-(p-methylallylaminophenyl) propionic acid, alminoprofene, in man after single and multiple oral doses (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 419-422 
    Details
    ISSN: 1432-1041
    Keywords: alminoprofene ; antalgic ; pharmacokinetics ; single dose ; multiple doses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary 2-(p-methylallylaminophenyl) propionic acid, alminoprofene (INN), a new antalgic drug, was administered orally to men as a single (300 mg) and multiple doses (300 mg three times daily). Plasma and urine concentrations of alminoprofene were determined by gas-liquid chromatography. After the single oral dose, the peak plasma level (36.2 to 41.5 mg/l) was reached within 0.5–1.5 h. The biological half-life ranged from 2.5 to 3.2 h. During chronic administration of alminoprofene, steady-state equilibrium quilibrium was etablished within 24 h. The urinary excretion of alminoprofene as unchanged product and as glucuronide was very important.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636796
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  • 12
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and oral bioavailability of pyridostigmine in man (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 423-428 
    Details
    ISSN: 1432-1041
    Keywords: pyridostigmine ; myasthenia gravis ; pharmacokinetics ; bioavailability ; plasma levels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of pyridostigmine was evaluated after intravenous injection in two healthy male volunteers and after oral administration to five subjects. Plasma concentrations of pyridostigmine were determined after ion pair extraction from plasma and analysis by gas chromatography — mass spectrometry with chemical ionization, using d6-pyridostigmine as internal standard. Degradation of pyridostigmine in vitro was compensated for by use of the deuterated internal standard and by rapid cooling and separation of plasma after blood sampling. After intravenous administration of pyridostigmine 2.5 mg the plasma elimination half-life was 1.52 h, the volume of distribution was 1.43 l/kg and the plasma clearance 0.65 l/kg × h. The pharmacokinetic constants were very similar after oral administration of pyridostigmine 120 mg; the elimination half-life was 1.78±0.24 h, the volume of distribution 1.64±0.29 l/kg and the plasma clearance was 0.66±0.22 l/kg × h. The bioavailability was calculated to be 7.6±2.4%. When pyridostigmine was taken together with food, the time to reach the peak plasma concentration was prolonged from 1.7 to 3.2 h. Bioavailability, however, was not influenced by concomitant food intake. “Steady-state” plasma concentrations of pyridostigmine were measured in myasthenic patients on their ordinary dose schedule of cholinesterase inhibitor drugs. More than a seven-fold difference in steady-state plasma concentration was found between patients taking approximately the same daily dose of pyridostigmine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636797
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  • 13
    Electronic Resource
    Electronic Resource
    Rapid prediction of steady-state serum theophylline concentration in patients treated with intravenous aminophylline (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 473-477 
    Details
    ISSN: 1432-1041
    Keywords: aminophylline ; asthma ; serum theophylline ; pharmacokinetics ; prediction of serum level
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In 15 acutely ill asthmatics the steady-state serum theophylline concentration was predicted by the method of Chiou et al. using two serum concentration measurements obtained 1 and 5h after starting a continuous infusion of aminophylline. Two theophylline assays with different precision characteristics were compared. With a precise HPLC-assay the prediction was excellent: prediction error (predicted minus measured concentration)=−0.22±1.97 mg/l (mean ± SD); r=0.922. When the theophylline concentration was determined by a rapid enzyme immunoassay of lower precision, but convenient for clinical use, the prediction was less accurate (prediction error=0.58±3.88, r=0.852). However, it was still clearly superior to dosing recommendations based on the population average of theophylline clearance, even after taking into consideration the effect of smoking, congestive heart failure and cirrhosis (prediction error=3.62±13.36, r=0.560). As employed in this study, the method may be useful in helping the physician to choose the optimal dose in severely ill asthmatics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874658
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  • 14
    Electronic Resource
    Electronic Resource
    Lack of pharmacokinetic interaction of colestipol and fenofibrate in volunteers (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 459-463 
    Details
    ISSN: 1432-1041
    Keywords: colestipol ; fenofibrate ; fenofibric acid ; pharmacokinetics ; interaction ; volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The possibility of a pharmacokinetic interaction between two hypolipidemic drugs, colestipol, an ion exchange resin, and fenofibrate, a phenoxyacid derivative, was studied in 6 male volunteers. The investigation followed a four-step protocol during 18 days, and relied on determination of plasma and urinary levels of fenofibric acid, the active metabolite of fenofibrate. The kinetics of a single dose of fenofibrate 300 mg was established over 3 days. Thereafter, from Days 4 to 9 fenofibrate was given daily as 200 mg in the morning and 100 mg in the evening; the plasma fenofibric acid level reached about 10 µg/ml. From Days 9 to 15 the same dose of fenofibrate was administered together with colestipol 10 g in the morning and 5 g in the evening. Plasma fenofibric acid concentrations remained unchanged and the 24 h urinary excretion of fenofibric acid did not fall. On Day 15, a last single dose of fenofibrate 300 mg was given with colestipol 15 g. The pharmacokinetic pattern of fenofibric acid on Days 15 to 18 did not differ significantly from that found previously (Days 1 to 3). From these results, it is likely that there is no pharmacokinetic interaction between the two hypolipidemic drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00570164
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  • 15
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and clinical response (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 51-53 
    Details
    ISSN: 1432-1041
    Keywords: pethidine ; phenobarbital ; aminoglycoside antibiotics ; pharmacokinetics ; clinical response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561478
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  • 16
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of diuretics and methylxanthines in the neonate (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 55-63 
    Details
    ISSN: 1432-1041
    Keywords: diuretics ; furosemide ; caffeine ; theophylline ; neonate ; pharmacokinetics ; disposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The elimination of diuretics and methylxanthines is considerably slower in the neonate than in the adult. Dose guidelines, especially during long term maintenance, must be adjusted to account for this slower drug elimination. Pharmacokinetic studies and the requisite pharmacologic evaluation on diuretics such as hydrochlorothiazide, spironolactone, ethacrynic acid and others should be done. Furosemide undergoes biotransformation in the newborn producing an acid metabolite and a glucuronide conjugate. Methylxanthines are effective in the treatment of neonatal apnea. Plasma elimination of theophylline is exceedingly slow, more so with caffeine. Decreased elimination is partly explained by decreased oxidative biotransformation. Caffeine is excreted in the urine of the newborn mainly unchanged (85%) in contrast to the adult where caffeine is a minor portion of urinary excretion (2%). Theophylline is methylated to caffeine and may possibly exert additive pharmacologic effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561479
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  • 17
    Electronic Resource
    Electronic Resource
    Absorption and disposition of ampicillin in the elderly (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 195-198 
    Details
    ISSN: 1432-1041
    Keywords: ampicillin ; age ; oral dose ; i. v. dose ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Ampicillin (500 mg) was administered intravenously (i. v.) and orally to a small panel of young and elderly subjects in a cross-over fashion. Plasma concentrations of ampicillin were measured by a fluorimetric technique for 8 h following dosage. A two compartment-open model was used to characterise the plasma concentration-time data for the intravenous study, and a one compartment-open model incorporating an absorption lag time and a first-order absorption rate constant for the oral data. Plasma clearance after i. v. ampicillin was found to be significantly decreased in the elderly (P〈0.05, 0.08 1 h−1kg−1 versus 0.18 1 h−1kg−1), and half life and area under the plasma level-time curve were significantly increased (P〈0.05, 6.70 h versus 1.68 h, t1/2β; p〈0.01, 176.51 µg·h ml−1 versus 37.88 µg·h ml−1, AUC o ∞ ) as compared to the young. No sigificant differences were observed between the age groups for the volume of distribution terms and the changes in drug handling noted in the elderly were attributed to a decrease in the renal elimination of ampicillin. Following oral administration a significant increase in t1/2β, AUC o ∞ and the maximum plasma concentration (Cpmax P〈0.01, 6.59 µg ml−1 versus 3.42 µg ml−1) of ampicillin was found in the elderly subjects. These findings were similarly attributed to a decrease in drug elimination in the aged, since no apparent age differences were noted in the pharmacokinetic parameters governing both rate and extent of ampicillin absorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561590
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  • 18
    Electronic Resource
    Electronic Resource
    Effects and pharmacokinetics of isosorbide dinitrate in normal man (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 237-244 
    Details
    ISSN: 1432-1041
    Keywords: isosorbide dinitrate ; 2-isosorbide mononitrate ; 5-isosorbide mononitrate ; digital plethysmography ; hypotension ; bradycardia ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary 18 subjects were given isosorbide dinitrate (ISDN) 5 mg sublingually and serum concentrations of ISDN, 2-isosorbide mononitrate (2-ISMN) and 5-isosorbide mononitrate (5-ISMN) were measured, as well as changes in digital plethysmographic amplitude, heart rate, ECG, blood pressure and Schellong's test. ISDN was rapidly absorbed and metabolized, having an elimination half-life of 29 min. Its metabolites 2-ISMN and 5-ISMN had longer half-lives of 1.75 and 7.6 h respectively. The amplitude of the α-wave of the digital plethysmograph did not change significantly either in the predrug period or after placebo administration. It increased within 4 min of administration of ISDN, and reached a maximum after 14 min; the effect lasted for about 2 h. ISDN lowers blood pressure and increases heart rate in most volunteers, but in 3 of the 18 subjects severe hypotension occurred, accompanied by severe, reversible bradycardia, which was probably due to vagal reflexes initiated by the markedly diminished ventricular enddiastolic volume (LVEDV) and pressure (LVEDP). No correlation could be demonstrated between the serum concentration of ISDN and/or its vasoactive metabolites and changes in plethysmographic amplitude.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00563005
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  • 19
    Electronic Resource
    Electronic Resource
    Clinical pharmacokinetics and oral bioavailability of ketobemidone (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 45-50 
    Details
    ISSN: 1432-1041
    Keywords: ketobemidone ; narcotic analgesic ; N,N-dimethyl-3,3-diphenyl-1-methylallylamine chloride ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The basic pharmacokinetics and oral bioavailability of ketobemidone have been studied in 6 patients after surgery. Plasma concentrations were first determined following intravenous administration of Ketogin® 2 ml, containing ketobemidone chloride 10 mg and the spasmolytic N,N-dimethyl-3,3-diphenyl-1-methylallylamine chloride 50 mg, and then, on the second postoperative day, following oral administration of 2 tablets of Ketogin®, each containing ketobemidone chloride 5 mg and the spasmolytic agent 25 mg. The average oral bioavailability of ketobemidone was 34%±16% (SD, n=6). The mean plasma half-life of elimination (t1/2β) was about the same following oral (2.45±0.73 h; SD, n=5) as after intravenous administration (2.25±0.35 h; SD, n=6). The low oral bioavailability and rapid elimination of ketobemidone demonstrated in this study suggest that the usual dosage recommendation for oral Ketogin® (ketobemidone 5–10 mg every 6–7 h) in patients with severe pain is too low.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561676
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  • 20
    Electronic Resource
    Electronic Resource
    A single and multiple dose pharmacokinetic and pharmacodynamic comparison of conventional and slow-release metoprolol (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 87-92 
    Details
    ISSN: 1432-1041
    Keywords: beta-blocker ; metoprolol ; slow-release formulation ; multiple dosing ; blood pressure ; heart rate ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Pharmacokinetic and pharmacodynamic profiles for metoprolol have been measured in six healthy volunteers after single and multiple dosing with 100 mg conventional formulation twice daily and 200 mg slow-release formulation once daily. Both multidose regimes produced measurable predosing plasma concentrations of metoprolol. The plasma concentrations on the eighth day were greater than predicted by the single-dose data as indicated by the comparison of the total areas under the curve for the single dose and the dosage interval areas during multiple dosing. This increase may be associated with a change in the bioavailability and/or clearance of the drug and is currently being investigated. The peak concentrations for the two regimens were comparable but the times to peak with the slow-release regimen were significantly delayed. Both regimes produced significant beta-blocking effects over 24 h during multiple dosing, the reductions in exercise heart rate at 0 and 24 h on the eighth day corresponding to more than 20% of the maximum effect. Resting pulse rates and blood pressures were affected to a similar extent by the two regimens but neither significantly altered respiratory peak flow rates. The effects during multiple dosing were generally greater than those after a single dose and appeared to follow a more consistent trend. This observation, together with those for the plasma level data on the eighth day, illustrate the importance of performing multiple-dose studies in assessing beta-blocking drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00562615
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  • 21
    Electronic Resource
    Electronic Resource
    Pharmacokinetic and clinical observations on prolonged administration of flunitrazepam (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 189-196 
    Details
    ISSN: 1432-1041
    Keywords: flunitrazepam ; prolonged administration ; pharmacokinetics ; clinical observations ; sleep parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Eight patients were given flunitrazepam 2 mg orally, once daily for 28 consecutive days. The time-course of the plasma concentration of unchanged flunitrazepam and its principal metabolites were studied in detail after the first and last doses. Additional blood samples were collected immediately before administration of the tablet on days 4, 7, 11, 14, 18, 21 and 25. Clinically there were no changes during the trial period in the onset of sleep, duration of sleep, depth of sleep measured as number of spontaneous awakenings, or in the patients' condition on awakening. The time-course of the plasma concentration of flunitrazepam could be described by a three-compartment model, assuming that the rate constants remained unchanged during treatment. Maximal plasma concentrations of unchanged flunitrazepam, found two hours after intake, reached 10–15 ng/ml after the first and 15–20 ng/ml after the last dose. The β-half-life was found to be between 20 and 36 h.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561899
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  • 22
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of chlormethiazole in healthy volunteers and patients with cirrhosis of the liver (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 275-284 
    Details
    ISSN: 1432-1041
    Keywords: chlormethiazole ; cirrhosis of the liver ; antipyrine ; protein binding ; pharmacokinetics ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of chlormethiazole after oral and intravenous administration was studied in six healthy volunteers and eight patients with alcoholic cirrhosis of the liver. Plasma concentration-time curve after the intravenous infusion could adequately be described by two- or three-compartment open models both in healthy volunteers and in the patients. Based on the areas under the plasma concentration-time curves, the systemic bioavailability of oral chlormethiazole was about ten times greater in the patients than in healthy controls. The elimination of chlormethiazole was relatively less retarded in the patients, as indicated by a decrease of about 30% in its plasma clearance. In the patients the plasma protein binding of chlormethiazole was decreased, but the volume of distribution and half-life of elimination were unchanged. The increase in bioavailability of chlormethiazole was associated with significant alteration in the serum levels of bilirubin, albumin, alkaline phosphatase, prothrombin-proconvertin activity (P + P) and elimination rate of antipyrine or14C-aminopyrine. The increased bioavailability of oral chlormethiazole was due to impaired first-pass metabolism in the cirrhotic liver. A considerable reduction in dose seems to be indicated if oral chlormethiazole is used in patients with advanced cirrhosis of the liver. A substantial fraction of dose, averaging 15%, was lost during the intravenous infusion, presumably due to adsorption to the infusion tubing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00625801
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  • 23
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of naproxen in subjects with normal and impaired renal function (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 263-268 
    Details
    ISSN: 1432-1041
    Keywords: naproxen ; renal insufficiency ; metabolism ; protein binding ; single dose ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of naproxen after a single oral dose of 250 mg has been studied in 8 subjects with normal renal function and 16 patients with varying degrees of chronic renal insufficiency. Unchanged naproxen and its main unconjugated metabolite, 6-0-desmethylnaproxen, were determined fluorometrically in serum. In healthy subjects the elimination half-life of naproxen was 17.7± 3.0 h (mean±SD) and it was not significantly prolonged in patients with renal failure (18.1±5.3) h. No accumulation of naproxen in serum occurred in uraemic patients. On the contrary, serum drug levels were slightly but significantly lower in patients with severe renal failure. The total body clearance and apparent volume of distribution of naproxen were significantly increased in this group of patients. Decreased binding of naproxen to serum proteins was observed in patients with renal failure. The apparent half-life of desmethylnaproxen was of the same order of magnitude as that of naproxen (18.6± 4.4 h), and was also independent of renal function. A good correlation was found between the area under the curve (AUC), the peak concentration of the metabolite and the serum creatinine concentration. These observations suggest increased metabolism and an increased apparent volume of distribution of naproxen in severe renal failure, probably caused by decreased serum protein binding of the drug. However, it is proposed that in naproxen therapy no adjustment of the dosage regimen is necessary in patients with impaired renal function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00563009
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  • 24
    Electronic Resource
    Electronic Resource
    Pharmacokinetic studies in volunteers of intravenous and oral cis (Z)-flupentixol and intramuscular cis (Z)-flupentixol decanoate in viscoleo® (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 355-360 
    Details
    ISSN: 1432-1041
    Keywords: cis (Z)-flupentixol ; cis (Z)-flupentixol decanoate ; serum concentration ; biological half-life ; pharmacokinetics ; first-pass metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Serum concentrations of cis (Z)-flupentixol have been estimated in three male human volunteers who received cis (Z)-flupentixol by intravenous infusion, flupentixol (cis (Z)/trans (E) mixture, 1:1) orally as single and repeated doses, and i. m. cis (Z)-flupentixol decanoate in Viscoleo®. The intravenous data show that cis (Z)-flupentixol followed a multicompartment model, but it was not possible to fit the data to a two or three compartment model. The concentration curves after oral administration indicated relatively slow absorption with a peak concentration at 3–6 h, except for one case with peak at 1 h. The variation in the dosage interval after one daily oral administration was relatively limited (1.7–3.0 times), which indicates that 24 h is a reasonable dosage interval. Biological half-lives were estimated in different ways and showed some intra-individual variation; the half-life was of medium length (19–39 h). The serum concentrations after intramuscular injection of cis (Z)-flupentixol decanoate clearly demonstrated a depot effect, with a maximal concentration at 3–5 days after injection. The descending part of the serum curves allowed an approximate estimation of half-life of 3–8 days. This was not the elimination half-life, but in all probability the half-life of release of drug from the oil depot which was the rate-limiting step. From the areas under the serum concentration curves the fraction of orally administered cis (Z)-flupentixol available to the organism was calculated to be 55% (range 48–60%). The loss of drug might have been due to imcomplete absorption, but it is more likely that cis (Z)-flupentixol underwent first-pass metabolism in the gut wall and the liver. As the tablets contained about 50% cis (Z)-flupentixol, while the depot preparation contained 74% cis (Z)-flupentixol, the pharmacokinetically equivalent doses are: 10 mg tablet daily corresponds to 25 mg depot weekly. Calculation of systemic clearance gave values of 0.44–0.49 l/min, and an apparent volume of distribution was 12.5–17.2 l/kg.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561395
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  • 25
    Electronic Resource
    Electronic Resource
    Time-course of the anti-hypertensive action of atenolol: Comparison of response to first dose and to maintained oral administration (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 365-374 
    Details
    ISSN: 1432-1041
    Keywords: atenolol ; hypertension ; plasma renin activity ; pharmacokinetics ; pharmacodynamic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary To show whether repeated administration of atenolol for several days would influence its pharmacokinetic parameters and the extent and duration of the pharmacologic responses, the plasma level of atenolol and changes in heart rate, blood pressure and plasma renin activity were measured in 12 hypertensive patients at various times of day (9 a. m., 12 noon, 3 p. m. and 7 p. m.) after oral administration of the first dose of atenolol 100 mg, again during the 7th and 14th days of continued once-daily administration of the same dose, and finally during the three days following withdrawal of the drug. The peak plasma concentration of atenolol (about 600 ng/ml) was found 3 h after administration of the first dose, and measurable amounts (50–70 ng/ml) were found after 24 h. None of the pharmacokinetic characteristics were changed by administration of a single daily dose for two weeks. After withdrawal of the drug, detectable amounts of atenolol were found in plasma for at least 48 h. The first dose of atenolol caused prompt (3 h) and prolonged (up to 24 h) lowering of supine and standing systolic and diastolic blood pressures, slowing of supine and standing heart rate, reduction of the blood pressure and heart rate responses to dynamic exercise, and a decrease in plasma renin activity. The extent and time-course of all these responses were not influenced by repeated once-daily administration of the 100 mg dose for two weeks. Most of the effects continued during the withdrawal days, the lowering of blood pressure being somewhat more prolonged than the slowing of heart rate. It is concluded that a once-daily dose of atenolol 100 mg decreases blood pressure and heart rate throughout the following 24 h, without excessive daily fluctuation in its effects, and without signs of tolerance or accumulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636787
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  • 26
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of acebutolol in patients with all grades of renal failure (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 339-348 
    Details
    ISSN: 1432-1041
    Keywords: acebutolol ; renal failure ; dialysis ; pharmacokinetics ; N-acetylmetabolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of acebutolol was studied in 10 healthy subjects with normal renal function (RN), in 13 patients with various degrees of renal failure (RI) and in 8 patients undergoing repeated haemodialysis (RD). A highly specific method was used to measure acebutolol (A) and N-acetylmetabolite (NAM). In RN the decrease in plasma levels was biexponential with an apparent plasma half lives in the slow phase of A: 8.8±2.3 h and NAM: 11.4±2.2 h. The percentage of the dose excreted unchanged was 13.9% and as NAM 25.8%. Renal clearances were A: 167±20 ml/min and NAM: 150±18 ml/min. The apparent plasma half life of acebutolol does not change according to the degree of renal insufficiency (RI: 7.0±2.7 h, RD: 7.5±2.7 h), while that of NAM is increased (RI: 21.5±10.1 h, RD: 32.3±16.8 h). There is a linear relationship between the apparent elimination rate constant of NAM and creatinine clearance (r=0.832,p〈0.001). In RI 21.7% of the dose is excreted in urine (A 5.0%, NAM 16.7%). When renal function is impaired, the renal clearance of A and NAM decrease in parallel with the creatinine clearance (A: r=0.874,p〈0.001; NAM: r=0.954,p〈0.001). During dialysis the plasma half life fell (A=3.4±0.9 h, NAM=7.4±2.6 h). The dialytic clearance was A: 42.6±12.7 ml/min and NAM: 40.4±16.3 ml/min, for a blood flow of 238±35 ml/min through a dialyser with a cuprophane membrane (Ultraflo II Travenol). Acebutolol is taken up by erythrocytes (λbc=0.50±0.04). The results suggest that the dosage of acebutolol should be adjusted according to the degree of renal insufficiency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558446
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  • 27
    Electronic Resource
    Electronic Resource
    Disposition and clinical pharmacokinetics of microcrystalline theophylline (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 379-384 
    Details
    ISSN: 1432-1041
    Keywords: theophylline ; aminophylline ; obstructive lung disease ; microcrystalline ; bioavailability ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Variation in the systemic disposition of theophylline after ingestion of a new microcrystalline product (Theolair®) has been investigated in 7 hospitalized patients with generalized obstructive lung disease. Disposition (absolute bioavailability) was determined by comparing in the same patients the areas under the serum concentration-time curves after a single oral dose of microcrystalline theophylline and after an intravenous infusion of aminophylline. Oral absorption appeared to be fast. The half-life of absorption was 19±9 min (mean±SD). Maximal serum concentrations reached after 100±30 min were found to be in a rather narrow range: 9.8±2.5 mg · 1−1. The absolute bioavailability of the microcrystalline preparation was high and it showed only small variation: 102.7±10.2% of the dose. Relevant pharmacokinetic parameters (half-life of elimination, volume of distribution and total body clearance) were determined after both routes of administration. Individual dosage regimens required to obtain a therapeutic serum concentration were calculated for each individual patient on the basis of the observed pharmacokinetic parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558452
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  • 28
    Electronic Resource
    Electronic Resource
    Relationship of propranolol pharmacokinetics to antihypertensive effect and beta-adrenergic blockade in the treatment of hypertension (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 391-394 
    Details
    ISSN: 1432-1041
    Keywords: propranolol ; hypertension ; beta-adrenergic blockade ; exercise heart rate ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of propranolol in 16 hypertensive patients was compared after the first oral dose of 80 mg and during chronic treatment with 80 mg bd. The degree of beta-adrenergic blockade was estimated by the reduction in maximal exercise heart rate. No significant change in plasma half-life occurred and there was no correlation between the mean steady-state propranolol concentration and beta-adrenergic blockade or antihypertensive effect. A linear relationship was observed between the decrease in blood pressure and the reduction in heart rate during maximal exercise. Therefore, the antihypertensive effect of propranolol can be explained by its peripheral beta-adrenergic blocking properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636790
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  • 29
    Electronic Resource
    Electronic Resource
    Influence of food intake on the absorption and effect of glipizide in diabetics and in healthy subjects (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 279-283 
    Details
    ISSN: 1432-1041
    Keywords: glipizide ; diabetes ; food intake ; blood glucose ; blood insulin ; pharmacodynamics ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The influence of a standardized breakfast on the single dose (5 mg) kinetics and effects of glipizide was examined in 9 healthy volunteers and in 14 diabetics not previously exposed to a sulfonylurea. In the volunteers, glipizide caused an increase in plasma insulin and a reduction in blood glucose both during continued fasting and when the drug was taken with the breakfast. Food intake did not influence the peak concentration, the elimination half-life or the bioavailability of the drug. However, food intake significantly delayed the absorption of glipizide by about 0.5 h. In the patients, glipizide produced a significant increase in plasma insulin and a significant diminution of the rise in blood glucose in response to the meal. Starting at breakfast and for 45 min thereafter serum glipizide concentrations were significantly higher when the drug was taken 0.5 h before the meal, than when ingested concurrently with it. With the former treatment, the increase in plasma insulin occurred earlier and the blood glucose reduction was pronouncedly greater than with the latter treatment. As the absorption of glipizide may be delayed by concurrent breakfast, this may help to explain, why the administration of glipizide 0.5 h before breakfast led to a more appropriate relation between the serum concentration of the drug and the metabolic impact of the meal, thereby promoting more appropriate insulin release and better glucose disposition than after concurrent intake of the drug and breakfast.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00563012
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  • 30
    Electronic Resource
    Electronic Resource
    Disposition of dibekacin in patients undergoing haemodialysis (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 347-350 
    Details
    ISSN: 1432-1041
    Keywords: dibekacin ; renal failure ; dialysis ; pharmacokinetics ; microbiological assay ; dosage regimen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of Dibekacin were studied in 10 patients with terminal renal impairment (creatinine clearance 〈5 ml/min) undergoing haemodialysis sessions lasting 4 h. The dialyzers were either the Gambro Lundia Major 13.5 or the Ultra Flo II 1.4., and the patients were divided into two groups according to the dialyzer used. Blood flow varied between 250 and 280 ml/min and dialyzate flow between 450 and 600 ml/min. All patients received a single i. v. dose of Dibekacin 1.5 mg/kg at the beginning of the dialysis session. The concentration of the antibiotic at the input and the output of the dialyzer were determined microbiologically by a plate diffusion method usingB. subtilis as the test organism. The intravenously administered antibiotic followed an open two-compartment kinetic model. The type of dialyzer used did not influence the dialysis of Dibekacin. Haemodialysis significantly increased the elimination rate of the antibiotic with respect to the interdialysis periods. The plasma half-life in the slow disposition phase fell from 30 h in the interdialysis period to 4.0 h during dialysis sessions. From the calculated pharmacokinetic parameters, a dosage regimen for this kind of patient is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561393
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  • 31
    Electronic Resource
    Electronic Resource
    Haemodynamic effects, plasma concentrations and tolerance of orally administered prenalterol in man (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 383-390 
    Details
    ISSN: 1432-1041
    Keywords: prenalterol ; oxprenolol ; haemodynamics ; pharmacokinetics ; inotropic effects ; side effects ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Prenalterol was studied in six healthy volunteers given single oral doses of 2.5, 5 and 10 mg and placebo. It displayed a distinct positive inotropic action, manifested as a dose-related reduction of 16.5–27.2 msec in the pre-ejection period (PEPc; systolic time-intervals), and an increase of 4.2–5.9 Ω/sec2 in the Heather index (impedance cardiography). There was also a dose-related increase of 17.6–34.0 mmHg in systolic blood pressure, whereas diastolic pressure showed a slight, transient decrease, not related to the dose given. Heart rate rose by 5–12 beats/min. Stroke volume, as determined by impedance cardiography, increased by 24.2–28.5 ml at all three dose-levels. The effects of the drug developed rapidly, reaching their maximum within 30–60 min and lasting for about 4 h. The time-course of the effects corresponded to the plasma concentrations of the drug. The increases in systolic pressure and contractility were linearly correlated with the plasma concentrations (r=0.8−0.9,p〈0.001). The activity of prenalterol was also tested in the same volunteers after blockade of β-receptors with oxprenolol 80 mg. Under these conditions, oral doses of 25, 50 and 100 mg produced effects similar to or slightly less marked than those recorded after doses ten times lower in the absence of β-blockade. In a further 10 healthy volunteers, in whom tolerance to prenalterol was studied by repeated administration for 10 days of 5 mg four times daily, no change in blood chemistry, haematological parameters or urine values was found. The positive inotropic effect of a single oral dose of prenalterol 5 mg was also demonstrated by reference to the systolic time-intervals and the echocardiogram, in six patients with chronic heart failure, five of whom were digitalized. Prenalterol did not give rise to premature concentrations or other arrhythmias. The only untoward effect definitely attributable to the drug was palpitation, which was dose-related and as a rule was not unduly distressing; in one volunteer, however, the palpitations were unbearable. Prenalterol is a cardiostimulant agent with no direct effect on the peripheral circulation. On the basis of its pharmacological activity, it might well be of therapeutic benefit in all conditions in which an improvement in the pumping efficiency of the heart is required.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636789
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  • 32
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of ketoprofen following single oral, intramuscular and rectal doses and after repeated oral administration (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 407-414 
    Details
    ISSN: 1432-1041
    Keywords: ketoprofen ; pharmacokinetics ; relative bioavailability ; single doses ; repeated doses ; prediction of kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of ketoprofen was studied in the same healthy subjects after single oral, intramuscular and rectal doses, and after repeated oral administration. No significant difference in the mean t1/2 (1.13–1.27 h) was observed after the different modes of administration. The mean [AUC] 0 ∞ after rectal administration of a suppository showed the minimum significant difference (p〈0.05) from that after oral administration of the capsule. The apparent volume of distribution (Vd/F) was approximately 10–15% of body weight. The renal contribution (mean, 0.10–0.15 ml/min/kg) to the plasma clearance of free ketoprofen was assumed to be, at most, 8.3–12.9%. The projected cumulative excretion of total (free plus conjugated) ketoprofen via urine exceeded 63–75% of the dose, of which approximately 90% was ketoprofen glucuronide. A mean of 71–96% and 73–93% of the oral capsule was estimated to be systemically available after administration of the intramuscular preparation and rectal suppository, respectively. In four of seven subjects, CPK concentration was elevated after the intramuscular injection. The mean steady-state concentration of ketoprofen in plasma ranged from 0.43 to 5.62 µg/ml after the final dose of a 50 mg q.i.d. regimen. The disposition data and plasma levels observed at steady-state were in agreement with those predicted from the single oral dose study. The accumulation ratio was 1.08±0.08. The results suggest that the rectal suppository can be recommended as an extravascular mode of administration of this drug.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00636794
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  • 33
    Electronic Resource
    Electronic Resource
    Inhibition by idrocilamide of the disposition of caffeine (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 37-43 
    Details
    ISSN: 1432-1041
    Keywords: caffeine ; idrocilamide ; xanthine derivatives ; inhibition of metabolism ; neuropsychiatric side effects ; pharmacokinetics ; healthy man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of caffeine are greatly altered by concomitant administration of idrocilamide. In four healthy volunteers id rocilamide inhibited the biotransformation of caffeine and increased its half-life nine times. The untoward neuropsychiatric effects of idrocilamide are the consequence of abnormal accumulation of caffeine in regular consumers of caffeine-containing foods and beverages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561675
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  • 34
    Electronic Resource
    Electronic Resource
    Altered prazosin pharmacokinetics in congestive heart failure (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 425-428 
    Details
    ISSN: 1432-1041
    Keywords: prazosin ; congestive heart failure ; pharmacokinetics ; oral dose ; comparison with healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of prazosin (Minipress®) were studied in nine patients with NYHA Class 3 or 4 congestive heart failure and in five healthy controls. After a single 5 mg oral dose, plasma concentrations of prazosin, as reflected in the area under the plasma concentration-time curve (AUC) and prazosin plasma half-life, were approximately double in the patients in comparison to the control group. Reduction in hepatic blood flow, altered gastrointestinal absorption of the drug or diminished intrinsic hepatic metabolic activity in the patient group may have contributed to the observed changes in prazosin disposition. The finding of higher prazosin plasma concentrations in patients with refractory heart failure demonstrates the need for close monitoring of these individuals following administration of the drug in the treatment of chronic congestive heart failure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00570159
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  • 35
    Electronic Resource
    Electronic Resource
    Placental transfer of pethidine and norpethidine and their pharmacokinetics in the newborn (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 25-30 
    Details
    ISSN: 1432-1041
    Keywords: pethidine ; norpethidine ; placental transfer ; pharmacokinetics ; newborns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The literature data available on pethidine and norpethidine kinetics in women in labour and in their newborns is reviewed and compared with recent personal observations. In pregnant women the apparent blood half-life of pethidine is not different from that in healthy controls, however, apparent volume of distribution and total body clearance are reduced. Norpethidine blood levels are measurable after 10–20 min and tend to increase with time. The amount of drug transferred to the foetus is clearly linked to the dose administered to the mother, the dosing-delivery interval and to the metabolic capability of the mother. An equilibrium between maternal and umbilical venous blood is reached 2–3 h after dosing for pethidine and later for norpethidine. In the neonate, the apparent pethidine half-life is 2 to 7 times longer than in adults with values ranging from 7 to 32 h. Norpethidine is actively formed in the newborn with peak blood levels at 12–36 h and an apparent blood half-life of 20–36 h. At the doses usually recommended blood concentrations at birth are frequently higher than those required for analgesia and close to or within toxic ranges. An effort toward a more individualized dosage as well as toward a better understanding of the possible role of norpethidine with regard to adverse effects is needed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561475
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  • 36
    Electronic Resource
    Electronic Resource
    Disposition and pharmacodynamics of diuretics and antihypertensive agents in renal disease (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 109-116 
    Details
    ISSN: 1432-1041
    Keywords: diuretics ; antihypertensive agents ; renal disease ; dispositon ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacodynamic actions and disposition of diuretic and antihypertensive agents may be significantly modified in subjects with renal disease. Most studies on this question have dealt with alterations in the elimination kinetics of these drugs and, while they generate descriptive data, minimal insight about changes in dose-response relationships or mechanisms of drug action are provided by such investigations. Several basic principles which may serve as useful guidelines in determining how renal failure will influence the response to drugs have been considered. They include the following: degree of renal malfunction, intrinsic toxicity of the drug, alternative pathways for drug metabolism and elimination, elimination pharmacokinetics and dose-response characteristics. Several classes of diuretic agents (thiazides, furosemide) and antihypertensive drugs (hydralazine, methyldopa, propranolol, prazosin, and clonidine) have been used as models to define how basic knowledge of renal and non-renal pathways for elimination of drugs and their pharmacodynamic actions may assist in establishing rational therapeutic regimens for these agents in patients with renal failure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561487
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  • 37
    Electronic Resource
    Electronic Resource
    Bromocriptine concentration in saliva and plasma after long-term treatment of patients with Parkinson's disease (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 171-174 
    Details
    ISSN: 1432-1041
    Keywords: bromocriptine ; Parkinson's disease ; plasma level ; salivary level ; protein binding ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Salivary and plasma concentrations of bromocriptine (BCT), a dopamine agonist, were measured by gas chromatography in four patients with Parkinson's disease. All the patients had been on mono-therapy with BCT for years, and during the 3 weeks prior to the investigation they received constant but individually different dosage regimens. Paired samples of pure, parotid, serous saliva and of blood were collected hourly during one eight hour dose interval. The concentrations of BCT in saliva were very low and there was a ten-fold range in the areas under the salivary and plasma concentration/time curves. It is concluded that in clinical practice measurement of BCT in saliva is not suitable for exact estimation of the plasma concentration of BCT. Using the measured salivary pH and the plasma BCT concentration, calculations based on the Henderson-Hasselbalch equation showed that the assumption of about 99% plasma protein binding of BCT best fited the observed concentrations of BCT in saliva.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561586
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  • 38
    Electronic Resource
    Electronic Resource
    Comparative in vitro effects and in vivo kinetics of antithyroid drugs (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 295-299 
    Details
    ISSN: 1432-1041
    Keywords: propylthiouraci ; propranolol ; carbimazole ; methimazole ; comparative activity ; pharmacokinetics ; bioactivation ; thyroid peroxidase inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The in vitro effects of equimolar concentrations (0.1, 0.33 and 1.0 mmol/l) of carbimazole, methimazole, propylthiouracil and propranolol on thyroid peroxidase activity were studied on thyroid tissue specimens obtained from euthyroid patients undergoing parathyroidectomy. In addition, the in vivo kinetics of methimazole following single dose administration (60 mg) of carbimazole and of methimazole itself were examined in 11 healthy volunteers using high-pressure liquid chromatography to measure serum methimazole. The in vitro studies were carried out at pH 6, to avoid alkaline hydrolysis of carbimazole to methimazole. Under these conditions, methimazole strongly inhibited thyroid peroxidase. Propylthiouracil had a less pronounced inhibitory effect, and carbimazole was almost and propranolol was entirely inactive. The in vivo kinetics of methimazole showed a large interindividual variation. Within individuals, there was no significant difference in the half-life or time to peak concentration of methimazole following administration of carbimazole and methimazole, respectively. However, the peak concentration and area under the curve of methimazole were significantly greater after administration of methimazole itself than after administration of carbimazole. Assuming similar bioavailability, this difference could be related to the difference in molecular weight between carbimazole and methimazole. It appears that, in man, methimazole is the most active of antithyroid agents currently available, that carbimazole is essentially inactive per se but is bioactivated to methimazole, and that carbimazole offers neither dynamic nor kinetic advantages over methimazole.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00625803
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  • 39
    Electronic Resource
    Electronic Resource
    Time course of blood pressure, pulse rate, plasma renin and metoprolol during treatment of hypertensive patients (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 321-328 
    Details
    ISSN: 1432-1041
    Keywords: metoprolol ; hypertension ; pharmacokinetics ; plasma renin ; blood pressure effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Eleven patients were treated for essential hypertension with metoprolol (Selokén®) for more than three months. The time course of changes in blood pressure, pulse rate and plasma renin activity was studied during treatment with an oral maintenance dose of 100 mg twice daily. Significant decreases in pulse rate, diastolic blood pressure and plasma renin activity were observed even after the first dose. The plasma concentration of metoprolol reached equilibrium after the second dose. After the third dose there was no further significant change in blood pressure. There was a significant correlation (p〈0.001) between the initial (after three doses) and final (after 〉90days) effect of metoprolol on blood pressure (r=0.86 and 0.91 for systolic and diastolic blood pressure change, respectively).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558443
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  • 40
    Electronic Resource
    Electronic Resource
    Influence of dose on the pharmacokinetics of Cefadroxil (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 505-509 
    Details
    ISSN: 1432-1041
    Keywords: cefadroxil ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of Cefadroxil have been studied in a crossover study involving 20 experiments in four healthy volunteers (19–24 years), after oral administration of five individual doses of 250, 500, 750, 1000 and 1500 mg of the antibiotic in capsules to each person. Plasma and urine concentrations of the antibiotic were determined microbiologically by a plate diffusion method. The antibiotic followed an open, single-compartment kinetic model. The plasma half-life was not significantly influenced by dose; the average was 1.438±0.220 h. The percentage of the antibiotic excreted in urine, too, was not significantly affected by the dose, being close to 80% of the quantity originally administered within 24 h. The values of Cmax and (AUC) increased linearly with the administered dose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874664
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  • 41
    Electronic Resource
    Electronic Resource
    Comparative bioavailability of disopyramide after multiple dosing with standard capsules and controlled-release tablets (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 209-213 
    Details
    ISSN: 1432-1041
    Keywords: disopyramide ; bioavailability ; controlled-release tablets ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma concentrations and bioavailability of disopyramide following repeated administration of standard capsules and controlled-release tablets have been compared. Ten patients were randomized into two groups; Group I received disopyramide capsules 150 mg every 6 h for five days and subsequently disopyramide controlled-release tablets 300 mg every 12 h for further five days. Group II received the same preparations in the reverse order. There was a more rapid rise in disopyramide concentration after the capsules: the maximum of 10.7±0.6 µmol/l (mean ± SEM) was reached within 1.8±0.4 h as compared to 10.6±0.4 µmol/l within 4.0±0.3 h after the controlled-release tablets. No significant difference in the fluctuations in individual plasma concentrations during each dose interval at steady state were observed after ordinary capsules compared to controlled-release tablets. The extent of bioavailability was the same. Eight patients reported some side-effects during the capsule period and nine during the controlled-release tablet period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561902
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  • 42
    Electronic Resource
    Electronic Resource
    Systemic availability of orally administered L-dopa in the elderly Parkinsonian patient (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 215-221 
    Details
    ISSN: 1432-1041
    Keywords: L-dopa ; elderly ; pharmacokinetics ; bioavailability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Previous studies have suggested that the absorption of L-dopa in the elderly Parkinsonian patient might be unusually efficient. In the present investigation, the systemic availability of L-dopa was examined in 5 elderly Parkinsonian patients (mean age=77 years) and 6 young, healthy volunteers (mean age=26 years) following a single oral 300 mg dose of L-dopa. Quantitation of plasma levels of intact L-dopa was effected by ion-exchange column chromatography and spectrofluorimetry. The L-dopa plasma concentration-time profiles obtained confirmed the considerable intersubject variability in the absorption of L-dopa previously reported in the literature. Maximum plasma concentrations of L-dopa generally occurred within 60 min of administration of the dose. The existence of more than one plasma peak of L-dopa concentration was displayed in 45% of the subjects studied. This characteristic was not confined exclusively to either subject group. There was a significantly larger (P〈0.02) area under the plasma L-dopa concentration-time curve (AUC o ∞ ) in the elderly Parkinsonian patients (mean=234.69 µg · min/ml; SD=84.70) compared to the young, healthy volunteers (mean=82.33 µg · min/ml; SD=31.00). A significant (P〈0.01) correlation existed between AUC o ∞ and age (r=0.7970; n=11) among the subjects studied. The apparent elimination phase plasma half-life of L-dopa in the elderly Parkinsonian patients (mean=66.0 min; SD=11.1) was not significantly different to that observed in the young, healthy volunteers (mean=74.0 min; SD=18.1). These results suggest that there may be an age-related alteration to the disposition of orally administered L-dopa in the elderly Parkinsonian patient.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561903
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  • 43
    Electronic Resource
    Electronic Resource
    The pharmacokinetics of intravenous and oral sulpiride in healthy human subjects (1980)
    Springer
    European journal of clinical pharmacology 17 (1980), S. 385-391 
    Details
    ISSN: 1432-1041
    Keywords: sulpiride ; pharmacokinetics ; serum clearance ; renal clearance ; bioavailability ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of sulpiride was studied in 6 healthy volunteers after intravenous and oral (tablets) administration of 100 mg. An open two- and in two subjects a three-compartment model was applied following intravenous administration. The average total distribution volume during the terminal slope was 2.72±0.66 l/kg and total systemic clearance was 415±84 ml/min. The serum half-life of the terminal slope following intravenous administration averaged 5.3 h (range 3.7–7.1 h) according to the two-compartment model. In two subjects the half-lives were 11.0 and 13.9 h when the three-compartment model was applied. Determination of urinary excretion rates of unchanged sulpiride indicated a half-life of 7.15 h. Following intravenous administration, 70±9% of the dose was recovered unchanged in urine within 36 h; the mean renal clearance was 310±91 ml/min. Sulpiride was absorbed slowly, with peak concentrations appearing between 3 and 6 h after oral administration. The recovery of unchanged drug in urine following oral administration was 15±5% of the dose, with a mean renal clearance of 223±47 ml/min. The bioavailability determined from combined plasma and urine data was only 27±9%. The low bioavailability was probably due to incomplete absorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00558453
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  • 44
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and dosage of digoxin in neonates and infants (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 69-74 
    Details
    ISSN: 1432-1041
    Keywords: digoxin ; neonates ; infants ; pharmacokinetics ; dosage schedules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary As a therapeutic principle, a disease should be treated with the lowest effective dose of a drug. Accumulating information indicates that satisfactory contractile response of the myocardium is produced in young paediatric patients by doses of digoxin below existing recommendations. In addition, toxicity appears to be more frequent in neonates and infants treated with digoxin than previously thought. Therefore, dose calculations have been performed, based on pharmacokinetic parameters, with the aim of reaching and maintaining an average serum concentration of the glycoside of 2 nmol/l. This level is common in infants (〉1 month of age) during digoxin maintenance therapy and its adequacy is well supported by experience from adult cardiac patients. The calculations show that although current dosage schedules maintain the desired digoxin serum level in infants, they are often excessive for digitalization purposes. In neonates, the prevailing schemes do not sufficiently consider the immature state of the eliminating organs. Overdigitalization could therefore easily occur and continue in these patients, particularly in the premature newborns. This is in agreement with toxicity reports in the literature. The calculated doses should be less hazardous by being better adapted to the eliminating capacity of the various paediatric age-groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561481
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  • 45
    Electronic Resource
    Electronic Resource
    Effectiveness and pharmacokinetics of indomethacin in premature newborns with patent ductus arteriosus (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 83-88 
    Details
    ISSN: 1432-1041
    Keywords: patent ductus arteriosus ; indomethacin ; premature newborns ; pharmacokinetics ; side effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A review of the published data on pharmacological closure of PDA in premature newborns shows that doses of 0.2 mg/kg indomethacin are less successful when given enterally (18 to 85% closure) than when given intravenously (88 to 90% closure). The elimination half-life is markedly prolonged in premature newborns compared to adults but there are wide differences between the patients and some discrepancies between mean values reported by various authors. The present study compares clinical and pharmacological results obtained in two groups of low birth weight infants with symptomatic PDA and treated with 0.2 mg/kg indomethacin: 7 patients treated enterally (group A) and 11 patients treated intravenously (group B). Permanent closure of the ductus was observed in 4 cases in group A and in 9 cases in group B. Transient closure was observed twice in each group. Of a total of 18 infants, 15 were saved (83%). One baby treated with indomethacin in spite of preexisting oliguria died from persistent anuria. Indomethacin plasma levels were measured by gas chromatography. The mean elimination half-life of the drug in group A (40.3±12.2 h) did not differ from that in group B (33.9±11.7 h). The apparent plasma half-life appears to be inversely correlated with gestational age (r=0.66,p〈0.05). No relationship between peak plasma levels and ductal closure was established, but a significant difference was found for area under the curve (0 to 24 h) between patients in whom a permanent closure was obtained and those in whom the closure was either transient or absent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561483
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  • 46
    Electronic Resource
    Electronic Resource
    Nortriptyline therapy in elderly patients: Dosage prediction after single dose pharmacokinetic study (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 147-150 
    Details
    ISSN: 1432-1041
    Keywords: antidepressant ; geriatric ; nortriptyline ; pharmacokinetics ; prediction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Sixteen depressed elderly patients in hospital (mean age 81 years) received a single oral dose of nortriptyline prior to commencing treatment with this drug. Plasma nortriptyline measurements after the single dose were used to calculate the plasma drug clearance and to predict the daily dose required for each patient to achieve a steady-state concentration within the suggested therapeutic range of 50–150 µg·l−1. Using these dosage regimes, the mean observed steady-state concentration showed a significant correlation with the predicted values (r=0.71, p〈0.002). All patients had steady-state concentrations within or very close to this suggested range (mean 106, range 38–157 µg·l−1). Use of the prediction test can prevent the development of toxic plasma concentrations and enhance the possibility of therapeutic success. Our findings suggest that a safe starting dose of nortriptyline for the elderly is 30 mg per day.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561582
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  • 47
    Electronic Resource
    Electronic Resource
    Effect of posture and sleep on pharmacokinetics (1980)
    Springer
    European journal of clinical pharmacology 18 (1980), S. 175-183 
    Details
    ISSN: 1432-1041
    Keywords: amoxycillin ; pharmacokinetics ; bedrest ; sleep ; ambulation ; renal clearance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of amoxycillin in normal male volunteers was studied during the states of bedrest, sleep and ambulation. The absorption and disposition of amoxycillin in ambulatory subjects was found to be comparable to that reported previously by other workers. Serum amoxycillin concentrations were found to be significantly greater during ambulation than during bedrest and sleep. The difference in serum levels resulted from an increased apparent total serum clearance and amoxycillin renal clearance during bedrest and sleep compared to ambulation. No significant differences in the clearance was found between the states of bedrest and sleep. The change in renal clearance of amoxycillin during ambulation was attributed to a diminished renal blood flow. Although the terminal half-life of amoxycillin did not differ significantly, the apparent volume of distribution appears to be much greater during bedrest and sleep than during ambulation. This difference could be explained pharmacokinetically using a two compartment model. No significant difference was found between the rates of absorption of amoxycillin as reflected by the lag time and time to peak serum amoxycillin. The actual values for these parameters would suggest, however, that the absorption of amoxycillin is faster during ambulation than in bedrest and that the absorption rate during sleep is slowest. The clinical implications of the effect of posture and sleep on the pharmacokinetics of amoxycillin are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00561587
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  • 48
    Electronic Resource
    Electronic Resource
    Use of an (n, α) nuclear reaction to study the long-distance transport of boron in trifolium repens after foliar application (1980)
    Springer
    Planta 150 (1980), S. 197-205 
    Details
    ISSN: 1432-2048
    Keywords: Boron ; Foliar nutrition ; Nuclear reactions ; Transport (boron) ; Trifolium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of white clover (Trifolium repens L.) is severely inhibited by boron starvation, but a foliar treatment with boric acid can transitorily alleviate the deficiency symptoms. The 10B(n ,α)7 Li nuclear reaction has been used to study boron transport in the plant after foliar application. More than 98% of the boron supplied remained at the point where it was applied to the leaves, and less than 2% was useful to the growth of the treated plant. This small “efficient” portion of boron was quite mobile. It was distributed to the different parts of the plant, then was transferred from the oldest parts to the newly formed leaves. Physiological and agronomical implications of these data are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00390826
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  • 49
    Electronic Resource
    Electronic Resource
    Symbols in pharmacokinetics (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 497-507 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; symbols ; notation ; nomenclature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract To encourage uniformity in the presentation of pharmacokinetic data, a general nomenclature has been developed. The system has wide application. Flexibility is achieved through the use of general variables, constants, qualifying terms, and subscripts. Yet, through the use of implied terms, the symbols describing many common variables and constants are simple.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059548
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  • 50
    Electronic Resource
    Electronic Resource
    Identifiable pharmacokinetic models: The role of extra inputs and measurements (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 633-648 
    Details
    ISSN: 1573-8744
    Keywords: compartmental analysis ; dynamic response ; identification ; linear systems ; modeling ; parameter estimation ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Single input, single output experiments can result in nonunique solutions for the rate constants of a linear compartmental model used to describe the pharmacokinetics. Where a finite number of solutions exists, a priori knowledge has to be used to distinguish between the solutions. Where there is an infinite number of solutions, assumptions have to be made about the values of some rate constants in order to obtain a unique solution for the others. This paper considers such experiments and determines whether either the addition of an extra input (simultaneously with the first input) or the taking of an extra measurement would result in a unique solution. It is found that perturbing a second input can be useful, but only if the perturbation is of different shape from the first input. Measurements of drug in urine and metabolite in plasma are generally not helpful in resolving identifiability of the drug dynamic model. If a radioactive tracer is used, though, the second measurement (for example, by externally scanning the radioactivity of the liver) can prove useful, but only if the gain of the measuring device is known.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01060058
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  • 51
    Electronic Resource
    Electronic Resource
    Accumulation in the peripheral compartment of a linear two-compartment open model (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 99-104 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; pharmacological effects ; two-compartment model ; tissue accumulation ; aminoglycoside antibiotics ; gentamicin ; nephrotoxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Accumulation factors for the peripheral compartment in a two-compartment open model are derived. These expressions are contrasted with some previously published statements concerning drug accumulation. The utility of the new indices of accumulation is illustrated by reference to studies of gentamicin tissue uptake and its proposed relation to nephrotoxicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059451
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  • 52
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    Electronic Resource
    Pharmacokinetics of intravenously administered bumetanide in man (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 219-228 
    Details
    ISSN: 1573-8744
    Keywords: bumetanide ; diuretics ; pharmacokinetics ; three-compartment model ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Disposition of [ 14C] bumetanide administered intravenously to four healthy volunteers could be described by a triexponential equation. The mean half-lives associated with each exponent were 5.9 min, 46 min, and 3.1 hr, respectively. The largest fraction of dose was eliminated during the second phase; only 17% was eliminated during the last phase. The total plasma clearance averaged 228 ml/min, with renal clearance about one-half of this value. The recovery of unchanged bumetanide in urine over 2 days was 47% of the dose, while the total recovery of radioactivity in urine averaged 82% of dose. In plasma 93% of bumetanide was bound to proteins. Thus bumetanide is rapidly eliminated by both renal and nonrenal mechanisms. The elimination kinetics resembled those described for furosemide.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059643
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  • 53
    Electronic Resource
    Electronic Resource
    Pharmacokinetics of bretylium in man after intravenous administration (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 363-372 
    Details
    ISSN: 1573-8744
    Keywords: bretylium ; pharmacokinetics ; healthy subjects ; antiarrhythmic ; twocompartment model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetic profile of bretylium was studied in four normal male volunteers using a new sensitive EC-GC procedure for its quantitation in biological fluids. The plasma concentrations and urinary excretion rates following the constant i.v. infusion of a single 4mg/kg dose of bretylium tosylate declined biexponentially and the data were fitted to a two-compartment model with a renal and a nonrenal route of elimination. The drug had a mean half-life (t1/2β)of 7.8 hr and apparent volume of distribution (Vd,β)of 8.18 liters/kg. The renal clearance, which was 6 times that of the glomerular filtration rate, accounted for almost 84% of the total body clearance and correlated linearly with the subjects' creatinine clearance. The observed side effects of bretylium were mild and similar to those of other adrenergic blocking agents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059384
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  • 54
    Electronic Resource
    Electronic Resource
    Influence of renal failure on the hepatic clearance of bufuralol in man (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 421-438 
    Details
    ISSN: 1573-8744
    Keywords: bufuralol ; renal failure ; pharmacokinetics ; metabolites ; renal clearance ; hepatic clearance ; first-pass metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The beta-blocking agent bufuralol is subject to first-pass metabolism and is eliminated from the body almost entirely by biotransformation. Its major metabolite in plasma (1′-hydroxy-bufuralol) is biologically active and may contribute to the pharmacological effect of the drug. The effect of renal failure on the behavior of the parent compound and three of its metabolites was studied by comparing their kinetics in normal volunteers and in patients with severe renal insufficiency. Bufuralol was given orally to all subjects (20 mg); some of the healthy volunteers also received the drug intravenously (5 mg). Renal failure was found to be associated with a marked increase of the areas under the plasma concentration-time curves of the parent compound, whereas its halflife of elimination was not markedly influenced. The behavior of 1′-hydroxy-bufuralol was consistent with a decreased renal clearance. The behavior of bufuralol in patients with renal failure was analyzed using the clearance approach. From this analysis it appears that the presystemic biotransformation of bufuralol is decreased in renal failure and that changes in systemic clearance are compensated in our patients by modifications of the volume of distribution, resulting in little net change in the halflife of elimination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059544
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    Electronic Resource
    Lithium pharmacokinetics: Single-dose experiments and analysis using a physiological model (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 439-461 
    Details
    ISSN: 1573-8744
    Keywords: lithium ; pharmacokinetics ; physiological parameters ; cellular transport ; three-compartment model ; circadian rhythm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of lithium (Li +) distribution after a single dose was studied in healthy human subjects. Experiments were performed by simultaneously following changes of Li+ concentration in plasma, erythrocytes (RBC), and urine. The data were fitted by a simple but physiologically realistic model, so that extracted rate constants could be assigned to real body compartments and compared with independent measurements of cellular transport characteristics. The extracted rate constants were used to calculate steady-state cell-to-plasma Li+ ratios for RBC and for inaccessible cells (mainly muscle). In both cell types, the intracellular Li+ concentration is far below electrochemical equilibrium. This finding suggests that the Li+ countertransport efflux mechanism of RBC may be shared with muscle. We also present evidence for a circadian rhythm in Li+ excretion that parallels the daily cycle of Na+ and K+ excretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059545
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  • 56
    Electronic Resource
    Electronic Resource
    A pharmacokinetic model-independent approach for estimating dose required to give desired steady-state trough concentrations of drug in plasma (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 105-110 
    Details
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; maintenance dose ; dose estimation ; multiple dosing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A maintenance dose designed to give a desired minimum concentration of drug in plasma at steady-state can be determined in a model-independent manner assuming that concentration-time data needed for the calculation are obtained after absorption and distribution are complete. Using a few concentration-time points obtained after the first dose, numerical values of β and Z, a parameter consisting of different pharmacokinetic parameters for different models, can be obtained. An administration interval (τ) can be chosen based on β. Using the values of β, Z, and τ, a maintenance dose is calculated. This approach will allow calculation of a maintenance dose when drug is present in plasma at the time the first monitored dose is given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059452
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  • 57
    Electronic Resource
    Electronic Resource
    Heuristic modeling of drug delivery to malignant brain tumors (1980)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 8 (1980), S. 257-296 
    Details
    ISSN: 1573-8744
    Keywords: chemotherapy ; pharmacokinetics ; brain tumors ; modeling ; solid tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It is apparent that chemotherapy against malignant brain tumors is generally ineffective. While some agents are more effective than others, none appreciably alters the clinical course of and the poor prognosis for patients with brain tumors. Even though new and more effective agents are being or will be developed, chemotherapy depends as much on the delivery of drug as it does on the drug used. Therefore, we have defined factors that we believe are of primary importance in drug delivery to brain tumors, and, using computer simulation, we have modeled the effects of these factors. In this article we discuss (a) the extent of the “breakdown” in the blood-brain barrier (BBB) that accompanies the development of malignant tumors in the brain, (b) factors that influence drug transport from tumor capillaries to tumor cells at varying distances from the capillaries, (c) the problems inherent in drug delivery from a well-vascularized tumor outward to normal brain tissue that might harbor malignant cells but that does not have leaky vessels (i.e., normal BBB), and (d) the difficulties in drug delivery from a well-perfused, highly permeable outer tumor shell to a central, poorly perfused tumor core.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01059646
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  • 58
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    2,2-Disubstituierte 1,3-Dithiane aus β-Dicarbonylverbindungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 800-805 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2,2-Disubstituted 1,3-Dithianes from β-Dicarbonyl Compounds1,3-Dicarbonyl compounds 2 can be condensed with 1,3-propanedithiol (1) to yield 2,2-disubstituted 1,3-dithianes 3 which are remarkably stable in contrast to analogous open-chain thioacetals 6. Compounds with alkoxycarbonyl functions are easily hydrolysed to the corresponding carboxylic acids 11 which by further esterification with alkanols 12 yield estermodified 1,3-dithianes 3. All new compounds are characterized by 13C NMR spectroscopy.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130238
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  • 59
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    Perchlor-2-methylen-2H-pyran (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 806-807 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Perchloro-2-methylene-2H-pyranThe synthesis of the title compound 4 is described. 4 is thermally and chemically very stable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130239
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  • 60
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    Anchimer beschleunigte Homolysen, V. Thermische und Fluoridionen-katalysierte Umlagerungen von Benzyl)-[9-(trimethylgermyl)-9-fluorenyl]-ether (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 808-810 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Anchimerically Enhanced Homolyses, V. Fluoride Ion Catalysed Rearrangements of Benzyl 9-(Trimethylgermyl)-9-fluorenyl EtherThe thermal rearrangement (homolysis) of the germanium compound 1d into 4d is considerably slower than that of the analogous Si compound 1c. Thus, a correlation is suggested between the velocity of the rearrangement and the strength of the new bond to oxygen. The rearrangement 1d→4d is also induced by fluoride ions at room temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130240
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  • 61
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    Electronic Resource
    Masthead (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130301
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  • 62
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    Thion- und Dithioester, XXII. α,β-Ungesättigte Thion- und Dithioester (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 919-933 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiono and Dithio Esters, XXII. α,β-Unsaturated Thiono and Dithio Estersα,β-Unsaturated thiono and dithio esters such as O-ethyl thiocinnamate (3), methyl dithiocinnamate (7), O-ethyl thiocrotonate (17), and O,O-diethyl dithiofumarate (28) have been prepared by thiolysis between 20 and -75°C from the corresponding O- or S-alkylated tertiary amides or thioamides. They tend to dimerize in part by [4 + 2] cycloadditions. Methyl dithiocrotonate (24) could only be isolated as the endo-dimer 25.
    Notes: α,β-Ungesättigte Thion- und Dithioester wie Thiozimtsäure-O-ethylester (3), Dithiozimtsäure-methylester (7), Thiocrotonsäure-O-ethylester (17) und Dithiofumarsäure-O,O-diethylester (28) sind durch Thiolyse aus den entsprechenden O- oder S-alkylierten tertiären Amiden oder Thio-amiden bei Temperaturen von 20 bis -75°C zugänglich. Sie dimerisieren zum Teil in [4 + 2]-Cycloadditionen. Dithiocrotonsäure-methylester (24) ist nur als endo-Dimeres 25 erhältlich.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130312
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  • 63
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    Zur Thermolyse von Verbindungen mit geometrisch fixierter Vinyloxiran-Einheit: Stereospezifische Synthese von 4,5-anellierten cis- und trans-2,3-Dihydrofuranen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 875-901 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of Compounds with a Geometrically Fixed Vinyloxirane Unit: Stereospecific Synthesis of 4,5-Fused cis-and trans-2,3-DihydrofuransThe conformationally fixed vinyloxiranes 7c - f, 8a - f, and 9b - d are transformed thermally into the bicyclic ethers 23 - 25. Starting with the spiro-derivatives c - f, which are monosubstituted at the vinyl group, the ring expansion takes place with high stereospecificity leading to 4,5-fused cis-(c/e) and trans-2,3-dihydrofurans (d/f), respectively. On heating 8b and 9b in the presence of dimethylfumarate besides the isomerisation to 24b/25b two cycloadducts are formed in each case to which the structures of 29/31 and 30/32 have been assigned. Oxapentadienyl dipoles (3) are proposed as intermediates in which the rotation of C/O-bonds is energetically more favorable than rotation of C/C-bonds. The activation parameters for the transformation 8b → 24b are determined and discussed together with the reported data of some analogous ring expansion reactions.
    Notes: Die konformativ fixierten Vinyloxirane 7c - f, 8a - f und 9b - d wandeln sich thermisch mit Ausbeuten zwischen 50 und 80% in die bicyclischen Ether 23 - 25 um. Ausgehend von den an der Vinylgruppe monosubstituierten Spiro-Derivaten c - f erfolgt die Ringerweiterungsreaktion mit hoher Stereospezifität zu 4,5-anellierten cis- (c/e) bzw. trans-2,3-Dihydrofuranen (d/f). Beim Erhitzen von 8b und 9b in Gegenwart von Fumarsäuredimethylester entstehen neben den Isomeren 24b bzw. 25b jeweils zwei Cycloaddukte im Verhältnis 10: 1, denen die Strukturen 29/31 und 30/32 zugeordnet werden. Als Zwischenstufen werden Oxapentadienyl-Dipole (3) angenommen, in welchen die Rotation um C/O-Bindungen energetisch günstiger ist als die um C/C-Bindungen. Die Aktivierungsparameter der Umwandlung 8b → 24b werden bestimmt und im Zusammenhang mit denen einiger analoger Ringerweiterungen diskutiert.
    Additional Material: 12 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130309
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  • 64
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    Electronic Resource
    Statistische Synthesen von Rotaxanen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 941-954 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Statistical Syntheses of RotaxanesThe acetalisation of the 28-membered cyclic diols 11a, b with the long-chain dibromo ketone 12 gives acetals 13a, b. These compounds react with triphenylmethyllithium to give 17a, b and 18a, b from which the rotaxanes 20a, b are obtained in 0.066 or 0.18 and 0.12% yield, respectively, after hydrolysis of the acetal bonds. The reacetalisation of rotaxane 20b affords, by an intraannular reaction, the prerotaxane 18b in pure form.
    Notes: Die Acetalisierung der 28-gliedrigen cyclischen Diole 11a, b mit dem langkettigen Dibromketon 12 ergibt die Acetale 13a, b. Nach Umsetzung mit Triphenylmethyllithium zu 17a, b und 18a, b werden nach Hydrolyse der Acetalbindungen die Rotaxane 20a, b in Ausbeuten von 0.066 und 0.18 bzw. 0.12% als farblose Öle isoliert. Durch Reacetalisierung von 20b wird in einer intraannularen Reaktion das Prärotaxan 18b in reiner Form erhalten.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130314
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  • 65
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    Umlagerung von α-Isocyanato-N2-(arylsulfonyl)amidinen in 1-Arylsulfonyl-3-imidazolin-2-one (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 934-940 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangement of α-Isocyanato-N2-(arylsulfonyl)amidines to 1-Arylsulfonyl-3-imidazolin-2-onesThe reaction of the azirines 1 with the isocyanates 2 leads to the α-isocyanato-N2-(arylsulfonyl)-amidines 6. Starting from 1b, also considerable amounts of 7b and 8b are formed as a result of a retro-ene reaction of 6b. The heterocumulenes 6 readily rearrange with a shift of the sulfonyl group to give the heterocycles 10. The mobility of the sulfonyl residue is also obvious from the reaction of 6a with hydrogen chloride to afford tosyl chloride and 8a as well as from the reaction with amines, which, however, does not only yield the tosylamides 15, but also the ureas 13 and their secondary products 14.
    Notes: Die Reaktion der Azirine 1 mit den Isocyanaten 2 führt zu den α-Isocyanato-N2-(arylsulfonyl)-amidinen 6. Ausgehend von 1b werden auch beträchtliche Mengen 7b und 8b als Folge einer Retro-En-Reaktion von 6b gebildet. Die Heterocumulene 6 lagern sich unter Wanderung der Sulfonyl-Gruppe leicht in die Heterocyclen 10 um. Die Beweglichkeit des Sulfonyl-Rests wird auch in der Reaktion von 6a mit Chlorwasserstoff zu Tosylchlorid und 8a sowie in der Umsetzung mit Aminen deutlich, die neben Tosylamiden 15 allerdings auch Harnstoffe 13 und deren Folgeprodukte 14 liefert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130313
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  • 66
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    Di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphan)-ruthenium(I)](Ru - Ru) (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 989-994 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphane)ruthenium(I)](Ru - Ru)Ru3(CO)12 reacts with tri-tert-butylphosphane and formic acid, acetic acid, propionic acid, butyric acid, or stearic acid to form di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphane)-ruthenium(I)](Ru - Ru). The IR and NMR spectroscopic data are discussed.
    Notes: Ru3(CO)12 reagiert mit Tri-tert-butylphosphan und Ameisensäure. Essigsäure, Propionsäure, Buttersäure oder Stearinsäure unter Bildung von Di-μ-(carboxylato)-bis[dicarbonyl(tri-tert-butylphosphan)ruthenium(I)](Ru - Ru). Die IR- und NMR-spektroskopischen Daten der neuen Komplexe werden diskutiert.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130318
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  • 67
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    Addition von Aldehyden an aktivierte Doppelbindungen, XXIII. Synthesen von 1,3,6-Triketonen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 979-988 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Aldehydes to Activated Double Bonds, XXIII. Syntheses of 1,3,6-TriketonesThiazolium salt-catalyzed addition of aldehydes to monoacetals of vinyl-1,3-diketones (1, 2; 23, 24) leads to 1,4-diketones (3 - 10; 25 - 31), which are hydrolyzed to 1,3,6-triketones (11 - 18; 32 - 38). A way to the mono-acetalized vinyl-1,3-diketones 1, 2; 23, 24 using the norbornenyl group with following pyrolysis is given.
    Notes: Thiazoliumsalz-katalysierte Additionen von Aldehyden an mono-acetalisierte Vinyl-1,3-diketone (1,2; 23, 24) führen zu 1,4-Diketonen (3 - 10; 25 - 31), die sich zu den 1,3,6-Triketonen (11 - 18; 32 - 38) hydrolysieren lassen. Ein Syntheseweg zu den mono-acetalisierten Vinyl-1,3-diketonen 1, 2; 23, 24 über die Norbornenyl-Gruppierung und nachfolgende Pyrolyse wird angegeben.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130317
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  • 68
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    Einführung der (Dimethylhydrazono)ethylgruppe in methylenaktive Verbindungen und Phenole (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 970-978 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Introduction of the (Dimethylhydrazono)ethyl Group into Methylene Active Compounds and PhenolsIn [2-(dimethylhydrazono)ethyl]trimethylammonium iodide the trimethylammonium group can be substituted by several nucleophiles. With this reagent (dimethylhydrazono)ethyl derivatives of CH-acidic compounds, phenols, and indole can be prepared.
    Notes: In [2-(Dimethylhydrazono)ethyl]trimethylammonium-iodid (19) läßt sich die Trimethylammoniumgruppe durch verschiedenartige Nucleophile verdrängen. CH-acide Verbindungen sowie Phenole und Indole kann man mit diesem Reagenz zu den entsprechenden Hydrazonoethyl-Derivaten umsetzen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130316
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  • 69
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    Synthese neuer Mono- und Disaccharidglycale zum Aufbau von Oligodesoxyoligosacchariden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 955-969 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Novel Mono- and Disaccharide Glycals for the Synthesis of Oligodeoxy OligosaccharidesUnder various conditions opening of the 6-deoxy-allo-epoxide 1 with lithium iodide yields a mixture of the 3-iodo-gluco-(3) and, predominantly, the 2-iodo-altro-hydrine (2), the reaction of which with methyllithium is studied. By a simplified procedure rendering a separation of 2a and 3a unnecessary the preparation of crystalline D-digitoxal (4a) in approximately 50% yield based on 1 is described. The condensation of 1 and 4b in the presence of N-iodosuccinimide yields the α,1→4-linked altro-allo disaccharide derivative 8a, and only minor amounts of the isomeric β,1→4-linked allo-allo disaccharide 10. Following the opening of the epoxide ring in 8a with lithium iodide and subsequent separation of the iodo hydrines by reduction of the bis-altro derivative 11a a synthesis of the methyl glycoside of the terminal disaccharide (12a) in neodigoxin is achieved. Starting with a reduction of 8a to 13b the subsequent opening of the epoxide ring with lithium iodide and separation of the isomers gives an access to the ribo-altro derivative 16b. By its reaction with methyllithium the disaccharide glycal digitoxosyl-digitoxal 15a is synthesized. The linkage of 15b with 1 is effected by application of the N-iodosuccinimide procedure and yields the trisaccharide derivative 17. The structures and conformations of all derivatives are characterized by comprehensive 1H NMR spectroscopy.
    Notes: Die Öffnung des 6-Desoxy-allo-epoxid-Derivats 1 mit Lithiumiodid gibt unter verschiedenen Bedingungen ein Gemisch aus dem 3-Iod-gluco-(3) und überwiegend dem 2-Iod-altro-Hydrin (2), deren Umsetzungen mit Methyllithium untersucht werden. Ein vereinfachtes Verfahren ermöglicht ohne Trennung von 2a und 3a die Herstellung des kristallinen D-Digitoxals (4a) mit ca. 50% Ausbeute, bezogen auf 1. Die Kondensation von 1 mit 4b und N-Iodsuccinimid gibt glatt das α,1→4-verknüpfte altro-allo-Disaccharid-Derivat 8a und nur in geringen Mengen das isomere β,1→4-gebundene allo-allo-Disaccharid 10. Nach Öffnung des Epoxidringes in 8a mit Lithiumiodid und Trennung der Iodhydrine wird durch Reduktion des bis-altro-Derivats 11a das Methylglycosid des terminalen Disaccharids (12a) aus Neodigoxin gewonnen. Durch vorgelagerte Reduktion von 8a zu 13b läßt sich nach Öffnung des Epoxidringes mit Lithiumiodid und Trennung der Isomeren aus dem ribo-altro-Derivat 16b mit Methyllithium das Disaccharidglycal Digitoxosyl-digitoxal 15a darstellen. Die Verknüpfung von 15b mit 1 nach dem N-Iodsuccinimid-Verfahren liefert das Trisaccharid-Derivat 17. Alle Derivate wurden hinsichtlich der Struktur und Konformation durch 1H-NMR-Spektren charakterisiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130315
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    Übergangsmetall-Carbin-Komplexe, LII. (Tricarbonylchrom)-η;6-phenyl als Substituent in Carben- und Carbinkomplexen der VI. Nebengruppe (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1010-1019 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbyne Complexes, LII. (Tricarbonylchromium)-η6-phenyl as Substituent in Carbene- and Carbyne Complexes of the VI. SubgroupThe reaction of tricarbonyl(η6-phenyllithium)chromium with the metalhexacarbonyls of the VI. subgroup and subsequent alkylation by triethyloxonium tetrafluoroborate yields pentacarbonyl-{ethoxy[(tricarbonylchromium)-η6-phenyl]carbene} complexes of chromium, molybdenum, and tungsten (1 - 3). 1 and 3 react with boron trihalides BX3 (X = Cl, Br) by cleavage of the ethoxy group to form trans-tetracarbonylhalogeno[(tricarbonylchromium)-η6-phenylcarbyne]metal complexes 4 - 7. Properties, spectroscopic results, and the X-ray structure analysis of 6 are discussed.
    Notes: Die Umsetzung von Tricarbonyl(η6-phenyllithium)chrom mit den Metallhexacarbonylen der VI. Nebengruppe und anschließende Alkylierung mittels Triethyloxonium-tetrafluoroborat führt zu Pentacarbonyl{ethoxy[(tricarbonylchrom)-η6-phenyl]carben}-Verbindungen des Chroms, Molybdäns und Wolframs (1 - 3). 1 und 3 reagieren mit den Bortrihalogeniden BX3 (X = Cl, Br) unter Abspaltung der Ethoxygruppe zu den trans-Tetracarbonylhalogeno[(tricarbonylchrom)-η6-phenylcarbin]metall-Komplexen 4 - 7. Eigenschaften und spektroskopische Ergebnisse sowie die Röntgenstrukturanalyse von 6 werden diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130320
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    Beiträge zur Chlorierung - Dehydrochlorierung von Perhydro-1,4-thiazepin-5-onen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 995-1009 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chlorination - Dehydrochlorination of Perhydro-1,4-thiazepin-5-onesThe synthesis of unsaturated derivatives of perhydro-1,4-thiazepin-5-ones 3 is investigated. Depending on the substitution the thiazepin-5-ones 3 thereby react with sulfuryl chloride to yield 7- and 2-chloro derivatives 6 and 7; the latter eliminate hydrogen chloride only in the presence of a base (PVP, 8) to give the Δ2-thiazepines 9a,b,d,e,g, whereas the 7-chloro derivatives in situ afford the Δ6-thiazepines 10a - f, the 1,4-thiazepinium chloride 11c being isolated as intermediate. tert-Butyl hypochlorite forms according to the substituent size and solvent polarity 2- and 7-halogenation products, as well as 1,4-thiazepin-5-one-S-oxides 22. Further halogenation of the Δ6-1,4-thiazepines 10a - c results in the formation of unsaturated halogen derivatives 24, 25, and 26.
    Notes: Es wird versucht, ungesättigte Derivate von Perhydro-1,4-thiazepin-5-onen 3 herzustellen. Die Thiazepin-5-one 3 reagieren dabei je nach Substitution mit Sulfurylchlorid zu 7- und 2-Chlorderivaten 6 und 7; letztere eliminieren Chlorwasserstoff erst in Basen-Gegenwart (PVP, 8) zu den Δ2-Thiazepinen 9a,b,d,e,g, die 7-Chlorderivate dagegen in situ zu den Δ6-Thiazepinen 10a - f, wobei das 1,4-Thiazepinium-chlorid 11c in Substanz erhalten wird. tert-Butylhypochlorit ergibt je nach Substituentengröße und Solvenspolarität neben 2- und 7-Halogenierung auch durch Umlagerung 1,4-Thiazepin-5-on-S-oxide 22. Erneute Halogenierung der Δ6-1,4-Thiazepine 10a - c ergibt die ungesättigten Halogenderivate 24, 25 und 26.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130319
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    Zur Kenntnis organischer Lewis-Säuren, 34. Die thermische [4π + 2π]-Cycloaddition von Enolethern an 1,1-dicarbonylsubstituierte Ethene (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1020-1032 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organic Lewis Acids, 341. Thermal [4π + 2π]-Cycloaddition of Enol Ethers to 1,1-Dicarbonyl Substituted EthenesEnol ethers such as ethyl vinyl ether and 1,1-dimethoxyethene (3f) react thermally, in some instances below 0°C, with cyclic 2-alkylidene-1,3-dicarbonyl compounds such as 1 and 2 to give [4π + 2π]-cycloadducts 4 and 5, respectively (cyclic enol acetals and enol orthoesters), and with 1,1-dicyanoethenes 6 to give [2π + 2π]-cycloadducts 7. On passing from toluene to acetonitrile as the solvent, rates of formation of 4bf from 1b and 3f increase about tenfold and those of 7b from 6b and 3f about sixfold. A discussion of these rates, including rates of related reactions, the relative Lewis acid strengths of 1b and 6b, and the behaviour of 1b/3f towards methanol leads to the conclusion that the degree of concert of the formation of 4bf is below 6.5 kJ · mol-1. - The configurations and conformations of adducts 4 and 5 are discussed.
    Notes: Enolether wie Ethylvinylether und 1,1-Dimethoxyethen (3f) bilden mit exocyclisch 1,1-dicarbonylsubstituierten Ethenen wie 1 und 2 z.T. schon unterhalb von 0°C thermisch die [4π + 2π]-Addukte 4 bzw. 5 (cyclische Enolacetale und Enolorthoester) und mit den 1,1-Dicyanethenen 6 die [2π + 2π]-Addukte 7. Die Bildungsgeschwindigkeit von 4bf aus 1b und 3f steigt auf etwa das Zehnfache und die von 7b aus 6b und 3f auf etwa das Sechsfache beim Übergang von Toluol auf Acetonitril als Lösungsmittel. Eine Diskussion dieser Bildungsgeschwindigkeiten unter Einbeziehung verwandter Reaktionsgeschwindigkeiten sowie der relativen Lewis-Säurestärken von 1b und 6b und des Verhaltens des Systems 1b/3f gegenüber Methanol führt zum Schluß, daß der energetische Konzertiertheitsgrad der Bildung von 4bf unter 6.5 kJ · mol-1 liegt. Die Konfigurationen und Konformationen der Addukte 4 und 5 werden diskutiert.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130321
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  • 73
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    Stereochemie aliphatischer Carbokationen, 13. Protonierte Cyclopropane als Zwischenstufen von 1,2-Alkylverschiebungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 129-141 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Aliphatic Carbocations, 13. Protonated Cyclopropanes as Intermediates in 1,2-Alkyl ShiftsThe nitrous acid deamination of 2-ethyl-1-methylbutylamine (10), 1,2-diethylbutylamine (35), and 2-ethyl-1-methylpentylamine (43) has been studied with respect to 1,2-alkyl shifts. Optically active and deuterated amines were employed whenever possible. The structure, configuration, and deuterium distribution of various products (e.g. 16 from 10, 40 and 48 from 35, 56 from 43) are most reasonably explained in terms of alkyl-bridged intermediates (corner-protonated cyclopropanes) which isomerize via proton shifts from corner to corner. The alternative interconversion of open ions via 1,3-H shifts is incompatible with our experimental results.
    Notes: Die Desaminierung von 2-Ethyl-1-methylbutylamin (10), 1,2-Diethylbutylamin (35) und 2-Ethyl-1-methylpentylamin (43) mit salpetriger Säure wurde im Hinblick auf 1,2-Alkylverschiebungen untersucht. Soweit möglich wurden optisch aktive und deuterium-markierte Amine eingesetzt. Die Struktur, Konfiguration und Deuterium-Verteilung verschiedener Produkte (z.B. 16 aus 10, 40 und 48 aus 35, 56 aus 43) wird am besten erklärt mit Hilfe alkylverbrückter Zwischenstufen (eckenprotonierter Cyclopropane), die durch Protonenverschiebung von Ecke zu Ecke isomerisieren. Die alternative Umwandlung offener Kationen durch 1,3-H-Verschiebung ist mit unseren experimentellen Ergebnissen unvereinbar.
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    URL: http://dx.doi.org/10.1002/cber.19801130114
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    Kristall- und Molekülstrukturen des S3N2+-Radikalkations in S3N2+SO3CF3- · 1/2 CH3CN und von S3N2(NSO2F) (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 226-232 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structures of the S3N2+ Radical Cation in S3N2+SO3CF3- · 1/2 CH3CN and of S3N2(NSO2F)The molecular and crystal structures of S3N2+SO3CF3- · 1/2 CH3CN (1) and S3N2NSO2F (2) were determined from single crystal X-ray diffraction data. The S3N2+ radical cation in 1 is planar, two cations being connected through weak S—S bonding interactions to form dimers with a chair configuration. The S3N2 ring of 2, in which the NSO2F group is covalently bonded to one of the S atoms of the S — S group, is not planar; the S — S bond is weaker than in 1.
    Notes: Die Röntgenstrukturanalysen von S3N2+SO3CF3- - 1/2 CH3CN (1) und S3N2NSO2F (2) zeigen in 1 ein planares S3N2+-Radikalkation, wobei zwei Kationen über schwache S-S-Wechselwirkungen zu sesselförmigen Dimeren assoziiert sind. Der an einem S-Atom der S — S-Gruppe substituierte S3N2-Ring in 2 ist nicht planar; die S — S-Bindung ist schwächer als in 1.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130123
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    Kinetische und mechanistische Untersuchungen von Übergangsmetallkomplex-Reaktionen, IV. Reaktionen von Komplexliganden, XVIII. Kinetik und Mechanismus der Einschiebung von 1-(Diethylamino)-1-propin in die Metall-Carbenkohlenstoff-Bindung von Pentacarbonyl(arylmethoxycarben)chrom(O) und -wolfram(O) (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 193-202 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kinetic and Mechanistic Investigations of Transition Metal Complex Reactions, IV. Reactions of Complex Ligands, XVIII. Kinetic and Mechanism of the Insertion of 1-(Diethylamino)-1-propyne into the Metal-Carbene Bond of Pentacarbonyl(arylmethoxycarbene)chromium(0) and -tungsten(0)Pentacarbonyl(arylmethoxycarbene) complexes (CO)5M[C(p-C6H4R)OCH3] (M = Cr, W; R = CF3, Br, H, CH3, OCH3) (1a - g) add 1-(diethylamino)-1-propyne (2) via insertion of the alkyne into the metal-carbene bond. The formation of pentacarbonyl[(diethylamino)(2-aryl-2-methoxy-1-methylethenyl)carbene]chromium(0) and -tungsten(0) (3a - g) in octane follows a second-order rate law: d[3]/dt = k[1][2]. The tungsten complexes react faster than the analogous chromium compounds. Replacement of R = H by electron withdrawing substituents (CF3, Br) results in an increase, by electron donating groups (CH3, OCH3) in a decrease of the reaction rate. The activation enthalpies ΔH≠ are low (25.1 - 39.4 kJ · mol-1), the activation entropies ΔS≠ strongly negative (-129 to -145 J · mol- K-1). The results are discussed on the basis of an associative stepwise mechanism with an attack of the ynamine at the carbene carbon in the first reaction step.
    Notes: Pentacarbonyl(arylmethoxycarben)-Komplexe (CO)5M[C(p-C6H4R)OCH3] (M = Cr, W; R = CF3, Br, H, CH3, OCH3) (1a - g) addieren 1-(Diethylamino)-1-propin (2) unter Einschiebung des Alkins in die Metall-Carbenkohlenstoff-Bindung. Die Bildung von Pentacarbonyl[(diethylamino)(2-aryl-2-methoxy-1-methylethenyl)carben]chrom(0) und -wolfram(0) (3a - g) in Octan erfolgt nach einem Geschwindigkeitsgesetz zweiter Ordnung: d[3]/dt = k[1][2]. Die Wolframkomplexe reagieren schneller als die entsprechenden Chromverbindungen. Ersatz von R = H durch elektronenziehende Substituenten (Br, CF3) führt zu einer Erhöhung, durch elektronenspendende Gruppen (CH3, OCH3) zu einer Verringerung der Reaktionsgeschwindigkeit. Die Aktivierungsenthalpien ΔH≠ sind niedrig (25.1 - 39.4 kJ · mol-1), die Aktivierungsentropien ΔS≠ stark negativ (-129 bis -145 Jmol-1 K-1). Die Ergebnisse werden auf der Grundlage eines mehrstufigen Mechanismus mit einem Angriff des Inamins am Carbenkohlenstoff im ersten Reaktionsschritt diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130120
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    Sugar enolones, XII. Peroxidation of pyranose-derived enol esters: An efficacious synthesis of peracetylhexosuloses and their conversion into γ-pyrones via 3,2-enolones (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 489-510 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zucker-enolone, XII. Peroxidation pyranoider Enolester: Eine ergiebige Synthese von Peracetyl-hexosulosen und ihre Umwandlung in γ-Pyrone über 3,2-EnoloneVon Pyranosen abgeleitete 1,2-Enolacetate des Typs 4 reagieren mit 3-Chlorperbenzoesäure in Ether glatt zu einem Gemisch anomerer Glycos-2-ulose-acetate 6, wie anhand der Umwandlungen 7 → 11/12, 18 → 19/20 und 21 → 22 gezeigt wird. Konstitution und Konfiguration der Produkte stützen sich auf NMR-Daten, auf die Charakterisierung von Hydrierungsprodukten (10 bzw. 23) sowie im Falle von 11, 12 und 22 auf deren Bildung aus den entsprechenden partiell acetylierten Pyranosen 8, 9 und 23 durch RuO4-Oxidation. - Saure Acetylierung überführt die Glycos-2-ulosen in ihre 2,2-Diacetoxy-Derivate (13, 24 bzw. 35) unter Anomerisierung der β-Isomeren; bei vorsichtiger Behandlung mit Acetylchlorid/Pyridin werden dagegen, unter Erhalt der Konfiguration an C-1, die peracetylierten 2,3-Dehydro-pyranosen 15, 17 und 36 erhalten. Unter schwach basischen Bedingungen erfolgt die Ausbildung des γ-Pyron-Systems (42/43) durch doppelte Eliminierung von Essigsäure, wobei die Zwischenprodukte isolierbar sind und als die 3,2-Enolone 37α, 37β und 38 charakterisiert werden können. Hierbei konnte das aus der Tetraacetyl-glucose 44 durch Oxidation leicht darstellbare Triacetyl-endiolon 41, das Zwischenprodukt des Übergangs 11 → 42 sein soll40, als Intermediat ausgeschlossen werden.
    Notes: Pyranose-derived 1,2-enol acetates of type 4 readily react with 3-chloroperbenzoic acid in ether to an anomeric mixture of glycos-2-uloses 6, as is demonstrated by the conversions 7 → 11/12, 18 → 19/20 and 21 → 22. Structural and configurational assignments were based on NMR-data, on the characterization of hydrogenation products (10 and 23), and on the independent formation of 11, 12, and 22 by RuO4-oxidation of the respective partially acetylated pyranoses 8, 9, and 23. -Acid-catalyzed acetylation converts the glycos-2-uloses into their 2,2-diacetoxy derivatives (13, 24, and 35) with anomerization of β-isomers, whereas cautious treatment with acetyl chloride/pyridine affords the peracetylated 2,3-dehydropyranoses 15, 17, and 36 with retention of configuration at C-1. Mildly basic conditions initiate the elaboration of the γ-pyrone systems (42/43) via double elimination of acetic acid, the respective intermediates, 3,2-enolones 37α, 37β, and 38, being readily isolable. The alternate triacetyl-enediolone 41, allegedly40 an intermediate in the conversion 11 → 42 could be excluded as an intermediate on the basis of its synthesis from tetraacetyl-glucose by oxidation and elimination of acetic acid (44 → 45 → 41).
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130208
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    Alkine und Cumulene, XII. Über die Verwendung von Acetylendicarbonsäure-di-tert-butylester in Diels-Alder-Additionen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 531-541 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkynes and Cumulenes, XII. The Application of Di-tert-butyl Acetylenedicarboxylate in Diels-Alder AdditionsDi-tert-butyl acetylenedicarboxylate (1) may be added in good yields to the model dienes 1,3-butadiene (6a), 2-methyl-1,3-butadiene (6b), 2,3-dimethyl-1,3-butadiene (6c), furan (10), and 1,3-cyclohexadiene (19) to afford the Diels-Alder adducts 7a - c, 12 (E = CO2C(CH3)3), and 20, respectively. Under certain conditions the reaction with 10 also leads to the four 2:1-adducts 13 - 16 (E = CO2C(CH3)3). Whereas the esters 7a - c are converted in quantitative yields to the corresponding anhydrides 8a - c by warming in the presence of catalytic amounts of p-toluenesulfonic acid or by heating in substance, the decomposition of 12 and 20 stops at the stage of the monoesters 17 and 21, respectively. Competition experiments show that 1 is approximately three times less reactive towards 6c than dimethyl acetylenedicarboxylate (11). It is shown that 1 is a useful dienophile for the preparation of “mixed” [2.2]paracyclophanes of type 28.
    Notes: Acetylendicarbonsäure-di-tert-butylester (1) reagiert in guten Ausbeuten mit den Modell-Dienen 1,3-Butadien (6a), 2-Methyl-1,3-butadien (6b), 2,3-Dimethyl-1,3-butadien (6c), Furan (10) und 1,3-Cyclohexadien (19) zu den Diels-Alder-Addukten 7a-c, 12 (E = CO2C(CH3)3) und 20. Im Fall von 10 gelingt unter bestimmten Bedingungen auch die Isolierung der vier 2:1-Addukte 13 - 16 (E = CO2C(CH3)3). Während die Ester 7a - c durch Erwärmen in Gegenwart katalytischer Mengen von p-Toluolsulfonsäure bzw. beim Erhitzen in Substanz quantitativ in die entsprechenden Anhydride 8a - c übergeführt werden können, bleibt diese Zersetzung für 12 und 20 auf der Stufe der Monoester 17 bzw. 21 stehen. Wie Konkurrenzexperimente zeigen, ist 1 gegenüber 6c etwa dreimal weniger reaktiv als Acetylendicarbonsäure-dimethylester (11). Es wird gezeigt, daß 1 ein nützliches Dienophil bei der Darstellung „gemischter“ [2.2]Paracyclophane vom Typ 28 ist.
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    Die Spaltung nichtgespannter CC-Einfachbindungen in Tricarbonyleisenkomplexen 5,5-dialkylsubstituierter Cyclopentadiene (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 542-554 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cleavage of Unstrained CC Single Bonds in Tricarbonyliron Complexes of 5,5-Dialkyl-substituted CyclopentadienesCleavage of CC single bonds in η4-spirononadieneiron complex 9 is initiated by Fe2(CO)9 in boiling benzene, leading to the bridged (σ-alkyl-π-cyclopentadienyl)iron complex 10. By Fe2(CO)9 the latter is transformed to the dinuclear “propylfulvene complex” 16. The observed CC bond cleavage reactions of spirocyclopentadienes 6 can also be applied to monocyclic 5,5-dialkylcyclopentadienes 1. Crossover experiments and stereochemical results suggest an intramolecular reaction path and migration of the endo-alkyl group.
    Notes: Die Spaltung einer CC-Einfachbindung im η4-Spirononadieneisen-Komplex 9 wird durch Fe2(CO)9 in siedendem Benzol initiiert und führt zum überbrückten (σ-Alkyl-π-cyclopentadienyl)eisen-Komplex 10. Dieser reagiert - wiederum unter der Einwirkung von Fe2(CO)9 - weiter zum zweikernigen „Propylfulven-Komplex“ 16. Die an Spirocyclopentadienen 6 beobachteten Umwandlungen unter CC-Bindungsspaltung lassen sich auf offenkettige 5,5-Dialkylcyclopentadiene 1 übertragen. Aus Kreuzungsversuchen und stereochemischen Befunden kann ein intramolekularer Reaktionsverlauf unter Wanderung der endo-Alkylgruppe abgeleitet werden.
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    Einfache Synthese von 3-Acetyl-2-norbornanon durch Diels-Alder-Reaktion und Reaktivität seiner Derivate (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 555-565 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Simple Synthesis of 3-Acetyl-2-norbornanone via Diels-Alder Reaction and Reactivity of its DerivativesCyclopentadiene reacts SnCl4-catalyzed with the readily accessible benzyl ether 1b to give norbornene 2. Benzyl cleavage leads to the diol 3, on the other hand hydrogenation yields the 3-acetylnorbornanol 13 which is oxidized and methylated via 6 to 7. The acetyl group of diketone 7 reacts selectively with ylen (→ 8) and orthoformate (→ 9). With methyl lithium however the diol 12 is formed. Selective reaction of the 2-ketogroup of 2 is only possible after protecting the acetyl function in 2 (→ 5 → 14 → 10 → 19). The Grignard reaction of 2 is sterically hindered and leads with methyl or ethyl magnesium halide to 4a or b. The α,β-unsaturated ketones 16 resp. 17a and b are obtained from 4a resp. b via hydrogenation (→ 15a, b), oxidation (→ 11a, b) and dehydration.
    Notes: Cyclopentadien reagiert SnCl4-katalysiert mit dem leicht zugänglichen Benzylether 1b zum Norbornen 2. Benzylspaltung mit Natrium führt zum Diol 3, während Hydrierung das 3-Acetylnorbornanol 13 ergibt, dessen Oxidation und Methylierung über 6 zu 7 führt. Im Diketon 7 reagiert die Acetylgruppe selektiv mit Ylen (→ 8) und Orthoameisensäureester (→ 8), mit Methyllithium wird dagegen das Diol 12 gebildet. Eine selektive Reaktion der 2-Ketogruppe ist nur nach Schützen der Acetylfunktion in 2 (→ 5 → 14 → 10 → 19) möglich. Die Grignard-Reaktion von 2 ist sterisch gehindert. Sie führt mit Methyl- bzw. Ethyl-magnesiumhalogenid zu 4a bzw. b, woraus nach Hydrierung (→ 15a, b), Oxidation → 11a, b), und Wasserabspaltung die α,β-ungesättigten Ketone 16 bzw. 17a und b erhalten werden.
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    URL: http://dx.doi.org/10.1002/cber.19801130213
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    Addition von Aldehyden an aktivierte Doppelbindungen, XXII. Addition von aliphatischen Aldehyden an α,β-ungesättigte Carbonsäureester und Nitrile (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 690-698 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of Aldehydes to Activated Double Bonds, XXII. Addition of Aliphatic Aldehydes to α,β-Unsaturated Esters and NitrilesThiazolium salt catalysed addition of aliphatic aldehydes to α,β-unsaturated esters and nitriles leads to γ-ketocarboxylic esters (1 - 24) and γ-ketonitriles (25 - 32).
    Notes: Aliphatische Aldehyde addieren thiazoliumsalz-katalysiert an α,β-ungesättigte Carbonsäureester und Nitrile unter Bildung von γ-Ketocarbonsäureestern (1 - 24) und γ-Ketosäurenitrilen (25 - 32).
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    URL: http://dx.doi.org/10.1002/cber.19801130226
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    Urofuransäuren - eine bisher unbekannte Klasse von Stoffwechselprodukten (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 699-709 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Urofuranic Acids - a Hitherto Unknown Class of Metabolic CompoundsBy a combination of chromatographic methods 1 mg of pentylurofuranic acid, a dicarboxylic acid C14H20O5, was isolated from 10 1 urine. According to spectroscopic measurements in combination with reactions in microscale its structure is 3-carboxy-4-methyl-5-pentyl-2-furanpropanoic acid (1a). This was confirmed by synthesis. Pentylurofuranic acid does not only occur in urine, but also in blood. Accompanying compounds differ only in the construction of the side chain in position 5.
    Notes: Aus 10 1 Harn wurde durch Kombination verschiedener chromatographischer Verfahren 1 mg Pentylurofuransäure, eine Dicarbonsäure C14H20O5, isoliert. Ihr kommt nach spektroskopischer Untersuchung in Kombination mit Mikroabbaureaktionen die Konstitution 3-Carboxy-4-methyl-5-pentyl-2-furanpropansäure (1a) zu, die durch Synthese gesichert wurde. Die Pentylurofuransäure kommt nicht nur im Harn (0.5-2 mg/24 h), sondern auch im Blut vor. Begleitverbindungen unterscheiden sich von ihr nur durch den Bau der Seitenkette in Stellung 5.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130227
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    Asymmetrische Synthesen, V. Optisch aktive 5-Amino-4-phenyl-1,3-dioxane und deren Einfluß auf die Stereoselektivität der asymmetrischen Strecker-Synthese (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 710-721 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses, V. Optically Active 5-Amino-4-phenyl-1,3-dioxanes and Their Influence on the Stereoselectivity of the Asymmetric Strecker-SynthesisFrom (1S, 2S)-(+)-2-amino-1-phenyl-1,3-propanediol (1) and aldehydes or ketones 2a - e, respectively, the appropriate 5-amino-4-phenyl-1,3-dioxanes 3a - e are prepared. With benzaldehyde they form well crystallizing azomethines 4a - e. The conformation and configuration of 3a - e and 4a - e are deduced spectroscopically. From these results, and from investigations of the epimer equilibria 5a - e/6a - e conclusions are drawn about the stereochemical course of the asymmetric Strecker-synthesis.
    Notes: Aus dem (1S, 2S)-(+)-2-Amino-1-phenyl-1,3-propandiol (1) werden mit den Aldehyden bzw. Ketonen 2a - e die entsprechenden 5-Amino-4-phenyl-1,3-dioxane 3a - e hergestellt, die mit Benzaldehyd die gut kristallisierenden Azomethine 4a - e bilden. Die Konformation und Konfiguration von 3a - e und 4a - e werden spektroskopisch bestimmt. Aus diesen Ergebnissen und den Untersuchungen über das Epimerengleichgewicht 5a - e/6a - e lassen sich Rückschlüsse auf den stereochemischen Verlauf der asymmetrischen Strecker-Synthese ziehen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130228
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    Beiträge zur Chemie des Bors, CV. (N-Lithiomethylamino)dimethylboran als Reagens zur Darstellung N-funktioneller Aminodimethylborane (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 728-738 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, CV. (N-Lithiomethylamino)dimethylborane as a Reagent for the Preparation of N-Functional AminodimethylboranesThe reagent (CH3)2 — N(CH3)Li (1) allows the synthesis of many borylaminoelement compounds such as (CH3)2B — NCH3 — BCH3 — N(CH3)2, (CH3)2Si[NCH3 — B(CH3)2]2, (CH3)2B - NCH3 — Si(CH3)2 — NCH3 — Si(CH3)2Br, (CH3)2B — NCH3 — P(CH3)2 or (CH3)2B — NCH3 — As(CH3)2. Multifunctional element halides cause the formation of a complex mixture of products, and this is in part due to cyclocondensation reactions of longer chain compounds.
    Notes: Das Reagens (CH3)2B — N(CH3)Li (1) ermöglicht die Synthese zahlreicher Borylaminoelement-Verbindungen wie (CH3)2B — NCH3 — BCH3 — N(CH3)2, (CH3)2Si[NCH3 — B(CH3)2]2, (CH3)2B — NCH3 — Si(CH3)2 — NCH3 — Si(CH3)2Br, (CH3)2B — NCH3 — P(CH3)2 oder (CH3)2B — NCH3 — As(CH3)2. Mit mehrfunktionellen Elementhalogeniden wird die Produktpalette komplexer, was auch auf Cyclokondensation der längerkettigen Verbindungen zurückzuführen ist.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130230
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    Neue Kondensationsreaktionen an 4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophen-1,1-dioxid (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 750-756 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Condensation Reactions of 4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophene 1,1-Dioxide4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophene 1,1-dioxide (1) reacts with primary amines according to their basicity to give the compounds 6a - h, and 7, resp.; with hydrazines the monohydrazones (8a - d) are obtained. Condensation with aliphatic diamines leads only in the case of 1,1-ethanediamine to a ring system (2), with the higher homologues to bridged compounds (3a - c). Reaction with methylenediamine dihydrochloride leads to the same product (5) as with ammonia. Active derivatives of carboxylic acids react with 1 to give mono- (9a,b) or bisacylation (10), in the case of thiophosgene the corresponding dioxole 11 is formed. With trialkyl phosphites 1 produces the vinylogue sulfonic esters 12a, b by simple alkylation, analogous to the reaction with diazomethane.
    Notes: 4-Hydroxy-3-oxo-2,5-diphenyl-2,3-dihydrothiophen-1,1-dioxid (1) reagiert mit primären Aminen je nach deren Basizität zu den Verbindungen 6a - h oder 7; mit Hydrazinen erfolgt Monohydrazonbildung zu 8a - d. Kondensation mit aliphatischen Diaminen führt nur im Falle des 1,2-Ethandiamins zum ringgeschlossenen Produkt (2), höhere homologe Diamine bilden verbrückte Verbindungen (3a - c). Die Reaktion mit Methandiamin-dihydrochlorid führt zu Produkt 5, das auch durch Umsetzung mit Ammoniak erhalten wird. Aktive Carbonsäurederivate setzen sich mit 1 zum Mono- (9a, b) bzw. Bisacylprodukt (10) um. Mit Thiophosgen liefert 1 das Dioxol 11; mit Trialkylphosphiten erfolgt Alkylierung zu den vinylogen Sulfonsäureestern 12a, b analog der Umsetzung mit Diazomethan.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130232
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    Bis(pentamethylcyclopentadienyl)germanium und -zinn sowie (Pentamethylcyclopentadienyl)germanium- und -zinn-Kationen: Synthese, Struktur und Bindungsverhältnisse (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 757-769 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bis(pentamethylcyclopentadienyl)germanium and -tin and (Pentamethylcyclopentadienyl)germanium- and -tin Cations: Synthesis, Structure, and Bonding PropertiesSynthesis and properties of bis(pentamethylcyclopentadienyl)germanium (2) and -tin (1) and of the ionic (pentamethylcyclopentadienyl)germanium- and -tin tetrafluoroborates 4 and 3 are described. The structures of 1 - 4 result from spectroscopic and analytical data and in the case of 1 and 3 also from X-ray structure analyses. The bonding in 1 - 4 is discussed on the basis of model MO calculations.
    Notes: Synthese und Eigenschaften des Bis(pentamethylcyclopentadienyl)germaniums (2) und -zinns (1) sowie der ionischen (Pentamethylcyclopentadienyl)germanium- und -zinn-tetrafluoroborate 4 und 3 werden beschrieben. Die Strukturen von 1 - 4 resultieren aus spektroskopischen und analytischen Daten sowie im Falle von 1 und 3 auch aus Röntgenstrukturanalysen. Elektronenstruktur und Bindungsverhältnisse in 1 - 4 werden auf der Basis von MO-Modellrechnungen diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130233
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    Thermolyse von Oxazolin-5-onen, X. 3-Imidazoline und Δ3-Tetrahydropyrimidine durch Thermolyse von 3-Oxazolin-5-onen aus N-Acyldipeptiden (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 770-786 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of Oxazolin-5-ones, X. 3-Imidazolines and Δ3-Tetrahydropyrimidines by Thermolysis of 3-Oxazolin-5-ones Derived from N-Acyl DipeptidesOn thermolysis 2-(acylaminomethyl)-3-oxazolin-5-ones (3a - g) undergo elimination of CO2 to give nitrile ylides which cyclize to 3-imidazolines 4a - g via intramolecular proton transfer. The 2-acylaminoethyl derivative 3h yields a Δ3-tetrahydropyrimidine 5h in an analogous manner. Compounds 3 may be easily obtained from N-acyl dipeptides 1. The temperature dependence of the 1H NMR spectra of 4 is discussed.
    Notes: Die Thermolyse von 2-(Acylaminomethyl)-3-oxazolin-5-onen (3a - g) führt unter Eliminierung von CO2 zu Nitril-yliden, welche nach innermolekularer Protonenübertragung zu 3-Imidazolinen 4a - g cyclisieren. Analog liefert das 2-(Acylaminoethyl)-Derivat 3h ein Δ3-Tetrahydropyrimidin 5h. Die Oxazolinone 3 sind aus N-Acyldipeptiden 1 leicht zugänglich. Die Temperaturabhängigkeit der 1H-NMR-Spektren von 4 wird diskutiert.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130234
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    Stereoselektive Synthesen von Alkoholen, IV. Konformationseinflüsse auf die Stereochemie der Allylsulfoxid-Sulfensäure-allylester-Umlagerung (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 856-863 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselective Synthesis of Alcohols, IV. Conformational Factors Determining the Stereochemistry of the Allyl Sulfoxide/Allyl Sulfenate-RearrangementThe stereochemistry of the [2,3]sigmatropic rearrangement of the conformationally rigid allyl sulfoxides 5 revealed a 6.2 fold preference for axial formation of the new C — O-bond. This preference dominates the 3.1 fold preference for an exo-versus endo-transition state. These data form the basis for a discussion of the stereochemistry of rearrangement of the conformationally flexible allyl sulfoxides 1 and 13.
    Notes: Aus der Stereochemie der [2,3]sigmatropen Umlagerung der konformativ fixierten Allylsulfoxide 5 kann man eine 6.2-fache Präferenz für eine axiale Neuknüpfung der C — O-Bindung ableiten, die über eine 3.1-fache Präferenz für einen exo-Übergangszustand dominiert. Diese Vorstellungen wurden auf die Umlagerung der konformativ flexiblen Allylsulfoxide 1 und 13 übertragen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130307
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    Kumulierte Ylide, VII. Eine Methode zum Aufbau α,β-ungesättigter Carbonsäurederivate (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 912-918 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cumulated Ylides, VII. A Method for the Synthesis of α,β-Unsaturated Carboxylic CompoundsPhosphacumulene ylides 1 add alcohols, thiols, and NH-acidic compounds to form phosphoranes 3, which react with aldehydes to give esters, thiol esters, imidates, thioimidates, amidines, azolides, and sulfonamides of α,β-unsaturated carboxylic acids.
    Notes: Phosphacumulen-Ylide 1 addieren Alkohole, Thiole und NH-acide Verbindungen zu Phosphoranen 3, die sich mit Aldehyden zu Estern, Thiolestern, Imidsäureestern, Imidsäurethioestern, Amidinen, Azoliden sowie Sulfonamiden α,β-ungesättigter Carbonsäuren umsetzen lassen.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130311
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    Mikrobiologische Umwandlung von Steroiden, XVII. Darstellung von unterschiedlichen Mono- und Diketostrukturen von D-Homo-4-pregnen-3,20-dion und D-Homo-1,4-pregnadien-3,20-dion (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 203-220 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbial Transformations of Steroids, XVII. Preparation of Several Mono- and Diketo-structures of D-Homo-4-pregnene-3,20-dione and D-Homo-1,4-pregnadiene-3,20-dione11α- (2) and 15α-monohydroxy- (3), 6β,11α-(4), 11α,15α- (5), 12β,15α- (6), 15α,16α- (7), 7β,11α- (8), 11β,17α- (9), 7β,17α-dihydroxy- (11), and 17α-hydroxy-11-oxo-D-homoprogesterone (10) were prepared by microbiological transformations of D-homoprogesterone (1) with various fungi. The compounds were oxidized by the method of Jones before and after microbiological 1,2-dehydrogenation with Bacillus lentus to the corresponding keto-structures 12 to 17 and 20 respectively 26 to 30. The 14α-hydroxy-11-ketone 18 and 7α,14α-dihydroxy-11-ketone 19 were obtained by microbiological hydroxylation of the 11-ketone 12 with Curvularia lunata. Penicillium lilacinum degraded D-homoprogesterone (1) to D-homotestosterone.
    Notes: Durch mikrobiologische Umwandlung von D-Homoprogesteron (1) mit verschiedenen Pilzstämmen wurden 11α- (2) und 15α-Monohydroxy- (3), 6β,11α- (4), 11α,15α- (5), 12β,15α- (6), 15α,16α- (7), 7β,11α- (8), 11β,17α- (9), 7β,17α-Dihydroxy- (11) und 17α-Hydroxy-11-oxo-D-homo-progesteron (10) hergestellt. Die Verbindungen wurden vor und nach mikrobiologischer 1,2-Dehydrierung mit Bacillus lentus zu den entsprechenden Ketostrukturen 12 - 17 und 20 bzw. 26 - 30 nach Jones oxidiert. Ein 14α-Hydroxy-11-keton 18 und 7α,14α-Dihydroxy-11-keton 19 wurden durch mikrobiologische Zweithydroxylierung des 11-Ketons 12 mit Curvularia lunata erhalten. Penicillium lilacinum baute D-Homoprogesteron (1) zu D-Homotestosteron ab.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19801130121
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    Elektron-Donor-Acceptor-Verbindungen, XIX. Intramolekulare Chinhydrone der [3.3]Metacyclophan-Reihe: syn- und anti-6,9,15,18-Tetramethoxy[3.3]metacyclophane als Vorstufen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 233-240 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XIX. Intramolecular Quinhydrones of the [3.3]Metacyclophane Series: syn- and anti-6,9,15,18-Tetramethoxy[3.3]metacyclophanes as PrecursorsIn the context of the synthesis of [3.3]metacyclophane quinhydrones (e. g, 1 and 2) the stereoisomeric 7,10,17,20-tetramethoxy-2,13-dithia[4.4]metacyclophanes (5/6) were synthesized via 8 - 12. From the disulfones, prepared by oxidation of 5/6, by vacuum gas-phase pyrolysis (570°C/10-4 Torr) two stereoisomeric 6,9,15,18-tetramethoxy[3.3]metacyclophanes were obtained the assignment of which to the syn-constitution 3 and the anti-constitution 4 has been made on the basis of 1H NMR spectra. As experiments on thermal isomerisation show the conformational stability of 3/4 as well as 5/6 is remarkably high. - As side-products of the cyclisation of 11 and 12, and of the sulfone pyrolysis, resp., the compounds 13 - 16 were isolated.
    Notes: Mit dem Ziel der Synthese von Chinhydronen der [3.3]Metacyclophan-Reihe (z. B. 1 und 2) wurden die stereoisomeren 7,10,17,20-Tetramethoxy-2,13-dithia[4.4]metacyclophane (5/6) über die Vorstufen 8 - 12 synthetisiert. Aus den durch Oxidation von 5/6 erhaltenen Disulfonen entstanden durch Gasphasen-Vakuum-Pyrolyse (570°C/10-4 Torr) zwei stereoisomere 6,9,15,18-Tetramethoxy[3.3]metacyclophane, deren Zuordnung zur syn-Konstitution 3 und anti-Konstitution 4 aufgrund der 1H-NMR-Spektren getroffen wurde. Wie Versuche zur thermischen Isomerisierung zeigen, ist die konformative Stabilität von 3/4 wie auch von 5/6 bemerkenswert groß. - Als Nebenprodukte der Cyclisierung von 11 und 12 bzw. der Sulfon-Pyrolyse wurden die Verbindungen 13 - 16 isoliert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130124
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    Elektron-Donor-Acceptor-Verbindungen, XX. Intramolekulare Chinhydrone der [3.3]Metacyclophan-Reihe: Synthese, Struktur, Stabilität und Charge-Transfer-Absorptionen von stereoisomeren [3.3]Metacyclophan-Chinhydronen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 241-254 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XX. Intramolecular Quinhydrones of the [3.3]Metacyclophane Series: Synthesis, Stability, and Charge Transfer Absorptions of Stereoisomeric [3.3]Metacyclophane QuinhydronesOn the attempt to synthesize the syn- and anti-[3.3]metacyclophane quinhydrones 1 and 2 by demethylation of 3 and 4, resp., and subsequent oxidation the same [3.3](2,6)-p-benzoquinonophane (5) was obtained which on catalytic hydrogenation yielded syn-[3.3]metacyclophane quinhydrone 1. Partial demethylation, however, and following oxidation led from 3 to the dimethyl ether 7 of the syn-quinhydrone 1, and analogously from 4 to the dimethyl ether 8 of anti-[3.3]-metacyclophane quinhydrone 2. The structural assignment of the stereoisomers was confirmed by an X-ray structure analysis of 7. In addition to 7 and 8, the corresponding monomethyl ethers 10 and 12 were obtained. - The anti-[3.3]metacyclophanes 8 and 12 undergo a complete thermal rearrangement to the syn-isomers 7 and 11, resp., from which a stronger ground state stabilisation by charge transfer interaction is concluded for the donor-acceptor systems of the syn-series. - The quinhydrones 7, 8, 10, 11, and 12 show broad, intensive charge transfer absorptions in the range from 300 to 550 nm which for the pairs of stereoisomers 7/8 and 11/12, in spite of the very different donor-acceptor orientation, are surprisingly similar: the absorption intensity of the CT band, however, is considerably stronger for the anti-quinhydrones than for their syn-isomers.
    Notes: Bei Versuchen zur Darstellung der syn- und anti-[3.3]Metacyclophan-Chinhydrone 1 und 2 wurde durch Demethylierung von 3 bzw. 4 und anschließende Oxidation dasselbe [3.3](2,6)-p-Benzochinonophan (5) erhalten, das durch katalytische Hydrierung syn-[3.3]Metacyclophan-Chinhydron 1 ergab. Partielle Demethylierung und anschließende Oxidation führten jedoch ausgehend von 3 zum Dimethylether 7 des syn-Chinhydrons 1 und entsprechend aus 4 zum Dimethylether 8 des anti-[3.3]Metacyclophan-Chinhydrons 2. Die Strukturzuordnung der Stereoisomeren wurde durch Röntgen-Strukturanalyse von 7 bestätigt. Neben 7 und 8 wurden die entsprechenden Monomethylether 10 und 12 erhalten. - Die anti-Verbindungen 8 und 12 lagern sich thermisch quantitativ in die syn-Isomeren 7 bzw. 11 um, woraus auf eine stärkere Grundzustands-Stabilisierung durch Charge-Transfer-Wechselwirkung bei den Donor-Acceptor-Systemen der syn-Reihe geschlossen wird. - Die Chinhydrone 7, 8, 10, 11 und 12 zeigen breite, intensive Charge-Transfer-Absorptionen im Bereich von 300 - 550 nm, die bei den Stereoisomeren-Paaren 7/8 und 11/12 trotz der sehr unterschiedlichen Donor-Acceptor-Orientierung überraschend ähnlich sind; die Absorptionsintensität der CT-Bande ist jedoch bei den anti-Chinhydronen beträchtlich größer als bei den syn-Isomeren.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130125
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    Fluorenylsilane, I. Darstellung und Strukturuntersuchung von Fluorenylsilanen mit funktionellen Gruppen am Silicium (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 278-288 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fluorenylsilanes, I. Preparation and Structural Investigations of Fluorenylsilanes with Functional Groups at SiliconChloro-9-fluorenyldiphenylsilane (3a) and 9-fluorenyltris(trimethylsilyl)silane (3b) have been prepared by the reaction of the corresponding halosilanes with 9-fluorenyl lithium. The chloro substituent in 3a can be exchanged for other functional groups. With alkaline conditions cleavage of the fluorenyl-silicon bond may happen. The molecular structures of 3b and 9-fluorenyldiphenylsilanole (6a) have been determined by X-ray diffraction. In both compounds the substituents at the Cfluorenyl—Si bond are exactly staggered. The fluorenyl group in 3b is slightly folded, the Cfluorenyl—Si bond is lengthened to 194.7 (4) pm.
    Notes: Chlor-9-fluorenyldiphenylsilan (3a) und 9-Fluorenyltris(trimethylsilyl)silan (3b) wurden durch Umsetzung der entsprechenden Halogensilane mit 9-Fluorenyllithium dargestellt. Der Chlorsubstituent in 3a läßt sich gegen andere funktionelle Gruppen austauschen; im alkalischen Medium kann daneben die Fluoren-Silicium-Bindung gespalten werden. Von 3b und 9-Fluorenyldiphenylsilanol (6a) wurden Röntgenstrukturanalysen durchgeführt. In beiden Verbindungen stehen die Substituenten bezüglich der CFluorenyl— Si-Bindung streng gestaffelt. Der Fluorenyl-Rest in 3b ist leicht gefaltet, die CFluorenyl—Si-Bindung auf 194.7 (4) pm aufgeweitet.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19801130130
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    Die Oxidation von Hexathioethanen zu Tetrathioethen-Radikalkationen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 289-301 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Oxidation of Hexathioethanes to Tetrathioethene Radical CationsThe oxidation of hexakis(alkylthio)ethanes (RS)3C — C(SR)3 by AlCl3/H2CCl2, NOBF4, or I2 yields tetrakis(alkylthio)ethene radical cations (RS)2Ċ=⊕C(SR)2. The dark violet tetrahydrotetrathiafulvalenium triiodide 1 · I3 (n = 2) has been obtained as a crystalline solid. Other derivatives such as the dibenzotetrathiafulvalene (2) and the quinodimethane (4) radical cations have been characterized by ESR spectroscopy in solution: The coupling constants and the g values reveal that the spin density accumulates preferentially at the S centers. The alkyl proton coupling is rationalized advantageously by angle-independent spin polarization. For tetrathiafulvalene, geometry-optimized MNDO calculations predict a lengthening of the central C = C bond on oxidation and the positive charge centered predominantly at sulfur.
    Notes: Die Oxidation von Hexakis(alkylthio)ethanen (RS)3C — C(SR)3 mit AlCl3/H2CCl2, NOBF4 oder I2 führt zu Tetrakis(alkylthio)ethen-Radikalionen (RS)2Ċ=⊕C(SR)2. Das schwarzviolette Tetrahydrotetrathiafulvalenium-triiodid 1 · I3 (n = 2) konnte in Substanz isoliert werden. Weitere Derivate wie das Dibenzotetrathiafulvalen- (2) und das Chinodimethan-(4)-Radikalion werden in Lösung ESR-spektroskopisch charakterisiert: Aus den Kopplungskonstanten und g-Faktoren folgt, daß sich die Spindichte überwiegend an den S-Zentren befindet. Die Alkylprotonen-Kopplungen lassen sich vorteilhaft mit winkelunabhängiger Spinpolarisation beschreiben. Für Tetrathiafulvalen ergeben geometrieoptimierte open-shell-MNDO-Berechnungen, daß sich die zentrale C = C-Bindung bei Oxidation verlängern, und daß die positive Ladung überwiegend am Schwefel zentriert sein sollte.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130131
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  • 94
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    Trimethylsilylcyanid als Umpolungsreagens, IV. Substituenteneffekte am acylierenden Nucleophil zur Steuerung der 1,2-/1,4-Addition an α,β-ungesättigte Ketone (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 324-332 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trimethylsilyl Cyanide - A Reagent for Umpolung, IV. Substituent Effects in the Acylating Nucleophile for Directing 1,2-/1,4-Addition to α,β-Unsaturated KetonesMesityl oxide (6) is attacked by nucleophilic anions 5a - f in DME at the C-1 and/or C-3 position. Depending on the p-substituent in 5 the whole scale from 100% 1,2-adduct 7 (with 5a, X = N(CH3)2) to 100% 1,4-adduct 9 (with 5f, X = CN) is covered. In ether the amount of 9 is strongly enhanced. The control of regiospecificity has to be ascribed to differing “hardness” of 5a - f, since possible ion pairing produces opposite effects. The oxidation potentials of 5 and the reduction potential of 6 in DME exclude electron transfer before 1,4-addition. The easily reducible dienone 14, however, reacts with 5c via radicals.
    Notes: Die nucleophilen Anionen 5a - f greifen Mesityloxid (6) in DME in C-1- und/oder C-3-Position an, wobei in Abhängigkeit vom p-Substituenten in 5 die gesamte Skala von 100% 1,2-Addukt 7 (mit 5a, X = N(CH3)2) zu 100% 1,4-Addukt 9 (mit 5f, X = CN) durchlaufen wird. In Ether erhöht sich der Anteil an 9 erheblich. Die Steuerung muß der unterschiedlichen „Härte“ von 5a - f zugeschrieben werden, da eine mögliche Ionenpaarbildung gegenläufig wirkt. Die Oxidationspotentiale von 5 und das Reduktionspotential von 6 schließen in DME eine vorgelagerte Elektronenübertragung bei 1,4-Addition aus, während das leicht reduzierbare Dienon 14 mit 5c radikalisch reagiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130133
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  • 95
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    Kernresonanzspektroskopische Untersuchungen an Bor-Verbindungen, XVII. 17O-NMR-Studien an Organyloxyboranen, Organyloxydiboranen(4), Dioxaborolanen und Boroxinen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 333-341 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR Studies of Boron Compounds, XVII. 17O NMR Studies on Organyloxyboranes, Organyloxydiboranes(4), Dioxaborolanes, and Boroxins17O chemical shifts of 30 boron-oxygen compounds containing tricoordinate boron atoms can be interpreted in terms of B - O(pp)π interaction. In consonance with other physical data a decrease in the π bond order is indicated by the δ17O data along the series (R2B)2O 〉 (RBO)3 〉 R2BOR 〉 RB(OR)2 〉 B(OR)3 (R either CH3 or C2H5). Natural abundance 17O NMR spectra are recorded by PFT NMR spectroscopy in relatively short time as “routine” measurements.
    Notes: Die 17O-chemischen Verschiebungen von 30 Bor-Sauerstoff-Verbindungen, die dreifach koordiniertes Bor enthalten, sind mit B - O(pp)π-Wechselwirkung zu interpretieren. In Übereinstimmung mit anderen physikalischen Daten legen die δ17O-Werte eine Abnahme der π-Bindungsordnung in der Reihe (R2B)2O 〉 (RBO)3 〉 R2BOR 〉 RB(OR)2 〉 B(OR)3 (R = CH3 oder C2H5) nahe. 17O-NMR-Spektren von Verbindungen mit natürlicher Isotopenhäufigkeit werden mittels PFT-NMR-Spektroskopie relativ rasch in „Routinemessungen“ erhalten.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130134
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  • 96
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    Synthese von Spirocyclohexadienonen und deren unerwartete Umlagerung zu tricyclischen Verbindungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 669-675 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Spirocyclohexadienones and their Rearrangement to Tricyclic Compounds(4-Hydroxyphenyl)acetic acid reacts with diisopropyl- and dicyclohexylcarbodiimide to yield the spirocyclohexadienones 1 and 2. When treated with BF3-etherate, these compounds rearrange to give 3 and 4. The structure of 3, concluded from the NMR-spectra, was confirmed by rearranging the corresponding deuterium-labeled dienone 1a and determining the position of deuterium in the rearranged compound 3a.
    Notes: (4-Hydroxyphenyl)essigsäure reagiert mit Diisopropyl- und Dicyclohexylcarbodiimid zu den Spirocyclohexadienonen 1 und 2. Diese Verbindungen lagern sich mit BF3-Etherat zu den Verbindungen 3 und 4 um. Die aufgrund der Kernresonanzspektren postulierte Konstitution der Verbindung 3 wurde bestätigt, indem das entsprechende deuteriummarkierte Dienon 1a umgelagert und die Position des Deuteriums im Umlagerungsprodukt 3a aus den Kernresonanzspektren bestimmt wurde.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130224
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  • 97
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    Cholestano-cobaloxime und Cholestano-rhodoxime. Synthese, Charakterisierung und Umlagerung von Modellverbindungen für die Aktivstelle von Methylmalonyl-CoA-Mutase (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 650-668 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparative, Spectroscopic, and Crystallographic Investigations on Phosphinato Complexes of Rhenium with Bidentate Nitrogen LigandsCholestano-cobaloximes and cholestano-rhodoximes, three diastereoisomers of each constitution, were synthesised from cholestane-2,3-dione dioxime (3). The diastereoisomeric complexes were separated and characterised by their spectra. One of the axial ligands was invariably pyridine, the other either chlor (9), methyl (10), 2,2-bis(methoxycarbonyl)propyl (11), 2,2-bis(benzyl-oxycarbonyl)propyl (12), or 2,2-bis(2-naphthylmethoxycarbonyl)propyl (13 and 14). Irradiation of the complexes 11, 12, 13, and 14 in ethanol or 2-propanol afforded, apart from dimethylmalonic diester, other products among which was the corresponding methylsuccinic diester in yields of approx. 1, 20, 23, and 13%, respectively. The methylsuccinic acid bis(2-naphthylmethyl ester) obtained from the irradiation of the diastereoisomeric cholestano-cobaloximes 13a, b and c was found to be practically racemic.
    Notes: Aus Cholestan-2,3-dion-dioxim (3) wurden jeweils drei diastereomere Cholestano-cobaloxime und Cholestano-rhodoxime synthetisiert, die getrennt und spektroskopisch charakterisiert wurden. Pyridin diente durchweg als einer der axialen Liganden, der andere war Chlor (9), Methyl (10), 2,2-Bis(methoxycarbonyl)propyl (11), 2,2-Bis(benzyloxycarbonyl)propyl (12) oder 2,2-Bis(2-naphthylmethoxycarbonyl)propyl (13 und 14). Bestrahlung der Komplexe 11, 12, 13 und 14 in Ethanol oder 2-Propanol gab neben den Dimethylmalonsäureestern und weiteren Produkten auch die entsprechenden Methylbernsteinsäure-diester in Ausbeuten von etwa 1, 20, 23 und 13%. Der aus den diastereomeren Cholestano-cobaloximen 13a, b und c erhaltene Methylbernsteinsäure-bis(2-naphthylmethylester) war praktisch racemisch.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130223
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  • 98
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    Gespannte Anthrachinonophane und Anthracenophane (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 676-689 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Strained Anthraquinonophanes and AnthracenophanesThe clamped anthraquinonophane 3 and anthracenophanes 4, 5 have been synthesized. Their spectroscopic properties are compared with those of the open chained compounds 8 and 10 and the corresponding phanes (12a - 15a and 16 - 18) with longer bridges. The clamping causes significant hypsochromic shifts in the UV spectra and distinct shifts in the 1H-/13C-NMR-spectra. Reaction of the anthraquinonophane 3 with an excess of methyllithium selectively yields the exocyclic methyl-substituted anthracenophane 5.
    Notes: Die verklammerten Anthrachinonophane 3 und Anthracenophane 4, 5 wurden erstmals synthetisiert und ihre spektroskopischen Eigenschaften mit denen offenkettiger (8 und 10) und mit längeren Brücken überspannter (12a - 15a und 16 - 18) Anthrachinone und Anthracene verglichen. Die Verklammerung bedingt signifikante hypsochrome Verschiebungen im UV-Spektrum sowie deutliche Verschiebungen einzelner Signale in den 1H-/13C-NMR-Spektren. Umsetzung des Anthrachinonophans 3 mit überschüssigem Methyllithium führt selektiv zu der exocyclisch methylsubstituierten Anthracenverbindung 5.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130225
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    Asymmetrische Synthesen, VI. Synthese optisch aktiver Aziridine (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 722-727 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses, VI. Synthesis of Optically Active AziridinesThe optically active tetrahydro-1,4-oxazine derivatives 1a - e are converted via their respective tosylates 2a - e to the optically active aziridine derivatives 3a - e. The constitution and configuration of 3a - e are ascertained spectroscopically. The nitrogen inversion is investigated by low and high temperature 1H-NMR spectroscopy.
    Notes: Die optisch aktiven Tetrahydro-1,4-oxazin-Derivate 1a - e werden über die entsprechenden Tosylate 2a - e in die optisch aktiven Aziridin-Derivate 3a - e übergeführt. Die Konstitution und Konfiguration von 3a - e werden spektroskopisch ermittelt. Durch 1H-NMR-spektroskopische Tief-und Hochtemperaturmessungen wird die Inversion am Stickstoff untersucht.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130229
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  • 100
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    Sterisch gehinderte Olefine, V. Synthese und Röntgenstrukturanalyse von trans-1-Ethyl-2-(1-ethyl-2-adamantyliden)adamantan, einem hochgespannten Ethylen. Vergleich mit Kraftfeld-Rechnungen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 739-749 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sterically Hindered Olefins, V. Synthesis and X-Ray Structure Analysis of trans-1-Ethyl-2-(1-ethyl-2-adamantylidene)-adamantane, a Highly Hindered Ethylene. Comparison with Force-Field CalculationsSynthesis of trans-1-ethyl-2-(1-ethyl-2-adamantylidene)adamantane (2) starting from 1-ethyl-2-adamantanone (1) is described. The structure of 2 was determined by X-ray structure analysis (2(C2) symmetry). Steric hindrance results in a torsion and an out-of-plane deformation of the CC double bond, and also is evident by characteristic elongations of bond lengths and by bond angle deformations. The CC double bond, e.g., is elongated to 1.358 Å, the vinylic bonds with a quaternary carbon atom are elongated to 1.563 Å. The strongest bond angle deformation occurs at the substituted sp3-hybridized C-atoms in the allylic positions increasing one angle to 122.1°. The geometry of 2 is compared with the parent compound adamantylideneadamantane (3). Calculations using Allinger's force-field show for 2 and 3 a sufficient agreement with the experimentally determined structure parameters and an increased strain energy by 28.1 kcal mol--1. The force-field calculations have been extended to the analogous adamantylideneadamantanes 4 - 7.
    Notes: Es wird die Synthese von trans-1-Ethyl-2-(1-ethyl-2-adamantyliden)adamantan (2) aus 1-Ethyl-2-adamantanon (1) beschrieben. Die Struktur von 2 wurde durch Röntgenstrukturanalyse bestimmt (2(C2)-Symmetrie). Die starke sterische Spannung in 2 äußert sich in einer Torsion um die C = C-Doppelbindung bei einer gleichzeitigen pyramidalen Verzerrung der Konfiguration ihrer C-Atome, sowie in charakteristischen Bindungsaufweitungen und Winkeldeformationen. Die C = C-Doppelbindung verlängert z.B. auf 1.358 Å; die vinylständigen C — C-Einfachbindungen mit einem quartären Kohlenstoff verlängern auf 1.563 Å. Die stärkste Winkeldeformation erfolgt an den substituierten, allylständigen sp3-hybridisierten C-Atomen (Vergrößerung eines Winkels auf 122.1°). Die Geometrie von 2 wird mit dem weniger gespannten, unsubstituierten Adamantylidenadamantan (3) verglichen. Kraftfeld-Rechnungen nach Allinger für 2 und 3 ergeben eine hinreichend gute Übereinstimmung mit den experimentell ermittelten Strukturparametern und eine um 28.1 kcal/mol höhere Spannungsenergie für 2. Die Kraftfeld-Rechnungen wurden auf analoge Adamantylidenadamantan-Derivate (4 - 7) ausgedehnt.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130231
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