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  • 1985-1989
  • 1975-1979  (849)
  • 1870-1879
  • 1977  (849)
  • Inorganic Chemistry  (816)
  • pharmacokinetics
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 137-145 
    ISSN: 1432-1041
    Keywords: Chlormethiazole ; pharmacokinetics ; metabolites ; oral administration ; young and elderly human subjects ; quantitative gas chromatographymass spectrometry ; whole blood distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma concentration of chlormethiazole and two of its metabolites has been measured in three young and three aged human subjects following administration of a single oral dose of chlormethiazole. A sensitive analytical method based on gas chromatography-mass spectrometry using the selective ion monitoring mode of operation was developed to permit quantitation of the plasma levels. The time course of the plasma concentration of chlormethiazole and metabolites showed wide inter-subject variation, particularly between the young and elderly subjects. Absorption of chlormethiazole was rapid in the subjects of both groups as assessed by the time taken to reach the peak plasma concentration. The mean peak plasma level of chlormethiazole was more than five times greater in the elderly (2.90±1.56 µg/ml) than in the young (0.55±0.58 µg/ml) subjects. The plasma level of chlormethiazole was consistently higher in the aged subjects and this was reflected by the larger area under the plasma curve in aged (7.62±5.37 µg.h/ml) than in young (0.94±0.66 µg.h/ml) individuals. Decreased pre-systemic elimination by the liver has been suggested as an important factor contributing to the higher plasma level in the elderly. Estimates of absolute systemic availability, calculated by reference to previous intravenous studies, were greater for the elderly subjects. The distribution of chlormethiazole in whole blood from six young and six elderly human subjects was investigated in vitro. The unbound fraction of chlormethiazole in plasma increased significantly from 0.308±0.035 in young subjects to 0.403±0.067 in the elderly. Distribution of the drug in whole blood was different for the two age groups; the fraction of drug distributed to plasma water was significantly greater and the fraction in blood cells was significantly less in the aged.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 171-174 
    ISSN: 1432-1041
    Keywords: Tolamolol ; hypertension ; pharmacokinetics ; mean steady-state concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Tolamolol was administered in a “double-blind” study to fifteen hypertensive patients by dose-titration against arterial blood pressure. Mean steady-state plasma tolamolol concentrations (Css) were determined for each patient from the area under the plasma concentration — time curve during a dosage interval whilst patients were receiving optimal tolamolol doses. No significant correlation was observed between daily tolamolol dose and Css; the relationship between fall in lying mean arterial pressure and Css also failed to reach conventional levels of statistical significance, but Css was observed to be correlated with the fall in standing pressure. The results suggest that plasma concentrations in excess of 200 ng/ml may be required to achieve an effective hypotensive response with the drug.
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  • 3
    ISSN: 1432-1041
    Keywords: Muzolimine ; pharmacodynamics ; pharmacokinetics ; furosemide ; saluresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In a biometrically planned, double-blind study on 12 Oedema-free male patients the saluretic effect of muzolimine 30 mg was compared with furosemide 40 mg. The plasma level of muzolimine was determined and correlated with its pharmacodynamics. In terms of excretion during the 12-hour observation period muzolimine 30 mg had as great a cumulative effect as furosemide 40 mg. There was a significant difference in the time-response curve. During the first two hours furosemide 40 mg had more saluretic effect than muzolimine 30 mg. Between two and four hours there was no significant difference between the two substances. Between four and six hours, however, muzolimine was somewhat more effective than furosemide, although the difference did not reach the level of significance. After 6 h there was no longer any difference between the two compounds. The half-life of the fall in concentration of muzolimine in plasma was 3.7 up to 10 h after its administration. The time-response curve of the increased urine excretion correlated well with the time course of the concentration of muzolimine in plasma.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 125-132 
    ISSN: 1432-1041
    Keywords: Valproic acid ; pharmacokinetics ; saliva concentration ; urinary excretion ; serum protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of valproic acid (VPA) have been studied in 6 healthy subjects following a single 600 mg dose, and after multiple doses over 12 days (1200 mg daily) of enteric-coated sodium valproate. A time lag before absorption of 1 to 2 h was observed in each subject, and then absorption was rapid, peak concentrations being recorded 3 to 4 h after administration of the dose. The plasma level decline was biphasic with a terminal half-life of 15.9±2.6 h in the single dose and 17.3±3.0 h in the multiple dose experiments. There was no evidence of dose dependent kinetics or autoinduction. Total plasma clearance was 0.0064±0.0011 l/kg×h. The apparent volume of distribution was small at 0.15±0.2 l/kg. The mean steady state plasma concentration (Css) reached after 4 days was 81.3±13.0 µg/ml. Css observed was lower than Css predicted (99.2±14.7 µg/ml) from single dose kinetics (p〈0.001). The difference was probably due to a reduction in plasma protein binding at higher concentrations. VPA concentration in saliva was between 0.4 and 4.5% of the total plasma concentration and was not equal to the concentration of unbound drug in plasma (6.7±0.8% unbound). 3.2% of the dose was excreted in urine as the parent drug and 21.2% as conjugated metabolites.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 367-373 
    ISSN: 1432-1041
    Keywords: Sulphamethizole ; tetracycline ; doxycycline ; rest ; exercise ; pharmacokinetics ; excretion ; absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The serum level and urinary excretion of sulphamethizole, tetracycline and doxycycline were studied in healthy volunteers subjected to intensive exercise and bed rest in a cross-over trial. Each group consisted of 7–8 subjects. The exercise or bed rest began 15 min before oral administration of the drug and was continued for the following 4 hours. During exercise serum drug concentration and the area under the serum concentration-time curve for each agent was significantly higher (p〈0.05) than the corresponding values at rest. Exercise greatly suppressed the renal excretion of tetracycline and doxycycline, but the decrease alone appeared insufficient to account for the pronounced increase in serum drug concentration. Total drug excretion in urine was unchanged. Thus, it seemed most unlikely that overall absorption from the gastrointestinal tract had been altered by exercise. However, the rate of absorption appeared to be more rapid in the exercise than in the rest period. Marked haemoconcentration was not produced by the exercise. In addition to changes in absorption and elimination rates, alteration in the volume of distribution might contribute to the higher serum drug concentration during exercise. Therefore, the level of physical activity should be considered in the interpretation of pharmacokinetic data both in clinical practice and in pharmacokinetic studies.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 11 (1977), S. 149-154 
    ISSN: 1432-1041
    Keywords: Hydroflumethiazide ; spectrofluorometry ; pharmacokinetics ; plasma half life ; renal excretion ; renal disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A spectrofluorometric method for determination of hydroflumethiazide in human plasma and urine has been developed. The limit of detection was 10 ng/ml plasma and 100 ng/ml urine. The plasma concentration of hydroflumethiazide was determined for 9–11 hours and excretion in urine for 24–37 hrs after oral administration of about 1 mg/kg body weight to 7 subjects. Plasma half life in healthy subjects was 1.9–2.1 h, and 2.7–8.6 h in patients during the period 4–9 hrs after dosing. Cumulative excretion in urine was 67–79% of the dose during 31–37 hrs in 6 subjects; one patient with renal disease was found to excrete only 25.8% of dose during 24 hours. Renal clearance of hydroflumethiazide was higher in the healthy subjects (0.29–0.44 1 h−1 kg−1) than in the patients (0.040–0.15 l h−1 kg−1). Plasma half life of hydroflumethiazide was not closely correlated with renal clearance of the drug, which suggests that other factors may play a role in determining plasma half life.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 355-357 
    ISSN: 1432-1041
    Keywords: Nitrazepam ; placental transfer ; pharmacokinetics ; plasma levels ; protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Six women from 14 to 17 weeks pregnant, and 12 woman from 36 to 40 weeks pregnant, were given nitrazepam 5 mg orally about 12 h before legal abortion by hysterotomy in the former group and elective caesarean section in the latter group. The concentration of nitrazepam was determined by gas-liquid chromatography. Binding to plasma proteins was evaluated by separation of the protein-free fraction by ultracentrifugation. In the first group (early pregnancy) the level of nitrazepam was found to be lower in the fetal than in the maternal circulation. The concentration in amniotic fluid was still lower. In the latter group (late pregnancy) the concentration both of unbound and total nitrazepam in maternal and fetal plasma were in equilibrium, which indicated an increase in transplacental transfer in late pregnancy. The percentage of unbound nitrazepam in both cases was 12%.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 383-386 
    ISSN: 1432-1041
    Keywords: Benzodiazepine ; temazepam ; pharmacokinetics ; bioavailability ; hard and soft gelatine capsules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma levels of temazepam were determined in healthy subjects after single oral administration of soft and hard gelatin capsules, and after 7 consecutive night-time doses in soft capsules. Absorption from soft gelatin capsules was significantly faster and produced earlier and higher peak plasma levels. The two pharmaceutical forms did not show any significant difference in relative availability. The apparent half-life of temazepam after night-time administration was significantly shorter than after morning administration, but no change in half-life was observed between the first and seventh night-time doses.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 387-392 
    ISSN: 1432-1041
    Keywords: Digoxin ; β-methyldigoxin ; prolonged administration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Five healthy volunteers received digoxin 0.4 mg or β-methyldigoxin 0.4 mg i. v., daily for 14 days, in a randomized cross-over arrangement. By monitoring minimal plasma concentrations during multiple dosing, it was found that the steady state pharmacokinetics of digoxin and β-methyldigoxin could be estimated even better by a one-compartment than by a two-compartment model. The following mean parameters were calculated: the half life of digoxin of 1.54±0.31 days was significantly shorter than the half life of 2.29±0.34 days for β-methyldigoxin. The distribution volume of 807±187 liters for digoxin was not significantly larger than the 735±227 liters for β-methyldigoxin. Renal digoxin clearance of 191±25 ml/min was significantly higher than both the renal clearance of β-methyldigoxin of 111±23 ml/min and also the creatinine clearance, which indicates tubular secretion of digoxin. There was a 2.8-fold accumulation of β-methyldigoxin injected once a day, which was significantly higher than the 1.8-fold accumulation of digoxin.
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  • 10
    Electronic Resource
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    Springer
    European journal of clinical pharmacology 12 (1977), S. 451-456 
    ISSN: 1432-1041
    Keywords: Bioavailability ; carbamazepine ; elimination ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The time-courses of plasma carbamazepine concentrations were followed in six apparently healthy adult subjects who, at different times, took single oral drug doses of 200, 400, 500, 600, 700, 800 and 900 mg. There were some suggestions of impaired bioavailability of the drug when given in tablet form. The following values were obtained for various pharmacokinetic parameters:k abs =0.176±0.209 h−1;k=0.0203±0.0055 h−1; T1/2=37.5±13.1 h; VD=0.825±0.1041 · kg−1; Clearance=0.0163±0.0061 l · kg−1. The elimination rate constant showed a statistically significant increase with increasing drug dose. This may help explain the clinical observation that the rate of rise of steady state plasma carbamazepine concentrations tends to decrease with dose increase in patients taking carbamazepine alone.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 11 (1977), S. 19-25 
    ISSN: 1432-1041
    Keywords: Diabetes mellitus ; sulfonylurea ; glibenclamide ; pharmacokinetics ; repeated administration ; deep compartment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Six maturity onset diabetic patients took glibenclamide 5 mg by mouth, every morning 10 min before a standard breakfast. Serum levels of immunoreactive glibenclamide, glucose and immunoreactive insulin were measured repeatedly on the first and 15th days of treatment. Measured glibenclamide blood levels were in close agreement with an analogue computer simulation of data obtained from healthy volunteers: there was no accumulation of drug in the blood, but there was strong evidence for the existence of a slowly equilibrating “deep” compartment. Considerable insulin release and correction of the breakfast-induced hyperglycaemia were observed immediately after administration of the drug, as well as 5 h later, at lunch time. The clinical significance of blood levels of glibenclamide, as well as the correlation of pharmacokinetics with pharmacodynamics, are discussed in the light of these results.
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  • 12
    Electronic Resource
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    Springer
    European journal of clinical pharmacology 11 (1977), S. 57-64 
    ISSN: 1432-1041
    Keywords: General equation ; pharmacokinetics ; first pass effect ; extra-hepatic drug elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary A general expression for the ratio of areas below the blood concentration-time curves after intravenous and oral drug administration is derived. This derivation does not require the assumption of a specific compartmental model to describe drug distribution within the body. Similarly an expression for the amount of drug metabolised in the liver is derived. The latter expression is used to estimate the extent of extra-hepatic drug elimination from the body.
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  • 13
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    Springer
    European journal of clinical pharmacology 11 (1977), S. 51-56 
    ISSN: 1432-1041
    Keywords: Antidepressive agent ; protriptyline ; plasma concentration ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma levels of protriptyline have been determined in 30 depressed female patients undergoing antidepressant therapy. After 3 1/2 weeks treatment at dosage levels of 40 mg/day, protriptyline plasma levels ranged from 430 to 1430 nmol/l. During this period only two-thirds of the subjects had definitely achieved asymptotic concentrations. Single dose studies in 5 volunteers suggest that the volume of distribution of protriptyline shows little intersubject variation. The half life of the drug, however, may vary appreciably from subject to subject, ranging from 54 to 198 h. The effects of two sedatives on mean protriptyline plasma levels have been determined. Mean plasma levels for nitrazepam recipients are indistinguishable from those for patients receiving no night sedation. The mean plasma levels for a group of patients receiving sodium amylobarbitone were significantly reduced. The problem of choice and early adjustment of dosages in order to achieve satisfactory plasma levels is discussed. For practical purposes it is suggested that early values may be of predictive significance in allowing early dosage adjustments to be made.
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  • 14
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    Springer
    European journal of clinical pharmacology 11 (1977), S. 473-477 
    ISSN: 1432-1041
    Keywords: Salicylate ; aspirin ; indomethacin ; pharmacokinetics ; coeliac disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma concentrations of salicylate and indomethacin were measured after a single oral dose of aspirin (600 mg) and indomethacin (50 mg) in twelve starved normal subjects and twelve adult patients with coeliac disease. The absorption of salicylate in the coeliac patients was faster than in the normal subjects. The plasma concentration/time curve of indomethacin in both groups was similar during the absorption phase, but there were significant differences between the groups in its elimination. The abnormal absorption pattern of salicylate in coeliac disease does not appear to be related to its pKa. Possible causes of the difference in salicylate absorption include changes in gastric emptying or altered small intestinal permeability.
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  • 15
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    European journal of clinical pharmacology 12 (1977), S. 205-208 
    ISSN: 1432-1041
    Keywords: Cetiedil ; vasodilator ; anticholinergic drug ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Cetiedil, a new vasodilating drug with anticholinergic properties, was shown to be metabolised very rapidly in man after intravenous and oral administration of the14C-compound. Higher concentrations of labelled compound after oral than after intravenous administration at the same sampling time, and proportional differences in urinary excretion, suggest that metabolic handling of the drug differs depending on the route of administration. Experiments in which inhibition of saliva secretion was measured indicated that (an) active metabolite(s) probably was (were) responsible for the action of the drug. As an anticholinergic drug, cetiedil is at least 400 times weaker than atropine.
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  • 16
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    Springer
    European journal of clinical pharmacology 12 (1977), S. 221-227 
    ISSN: 1432-1041
    Keywords: Cefuroxime ; cephalosporin antibiotics ; intravenous injection ; pharmacokinetics ; volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Cefuroxime, a new cephalosporin antibiotic which is stable to most β-lactamases produced by Gram-negative bacteria, was given by bolus intravenous injection to six volunteers in doses of 500 mg and 750 mg. The concentrations of cefuroxime in serum and urine were measured at pre-determined times after injection and the data analysed by a two-compartment open system model. A serum concentration of 8 µg/ml was exceeded for 100.3 min (±18.3) after a 500 mg dose and for 144.5 min (±19.8) after 750 mg. The ultimate serum half-life was 1.1 h. Excretion of cefuroxime in the urine was almost complete in 24 h, the clearance being 150 ml/min/1.73 m2. About 45% was excreted through the renal tubules. The injections were well tolerated and no changes in haematological or biochemical values were seen. The resulting data are compared with those published for some other cephalosporins. It is concluded that the favourable pharmacokinetics, especially the high concentrations of unbound cefuroxime in the serum, are likely to aid effective therapy of human infection caused by sensitive bacteria.
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  • 17
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    Springer
    European journal of clinical pharmacology 11 (1977), S. 91-99 
    ISSN: 1432-1041
    Keywords: Disopyramide ; plasma concentration ; cardiodepressant drugs ; ventricular arrhythmia ; ventricular tachycardia ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Ten patients with various heart diseases and ventricular arrhythmia received a single oral dose of disopyramide (DE) 200 mg. The ECG was recorded continuously for about 50 h from 2–4 h before drug administration. A statistically significant reduction in the number of ventricular ectopic beats (VEBs) was seen 1.0–3.5 h after drug intake; the average number of VEBs per 30 min decreased from 317 during the control period to 92 by 1.0–3.5 h after treatment and if one patient who did not respond is excluded, the corresponding figures were 272 and 14, respectively. Consecutive VEBs were seen in seven patients before DE was given and decreased significantly (p〈0.05) 1.5–5.5 h after drug administration. There was no change in the PQ interval, the QRS interval showed a slight increase, whereas the QT interval was prolonged 0.5–4 h after administration of DE. A specific gas chromatographic method was used for DE assay in plasma and urine. Absorption was rapid in all patients. Urinary excretion during the first 48 h after drug intake varied between 35 and 75%. The lowest effective antiarrhythmic concentration estimated in six patients ranged from 1.4 to 7.0 µg/ml. β-Phase half-life in five patients was between 10.3 and 22.1 h.
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  • 18
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    Springer
    European journal of clinical pharmacology 12 (1977), S. 73-76 
    ISSN: 1432-1041
    Keywords: Quinidine ; pharmacokinetics ; non-linearity ; dose-dependent pharmacokinetics ; steady state plasma level ; oral administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Quinidine was administrated orally to five healthy male volunteers. Doses of 0.2 g t. i. d., 0.3 g t. i. d. and 0.4 g t. i. d. were given for five days with at least four weeks between each test period. The plasma concentration of quinidine was measured before the morning dose on Days 2–5 of treatment, and 1, 2, 4 and 8 h after the morning dose on the 5th day. There was not a linear relationship between the increase in dose and the increase in plasma concentration of quinidine. A dose increase of 50% from 0.6 to 0.9 g quinidine sulphate per day resulted in an increase in steady state concentration of 94%. A further 33% increase in dose, from 0.9 to 1.2 g daily, resulted in a 55% increase in the steady stae concentration of quinidine. The results demonstrate dose-dependent pharmacokinetics for quinidine. Possible explanations for the nonlinear pharmacokinetics are discussed.
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  • 19
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    European journal of clinical pharmacology 12 (1977), S. 117-123 
    ISSN: 1432-1041
    Keywords: Methyldopa ; radioactive label ; pharmacokinetics ; metabolism ; healthy volunteers ; intravenous and oral administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of 2-14C-L-α-methyldopa have been investigated in five healthy volunteers following intravenous and oral administration. In the intravenous study a bi-phasic plasma concentration curve was found both for chemically determined α-methyldopa and for radioactivity. The plasma level of radioactivity differed significantly from chemically determined drug, a pattern which was also found in urine. This suggests the presence of unidentified metabolite(s). The difference between plasma disappearance and urine recovery of α-methyldopa and radioactivity during the first 4 h after injection suggests distribution to an extravascular compartment. Plasma half-lives of total radioactivity and of unchanged drug were calculated. In three subjects, pharmacokinetic parameters for a two-compartment open body model were calculated from urine and plasma data. Urinary recovery of radioactivity was almost complete within 48 h after intravenous administration. After oral administration, however, only about 40 per cent of the radioactive dose was recovered in the urine, and it contained approximately equal amounts of unconjugated methyldopa, acid-labile conjugated methyldopa and unidentified metabolite(s). The acid-labile conjugate was found only after oral administration, which supports the theory of a mucosal conjugation process. The lack of acid-labile conjugated drug either in the plasma or urine after intravenous injection indicates that there is no enterohepatic circulation of this drug.
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  • 20
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    European journal of clinical pharmacology 11 (1977), S. 283-286 
    ISSN: 1432-1041
    Keywords: Paracetamol ; Acetaminophen ; pharmacokinetics ; first-pass elimination ; intravenous administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Plasma paracetamol concentrations were measured in 6 volunteers after single intravenous (1000 mg) and oral (500 mg, 1000 mg and 2000 mg) doses of the drug. Paracetamol levels declined multiphasically with a mean clearance after intravenous administration of 352±40 ml/min. A two-compartment open model appeared to describe the decline adequately. Comparison of the areas under the plasma concentration-time curves (AUC) indicated that oral bioavailability increased from 0.63±0.02 after 500 mg, to 0.89±0.04 and 0.87±0.08 after 1000 mg and 2000 mg, respectively. As a consequence of the incomplete bioavailability of paracetamol, as well as its multicompartmental distribution, accurate estimates of its distribution volume and clearance cannot be obtained if the drug is given orally. However, an estimate of its total plasma clearance may be derived from the AUC after a 500 mg oral dose.
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  • 21
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    European journal of clinical pharmacology 11 (1977), S. 329-335 
    ISSN: 1432-1041
    Keywords: Digoxin ; pharmacokinetics ; two-compartment model ; radioimmunoassay ; neonates ; infants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The distribution and elimination of intravenous digoxin were investigated in seven neonates and infants with heart failure. Serum digoxin concentrations during a 24 h period were determined by radioimmunoassay, using125I as tracer. The serum values declined biexponentially after the injection and could be fitted to a two-compartment open model by non-linear least-squares regression. The calculated mean half-lives of the distribution (alpha) phase in neonates and infants were 37 and 28 min, respectively. The mean half-life of the elimination (beta) phase in neonates was 44 h, as compared to 19 h in infants. The mean volume of the central compartment and the mean volume of distribution at steady-state were calculated to be 1.3 and 9.9 l/kg, respectively; no significant differences between neonates and infants were found. The relation between these volumes indicates that digoxin is extensively distributed in tissues. The steady-state distribution volumes of digoxin in neonates and infants exceed those reported in adults. The larger volume of distribution might explain in part why infants with cardiac insufficiency require larger doses of digoxin than adults (on a mg/kg body weight basis) to obtain the same serum concentrations. Elimination of digoxin from the body was slower in neonates than in infants.
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  • 22
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    European journal of clinical pharmacology 11 (1977), S. 351-358 
    ISSN: 1432-1041
    Keywords: Phenprocoumon ; protein binding ; pharmacokinetics ; pharmacodynamics ; drug therapy ; myocardial infarction ; chronic disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In nine patients, the synthesis rate Rsyn of the vitamin K-dependent clotting factors was calculated from changes in prothrombin-complex activity after intravenous administration of a synthesis-blocking dose of phenprocoumon (PPC). The biological half-life of PPC was between 2.70 and 7.01 days. No correlation was found between the level of the free fraction of this strongly protein-bound drug and its biological half-life. There was a positive correlation (p〈0.01) between the size of the free fraction of PPC and the apparent volume of distribution of the drug. Four of the patients had had an acute myocardial infarction and they showed increased sensitivity to PPC. In them the plasma level of PPC sufficient to reduce Rsyn to 50% of R°syn was significantly lower, and the depression of individual vitamin K-dependent coagulation factors was more pronounced and prolonged, than in five other patients with chronic disease. The degradation rate of coagulation factors was also found to be higher in the patients with acute myocardial infarction. In four patients with chronic disease, anticoagulant therapy with PPC was continued in the out-patient clinic. The calculated oral maintenance dose of PPC, assuming complete absorption, first-order elimination kinetics and a linear relationship between the pharmacological effect and the logarithm of the PPC-plasma concentration, showed good agreement with the dose actually found to produce the desired PP% level.
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  • 23
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    European journal of clinical pharmacology 11 (1977), S. 367-375 
    ISSN: 1432-1041
    Keywords: Acenocoumarol ; excretory balance man ; pharmacokinetics ; biotransformation ; plasma protein binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The absorption, biotransformation and elimination of the anticoagulant acenocoumarol, 3-[α- (4′-nitrophenyl)-β-acetylethyl]-4-hydroxycoumarin, have been studied by oral administration of 12 mg of a14C-labelled preparation to two male volunteers. Absorption from the gastro-intestinal tract was rapid and the plasma concentration of unchanged drug reached a maximum of 169 and 412 ng/ml, respectively, after 3 hours. The elimination half-life in the two subjects, calculated from the decline between 6 and 24 h, was 8.7 and 8.2 hours. A constant proportion of 98.7% of the drug was bound in vitro to serum proteins over a concentration range of 0.021–8.34 µg/ml, with little interindividual variation. The major portion of the binding was to human serum albumin (97.5%) at two classes of binding sites: association constant K1=1.04×105 l/mole (n1=1) and K2=5.55×103 l/mole (n2=4). In addition to unchanged acenocoumarol, four metabolites were determined in plasma by isotope dilution techniques: the amino-, acetamido-, alcohol1- and alcohol2-metabolites. Of them, the amino-metabolite showed the highest concentration, namely 278 ng/ml, after 6 h in Subject A, and 163 ng/ml after 10 hours in Subject B. Judged from the integrated concentrations, the compounds analyzed accounted for 76 and 89%, respectively, of the total radioactivity in plasma. All the metabolites detected in plasma showed anticoagulant activity when tested in mice. The quantities of the metabolites excreted in urine from 0–120 hours were (Subject A/Subject B): acenocoumarol 0.3/0.2%, amino-metabolite 12.3/7.7%, acetamido-metabolite 19.0/11.1%, alcohol1-metabolite 4.6/9.0%, alcohol2-metabolite 1.7/4.4%, 6-hydroxy-metabolite 6.9/18.3% and 7-hydroxy-metabolite 14.0/22.2%.
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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 297-303 
    ISSN: 1432-1041
    Keywords: Hydrochlorothiazide ; pharmacokinetics ; dose/response relationship ; natriuresis ; kaliuresis ; calciuresis ; magnesiuresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Hydrochlorothiazide (hct) was administered orally in four different doses (12.5, 25, 50 and 75 mg), to eight healthy volunteers. Plasma and urine concentrations of hct were determined by GLC. Maximal plasma levels were found at 1.5–5 h, and averaged 70, 142, 260 and 376 ng × ml−1 respectively. The peak plasma levels and AUC0→9h of hct were highly correlated (p〈0.001) with the dose. The decline in the plasma curve was biphasic in those experiments in which the plasma levels of hct could be determined for at least 24 h. The half life of the slower phase lay between 5.6 and 14.8 h. The urinary recovery of hct, which represented the gastrointestinal absorption, averaged 65 to 72 per cent of the dose. The mean renal plasma clearance did not vary with the dose and averaged 319 to 345 ml × min−1. The diuresis during the 10 h after hct 12.5 mg exceeded that after placebo by a mean of 800 ml. The diureses was not increased further after higher doses of hct. The maximal natriuretic effect (+ 100 mmol), too, was found after the 12.5 mg dose. The excretion of potassium, however, rose with increasing doses; the maximal increment, after 75 mg hct, averaged 25 mmol. The excretion of calcium was significantly increased after 50 mg hct (+ 0.6 mmol). The maximal effect on magnesium excretion occurred after 25 mg hct (+ 0.5 mmol). In healthy volunteers there was no correlation between peak plasma level of hct or AUC0→9h and the renal excretion of water and electrolytes.
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  • 25
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 12 (1977), S. 305-310 
    ISSN: 1432-1041
    Keywords: Phenobarbital ; pharmacokinetics ; neonates ; infancy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary In 14 neonates 1–4 weeks old, 30 babies aged 1–12 months, and 7 infants of 1–5 years of age, the serum levels of phenobarbital were determined by a gas chromatographic micro-method after intravenous injection of phenobarbital 5–10 mg per kg body weight. It was possible to calculate the pharmacokinetic parameters using a two compartment open model. The distribution volumes within the individual age groups and the rate constants k12 and k21 showed no significant differences, but the elimination half-life was significantly longer in neonates (118.6±16.1 h) than in babies (62.9±5.2 h) or infants (68.5±3.2 h).
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  • 26
    ISSN: 1432-1041
    Keywords: Tolmetin ; pharmacokinetics ; bioavailability ; antacid ; oral dose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The purpose of this study was to determine whether a concomitant single dose of antacid or multiple doses of antacid administered prior to, and with tolmetin, alter the pharmacokinetics of tolmetin when the drug was administered as a commercially available tablet containing tolmetin sodium. The possible effects of the antacid on plasma concentrations and urinary excretion of tolmetin and its major metabolite were evaluated following administration of: (a) tolmetin sodium alone; (b) antacid four time a day for three days prior to a single dose of tolmetin sodium, with continuation of the antacid during the day tolmetin was given; and (c) co-administration of single doses of tolmetin sodium and antacid. The twenty-four subject study was of the crossover type. There were no significant differences among treatment means for: (i) peak plasma concentrations of both tolmetin and metabolite, (ii) AUC 0–8 h and AUC 0-∞ for both tolmetin and metabolite, (iii) time to peak plasma concentration for both tolmetin and metabolite, (iv) plasma concentrations of both tolmetin and the metabolite at all sampling times (except for tolmetin at 2 h), (v) renal clearance of both tolmetin and its metabolite, and (vi) the amount of metabolite excreted in the 0–24 h urine. There were small, but significant, differences among amounts of tolmetin excreted in the 0–24 h urine. Semilogarithmic plots of both tolmetin and metabolite plasma concentrations past the peak concentrations were curved over the entire 8-h observation period; although the elimination half-life of tolmetin has been reported to be about one hour, the half-life most probably exceeds 2.6 h in most subjects. The results of this study indicate a lack of a significant drug-drug interaction between the non-steroidal anti-inflammatory agent, tolmetin sodium, and a commonly used antacid, which is a mixture of magnesium and aluminium hydroxides.
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  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 5 (1977), S. 513-531 
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; nonlinear regression ; curve fitting ; computer program ; time sharing ; modeling ; weighting ; least squares ; parameter estimation ; discrimination between models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The problems of curve fitting and modeling in pharmacokinetics are discussed. A new nonlinear regression program FUNFIT, written for interactive time sharing, is presented which should be more reliable than programs based on the Gauss-Newton or other related gradient methods. The new program and the well-established program NONLIN were tested on two linear models using human plasma drug level data. FUNFIT found a substantially better solution than NONLIN in the majority of the cases.
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  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 5 (1977), S. 335-358 
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; perfusion models ; sampling ; parameter estimation ; computer program ; Org GB 94 ; mianserin ; Org GC 94
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A mathematical treatment of the influence of sampling on drug kinetics in liver perfusion is presented. Based on the derived equations, a Fortran IV computer program (PERFUS) is given, by which the time course of drug concentrations can be simulated for any sampling scheme. The simulations show that the withdrawal of large samples from the reservoir, i.e., larger than 5% of the reservoir volume, results in substantially biased parameters for drugs that are rapidly distributed and/or metabolized. For the fitting of empirical data, a Fortran IV computer program is given, based on BMDX85 nonlinear least squares by Gauss-Newton iterations. This program (PERFIT) estimates model parameters corrected as if no sampling had occurred, no matter how distorted the drug disappearance curve mày be as a result of sampling or due to degeneration of the two-compartment model into a one-compartment model. The conditions under which this degeneration occurs are discussed.
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  • 29
    Electronic Resource
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    Springer
    Journal of pharmacokinetics and pharmacodynamics 5 (1977), S. 111-122 
    ISSN: 1573-8744
    Keywords: hepatic clearance ; extraction ratio ; local anesthetics ; pharmacokinetics ; lidocaine ; bupivacaine ; etidocaine ; cardiovascular effects of local anesthetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Two independent methods of calculating hepatic drug clearance were applied to data from studies of the human pharmacokinetics of lidocaine, bupivacaine, and etidocaine. Within experimental limitations, agreement was good between estimates obtained by measurement of areas under blood drug concentration-time curves after rapid intravenous injection and by direct measurement of arterial and hepatic venous drug concentrations. Apparent hepatic extraction ratios of the agents followed the order etidocaine (∼0.73)/s〉lidocaine (∼0.68〉bupivacaine (∼0.37).Pharmacokinetic implications of increases in hepatic blood flow induced by the agents are discussed.
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  • 30
    ISSN: 1573-8744
    Keywords: chlordiazepoxide ; benzodiazepine ; two-compartment model, biopharmaceutics ; pharmacokinetics ; single dose ; routes of administration ; intravenous ; intramuscular ; oral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Single 30- mg doses of chlordiazepoxide HCl were administered to six healthy human subjects by the intravenous, oral, and intramuscular routes. Plasma concentration- time curves following intravenous administration were satisfactorily described by a biexponential equation consistent with a two-compartment open model system. Mean values of half-lives for the so-called distribution and elimination phases were 0.252 and 9.39 hr, respectively. The mean values for the volume of the central compartment (V 1) and volume of distribution $$(V_{d_\beta } )$$ were 18.0 and 30.9% of body weight, respectively. Following oral administration, the drug was rapidly and completely absorbed. Absorption was first order (t1/2≈27 min), and three of the six subjects showed a discernible lag time of approximately 20 min. Drug absorption following intramuscular administration was comparatively slow. A two- compartment “muscle model” comprised of precipitated and solubilized drug in the muscle was found to satisfactorily characterize the absorption process following administration by this route.
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  • 31
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    Springer
    Journal of pharmacokinetics and pharmacodynamics 5 (1977), S. 421-433 
    ISSN: 1573-8744
    Keywords: methotrexate ; pharmacokinetics ; model ; computer ; cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The infusion of high doses of methotrexate followed by folinic acid rescue is clinically useful against a variety of tumors. We studied the plasma pharmacokinetics of high-dose methotrexate infusions in patients with advanced cancer and devised a compartmental, kinetic model. our model is based on an earlier, mathematical model which describes the pharmacokinetics of moderate- to- high-dose methotrexate given as a single, intravenous injection. Mathematical equations for our model were solved on a UNIVAC1108 computer with the SAAM program. Seven compartments represent the distribution spaces for methotrexate and its metabolites. The transport of drug into and out of compartments is described by first-order differential equations. A nonlinear, concentration-dependent function is used for renal excretion with saturation of secretory and reabsorption mechanisms by methotrexate. Our model accurately depicts the pharmacokinetics of nine courses of therapy in five patients. The model can also be used to simulate the kinetics of methotrexate for patients with impaired renal function.
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  • 32
    ISSN: 1573-8744
    Keywords: gentamicin ; tissue distribution ; pharmacokinetics ; two-compartment modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Gentamicin pharmacokinetics was examined in a group of 47 patients with stable renal function treated an average of 10 days for severe infection. Serum concentrations rose continually during treatment, and declined in two phases after the drug was stopped, with a mean half-life of 112hr (range 27–693 hr) in the second phase. A two-compartment model was used to describe the biphasic decline in serum concentrations and to calculate the amount of drug in the tissue compartment at all times during and after treatment. Predicted tissue amounts of gentamicin rose continually on multiple dosing in all patients. In six patients who died, postmortem tissues were obtained to quantitate recovery. In all cases, the predicted amount of gentamicin in tissues was in close agreement with the amount recovered at autopsy. Tissue distribution and accumulation constitute a major reason for variability in gentamicin pharmacokinetics and explain both the rising peak and trough serum concentrations and the prolonged detection of gentamicin in serum and urine after the drug is stopped.
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  • 33
    ISSN: 1573-8744
    Keywords: chlordiazepoxide ; benzodiazepine ; two-compartment model ; multiple dosing ; pharmacokinetics ; biopharmaceutics ; metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Eight healthy male volunteers received chlordiazepoxide HCl orally at a dosage of 10 mg every 8 hr over a period of 21 days. On day 22, the regimen was changed to 30 mg every 24 hr for an additional 15 days. Plasma concentrations of chlordiazepoxide and its metabolites desmethyl-chlordiazepoxide, demoxepam, and desoxydemoxepam were measured during 14 of the 36 treatment days. Chlordiazepoxide plasma concentration- time data were consistent with first-order absorption and complete bioavailability. The harmonic mean absorption half-life was 12.3 min. Disposition of chlordiazepoxide was described by a two-compartment open model with a harmonic mean terminal exponential half-life of 10.1 hr. Average steady — state plasma levels of chlordiazepoxide, desmethylchlordiazepoxide, and demoxepam were approximately 0.75, 0.54, and 0.36 μg/ml, respectively.
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  • 34
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1-11 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation of Succinimide During the Synthesis of the Insulin A Chain(14-21) OctapeptideDuring the synthesis of insulin A chain (14-21) fragments it was observed that alkaline treatment of Msc-Cys(Trt)-Asn-OBut, Msc-Leu-Glu(OBut)-Asn-Tyr(But)-Cys(Trt)-Asn-OBut and Msc-Tyr-(But)-Gln-Leu-Glu(OBut)Asn-Tyr(But)-Cys(Trt)-Asn-OBut caused quantitative formation of succinimide in position 21.
    Notes: Bei der Synthese von Teilsequenzen der Insulin-A-Kette (14-21) wurde während der alkalischen Abspaltung der Msc-Gruppe von Msc-Cys(Trt)-Asn-OBut, Msc-Leu-Glu(OBut)-Asn-Tyr(But)-Cys-(Trt)-Asn-OBut und Msc-Tyr-(But)-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-Cys(Trt)-Asn-OBut in allen Fällen Succinimidbildung in Position 21 beobachtet.
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  • 35
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 37-48 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbene Reactions, IX. On the Reaction of Amide Acetals with HeterocumulenesDeprotonation of the (dimethylamino)methoxycarbenium ion (10) by NaH liberated the carbene 2, which was trapped by aryl isocyanate to give the hydantoin 6 and by phenyl isothiocyanate to yield 8. Hence, the carbene 2 is assumed to be also an intermediate in the corresponding reactions of the amide acetal 1 which lead to the hydantoins 6 and 8. The reaction of 1 with phenyl isothiocyanate yielded the products 4, 7, 8, or 12 depending on the reaction conditions. An equilibrium between 1 and the carbene 2 is suggested by the reaction of 1 with sulfur to give 16, and is the basis for mechanistic discussions.
    Notes: Das durch Deprotonierung des (Dimethylamino)methoxy-carbenium-Ions (10) mit NaH freigesetzte Carben 2 addierte sich an-Arylisocyanat zum Hydantoin 6, an Phenylisothiocyanat zu 8. Dies legt nahe, daß auch bei der Umsetzung des Amidacetals 1 mit Heterocumulenen zu den Hydantoinen 6 bzw. 8 das Carben 2 beteiligt ist. Bei der Umsetzung von 1 mit Phenylisothiocyanat entstanden je nach Reaktionsführung die Produkte 4, 7, 8 oder 12. Für deren Bildung werden Mechanismen diskutiert, die von einer Gleichgewichtseinstellung von 1 mit dem Carben 2 ausgehen. Diese Annahme wird durch Umsetzung von 1 mit Schwefel zu 16 gestützt.
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  • 36
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 67-77 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Perhalomethylthio)heterocycles, VIII. (Perchlorofluoromethylthio)- and (Haloformylthio)-N-heteroaromaticsPyrrole reacts with Cl3-nFnC—SCl (n = 1-3) to give mixtures of 2- and 3-substituted pyrroles 1 a-c and 2a, b; CF3SCFCl—SCl and XC(O)SCl (X = F, Cl) merely yield 2-substituted derivatives 3. In the presence of excess CF3SCl also disubstituted products 4, 5 are available. Analogously pyrrole derivatives can be substituted directly, dependent on their reactivity (6-14). 1a is oxidized by 3-chloroperbenzoic acid to yield the sulfoxide 15 or the sulfone 16; the reaction with bromine and iodine results in the formation of the fully halogenated compounds 17, 18. Indole reacts with CF3SCl to give the 3-substituted 19, while carbazole yields the N-substituted product 20 in a Grignard reaction. 1H and 19F n. m. r. spectra are discussed.
    Notes: Pyrrol setzt sich mit Cl3-nFnC—SCl (n = 1-3) zu Isomerengemischen 2- und 3-substituierter Pyrrole 1a-c bzw. 2a, b, um; CF3SCFCl—SCl und XC(O)SCl (X = F, Cl) liefern lediglich 2-substituierte Derivate 3. In Gegenwart eines CF3SCl-Überschusses sind auch disubstituierte Produkte 4, 5 erhältlich. Analog sind Pyrrol-Derivate, je nach ihrer Reaktivität, einer direkten Substitution zugänglich (6-14). 1 a wird durch 3-Chlorperbenzoesäure zum Sulfoxid 15 bzw. Sulfon 16 oxidiert; die Umsetzung mit Brom bzw. Iod führt zu den vollständig halogenierten Verbindungen 17, 18. Indol reagiert mit CF3SCl zum 3-substituierten 19, während Carbazol in einer Grignard-Reaktion das N-Substitutionsprodukt 20 liefert. 1H- und 19F-NMR-Spektren werden diskutiert.
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  • 37
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 96-106 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Aldehydes and Ketones with the Makosza Dichlorocarbene ReagentPhase transfer-catalyzed reactions of aldehydes and ketones with trichloromethane and 50 per cent aqueous sodium hydroxide in the presence of benzyltriethylammonium chloride (BTEA) at low temperatures result in the formation of α-(trichloromethyl)carbinols 7; in the presence of dimethyl sulfate the corresponding methyl ethers 8 are obtained. At 56 ± 2°C the α-hydroxy-11, α-chloro- 12 and α,β-unsaturated carboxylic acids 13 are formed. In this reaction the α-(trichloromethyl)carbinols 7 can be excluded as intermediates. An alternative reaction mechanism for the formation of 11, 12, and 13 is discussed, which involves direct addition of dichlorocarbene to the C=O double bond to form the dichlorooxiranes 5 followed by rearrangement and saponification.
    Notes: Aldehyde und Ketone reagieren mit Trichlormethan im Zweiphasensystem mit 50proz. wäßrigem Natriumhydroxid unter Phasentransfer-Katalyse durch Benzyltriethylammonium-chlorid (BTEA) (1) bei tiefer Temperatur zu α-(Trichlormethyl)carbinolen 7, in Gegenwart von Dimethylsulfat zu den entsprechenden Methylethern 8. Bei 56 ± 2°C entstehen α-Hydroxy- 11, α-Chlor- 12 und α,β-ungesättigte Carbonsäuren 13, wobei die α-(Trichlormethyl)carbinole 7 als Zwischen-stufen auszuschließen sind. Als Alternativmechanismus wird die direkte Addition von Dichlor-carben an die C=O-Doppelbindung zu Dichloroxiranen 5 und deren Umlagerung und Verseifung diskutiert.
    Additional Material: 2 Tab.
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  • 38
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 39
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 23-36 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbene Reactions, VIII. Selectivity of Nucleophilic Carbenes with Regard to HeterocumulenesThe selectivities of N-methylbenzothiazolinylidene (2) and 1,3-diphenylimidazolidinylidene (3) against aryl isocyanates and phenyl isothiocyanate have been determined. The selectivities increase from dimethoxycarbene (1) over 2 to 3. In contrast all three carbenes display equal selectivity with regard to different aryl isocyanates.
    Notes: Für N-Methylbenzothiazolinyliden (2) und 1,3-Diphenylimidazolidinyliden (3) wurden die Selektivitäten gegenüber verschiedenen Arylisocyanaten einerseits und Phenylisothiocyanat andererseits bestimmt. Diese nehmen vom Dimethoxycarben (1) über 2 zu 3 zu. Dagegen zeigen alle drei Carbene bei 140°C eine übereinstimmende Selektivität gegenüber Arylisocyanaten.
    Additional Material: 3 Ill.
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  • 40
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 12-22 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Metabolites of Microorganisms, XII. Michigazone, a New Phenoxazone Pigment from Streptomyces michiganensis  -  Structure Determination and SynthesisBy spectroscopic methods and chemical degradation michigazone has been shown to possess structure 7. 7 and some further related phenoxazones have been synthesized by the Kehrmann-method.
    Notes: Spektroskopische Untersuchungen und chemischer Abbau führten für Michigazon zur Konstitution 7. 7 und einige weitere bisher noch nicht beschriebene Phenoxazone wurden durch Kehrmann-Synthese dargestellt.
    Additional Material: 1 Ill.
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  • 41
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 49-52 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbene Reactions, X. Ionic Intermediates in the Reaction of Trimethyl Orthoformate with Aryl IsocyanatesThe ion pair 2/3 is assumed to be the crucial intermediate in the reaction of trimethyl orthoformate with aryl isocyanates. The collapse of the ion pair to 4 is a fast subsequent reaction. The acid base reaction of the ion pair to the carbene 6 proceeds with a comparable rate. Methoxyl transfer of 2/3 to form 1 is considerably slower. Transalkylation of the ion pair to 8 has not been observed.
    Notes: Bei der Umsetzung von Orthoameisensäure-trimethylester mit Phenylisocyanat wird das Ionen-paar 2/3 als zentrale Zwischenstufe angenommen. Eine rasche Folgereaktion dieses Ionenpaares ist die Kombination zu 4. Vergleichbar schnell verläuft die Säure-Basen-Reaktion im Ionenpaar zum Carben 6. Eine Methoxyl-Übertragung aus 2/3 zu 1 ist erheblich langsamer. Die Umalkylierung zu 8 konnte nicht beobachtet werden.
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  • 42
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 86-95 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Activated Ethylenes, V. Reaction of Aromatic Compounds with Derivatives of Chloromethylenemalonic Acid. A new Synthesis of Aromatic AldehydesThe derivatives of chloromethylenemalonic acid 3 and 4 react with aromatic compounds in the presence of aluminium chloride to give the arylmethylenemalonic acid derivatives 5a-i and 6a-d. By hydrolysis of the C=C double bond the corresponding dinitriles 2a-g are converted into aldehydes.
    Notes: Chlormethylenmalonsäure-Derivate 3 und 4 lassen sich in Gegenwart von Aluminiumchlorid mit Aromaten umsetzen, wobei die Arylmethylenmalonsäure-Derivate 5a-i und 6a-d entstehen. Die entsprechenden Dinitrile 2a-g lassen sich durch Hydrolyse der C=C-Doppelbindung in Aldehyde überführen.
    Additional Material: 8 Tab.
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  • 43
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 107-123 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of the Norcaradiene-Norcaradiene Rearrangement, I. The Synthesis of Optically Active [Norcaradiene ⇌ Cycloheptatriene] DerivativesAnion 14 derived from treatment of 1,3,5-cycloheptatriene-7-carbonitrile (13) with n-butyllithium or lithium diisopropyl reacts with methyl iodide, deuterium oxide, and carbon dioxide to give the corresponding 7,7-disubstituted derivatives 2, 13-D, and 16. By a sequence of reactions 2 was transformed into the optically pure [norcaradiene ⇌ cycloheptatriene] systems 4 and 10. The equilibrium concentrations of the [norcaradiene ⇌ cycloheptatriene] systems 2-12 were determined by 1H n.m.r. mesurements at low temperatures.
    Notes: Das aus 1,3,5-Cycloheptatrien-7-carbonitril (13) mit n-Butyllithium oder Lithium-diisopropylamid erzeugte Anion 14 reagiert mit Methyliodid, Deuteriumoxid und Kohlendioxid ausschließlich zu den entsprechenden 7,7-disubstituierten Derivaten 2, 13-D, und 16. Aus 2 lassen sich durch eine Folge von Reaktionen die optisch reinen [Norcaradien ⇌ Cycloheptatrien]-Systeme 4 und 10 synthetisieren. Mit Hilfe der Tieftemperatur-1H-NMR-Spektroskopie wurden die Gleichgewichtskonzentrationen der [Norcaradien ⇌ Cycloheptatrien]-Systeme 2-12 ermittelt.
    Additional Material: 3 Ill.
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  • 44
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 146-153 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with 4-Acetoxy-2-cyclopenten-1-oneBy using 4-acetoxy-2-cyclopenten-1-one (8) as a synthone for the non-existent cyclopentadienone (5), Michael additions are performed that give rise to trans-disubstituted cyclopentanone derivatives (11,12). In the case of tert-butyl acetoacetate as Michael donator the addition to 11 is followed by an aldol-cyclisation to the trans-perhydroazulene system 22.
    Notes: Unter Verwendung von 4-Acetoxy-2-cyclopenten-1-on (8) als Synthon für das nicht existenzfähige Cyclopentadienon (5) wurden Michael-Additionen durchgeführt, die zu trans-disubstituierten Cyclopentanon-Derivaten (11, 12) führen. Bei Verwendung von tert-Butyl-acetacetat als Michael-Donator schließt sich an die Addition zu 11 eine Aldolcyclisierung zum trans-Perhydroazulensystem 22 an.
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  • 45
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 605-610 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with 3,3-Bis(trifluoromethyl)-Δ4-1,4,2λ5-oxazaphospholines. Trapping Reactions of Nitrile Ylides with NitrosobenzeneTrapping reactions of bis(trifluoromethyl)-substituted nitrile ylides 2, generated by thermolysis of 3,3-bis(trifluoromethyl)-Δ4-1,4,2λ5-oxazaphospholines. 1, with nitrosobenzene yield 5,5-bis-(trifluoromethyl)-Δ3-1,2,4-oxadiazolines 3, 3,3-bis(trifluoromethyl)-Δ4-1,2,4-oxadiazolines 4, and 4,4-bis(trifluoromethyl)-1,4-dihydro-1-quinazolinols 5. The compounds 5 are products of a thermal rearrangement of first formed [3 + 2]-cycloadducts. I. r., 1H n. m. r., 19F n. m. r., and mass spectra of the new compounds are described.
    Notes: Abfangreaktionen von bis(trifluormethyl)-substituierten Nitril-yliden 2, die durch Thermolyse aus 3,3-Bis(trifluormethyl)-Δ4-1,4,2λ5-oxazaphospholinen 1 erzeugt werden, mit Nitrosobenzol liefern 5,5-Bis(trifluormethyl)-Δ3-1,2,4-oxadiazoline 3, 3,3-Bis(trifluormethyl)-Δ4-1,2,4-oxadiazoline 4 und 4,4-Bis(trifluormethyl)-1,4-dihydro-1-chinazolinole 5. Die Verbindungen 5 sind das Resultat einer thermisch ausgelösten Umlagerung primär erhaltener [3 + 2]-Cycloaddukte. IR-, 1H-NMR-, 19F-NMR- und Massenspektren der neuen Verbindungen werden beschrieben.
    Additional Material: 4 Tab.
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  • 46
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 619-630 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Systems, XXIV. Benzo[12]annulenes: On the Annulene Character of Dibenzo- and Tribenzo[12]annulenesAs a contribution to the controversial discussion about the antiaromaticity of the [12]annulene system in the di- and tribenzo[12]annulenes 3 and 4 the compounds 5, 8, and 18 were prepared for comparison. The discussion of the 1H n. m. r. spectra with consideration of the anisotropy effect of the triple bonds led to the conclusion that in contrast to earlier assumptions the [12]annulene system in 3 and 4 in spite of the benzo-anellation is paratropic.
    Notes: Als Beitrag zu der kontroversen Diskussion über die Antiaromatizität des [12]Annulen-Systems in den Di- und Tribenzo[12]annulenen 3 und 4 wurden die Vergleichsverbindungen 5, 8 und 18 dargestellt. Die Diskussion der 1H-NMR-Spektren unter Berücksichtigung des Anisotropieeffektes der Dreifachbindungen ergab, daß entgegen früherer Auffassung das [12]Annulen-System in 3 und 4 trotz der Benzo-Anellierung paratrop ist.
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  • 47
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 631-637 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Systems, XXV. Benzo[12]annulenes: Synthesis and Properties of a Benzo-naphtho[12]annuleneThe benzo-naphtho[12]annulene 4, where in contrast to 1, 2, and 3 a planar twelve-membered ring is present, has been synthesized via 6-9. 1H n. m. r. absorption of the internal hydrogen is observed at δ = 13.13 ppm. The allotment of this considerable down-field shift to the paratropic effect of the annulene system and the anisotropy of the triple bonds is discussed. For this purpose, the twelve-ring system 5 in which the macrocyclic conjugation is interrupted has been synthesized from 9 via 10 and 11.
    Notes: Das Benzo-naphtho[12]annulen 4, bei dem im Gegensatz zu den Verbindungen 1, 2 und 3 eine ebene Zwölfring-Struktur fixiert ist, wurde über 6-9 synthetisiert. Die 1H-NMR-Absorption des inneren Wasserstoffatoms wird bei δ = 13.13 ppm beobachtet. Die Aufteilung dieser beträchtlichen Tieffeld-Verschiebung in den Paratropie-Effekt des Annulen-Systems und den Anisotropie-Effekt der Dreifachbindungen wird diskutiert. Hierzu wurde das Zwölfring-System 5, bei dem die makrocyclische Konjugation unterbrochen ist, von 9 über 10 und 11 synthetisiert.
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  • 48
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 651-655 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Anionic Cycloadditions, XV. Reactions of trans,trans-1,3-Diphenyl-2-azaallyllithium with Heterocumulenestrans,trans-1,3-Diphenyl-2-azaallyllithium (1) reacts with phenylisocyanate, phenylisothiocyanate, and methylisothiocyanate to give an imidazolidine-4-one (2a) or imidazolidine-4-thione (2b, c), respectively. When reacting with carbon disulfide or dicyclohexylcarbodiimide (symmetrical heterocumulenes) the cycloaddition is followed by a fast secondary reaction (→ 4, 7).
    Notes: trans,trans-1,3-Diphenyl-2-azaallyllithium (1) cycloaddiert sich regiospezifisch an die CN-Doppel-bindung des Phenylisocyanats sowie Phenyl- und Methylisothiocyanats unter Bildung eines Imidazolidin-4-ons (2a) bzw. -4-thions (2b, c). Bei entsprechenden Umsetzungen mit den symmetrischen Heterokumulenen Schwefelkohlenstoff und Dicyclohexylcarbodiimid folgt der Cycloaddition jeweils eine schnelle Sekundärreaktion (→4, 7).
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  • 49
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 667-676 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of trans-[Pt(CO2R)(CO)(PPh3)2]+BF4- with Alkynes: Formation of Alkynyl- and Alkenylplatinum(II) ComplexesThe alkoxycarbonyl complexes [Pt(CO2R)(CO)(PPh3)2]+ BF4- 1 react with alkynes HC≡CR to give the acetylides 2a-c. On the other hand, cationic β-methoxyvinyl 3 or β-hydroxyvinyl complexes 4, respectively, are obtained from the reactions of 1 with disubstituted acetylenes R1C≡CR2 under participation of the nucleophiles methanol and water. Compounds 3 and 4 are converted into neutral derivatives (5, 6, 8) by methoxide or azide ions. The synthesis of Ir(CO2CH3)(CO)(CH3O2CC≡CCO2CH3)[P(CH3)Ph2]2 is described. Bonding is discussed for the new complexes by means of n. m. r. and i. r. data.
    Notes: Die Alkoxycarbonyl-Komplexe [Pt(CO2R)(CO)(PPh3)2]+BF4- 1 setzen sich mit Alkinen HC ≡ CR zu den Acetyliden 2a-c um. Dagegen entstehen aus 1 und disubstituierten Acetylenen R1C≡CR2 unter Beteiligung der Nucleophile Methanol und Wasser kationische β-Methoxyvinyl- 3, bzw. β-Hydroxyvinyl-Komplexe 4. Die Verbindungen 3 und 4 werden mit Methylat- oder Azid-Ionen in neutrale Derivate (5, 6, 8) umgewandelt. Ferner wird die Synthese von Ir(CO2CH3)(CO)-(CH3O2CC≡CCO2CH3)[P(CH3)Ph2]2 beschrieben. Die Bindungsverhältnisse werden mit Hilfe von NMR- und IR-Daten diskutiert.
    Additional Material: 3 Tab.
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  • 50
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 703-716 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Double Bridged 5,6-Diamino-4,7-dialkyl-1,3-benzodioxoles as Intermediates for the Synthesis of Molecules with Knot StructureIn a reaction sequence involving metalation with butyllithium followed by alkylation. cyclohexanone pyrocatechol acetal 4 is converted to the 3,6-dialkylpyrocatechol 11. By subsequent acetalisation with 1,25-dichloro-13-pentacosanone (14), followed by nitration (19), reduction (20), acylation (26), renewed reduction (27), and cyclization, the double bridged benzodioxole 28 is obtained. The compound represents an intermediate in the projected synthesis of a molecule with knot structure.
    Notes: Ausgehend vom Cyclohexanon-brenzcatechinacetal 4 wird durch Metallierung mit Butyllithium und nachfolgende Alkylierung in einer mehrstufigen Reaktionsfolge das 3,6-Dialkylbrenzcatechin 11 synthetisiert. Durch nachfolgende Acetalisierung mit 1,25-Dichlor-13-pentacosanon (14), gefolgt von Nitrierung (19), Reduktion (20), Acylierung (26), erneuter Reduktion (27) und Cyclisierung wird das zweifach überbrückte Benzodioxol 28 erhalten. Es stellt ein Zwischenprodukt in der geplanten Synthese eines Moleküls mit Knotenstruktur dar.
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  • 51
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 463-467 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Directed Synthesis of Sulfinato-O and -S Complexes of Some Transition Metals, XIV Sulfinato-O,S Complexes of Palladium(II) and Rhodium(III)The directed preparation of the sulfinato-O,S complexes {R(O)OS}nM (2a, b; 5a, b) was successful for the first time by elimination of coordinated water from the sulfinato-S complexes {RS(O)2}nM(OH2)n [n = 2, M = Pd (1a, b); n = 3, M = Rh (4a, b)] by 2,2-dimethoxypropane. The O,S-linkage is unequivocally shown from their chemical behaviour and the i. r. spectra. The criteria necessary for the formation of sulfinato-O,S complexes are discussed.
    Notes: Durch Abspaltung von koordiniertem Wasser aus den Sulfinato-S-Komplexen {RS(O)2}nM(OH2)n [n = 2, M = Pd (1a, b); n = 3, M = Rh (4a, b)] mit 2,2-Dimethoxypropan gelang erstmals die gezielte Darstellung der Sulfinato-O,S-Komplexe {R(O)OS}nM (2a, b; 5a, b). Die O,S-Verknüpfung ergibt sich eindeutig aus dem chemischen Verhalten und den IR-Spektren. Die für die Bildung von Sulfinato-O,S-Komplexen notwendigen Kriterien werden diskutiert.
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  • 52
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 474-486 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, 78 Further Constituents of South African Senecio SpeciesFrom representatives of the section Rigidi besides already known compounds four new benzofurans (3, 5, 6, and 10) as well as six new furanoeremophilanes (13, 15, 19-21, and 23) are isolated. From Senecio pterophorus a new type of a pyrrolizidine derivative (25) is isolated. Senecio cissampelinus contains similar compounds (34-37). The structures are elucidated by spectroscopic methods as well as by some chemical reactions. The chemotaxonomical aspects are discussed.
    Notes: Aus Vertretern der Sektion Rigidi werden neben bereits bekannten Verbindungen vier neue Benzofurane (3, 5, 6 und 10) sowie sechs neue Furanoeremophilane (13, 15, 19-21 und 23) isoliert. Aus Senecio pterophorus wird ein neuer Typ eines Pyrrolizidin-Derivats (25) isoliert. Ähnliche Verbindungen (34-37) enthält Senecio cissampelinus. Die Konstitutionen werden durch spektroskopische Methoden sowie durch einige chemische Reaktionen geklärt. Die chemotaxonomischen Aspekte werden diskutiert.
    Additional Material: 6 Tab.
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  • 53
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 491-499 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Monohydrazones of Dicarbonyl Compounds, IV. New Syntheses of Pyrroles and PyrrolinesKetones and aldehydes with an active methylene group condense easily with monohydrazones of glyoxal (1 + 2 → 3). The hydrazonoethylidene derivatives thus obtained can be reduced to give pyrroles, pyrrolines, pyrrolidines, or N-aminopyrroles.
    Notes: Methylenaktive Ketone und Aldehyde lassen sich mit Monohydrazonen des Glyoxals zu Hydrazonoethyliden-Derivaten umsetzen (1 + 2 → 3). Durch Reduktion dieser Produkte sind Pyrrole, Pyrroline, Pyrrolidine sowie N-Aminopyrrole darstellbar.
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  • 54
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 522-539 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Dipolar Cycloadditions, 78. Additions of C-(2,2′-Biphenylylene)-Nα-(4-chlorophenyl)-Nβ-cyano-azomethine Imine to Styrene, Alkenes, Enol Ethers and EnaminesThe cycloaddition of the title compound 1 to styrene at 70°C produces 95% of a pyrazolidine; the hydrogenolytic degradation to 9-phenethylfluorene as well as the n. m. r. spectrum reveal the addition direction. The 1-cyanopyrazolidine derivative shows reactions typical for cyanamides. - The azomethine imine 1 likewise accepts many nonconjugated alkenes, cycloalkenes and derivatives of styrene in high yield. The cycloadducts of butyl vinyl ether, cis- and trans-propenyl propyl ether, β-methoxystyrene and vinyl acetate suffer with dilute acids elimination of alkoxide or acetate, respectively, and of the N-cyano group to yield 2-pyrazolines. The electrophilicity of the azomethine imine carbon center determines the addition direction; substituents on the ethylenic dipolarophile which stabilize positive charge in the transition state of cycloaddition show up in position 5 of the pyrazolidine.
    Notes: Die Cycloaddition der Titelverbindung 1 an Styrol bei 70°C ergibt 95% eines Pyrazolidins; die Additionsrichtung geht aus der Hydrogenolyse zu 9-Phenethylfluoren ebenso wie aus dem NMR-Spektrum hervor. Das 1-Cyanpyrazolidin zeigt für Cyanamide typische Reaktionen. - Das Azomethin-imin 1 addiert viele nichtkonjugierte Alkene, Cycloalkene und Derivate des Styrols in hoher Ausbeute, wobei spektroskopische Daten die Addukt-Strukturen sichern. Die Cycloaddukte des Butylvinylethers, cis- und trans-Propenylpropylethers, β-Methoxystyrols und Vinylacetats erleiden schon mit verdünnter Säure eine Eliminierung des Alkoxyls bzw. Acetats und des N-Cyans unter Bildung von 2-Pyrazolinen. Die Additionsrichtung des 1,3-Dipols wird von der Elektrophilie des Azomethin-imin-Kohlenstoffs bestimmt; Substituenten am ethylenischen Dipolarophil, die positive Ladung im Übergangszustand der Cycloaddition zu stabilisieren vermögen, erscheinen in 5-Stellung des Pyrazolidins.
    Additional Material: 3 Ill.
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  • 55
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 611-618 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of 2,2,2-Trifluor-4,4,5,5-tetrakis(trifluormethyl)-1,3,2λ5-dioxaphospholanePF5 and PhPF4 react with 2-[bis(trimethylsilyl)amino]-2,2-difluoro-4,4,5,5-tetrakis (trifluoromethyl)-1,3,2λ5-dioxaphospholane (1b) to yield the trifluorophosphorane 2 or 3, respectively. 3 is the first known example of a stable fluorophosphazophosphorane. 2 reacts with methoxytrimethylsilane to give the thermally stable difluoromethoxyphosphorane4; with hexamethyldisiloxane 5 is obtained. PF5 easily converts 5 into 2. Diphenyl(trimethylsilyl)phosphine reduces 2 to the cyclic fluorophosphite 6, which displaces the coordinated cycloolefin in (C7H8)Mo(CO)4 (C7H8 = norbornadiene) with formation of the cis-complex 7. The spectroscopic data are discussed.
    Notes: Die Reaktion von PF5 bzw. PhPF4 mit 2-[Bis(trimethylsilyl)amino]-2,2-difluor-4,4,5,5-tetrakis-(trifluormethyl)-1,3,2λ5-dioxaphospholan (1b) ergibt das Trifluorphosphoran 2 bzw. 3, das erste stabile Fluorphosphazophosphoran. 2 setzt sich mit Methoxytrimethylsilan zu dem thermisch beständigen Difluormethoxyphosphoran 4 um, mit Hexamethyldisiloxan entsteht 5, das mit PF5 leicht in 2 umgewandelt werden kann. Diphenyl(trimethylsilyl)phosphin reduziert 2 zu dem cyclischen Fluorphosphit 6, das in (C7H8)Mo(CO)4 (C7H8 = Norbornadien) das Cycloolefin unter Bildung des cis-Komplexes 7 substituiert. Die spektroskopischen Daten werden diskutiert.
    Additional Material: 2 Tab.
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  • 56
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 638-644 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Anionic Cycloadditions, XIII. endo-exo-Isomeric Cycloadducts of trans,trans-1,3-Diphenyl-2-azaallyllithium and Acenaphthylenetrans,trans-1,3-Diphenyl-2-azaallyllithium adds at O or -70°C to acenaphthylene with retention of configuration to give a mixture of N-lithio-syn- and N-lithio-anti-7,9-diphenyl-7,8,9,9a-tetrahydro-6bH-acenaphtho[1,2-c]pyrrole (3a, 4a, R = Li) (ca. 1:1). The syn-isomer (endo-cycloadduct) rearranges to the anti-isomer (exo-cycloadduct) at +35°C.
    Notes: trans,trans-1,3-Diphenyl-2-azaallyllithium (1) cycloaddiert sich bei O oder -70°C unter Retention an Acenaphthylen zu einem Gemisch von N-Lithio-syn- und N-Lithio-anti-7,9-diphenyl-7,8,9,9a-tetrahydro-6bH-acenaphtho[1,2-c]pyrrol (3a, 4a, R = Li) (ca. 1:1). Das syn-Isomere (endo-Cycloaddukt) lagert sich bei +35°C in das anti-Isomere (exo-Cycloaddukt) um.
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  • 57
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 677-682 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Some Simple Phosphorus and Arsenic Ylides with Methylgermanium, -tin, and -lead SubstituentsThe syntheses of the ylides (CH3)3P = C[Pb(CH3)3]2, (CH3)3P = C[Ge(CH3)3]2, and (CH3)2-[(CH3)3GeCH2]P = C[Ge(CH3)3]2 are reported. The relative substituent effect of all IVb elements on the carbanionic function of ylides is discussed in the light of the 13C and 31P n. m. r. spectra of these compounds and their Si and Sn analogues.
    Notes: Die Darstellung der Ylide (CH3)3P = C[Pb(CH3)3]2, (CH3)3P = C[Ge(CH3)3]2 und (CH3)2-[(CH3)3GeCH2]P = C[Ge(CH3)3]2 wird beschrieben. Der relative Substituenteneffekt aller IVb-Elemente auf die Carbanion-Funktion von Yliden wird an Hand der 13C- und 31P-NMR-Spektren dieser Verbindungen und ihrer Si- und Sn-Analoga diskutiert.
    Additional Material: 1 Ill.
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  • 58
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 717-720 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal Alkyl and Aryl Compounds, XIX. Preparation and Crystal Structure of Methylrubidium and MethylcaesiumCH3Rb and CH3Cs are prepared from CH3Li and rubidium tert-butoxide or caesium 2-methyl-2-pentanolate, respectively. As shown by X-ray diffraction of the crystal powders the compounds possess a hexagonal structure of the NiAs type with isolated methyl anions and alkali cations like CH3K investigated earlier.
    Notes: CH3Rb und CH3Cs werden durch doppelte Umsetzung von CH3Li mit Rubidium-tert-butylat bzw. Caesium-2-methyl-2-pentanolat dargestellt. Nach röntgenographischen Untersuchungen der Kristallpulver besitzen die Verbindungen wie das bereits früher untersuchte CH3K eine hexagonale Struktur vom NiAs-Typ mit isolierten Methyl-Anionen und Alkali-Kationen.
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  • 59
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 730-736 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mass Spectrometrical Investigations of Dicarbonyl(cyclopentadienyl)(thioamidato) Complexes of Molybdenum and TungstenThe mass spectra of several dicarbonyl(cyclopentadienyl)(thioamidato) complexes of Mo and W and of the corresponding free thioamides are reported and the fragmentation processes are discussed. The fragmentation modes of the ionized complexes reveal structural rearrangements of the organic ligands, which cannot be observed in the spectra of the free thioamides.
    Notes: Die Massenspektren einiger Dicarbonyl(cyclopentadienyl)(thioamidato)-Komplexe von Mo und W und die der zugehörigen freien Thioamide werden angegeben und die Fragmentierungsprozesse diskutiert. Der organische Ligand unterliegt im ionisierten Komplex tiefgreifenden strukturellen Umlagerungen, für die sich in den Spektren der freien Thioamide keine Parallele finden läßt.
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  • 60
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 744-748 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Intramolecular Interactions of Triple Bonds, XVI. The Crystal and Molecular Structure of 5,6,12,13-Tetradehydro-8,9,10,11-tetrahydro-7H-dibenzo-[a,c]cyclotrideceneThe crystal structure of the title compound was solved by direct methods and has been refined to R = 0.056. The triple bonds are crossed by an angle of 64.0°. Their centres have a distance of 3.174 Å. Because of transannular repulsion within the thirteen-membered ring system the acetylene group deviates by 4.1° and 4.6° respectively in a cisoid manner from a linear arrangement. The other angles are enlarged. In the present conformation the length of the [CH2]5-bridge corresponds the length of the CH2—S—S—CH2-group. The chiral molecule lies on a crystallographic twofold axis.
    Notes: Die Kristallstruktur der Titelverbindung wurde mit direkten Methoden gelöst und bis zu einem R-Wert von 0.056 verfeinert. Die Dreifachbindungen sind unter einem Winkel von 64.0° gekreuzt angeordnet und zeigen einen Mittelpunktsabstand von 3.174 Å. Auf Grund der transannularen Abstoßung innerhalb des dreizehngliedrigen Ringsystems ist die Acetylengruppe um 4.1° bzw. 4.6° aus der linearen Anordnung cisoid deformiert. Die übrigen Winkel sind aufgeweitet. Die Länge der [CH2]5-Brücke entspricht in der vorliegenden Konformation der einer CH2—S—S—CH2-Gruppe. Das chirale Molekül liegt auf einer zweizähligen kristallographischen Achse.
    Additional Material: 1 Ill.
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  • 61
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 693-702 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Question of Inner Hexacoordination with Pentaarylphosphoranes; Phosphorane Rearrangements at the Level of Coordination Number 5The spirocyclic pentaarylphosphoranes 13 and 18b containing hydroxy groups in the direct neighbourhood of the molecule centre, isomerize more or less readily to the oxyphosphoranes 14 and 22, resp., with retention of coordination number 5. Inner onium-ate complexations could not be detected with the starting materials.
    Notes: Die spirocyclischen Pentaarylphosphorane 13 und 18b, die in unmittelbarer Nachbarschaft zum Molekülzentrum Hydroxylgruppen aufweisen, isomerisieren mehr oder weniger leicht unter Beibehaltung des Koordinationsniveaus 5 zu den Oxyphosphoranen 14 bzw. 22. Innere Onium-At-Komplexierungen konnten bei den Ausgangsverbindungen nicht nachgewiesen werden.
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  • 62
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 683-692 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of 1,3,5-Trifluoro-1,3,5-trioxo-1λ6,3λ6,5λ6,2,4,6-trithiatriazine (Sulfanuric Fluoride) with AminesWhereas the reaction of the trithiatriazine 1 with diethylamine yields only mono- and disubstituted derivatives (2b, 3), the reaction with dimethylamine results in the replacement of one, two, or three fluorine atoms (→ 2a, 3a, 4). On the other hand, only mono- or trisubstituted compounds (5a, b or 9a, b, resp.), are formed by the reactions of 1 with primary amines such as methylamine and ethylamine. Ammonia reacts with 1 to give 10·NH3. The free compound 10 is formed by treatment with HCl gas. 10 reacts with P(C6H5)4Cl to yield the ionic compound 11 and with benzaldehyde to form the Schiff base 12. With secondary diamines 1 preferentially undergoes intermolecular linkage with formation of 13, but a bicyclic compound 14 could also be prepared in low yield. 1 reacts with silylamines such as RN(SiMe3)2 (R = CH3, C2H5) only after addition of RNH(SiMe3) (→ 15a, b). Sn—N cleavage reactions with 1 occur more readily. Only monosubstituted products (e. g. 16) are formed. Reaction of 1 with phenylhydrazine results in reduction of a sulfur atom and formation of the anion 17. A substituted anion (18) was also prepared from 2a by this method. The reaction behavior of 1 is discussed in detail.
    Notes: Während das Trithiatriazin 1 mit Diethylamin nur zu Mono- und Disubstitutionsderivaten (2b, 3b) reagiert, kann Dimethylamin ein, zwei oder auch drei Fluoratome austauschen (→2a, 3a, 4). Die Reaktion von 1 mit primären Aminen wie Methylamin und Ethylamin liefert hingegen nur Mono- und Trisubstitutionsprodukte (5a, b bzw. 9a, b). Ammoniak reagiert mit 1 zu 10·NH3, die freie Verbindung 10 entsteht nach Behandeln mit HCl-Gas. Mit P(C6H5)4Cl gibt 10 die ionische Verbindung 11, mit Benzaldehyd die Schiffsche Base 12. Mit sekundären Diaminen setzt sich 1 bevorzugt unter intermolekularer Verknüpfung (13) um, aber auch eine bicyclische Verbindung 14 ist in geringer Ausbeute darzustellen. Mit Silylaminen wie RN(SiMe3)2 (R = CH3, C2H5) reagiert 1 erst nach Zusatz von RNHSiMe3 (→ 15a, b). Sn-N-Spaltungsreaktionen mit 1 verlaufen erheblich leichter, wobei ausschließlich Monosubstitutionsprodukte (z. B. 16) gebildet werden. 1 gibt mit Phenylhydrazin unter Reduktion eines Schwefelatoms das Anion 17. Auch ein substituiertes Anion (18) konnte auf diesem Wege aus 2a dargestellt werden. Das Reaktionsverhalten von 1 wird ausführlich diskutiert.
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  • 63
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the 8-, 4′-, and 7-Monomethyl Ethers of Gossypetin (3,3′,4′,5,7,8-Hexahydroxyflavone) and Structure of Ranupenin from Ranunculus repens L.By synthesis of 8-, 4′- and 7-O-monomethylgossypetin via a modified Allan-Robinson condensation as well as directly from gossypetin (3,3′,4′,5,7,8-hexahydroxyflavone), it is shown that ranupenin from Ranunculus repens L., which occurs in the plant as an O-monogalactoside, has the structure not of 8-O-monomethyl- but of 7-O-monomethylgossypetin.
    Notes: Durch die Synthese von 8-, 4′- und 7-O-Monomethylgossypetin über eine modifizierte Allan-Robinson-Kondensation bzw. direkt aus Gossypetin (3,3′,4′,5,7,8-Hexahydroxyflavon) konnte geklärt werden, daß dem als O-Monogalactosid natürlich vorliegenden Ranupenin aus Ranunculus repens L. nicht die Konstitution eines Gossypetin-8-, sondern -7-methylethers zukommt.
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  • 64
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 773-777 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular Mechanics Calculations on the Stability of Bridgehead OlefinsEmpirical force field calculations were used to determine the limits of application of the rules proposed by Fawcett Wiseman and Köbrich for the stability of bridgehead olefins (Bredt compounds). The stability is ruled by the size of the trans-cycloolefin unit, whereas the sum of the number of atoms in the three bridges is of minor importance. With a given skeleton the double bond was found less favourable in the largest bridge than in the second largest in most cases studied.
    Notes: Mittels empirischer Kraftfeldrechnungen wird der Gültigkeitsbereich der Regeln von Fawcett, Wiseman und Köbrich zur Vorhersage der Stabilität von Brückenkopfolefinen (Bredt-Verbindungen) untersucht. Die Größe der trans-Cycloolefineinheit ist für die Stabilität ausschlaggebend, die Summe der Ringgliederzahl in den drei Brücken ist von untergeordneter Bedeutung. Bei gegebenem Gerüst ist in der Mehrzahl der untersuchten Moleküle die Doppelbindung in der größten Brücke weniger günstig als in der zweitgrößten.
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  • 65
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 816-819 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Borabenzene Derivatives, IX. Paramagnetic Chromium Complexes of 1-Methylborinate and 1-Phenylborinate IonsPotassium borinates, K[C5H5B-R] (R = CH3, C6H5), react with CrCl3 or CrCl2·THF to give paramagnetic bis(borinato)chromium complexes, Cr(C5H5B-R)2 (R = CH3, C6H5). For these a sandwich structure with a 16-electron valence shell is proposed.
    Notes: Durch Umsetzung von Kaliumborinaten, K[C5H5B-R] (R = CH3, C6H5), mit CrCl3 oder CrCl2·THF werden paramagnetische Bis(borinato)chrom-Komplexe, Cr(C5H5B-R)2 (R = CH3, C6H5), erhalten. Für diese wird eine Sandwich-Struktur mit einer 16-Elektronen-Valenzschale vorgeschlagen.
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  • 66
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 994-999 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Some Reactions of Hydroxy-N,N-dimethylcarboxamides3-Hydroxy-N,N-dimethyl-1-carboxamides (2, 7) are converted into the corresponding γ-butyrolactones (3, 8) by treatment with an acidic ion-exchange resin in acetone or by thermolysis. 2-Hydroxy-N,N-dimethyl-1-carboxamides (10, 12, 14, 16b, 18) on the contrary form the corresponding carbonyl compounds (9, 11, 13, 15b, 17).
    Notes: 4-Hydroxycarbonsäure-dimethylamide (2, 7) lassen sich durch Behandlung mit saurem Ionenaustauscher in Aceton oder durch Thermolyse in die entsprechenden γ-Butyrolactone(3,8) überführen. 3-Hydroxycarbonsäure-dimethylamide (10, 12, 14, 16b, 18) bilden hingegen beim Erwärmen die entsprechenden Carbonylverbindungen (9, 11, 13, 15b, 17) zurück.
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  • 67
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complex Chemistry of Reactive Organic Compounds, XIV. The Reactions of Aliphatic Diazo Compounds with the Tricarbonyl(cyclopentadienyl) Hydrides of Molybdenum and TungstenDepending on their constitution, aliphatic diazo compounds 3 behave differently in their reactions with tricarbonyl(cyclopentadienyl)hydridomolybdenum (1) and -tungsten (2). Diazomethane (3a), diazoethane (3b), and 2-diazopropane (3c) are stabilized as alkane diazo ligands in complexes of the type C5H5M(CO)2[N2CHR1R2] (M = Mo: 6; M = W: 7). Phenyl-, (4-nitrophenyl)-, (4-methoxyphenyl)diazomethane (3d, e, f), and 9-diazofluorene (3g) form in clean reactions the carbene insertion products C5H5M(CO)3CHR1R2 (M = Mo: 4; M = W: 5), whereas ω-diazoacetophenone (3h) and diazodimedone (3i) yield the binuclear diazo complexes C5H5M(CO)3-M(CO)2C5H5[N2 = CR1R2] (M = Mo: 9; M = W: 10). Diethyl diazomalonate (3h) is coordinated as an imino-amido ligand in the coordination compound 14 which arises from a 1,1-insertion of 3k into the polar tungsten-hydrogen bond of 2.
    Notes: In ihrer Reaktivität gegenüber Tricarbonyl(cyclopentadienyl)hydridomolybdän (1) und -wolfram (2) weisen Diazoalkane 3 starke konstitutionsbedingte Unterschiede auf: Diazomethan (3a), Diazoethan (3b) und 2-Diazopropan (3c) werden als Alkandiazo-Liganden in Komplexen vom Typ C5H5M(CO)2[N2CHR1R2] (M = Mo: 6; M = W: 7) stabilisiert; Phenyl-, (4-Nitrophenyl)-, (4-Methoxyphenyl)diazomethan (3d, e, f) sowie 9-Diazofluoren (3g) bilden in glatten Reaktionen die Carben-Insertionsprodukte C5H5M(CO)3CHR1R2 (M = Mo: 4; M = W: 5), während ω-Diazoacetophenon (3h) wie auch Diazodimedon (3i) die zweikernigen Diazoketon-Komplexe C5H5M(CO)3-M(CO)2C5H5[N2 = CR1R2] (M = Mo: 9; M = W: 10) ergeben. Diazomalonsäure-diethylester (3k) wird im Zuge einer zur Koordinationsverbindung 14 führenden 1,1-Insertion in die polare Wolfram-Wasserstoff-Bindung von 2 als Imino-amido-Ligand komplexiert.
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  • 68
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 948-953 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, XXI. On Dehydro Amino Acids, VIII. N-Acyl-α,β-dehydro Amino Acids by Rearrangement of N-Acyl-α-imino AcidsAcetylation of 2-iminoisovaleric acid ester 1 gives the acetyl imino derivative 2. By addition of nucleophilic reagents the α-substituted valine esters 5 and 6 are obtained; base catalyzed rearrangement affords acetyl-α,β-dehydrovaline ester 7. The latter reaction opens a general approach to Boc-α,β-dehydroamino acids 11a-d and esters 9a-d.
    Notes: Durch Acetylierung von 2-Iminoisovaleriansäureester 1 wird die Acetyliminoverbindung 2 erhalten. Addition von nucleophilen Reagentien führt zu den α-substituierten Valinestern 5 und 6, basenkatalysierte Umlagerung zu Acetyl-α,β-dehydrovalinester 7. Letztere Reaktion eröffnet einen allgemeinen Weg zu Boc-α,β-Dehydroaminosäuren 11a-d und ihren Estern 9a-d.
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  • 69
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 979-984 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Natural Dibenzo-α-pyrones, II. Synthesis of Alternariol and Alternariol 9-Methyl EtherThe synthesis of 3,7,9-trihydroxy-1-methyl-6H-dibenzo[b,d]pyran-6-one (alternariol, 1) and the first synthesis of its 9-methyl ether (2) as well as an extension of the Hurtley condensation to o-bromobenzamides are reported.
    Notes: Die Synthese von 3,7,9-Trihydroxy-1-methyl-6H-dibenzo[b,d]pyran-6-on (Alternariol, 1), die erste Synthese von Alternariol-9-methylether (2) und eine Erweiterung der Hurtley-Kondensation auf o-Brombenzamide wird beschrieben.
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  • 70
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1020-1026 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbonylchlorobis(tri-tert-butylphosphine)rhodium(I)Tri-tert-butylphosphine reacts with tetracarbonyl-μ-dichlorodirhodium (1) to form carbonylchlorobis(tri-tert-butylphosphine)rhodium(I) (2), existing in an equilibrium with dicarbonyl-μ-dichlorobis(tri-tert-butylphosphine)dirhodium (3) in pentane solution, which can be seen in the i. r. and 31P-n. m. r. spectra. The crystal structure of 2 has been determined from single crystal X-ray data. The compound crystallizes with 4 molecules in a unit cell of symmetry P21/n in the monoclinic system.
    Notes: Tri-tert-butylphosphin reagiert mit Tetracarbonyl-μ-dichlorodirhodium (1) unter Bildung von Carbonylchlorobis(tri-tert-butylphosphin)rhodium(I) (2), das in Pentanlösung mit Dicarbonyl-μ-dichlorobis(tri-tert-butylphosphin)dirhodium (3) im Gleichgewicht steht, was sich im IR- und 31P-NMR-Spektrum verfolgen läßt. Die Kristallstruktur von 2 wurde röntgenographisch aus Diffraktometer-Einkristalldaten bestimmt. Die Verbindung kristallisiert mit 4 Molekülen in der Elementarzelle der Symmetrie P21/n im monoklinen System.
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  • 71
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1042-1046 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stable Mercury(I)-Sulfur Compounds, 3. Investigations on the Donor Capacity of Sulfur at the Mercury(I) IonNew mercury(I)-sulfur compounds have been prepared by reactions between mercury(I) nitrate, perchlorate or hexafluorosilicate solutions with methanol, water/benzene or water/methylene chloride solutions of the following sulfur donor ligands: 1,3-dithiolane, 2-phenyl-1,3-dithiolane, 2,2′-trimethylenebis(1,3-dithiolane), bis(benzylthio)methane, dibenzylsulfide. With mercury(I)-dinitrate, the products are the 1:1 adducts (1a), (4a), (6a), and (11a). With mercury(I)-perchlorate the 1:2 adducts (1b),(4b),(6b) or the 1:1 adducts (5b) and (11b) have been obtained. Dibenzylsulfide forms a 1:1 adduct (11c) with dimercury(I)-hexafluorosilicate.
    Notes: Neue Quecksilber(I)-Schwefel-Verbindungen wurden durch Umsetzung von Quecksilber(I)-nitrat, -perchlorat bzw. -hexafluorosilicat-Lösungen mit folgenden Schwefel-Donor-Liganden in methanolischen Lösungen bzw. im Zweiphasensystem wäßrige Lösung/Benzol oder Methylenchlorid hergestellt: 1,3-Dithiolan, 2-Phenyl-1,3-dithiolan, 2,2′-Trimethylenbis(1,3-dithiolan), Bis-(benzylthio)methan, Dibenzylsulfid. Mit Quecksilber(I)-nitrat werden 1:1-Addukte (1a), (4a), (6a) und (11a), mit Quecksilber(I)-perchlorat 1:2-Addukte (1b), (4b) und (6b) bzw. 1:1-Addukte (5b) und (11b) erhalten. Mit Diquecksilber(I)-hexafluorosilicat bildet das Dibenzylsulfid ein 1:1-Addukt (11c).
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  • 72
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1069-1085 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Reactions of Thiacyclanone-1,1-dioxides with DiazoalkanesThiacyclanone-1,1-dioxides 1a-e, 9, 13, 15a react with diazomethane and diazoethane to give the enol ethers 2a-j, epoxides 4c, h, 10a, 14a, 17a, α-alkyl-β-ketosulfones 3d, e, j, and ring-enlarged ketosulfones 5h, i, 7h, 11b, 12b, 15b, 16b and 18a, depending on the size of the ring and the position of the carbonyl and sulfonyl group to each other. The enol ethers are easily hydrolysed with mineral acids forming the β-ketosulfones 1a-e. In the presence of lewis acids ethyl diazoacetate yields ethoxycarbonylmethoxy compounds 2k, I, and ring-enlarged β-ketoesters 5k-o, 7m, n, 15c, 16c, and 18c. Only the γ-ketosulfone 9 with ethyl diazoacetate gives, in addition to the ring-enlarged product 11c, the glycidic ester 10c. The β-ketoesters undergo hydrolysis and decarboxylation to the ketosulfones in very good yield. In the ring-expansion of ketosulfones with diazoethane and ethyl diazoacetate the preferred insertion of the diazo compound occurs between the C-3 and C-4 atoms.
    Notes: In Abhängigkeit von der Ringgliederzahl und der Lage von Carbonyl- und Sulfonylgruppe zueinander reagieren Thiacyclanon-1,1-dioxide 1a-e, 9, 13 und 15a mit Diazomethan bzw. -ethan zu Enolethern 2a-j, Epoxiden 4c, h, 10a, 14a, 17a, α-Alkyl-β-ketosulfonen 3d, e,j oder zu ringerweiterten Ketosulfonen 5h,i, 7h, 11b, 12b, 15b, 16b und 18a. Die Enolether spalten leicht mit Mineralsäure zurück zu den β-Ketosulfonen 1a-e. Mit Diazoessigester in Gegenwart von Lewis-Säuren entstehen die Ethoxycarbonylmethoxy-Verbindungen 2k, I bzw. die ringerweiterten β-Ketoester 5k-o, 7 m, n, 15c, 16c und 18c; lediglich das γ-Ketosulfon 9 gibt mit Diazoessigester neben dem Ringerweiterungsprodukt 11c den Glycidester 10c. Die β-Ketoester lassen sich in guten Ausbeuten zu den Ketosulfonen verseifend decarboxylieren. Bei den Ringerweiterungen der Ketosulfone mit Diazoethan und Diazoessigester ist eine bevorzugte Insertion des Diazoalkanrestes zwischen C-3 und C-4 festzustellen.
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1124-1129 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Four- and Five-membered Phosphorus Heterocycles, 15. The Products of Carbohydrazide/Phosphonic Chloride Reaction: 2,2′-Spirobi(1,3,4,2λ5-oxadiaza-phospholines)The products of the 2:1-condensation of carbohydrazides 1 with phosphonic dichlorides 2 are not cyclic anhydrides 4 of the phosphonic bis(acylhydrazides), as has been assumed until now. Instead they possess the structure of the spirocyclic phosphoranes 9 named in the title. Their formation is due to the unusual reaction of a P = O-bond involving elimination of water. With dimethylphosphinic chloride (14) the hydrazides 1 react in quite the same sense to give the dimers 17 of oxadiazaphospholes in which the pentacoordinate phosphorus (as a bridgehead) is again part of two small rings. The phosphoranes 9 are also obtained from the reaction of 1 with tetrachloro-phosphoranes 5 or thiophosphonic dichlorides 18 or even bis(dimethylamino)phosphines 19.
    Notes: Die 2:1-Kondensationsprodukte aus Carbonsäurehydraziden 1 und Phosphonyldichloriden 2 stellen nicht - wie bisher angenommen - durch Anhydridbildung cyclisierte Phosphonsäure-bis(acylhydrazide) 4 dar, sondern die im Titel genannten spirocyclischen Phosphorane 9. Ihr Entstehen beinhaltet das „Aufrichten“ einer P = O-Bindung unter Wasserabspaltung. Mit Di-methylphosphinylchlorid (14) reagieren die Hydrazide 1 im gleichen Sinn zu Oxadiazaphosphol-Dimeren 17 mit ebenfalls bicyclisch (als Brückenkopf) eingebautem Phosphoranphosphor. Die Phosphorane 9 entstehen auch aus 1 und Tetrachlorphosphoranen 5 oder Thiophosphonyl-dichloriden 18 oder auch Bis(dimethylamino)phosphinen 19.
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1684-1690 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of Hydronium Tetrachloroaurate(III)-2,2-dimethyl-2H-benzimidazole 1,3-Dioxide, (C9H10N2O2)H3O+ [AuCl4]-1,2-Benzoquinone dioxime (1) reacts with tetrachlorogold(III) acid-trihydrate in dialkyl ketones as solvents to yield solids 5-7 which contain H3O+ and [AuCl4]- ions and neutral 2,2-dialkyl-2H-benzimidazole 1,3-dioxides (2-4). The organic, neutral molecule can easily be isolated from this solid by means of an ion-exchanger. The structure of hydronium tetrachloroaurat(III)-2,2-dimethyl-2H-benzimidazole 1,3-dioxide (5), which can be obtained from acetone solutions, is obtained by X-ray analysis.
    Notes: Die Reaktion von 1,2-Benzochinondioxim (1) mit Tetrachlorogold(III)-säure-trihydrat in Dialkyl-ketonen als Lösungsmittel führt zu Festkörpern 5-7, die aus H3O+- und [AuCl4]--Ionen sowie aus neutralen 2,2-Dialkyl-2H-benzimidazol-1,3-dioxiden (2-4) aufgebaut sind. Daraus läßt sich das organische neutrale Molekül mittels eines Ionenaustauschers abtrennen und in Substanz isolieren. Die Struktur des aus Aceton erhältlichen Hydronium-tetrachloroaurat(III)-2,2-dimethyl-2H-benzimidazol-1,3-dioxids (5) wird durch Röntgenstrukturanalyse ermittelt.
    Additional Material: 1 Ill.
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  • 75
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1744-1747 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Photochemistry of Two Tribenzo-(CH)12-Valence IsomersA new synthesis of the tribenzo[12]annulene 1 and the photochemical transformations of 1 and of its valence isomer 2 are described. A reaction mechanism is proposed.
    Notes: Eine neue Synthese des Tribenzo[12]annulens 1 und die photochemischen Umwandlungen von 1 und seines Valenzisomeren 2 werden beschrieben. Ein Reaktionsmechanismus wird vorgeschlagen.
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  • 76
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1759-1762 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, 94. New Furanoeremophilanes from Ligularia vorobierii Worosh.L. vorobierii contains besides already known five new furanoeremophilane derivatives (5 and 7-10). Their structures have been elucidated by spectroscopic methods. The constituents show again a close relationship to the neighbouring genus Senecio.
    Notes: L. vorobierii enthält neben bereits bekannten fünf neue Furanoeremophilan-Derivate (5 und 7-10), deren Konstitutionen durch spektroskopische Methoden geklärt werden. Die Inhaltsstoffe zeigen erneut eine enge Verwandtschaft zu der Nachbargattung Senecio.
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  • 77
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on the Reactivity of Metal π-Complexes, XXII. Sandwich-like Dinuclear (Pd-Pd)-Complexes with Bridging Cyclopentadienyl and Allyl LigandsThe reaction of C5H5Pd(2-RC3H4) (2-RC3H4 = 2-R-allyl) with tertiary phosphines or phosphites in the molar ratio of 1:1 produces in practically quantitative yields the dinuclear complexes (C5H5)(2-RC3H4)Pd2L2 (4-20) in which palladium has the oxidation state +1. The crystal structure analysis of 5 (R = CH3, L = P(C6H5)3) and 12 (R = CH3, L = P(OC6H4-o-CH3)3) shows that the cyclopentadienyl as well as the allyl ligand is bonded in a sandwich manner to the Pd-Pd unit. The Pd-Pd distance of 267.9 (in 5) or 268.9 pm (in 12) is suggestive of a metal-metal bond. It is not possible to determine whether the cyclopentadienyl ring in 4-20 exists as a pentahapto- or trihapto-bonded ligand on the basis of the 1H- and 13C n. m. r. data. The reactivity of the dinuclear complexes is in agreement with square planar coordination of the metal atoms.
    Notes: Bei den Reaktionen von C5H5Pd(2-RC3H4) (2-RC3H4 = 2-R-Allyl) mit tertiären Phosphinen oder Phosphiten im Molverhältnis 1:1 entstehen in praktisch quantitativer Ausbeute die Zweikernkomplexe (C5H5)(2-RC3H4)Pd2L2 (4-20), in denen Palladium in der Oxidationszahl +1 vorliegt. Wie die Kristallstrukturanalysen von 5 (R = CH3, L = P(C6H5)3) und 12 (R = CH3, L = P(OC6H4-o-CH3)3) zeigen, sind sowohl der Cyclopentadienyl- als auch der Allyl-Ligand sandwichartig an die Pd2-Einheit gebunden. Der Pd-Pd-Abstand von 267.9 (in 5) bzw. 268.9 pm (in 12) weist auf das Vorliegen einer Metall-Metall-Bindung hin. Aufgrund der 1H- und 13C-NMR-Daten ist nicht zu entscheiden, ob in 4-20 der Cyclopentadienylring als pentahapto-oder trihapto-gebundener Ligand vorliegt. Die Reaktivität der Zweikernkomplexe steht mit einer quadratisch-planaren Koordination der Metallatome in Einklang.
    Additional Material: 3 Ill.
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  • 78
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1833-1851 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Double Metallation of Benzyl- and Allylmercaptanes; the Thiobenzaldehyde and Thioacrolein DianionsDouble deprotonation of benzyl, allyl and 2-methylallyl mercaptane furnishes thiocarbonyl dianiones 2, 12, and 15, respectively. The novel nucleophiles react with alkyl halides, epoxides, and carbonyl derivatives to give good yields of products of type 3, 13/14, and 16/17, respectively. The doubly lithiated allyl mercaptanes are preferentially attacked by all of the employed electro-philes in the γ-position (60/40-90/10 γ/α-ratio) to lead to cis-vinyl sulfides 13 and 16. These can be converted into sulfur-free propanal derivatives 22-26 in high yields. 12 resembles synthetically the otherwise not available 3-lithiopropionaldehyde (18′, homoenolate).
    Notes: Thiocarbonyl-Dianionen lassen sich quantitativ durch doppelte Deprotonierung aus Benzyl-(→2), Allyl- (→12) und 2-Methylallylmercaptan (→15) erzeugen. Die neuen Nucleophile setzen sich mit Alkylhalogeniden, Epoxiden und Carbonylverbindungen in guten Ausbeuten zu Produkten vom Typ 3, 13/14 bzw. 16/17 um. Die doppelt metallierten Allylmercaptane reagieren mit allen bisher getesteten Elektrophilen bevorzugt in γ-Stellung (60/40—90/10 für γ/α) zu cis-Vinyl-sulfiden 13 und 16, die in guten Ausbeuten in schwefelfreie Propionaldehydderivate 22-26 übergefuhrt werden konnten. 12 entspricht damit synthetisch dem nicht direkt zugänglichen 3-Lithio-propionaldehyd (18′, Homoenolat).
    Additional Material: 4 Tab.
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  • 79
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1896-1907 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Branched-chain Sugars, XV. Glycoside Syntheses with L-StreptoseThe halogeno derivatives of the cyclic carbonates 11 a and 11 b are most suitably used in the synthesis of L-streptose β-glycosides. α-Glycosides are obtained from the benzylidene compound 20. The benzylidene group can be subsequently removed by catalytic hydrogenation. Using the glycosyl halide 16 a also α-glycosides are formed in high yields. However, it is difficult to cleave the isopropylidene group under acidic conditions. Acetylated halides of type 4 are very labile and therefore not useful in glycoside synthesis.
    Notes: Zur Herstellung β-L-glycosidischer Verknüpfungen der L-Streptose sind die Halogenide des cyclischen Carbonats 11 a und 11 b am besten geeignet. α-L-Glycosidische Verknüpfungen der L-Streptose werden am günstigsten mit der Benzylidenverbindung 20 erhalten. Die Benzylidengruppe ist anschließend hydrogenolytisch abspaltbar. Auch das Halogenid 16 a liefert hohe Anteile an α-Glycosid. Die Isopropylidengruppe ist aber schwierig sauer abspaltbar. Acetylierte Halogenide wie 4 sind wegen ihrer Empfindlichkeit zur Glycosidsynthese weniger geeignet.
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  • 80
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1925-1930 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Building Units for Oligosaccharides, VI. Synthesis of StreptobiosamineA synthesis of 5-deoxy-2-O-(2-deoxy-2-methylamino-α-D-glucopyranosyl)-3-C-formyl-D-lyxofuranose (11) (D-streptobiosamine) is described. The same synthesis was repeated with the corresponding L-sugars. It leads to 5-deoxy-2-O-(2-deoxy-2-methylamino-α-L-glucopyranosyl)-3-C-formyl-L-lyxofuranose (1) (L-streptobiosamine), the disaccharide portion of streptomycin.
    Notes: Eine Synthese der 5-Desoxy-2-O-(2-desoxy-2-methylamino-α-D-glucopyranosyl)-3-C-formyl-D-lyxofuranose (11) (D-Streptobiosamin) wird beschrieben. Die gleiche Synthese wurde auch mit den entsprechenden L-Zuckern durchgeführt. Sie lieferte 5-Desoxy-2-O-(2-desoxy-2-methylamino-α-L-glucopyranosyl)-3-C-formyl-L-lyxofuranose (1) (L-Streptobiosamin), das den Disaccharidbaustein des Streptomycins darstellt.
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  • 81
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1971-1977 
    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, XIV. The Catalysed Reaction of Aldehydes with Mannich BasesAlkali cyanide- and thiazolium salt-catalysed addition of aldehydes to Mannich bases of saturated and unsaturated ketones leads to the formation of 1,4-diketones (1-6, 9-22).
    Notes: Alkalicyanid- und thiazoliumsalz-katalysierte Additionen von Aldehyden an Mannich-Basen von gesättigten und ungesättigten Ketonen führen zu 1,4-Diketonen (1-6, 9-22).
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  • 82
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mechanism of the Aluminium Chloride-catalysed Rearrangement of 7 H-Dibenzo[c,g]carbazole to 7 H-Dibenzo[a,g]carbazole and of Related Aromatic Skeleton RearrangementsOn an experimental basis a mechanism for the aluminium chloride-catalysed rearrangement of 7 H-dibenzo[c,g]carbazole (1) to 7 H-dibenzo[a,g]carbazole (2) is derived, that involves in the first step formation of the 5,6-dihydro derivatives 3 and 9 which rearrange via a spiro cation 14. This mechanism should also be valid for topologically analogous systems.
    Notes: Für die aluminiumchlorid-katalysierte Skelettumlagerung von 7 H-Dibenzo[c,g]carbazol (1) in 7 H-Dibenzo[a,g]carbazol (2) wird aus Experimenten ein Mechanismus abgeleitet, nach dem zunächst Bildung der 5,6-Dihydro-Derivate 3 und 9 erfolgt, die über ein Spirokation 14 umlagern. Dieser Mechanismus sollte auch für topologisch analoge Systeme zutreffen.
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  • 83
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2019-2027 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclophosphates, III. Synthesis and Properties of Uridine 3′,5′-Cyclophosphate EstersThe uridine 3L′,5′-cyclophosphate esters 4-11 were synthesized by reaction of the free acid of uridine 3′,5′-cyclophosphate (1-3) with the appropriate diazoalkane. The configuration of the isomeric 1,3,2λ5-dioxaphosphorinanes is assigned on the basis of an X-ray analysis with the aid of 31P n. m. r. The stereoselectivity was influenced in part by the degree of reactivity of the diazo compound, by steric hindrance in the 2′-position of the ribose, and by variation in the reaction temperature. The newly synthesized compounds were characterized by u. v. and 31P n. m. r. spectra.
    Notes: Die Uridin-3′,5′-cyclophosphat-ester 4-11 wurden durch Reaktion der freien Säure des Uridin-3′,5′-cyclophosphates (1-3) mit den entsprechenden Diazoalkanen erhalten. Die Zuordnung der stereoisomeren 1,3,2λ5-Dioxaphosphorinane läßt sich mit Hilfe der 31P-NMR-Spektren aufgrund einer Röntgenstrukturanalyse zeigen. Eine stereoselektive Beeinflussung durch Variation der Reaktivität der Diazokomponente oder durch sterische Hinderung an der 2′-Position der Ribose, sowie in Abhängigkeit von der Temperatur, konnte partiell erzielt werden. Sämtliche synthetisierten Verbindungen wurden durch UV- und 31P-NMR-Spektren charakterisiert.
    Additional Material: 4 Tab.
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  • 84
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1462-1469 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mannich Reaction at 2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one, the Chromophore of the Ribonucleoside “Q”2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one (6a) reacts with dimethylamine and cyclopentylamine in the presence of formaldehyde to form the Mannich bases 6c and d. From 6c the amine moiety was split off on hydrogenation under pressure. The degradation product was identical with 2-amino-6-methyl-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one (6b), which was obtained by unambiguous synthesis. This shows that in contrast to 3,7-dihydropyrrolo[2,3-d]-pyrimidin-4-one, Mannich reaction involving 6a leads to substitution at C-6.
    Notes: 2-Amino-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-on (6a) reagiert mit Dimethylamin und Cyclo-pentylamin in Gegenwart von Formaldehyd zu den Mannich-Basen 6c und d. Aus 6c ließ sich durch Druckhydrierung das Amin abspalten. Das Abbauprodukt war identisch mit 2-Amino-6-methyl-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-on (6b), das auf eindeutigem Syntheseweg erhalten worden war. Damit wird gezeigt, daß die Mannich-Reaktion bei 6a im Gegensatz zu 3,7-Dihydropyrrolo[2,3-d]pyrimidin-4-on zur Substitution an C-6 führt.
    Additional Material: 1 Ill.
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  • 85
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1492-1496 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: as-Triazines and Condensed Derivatives, XVIII. Ring-Chain Tautomerism in 3-Hydroxythiazolo[3,2-b]-as-triazin-7-onesThe hydroxyl groups of the most stable conformer (y) of 3-hydroxythiazolo[3,2-b]-as-triazin-7-one (2a) as well as of the related compound 4 are axial.  -  At elevated temperatures, the AB signal of the CH2 group in the 1H-NMR spectrum of compound 2b collapses, as a result of tautomerization to 3b, into a singlet. ΔG≠ is 17.0 kcal/mole at the coalescence temperature (68°C). In agreement with the decreasing order of the +I effect in the series CH3 〉 CH2Cl 〉 H, no similar tautomerizations take place up to 130°C in the case of compounds 2a and 2c. Compound 4, however, exists at elevated temperatures as an equilibrium mixture with the corresponding “open-chain” form 5.  -  The singlet of the CH2Cl group of compound 2c is transformed, at elevated temperatures, into an AB quadruplet. An explanation for this apparent anomaly is suggested.
    Notes: Das stabilste Konformere (y) des 3-Hydroxythiazolo[3,2-b]-as-triazin-7-ons (2a) enthält eine axiale OH-Gruppe, ebenso wie das der verwandten Verbindung 4.  -  Bei Erhöhung der Temperatur fällt das AB-Signal der CH2-Gruppe im 1H-NMR-Spektrum von 2b als Folge der Tautomerisierung zu 3b in ein Singulett zusammen. Der ΔG≠-Wert bei der Koaleszenztemperatur (68°C) beträgt 17.0 kcal/mol. Im Einklang mit der Abnahme des +I-Effektes in der Reihenfolge CH3 〉 CH2Cl 〉 H erfolgt bei den Verbindungen 2a und 2c bis 130°C keine ähnliche Tautomerisierung. Die Verbindung 4 liegt jedoch bei erhöhter Temperatur im Gleichgewicht mit der „offenkettigen“ Form 5 vor.  -  Bei steigender Temperatur wandelt sich das Singulett der CH2Cl-Gruppe von 2c in ein Quadruplett um. Eine Erklärung für diese scheinbare Anomalie wird gegeben.
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  • 86
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Seven-Membered Ring Systems, XV. Organolithium Derivatives of the Conformationally Rigid Tetraphenyltribenzocycloheptariene (1,2,3,4-Tetraphenyl-9H-tribenzo[a,c,e]cycloheptene)Quasi-axial substituents (e. g. hydrogen and chlorine) at C-9 of 1,2,3,4-tetraphenyl-9H-tribenzo-[a,c,e]cycloheptene (1) are easily exchanged with formation of quasi-axial organometallic compounds. Only in the case of the 9-lithio-9-methyl derivative 17 an equilibrium 17A ⇄ 17B between a quasi-equatorial and a quasi-axial lithium compound was found. Various stereospecific reactions of the new organometallics are reported and the reactivity differences of conformational origin are discussed.
    Notes: Quasi-axiale Substituenten (z. B. Wasserstoff und Chlor) am C-9 von 1,2,3,4-Tetraphenyl-9H-tribenzo[a,c,e]cyclohepten (1) werden leicht unter Bildung quasi-axialer Organometall-Verbindungen ausgetauscht. Lediglich im Fall des 9-Lithio-9-methyl-Derivates 17 konnte ein Gleichgewicht 17A ⇄ 17B zwischen einer quasi-äquatorialen und einer quasi-axialen Lithium-Verbindung nachgewiesen werden. Zahlreiche stereospezifisch verlaufende Abwandlungen der neuen Organometalle werden beschrieben und die konformativ bedingten Reaktivitätsunterschiede diskutiert.
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  • 87
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1576-1585 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1-Methyl-1-methylene-1λ5-phosphorinane and Cyclopropyl(dimethyl)methylenephosphorane: Two Different Types of Ylides from an Analogous Reaction, and their ComplexesThe reaction of NaNH2 with (4-bromobutyl)- or (3-bromopropyl)-trimethylphosphonium bromide in THF under reflux yields the two title compounds 1 and 8, resp. At room temperature imide-bridged double ylides 2 and 10 are generated. The reaction path is interpreted. With copper, silver, and gold(I) chloride, the dimeric coinage metal complexes of these ylides are obtained. In the first case (with 1) the complexes are assigned a double spirocyclic structure (7a-c).
    Notes: Die Reaktion von NaNH2 mit (4-Brombutyl)- oder (3-Brompropyl)-trimethylphosphonium-bromid in siedendem THF liefert die beiden Titelverbindungen 1 bzw. 8. Bei Raumtemperatur entstehen imid-verbrückte Doppel-Ylide 2 bzw. 10. Der Reaktionsverlauf wird gedeutet. Mit Kupfer-, Silber- und Gold(I)-chlorid werden die dimeren Münzmetall-Komplexe der Ylide erhalten, denen im ersteren Fall (mit 1) eine doppelt spirocyclische Struktur zukommt (7a-c).
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1597-1600 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 89
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 820-832 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of Heterocumulenes, IX. 1:1-, 2:1-, and 3:1-Adducts from the Reaction of Isothiocyanates with 3-Dimethylamino-2,2-dimethyl-2H-azirineTreatment of the azirine 1 with the activated isothiocyanates 2a, b leads to 1,3-cleavage of the ring and formation of the dipoles 5, which can be characterized by hydrolysis, protonation and methylation to give 6-8. In the reaction of 1 with the sterically hindered alkyl isothiocyanates 2f-i the ring of 5 is split to form the carbodiimides 10. 10f-i hydrolyze via 5 to give the thioureas 11, from which 11f, g easily cyclize to yield the 2-thiohydantoins 12. Cycloaddition reactions of 10f lead to the heterocycles 14, 15, and 17. The alkyl isothiocyanates 2c-e react with 1, depending on the reaction conditions, to give the 3:1-adducts 14 or the dipolar 2:1-adducts 21. The hydrolysis of 21e leads to the thiazolinone 26 with the acyclic product 25 as intermediate.
    Notes: Die aktivierten Isothiocyanate 2a, b reagieren mit dem Azirin 1 unter öffnung der 1,3-Bindung zu den Dipolen 5, die sich durch Hydrolyse, Protonierung und Methylierung zu 6-8 charakterisieren lassen. Im Falle der sterisch gehinderten Alkylisothiocyanate 2f-i tritt Ringöffnung von 5 zu Carbodiimiden 10 ein. 10f-i hydrolysieren über 5 zu den Thioharnstoffen 11, die für 11f, g leicht zu den 2-Thiohydantoinen 12 cyclisieren. Cycloadditionsreaktionen mit 10f führen zu den Heterocyclen 14, 15 und 17. Die Alkylisothiocyanate 2c-e bilden mit 1 je nach den Reaktionsbedingungen die 3:1-Addukte 14 oder die dipolaren 2:1-Addukte 21. Die Hydrolyse von 21e führt über das ringoffene Produkt 25 zum Thiazolinon 26.
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  • 90
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    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 852-866 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Generation of and Olefination with α-S-, -Se-, -Si-, and -Sn-perheterosubstituted (Trimethylsilyl)-methyllithium DerivativesThe Peterson-olefination reaction of equation (1) is used to prepare ketenedithio- 5, ketenediseleno acetals 8, trimethylsilyl- 11, 1,1-bis(trimethylsilyl)- 12, 1-alkylthio- and 1-arylthio-1-silyl- 16, as well as 1-alkylthio- and 1-arylthio-1-stannyl olefins 19 from the α-silyllithium compounds 4, 7b, 9, 10, 15, and 18, respectively. New or improved productive methods of generation of these olefinating reagents are described. The scope and limitations of the present olefinations are discussed.
    Notes: Mit der Peterson-Olefinierungsreaktion der Gl. (1) werden aus den α-Silyllithium-Verbindungen 4, 7b, 9, 10, 15 und 18 Ketendithio- 5 bzw. Ketendiselenoacetale 8, Trimethylsilyl- 11, 1,1-Bis(trimethylsilyl)- 12, 1-Alkylthio- und 1-Arylthio-1-silyl- 16, sowie 1-Alkylthio- und 1-Arylthio-1-stannylolefine 19 hergestellt. Für die Olefinierungsreagentien 7b, 9, 10, 15 und 18 werden neue oder verbesserte, ergiebige Erzeugungsmethoden beschrieben. Die Grenzen der Anwendbarkeit der Olefinierungsreaktionen werden diskutiert.
    Additional Material: 5 Tab.
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  • 91
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 921-941 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, XVII. On Dehydroamino Acids, IV. Ring Closure of DehydropeptidesSix- or five-membered cyclic compounds (amino-piperazinediones: 2, 14-19, 21, 24, or imidazolidinones 28, 29) are obtained under basic conditions from dehydropeptides by α-addition of an amide function to the acylaminoacrylic unit. Sterical conditions, scope, and limitations of this cyclisation have been investigated up to the dehydrotetrapeptide amide 20. Formation of six-membered rings is preferred. Five-membered rings only result, if reaction to six-membered rings is excluded either by the structure of the dehydropeptide (no NH-function available) or by its conformation (s-trans amide function). Ring closure to the cyclodipeptides 2a, 14, 15, 18, 19, 21, and 24 proceeds stereoselectively.
    Notes: Dehydropeptide bilden in alkalischer Lösung durch α-Addition einer Amidgruppe an das Acylaminoacrylsäuresystem sechs- oder fünfgliedrige Ringe (Amino-piperazindione: 2, 14-19, 21, 24 bzw. Imidazolidinone: 28, 29). Reaktionsbedingungen, räumlicher Ablauf und Grenzen der Cyclisierung wurden bis zum Ringschluß des Dehydrotetrapeptidamids 20 untersucht. Der Sechsring wird bevorzugt. Ein Fünfring bildet sich nur dann, wenn die Cycloaddition zum Sechsring infolge der Struktur (keine NH-Funktion zur Addition) oder der Konformation (s-trans-Fixierung einer Amidbindung) des Dehydropeptids nicht möglich ist. Der Ringschluß zu den Cyclodipeptiden 2a, 14, 15, 18, 19, 21 und 24 verläuft stereoselektiv.
    Additional Material: 2 Tab.
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  • 92
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 965-978 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dyotropic Rearrangements, XI. Mechanism of the Thermal Rearrangement of Allyl (Silymethyl) EthersThe study of the mechanism of the thermal rearrangement of allyl (silylmethyl) ethers 1a-e has been extended to include crossover and trapping experiments, secondary kinetic deuterium isotope effects, solvent influence and an investigation of the stereochemistry of the migrating silyl group. The rate determining step appears to be the coordination between the silyl group and the oxygen atom, causing the allyl-α-C-O bond to be loosened. In the following, kinetically not measurable step the allyl groups either migrate concertedly with allyl inversion or split off into radicals, depending upon the nature of the substituents R1,R2.
    Notes: Die Studie über den Mechanismus der thermischen Umlagerung von Allyl-(silymethyl)-ethern 1a-e wird mit Hilfe von Kreuzungs- und Abfangsversuchen, sekundären kinetischen Deuterium-Isotopeneffekten, Löungsmitteleinflüssen und einer Untersuchung zur Stereochemie der wandernden Silylgruppe vertieft. Danach scheint der geschwindigkeitsbestimmende Schritt die Koordinierung zwischen dem Silylrest und dem Sauerstoff zu sein, die eine Lockerung der Allyl-α-C-O-Bindung bewirkt. Im anschließenden, kinetisch nicht faßbaren Schritt lagern die Allylgruppen entweder konzertiert mit Allylumkehrung um oder zerfallen in Radikale, je nach Natur der Substituenten R1, R2.
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  • 93
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2180-2188 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition of 2-Diazopropane to Allene. Asymmetric Destruction of 1-Pyrazolines with Circularly Polarized Light1,3-Dipolar cycloaddition of 2-diazopropane to allene leads to 1 and the spiropyrazoline 2. The thermal and photochemical decomposition reactions of 1 and 2 are investigated. Irradiation of 2 with circularly polarized light produces a sample which displays optical acitivity and has a strong Cotton effect in the CD. The possibility of applying circularly polarized light for the solution of mechanistic problems in the decomposition of 1-pyrazolines is discussed.
    Notes: Die 1,3-dipolare Cycloaddition von 2-Diazopropan an Allen liefert 1 und das Spiropyrazolin 2, deren thermische und photochemische Zersetzungsreaktionen untersucht werden. Die Bestrahlung von 2 mit circular polarisiertem Licht ergibt eine Anreicherung von optisch aktivem 2, das einen starken Cotton-Effekt im CD zeigt. Die Möglichkeit der Anwendung von circular polarisiertem Licht zur Lösung mechanistischer Fragen beim Zerfall von 1-Pyrazolinen wird diskutiert.
    Additional Material: 1 Ill.
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  • 94
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2222-2235 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Functional Derivatives of Trimethylphosphine, IV. Hydrido(phosphine)iron(II) ComplexesTetrakis(trimethylphosphine)iron, L4Fe (L = P(CH3)3) (3), reacts with HCl to give L2FeCl2 (1a). As an intermediate of this reaction covalent L4(H)FeCl (4a) can be isolated. Its formation by cleavage of the Fe—C bond in L3(H)[(CH3)2PCH2]Fe which is in equilibrium with 3 is established with DCl. With HX (H = NH4⊕, (CH3)3PH⊕; X = Cl⊖, Br⊖, I⊖, PF6⊖) as reagents, L4(H)FeX (X = Cl, Br, I) (4a-c) and [L5(H)Fe]⊕X⊖ (X = Cl, Br, I, PF6) (6a-d) are prepared or their formation in solution is proved. In these solutions two further species, [L4(H)Fe]⊕[X ⊖ solvent]⊕ and [L4(H)(solvent)Fe]⊖ X⊖, are characterized by spectroscopy. Substitution reactions using P(OCH3)3, CO, or isoprene yield the complexes [L5-nL′n(H)Fe]⊕PF⊖ (n = 1. L′ = CO; n = 2, L′ = CO, P(OCH3)3, ½ isoprene; n = 3, L′ = P(OCH3)3), which are also obtained by the direct reaction of the iron(0) complexes L5-nL′nFe with NH4PF6. The isoprene substituted hydridoiron complex (8c) is found to be in an equilibrium with its π-allyl form. As starting materials the tetrahedral complexes L2FeX2 (L = Cl, Br, I) (1a-c) and octahedral L4FeI2 (2c) are characterized.
    Notes: Tetrakis(trimethylphosphin)eisen, L4Fe (L = P(CH3)3) (3), reagiert mit HCl zu L2FeCl2 (1a). Dabei läßt sich kovalentes L4(H)FeCl (4a) als Zwischenstufe fassen, dessen Bildung durch Fe—C-Bindungsspaltung des mit 3 im Gleichgewicht stehenden L3(H)[(CH3)2PCH2]Fe mit DCl nachgewiesen wird. Mit HX (H = NH4⊕. (CH3)3PH⊕; X = Cl⊖, Br⊖, I⊖, PF6⊖) werden L4(H)FeX (X = Cl, Br, I)(4a-c) und [L5(H)Fe]⊕X⊖ (X = Cl, Br, I, PF6) (6a-d) dargestellt bzw. ihre Bildung in Lösung nachgewiesen. In diesen Lösungen werden daneben [L4(H)Fe]⊕[X · Solvens]⊖ und [L4(H)(Solvens)Fe]⊕ X⊖ spektroskopisch charakterisiert. Substitutionsreaktionen mit P(OCH3)3, CO oder Isopren führen zu der Komplexreihe [L5-nL′n(H)Fe]⊕ PF6⊖ (n = 1. L′ = CO; n = 2. L′ = CO, P(OCH3)3, ½ Isopren; n = 3. L′ = P(OCH3)3). Diese Komplexe werden auch durch direkte Reaktion der Eisen(0)-Komplexe L5-nL′nFe mit NH4PF6 erhalten, wobei der isoprensubstituierte Hydridoeisenkomplex (8c) ein Gleichgewicht mit einer π-Allylform erkennen läßt Als Ausgangskomplexe werden die tetraedrischen L2FeX2-Komplexe (X = Cl, Br, I) (1a-c) sowie L4FeI2 (2c) charakterisiert.
    Additional Material: 3 Ill.
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  • 95
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2254-2275 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Verdazyls, 25. N-1′-Linked Bisverdazyls with Phenylene and Naphthylene Bridges, Thermochromism and Magnetic PropertiesThe synthesis of the bisverdazyls 1a-14a starts either from a monoverdazyl and uses 1-cyano-1-methylethyl as protecting group for the free valence (1 a) or from the corresponding bisformazans. 1a with the 1,4-phenylene bridge is diamagnetic up to 300 K, J 〉 3000 cal/mol. In 6a, 2a, and 7a the thermally populated triplet state is separated from the singlet ground state by 1500, 600, or 400 cal/mol. 3a-5a and 10a-13a have almost degenerate singlet triplet states. The magnetic properties, the zero field parameters D, and the thermochromic effects of the absorption spectra are discussed with respect to the structure of 1a-14a and the distorsion around the bridge axis.
    Notes: Die Darstellung der Bisverdazyle 1a-14a entweder stufenweise aus einem Monoverdazyl unter Verwendung der 1-Cyan-1-methylethyl-Gruppe als Schutzfunktion der freien Valenz (1a) oder aus den entsprechenden Bisformazanen wird beschrieben. 1a mit der 1,4-Phenylenbrücke liegt bis 300 K diamagnetisch vor, J 〉 3000 cal/mol. In 6a, 2a und 7a ist der thermisch besetzte Triplett-zustand vom Singulett-Grundzustand durch 1500, 600 bzw. 400 cal/mol getrennt. 3a-5a und 10a-13a besitzen praktisch entartete Singulett-Triplett-Zustände. Die magnetischen Eigenschaften. die Nullfeldparameter D und die Thermochromie-Erscheinungen der Absorptions-spektren werden im Zusammenhang mit der Struktur von 1a-14a und der Verdrillung um die Brückenachse diskutiert.
    Additional Material: 6 Ill.
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  • 96
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2368-2373 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition Reaction of N,N-Dialkylsulfamides, Tertiary Amines, and Phosphines with Fluorosulfonyl IsocyanateFluorosulfonyl isocyanate (2) reacts with N,N-dialkylsulfamides 1a-c or amidosulfonic methyl ester (1d) to afford the N-fluorosulfonyl-N′-(dialkylsulfamoyl)ureas 3a-d. Thermal decomposition of 3a-c leads to the formation of sulfamidie fluorides 4a-c. With tertiary amines and phosphines fluorosulfonyl isocyanate forms 1:1 adducts. Their structure can be proved by i. r. and 13C n. m. r. analysis.
    Notes: Durch Umsetzung von Fluorsulfonylisocyanat (2) mit N,N-Dialkylsulfamiden 1a-c bzw. Amidosulfonsäure-methylester (1d) werden N-Fluorsulfonyl-N′-(dialkylsulfamoyl)harnstoffe 3a-d erhalten, die beim Erhitzen leicht in die Sulfamidsäurefluoride 4a-c zerfallen. Mit tertiären Aminen und Phosphinen bildet Fluorsulfonylisocyanat 1:1-Addukte, deren Struktur durch IR- und 13C-NMR-Untersuchungen aufgeklärt wird.
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  • 97
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 2385-2387 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 98
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. XXVII 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1206-1215 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organometallic Lewis Bases, XXV. Phosphine Reactions of Heterodinuclear Complexes with Fe — Mo and Fe — W BondsThe complexes (CO)4Fe[μ-As(CH3)2]M(CO)2C5H5 (M = Mo, W) react with phosphines to form three different product types. These result from CO substitution on the iron atom, from cleavage of the metal-metal bond, or from a combination of both reactions. Investigations on the course of the reactions and independent syntheses of the products are reported.
    Notes: Die Komplexe (CO)4Fe[μ-As(CH3)2]M(CO)2C5H5 (M = Mo, W) reagieren mit Phosphinen zu drei verschiedenen Produkttypen. Diese resultieren aus einer CO-Substitution am Eisenatom, aus einer öffnung der Metall-Metall-Bindung oder aus einer Kombination beider Reaktionen. Untersuchungen zum Reaktionsverlauf und unabhängige Synthesen der Produkte werden beschrieben.
    Additional Material: 4 Tab.
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  • 100
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1246-1253 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Rotational Isomerism of Biisopropyl 1H N. M. R. Spectroscopic Investigation of 1,1,1,4,4,4-Hexadeuterio-2,3-bis(trideuteriomethyl)butaneThe conformational equilibrium in liquid biisopropyl was investigated by measuring the temperature-dependence of the vicinal coupling constant between the methine protons in 2,3-di[D3]-methyl-[1,1,1,4,4,4-D6]butane (3a) as a model compound. The change of 〈3 JHH〉 as a function of temperature shows a small stabilization of the gauche-conformer compared to the anti-conformer, which was found to be ca. 85 cal/mol by using 1H n. m. r. parameters for the pure conformers and various Karplus equations. The change of the relative stabilities of the rotamers by going from the gaseous to the liquid phase is explained on the basis of intermolecular dipolar interactions in the liquid state. The small difference in energy between the two conformers is discussed in comparison to bicyclopropyl, n-butane, and 2-methylbutane.
    Notes: Zur Untersuchung des Konformerengleichgewichtes im flüssigen Biisopropyl wurde die Temperaturabhängigkeit der vicinalen Kopplungskonstante zwischen den Methinprotonen an 2,3-Di[D3]-methyl-[1,1,1,4,4,4-D6]butan (3a) als Modellverbindung gemessen. Der Temperaturverlauf von 〈3 JHH〉 zeigt eine geringe Stabilisierung der gauche- gegenüber der anti-Form, die unter Verwendung verschiedener aus Karplus-Gleichungen ermittelter Endparameter zu ca. 85 cal/mol bestimmt wurde. Die Umkehrung der relativen Stabilität der Konformeren beim übergang von der Gasphase zur Flüssigkeit wird durch intermolekulare Dipol-Wechselwirkungen in der Flüssigkeit erklärt. Die annähernde Energiegleichheit der beiden Rotameren wird mit dem Verhalten von Bicyclopropyl, n-Butan und 2-Methylbutan verglichen.
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