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  • 1970-1974  (7,574)
  • Inorganic Chemistry  (3,865)
  • Industrial Chemistry  (1,865)
  • Chemical Engineering  (1,794)
  • Nuclear reactions
  • pharmacokinetics
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 407-414 
    ISSN: 1432-1041
    Keywords: Diuretic ; indapamide ; human pharmacology ; toxicology ; pharmacokinetics ; TLC assay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacology, toxicology and kinetics of a new diuretic indapamide, have been studied in six normal volunteers following a single oral dose of 40 mg. Pronounced diuresis was found, commencing three hours after ingestion, with a peak urinary flow at four to six hours, and continuing for a total of thirty-six hours. A fall in systolic standing blood pressure occurred twenty four hours after ingestion, coincident with the period of maximum dehydration. Free water clearance rose, accompanied by increased urinary losses of Na+, K+ and Cl− and alkalinisation of the urine comparable to the actions of benzothiadiazines. Total urinary losses of Ca2+, Mg2+ and PO 4 3− rose in spite of a fall in urinary concentrations of these ions. The Ca2+ effect compares with the acute ionic effects of other diuretics. No renal, hepatic or haematological toxic effect was demonstrated. The blood sugar level was not disturbed. Serum uric acid rose to abnormal levels although the change did not reach statistical significance. — A thin layer chromatographic method, with a sensitivity limit of 0.1 µg/ml., has been developed for the assay of indapamide in urine. The urinary excretion rates of the volunteers measured over forty-eight hours indicate that the drug is rapidly absorbed with a peak excretion, 2.9±1.3 µg/min occurring three hours after ingestion. The drug is eliminated bi-phasically with an initial short rapid elimination followed by a slower exponential decline with a mean elimination half-life of 10.3 ± 3.9 h. The mean urinary excretion of unchanged indapamide over forty-eight hours was 4.4±1.4% of the administered dose. — It is concluded that indapamide is an effective long-acting diuretic with comparable action to the benzothiadiazine diuretics, but without an effect on blood sugar level in single doses in normal subjects. In contrast with other diuretics, indapamide appears to be extensively metabolised in man, and its longer duration of action to be related to a longer elimination half-life.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1041
    Keywords: Oral antidiabetic drug ; butylbiguanide ; pharmacokinetics ; two-compartment open model ; plasma concentration ; liver concentration ; intestine concentration ; man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary 50 mg14C-Butylbiguanide was administered intravenously to 4 diabetic patients and 100 mg14C-butylbiguanide orally to 5 further diabetics. The concentrations of the drug in plasma, intestinal fluid, intestinal epithelium and liver tissue were determined and the renal excretion of the biguanide measured. Irregularities in the plasma concentration curve were observed which appeared as systematic deviations from the ideal curve of a biexponential function. Because these deviations occurred only in the middle phase of the plasma concentration curve, it was nevertheless possible to calculate the pharmacokinetic parameters of butylbiguanide by use of a two-compartment open model. The principal pharmacokinetic parameters were determined according to this model after intravenous dosing and the following mean values were obtained:t 1/2 (β)=4.6 h (β=0.15 h−1),C P 0 =0.85µg/ml,V D =218 l,V T =157 l,V P =62 l,k 12=0.69 h−1,k 21=0.44 h−1,k el =0.54 h−1. Within 48 h after administration, an average of 72.4% of the intravenous and 74.4% of the oral dose had been excreted in the urine. Total clearance (Cl tot) averaged 536 ml/min and renal clearance (Cl ren) 393 ml/min. High concentrations of butylbiguanide were observed in the intestinal fluid (100–700 mg/ml) 20–40 min after oral administration. It was found that the drug accumulates in intestinal fluid, intestinal epithelium and liver tissue, and that it is secreted into the intestinal lumen. The concentrations of butylbiguanide in intestinal and liver tissue were 10–46 times higher than in plasma. The secretion of biguanide into the intestinal lumen may occur via the bile or the intestinal mucosa, but there is no evidence of significant biliary excretion of butylbiguanide.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 295-305 
    ISSN: 1432-1041
    Keywords: Mestranol ; ethynyloestradiol ; contraceptive compounds ; demethylation ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The oestrogenic activity of mestranol depends on its demethylation to ethynyloestradiol. The reaction has been studied in man. The compound disappeared exponentially from plasma during the first 4 h after i.v. injection of [4-14C-] mestranol. The “metabolic clearance” for this phase amounted to 31.8 1/day per kg body weight. Methoxy-3H-labelled mestranol was prepared for the further studies, because if it is demethylated, the tritium would be transferred to HTO, which would equilibrate immediately with body water. The appearance in body water of tritium from [methoxy-3H-] mestranol could be described by two exponential functions, which corresponded to bi-phasic disappearance of the original compound from plasma. The rate constant of the first stage was: γ1=0.835 h−1, and of the second: γ2=0.034 h−1. HTO radioactivity was eliminated from the body by exchange of water. From the data obtained, a three-compartment model was constructed of the transfer of tritium from [methoxy-3H-] mestranolinto body water, which permitted computer simulation of the partial processes. The compartmental analysis suggested that mestranol differed from ethynyloestradiol mainly in the delayed and protracted manner in which hormonally active oestrogen entered the circulation. The proportion of [methoxy-3H-] mestranol demethylated to ethynyloestradiol (demethylation ratio) varied little, 53.7±5.0% (x±SD; n=6), and was consistent with clinical observations that mestranol is half as potent an oestrogen as ethynyloestradiol. Thus, the dose of mestranol required to produce a given effect has to be twice as large as that of ethynyloestradiol.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 375-380 
    ISSN: 1432-1041
    Keywords: Tranexamic acid ; pharmacokinetics ; man ; antifibrinolytic agents ; renal clearance ; two-compartment model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The pharmacokinetics of tranexamic acid has been investigated in two healthy volunteers. The behaviour of the drug can be described in terms of a two compartment open model; the disposition (biological) half-life was 2.7 h and 1.9 h, respectively. In five normal volunteers the mean total recovery in urine 48 h after dosing was 94.8%. The renal clearance in the two subjects, adjusted to 1.73 m2 body surface area, was 135 and 132 ml/min/1.73 m2, respectively, indicating that tranexamic acid is eliminated by glomerular filtration and that neither tubular excretion nor absorption takes place.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 381-385 
    ISSN: 1432-1041
    Keywords: Phenazone ; pharmacokinetics ; plasma half-life ; gas chromatographic analysis ; intra-individual variability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Intra-individual variability in the plasma half-life of phenazone has been studied in 16 healthy, young volunteers. Phenazone was analysed by a simple gas chromatographic method, which is specific in relation to known metabolites; 4′-methylphenazone was employed as the internal standard. Phenazone was given on two occasions, two or three months apart, in oral doses of 10 mg/kg. The plasma half-life determined from five time points was 10.9±1.5 h and 11.2±1.3 h respectively, on the two occasions. The mean intra-individual variability (0.86 h) was close to the methodological error of 4%.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 25-29 
    ISSN: 1432-1041
    Keywords: Pindolol ; uraemia ; pharmacokinetics ; β-blockade
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The elimination of pindolol in 25 patients with various degrees of renal failure has been studied after an intravenous dose of 3 mg. A linear correlation was not found between the elimination rate of pindolol and the endogenous creatinine clearance, and the half-life of the unchanged drug was independent of the severity of the renal failure. This implies greater metabolism of pindolol in anuric patients and the extrarenal elimination rate constantk mwas increased. Three patients with severe renal failure were given 3 mg14C-pindolol. They showed almost constant plasma levels of radio-activity for 6 h and then slow excretion with a half-life of 48 h, because of accumulation of metabolites in the blood. Up to 90% of the metabolites are glucuronides and sulphates which have no beta-blocking or other clinical activity. Thus, to produce beta-adrenergic blockade the same dose of indolol is required in healthy patients as in those with uraemia.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 59-60 
    ISSN: 1432-1041
    Keywords: Pizotifen ; isonicotinylhydrazine ; orexigen ; tuberculosis ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Pizotifen (BC 105) has an orexigenic effect in patients with pulmonary tuberculosis. As these cases are often treated with isonicotinylhydrazine (INH), any effect of one of these drugs on the absorption of the other has been examined in a cross-over study in 8 healthy male volunteers. No difference was found between the absorption of INH given alone or together with pizotifen. It should be safe, therefore, to employ the combination of the orexigenic drug and INH in the treatment of tuberculosis as there will be no change in the concentration of therapeutic drug achieved.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 31-37 
    ISSN: 1432-1041
    Keywords: Diphenylhydantoin ; uraemia ; protein binding ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Diphenylhydantoin (2 mg/kg) was infused intravenously in four uraemic patients and four healthy volunteers and its plasma concentration measured during and after the infusion. The plasma concentrations were considerably lower in the uraemic subjects and the apparent volume of distribution was higher. These observations could be explained by the lower plasma protein binding of diphenylhydantoin in the uraemics. The overall elimination rate constant β was greater (shorter half-life) in the uraemic patients. This difference could not be explained by reduced plasma protein binding, but it might be due to induction of diphenylhydantoin metabolism in the uraemic state. it is concluded that monitoring of the plasma levels of drugs in uraemic patients should be combined with determination of the extent to which the compounds are bound to plasma proteins.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 51-58 
    ISSN: 1432-1041
    Keywords: Rifampicin ; plasma level ; pleural fluid concentration ; microbiological assay ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Single oral doses of rifampicin (RMP) were given to 31 patients with pleural effusions of various aetiologies. The concentrations of RMP and its active metabolites in pleural fluid and plasma were determined by an agar diffusion method using paper discs as diffusion centres. The plasma concentrations reached a peak within 3 h and then declined monoexponentially; in pleural fluid, RMP concentration rose slowly to reach a plateau that lasted for several hours. There were marked differences between subjects in the observed concentrations of RMP. During the first 12 h the plasma levels exceeded those in pleural fluid, but after 24 h the concentration of RMP in pleural fluid was higher than in plasma. If multiple oral doses of RMP 10 mg/kg b. w. are given every 24 h, as is common in the treatment of tuberculosis, therapeutic concentrations may be expected in pleural fluid for the major part of each day.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 17-24 
    ISSN: 1432-1041
    Keywords: Pindolol ; beta-blockade ; pharmacokinetics ; man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The kinetics of absorption, distribution and excretion of pindolol have been investigated in 17 volunteers after an oral dose or intravenous infusion of 5 mg. The calculated absorption was 92%. The time course of the plasma levels appeared to follow first order kinetics with an apparent half life of 3.6 (oral) and 3.1 (i.v.) hours. The cumulative urinary excretion att=∞ was 36.1% and 39.2% of the dose administered, respectively, indicating extensive metabolism of the drug. The distribution volume was 136 l. Peak plasma levels were found 80 min after oral administration and they showed up to 4-fold variation after identical doses. Renal clearance was 216 ml×min−1 and total clearance was 483 ml×min−1. In plasma 57% of pindolol was bound to protein.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 119-124 
    ISSN: 1432-1041
    Keywords: Anticonvulsants ; phenytoin ; diphenylhydantoin ; bioavailability ; generic inequivalence ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The plasma levels of phenytoin (diphenylhydantoin, DPH) in epileptic patients were significantly higher after treatment with either of two preparations containing the sodium salt of DPH, than after treatment with the same dose of the free acid. This was confirmed in both short and long term studies, and in the latter increased plasma levels of DPH were accompanied by better control of generalized seizures. The degree of acute side-effects in 6 out of 10 patients whose treatment was changed from DPH-acid to DPH-sodium was proportional to the plasma level of DPH; the latter varied from 22.8 to 34.9 µg/ml in affected patients. After a single oral dose in healthy volunteers, the sodium salt of DPH showed much better bioavailability than the free acid. The differences in bioavailability in patients and volunteers probably depended on differences in particle size in the preparations of the sodium salt of DPH and its free acid. The excipient, lactose or starch, did not seem to affect the bioavailability of the two formulations of sodium-DPH.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 217-225 
    ISSN: 1432-1041
    Keywords: Rifampicin ; p-aminosalicylic acid ; drug interaction ; isoniazid ; pharmacokinetics ; antituberculous therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Single oral doses of rifampicin (10 mg/kg body weight), p-aminosalicylic acid (0.2 g/kg), isoniazid (10 mg/kg), or rifampicin and either p-aminosalicylic acid or isoniazid, were given to 69 tuberculous patients with normal renal and hepatic function. Ten-fold interindividual differences were observed in the peak serum concentrations and half-lives of rifampicin; its half-life was reduced from 4.3 h after the first dose to 3.1 h after the third dose, possibly due to self-induction of its own metabolism. No effect on its serum concentration or half-life, nor on those of isoniazid, were found after simultaneous oral administration of the two drugs. After treatment with rifampicin and p-aminosalicylic acid, the peak serum level of the former was delayed from 2 to 4 h, it was reduced from 8.0 to 3.8 µg/ml, and the mean area under the serum concentration curve throughout the entire 8 h study period was also lowered by about half. Individual patients did not attain therapeutically effective peak serum concentrations of rifampicin if also treated withp-aminosalicylic acid. The interaction observed between the two drugs is probably due to impaired gastrointestinal absorption of rifampicin, either by alteration of its physico-chemical properties or by a decrease in the gastric emptying rate combined with more rapid intestinal transit. The combination of these two drugs is unsuitable for the routine chemotherapy of tuberculosis.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 7 (1974), S. 249-252 
    ISSN: 1432-1041
    Keywords: Practolol ; renal failure ; uraemia ; beta-blockade ; pharmacokinetics ; man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The effect of renal failure on the excretion of oral doses of practolol has been studied. The plasma half-life increased up to 6.6 times normal and the cumulative urinary excretion of the drug was reduced. There was a linear correlation between the overall elimination rate constant of practolol and inulin and creatinine clearances. A linear correlation was also found between the renal clearances of practolol and inulin. The dose of practolol required for maintenance therapy should be reduced in patients with impaired renal function.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 2 (1974), S. 123-148 
    ISSN: 1573-8744
    Keywords: pharmacokinetics ; computer program ; NONLIN ; data weighting ; isoniazid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Several important statistical aspects of pharmacokinetic analyses by digital computer are discussed. These include selection of appropriate equations, weighting of data, precision of parameter estimates, comparisons of parameters, analysis of weighted residuals, and criteria useful in the selection of particular models. Data obtained after administration of isoniazid and isonicotinuric acid to man are analyzed to illustrate the usefulness of the discussed methods.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 2 (1974), S. 495-509 
    ISSN: 1573-8744
    Keywords: hepatobiliary transport ; rat ; bromphenol blue ; pharmacokinetics ; roles of liver cytoplasmic Y- and Z-binding proteins and T binder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new pharmacokinetic model is proposed to explain the hepatobiliary transport of a nonmetabolized sulfonic acid dye, bromphenol blue, which is actively transported from the bloodstream into bile. This model has the advantage of taking into account the roles of the liver cytoplasmic Y- and Z- binding proteins and T binder.
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  • 16
    ISSN: 1573-8744
    Keywords: digoxin ; pharmacokinetics ; two-compartment model ; three-compartment model ; radioimmunoassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An experiment has been carried out in man designed to compare the fit of a two- and a three-compartment pharmacokinetic model to experimentally determined serum digoxin concentration-time data following rapid intravenous injection of 1.0 mg of the drug. Digoxin was administered to five healthy male volunteers, blood samples were withdrawn repetitively over a period of 72 hr, and samples were assayed using a 125 I radioimmunoassay. Appropriate equations describing two- and three-compartment open models were fitted to the experimental data using weighted nonlinear least squares regression analysis. It was demonstrated that the three-compartment fit resulted in a statistically significant reduction in residual error, a marked improvement in the randomness of scatter of the experimental data about the serum digoxin-time curve, and better agreement of the predicted serum concentration-time curve with experimental serum digoxin concentrations. Thus the three-compartment open model is the simplest pharmacokinetic model consistent with the data observed in this experiment.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Journal of pharmacokinetics and pharmacodynamics 2 (1974), S. 347-364 
    ISSN: 1573-8744
    Keywords: metoprolol ; β-receptor antagonist ; pharmacokinetics ; disposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of 3H-metoprolol, a new selective β 1-receptor antagonist, have been studied in healthy volunteers by following the plasma concentrations and the urinary excretion of the unchanged compound and its total radioactive metabolites after oral and intravenous administration. The compound was rapidly and completely absorbed after oral administration, and about 40% of the dose reached the systemic circulation. The estimated half-life of the absorption process was 10 min. Metoprolol was extensively distributed to extravascular tissues, with the half-life of the distribution phase close to 12 min. About 95% of the dose was excreted in the urine within 72 hr, mainly in metabolized form. The elimination halflife of the compound was close to 3 hr as was also the half-life of the total metabolites after oral administration. After intravenous administration, the elimination half-life of the metabolites was raised to 5 hr, indicating that the route of administra tion might influence the metabolic pathways of the parent compound.
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  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 68-77 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties, XXVI. The Delocalisation of Sulfur Electron Pairs in Sulfides and DisulfidesThe photoelectron (PE) spectra of sulfides R—S—R (R=H, CH3, C2H5, n- und i-C3H7, n- and tert-C4H9) and disulfides R—S—S—R (R=H, CH3, C2H5, n- and i-C3H7, tert-C4H9, —[CH2]4—) are comparatively discussed. For sulfides the first ionization energy, which decreases as expected with increasing degree of alkylation, can also be obtained from the charge transfer excitation energies of their σ-complexes with tetracyanoethylene (TCNE). Disulfides show a splitting of the first PE-band in a clear dependence on the dihedral angle of the sulfur electron pairs. All observations can be rationalised within MO models as interactions of the sulfur electron pairs with the σ-skeleton and/or with each other.
    Notes: Die Photoelektronen(PE)-Spektren von Sulfiden R—S—R (R=H, CH3, C2H5, n- und i-C3H7, n- und tert-C4H9) und Disulfiden R—S—S—R (R=H, CH3, C2H5, n- und i-C3H7, tert-C4H9, —[CH2]4—) werden vergleichend diskutiert. Bei den Sulfiden R—S—R kann die mit steigendem Alkylierungsgrad erwartungsgemäß abnehmende erste Ionisierungsenergie auch aus den Charge-transfer-Anregungsenergien ihrer σ-Komplexe mit Tetracyanäthylen (TCNE) abgelesen werden. Bei Disulfiden R—S—S—S—R wird eine Aufspaltung der ersten PE-Bande in deutlicher Abhängigkeit vom Diederwinkel zwischen den Schwefel-Elektronen-paaren beobachtet. Die Befunde lassen sich mit MO-Modellen als Wechselwirkungen der Schwefel-Elektronenpaare mit dem σ-Gerüst und/oder untereinander verstehen.
    Additional Material: 6 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 93-101 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nickelalkyl Ylid ComplexesFrom reactions of [(CH3)3P]3 Ni(CH3)2 and [(CH3)3P]2Ni(CH3)Cl with the ylid (CH3)3PCH2, molecular (1) an ionic complexes (2) are obtained, containing three covalent Ni—C-σ-bonds of square planar nickel atoms. These bonds are strongly stabilized by the proximity of the ylid onium center. Excess ylid converts 2 into a binuclear complex 3, where the metal atoms are bridged by dimethylphosphonium-bismethylid units, with formation of [(CH3)4P]Cl as a byproduct. An isoelectronic dimethylphosphinate complex, 4, containing a similar eight-membered ring structure, has also been prepared.
    Notes: Durch die Reaktion von Dimethyltris(trimethylphosphin)nickel und Methylbis(trimethyl-phosphin)nickel-chlorid mit Trimethylmethylenphosphoran werden molekulare (1) bzw. ionische (2) Ylid-Komplexe erhalten, in denen das quadratisch-planar konfigurierte Nickel-atom jeweils drei kovalente Ni—C-σ-Bindungen ausbildet. Diese Bindungen werden durch das Onium-Zentrum der Ylide erheblich stabilisiert. 2 liefert mit überschüssigem Ylid unter Abspaltung von [(CH3)4P]Cl einen zweikernigen Komplex 3, dessen Metallatome durch Dimethylphosphonium-bis-methylid-Brücken verbunden sind. Hierzu existiert ein isoelektronischer Dimethylphosphinat-Komplex 4, der ebenfalls Achtringstruktur besitzt.
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  • 20
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 123-127 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of carbonyl-stabilized Sulfonium-ylides of 1,3-Dithiolane with Acylating Reagents and Activated AcetylenesIn aqueous sodium hydroxide monophenacyl-1,3-dithiolanium bromides 3 form carbonylstabilized 1,3-dithiolanium-1-phenacylides 4. These yield with acylation reagents and activated acetylenes new resonance-stabilized sulfonium-ylides 6, 8, 10.
    Notes: Monophenacyl-1,3-dithiolanium-bromide 3 bilden in wäßriger Natronaluge carbonyl-stabilisierte 1,3-Dithiolanium-1-phenacylide 4. Diese reagieren mit Acylierungsmitteln und aktivierten Acetylenen zu neuen mesomeriestabilisierten Sulfonium-yliden 6, 8, 10.
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  • 21
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 145-151 
    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, IX. On Pyruvoyl Amino AcidsAmino acid derivatives were tranformed to Pyruvoyl amino acid derivatives by use of pyruvoyl chlorid, p-nitrophenyl pyruvate, hydroxymaleic anhydride and the DCC-procedure. The application range of the different acylations is discussed. A convenient method for the preparation of pyruvoyl chloride is given.
    Notes: Aminosäurederivate werden mit Brenztraubensäurechlorid, Brenztraubensäure-p-nitrophenylester, Hydroxymaleinsäureanhydrid und mit Hilfe des DCC-Verfahrens zu Pyruvoylaminosäurederivaten umgesetzt. Die Anwendungsbreite der verschiedenen Acylierungen wird verglichen. Ein Weg zur praktischen Herstellung von Brenztraubensäurechlorid wird ausgearbeitet.
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  • 22
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 253-262 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of Hexakis(phenylthio)ethaneThe structure of hexakis(phenylthio)ethane has been determined by single crystal X-ray diffraction. The phase determination was carried out by means of the Symbolic Addition Method. The structure has been refined with 1780 observed reflections to an R-value of 10.9%. The pseudo bodycentered unit cell contains two molecules, which are situated at the center at 0, 0, 0 and 1/2, 1/2, 1/2, respectively. The bodycentering is almost perfect for the six sulfur atoms, but does not involve the central ethane bonding, which implies that the sulfur atoms, that are connected by the centering, are bonded to different carbon atoms. The six sulfur atoms are staggered around the ethane C—C bond. The S—C—S angles of 113° are larger than the ideal tetrahedrane angles by the same amount by which the S—C—C angles of 105° are smaller. The ethane C—C distances are 1.59 and 1.56 Å respectively.
    Notes: Die Struktur des Hexakis(phenylthio)äthans wurde mit Röntgenmethoden bestimmt. Die Phasenbestimmung wurde mit der symbolischen Additionsmethode durchgeführt. Die Struktur wurde unter Benutzung von 1780 beobachteten Reflexen bis auf einen R-Wert von 10.9% verfeinert. Die pseudoinnenzentrierte Elementarzelle enthält zwei Moleküle, die um die Symmetriezentren in 0, 0, 0 bzw. 1/2, 1/2, 1/2 gelagert sind. Die Innenzentrierung ist nahezu genau für die sechs Schwefelatome, aber gilt nicht für die zentrale Äthanbindung, was zur Folge hat, daß die durch Zentrierung verbundenen Schwefelatome an verschiedene Kohlenstoffatome gebunden sind. Die sechs Schwefelatome sind gestaffelt um die Äthan-C—C-Bindung angeordnet. Die S—C—S-Winkel sind mit 113° etwas größer, die S—C—C-Winkel mit 105° um denselben Betrag kleiner als der Tetraederwinkel. Die Äthan-C—C-Abstände betragen 1.59 bzw. 1.56 Å.
    Additional Material: 5 Ill.
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  • 23
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 305-316 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Benzothiazole N-Oxides, II. New Synthesis of Substituted 2-BenzothiazolonesIn the presence of phosphoryl chloride, 2-carbamoylbenzothiazole N-oxides undergo a new intramolecular redox reaction to give 2-benzothiazolones. In two cases investigated, also 2-ethoxycarbonylbenzothiazole N-oxides undergo this rearrangement. The spectroscopic data are discussed.
    Notes: 2-Carbamoylbenzothiazol-N-oxide gehen in Gegenwart von Phosphoroxychlorid eine neuartige intramolekulare Redoxreaktion unter Bildung von 2-Benzothiazolonen ein. In zwei untersuchten Fällen unterliegen unterliegen auch 2-Äthoxycarbonylbenzothiazol-N-oxide dieser Umlagerung. Spektroskopische Daten werden diskutiert.
    Additional Material: 7 Tab.
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  • 24
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Aromatic Sulfenyl Chlorides, IX. Preparation, Oxidation, and Spectroscopic Investigation of 1-Substituted 5-Tetrazolyl Aryl Disulfides1-Substituted 5-tetrazolyl mesityl disulfides were synthesized which on oxidation with hydrogen peroxide gave disulfide S2, S2-dioxides (thiolsulfonates). The structure of these as well as that of the 1-substituted 5-tetrazolyl p-tolyl disulfide S2, S2-dioxides synthesized earlier was elucidated by means of their i. r. and n. m. r. spectra. The supposed structures have been established by synthesis.
    Notes: Es wurden 1-substituierte (5-Tetrazolyl)mesityldisulfide hergestellt, welche zu Disulfid-S2, S2-dioxiden (Thiosulfonate) oxidiert wurden. Deren Struktur und die der früher hergestellten 1-substituierten (5-Tetrazolyl)p-tolyldisulfid-S2, S2-dioxide wurde anhand ihrer IR- und NMR-Spektren wahrscheinlich gemacht. Die angenommenen Strukturen wurden durch Synthese bewiesen.
    Additional Material: 2 Tab.
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  • 25
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 367-379 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Lithio-1,3,5-trithianes Generation in Solution, Reactions with Electrophiles, and Use in Nucleophilic Acylation1,3,5-Trithiane and 2-mono- as well as 2,4,6-trisubstituted trithianes are shown to be metallated by n-butyllithium in THF. Reaction of the lithio derivatives thus obtained with electrophiles leads to more highly substituted trithianes which in some cases can be isolated in a pure form. The n.m.r. spectra of the products at room temperature are described. Mercury(II)-assisted solvolysis of alkyltrithianes „liberates“ the most highly substituted carbon with formation of carbonyl compounds or their O-acetals. This completes a sequence of reactions which suggests use of lithiotrithianes as reagents for nucleophilic acylation. Advantages and disadvantages of this procedure compared to the dithiane method are discussed.
    Notes: 1,3,5-Trithian selbst sowie 2-mono- und 2,4,6- trisubstituierte Trithiane lassen sich mit n-Butyllithium in Tetrahydrofuran metallieren. Umsetzung der Lithiumderivate mit Elektrophilen führt zu höher substituierten Trithianen, die teilweise in reiner Form isoliert werden können. Die NMR-Spektren der erhaltenen Produkte bei Raumtemperatur werden beschrieben. Quecksilber(II)-assistierte Solvolyse von alkylierten Trithianen führt zu Carbonyl-verbindungen oder deren O-Acetalen unter „Herauslösung“ des höchstsubstituierten C-Atoms, was die Verwendung von Lithiotrithianen als nucleophile Acylierungsmittel ermöglicht. Vor- und Nachteile gegenüber der Dithian-Methode werden diskutiert.
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  • 26
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Dependence of the Bond-length in some N,O-Dibenzoylhydroxylamines on the Torsion of the Carboxylic and Hydroxamic Groups against the Benzene Nuclei. The Crystal Structures of N,O-Dibenzoyl-(C14H11NO3), N,O-Bis(2-chlorobenzoyl)-(C14H9Cl2NO3), N-BenzoylO-p-toluoyl- (C15H13NO3), and N-Benzoyl-O-o-toluoylhydroxylamines (C15H13NO3)The crystal structures of four N,O- dibenzoylhydroxylamines - 1: N,O-dibenzoylhydroxylamine (C14H11NO3), 2: N,O- bis(2-chlorobenzoyl)hydroxylamine (C14H9Cl2NO3), 3: N-Benzoyl-O-p toluoylhydroxylamine (C15H13NO3), 4: N-benzoyl-O-o- toluoylhydroxylamine (C15H13NO3) - have been determined by X-ray techniques, using direct methods for phase determination. The torsion angles ϕ of the C—C- bonds between the phenyl groups and the hydroxamic acid groups or the carboxylic groups, respectively, have been calculated. The values of the intramolecular distances of these bonds, plotted versus cos2 ϕ, can be approximated by a straight line. Extrapolating to ϕ = 90°, the pure sp2-sp2-C—C-single-bond is found to be 1.513 Å.
    Notes: Die Kristallstrukturen von vier N,O- Dibenzoylhydroxylaminen - 1: N,O-Dibenzoylhydroxylamin (C14H11NO3), 2: N,O -Bis(2-chlorbenzoyl)hyroxylamin (C14H9Cl2NO3), 3: N-Benzoyl-O-p-toluoylhydroxylamin (C15H13NO3), 4: N- Benzoyl-O-o-toluoylhydroxylamin (C15H13NO3) - wurden röntgenographisch unter Anwendung direkter Methoden zur Lösung des Phasenproblems bestimmt. Die C—C- Bindungslängen zwischen den Phenylgruppen einerseits und den Hydroxamsäure- bzw. Carboxylatgruppen andererseits lassen sich als Funktion der Verdrillungswinkel ϕ dieser Bindung durch eine Gerade darstellen, wenn man die Bindungslängen gegen cos2 ϕ aufträgt. Der reine sp2-sp2-C—C- Einfachbindungsabstand (ϕ = 90°) ist danach 1.513 Å.
    Additional Material: 10 Ill.
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  • 27
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 680-685 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of Tetracyclo[3.3.0.02.8.04.6]octan-3-ones by Intramolecular Thermal [2π + 2σ]-CycloadditionThe synthesis of the tetracyclooctanone 19 by thermolysis of the tricyclic acetal 15 and subsequent removal of the acetal group is described. Thus, a third synthetic access to this system is now available. The reaction involves the cycloaddition of a thermally ring-opened cyclopropane to a double bond.
    Notes: Die Synthese des Tetracyclooctanons 19 durch Thermolyse des tricyclischen Acetals 15 und anschließende Entacetalisierung wird beschrieben. Damit bietet sich ein dritter synthetischer Zugang zu diesem System an. Die Reaktion beinhaltet die Cycloaddition eines thermisch ringgeöffneten Cyclopropans an eine Doppelbindung.
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  • 28
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 717-720 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 29
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 731-734 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 30
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 785-795 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pteridines, LX. Synthesis and Autoxidation of 7, 8-DihydroxanthopterinsThe synthesis of 7,8-dihydroxanthopterin (18) and of various N- and C-methyl derivatives (19-27, 30) is described. Their pKa values and u.v. spectra have been determined and the behaviour during autoxidation has been investigated. The monoanions are subject to autoxidation which is catalysed strongly by ammonia and primary amines. A mechanism for the autoxidation is discussed in which the existence of various intermediates is based on the oxidative behaviour of differently blocked N- und C-methyl derivatives.
    Notes: Die Synthese des 7,8-Dihydroxanthopterins (18) und verschiedener N- und C-Methyl-Derivate (19-27, 30) wird beschrieben. Ihre pKa-Werte und UV-Spektren werden bestimmt und ihr Autoxidationsverhalten untersucht. Die Monoanionen unterliegen der Autoxidation, welche durch Ammoniak und primäre Amine stark katalysiert wird. Ein Mechanismus wird diskutiert und verschiedene Zwischenprodukte anhand von blockierten N- und C-Methyl-Derivaten wahrscheinlich gemacht.
    Additional Material: 4 Ill.
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  • 31
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 832-837 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of 6,6-Bis(dimethylamino)fulvene6,6-Bis(dimethylamino)fulvene crystallizes in the space group Pn21a, the lattice constants being ao = 13.344 Å, bo = 7.844 Å and co = 9.438 Å. The structure has been solved by superposition and by direct methods in the space group Pnma. The structure was refined by block-diagonal-least-squares to R = 0.037.
    Notes: Das 6,6-Bis(dimethylamino)fulven kristallisiert in der Raumgruppe Pn21a mit den Gitter-konstanten ao = 13.344 Å, bo = 7.844 Å und co = 9.438 Å. Die Struktur wurde durch Superposition und anschließende Resymmetrisierung der Patterson-Funktion und mit direkten Methoden in der zentrosymmetrischen Obergruppe Pnma gelöst.
    Additional Material: 2 Ill.
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  • 32
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 847-853 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Bromine/Lithium Exchange in Vinyl and Aryl Bromides with tert-Butyl Lithium. On the Ring Enlargement via Dibromocarbene AdductsTwofold molar excess of tert-butyl lithium replaces vinylic and arylic bromine by lithium. The tert-butyl bromide formed is dehydrohalogenated rapidly to isobutene by tert-butyl lithium even at very low temperatures. Transformation of 1-bromo-1-cyclooctene and - cyclononene via the lithium derivatives to vinyl thioethers 1d, e, and i in high yields opens up a simple alternative route from olefin dibromocarbene adducts to ring enlarged ketones. The bromobenzenes 2a and 3a reveal that the Br/Li-exchange described here is not accompanied by arine formation; it is feasible even in the presence of sensitive benzylic CH2-groups as present in 3.
    Notes: Vinylisch und an Aromaten gebundenes Brom läßt sich quantitativ mit zweifachem molarem Überschuß an tert-Butyllithium gegen Lithium austauschen. Das entstehende tert-Butylbromid wird selbst bei tiefen Temperaturen von tert-Butyllithium rasch zu Isobuten dehydrohalogeniert. Die Überführung von 1-Brom-1-cycloocten und -1-cycloneone in Vinylthioäther 1d, e und i über die Lithiumderivate ist in hoher Ausbeute möglich und eröffnet einen einfachen Weg von Dibromcarbenaddukten an Olefine zu ringerweiterten Ketonen. Am Beispiel der Brombenzole 2a und 3a wird gezeigt, daß der hier beschriebene Br/Li-Austausch nicht von Arin-Bildung begleitet und auch in Gegenwart der empfindlichen benzylischen CH2-Gruppe von 3 durchführbar ist.
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  • 33
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 892-897 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-VinylimidazolecarboxylatesN-Vinylation of imidazolecarboxylates with vinyl acetate leads to the formation of the N-vinylimidazoles 3a, 3b, 6, 8a, 8b und 9a. The structures are determined by mass and n.m.r. spectra. 3a, 6, 8a are polymerizable.
    Notes: Durch N-Vinylierung von Imidazolcarbonsäureestern mit Vinylacetat werden die N-Vinylimidazole 3a, 3b, 6, 8a, 8b und 9a, erhalten. Die Strukturen werden mit Hilfe von NMR-und Massen-Spektren gesichert. 3a, 6, 8a und 8bsing polymerisationsfähig.
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  • 34
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 929-936 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclizations, XIII. New Polycyclic Pyrimidines with Bridge-Head NitrogenThe base-catalized condensation of 2,3,3-trimethyl-3H-benz[f]indole (9) with dielectrophilic iso(thio)cyanates to polycyclic pyrimidines with bridge-head nitrogen (11, 15, 16) in most cases involves preliminary formation of 1: 2 adducts followed by elimination of diacylamides. Contrary to this the less nucleophilic 2,3,3-trimethyl-3H-pyrrolo [2,3-b]pyridine (20) affords the analogue pyrimidines by intermediacy of 1:1 adducts and elimination of water or ethanol solely.
    Notes: Die basenkatalysierte Kondensation von 2,3,3-Trimethyl-3H-benz[f] indol (9) mit dielektrophilen Iso(thio)cyanaten zu polycyclischen Pyrimidinen mit Brückenkopf-Stickstoff (11, 15, 16) verläft meist über die Bildung von 1:2-Addukten als Zwischenstufe und Eliminierung von Diacylamiden. Dagegen liefert das weniger nucleophile 2,3,3-Trimethyl-3 H-pyrrolo[2.3-b]-pyridin (20) analoge Systeme (22, 23) ausschließlich über 1: 1-Addukte und Eliminierung von Wasser bzw. Äthanol.
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  • 35
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 686-697 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkaloids from Rhamnaceae, XVIII. Amphibine-F, -G and -H, further Peptide Alkaloids from Ziziphus amphibia A. Cheval.From the complex mixture of crude alkaloids from Ziziphus amphibia A. Cheval., in addition to the already described Amphibines-A, -B, -C, -D and -E, three further peptide alkaloids Amphibine-F, -G and -H have been isolated and their structures elucidated (1-3). Amphibine-F and -G (1, 2) belong to the class of cyclic peptide alkaloides having a fourteen-membered ring system made up from trans-3-hydroxyproline, p-hydroxystyrylamine and an α-aminoacid. Amphibine-H (3) has a thirteen-membered ring system formed from 5-hydroxy-2-methoxystyrylamine and the aminoacids trans-3-hydroxyproline and phenylalanine.
    Notes: Aus dem komplexen Rohbasengemisch von Ziziphus amphibia A. Cheval. wurden neben den bereits beschriebenen Amphibinen-A, -B, -C, -D und -E drei weitere Peptidalkaloide Amphibin-F, -G und -H isoliert und in der Struktur geklärt (1-3). Die Amphibine-F und -G (1, 2) zählen zu den Cyclopeptidalkaloiden mit 14 gliedrigem Ringsystem aus trans-3-Hydroxyprolin, p-Hydroxystyrylamin und einer α-Aminosäure. Das Amphibin-H (3) weist ein 13 gliedriges Ringsystem auf, das aus den Aminosäuren trans-3-Hydroxyprolin und Phenylatanin sowie aus 5-Hydroxy-2-methoxystyrylamin gebildet wird5).
    Additional Material: 3 Ill.
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  • 36
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 698-705 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Preparation of New ChloroformamidinesAction of phosphine/carbon tetrachloride or dichlorotriphenylphosphorane on N,N,N′-trisubstituted ureas leads to the formation of even such chloroformamidines which are not or only difficultly obtainable by the conventional methods. The spectroscopic and analytic data of the new compounds are given.
    Notes: Durch Einwirkung von Phosphin/Tetrachlorkohlenstoff oder von Dichlortriphenylphos-phoran auf N,N,N′-trisubstituierte Harnstoffe können auch solche Chlorformamidine dargestellt werden, die nach den bisherigen Methoden nicht oder nur schwer zugänglich sind. Die spektroskopischen und analytischen Daten der neuen Verbindungen sind angegeben.
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  • 37
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 721-724 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 38
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 725-726 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 39
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 739-744 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterosubstituted Fulvenes, VIII. Indeno[2,1-c]-1,2-dithioles, a Group of New PseudoazulenesAcylation of 2-pyrrolidinoindene (4) with carboxylic acid chlorides and subsequent hydrolysis leads to the 1-acyl-2-indanones 6, which have been condensed with diacetyl disulfide in aequous perchloric acid/acetic acid to afford the 8H-indeno[2,1-c]-1,2-dithiolium-perchlorates 7. These are deprotonated with N-ethyldiisopropylamine to yield the indeno[2,1-c]-1,2-dithioles 10, a group of new pseudoazulenes.
    Notes: Acylierung von 2-Pyrrolidinoinden (4) mit Carbonsäurechloriden und nachfolgende Verseifung liefert die 1-Acyl-2-indanone 6, die mit Diacetyldisulfid in wäßriger Perchlorsäure, Eisessig zu den 8H-Indeno[2,1-c]-1,2-dithiolium-perchloraten 7 kondensieren. Letztere lassen sich durch N-Äthyldiisopropylamin zu den Indeno[2,1-c]-1,2-dithiolen 10, einer Gruppe neuer Pseudoazulene, deprotonieren.
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  • 40
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 759-770 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry and Reactivity of Tetrahalogenated 2,3-Diazabicyclo[3.2.0]hept-2-enes and Bicyclo [2.1.0] pentanesThe addition of diazoalkanes to tetrahalogenated cyclobutenes 1-3 leads to 6,6,7,7-tetrahalo-2,3-diazabicyclo[3.2.0]hept-2-enes 4-8, the structure and stereochemistry of which are determined by means of n. m. r. spectroscopy. Thermal decomposition of 4, 5, and 8 in boiling toluene affords the tetrahalobicyclo[2.1.0]pentanes 9, 10, and 12 in good yields. Under the same conditions 7 decomposes in a stereospecific manner to form 11 and small amounts of 13. Sodium methoxide converts 9-11 into the cyclobutenes 14 and 15. Under the influence of sulfuric acid 10 forms the cyclobutenedione 16 or a mixture of cyclopentenones 18, 19 depending on the reaction conditions.
    Notes: Addition von Diazoalkanen an die tetrahalogenierten Cyclobutene 1-3, führt zu 6,6,7,7-Tetrahalogeno-2,3-diazabicyclo[3.2.0]hept-2-enen 4-8, deren Konstitution und Stereochemie auf NMR-spektroskopischem Weg ermittelt wurde. Durch thermische Zersetzung der Bicyclen 4,5 und 8 in siedendem Toluol erhält man in guten Ausbeuten Tetrahalogenobicyclo-[2.1.0]pentane 9,10 und 12. Unter gleichen Bedingungen entstehen aus 7 in stereospezifischer Reaktion 11 sowie geringe Mengen des Cyclobutens 13. Mittels Natriummethylat werden die Bicyclen 9-11 zu den Cyclobutenen 14, 15 abgebaut; unter dem Einfluß von konz. Schwefelsäure entsteht aus 10 je nach Reaktionsbedingungen das Cyclobutendion 16 bzw. ein Gemisch der Cyclopentenone 18 und 19.
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  • 41
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1221-1227 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conversion of Aldehydes into Nitriles without Isolation of IntermediatesAldehydes are converted into nitriles without isolation of the intermediates by treating their oximes with carbodiimides in the presence of copper(II)ions and triethylamine. The entire process requires 3 hours at room temperature; it is unsuccessful if the oxime does not form or is consumed by competition reactions.
    Notes: Aldehyde können ohne Isolierung von Zwischenprodukten in Nitrile übergeführt werden, indem ihre Oxime in Gegenwart von Kupfer(II)-Ionen und Triäthylamin mit Hilfe von Carbodiimiden dehydratisiert werden. Der gesamte Prozeß erfordert bei Raumtemperatur durchweg 3 Stunden. Das Verfahren versagt, wenn die Oximbildung gestört ist oder das Oxim Konkurrenzreaktionen eingeht.
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  • 42
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactivity of Silicon Transition Metal Complexes, V. The Modified Alkali Salt Elimination Method  -  a General Procedure for the Synthesis of Silicon Transition Metal CompoundsThe heterogeneous reaction of the sodium carbonylmetallates Na[Fe(CO)2π-C5H5], Na[M(CO)3π-C5H5] (M=Mo, W), and Na[Mn(CO)5] with various halo- and organohalosilanes leads to the formation of the corresponding silyl complexes. The new compounds are characterized by spectroscopy and the chemical properties are described. The results of a decomposition study of the trimethylsilyl-VIB transition metal complexes are discussed in connection with former synthetic experiments. Exchange reactions of these species with heterosiloxanes can be used for a qualitative estimation of relative metal-metalloid bond reactivity.
    Notes: Die Umsetzung der komplexen Metallate Na[Fe(CO)2π-C5H5], Na[M(CO)3π-C5H5] (M=Mo, W) und Na[Mn(CO)5] mit verschiedenen Halogen- und Organohalogensilanen führt in heterogener Reaktion zu den Silylkomplexen dieser Metalle. Die neuen Verbindungen werden spektroskopisch charakterisiert und ihre chemischen Eigenschaften beschrieben. Die Ergebnisse einer Zerfallsstudie der Trimethylsilyl-VIB-Übergangsmetallkomplexe werden im Zusammenhang mit früheren Syntheseversuchen diskutiert. Der Verlauf von Austauschreaktionen der gleichen Verbindungen mit Heterosiloxanen (Ge, Sn) ermöglicht eine qualitative Abschätzung der Reaktivität der Metall- Metalloideinheit.
    Additional Material: 7 Tab.
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  • 43
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1057-1065 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on 4-Pyrones, 51. Aminoalkylation of ChromonesThe aminoalkylation of 2-methylchromones (1b, e and 2b, c) leads to the formation of benzopyrano[3.2-c]pyridinium chlorides (9a-d and 11a-e).
    Notes: Die Aminoalkylierung von 2-Methylchromonen (1b, e sowie 2b, c) führt zu Benzopyrano-[3.2-c]pyridinium-chloriden (9a-d sowie 11a-e).
    Additional Material: 2 Tab.
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  • 44
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1069-1069 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 45
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mass Spectrometric Investigation of Amides, VII. Intramolecular Interactions of Bifunctional Groups in the electron Impact Induced Fragmentation of Piperidides and PiperideidesThe activation energy ∊ for the electron impact induced splitting of the N-carbonyl bond in bifunctional amides is estimated. A clear correlation is shown of ∊ with the ring size of the transition state and the nucleofuge or nucleophilic properties of the nitrogen groups. Furtheron by means of [D]-labelled model compounds selective hydrogen migrations have been established.
    Notes: Die Aktivierungsenergie ∊ für die elektronenstoßinduzierte Spaltung der N-Carbonylbindung bifunktioneller Amide wird bestimmt. Es ergibt sich ein klarer Zusammenhang von ∊ mit der Ringgröße des Übergangszustandes und den nucleofugen bzw. nucleophilen Eigenschaften der Stickstoffgruppen. Ferner werden mit Hilfe [D]-markierter Modellverbindungen selektive Wasserstoffübertragungen nachgewiesen.
    Additional Material: 3 Tab.
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  • 46
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1126-1135 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Nature of Benzonorbornen-2-yl Cations, II. Solvolysis of Isopropylidene-substituted benzonorbornen-2yl EstersThe 2-epimeric at C-7 and C-3 substituted benzonorbornenols 4a, 6a, 7a and 8a are synthesized. The rate of solvolysis of the tosylates 4b and 6b is measured in acetic acid, that of the 3,5-dinitrobenzoates 7b and 8b in 90% dioxane. The solvolysis products are determined in 80% acetone puffered with 2,6-lutidine. The epimeric 7-isopropylidene derivatives 4b and 6b solvolyse by a different mechanism; the exo derivative 4b reacts exclusively with assistance of the benzene ring, the endo compound by participation of the homoallylic double bond. The epimeric 3-isopropylidene derivatives 7b and 8b solvolyse to a common intermediate allylic ion 10. The kexo/kendo ratio is reduced to 9 due to the presence of this neighbouring group, which is a measure of the steric factor in the secondary benzonorbornen-2-yl system.
    Notes: Die epimeren Benzonorborneole 4a und 6a sowie 7a und 8a werden synthetisiert. Die Solvolysegeschwindigkeit der Tosylate 4b und 6b wird in Eisessig, die der 3,5-Dinitrobenzoate 7b und 8b in 90 proz. Dioxan gemessen. Die Reaktionsprodukte werden in 80 proz., mit 2,6-Lutidin gepuffertem Aceton bestimmt. Die epimeren 7-Isopropyliden-Verbindungen 4b und 6b solvolysieren nach einem unterschiedlichen Mechanismus; die exo-Verbindung 4b reagiert ausschließlich mit Beteiligung des Aromaten, die endo-Verbindung 6b mit der der Isopropyliden-Doppelbindung. Die epimeren 3-Isopropyliden-Verbindungen 7b und 8b solvolysieren zu einem gemeinsamen Allyl-Ion 10 als produktbestimmende Zwischenstufe. Das Verhältnis kexo/kendo wird durch diese Nachbargruppe auf 9 herabgesetzt, welches ein Maß für den sterischen Anteil des sekundären Benzonorbornen-2-yl-Systems ist.
    Additional Material: 1 Ill.
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  • 47
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbene Complexes, LXXII. Cleavage of the Double Bond of 1-vinyl-2-pyrrolidone and β-Substituted 1-Vinylpyrrolidones by Reaction with Pentacarbonyl(methoxyphenylcarbene)chromium(0)Pentacarbonyl(methoxyphenylcarbene)chromium(0) reacts with 1-vinyl-2-pyrrolidone to form α-methoxystyrene by transfer of a methylene group to the carbene moiety. The origin of the transfered methylene group is proved by using methylsubstituted 1-vinylpyrrolidones. The reaction products are identified by their i.r., 1H n.m.r., and mass spectra. As reaction mechanism a cyclic transition state is proposed, which explains the breaking and following formation of a double bond analogously to the heterolytic fragmentation according to Grob.
    Notes: Bei der Umsetzung von Pentacarbonyl(methoxyphenylcarben)chrom(0) mit 1-Vinyl-2-pyrrolidon entsteht durch Übertragung einer Methylengruppe auf den Carben-Rest α-Meth-oxystyrol. Durch Einsetzen methylsubstituierter 1-Vinylpyrrolidone wird die Herkunft der übertragenen Methylengruppe bewiesen. Die Produkte werden anhand ihrer IR-, 1H-NMR- und Massenspektren identifiziert. Als Reaktionsmechanismus wird ein cyclischer Übergangszustand vorgeschlagen, der - in Analogie zur heterolytischen Fragmentierung nach Grob - die Spaltung und Neuknüpfung einer Doppelbindung erklärt.
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  • 48
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1207-1212 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemical Reactions, XXIII. The Photocyclisation of 9-Benzylidenexanthenes and 9-BenzylidenethioxanthenesDehydrocyclisations of the 9-benzylidenexanthenes in u.v. or sunlight (6a-6d→7a-7d) were realized. 6 may be considered as derived from stilbene, and 7 as derived from phenanthrene. Therefore the photoprocess 6→7 is analogue to the photoprocess cis-stilbene → phenanthrene.
    Notes: Dehydrocyclisierungen der Benzylidenxanthene im UV-oder Sonnenlicht (6a-6b→7a-7d) wurden durchgeführt. Da 6 als substituierte cis-Stilbene und 7 als substituierte Phenanthrene aufgefaßt werden können, liegen Analogiereaktionen zu dem Photoprozeß cis-Stilben → Phenanthren vor.
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  • 49
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1228-1234 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Dynamic Behaviour of Mono-cyclopentadienylarsinesMono-cyclopentadienylarsines (3a-e) are synthesized by the reaction of cyclopentadienyl-trimethylsilane (1) or cyclopentadienyllithium (5) with the halogenoarsines 2a-e. They are very sensitive against air and moisture and thermally unstable. The cp-ligands are σ-bonded; the molecules have a fluxional structure. The rapidity of the degenerate metallotropic rearrangements is influenced by the other ligands on the arsenic atom.
    Notes: Mono-cyclopentadienylarsine (3a-e) werden durch Umsetzung von Cyclopentadienyl-trimethylsilan (1) oder Cyclopentadienyllithium (5) mit den Halogenarsinen 2a-e dargestellt. Sie sind äußerst luft- und feuchtigkeitsempfindlich und thermisch instabil. Es liegen σ-gebundene Cp-Liganden und Moleküle mit fluktuierender Struktur vor. Die Geschwindigkeit der entarteten metallotropen Umlagerungen wird durch die anderen Liganden am Arsenatom beeinflußt.
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  • 50
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1318-1328 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enehydrazines, 9. 1-Alkyl-3-hydroxypyrazoles from Hydrazones or HydrazinesReaction of dimethyl acetylendicarboxylate with hydrazinen oder Alkyl hydrazonen gives the methyl 1-alkyl-3-hydroxy-5-pyrazolecarboxylats 9 and 13a-e, subsequent saponification and decarboxylation gives the 1-alkyl-3-hydroxypyrazoles 11 and 15a-e. The cyclization of 13f to lactone 19a is a structure proff. Starting from benzaldehyde hydrazones, 2-pyrazoline-4,5-dicarboxylic esters are the main products.
    Notes: Durch Umsetzung von Acetylendicarbonsäure- dimethylester mit Hydrazinen oder Alkyl-hydrazonen erhält man die 1-Alkyl-3-hydroxy-5-pyrazolcarbonsäure-methylester 9 und 13a-e, durch Verseifung und Decarboxylierung hieraus die 1-Alkyl-3-hydroxypyrazole 11 und 15a-e. Die Cyclisierung von 13f zum Lacton 19a ist strukturbeweisend. Bei Verwendung von Benzaldehyd-hydrazonen entstehen hauptsächlich 2-Pyrazolin-4,5- dicarbonsäureester.
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  • 51
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1334-1343 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrophilic Addition of Disulfur Dichloride to Alkynes, 3. Reaction of Asymmetric of Asymmetric Substituted Alkynes with Disulfur DichlorideDisulfur dichloride adds to the triple bond of asymmetric substituted alkynes to afford vinyl sulfides, which are constitution isomers. Substituents R with a negative I-effect yield „Markownikof“ products whereas a positive I-effect leads to the formation of „anti-Markownikoff“ products. The addition is always trans. The obtained sulfides are oxidized with H2O2 in glacial acetic acid to yield the corresponding sulfones.
    Notes: Die bei der elektrophilen Addition von Dischwefeldichlorid an asymmetrische Alkine gebildeten Vinylsulfide sind Konstitutions -Isomere. Substituenten R mit negativem Induktionseffekt führen zu „Markownikoff“-Produkten, während ein positiver I-Effekt „anti-Markownikoff“-Orientierungen liefert. In allen Fällen erfolgt eine trans-Addition. Die erhaltenen Sulfide werden nach der Oxidation mit Wasserstoffperoxid/Eisessig als Sulfone isoliert.
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  • 52
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1371-1379 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Addition Reactions of Nitroalkanes to Tetrakis(triphenylphoshine)platinum(0)The oxidative addition of nitromethane to Pt(PPh3)4 in polar protic solution provides a convenient and safe method for the preparation of trans-(Ph3P) 2Pt(CNO)2 Pt(CNO2)(3). From Pt(PPh3)4 and nitromethane or 2-nitropropane cis-(Ph3P) 2Pt(NO2)2 (2) is obtained. The reactions of Pd(PPh3)4 or Rh(PPh3)2CO)Cl with CH3NO2 or some of its derivatives afford isocyanato compounds. Formaidoxime hydrochloride reacts with Pt(PPh3)4 to give trans-(Ph3P)2Pt-(CN)Cl (4).
    Notes: Die oxidative Addition von Nitromethan an Pt(PPH3)4 in polarem, protischem Medium liefert gefahrlos und in guter Ausbeute trans-(Ph 3P)2Pt(CNO)2 (3). Aus Pt(PPh3)4 und Nitromethan bzw. 2-Nitropropan wird cis-(Ph3P)2Pt(NO2)2 (2) erhalten. Die Umsetzungen von Pd(PPh 3)4 oder Rh(PPh3)2(CO)Cl mit Nitromethan oder Methylnitrolsäure führen zu Isocyanatoverbindungen. Formaldoxim-hydrochlorid reagiert mit Pt(PPh 3)4 zu trans-(Ph3P)2Pt(CN)Cl (4).
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  • 53
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1720-1730 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Botrydial, a Sesquiterpene Antibiotic from the Culture Solution of the Fungus Botrytis cinereaThe antibiotic botrydial (3) and its dihydro derivative (1) were isolated from the culture solution of the fungus Botrytis cinerea. Their structural formulas were elucidated by means of a series of chemical transformations together with the application of spectroscopic methods, especially a detailed analysis of the n.m.r. spectra. The basic skeleton of botrydial is a bicyclic, non-isoprenoid sesquiterpene system.
    Notes: Aus der Nährlösung des Pilzes Botrytis cinerea wurden das antibiotisch wirksame Botrydial (3) und sein Dihydroderivat (1) isoliert. Durch eine Folge chemischer Umwandlungen, verbunden mit der Anwendung spektroskopischer Methoden, insbesondere einer detaillierten Analyse der NMR-Spektren, wurden ihre Konstitutionsformeln abgeleitet. Botrydial liegt ein bicyclisch nicht-isoprenoides Sesquiterpenskelett zugrunde.
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  • 54
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1767-1768 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 55
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1773-1776 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occuring Terpene Derivatives, XXXVI. Synthesis of 8-Hydroxybrickellol and Dehydronerol isovalerateThe sesquiterpene 7 named 8-hydroxybrickellol as well as the isovalerate of dehydronerol (14) have been synthesized.
    Notes: Das 8-Hydroxybrickellol benannte Sesquiterpen 7 sowie der Isovaleriansäureester des Dehydronerols (14) werden synthetisch dargestellt.
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  • 56
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1420-1427 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reactions of Phosphorus Ylids with Excess Alkohol and AlkanethiolThe alkoxytetraalkylphosphoranes of the formula R4POR′, obtained from equimolar amounts of ylid and alkohol, which contain pentacoordinate phosphorus atoms, are converted into ionic products (1 - 7) by addition of excess alkohol. In these compounds phosphonium cations R4P⊕ are accompanied by hydrogen-bonded hydrogenalkoholate anions of the types [R′O…H…OR′]⊖, [H2(OR′)3]⊖, and [H3(OR′)4]⊖. This structure is proposed on the basis of n.m.r., i.r., and Raman-spectroscopic data. With ylids and alkanethiols only salt-like products R4P⊕RS⊖ are formed.
    Notes: Die aus äquimolaren Mengen von Yliden und Alkoholen zugänglichen, kovalent gebauten Alkoxytetraalkylphosphorane R4POR′ mit pentakoordinierten Phosphoratomen werden durch Addition von überschüssigem Alkohol in die Produkte 1 - 7 verwandelt, in welchen Phosphonium-Kationen R4P⊕ den wasserstoffbrückenverknüpften Hydrogenalkoholat-Anionen vom Typ [R′O…H…OR′]⊖, [H2(OR′)3]⊖ und [H3(OR′)4]⊖ gegenüberstehen. Der Strukturvorschlag stützt sich auf NMR-, IR- und Raman-spektroskopische Untersuchungen. Aus Yliden und Alkanthiolen entstehen nur die salzartigen Phosphonium-alkanthiolate R4 P⊕RS⊖.
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  • 57
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1472-1482 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of 3-Substituted Norbornanediazonium Ions3-Oxonorbornane-2-endo-diazonium ions (1), generated by acid-catalyzed decomposition of 3-diazonorcamphor (5) in alcoholic solutions, produce derivatives of endo-bicyclo[2.2.1]heptane 3 and bicyclo [3.1.1]heptane derivatives 4, varying with the nucleophilicity of the solvent. This suggests the 7-bridged ion 2 as intermediate, which plays also an important part in the deamination of 3,3-dimethoxynorcamphor tosylhydrazone (16) in alkaline solutions as shown by the formation of 3 and 4. In the alkaline deamination of 3,3- dimethoxy-5-norbornen-2-on tosylhydrazone (32) in methanol the homoallylic ion 34 is dominating.
    Notes: 3-Oxonorbornan-2-endo-diazonium-Ionen (1), erzeugt durch sauer katalysierte Zersetzung von 3-Diazonorcampher (5) in alkoholischen Lösungen, ergaben endo-Bicyclo[2.2.1]heptan-3 und Bicyclo[3.1.1]heptan-Derivate 4, deren Menge von der Nucleophilie des eingesetzten Lösungsmittels abhängig ist. Dies läßt das 7-verbrückte Ion 2 als Zwischenstufe vermuten, welches auch bei der Desaminierung des 3,3-Dimethoxynorcampher-tosylhydrazons (16) in alkalischen Lösungen eine entscheidende Rolle spielt, wie die Bildung der Produkte 3 und 4 beweist. Bei der alkalischen Desaminierung des 3,3-Dimethoxy-5-norbornen-2-on-tosylhydrazons (32) in Methanol ist jedoch die Homoallylumlagerung zum Kation 34 produkt-bestimmend.
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  • 58
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1536-1544 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Derivatives of Guanidines Containing Phosphorus and SulfurN-Chloroguanidines 1 react with tervalent phosphorous compounds or with sulfides to yield N-guanylphosphine imidium (3) or sulfimidium salts (9). Dehydrohalogenation gives the respective N-guanyl phosphine imides and sulfimides. The structure and reactions of these compounds are discussed.
    Notes: Die Umsetzung von N-Chlorguanidinen 1 mit tervalenten Phosphorverbindungen sowie Sulfiden führt zu N-Guanylphosphinimidium- (3) bzw. -sulfimidium-Salzen (9). Durch Dehydrohalogenierung werden die entsprechenden Phosphinimide und Sulfimide erhalten. Die Eigenschaften dieser Verbindungen - insbesondere die Struktur-und Bindungsverhältnisse-sowie ihre Reaktionen werden untersucht.
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  • 59
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1568-1578 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conformational Analysis, III. exo-Anomeric Effect and Circular Dichroism of Glycopyranosyl AzidesTetra-O-acetyl-aldopentopyranoses and penta-O-acetyl-aldohexopyranoses react readily with trimethylsilyl azide in the presence of BF3 or SnCl4 to afford the corresponding glycosyl azides 1a - 11 (table 1). Only the anomeric glycosyl azide having the azido group „trans“ to the 2-acetoxy group is obtained in each case. The polarization of the Cl—Nx and Nx—Nz bonds in glycosyl azides is such that in both cases the dipole is directed toward Nx. It can be deduced that glycosyl azides, like methyl glycopyranosides, should exhibit an exo-anomeric effect which strongly favors the conformers 9 and 12. The application of the azide-octant rule predicts a negative Cotton effect for the α-D-glycosyl azide 12 and a positive effect for the β-D-glycosyl azide 9. Circular dichroism measurements are in good agreement with these predictions, indicating the operation of an exo-anomeric effect in the glycosyl azides.
    Notes: Tetra-O-acetyl-pentopyranosen und Penta-O-acetyl-hexopyranosen setzen sich mit Trimethylsilylazid bei Gegenwart von BF3 oder SnCl4 leicht zu den entsprechenden Glycosylaziden 1a bis 11 um (Tab. 1). Es entsteht stets nur das anomere Glycosylazid, in dem die Azidogruppe und 2-OAc „trans“ zueinander angeordnet sind. In Glycosylaziden sind die Bindungen Cl—Nx und Nx—Nz in der Weise polarisiert, daß der Dipol in beiden Fällen zum Nx weist. Hieraus wird abgeleitet, daß bei Glycosylaziden wie bei Methylglycosiden ein exo-anomerer Effekt wirksam sein sollte, der die Konformeren 9 und 12 stark bevorzugt. Die Anwendung der Azid-Oktantenregel sagt für das α-D-Glycosylazid 12 einen negativen, für das β-D-Glycosylazid 9 einen positiven Cotton-Effekt voraus. Messungen des Circular-dichroismus stimmen mit diesen Voraussagen gut überein, was für einen exo-anomeren Effekt bei Glycosylaziden spricht.
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1645-1648 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermally Induced Reactions of Imidazole Derivatives, IV. Kinetics of the Thermal Rearrangement of 2,4,4-Triaryl-5-methylthio-4H-imidazolesThe thermal rearrangements of the title compounds 1a - d into the 2,4,5-triarylimidazoles 2 in different solvents and at different temperatures are first order reactions. No linear relation exists between the effect of the p-substituents of the migrating aryl groups on the reaction rates and their Hammett-Brown σ+ values. The solvent has practically no effect on the rearrangement rate of 1c. The activation parameters of the rearrangement 1c → 2c are given.
    Notes: Die thermische Umlagerung der Titelsubstanzen 1a - d in die 2,4,5-Triarylimidazole 2 in verschiedenen Lösungsmitteln und bei verschiedenen Temperaturen folgt einem Geschwindigkeitsgesetz 1. Ordnung. Der Einfluß des p-Substituenten der wandernden Arylgruppe ändert sich nicht linear mit den Hammett-Brownschen σ+-Werten. Das Lösungsmittel hat praktisch keinen Einfluß auf die Umlagerungsgeschwindigkeit von 1c. Die Aktivierungsparameter der Umlagerung 1c → 2c werden angegeben.
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  • 61
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1676-1683 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, 15. Preparation and Solvolysis of the Stereoisomeric 1-Bromomethylene-2-methylcyclopropanesThe stereoisomeric 1-bromomethylene-2-methylcyclopropanes (6Z and 6E) are synthesized and their solvolysis rates and products in ethanol/Water mixtures are determined. 6Z and 6E solvolyse at approximately the same rates. Both isomers yield only the rearranged products 12, 14, 16 and 18, which are formed from both isomers in the same ratio. The products as well as the kinetic data are explained by assuming the formation of the stabilized cyclopropylidenemethyl cation 7.
    Notes: Die stereoisomeren 1-Brommethylen-2-methylcyclopropane (6Z und 6E) wurden dargestellt und die Solvolysegeschwindigkeiten sowie die Produkte in Äthanol/Wasser-Gemischen bestimmt. 6Z und 6E solvolysieren dabei etwa mit gleicher Geschwindigkeit. Aus beiden Isomeren entstehen ausschließlich die umgelagerten Produkte 12, 14, 16 und 18 im gleichen Mengenverhältnis. Produktanalyse und Kinetik werden mit der Bildung des stabilisierten Cyclopropylidenmethylkations 7 erklärt.
    Additional Material: 2 Tab.
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  • 62
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1684-1701 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dispiro[2.0.2.4]deca-7,9-diene and Related Model Compounds: Synthesis, U.V, N.M.R, and Photoelectron-Spectroscopic InvestigationsDispiro[2.0.2.4]deca-7,9-diene (4) and spiro[2.5]octa-4,6-diene (5 can be obtained from the corresponding monoolefins 6 and 10, respectively, by bromine addition and subsequent dehydrobromination. The u. v. spectra of 5 and 4 with λmax = 269 nm (log ε = 3.4) and 284 nm (3.7), respectively, show bathochromic shifts of their longest wavelength bands as compared to 1,3-cyclohexadiene. An analysis of the 1H n. m. r. chemical shifts and H, H-coupling constants for the olefinic protons in 4 indicates that there is no cyclic electron delocalization in this ring system. The six-membered ring in 4 is only slightly flatter than the one in 1,3- cyclohexadiene. The photoelectron spectroscopic data of 4, 5, spiro[2.5]octane (13), spiro[2.5]oct-4-ene (15), dispiro[2.0.2.4]decane (14), and dispiro[2.0.2.4]dec-7-ene (16) demonstrate the effect of the interaction between π-orbitals and cyclopropyl Walsh-orbitals; an assignment for the first bands in the p. e. spectra of these compounds is proposed.
    Notes: Dispiro[2.0.2.4] deca-7,9-dien (4) und Spiro[2.5]octa-4,6-dien (5) lassen sich aus den entsprechenden Monoolefinen 6 bzw. 10 durch Bromierung und anschließende Dehydrobromierung gewinnen. Die UV-Absorptionen von 5 und 4 mit λmax = 269 nm (log ε = 3.4) bzw. 284 nm (3.7) sind bathochrom verschoben gegenüber denjenigen des 1,3-Cyclohexadiens. Aus einer Analyse der Chemischen Verschiebungen und H,H-Kopplungskonstanten der olefinischen Protonen im 1H-NMR-Spektrum von 4 ist zu schließen, daß 4 kein cyclisch delokalisiertes Elektronensystem enthält. Der Sechsring in 4 ist nur wenig stärker eingeebnet als derjenige im 1,3-Cyclohexadien. Anhand der Photoelektronen-Spektren von 4, 5 sowie Spiro[2.5]octan (13), Spiro[2.5]oct-4-en (15), Dispiro[2.0.2.4]decan (14) und Dispiro[2.0.2.4]dec-7-en (16) wird der Effekt der Wechselwirkung zwischen π-Orbitalen und Cyclopropyl-Walsh-Orbitalen aufgezeigt; für die jeweils ersten Banden in den PE-Spektren dieser Verbindungen wird eine Zuordnung vorgeschlagen.
    Additional Material: 4 Ill.
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  • 63
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1748-1763 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Hydrogenation with 1,4-Bis(dimethylamino)-(2S,3S)- and -(2R,3R)-butane-2,3-dio(DBD)/Lithium Aluminium HydrideThe diaminodiol 6 (DBD) mentioned inthe in the title is readily available in two steps from commercial diethyl tartrate. It reacts with lithium aluminium hydride (LAH) or deuteride to give chirally modified 1:1-complexes which reduce aldehydes, ketones, and ozonides to optically active carbinols in optical yields of up to 75%. Since both enantiomers of DBD are to accessible, both dextro- and levo-rotatory products may be prepared at will. DBD is easily separated from products and recovered without loss of activity. The (-)- DBD-LAH-complex reduces both dialkyl and aryl alkyl ketones to give samples enantiomerically enriched with carbinols of (S)- configuration, while the (+)-DBD-complex acts the other way around. This result is independent of the mode of preparation of the complex, of the ratio of reducing reagent over substrate, of addition of alcohols or water, of reaction temperature, or solvent. The effects of some of these influences upon the optical yields are large. Optimum conditions are given; the efficiency of the DBD-LAH-complex is compared with similar chirally modified LAH derivatives already known. A mechanism explaining the stereochemical results is proposed.
    Notes: Das aus Weinsäureester in zwei Stufen leicht zugängliche, im Titel genannte Diaminodiol 6 (DBD) setzt sich mit Lithiumaluminiumhydrid (LAH) und -deuterid zu chiral modifizierten 1: 1-Komplexen um. Diese reduzieren Aldehyde, Ketone und Ozonide zu opt. aktiven Carbinolen in optischen Ausbeuten bis zu 75%. Da beide Enantiomeren von DBD zugänglich sind, lassen sich gezielt (+)- oder (-)-drehende Produkte darstellen. DBD ist von den Produkten bequem abtrennbar und ohne opt. Verluste zurückgewinnbar. Mit (-)-DBD-LAH- Komplex entstehen Dialkyl- und Alkyl-aryl- carbinole mit (S)-, aus dem enantiomeren Komplex mit (R)-Konfiguration des Überschußenantiomeren. Dies ist völlig unabhängig von Darstellungsmodus des Komplexes, molarem Verhältnis von Reduktionsmittel und Substrat, Zusätzen von Alkoholen oder Wasser, Reaktionstemperatur oder -lösungsmittel. Die Einflüsse dieser Faktoren auf die opt. Ausbeuten, für die optimale Bedingungen angegeben werden, sind indessen zum Teil groß. Vergleiche mit bekannten Komplexen aus LAH und anderen chiralen Liganden werden gezogen. Es wird ein Vorschlag zur Erklärung der stereochemischen Befunde gemacht.
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  • 64
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1777-1779 
    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, XXXVII. Synthesis of the Sesquiterpene from Elvira biflora DCThe aromatic sesquiterpene 11 isolated from Elvira biflora DC has been synthesized starting with the p-cresol 2-butenyl ether (1).
    Notes: Das aus Elvira biflora DC isolierte aromatische Sesquiterpen 11 wird ausgehend vom p-Cresol-2-butenyläther (1) synthetisiert.
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  • 65
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1823-1834 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactivity of Nitrile Ylides of Different OriginThermolysis and photolysis of 2,3-dihydro- 1,4,2λ5-oxazaphospholes 2, photolysis of 1- azetines 3 as well as 1,3-elimination of hydrogen chloride from imidoyl chlorides 4 proceeds via the nitrile ylide intermediate 1. This is deduced from the same product ratio of the isomeric cycloadducts 5:6 on trapping with acrylic acid esters.
    Notes: Die Thermolyse und Photolyse von 2,3-Dihydro-1,4,2λ5-oxazaphospholen 2, die Photolyse von 1-azetine 3 wie auch die 1,3-Eliminierung von Chlorwasserstoff aus Imidoylchloriden 4 verläuft über die Nitril-ylid-Zwischenstufe 1. Dies wird aus dem jeweils gleichen Produkt-verhältnis der isomeren Cycloaddukte 5:6 bei der Abfangreaktion mit Acrylsäureestern abgeleitet.
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  • 66
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1903-1914 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,8-Di-tert-butyl-[9-13C]-9-fluorenyl, Bis(2-tert-butylphenyl)[α-13C]methyl and their DimersThe preparation of the title compounds is reported. The 1H n. m. r. spectra of the dimers of 1 and [9-13C]-1, respectively, yield the cyclohexadiene structure 12 for the dimer. The 1H n. m. r. spectrum of [α-13C]-2 dimer confirms structure 1411). The e. s. r. results of 1 and 2 are discussed.
    Notes: Die Darstellung der Titelverbindungen wird beschrieben. Die 1H-NMR-Spektren der Dimeren von 1 bzw. [9-13C]- 1 ergeben die Cyclohexadien-Struktur 12 für das Dimere. das 1H-NMR-Spektrum des [α-13C]- 2-Dimeren bestätigt die Struktur 14 11). Die ESR-Ergebnisse (a(H) und a(13C)) von 1 und 2 werden diskutiert.
    Additional Material: 3 Ill.
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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: Photochemistry of Small Rings, 30. Photochemistry of β,γ-Unsaturated Aldehydes.  -  Mechanism of the Photofragmentation of Phenyl-substituted CyclopentenecarbaldehydesA new synthesis of β,γ-unsaturated cyclopentenecarbaldehydes 1 by thermolysis of bicyclo-[3.1.0]hexenols 13 is described. Photolysis of the aldehydes 1 in benzene solution affords the cis-configurated cyclopentenes 2 in good yields. Cyclopentaphenanthrenes 16 are isolated as byproducts. 2 undergoes an electrocyclic reaction to form 17, which is then dehydrogenated to 16. The quantum yields of the photofragmentation and -cyclization are Φ2 = 0.23 and Φ16 = 0.07, respectively. From the emission spectra of 1a the energy of the singlet and triplet state is calculated to ES1 = 84.1 and ET1 = 62.2 kcal/mole. The kinetics of photoreactions 1 → 2 → 16 are studied using ED- and EDQ-diagrams. Sensitization studies demonstrate that the photoreaction 1 → 2 can also occur via a triplet state, but with reduced effectivity. Since quenching with piperylene is ineffective the reaction 1 → 2 very probably involves predominantly an n-π-singlet state. The mechanism proposed for the stereospecific, intramolecular reaction 1 → 2 involves the formation of a formyl allyl radical as a main intermediate.
    Notes: Eine neue Synthese von β,γ-ungesättigten Cyclopentencarbaldehyden 1 durch Thermolyse von Bicyclo [3.1.0]hexenolen 13 wird beschrieben. Die Photolyse der Aldehyde 1 in Benzol ergibt in guten ausbeuten die cis-konfigurierten Cyclopentene 2 und als Nebenprodukte die Cyclopentaphenanthrene 16.2 geht durch elektrocyclischen Ringschluß in 17 über, das unter Dehydrierung in 16 umgewandelt wird. Die Quantenausbeuten der photofragmentierung bzw. -cyclisierung betragen Φ2 = 0.23 bzw. Φ16 = 0.07. aus den Emissionsspektren von 1a wird die Energie von singulett- und Triplett-Zustand zu ES1 = 84.1 bzw. ET1 = 62.2 kcal/mol errechnet. Die Kinetik der Photoreaktionen 1 → 2 → 16 wird mit Hilfe von Ed- und EDQ-Diagrammen näher studiert. Wie Sensibilisierungsstudien zeigen, kann die Photoreaktion 1 → 2, wenn auch mit geringerer Effektivität, über einen Triplett-Zustand verlaufen. Sie läßt sich mit Piperylen nicht löschen, weshalb die Reaktion 1 → 2 weitgehend über einen angeregten n-π-S1-Zustand formuliert wird. Für den Mechanismus der stereospezifischen, intramolekularen (D-Markierung) Reaktion 1 → 2 wird ein Formyl-Allyl-Radikalpaar als Wesentliche Zwischenstufe vorgeschlagen.
    Additional Material: 7 Ill.
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  • 68
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1882-1890 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties, XXXIV. CyanamideThe PE spectrum of cyanamide is easily assigned by comparison with that of the isoelectronic acetonitrile. The orbital sequence obtained is supported by vibrational fine structures, by the PE spectrum of dimethylcyanamide, and by CNDO calculations. Furthermore, the calculated charge densities render possible an appreciation of properties of cyanamide and its alkyl derivatives.
    Notes: Das PE-Spektrum von Cyanamid läßt sich durch Vergleich mit dem des isoelektronischen Acetonitrils zwanglos zuordnen. Die so abgeleitete Orbitalreihenfolge wird durch Schwingungsfeinstrukturen, das PE-Spektrum von Dimethylcyanamid sowie durch CNDO-Rechnungen gestützt. Die berechneten Ladungsdichten erlauben darüber hinaus. Eigenschaften von Cyanamid und seinen Alkylderivaten zu verstehen.
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  • 69
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1915-1924 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Condensed Ring Systems, VI. Synthesis of [4.2.2]Propella-7,9-diene, a Dewar Benzene Bridged in 1,4-PositionThe reaction of 8,11-dithia [4.3.3] propellane (1, n = 4) with N-chlorosuccinimide and monoperphthalic acid yields a mixture of four isomeric dichlorinated disulfones (2, n = 4). The major isomer 7 is formed in 40% yield. Upon treatment of 2 (n = 4) with potassium tert-butoxide at low temperatures [4.2.2] propella-7,9-diene2) (3, n = 4) is obtained. The constitution of 3 (n = 4) is deduced by 1H and 13C n. m. r as well as mass spectrometry.
    Notes: Die Umsetzung des 8,11-Dithia [4.3.3] propellans (1, n = 4) mit N-Chlorsuccinimid und Monoperphthalsäure führt zu einem Gemisch von vier isomeren dichlorierten Disulfonen (2, n = 4), von denen das Hauptprodukt 7 in 40proz. Ausbeute entsteht. 2 (n = 4) läßt sich mit Kalium-tert-butylat bei tiefen Temperaturen in das [4.2.2]Propella-7,9-dien2)(3, n = 4) überführen, dessen Konstitution durch die 1H-, 13C-NMR- und Massenspektren bewiesen wird.
    Additional Material: 6 Ill.
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  • 70
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 1988-1997 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoisomerisation Reactions in Bicyclo[3.2.2]nona-6,8-diene DerivativesFrom the photochemical behavior of suitably substituted derivatives (dicarboxylic ester 3a, dicarboxylic acid 3b, bis(trifluoromethyl)-derivative 3c) it is concluded, that in the bicyclo-[3.2.2]nona-6,8-diene skeleton 1 (n = 3) the [2π + 2π]-Cycloaddition to 2 (n = 3) neither by direct nor by sensitized excitation takes place. Instead 1,3-alkyl shift (3a → 6a) and di-π-methane-rearrangement 3a → 7a, 3c → 8c) are observed. Arguments for this behavior differing from the lower homologues 1 (n = 0, 1, 2) are discussed.
    Notes: Aus dem photochemischen Verhalten geeignet substituierter Derivate (Diester 3a, Dicarbonsäure 3b, Bis-trifluormethyl-Derivat 3c) wird geschlossen, daß im Bicyclo[3.2.2]nona-6,8-dien-Gerüst 1 (n = 3) die [2π + 2π]-Cycloaddition zu 2 (n = 3) weder bei direkter noch bei sensibilisierter Lichtanregung stattfindet. Als Ersatzreaktionen werden 1,3-Alkylverschiebung (3a → 6a) und Di-π-Methanumlagerung (3a → 7a, 3c → 8c) beobachtet. Gründe für dieses von den niedrigeren Homologen 1 (n = 0, 1, 2) abweichende Verhalten werden diskutiert.
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  • 71
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: PFT-13C-N.M.R. and Mass Spectra of Heterocycles.  -  1,2-Diazaspiro[4.4]nonatetraenesl Azaindolizines, and 3aH-Indazoles13C n.m.r. spectra obtained by the pulse Fourier transform method of 1,2-diazaspiro[4.4]-nonatetraenes 1, azaindolizines 2, and 3aH-indazoles 3 are described. A combination of highest and lowest field resonances allows an unambigous distinction between 1 and 2. A similiar approach is suggested for 3. Estimated increments from model compounds agree well with the c.m.r. spectra. „Strickspektren“ demonstrate the effect of the substituents on the chemical shift of 1 - 3. The mass spectra of 1 - 3 are discussed briefly.
    Notes: Die mit der Puls-Fourier-Transform-Methode erhaltenen 13C-NMR-Spektren von 1,2- Diazaspiro[4.4]nonatetraenene 1, Azaindolizinen 2 und 3aH-Indazolen 3 werden beschrieben. aus einer Kombination von Höchst-und Tiefstfeld-Resonanzfrequenzen konnten die Strukturen 1 und 2 eindeutig unterschieden werden. Eine entsprechende Analyse wurde für 3 vorgenommen. Inkrementabschätzungen führten zu meist guter Übereinstimmung mit den gemessenen Spektren. Aus den Strichspektren kann der durch die verschiedenen Substituenten hervorgerufene Einfluß auf die chemischen Verschiebung von 1 - 3 werden kurz diskutiert.
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2120-2122 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 73
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2095-2114 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substituenteffects in Pericyclic Reactions: The Cycloheptatriene-Norcaradiene-Problem, investigated in C-7-Monosubstituted CompoundsCharacteristic features of the cycloheptatriene-norcaradiene potential curves can be simulated by using methyl cations, which are stabilized by heterofunctional groups and bound to C-7: 1. The potential curve corresponding to low energy cycloheptatriene is realized for the 7-bis(alkylamino)methyl cation 9a 2. Cycloheptatriene and norcaradiene are energetically comparable in the case of the 7-alkoxy(amino)methyl cations. At room temperature 9b - e and 10b - e form a fast dynamic equilibrating system. 3. Norcaradiene 10f comprises the lower minimum of the potential curve for the 7-(1,3-dioxolan-2-ylium) cation. In 10f the substituent is in the exo-position. Using variable temperature 1H-n.m.r., thermodynamic parameters are determined for the equilibria 9b - e ⇋ 10b - e. The influence of C-7-substituents on the cycloheptatriene-norcaradiene equilibrium is discussed and visualized using the MO-model.
    Notes: Methylkationen, stabilisiert durch nachbarständige Alkoxy-oder Alkylaminogruppen und gebunden an C-7, ermöglichen es, drei charakteristische Lagen des Cycloheptatrien-Norcaradien-Gleichgewichtes zu simulieren: 1Mit energieniedrigem Cycloheptatrien-Niveau im 7-Bis(alkylamino)methyl-Kation 9a.2Mit nahezu energiegleichen Cycloheptatrien- und Norcaradien-Grundzuständen in den 7-Alkoxy(amino)methyl-Kationen 9b-e ⇋ 10b - e. 3. Mit energieniedrigem Norcaradien-Grundzustand in der 7-(1,3-Dioxolan-2-ylium)-Verbindung 10f. In 10f ist der Substituent exo-ständig. Thermodynamische Daten der schnellen und reversiblen Gleichgewichte 9b - e ⇋ 10b - e werden bestimmt. Die C-7-Substituentenbeeinflussung des Cycloheptatrien-Norcaradien-Gleichgewichtes wird diskutiert und durch das MO-Modell beschrieben.
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2169-2175 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Easy Way for the Preparation of Organylfluorophosphoranes RnPF5-nOrganylfluorophosphoranes can easily be synthesized by reaction of phosphines or chlorophosphines with CCl4 and HF-donors, especially phenylcarbamoyl fluoride.
    Notes: Eine einfache Synthese der Organylfluorphosphorane beruht auf der Umsetzung von Phosphinen und Chlorphosphinen mit CCl4 und HF-Donatoren, vorzugsweise Phenylcarbamoyl-fluorid.
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  • 75
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2215-2237 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyclopropenones with enamines, 2. Methylphenyl- and Phenylcyclopropenone and EnaminesThe reaction of methyphenylcyclopropenone (2) with enamines 4a-d and phenycyclopropenone (3) with enamines 4a, c, h at 20°C leads to 2-azoniabicyclo[3.1.0]hex-3-en-3-olates 6, which are isomerized thermally to 2,4-pentadienamides 8. These are also formed directly from 2, 3 and enamines 4 at 80 °C and are accompained in some cases (enamines 4g, h) by β-enaminoketones (5a - c). The constitution and configuration of these „1:1-adducts“ is derived from spectral and chemical evidence. The reaction of 3 with enamines 4 yields as main products „2:1-adducts“ for which the structure of spiro-lactones 20, 21 is assumed on the basis of spectroscopic and chemical data. Some aspects of the mode of formation of these products are discussed.
    Notes: Die Reaktion von Methylphenylcyclopropenon (2) mit den Enaminen 4a - d und Phenyl-cyclopropenon (3) mit den Enaminen 4a, c, h bei 20 C führt zu 2-Azoniabicyclo[3.1.0]hex-3-en-3-olaten 6, die thermisch zu 2,4 -Pentadienamiden 8 isomerisieren. Diese werden bei 80 °C auch direkt aus 2,3 und Enaminen 4 gebildet und sind in einigen Fällen (Enamine 4g, h) von β-Enaminoketonen (5a-c) begleitet. Konstitution und Konfiguration dieser „1:1-Addukte“ wird aus spektroskopischen Kriterien und chemischen Reaktionen abgeleitet. Bei der Umsetzung von 3 mit Enaminen 4 entstehen als Hauptprodukte „2:1-Addukte“ für die aufgrund spektroskopischer und chemischer Befunde die Struktur von Spirolactonen 20, 21 anzunehmen ist. Einige Aspekte zum Bildungsmechanismus dieser Produkte werden diskutiert.
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  • 76
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2186-2214 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Cyclopropenones with Enamines, 1 Diphenylcyclopropenone and EnaminesDiphenylcyclopropenone (1) reacts with the enamines 9 at 0-20°C to yield the 2-azoniabicyclo[3.1.0]hex-3-en-3-olates 10, whereas at 80°C the main products of the reaction are the 2,4-pentadienamides 25; compounds 10 are isomerized to the amides 25 at 20°C. The structure of the betaines 10 is deduced from their spectral data, their C-protonation (leading to 17), their O-alkylation (leading to 19), and their ring opening reactions with nucleophiles such as water, alcohols, and amines (leading to 20, 23, 24). The structure of the amides 25 is proven by means of spectral data and independent synthesis of the tetrahydro derivatives 26. The reaction of 1 with some enamines 9 produces as by-products the β-enamino ketones 30 and α-amino cyclopentenones 31, which are isomeric with 25. Their structure is confirmed by means of spectra and chemical degradation reactions. Some aspects of the mechanism of the reaction of diphenylcyclopropenone with enamines are discussed on the basis of the constitution of the products 10, 25, 30, and 31.
    Notes: Die Reaktion von Diphenyclyclopropenon (1) mit den Enaminen 9 führt bei 0-20°C zu den 2- Azoniabicyclo[3.1.0]hex-3-en-3-olaten 10, bei 80°C zu den 2,4-Pentadienamiden 25 als Hauptprodukten die Verbindungen 10 werden bei 80°C zu den Amiden 25 isomerisiert. Die Struktur der Betaine 10 wird aus ihren spektroskopischen Daten, ihrer C-Protonierung (zu 17), ihrer O-Alkylierung (zu 19) und ihrer Ringöffnung mit nucleophilen Agentien wie Wasser, Alkoholen und Aminen (zu 20, 23, 24) bewiesen. Der Konstitutionsbeweis der Amide 25 wird über ihre Spektren und über die unabhängige Synthese von Tetrahydroderivaten 26 geführt. Als Nebenprodukte der Reaktion von 1 mit einigen Enaminen 9 werden zu 25 isomere β-Enaminoketone 30 und α-Aminocyclopentenone 31 isoliert. Deren Konstitution wird durch Spektren und Abbaureaktionen gesichert. Aufgrund der ermittelten Konstitutionen 10, 25, 30, 31 werden einige Aspekte des Mechanismus der Reaktion von Diphenylcyclopropenon mit Enaminen erörtert.
    Additional Material: 8 Tab.
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  • 77
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2284-2294 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Synthesis of Purinenucleoside-6-sulfonates6(1H)-Purinethone-9-(β-D-ribofuranosid) (1), the corresponding 5′-monophosphate 7, and the 5′-triphosphate 8 as well as 2-amino-6(1H)- purinethione-9-(β-D-ribofuranoside) (2) and 2-amino-6(1H)-purinethione-9-(β-D-2′-deoxyribofuranoside) (3) have been converted to the sulfonates 4,9,10,5, and 6 by reaction with sulfite ions in the presence of oxygen. The sulfonates 4 and 5 reacted in aqueous ammonia with good yields to give adenosine and 2,6-diaminopurine-9-(β-D-ribofuranoside), respectively. 4 and 9 react with aziridine to form 6-(1-aziridinyl)purine-9-(β-D-ribofuranoside) (15) and the corresponding 5′-monophosphate 16. 5 and 6 fluoresce with high quantum yields on excitation in the near u. v. It was shown by means of fluorescence spectroscopy, absorption spectroscopy, and comparison with authentic material that irradiation of 1, 2 and 3 by light of the wavelength 235 nm in the presence of oxygen affords the purinenucleoside-6-sulfonates 4, 5 and 6.
    Notes: 6(1H)-Purinthion-9-(β-D-ribofuranosid) (1), das entsprechende 5′-Monophosphat (7) und 5′-Triphosphat (8) sowie 2-Amino-6(1H)-purinthion-9-(β-D-ribofuranosid) (2) und 2-Amino-6(1H)-purinthion-9-(β-D2′-desoxyribofuranosid) (3) wurden durch Reaktion mit Sulfitionen in Gegenwart von Sauerstoff quantitativ in die entsprechenden Sulfonsäurederivate 4,9,10,5,6 übergeführt. Die Sulfonate 4 und 5 ließen sich bei Raumtemperatur mit wäßrigem Ammoniak in guten Ausbeuten zu Adenosin bzw. 2,6-Diaminopurin-9-(β-D-ribofuranosid) umsetzen. 4 und 9 reagierten mit Aziridin zu 6-(1-Aziridinyl)purin-9-(β-Dribofuranosid) (15) bzw. dem 5′-Monophosphat 16. 5 und 6 fluoreszieren mit hoher Quantenausbeute im langwelligen ultravioletten Licht. Mit Hilfe der Fluoreszenzspektroskopie, Absorptions-spektroskopie und durch Vergleich mit authentischem Material konnte die Bildung der Purinnucleosid-6-sulfonate 4, 5 und 6 auch bei der Bestrahlung von 1, 2 und 3 mit Licht der Wellenlänge 325 nm in Gegenwart von Sauerstoff nachgewiesen werden.
    Additional Material: 2 Ill.
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  • 78
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2326-2328 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 2-Propyl-cis-perhydroquinolin-5α-olReaction of 1,3-cyclohexanedione with 1-chloro-3-hexanone (2), followed by reductive amination yields 2-propyl-1,2,3,4,5,6,7,8-octahydro-5-quinolinon (4). On hydrogenation with Pt in acetic acid 2-propyl-cis-perhydroquinolin-5α-ol (5) is obtained.
    Notes: Ausgehend von 1,3-Cyclohexandion wurde durch Umsetzung mit 1-Chlor-3-hexanon (2) und nachfolgende reduktive Aminierung das 2-Propyl-1,2,3,4,5,6,7,8-octahydro-5-chinolinon (4) erhalten. Hieraus entsteht bei der Hydrierung mit Pt in Eisessig 2-Propyl-cis-perhydrochinolin-5α-ol (5).
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  • 79
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 2345-2361 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies of Electron-Depleted Thiocarbonyl Compounds, 2. Trithiocarbonate S,S-DioxidesEleven trithiocarbonate S,S-dioxides 1 were prepared by treatment of chlorodithioformates with sulfinic acid salts and their properties investigated. In the reaction of methyl chlorodithioformate with sodium methanesulfinate, methyl (methylsulfonyl)(methylthio)methyl trithiocarbonate (4a) is formed instead of the expected 1. Compounds 4 can also be obtained by reduction of 1 with sulfinates, thiophenols, or tetrabutylammonium borohydride. Sodium diethyl methylmalonate is thioacylated by S′-phenyl S-p-tolyl trithiocarbonate S,S-dioxide (1i) to yield diethyl methyl(phenylthiothiocarbonyl)malonate(13), while the less bulky phenyllithium attacks 1i in a nucleophilic manner at the thiono sulfur to yield S′,S″-diphenyl S-p-tolyl trithioorthoformate S,S-dioxide (15). Inverse addition of Grignard solutions to 1 produces the 1-sulfonyl -1,2,2-trithioethylenes 19.
    Notes: Durch Umsetzung von Chlordithioformiaten mit Sulfinsäuresalzen wurden elf Trithiocarbonat-S.S-dioxide 1 dargestellt und auf ihre Eigenschaften untersucht. Bei der Umsetzung von Methyl-chlordithioformiat mit Natrium-methansulfinat bildet sich statt des erwarteten 1 Methyl-[(methylsulfonyl)(methylthio)methyl]-trithiocarbonat (4a). Die Verbindungen 4 erhält man auch bei der Reduktion von 1 mit Sulfinaten, Thiophenolen oder Tetrabutylammoniumboranat. Natrium-methylmalonsäure-diäthylester wird von S′-Phenyl-S-p-tolyl-trithiocarbonat-S,S-dioxid (1i) zu Methy(phenylthiothiocarbonyl)malonsäure-diäthylester (13) thioacyliert, während das weniger sperrige Phenyllithium 1i nucleophil am Thionschwefel unter Bildung von S′.S″-Diphenyl-S-p-tolyl-trithioorthoformiat-S,S-dioxid (15) angreift. Inverse Addition von Grignard -Verbindungen an 1 führt zu den 1-Sulfonyl-1,2,2-trithioäthylenen 19.
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  • 80
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Dicarboxylic Acid Esters, III. Reaction of Dimethyl 4,5-Dihydro-2,3-furandicarboxylates with 1,2-Diamines.  -  Synthesis of 3-(5-Alkyl-2-2oxotetrahydro-3-furanylidene)-2-quinoxalinones, -2-pyrazinones, and -1,4-diazepine-2-onesTreatment of the dihydrofurandicarboxylic acid esters 4a-c with 1.2-diamines does not result in normal ester aminolysis but in ring cleavage followed by lactonization. According to the diamine used the quinoxalinones 14, 15a-c, the pyrazinones 11-c, and the diazepinones 16a, c are obtained. The independent synthesis of the compounds 11a, 14a, 15a by condensation of the different diamines with α-ethoxalyl-γ-butyrolactone as well as the tabulated i. r. and n. m. r. data confirm the proposed structures.
    Notes: Dihydrofurandicarbonsäureester vom Typ 4a-c reagieren mit 1,2-Diaminen nicht im Sinne einer normalen zweifachen Ester-Aminolyse, sondern unter Ringöffnung und anschließender Lactonisierung. Entsprechend dem eingesetzten Diamin erhält man die Chinoxalinone 14.15a-c, die Pyrazinone 11a-c sowie die Diazepinone 16a, c. Die unabhängigen Synthesen der jeweiligen Grundkörper 11a, 14a, 15a durch Kondensation der verschiedenen Diamine mit α-Äthoxalyl-γ-butyrolacton, wie auch die aufgeführten IR- und NMR-Daten bestätigen die angenommenen Strukturen.
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  • 81
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3053-3069 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Unusual Course of an Acetal Hydrolysis during a Synthesis of HomotropilideneAcetals 3a-c are synthesized by Diels-Alder reaction of cyclopropene and 1-methyleyclopropene with tetrachlorocyclopentadienone acetals. Dechlorination of the adducts leads to the acetals 4a-c; their reaction with diazomethane yields 8a-c. Hydrolysing the acetals 8a, b the ketone 9 (35%) and a rearranged product 10 (65%) are formed. The hydrolysis of the acetal 8c gives only the rearranged products 11a-c. The constitution and the stereochemistry of all new products is confirmed by 1H and 13C n.m.r. spectroscopy, in the case of alcohol 11a by using Eu(fod)3 as a shift reagent. The mechanism of the hydrolysis is explained by the nature of the intermediate carbenium-oxonium ion and its steric shielding by the exo-cyclopropane ring.
    Notes: Durch Diels-Alder-Reaktion von Cyclopropen bzw. 1-Methylcyclopropen mit Tetrachlor-cyclopentadienon-acetalen werden die Acetale 3a-c erhalten. Die Dechlorierung der Addukte liefert die Acetale 4a-c, deren Homologisierung mit Diazomethan zu den tetracyclischen Acetalen 8a-c führt. Durch Hydrolyse der Acetale 8a, b entsteht zu 35% das Keton 9 und zu 65% ein Umlagerungsprodukt der Struktur 10. Je nach den angewandten Bedingungen lassen sich bei der Hydrolyse des Acetals 8c nur Umlagerungsprodukte 11a-c isolieren. Die Konstitution und Stereochemie der neuen Verbindungen wird durch 1H- und 13C-NMR-Spektroskopie, z. T. unter Anwendung von Lanthanoiden-Shift-Reagenzien, gesichert. Der Hydrolysenmechanismus wird über das intermediäre Carbenium-Oxonium-Ion und dessen sterische Abschirmung durch den exo-Dreiring erklärt.
    Additional Material: 2 Ill.
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  • 82
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3113-3120 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, LXVII. Silaborazines from CyclosilazanesPhenyldichloroborane reacts with [(CH3)2SiNH]3 (5) to yield the disilaboranine 8, the monosilaborazine 7, and/or B,B′, B″-triphenylborazine (9), depending on the ratio of the reactants. Reaction with octamethylcyclotetrasilazane, [(CH3)2SiNH]4 (12), in a 1:1 molar ratio leads to NH4Cl, 8, and a polymer. Product analysis shows that only part of 8is formed by direct SiN-cleavage, the other part results from a substitution leading to NH4Cl.
    Notes: Phenylbordichlorid reagiert je nach Molverhältnis mit [(CH3)2SiNH]3 (5) zum Disilaborazin 8, Monosilaborazin 7und/oder B,B′, B″-Triphenylborazin (9). Bei der Umsetzung mit Octamethylcyclotetrasilazan, [(CH3)2SINH] 4 (12), im Molverhältnis 1:1 entstehen NH4Cl, 8 und Polymere. Aus der Stoffbilanz folgt, daß nur ein Teil von 8über direkte Silazanspaltung entstehen Kann; der andere ist die Folge einer zu NH4Cl führenden Substitutionsreaktion.
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  • 83
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3149-3151 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 84
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3155-3163 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Mechanism of Desulfuration of 1,3-Benzodithiole-2-thione with Triethyl PhosphiteThe reaction of title compound 1 with triethyl phosphite in the presence of capture-reagents is investigated. With alcohols the reaction yields 12 and 13, with piperidine 17, with carbonyl compounds 20-23, and with enamines 24. The results are explained by a thiophilic attack of triethyl phosphite on 1 with generation of the 1,3-dipole 14 and subsequent reactions.
    Notes: Die Reaktion der Titelverbindung 1 mit Triäthylphosphit in Gegenwart von Abfangreagentien wird untersucht. Mit Alkoholen werden 12 und 13, mit Piperidin 17, mit Carbonylverbindungen 20-23 und mit Enaminen 24 erhalten. Die Ergebnisse werden mit einem thiophilen Angriff des Phosphits auf 1 unter Bildung des 1,3-Dipols 14 und dessen Folgereaktionen erklärt.
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  • 85
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3186-3190 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substitution Reactions at Tin- and Silicon-containing Compounds[(CH3)3Sn]3N reacts with the silicon chlorides (CH3)3SiCl, (CH3)3 2SiCl2, CH3SiCl3, and SiCl4 under cleavage of a Sn—N bond to form the compounds 1-4. 2 and 3 react with AgNCO und AgNCS to yield the corresponding pseudohalides 5-8. The behaviour of [(CH 3)3Sn]3N, 1, 2, 3 and 7 towards S4N4 is investigated; the new sulfur diimides 9 and 10 could be isolated.
    Notes: [(CH3)3Sn]3N reagiert mit den Silylchloriden (CH 3)3SiCl, (CH3)3 2SiCl2, CH3SiCl3 und SiCl4 unter spaltung einer Sn—N-Bindung. Dabei bilden sich die Verbindungen 1-4. Bei der Umsetzung von 2 und 3 mit AgNCO und AgNCS entstehen die entsprechenden Pseudohalogenide 5-8. Das Verhalten von [ CH3)3Sn]3N, 1, 2, 3 und 7 gegenüber S4N4 wird untersucht. Dabei Konnten die neuen Schwefeldiimide 9 und 10 isoliert werden.
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  • 86
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3222-3236 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Complexes of N-Containing Ligands, VII. Arenedicarbonylchromium Complexes of the Type ArCr(CO)2L Containing 2,3-Diazabicyclo[2.2.1]hept-2enePhotolysis of arenetricarbonylchromium complexes, ArCr(CO)3 (1), in the presence of 2,3- diazabicyclo[2.2.1]hept-2-ene (az, 2) in THF solution has been used to prepare compounds of the type ArCr(CO)2(az) (3). Nine complexes (3a-i) containing differently substituted benzene ligands Ar have been isolated and characterized on the basis of their i.r. and 1H-n.m.r. spectra. The bicyclic azo compound 2 is unsymmetrically coordinated to the metal through the lone pair of electrons of one of the nitrogen atoms of the N=N double bond. The temperature dependence of the 1H-n.m.r. spectra indicates an intramolecular mobility of the azo ligand in the complexes 3 which is frozen out at room temperature. Hammett correlations point to electronic ligand-ligand interactions between the π-bonded benzene ring Ar and both the two CO groups and the azo ligand az in these ArCr(CO)2(az) complexes.
    Notes: Durch Photolyse von Aromat-tricarbonylchrom-Komplexen, ArCr(CO)3 (1), in Gegenwart von 2,3-Diazabicyclo [2.2.1]hept-2-en (az, 2) in THF-Lösung lassen sich Verbindungen des Typs ArCr(CO)2(az) (3) erhalten. Neun Komplexe (3a-i) mit verschieden substituierten Benzol-Liganden Ar wurden dargestellt und anhand ihrer IR- und 1H-NMR-Spektren charakterisiert. Die bicyclische Azoverbindung 2 ist unsymmetrisch über ein Stickstoffatom der N=N-Doppelbindung an das Zentralmetall koordiniert. Aus der Temperaturabhängigkeit der 1H-NMR-Spektren kann auf eine intramolekulare Bewegung des Azoliganden in den Komplexen 3 geschlossen werden, die bei Raumtemperatur eingefroren ist. Mit Hilfe von Hammett-Korrelationen läßt sich zeigen, daß in den Komplexen 3 der π-gebundene Sechsring Ar sowohl mit den beiden CO-Gruppen als auch mit dem Azoliganden az in elektronischer Wechselwirkung steht.
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  • 87
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3043-3052 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Systematic Investigation of the Reaction Conditions for the Phosphorylation 5′-Amino-5′-deoxyguanosine CompoundsReaction conditions for the phosphorylation of 5′-amino-, 5′-Amino-2′,3′-isopropylidene-, and 5′-butylamino- 5′-deoxyguanosine (1a,b,c respectively) with diesters of phosphorochloridic acid have been systematically investigated and the dependence of the reaction on reagent, solvent, tertiary base and guanosine derivative has been determined. A new, generally applicable phosphorylating system employing a diester of phosphorochloridic acid, N,N- diiso-propylethylamine and triethylphosphate (or dimethylformamide) is described.
    Notes: Die Phosphorylierungsbedingungen für 5′-Amino-, 5′-Amino-2′,3′-isopropyliden- bzw. 5′- Butylamino-5′-desoxyguanosin (1a, b bzw. 1c) mit Phosphorsäurediesterchloriden wurden systematisch untersucht und eine Abhängigkeit von allen Reaktionsparametern wie Reagenz, Lösungsmittel, tertiärer Hilfsbase und Guanosinderivat festgestellt. Ein neues generell geeignetes Phosphorylierungssystem, bestehend aus Phosphorsäurediesterchlorid, N,N-Diiso-propyläthyiamin und Triäthylphosphat bzw. Dimethylformamid, wurde gefunden.
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  • 88
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nuclear Magnetic Resonance Studies on Boron Compounds, VIII Comparison of 11B and 14N N.M.R. Data of Tervalent Boron Compounds with 13C and 14N N.M.R. Data of Derivatives of Carbonic Acids and Carbonium IonsThe δ14N data of N-methylureas, -carbamates, -acetamide, and -diacetamide correlate linearly with the δ δ14N data of the isosteric aminoboranes B[N(CH3)2]3, (CH3B[N((CH3)2]2, and (CH3)2-BN(CH3)2. The same is true for the series of the guanidinium, amidinium, and imonium ions and the corresponding isoelectronic aminoboranes. A comparison of δ13C and δ11B n.m.r. chemical shifts for the first series of compounds only shows a trend towards low field shift as the positive charge at the respective atoms increases. However, in the case of carbonium ions and isoelectronic boranes there is a linear relationship between δ 13C and δ11B, as given by the equation δ 11B = 0.393 δ 13C - 30.73. From the data δ 11B = -70.0 ppm is deduced for monomeric BH3.
    Notes: Die δ14N-Werte von N-Methyliertem Harnstoff, Carbamidsäureester, Acetamid und Diacetamid stehen mit den δ14N-Daten der isosteren Aminoborane B[N(CH3)2]3, CH3B[N(CH3)2]2 und (CH3)2BN(CH3)2 in linearer Beziehung. Dies gilt auch für die Reihe der Guanidinium-, Amidinium- und Imonium-Ionen und die mit ihnen isoelektronischen aminoborane. Ein Vergleich der δ13C- und der δ11B-Daten für die erste Verbindungsreihe spiegelt zwar die zunehmende positive Ladung am betrachteten Zentrum  -  allerdings nur im Trend - wieder, da keine lineare Korrelation erkennbar ist. Diese 1st. Diese ist jedoch für die Reihe der Carbonium-Ionen und Borane gegeben. Es gilt δ11B = 0.393 δ 13C - 30.73. Für BH3 leitet sich δ 11B zu -70.0 ppm ab.
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  • 89
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3146-3148 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 90
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    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3180-3185 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkaloids from Rhamnaceae, XXV Nummularine-A, -B and -C, Three New 13-Membered Ring Containing Peptide Alkaloids from Zizyphus NummulariaFrom the benzene extract of the root bark of Zizyphus nummularia, in addition to the known alkaloids Mucronin-D (1) and Amphibin-H (2), three further peptide alkaloids Nummularine-A, -B and -C have been isolated and their structures elucidated (3-5). All these alkaloids contain a thirteen-membered ring system formed by 5-hydroxy-2- methoxystyrylamine, trans-3-hydroxyproline and one other amine acid.
    Notes: Aus dem Benzolextrakt der Wurzelrinde von Zizyphus nummularia wurden neben den bekannten Alkaloiden Mucronin-D (1) und Amphibin-H (2) drei weitere Peptidalkaloide Nummularin-A, -B und -C isoliert und ihre Strukturen geklärt (3-5). Alle. genannten Alkaloide besitzen ein 13gliedriges Ringsystem, das aus 5-Hydroxy-2-methoxystyrylamin, trans-3-Hydroxyprolin und einer weiteren Aminosäure aufgebaut ist.
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  • 91
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Complexes of N-Containing Ligands, VI. Complexes Formation Reactions in the Systems Hexacarbonylchromium/2,3-Diazabicyclo[2.2.1]-hept-2-ene and Hexacarbonylchromium/Pyridazine2,3-Diazabicyclo[2.2.1]hept-2-ene (az, 1a) and pyridazine (pdz, 1b) may function as either monodentate two-electron ligands or bridging four-electron ligands in the reactions with carbonylchromium complexes (such as hexacarbonylchromium, pentacarbonyl(tetrahydrofuran)chromium, tetracarbonyl(norbornadiene)chromium (10), and tricarbonyl(cycloheptatriene)chromium (11). In addition to mononuclear complexes of the type Cr(CO)5L(L = az (2a), pdz (2b), cis-[Cr(CO) 4L2] (L = az (4a), pdz (4b), and fac-[Cr(CO)3L3] (L = pdz (7b)), binuclear coordination compounds of the composition (OC) 4 CrL2Cr(CO)4 (L = az (6a)) and (OC)3CrL3Cr(CO)3 (L = az (9a), pdz (9b)) can also be prepared. The new complexes have been characterised on the basis of their i. r. and 1H-n.m.r. spectra. The triplybridged complexes 9a, b are the thermally most stable and the kinetically least reactive derivatives in the systems Cr(CO)6/az and Cr(CO)6/pdz.
    Notes: Die cyclischen Ligandensysteme 2,3-Diazabicyclo[2.2.1]hept-2-en (az, 1a) und Pyridazin (pdz, 1b) können bei der Umsetzung mit Carbonylchrom-Komplexen (Hexacarbonylchrom, Pentacarbonyl(tetrahydrofuran)chrom, Tetracarbonyl(norbornadien)chrom (10) und Tris carbonyl(cycloheptatrien) chrom (11) sowohl als einzähnige Zweielektronenliganden als auch als brückenbildende Vierelektronenliganden auftreten. Neben einkernigen Komplexen des Typs Cr(CO)5L (L = az (2a), pdz (2b), cis-[Cr(CO)4L2] (L = az (4a), pdz (4b) und fac-[Cr(CO)3L3] (L = pdz (7b) lassen sich auch zweikernige Koordinationsverbindungen der Struktur (OC)4CrL2Cr(CO)4 (L = az (6a) und (OC)3CrL3Cr(CO)3 (L = az (9a), pdz (9b)) darstellen und anhand ihrer IR-und 1H-NMR-Spektren charakterisieren. Die dreifach verbrückten Komplexe 9a, b sind als die thermisch beständigsten und kinetisch stabilsten Derivate in den Systemen Cr(Co)6/az bzw. Cr(CO)6/pdz anzusehen.
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  • 92
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3260-3265 
    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)Nitrogen Compounds, 5A series of new mercury(I)-nitrogen donor ligand compounds (1-13), with positively charged nitrogen, has been prepared by the reaction of amines with mercury(I) nitrate in methanol/water or water. The nitrogen atoms are present as NH2-groups or as part of heterocyclic ring systems. Vibrational spectroscopy and X-ray results have been used to assign structural formations: group structures for compounds 1, 3 and 5-13 and chain structures for 2 and 4.
    Notes: Durch Umsetzung von Aminen mit Quecksilber(I)-nitrat, teils im System Methanol/Wasser und teils nur in wäßrigem Medium, konnte eine Reihe neuer Quecksilber(I)-Stickstoff-Verbindungen mit formal positiv geladenen Stickstoffatomen (1-13) erhalten werden. Das Stickstoffatom kann als NH2-Gruppe oder als Teil eines heterocyclischen Ringsystems vorliegen. Schwingungsspektroskopische und röntgenographische Untersuchungen weisen auf Gruppenstrukturen bei den Verbindungen 1, 3, 5-13 bzw. auf Kettenstrukturen bei den Verbindungen 2, 4 hin.
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  • 93
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3332-3336 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal and Molecular Structure of DihydrobotrydialThe structure of dihydrobotrydial (2), a derivative of the antibiotic botrydial (1), has been determined by single crystal X-ray diffraction using direct methods. The refinement led to an R-factor of 0.086.
    Notes: Die Struktur von Dihydrobotrydial (2), einem Derivat des Antibiotikums Botrydial (1), wurde durch Röntgenstrukturanalyse nach der Methode der symbolischen Addition bestimmt und bis zu einem R-Faktor von 0.086 verfeinert.
    Additional Material: 3 Ill.
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  • 94
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3340-3352 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Compounds, IV. Synthesis of Hexahydrochrysene DerivativesA one-step synthesis of the hexahydrochrysenes 3 by Diels-Alder reaction of the 1,2-dehydronaphthalenes 1 with the tetrahydrobenzo[b]furanes 2 is described. In some cases the benzo[c]-phenanthrenes 4 are isolated as by-products. The methylenation of the oxanorbornadienedouble bond of 3c leads to the cyclopropane 6.
    Notes: Eine Einstufendarstellung der Hexahydrochrysene 3 durch Diels-Alder-Reaktion der 1,2-Dehydronaphthaline 1 mit den Tetrahydrobenzo[b]furanen 2 wird beschrieben. In einigen Fällen erhält man die Benzo[c]phenanthrene 4 als Nebenprodukte. Durch Methylenierung der Oxanorbornadien-Doppelbindung von 3c gelangt man zum Cyclopropan 6.
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  • 95
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3395-3407 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbene Reactions, IV. Addition of Dimethoxycarbene to C—C Multiple BondsDimethoxycarbene (1) adds to diethyl fumarate or maleate to form diethyl 3,3-dimethoxycyclopropane-trans-1,2-dicarboxylate (6). Addition to styrene derivatives yields similarly 3,3-dimethoxycyclopropanes, whereas addition to acetylenedicarboxylate, phenylacetylene or diphenylketene led to 1:2-adducts of varying structure.
    Notes: Dimethoxycarben (1) addiert an Fumar- oder Maleinester unter Bildung von 3,3-Dimethoxy-cyclopropan-trans-1,2-dicarbonester (6). Bei der Addition an Styrol-Derivate entstehen ebenfalls 3,3-Dimethoxycyclopropane, während mit Acetylendicarbonester, Phenylacetylen oder Diphenylketen 1:2-Addukte unterschiedlicher Struktur resultieren.
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  • 96
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3426-3443 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Substitution, and Degradation of Phosphazo-Cyclotri(thiazene) Compounds1The silylated triorganyliminophosphoranes RR′2P=N—Si(CH3)3 1a-c (R,R′ = CH3, Ph) react with S4N4 with splitting off of N,N′-bis(trimethylsilyl)sulphur(IV) diimide and elementary sulphur to give the cyclic S-(phosphoranylidenamino)trithiatriazines 2a-c; the bis(iminophosphorane) (CH3)2P[NSi(CH3)3]- [CH2]3—P(CH3)2 [NSi(CH3)3] (5) reacts analogously to yield (CH3)2P(S3N4)- [CH2]3—P(CH3)2(S3N4) (6). 2a-c can be converted in to each other by replacing the respective phosphazo residue with a silylated phosphinimine1. The reaction order and equilibrium constant of this exchange reaction were determined. The cleavage of the cyclotri(thiazene) system 2b by the action of N-(trimethylsilyl)dimethylamine was studied and compared with the corresponding degradation of S4N4. The determination of the by-products of this reaction by means of GC and m. s. methods has furnished new information regarding the reaction course. E. s. r. spectroscopic studies of the thermal decomposition of 2a-c and 6 as well as of (CH3)2N—S—NSN—Si(CH3)3 proved the presence of SN2--anionic radicals in different concentrations.
    Notes: Die silylierten Triorganyliminophosphorane RR′2P=N—Si(CH3)3 1a-c (R, R′ = CH3, Ph) reagieren mit S4N4 unter Abspaltung von N,N′-Bis(trimethylsilyl)schwefel(IV)-diimid (3) und elementarem Schwefel zu den cyclischen S-(Phosphoranylidenamino)trithiatriazinen 2a-c, das Bis(iminophosphoran) (CH3)2P[NSi(CH3)3]-[CH2]3—P(CH3)2[NSi(CH3)3] (5) entsprechend zu (CH3)2P(S3N4)-[(CH2]3—P(CH3)2(S 3N4) (6). 2a-c sind durch Substitution des jeweiligen Phosphazo-Restes mit silyliertem Phosphinimin 1 ineinander überführbar. Die Reaktionsordnung und Gleichgewichtskonstante dieser Austauschreaktionen wird bestimmt. Die Spaltung des Cyclotri(thiazen)-Systems 2b durch N-(Trimethylsilyl)dimethylamin wird untersucht und mit dem entsprechenden S4N4-Abbau verglichen. Die GC-MS-Aufklärung der Nebenprodukte bringt neue Erkenntnisse über den Reaktionsverlauf. Durch ESR-spektroskopische Untersuchung der thermischen Zersetzung von 2a-c und 6 sowie von (CH3)2N—S—NSN—Si(CH3)3 können SN2--Anionoradikale unterschiedlich hoher Konzentration nachgewiesen werden.
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  • 97
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3454-3456 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 98
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3463-3475 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of Vinylogous Acyl Chlorides, XVI Synthesis and Reactivity of Chloro-substituted 2,2-Dialkyl-2H-pyransA new synthesis of chloro-substituted 2,2-dialkyl-2H-pyrans 8a-m is described by ring closure of the cis-pentadienols 6a-m with sodium in boiling petrol. The starting materials are prepared from the corresponding pentadienoic acid esters 5 or chlorides 7 by Grignard reagents. The pyrans are surprisingly stable on heating. Valence isomerization of 8a to the acyl chloride 15a occurs only at 230°C. This is an important fact considering the mechanism of 1,5-oxygen-transfer in cis-5,5-dichloro-2,4-pentadienone systems 1a. -Treatment of 8a with concentrated hydrochloric acid at 80°C causes ring contraction to the furan derivative 16a, which is converted by fuming nitric acid into 17a and proved in its structure by hydrogenation to 18. In the HNO3-degradation of the 6-phenyl-substituted pyran 8e benzoic acid was isolated besides 17a. On the basis of this result a possible reaction course is discussed.
    Notes: Die Behandlung der cis-Pentadienole 6a-m, die aus den Estern 5 oder Chloriden 7 der entsprechenden Pentadiensäuren mit Grignard-Reagentien dargestellt werden, mit Natrium in siedendem Benzin ermöglicht eine neue Synthese chlorsubstituierter 2,2-Dialkyl-2H-pyrane 8a-m. Diese sind thermisch überraschend stabil. Die Valenzisomerisierung des Pyrans 8a zum Säurechlorid 15a tritt erst bei 230°C ein und ist im Zusammenhang mit dem Mechanismus der 1,5-Pentadien-Sauerstoffverschiebung in cis-5,5-Dichlor-2,4-pentadienon-Systemen 1a bedeutsam. Konz. Salzsäure bei 80°C bewirkt eine Ringverengung des Pyrans 8a zum Furanderivat 16a. Durch rauchende Salpetersäure wird dieses weiter zu 17a abgebaut, das zum Strukturbeweis zu dem bekannten 18 hydriert wird. Beim HNO3-Abbau des 6-phenylsubstituierten Pyrans 8e wurde Benzoesäure neben 17a isoliert. Auf der Basis dieses Ergebnisses wird ein möglicher Reaktionsverlauf diskutiert.
    Additional Material: 2 Tab.
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  • 99
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    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3533-3547 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-(2-Nitrophenylsulfenyl)-α-amino Acid N-Carboxy Anhydrides (NPS-α-NCAs)α-Amino acid N-carboxy anhydrides (2,5-oxazolidinediones) 1 undergo substitution at the nitrogen atom rapidly, quantitatively and without racemization upon treatment with 2-nitrobenzenesulfenyl chloride and triethylamine below 0°C. Fourteen new NPS-α-NCAs (3a-c, e-h, k-q), some of them derived from trifunctional amino acids, were synthesized. The NPS-α-NCAs 3a-q, 6-8 can be stored without decomposition and they do not poly-merize. They undergo rapid racemization in the presence of small quantities of trialkylamines or pure pyridine. The racemization is investigated kinetically and the results are discussed. The NPS-α-NCAs 3a-q are not suitable for peptide synthesis in water-containing systems and give only low yields of NPS-dipeptides upon treatment with amino acid alkyl esters. Good yields of NPS-dipeptides 24 or free dipeptides are obtained by treatment of the NPS-α-NCAs with N-(trimethylsilyl)amino acid trimethylsilyl esters 22.
    Notes: Aminosäure-N-carbonsäure-anhydride (NCAs) (2,5-Oxazolidindione) 1 lassen sich mittels 2-Nitrobenzolsulfenylchlorid und Triäthylamin unterhalb 0°C schnell, quantitativ und racemisierungsfrei am Stickstoff sulfenylieren. Vierzehn neue NPS-NCAs (3a-c, e-h, k-q), zum Teil von trifunktionellen Aminosäuren, wurden synthetisiert. Die NPS-NCAs 3a-q, 6-8 sind lagerbeständig und polymerisieren nicht. Sie werden schon durch geringe Mengen an Trialkylaminen, aber auch durch reines Pyridin im Lauf von Stunden racemisiert. Die Racemisierung wurde kinetisch untersucht, und ihr Verlauf wird diskutiert. Die NPS-α-NCAs 3a-q eignen sich nicht zur Peptidsynthese in wäßriger Phase (Schotten-Baumann-Methode) und geben auch bei der Umsetzung mit Aminosäurealkylestern keine guten Resultate. Durch Umsetzung mit N-(Trimethylsily)aminosäureestern (22) lassen sich jedoch NPS-Dipeptide (24) in guten Ausbeuten gewinnen.
    Additional Material: 2 Ill.
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  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 107 (1974), S. 3589-3601 
    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, IV. The Reaction of Dimethylketene O, N-Acetals with Iso(thio)cyanatesDimethylketene O, N-acetals 1 react with arylisothiocyanates 2 to give the dipolar intermediates 3, which rearrange to the dimethylamalonic acid derivatives 4. In the reaction of 1 with sulfonyl isocyanates 8 the dipolar intermediate 9 can be isolated or identified spectroscopically; the dimethylmalonic acid derivatives 12 and 13 can be prepared by heating. A crossing experiment makes an intramolecular process probable for the rearrangement. The dipoles 9 can be protonated to the imidium salts 11. In the reaction of tosyl isothiocyanate (14) with 1 a rearrangement also occurs; the dipolar intermediate can only be isolated in the case of the sterically hindered acetal 1g.
    Notes: Dimethylketen-O,N-acetale 1 reagieren mit Arylisothiocyanaten 2 über die dipolare Zwischenstufe 3 unter Umlagerung zu den Dimethylmalonsäure-Derivaten 4. In der Reaktion von 1 mit Sulfonylisocyanaten 8 ist die dipolare Zwischenstufe 9 isolierbar oder spektroskopisch nachweisbar; durch Erhitzen können die Dimethylmalonsäure-Derivate 12 und 13 dargestellt werden. Ein Kreuzungsversuch macht für die Umalagerung einen intramolekularen Verlauf wahrscheinlich. Die Dipole 9 lassen sich zu den Imidium-Salzen 11 protonieren. Auch bei der Reaktion von Tosylisothiocyanat (14) mit 1 kann eine Umlagerung eintreten; die dipolare Zwischenstufe läßt sich nur bei der Reaktion mit dem sterisch gehinderten Acetal 1g isolieren.
    Additional Material: 1 Ill.
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