摘要:

AbstractThe relative rates of autoxidation at 140°C in the presence of 0.1% manganeous sterate were determined for 9 normal alkanes, 5 secondary alcohols, and 6 ketones. In the case of the n‐alkanes the oxidation rates increase linearly with the increasing chain length of the hydrocarbon. The oxidation rates of the secondary alcohols are about 3.3 times higher than those of the corresponding alkanes. The oxidation rates of the ketones are about 1.2 times higher than those of the corresponding alkan

ISSN:0021-8383    

DOI:10.1002/prac.19863280402

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractThe mole numbers of the starting paraffins, of the intermediate alcohols and ketones with the same chain lengths, of the lower alkan‐2‐ones, of the carboxylic acids, and of the esters were determined at different reaction times for the oxidations of n‐tridecane, n‐tetradecane, and n‐pentadecane with molecular oxygen at 140°C in the presence of 0.1% Mn‐stearate. In the stationary region of the oxidation about 1.2 moles of acids and 0.7 moles of esters are formed from 1 mole of paraffin consumed. The relative oxidation rates of alcohols and of ketones with reference to the starting paraffins were estimated from the mole numbers of the starting paraffins, the alcohols and the ketones at the maxima of the alcohols and the ketones. These values are higher than those determined by competitive oxidations, and this discrepancy is an indirect evidence of the formation of bifunctional intermediates from the starting paraffins. The relative rates of the formation of alcohols, ketones, and bifunctional products from normal paraffins we

ISSN:0021-8383    

DOI:10.1002/prac.19863280403

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

AbstractBy computer simulation of the dependencies of the mole numbers of the ketones and alcohols derived from the starting paraffin, of the acids and esters, and in some cases also of the lower alkan‐2‐ones on the paraffin conversion relative rate constants were determined on the basis of a plausible kinetic model of the paraffin oxidation. The data obtained show that about 67% of the oxidation proceeds via bifunctional primary products. With the aid of the relative rate constants determined a good simulation of the experimental mole number‐conversion curves is pos

ISSN:0021-8383    

DOI:10.1002/prac.19863280404

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

Structure Elucidation of a Product of Intramolecular Diels‐Alder‐Reaction: Configurational and Conformational Analysis of 5‐Methyl‐2‐phenyl‐1H,2,3,3a,4,5,7a‐hexahydroisoindol‐1‐oneN‐Allyl‐N‐phenylsorbamide1cyclizes at 160°C to give 5‐methyl‐2‐phenyl‐1H,2,3,3a,4,5,7a‐hexahydroisoindol‐1‐one2. As a result of this intramolecular [4 + 2] cycloaddition four stereoisomeres2a–2dcan exist. The1H and13C n.m.r. data are given. The1H n.m.r. studies demonstrate that the product of Diels‐Alder cyclisation is the result of cis‐fusion of the two rings. The nuclear Overhauser effect data provide further evidence for2ain which the carbonyl group and methyl one are trans‐arranged. The

ISSN:0021-8383    

DOI:10.1002/prac.19863280405

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

Synthesis and Spectral Characterization of Blue Azo Dyes of the Benzene Series53 Donor‐acceptor substituted azo dyes of the benzene series were prepared by diazonium‐coupling reactions (1 a–s) or halogen‐cyanide exchange (→2 a–x, 3 a–j). Described are the preparation of the amines4 a–mand the coupling compounds5 a–tand the procedure of diazotizing and coupling.The colouristic and spectroscopic data show that compounds of the general formula1are excellent brilliant blue azo dyes useful for dyeing p

ISSN:0021-8383    

DOI:10.1002/prac.19863280406

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

ISSN:0021-8383    

DOI:10.1002/prac.19863280407

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

About the Reactions of Benzimidazole‐2‐carbohydrazide with Electrophilic CompoundsBenzimidazole‐2‐carbohydrazide (1) reacts with aldehydes and ketones to form N‐alkylidene‐benzimidazole‐2‐carbohydrazides(2a–j). With carbon disulfide, diphenyl carbonate and cyanates, ring closure takes place to afford 1,2,4‐triazines and 1,3,4‐oxadiazoles. Attempts to synthezise 2‐isocyanato‐benzimidazole failed.1H‐n.m.r. and13C‐n.m.r. spectroscopic da

ISSN:0021-8383    

DOI:10.1002/prac.19863280408

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

Abstract6‐Arylpyridazin‐3(2H)‐thiones exist mainly, if not entirely, in the thione form (1). This was shown by spectroscopic studies on some of these compounds and their substitution products either on the nitrogen or on the sulphur [in the mercaptopyridazine form (2)]. However, the reacting tautomer of these compounds was found to be dependent upon the basicity of the reaction medium. Selected 6‐arylpyridazin‐3(2H)‐thione derivatives react with formaldehyde and sec‐amines to give N‐2‐aminomethyl derivatives (8) [thione form (1)]. On the other hand oxidation and alkylation reactions gave disulphides (10) and S‐alkyl derivatives (7)

ISSN:0021-8383    

DOI:10.1002/prac.19863280409

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

α‐Amino Ketones – A Contribution to the Synthesis of Optically Active Derivatives of Amino Acids and PeptidesThe synthesis of N‐Z‐protected methyl ketonesDie Nomenklatur der Ketonderivate von Aminosäuren und Peptiden entspricht den IUPACIUB Nomenclature Recommendations 1983, Eur. J. Biochem.138(1984) 9. Um die Beziehung zu den Aminosäuren herzustellen, wird für Aminoaceton die Bezeichnung Glycylmethan GlyCH3benutzt.Weitere verwendete Abkürzungen: Z‐ = Benzyloxycarbonyl‐, E = Ether, PE = Petrolether, EE = Essigsäureethylester, CABE = Chlorameisensäure‐i‐butylester, TEA = Triethylamin, DMAP = 4‐Dimethyl‐aminopyridin, HMDS = Hexamethyldisiloxan, TMS = Tetramethylsilan, TRH = Thyreotropin Releasing Hormon, MSH‐RIF (MIF) = MSH‐Release‐Inhibiting‐Factor (MSH = Melanocyten stimulierendes Hormon).from amino acids via the chloromethyl ketones and dehalogenation of the latter with zinc in glacial acetic acid is described. Deprotection of the methyl ketones results in the formation of hydrohalogenides of the α‐aminoalkyl methyl ketones further converted to N‐acylated peptide ketones as analogs of peptide hormones or as competitively acting substrate analogs of proteolytic enzymes. Aminoacetone is conveniently prepared as well as methyl‐pyrr

ISSN:0021-8383    

DOI:10.1002/prac.19863280410

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY

摘要:

Electrochemical Carboxylation of Substituted Vinyl Ketonesα‐Chlor‐β‐acyl‐vinylsulphides (1a–f) and keten‐S, N‐acetales (3a,b) are reduced in the presence of CO2at the cathode to yield the corresponding acids (4a–fresp. 5). Whereas the carboxylation of1proceeds via elimination‐addition mechanism, the reduction of3is similar to the keten‐S, S‐acetales described earlier an EC (addition) EC

ISSN:0021-8383    

DOI:10.1002/prac.19863280411

出版商:WILEY‐VCH Verlag GmbH    

年代:1986

数据来源: WILEY