摘要:

AbstractThe proportion of difunctional and monofunctional products with the original carbon skeleton was determined in the oxidates of n‐decane, n‐tridecane, n‐pentadecane, and n‐octadecane to about 0.32. This proportion does not significantly depend on the conversion of the starting paraffin. As well as mono‐ and difunctional products with the original carbon skeleton already at very low conversions of n‐tridecane, about 45% of lower oxygen‐containing compounds, for example aldehydes, alkan‐2‐ones, carboxylic acids and γ‐lactones, are also obtained. Obviously, a part of the difunctional primary products reacts very fast with scission of the carbon chain, forming lower oxygen

ISSN:0021-8383    

DOI:10.1002/prac.19873290402

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe reaction of 3‐amino‐2,4‐diethoxycarbonylcrotononitrile with cinnamonitrile derivatives afforded the pyrimidines5a‐‐dand not the pyridines4as expected from literature. Similarly pyrimidines5e‐‐hwere produced when 3‐amino‐2,4‐dicyanocrotononitrile was treated with the same reagent. The structure was established based on MS and high resolution1H

ISSN:0021-8383    

DOI:10.1002/prac.19873290403

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe synthesis of 5H‐thiopyrano[4,3‐b]pyridines, 8H‐thiopyrano[3,4‐b]pyridines, 1H‐thiopyrano[3,4‐c]pyridines and 1H‐thiopyrano[4,3‐c]pyridines from methyl pyridine esters5–8and nitriles17–20by simple photobromination, followed by reaction of the intermediate bromomethyl derivative with methyl thioglycolate and subsequent base induced cyclisation of the

ISSN:0021-8383    

DOI:10.1002/prac.19873290404

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractSodium hydride prompted reactions of diethyl anilinodiacetate1with acetophenone, p‐nitroacetophenone, p‐fluoroacetophenone and acetylthiophene result in the formation of tetraketones3a–d. Evidence is presented to support the formation of3a–d, via a sequence of reactions involving condensation with hydrazine, their acetyl derivatives, and cyclization with polyphosphoric acid. The structures of the hitherto unknown ring systems have been confirmed by i.r., p.m.r. and mass spectr

ISSN:0021-8383    

DOI:10.1002/prac.19873290405

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractAryltropylium salts exhibit an unusually effective self quenching of fluorescence in dependence on their concentration in dichlòromethane. The quenching process is investigated by static and time resolved fluorescence measurements. The observed biexponential fluorescence decay is interpreted by the emissions of ion pairs and free cations. The rate constant of fluorescence quenching by formation ion pair is two orders of magnitude greater than the diffusion constant

ISSN:0021-8383    

DOI:10.1002/prac.19873290406

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe direct condensation reaction of prop‐2‐enal or but‐2‐enal with mixture of n‐aliphatic alcohol and ethylene glycol, in the presence of p‐toluenesulphonic acid as catalyst, leads to a complex mixture of saturated, unsaturated, cyclic and linear acetals, moreover, 2‐(2‐alkoxy‐alkyl)‐1,3‐dioxolanes are the main reaction products. The detailed investigations for n‐butanol showed that unsaturated cyclic acetals: 2‐vinyl‐1,2‐dioxolane1aor 2‐(1‐propenyl)‐1,3‐dioxolane1b, as well as unsaturated linear acetals: 1,1‐dibutoxy‐prop‐2‐en2aor 1,1‐dibutoxy‐but‐2‐en2bare intermediate reaction products. Additionally, it was found in final products presence of eight by‐products: 5‐butoxy‐4aor 5‐butoxy‐7‐methyl‐1,4‐dioxepane4b, 1,1,3‐tributoxypropane5aor 1,1,3‐tributoxybutane5b, 2‐[2‐(2‐hydroxyethoxy)ethyl]‐6aor 2‐[2‐(2‐hydroxyethoxy)propyl]‐1,3‐dioxolane6b, 5‐(2‐hydroxyethoxy)‐7‐methyl‐1,4‐dioxepane7b, 1,3‐dibutoxy‐1‐(2‐hydroxyethoxy)‐propane8aor 1,3‐dibutoxy‐1‐(2‐hydroxyethoxy)‐butane8b, 1,1‐dibutoxy‐3‐(2‐hydroxyethoxy)‐propane9aor 1,1‐dibutoxy‐3‐(2‐hydroxyethoxy)‐butane9b, 3‐butoxy‐1,1‐bis‐(2‐hydroxyethoxy)‐propane10aor 3

ISSN:0021-8383    

DOI:10.1002/prac.19873290407

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractThe arithmetic means of wave numbers of symmetric and antisymmetric CO stretching vibrations measured in tetrachloro‐ and trichloromethane of 31 substituted maleinimides were correlated with Taft inductive σ*substituent constants. The series of N‐phenyl and N‐(4‐methylphenyl) derivatives exhibit normal i.e. positive values of slope of vs σ*correlations. In series of substituted N‐methylmaleinimides (and probably also in maleinimides) the negative values of slope of vs σ*correlations indicate a reversed substituent effect on the CO stretching vibration. The mechanism of transmission of substituent effects in maleinimidee system is discussed considering the results of above mentio

ISSN:0021-8383    

DOI:10.1002/prac.19873290408

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

Abstract[4,4′‐Bipyridine]‐3,3′‐diamine (1) reacts with HNO2in H2SO4to form 2,7,9,10‐tetraazaphenanthrene (2) and 9H‐pyrrolo[2,3‐c:5,4‐c′]dipyridine (3) instead of expected bipyridinediol4or furodipyridine5. On the other hand, diazotization of1in hydrohalogenic acids leads to novel 3‐halogeno‐2,7,9,10‐tetraazaphenanthrenes10or11and this reaction represents a new type of regioselective nucleophilic substitution of hydrogen atom in heteroaromatic species. The proposed pathway of reactions was supported by an experiment with the hypothetic intermediate, i.e. 2,7,9,10‐tetraazaphenanthrene‐9‐imine (8), which wa

ISSN:0021-8383    

DOI:10.1002/prac.19873290409

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

Reaction Behaviour of 2‐Ethoxycarbonyl‐3‐hydroxy‐N‐phenyl‐maleimideThe vinylogous acid1gives with amines under various conditions the ammonium salts2a–f. 2‐Ethoxycarbonyl‐3‐chloro‐N‐phenyl‐maleinimide5obtained by the chlorination of1leads to N‐substituted 2‐ethoxycarbonyl‐maleimides6a–dand condensed heterocycles7a,b.The reaction of1with 2‐methylindol forms8a,bor gives with methyleneactive compounds 2‐ethoxycarb

ISSN:0021-8383    

DOI:10.1002/prac.19873290410

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

Synthesis and Reaction Behaviour of 2‐Arylhydrazono‐N‐phenyl‐succinimides2‐Arylhydrazono‐N‐phenyl‐succinimides4a–fare prepared by the heating of 2‐ethoxycarbonyl‐3‐hydroxy‐N‐phenyl‐maleimid1with arylhydrazines or ammonium salts2a–cin acetic acid. The Knoevenagel condensation of the methyleneactive compound4awith aldehydes in the presence of pyridine forms the corresponding Z‐isomers5a–e.The succinimides4a–care deprotonated to the anions6a–c, which with heterocumulenes give the new keten‐S,S‐ and keten‐S,N‐acetals7a–c,8a–cand (Z/E)‐9a,b. The intramolecular cyclization of7band (Z/E)‐9bleads to 1,5‐disubstituted pyrazol‐3,4‐dicarboxylic imides10a,b. Further derivatives of these heterocyclic ser

ISSN:0021-8383    

DOI:10.1002/prac.19873290411

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY