摘要:

AbstractThe 4‐bromo‐3‐phenylpyrazol‐5‐ylhydrazonyl chlorides (Ia,b) and 1,2,4‐triazol‐5‐ylhydrazonyl chlorides (IIa,b) were preparedviacoupling of diazotized 4‐bromo‐3‐phenyl‐5‐aminopyrazole (III) and 5‐amino‐1,2,4‐triazole (IV) with α‐chloro derivatives of acetylacetone and of ethyl aceto‐acetate. Compounds Ia and IIa,b were utilised for the synthesis of

ISSN:0022-152X    

DOI:10.1002/jhet.5570170201

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractThe CD spectra of a series ofN‐5(6)benzofuroxanoyl‐L‐α‐amino acids and esters reveal, in ethanol and acetonitrile, cotton effect (CE) bands around 365, 320, 265 and 223 nm. It was found that the signs of the CE maxima, located at longest and shortest wavelengths, were both positive for the L ‐aliphaticseries, whereas these bands display sign inversion in the CD spectra of the L ‐aromaticcounterparts. This chiroptical behaviour might be attributed to conformational differences. Nmr spectral data give support to this assumption. Mass spectral fragmentations of these compounds a

ISSN:0022-152X    

DOI:10.1002/jhet.5570170202

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractThe synthesis ofcis‐ andtrans‐2,4‐diphenylazetidines as well as that of theirN‐nitroso derivatives is described. The “abnormal” reduction of theN‐nitrosamines gives acis‐transmixture of the expected 1,2‐diphenylcyclopropanes. However, no stereochemical correlations could be made owing to the base‐induced isomerization of the startingN‐nitrosamines during the c

ISSN:0022-152X    

DOI:10.1002/jhet.5570170203

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

Abstract7‐Substituted 4‐hydroxycoumarins(2a‐e)and 4‐hydroxy‐2‐quinolones(2f‐i)have been synthesized from the appropriate phenols or anilines and were converted to the enamines3using triethoxymethane and aniline. Condensation of3with nitriles4a‐hgave substituted 2H,5H‐pyrano[3,2‐c]benzopyran‐2,5‐diones(5a‐r)or 2H,5H‐pyrano[3,2‐c]quinoline‐2,5‐diones(5s‐x), which exhibit both spontaneous and stimulated fluorescence with maxima between 418 and 549 nm. The marked influence of an electron withdrawing 3‐substituent in5is demonstrated by the fluorescence spectra of7a,b(synthesized from2d,eand ethyl 3‐oxobutyrate), whose maxima are sharply shifted to

ISSN:0022-152X    

DOI:10.1002/jhet.5570170204

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractReactions of ethyl 3‐ethoxymethylene‐2,4‐dioxovalerate(1)with phenyl‐ and methylhydrazines are described. While the reaction of1with phenylhydrazine gave a mixture of ethyl 4‐acetyl‐1‐phenylpyrazole‐5‐carboxylate(4)and ethyl 5‐methyl‐1‐phenylpyrazole‐4‐glyoxylate(5), 1reacted with methylhydrazine to give ethyl 4‐acetyl‐1‐methylpyrazole‐3

ISSN:0022-152X    

DOI:10.1002/jhet.5570170205

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractDans cet article les auteurs décrivent la synthèse et les propriétés physico‐chimiques de nouvelles pyrido[2,3‐d]pyrimidinediones‐2,4 mono ou disu

ISSN:0022-152X    

DOI:10.1002/jhet.5570170206

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

Abstract1,3,3‐Trimethyl‐2‐(3,4,5‐trimethoxyphenyl)‐4‐methylenepiperidine (XI) is prepared in an unambiguous way which involves the Refortmatsky reaction followed by ethanolysis on theN‐(3,4,5‐trimethoxybenzylidene)methylamine, later treatment of the resulting aminoester with ethyl acrylate, ring closure by Dieckmann reaction with decarbalkoxylation and, finally, a Wittig reaction on the piperidone obtained. The resulting methylenepiperidine XI differs in its physical and spectroscopic data from the methylene derivative IIIa obtained by the Stevens rearrangement of the 1,3,4‐trimethyl‐1‐(3,4,5‐trimethoxybenzyl)‐1,2,5,6‐tetrahydropyridinium chloride, whose

ISSN:0022-152X    

DOI:10.1002/jhet.5570170207

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractOn décrit une nouvelle synthèse de pyrido[4,3‐b]quinoléines diversement substituées sur leur sommet 1 qui comporte seulement trois étapes. Ainsi, les hydroxy‐2 arylamino‐4 pyridines sont transformées dans les conditions de la réaction de Vilsmeir‐Haack en donnant directement les oxo‐1 dihydro‐1,2 pyrido[4,3‐b]quinoléines; la chloration de ces dernières engendre ensuite les chloro‐1 pyrido[4,3‐b]quinoléines qui sont aisément substi

ISSN:0022-152X    

DOI:10.1002/jhet.5570170208

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractA new procedure for the cyclization of 2‐indolecarbohydrazones(5)to 1,2,3,4‐tetrahydro‐4‐oxo‐5H‐pyridazino[4,5‐b]indoles(6)and for the cyclization of 3‐indolecarbohydrazones(7)to 1‐oxo‐1,2,3,4‐tetrahydro‐5H‐pyridazino[4,5‐b]indoles(8and9)is described. The hydrazones(5or7)were treated with an acyl halide (acetyl or benzoyl chlorides) and triethylamine in ethyl acetate of chloroform as solvents to give the compounds6(20–70%) from the compounds5, and the compounds8(20–60%) from the compounds7. Through refluxing with ethanol‐hydrochloric acid the compounds8a‐8fselectively separate the acetyl group on N5to give the respective compounds,9a‐9f.The ir and1H‐nmr spectra of all the compounds5, 6, 7, 8and9and the uv, mass and13C‐nmr spectra of

ISSN:0022-152X    

DOI:10.1002/jhet.5570170209

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractDeux nouvelles synthèses de la thiéno[2,3‐b]pyrazine sont décrites avec la méthyl pyrazine comme produit de départ. L'une des méthodes consiste en une voie originale d'obtention d'un cycle thiophénique dans un système à noyaux

ISSN:0022-152X    

DOI:10.1002/jhet.5570170210

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY