摘要:

AbstractVarious reactions of 2‐oxo(or thioxo)‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylic acid derivatives (Biginelli‐compounds) were investigated. The site of methylation and acylation on 6‐methyl‐4‐phenyl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylic acid ethyl ester1aand its 2‐oxo derivative9awas studied. The synthesis of pyrimido[2,3‐b]thiazines and thiazolo[3,2‐a]pyrimidines was accomplished by condensation of1awith 1,3‐and 1,2‐dielectrophiles. A Dimroth‐like rearrangement yielding 6H‐1,3‐thiazines can be observed when1awas treated with dimethylformamide and phosphorus oxychloride. The formation of indeno[1,2‐d]pyrimidines can be achieved by intramolecular Friedl‐Crafts acylation of9aand13, respectively. Finally a route for the preparation of 4,6‐disubstituted‐pyrimidine‐5‐carbo

ISSN:0022-152X    

DOI:10.1002/jhet.5570260112

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractBenzocyclobutenols1were transposed by boron trifluoride etherate in the presence of triethylsilane into a new family of heterocycles2.

ISSN:0022-152X    

DOI:10.1002/jhet.5570260113

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractThe synthesis of 1,2,3,4‐tetrahydropyrazolo[4,3‐c][1]benzazepin‐1‐ones1and that of its 10‐methyl derivative2is reported. The preparation of the latter from 3‐(2‐aminobenzyl)3‐pyrazolin‐5‐one and triethyl ortho‐formate gave as the main product a derivative of the new tricyclic ring system, pyrazolo[1,5‐c][1,3]benzo‐diazepine. The structures of the new compounds synthesized were assigned b

ISSN:0022-152X    

DOI:10.1002/jhet.5570260114

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractThe formation of azo dyes by coupling the diazonium salts of aminophenyloxazolopyridines withN,N‐di‐ethylaniline was shown to be a suitable probe to check the stability of the oxazole ring in the course of their preparation. Depending on experimental conditions, “closed” and “opened” systems could be obtained

ISSN:0022-152X    

DOI:10.1002/jhet.5570260115

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractThe title compound1, has been shown to give a 1‐bromo derivative2when subjected to free‐radical bromination and a 1‐dimethylaminomethyl derivative3by reaction under standard Mannich conditions. Vilsmeier formylation, however, furnishes the 3‐substituted deri

ISSN:0022-152X    

DOI:10.1002/jhet.5570260116

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractImproved processes for the synthesis of bulk quantities of the anthrapyrazole clinical agents CI‐937, CI‐941, and piroxantrone hydrochloride are reported. Reported also are detailed analytical and spectroscopic data for these agents and intermediates of the synthetic sequen

ISSN:0022-152X    

DOI:10.1002/jhet.5570260117

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractA new synthesis of the recently reported 3‐(1H‐tetrazol‐5‐yl)‐4(3H)‐quinazolinone, sodium salt (1, MDL‐427), an experimental mediator release inhibitor, was developed from: (1) reaction of 5‐aminotetrazole3and triethyl orthoformate6to give ethylN‐(1H‐tetrazol‐5‐yl)formimidate8, (2) reaction of methyl anthranilate and imidate8to give amidine11, and (3) treatment of11with base to give1. Investigation of each of these steps independently led to a significantly more efficient, facile and higher‐yielding 1‐pot process. A brief examination of anthranilic acid13and its salts and derivatives14to17in this process found them to have dissimilar reactivities. The formation of amidine11as an isolable intermediate was unusual, as was its failure to cyclize under standard neutral or acidic conditions. The absolute requirement for base to effect cyclization of11

ISSN:0022-152X    

DOI:10.1002/jhet.5570260118

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractThe three isomeric pivaloylaminopyridines were lithiated in more than 80% yields. Aminopyridine derivatives were treated by 2.5‐3 equivalents of the complex BuLi‐TMEDA at −10° in diethyl ether. Reaction of the lithiated species with various electrophiles afforded a number ofortho‐substituted pivaloylaminopyridines in good yields. Secondary pyridine alcohols were oxidized to the corresponding aminopyridyl ketones. Pyridopyrimidines, benzonaphthyridines as well as an analogue of the natural antitumor alkaloid ellipticine has been synthesized showing the versatility of th

ISSN:0022-152X    

DOI:10.1002/jhet.5570260119

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractA one‐step synthesis of spiro[cycloalkane‐1,4′‐2H‐3′,1‐benzoxazin]‐2′‐ones and spiro[cycloalkane‐1,4′‐1H‐pyrido[2′,3′‐d][1,3′]oxazin]‐2′‐ones, obtained in good yield from the corresponding 1‐(o‐aminophenyl) and 1‐(2′‐amino‐3′‐pyridinyl)cycloalkanols is des

ISSN:0022-152X    

DOI:10.1002/jhet.5570260120

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY

摘要:

AbstractMono‐N‐methylation of 2‐(ortho‐R1‐anilino)‐4‐(p‐R2‐phenyl)‐3H‐1,5‐benzodiazepinesIVis achieved in moderate yield with sodium hydride in methyl iodide. Reaction of theN‐methyl derivativesIwith methoxyacetyl chloride gave the compoundsIIandIII. The structure of all products was confirmed by ir,1H

ISSN:0022-152X    

DOI:10.1002/jhet.5570260121

出版商:Wiley‐Blackwell    

年代:1989

数据来源: WILEY