摘要:

AbstractThe preparation of some functionalized quinoxaline 1,4‐dioxides is described from the reaction of benzofurazan oxide with 2‐acetylbutyrolactone, ethyl acetopyruvate, and acetylacetaldehyde dimethylace

ISSN:0022-152X    

DOI:10.1002/jhet.5570180401

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractThe title compound, a potential anthelmintic agent, was prepared in seven steps from 5‐hydroxy‐2‐picoline. The intermediate 5‐(N,‐phenylbenzamido)‐2‐picoline was prepared by a facile Chapman rearrangement of the corresponding benzimidoyl ester. Oxidation and Curtius rearrangement of the substituted picoline gave 5‐(N‐phenylbenzamido)‐2‐aminopyridine which underwent ring closure and debenzoylation to furnish methyl 6‐phenylaminoimidazo[1,2‐α]pyridine‐2‐carbamate. Fries rearrangement of the penultimateN‐benzoyl derivative gave a 6‐(p‐benzoylphenylamino)imidazo[1,2‐α]pyridine derivative, whose structure was confirmed by cmr study. The title compound l

ISSN:0022-152X    

DOI:10.1002/jhet.5570180402

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractThe first reported synthesis of 3‐formyltetronic acid and its conversion to enamine derivatives is described. 3‐Dimethylaminomethylene‐2,4‐dioxotetrahydrofuran derivatives were also prepared by treatment of tetronic acids with dimethylformamide diethyl acetal. Nmr spectral studies are i

ISSN:0022-152X    

DOI:10.1002/jhet.5570180403

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractA method for the regiospecific synthesis of 3‐substituted 2‐aroylpyrroles is described. These pyrroles, which are structurally related to the naturally occurring antibiotic pyoluteorin, are prepared by a Friedel‐Crafts aroylation of 4‐substituted pyrrole‐3‐carboxylic acid esters with 2,6‐dimethoxybenzoyl chloride. The carboalkoxy group is then removed by hydrolysis and decarboxylation to produce isomerically pure 3‐substituted‐2‐(2′,6′‐dimethoxybenzoyl)pyrroles (5and13). Conversion of these pyrroles into pyoluteorin‐like compounds led to some unexpected products which arise from facile cleavage of the dihydroxybenzoyl portion of the mo

ISSN:0022-152X    

DOI:10.1002/jhet.5570180404

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractSynthesis of 2‐amino‐6‐hydroxymethyl‐4‐(3H)pyrido[3,2‐d]pyrimidinone (5) from 2‐amino‐6‐methyl‐4‐(3H)‐pyrido[3,2‐d]pyrimidinone (2) was accomplished by selenium dioxide oxidation of2to the aldehyde4followed by sodium borohydride reduction. Compound2was available in four steps from 5‐aminouracil or in two steps from 5‐nitroisocytosine (3a). Catalytic reduction of4or5gave a mixture of 2‐amino‐6‐methyl‐5,6,7,8‐tetrahydro‐4‐(3H)pyrido[3,2‐d]pyrimidinone (6a) and the 6‐hydroxymethyl compound6b. These compounds showed only weak inhibitory activity in the coupled reactions catalyzed by 7,8‐dihydro‐6‐hydroxymethylpterin pyrophosphokinase and 7,8‐dihydropteroate synthetase fromE. C

ISSN:0022-152X    

DOI:10.1002/jhet.5570180405

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractAcyltriphenylphosphoniummethylides react with diazoazoles in a [2 + 7]‐ or [2 + 11]‐cycloaddition reaction followed by elimination of triphenylphosphane oxide to yield azolo[5,1‐c][1,2,4]tria

ISSN:0022-152X    

DOI:10.1002/jhet.5570180406

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractThe synthesis is described of a number ofN‐substituted 2‐amino‐5,8‐dimethoxychromones (1) by replacement of the sulphoxide group in 2‐ethylsulphinyl‐5,8‐dimethoxychromone (5a) with the appropriate amine. Analogous substitution of 2‐ethylsulphonyl‐5,8‐dimethoxychromone (5b) is also possible but limited by the instability of the sulphone. Replacement reactions of5ainvolving oxygen, sulphur, and phosphorus nucleophiles

ISSN:0022-152X    

DOI:10.1002/jhet.5570180407

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractThe first synthesis of a tetrazinophane, from 2‐nitrosocyclodecane‐1,3‐dione, is rep

ISSN:0022-152X    

DOI:10.1002/jhet.5570180408

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractConditions for the mono‐ and di(thiomethylation) ofN‐methyl‐3‐ethyl‐3‐phenylpiperidine‐2,6‐dione and the monothiomethylation ofN‐methyl‐3‐(4‐aminophenyl)‐3‐ethylpiperidine‐2,6‐dione, potential inhibitors of estrogen synthetase, are described and contrasted with a closely related lactam,N‐methylpiperidone. The influence of solvent, base and electrophile on

ISSN:0022-152X    

DOI:10.1002/jhet.5570180409

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY

摘要:

AbstractThe synthesis of the novel enamide isoquinoline alkaloid polycarpine, (Z)‐1‐(2′‐hydroxy‐3′,4′‐dimethoxy‐benzylidene)‐3,4‐dihydro‐6,7‐dimethoxy‐2‐(1H)isoquinolinecarboxaldehyde, proceeding from commercially available 2′,3′,4′‐trimethoxyacetophenone in seven steps is described. TheO‐methyl and

ISSN:0022-152X    

DOI:10.1002/jhet.5570180410

出版商:Wiley‐Blackwell    

年代:1981

数据来源: WILEY