Reactions of 5-mercaptoazoles and pyridine-2-thiones with acetylenic esters. Selectivity of the formation of novel fused thiazin-4-ones and thiazolidin-4-ones
作者:Vasiliy A. Bakulev、Vera S. Berseneva、Natalia P. Belskaia、Yury Yu. Morzherin、Andreiy Zaitsev、Wim Dehaen、Ingrid Luyten、Suzanne Toppet
DOI:10.1039/b207854f
日期:2003.12.19
A systematic study of the reactions of dimethyl acetylenedicarboxylate (DMAD) and methyl propynoate with 5-mercaptoazoles and pyridine-2-thiones has been carried out and as a result, a number of novel imidazo[1,5-b]thiazin-4-ones 6a,b, pyrazolo[1,5-b] thiazin-4-ones 15a–f, imidazo[1,5-b]thiazol-4-ones 7a,b and thiazolo[3,2-a]pyridines 21a–c have been prepared. The influence of the size of the ring of the starting “cyclic” thioamides on the size of the fused ring in the reaction products has been established. The preferred formation of a six-membered thiazine ring took place in the reactions of 5-mercaptoazoles. In contrast, the five membered thiazolidine ring is formed in reactions of pyridine-2-thiones. In both cases the product is a five-membered ring fused to a six-membered heterocycle.
对乙酰二羧酸二甲酯(DMAD)和丙炔酸甲酯与 5-巯基唑和吡啶-2-硫酮的反应进行了系统研究,结果发现:6a,b、吡唑并[1,5-b]噻嗪-4-酮 15a-f、咪唑并[1,5-b]噻唑-4-酮 7a,b 和噻唑并[3,2-a]吡啶 21a-c。已经确定了起始 "环状 "硫代酰胺环的大小对反应产物中融合环大小的影响。在 5-巯基偶氮唑的反应中,优先形成的是六元噻嗪环。相反,五元噻唑烷环是在吡啶-2-硫酮的反应中形成的。在这两种情况下,产物都是一个与六元杂环融合的五元环。