Preparation of New Nitrogen-Bridged Heterocycles. 48. Syntheses and Reactions of Ethyl 3-[2-(Methylthio)indolizin-3-yl]acrylate Derivatives.
作者:Akikazu KAKEHI、Suketaka ITO、Hoh SA
DOI:10.1248/cpb.47.1607
日期:——
Title compounds were prepared in 20-72% yields from the S-aklylation of pyridinium 1- [3-ethoxycarbonyl-1-[(methylthio)thiocarbonyl]]allylides with some alkyl halides, followed by the treatment of the resulting pyridinium salts with a base and then a dehydrogenating agent. In part of these reactions novel heterocycles, ethyl 1-cyano-3-(methylthio)thieno[3, 4-b]indolizine-9-carboxylates, were also formed. The oxidation of the title compounds with m-chloroperbenzoic acid gave the corresponding sulfoxides in moderate to good yields, which smoothly underwent Pummerer reactions on treatment with acetic anhydride. The bromination of the 3-vinyl group in the title compounds, followed by treatment of the resulting dibromo adducts with a base afforded ethyl 2-bromo-3-[2-(methylthio)indolizin-3-yl]acrylates, 3-[1-cyano-2-(methylthio)indolizin-3-yl]propiolates, and ethyl thieno[2, 3-b]indolizine-2-carboxylate depending upon the substrate used.
1- [3-乙氧羰基-1-[(甲硫基)硫代羰基]]烯丙基吡啶与一些烷基卤化物发生 S-烷基化反应,然后用碱和脱氢剂处理生成的吡啶鎓盐,制备了标题化合物,收率为 20-72%。在部分反应中还生成了新型杂环,即 1-氰基-3-(甲硫基)噻吩并[3, 4-b]吲嗪-9-羧酸乙酯。标题化合物与间氯过苯甲酸的氧化反应产生了相应的硫氧化物,收率从中等到良好。将标题化合物中的 3-乙烯基溴化,然后用碱处理生成的二溴加合物,可得到 2-溴-3-[2-(甲硫基)吲哚嗪-3-基]丙烯酸乙酯、3-[1-氰基-2-(甲硫基)吲哚嗪-3-基]丙二醇酯和噻吩并[2, 3-b]吲哚嗪-2-甲酸乙酯,具体取决于所用的底物。