Synthesis and tautomerism of ethyl 2-(2-benzothiazolyl)-2-(6-purinyl)acetate and related compounds
作者:L. H. Klemm、Susan Johnstone、Long K. Tran
DOI:10.1002/jhet.5570260602
日期:——
Reaction of 6-chloro-9H-(2-tetrahydropyranyl)purine (2d) with the sodium salt of ethyl benzothiazole-2-ace-tate (1) in dimethylformamide effects condensation of the two compounds (with loss of sodium chloride) to give the corresponding ethyl diarylacetate 4 (35%), present largely as an enol chelate tautomer. Isolated as a by-product is 6-(2-aminophenyl-1-thio)-9H-(2-tetrahydropyranyl)-purine (4%),
6-氯9 H-(2-四氢吡喃基)嘌呤(2d)与苯并噻唑-2-乙酸乙酯(1)的钠盐在二甲基甲酰胺中的反应导致两种化合物的缩合(氯化钠损失)得到相应的二芳基乙酸乙酯四(35%),主要以烯醇螯合互变异构体形式存在。分离作为副产物是6-(2-氨基苯基-1-硫代)-9 ħ - (2-四氢吡喃基) -嘌呤(4%),形成经由噻唑环的开口。通过用p处理将四氢吡喃基保护基团从4个基团上除去。-甲苯磺酸在乙醇水溶液中生成苯并噻唑-2-(6-嘌呤基)乙酸乙酯(80%),主要作为两种烯醇螯合异构体存在。给出了各种产品的光谱数据。在第一反应中尝试使用6-氯-9-乙酰基-9 H-嘌呤代替2d会产生1的乙酰化而不是缩合。