Thiazol-4-one derivatives from the reaction of monosubstituted thioureas with maleimides: structures and factors determining the selectivity and tautomeric equilibrium in solution
作者:Alena S Pankova、Pavel R Golubev、Alexander F Khlebnikov、Alexander Yu Ivanov、Mikhail A Kuznetsov
DOI:10.3762/bjoc.12.251
日期:——
2-(Alkyl(aryl)amino)thiazol-4(5H)-ones can regioselectively be prepared from monoalkyl(aryl)thioureas and maleimides. In solution, the former heterocycles exist in a tautomeric equilibrium with 2-(alkyl(aryl)imino)thiazolidin-4-ones and the substituent on the exocyclic nitrogen atom governs the ratio of these tautomers. Isomers with the alkyl group in the endocyclic position can be obtained from N
2-(烷基(芳基)氨基)噻唑-4(5H)-可以由单烷基(芳基)硫脲和马来酰亚胺区域选择性地制备。在溶液中,前者的杂环与2-(烷基(芳基)亚氨基)噻唑烷酮-4-酮处于互变异构平衡状态,环外氮原子上的取代基控制这些互变异构体的比例。可以从N-甲基(乙基)硫脲获得在内环位置具有烷基的异构体。2D NMR光谱和DFT计算合理化了实验结果。