unexpected thiazole 1B formation when 2,6‐dichlorobenzothioamide 1 and ethyl bromopyruvate were reacted under basic conditions at elevated temperatures in ethanol. Thiazole 1B, regio‐isomeric to that expected under conventional Hantzsch conditions, was extensively characterized and later confirmed by single crystal X‐ray structure. We carried out this transformation with several substituted benzothioamides and
我们观察到,在碱性条件下,在
乙醇中升高的温度下,当2,6-二
氯苯并
硫代酰胺1与
溴丙酮酸乙酯反应时,
噻唑1B会意外地形成。
噻唑1B与常规Hantzsch条件下预期的区域异构体具有广泛的特征,后来通过单晶X射线结构得到证实。我们用几种取代的苯并
硫代酰胺进行了这种转化,发现意外的
噻唑区域异构体的形成高度依赖于苯环上邻位取代基的空间位阻和电子特性。提出了一种机制来解释这种新颖的转变。