A Convenient Method for the Preparation of Primary and Symmetrical N,N′-Disubstituted Thioureas
作者:R. Jason Herr、J. Louise Kuhler、Harold Meckler、Chester J. Opalka
DOI:10.1055/s-2000-7607
日期:——
A convenient process for the preparation of both primary thioureas 2 and symmetrical N,N′-disubstituted thioureas 6 based on the condensation of amine hydrohalides 5 with potassium thiocyanate has been developed. This approach tolerates sterically bulky primary amine substrates (both chiral and achiral), and the products can usually be isolated by a simple filtration of the reaction mixture. This method is an especially attractive alternative for the synthesis of thioureas when the corresponding isothiocyanates are unavailable, or difficult to prepare. It is also worth noting that a wide variety of amine hydrohalides, which are used in this procedure, are commercially available.
本研究开发了一种便捷的合成方法,通过胺的氢卤酸盐5与硫氰酸钾的缩合反应,可以制备初级硫脲2和对称的N,N'-二取代硫脲6。这种方法适用于空间位阻大的初级胺底物(包括手性和非手性),并且通常通过简单的反应混合物过滤即可分离产物。当相应的异硫氰酸酯无法获得或难以制备时,这种方法是合成硫脲的特别有吸引力的替代方案。值得注意的是,在该方法中使用的多种胺的氢卤酸盐在商业上是可获得的。