Preparation of imidazolones from n-cyano-n'-methylcarboxyguanidines. An unusual C-N bond formation in the hydrogenolysis of a benzyl ester in an attempted synthesis of an inhibitor of carboxypeptidase a
作者:Peter J. Garratt、Simon N. Thorn、Roger Wrigglesworth
DOI:10.1016/s0040-4020(01)80431-2
日期:1993.7
Hydrogenolysis of the benzyl ester 5 gave the imidazolone 6 rather than the desired acid 1, and the related benzyl ester 11 also hydrogenolysed to the imidazolone 12. Examination of the hydrolysis of simpler guanidine derivatives with trifluoroacetic acid suggested a unified mechanism for these processes which, in the case of the imidazolones, involves the intramolecular formation of a 7-membered ring
苄基酯5的氢解反应得到的是咪唑酮6而不是所需的酸1,相关的苄基酯11也被氢解为咪唑酮12。用三氟乙酸检查较简单的胍衍生物的水解表明,对于这些过程而言,存在一个统一的机理,在咪唑酮的情况下,涉及分子内形成7元环中间体的过程。水解反应提供了有用的,高产率的方法,用于将N-氰基亚胺基转化为其他官能团。