Benzyloxycarbonylamino acid 2,6-Dichloro-4-nitrophenyl esters and the reaction of 2,6-Dichloro-4-nitrophenol with N,N'-Dicyclohexylcarbodiimide

Abstract

2,6-Dichloro-4-nitrophenyl esters of several benzyloxycarbonylarnino acids have been prepared from 2,6-dichloro-4-nitrophenol by the N,N'-dicyclohexyl-carbodiimide method. The course of this reaction differed from the analogous preparation of related active esters in that the phenol and the carbodiimide react to form a 1 : 1 molecular complex of the phenol and N,N'-dicyclohexyl-0-2,6-dichloro-4-nitrophenylisourea. This complex is readily isolated, and behaves as an active esterifying agent.