METHODS FOR CRYSTALLIZATION OF N-(1(S)-ETHOXYCARBONYL-3-PHENYLPROPYL)-L-ALANINE N-CARBOXYANHYDRIDE

摘要

A solution of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine N-carboxyanhydride in a good solvent therefor is added to an aliphatic hydrocarbon solvent to crystallize the N-carboxyanhydride while inhibiting the compound from separating out as an oily matter or scale. An aliphatic hydrocarbon solvent is gradually added to a solution of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine N-carboxyanhydride in a good solvent therefor at a temperature of 60 DEG C or lower over a 1/4 hour or longer to crystallize the N-carboxyanhydride.