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

摘要

A crystallization is carried out by adding a solution of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine N-carboxylic anhydride in a good solvent to an aliphatic hydrocarbon solvent while inhibiting the oil formation and scaling of said N-carboxylic anhydride.

Further, a crystallization is carried out by adding an aliphatic hydrocarbon solvent sequentially to a solution of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine N-carboxylic anhydride in a good solvent over not less than 1/4 of an hour and at a temperature of not higher than 60°C.