PREPARATION PROCESS OF ALPHA-L-ASPARTYL-L-PHENYL-ALANINE METHYL ESTER HAVING LOW HYGROSCOPICITY

摘要

a-L-Aspartyl-L-phenylalanine methyl ester having low hygroscopicity is prepared by bringing a cake of a-L-aspartyl-L-phenylalanine methyl ester, which cake has been obtained by solid-liquid separation through a desired preparation process of a-L-aspartyl-L-phenyl-alanine methyl ester, into contact with an organic solvent of uniform phase so as to treat the cake with the organic solvent, subjecting the resulting mixture of the cake and organic solvent to solid-liquid separation to obtain a cake, and then drying the last-mentioned cake at a temperature not higher than 60.degree.C. The organic solvent is dry or contains water in an amount up to 30 wt.%.