PREPARATION PROCESS OF Ñß-ASPARTYL-L-PHENYLALANINE METHYLESTER

摘要

alpha -L-Aspartyl-L-phenylalanine methyl ester ( alpha -APM) is prepared by catalytic hydrogenation of N-benzyloxycarbonyl- alpha -L-aspartyl-L-phenylalanine methyl ester (Z- alpha -APM). The catalytic hydrogenation is conducted in an aqueous suspension containing the Z- alpha -APM in the form of particles whose average particle size is not greater than 800 mu m. The starting Z- alpha -APM may contain up to 30 wt.% of its beta -isomer provided that the process additionally includes recrystallization of the alpha -APM, collection of the alpha -APM by filtration and recycling of the filtrate for use in the aqueous suspension of Z- alpha -APM.