PROCESS FOR PRODUCING alpha -L-ASPARTYL-L-PHENYLALANINE METHYLESTER HYDROCHLORIDE

摘要

The present invention relates to a process for producing alpha - L-aspartyl-L-phenylalanine methylester hydrochloride from N-protected alpha -L-aspartyl-L-phenylalanine methylester, and the process comprises the steps of; adding toluene, water or toluene/water to the N-protected alpha -L-aspartyl-L-phenylalanine methylester reaction mixture containing acetic acid/toluene, while controlling not to cause layer separation; removing acetic acid and toluene in the reaction mixture by reduced-pressure distillation; then producing alpha -L-aspartyl-L-phenylalanine methylester hydrochloride by adding aqueous hydrochloride and methanol to above obtained syrup or oil state of N-protected alpha -L-aspartyl-L-phenylalanine methylester.