Preparation process of alpha-L-aspartyl-L-phenylalanine methyl ester or hydrochloride thereof
申请人:MITSUI TOATSU CHEMICALS, Inc.
公开号:EP0196866A2
公开(公告)日:1986-10-08
Disclosed herein is a process for preparing a-L-aspartyl-L-phenylalanine methyl ester or its hydrochloride from 5-benzyl-3, 6-dioxo-2-piperazine acetic acid or its methyl ester, prepared without using L-phenylalanine methyl ester which involves problems in its stability, as a raw material. Specifically, the process comprises: bringing 5-benzyl-3,6-dioxo-2-piperazine acetic acid in the presence of methanol or 5-benzyl-3,6-dioxo-2-piperazine acetic acid methyl ester in the presence or absence of methanol into contact with hydrochloric acid; isolating the thereby deposited a-L-aspartyl-L-phenylalanine methyl ester hydrochloride; and neutralizing said hydrochloride with an alkali as required. Preparation processes of 5-benzyl-3,6-dioxo-2-piperazine acetic acid or its methyl ester are also disclosed.
本发明公开了一种以 5-苄基-3,6-二氧代-2-哌嗪乙酸或其甲酯为原料制备 L-天冬氨酰-L-苯丙氨酸甲酯或其盐酸盐的工艺,该工艺不使用稳定性有问题的 L-苯丙氨酸甲酯作为原料。具体来说,该工艺包括:在有甲醇存在或无甲醇存在的情况下,将 5-苄基-3,6-二氧代-2-哌嗪乙酸或 5-苄基-3,6-二氧代-2-哌嗪乙酸甲酯与盐酸接触;分离由此沉积的 a-L-天冬氨酰-L-苯丙氨酸甲酯盐酸盐;以及根据需要用碱中和所述盐酸盐。此外,还公开了 5-苄基-3,6-二氧代-2-哌嗪乙酸或其甲酯的制备工艺。