PREPARATION PROCESS OF ALPHA-L-ASPARTYL-L-PHENYLALANINE METHYLESTER

摘要

1 to 20 parts by weight of methanol is solely added to 3-benzyl-6-carboxy methyl-2,3-diketopiperazine or M-L-aspartyl-phenyl alanine, thereafter 1 to 20 parts by weight of organic acid such as citric acid or strong acid such as chloric acid, sulfuric acid or phosphoric acid is admixed as catalyst to convert to M-APM at 40 to 60 degree Celsius. Said solution is further treated for removing methanol, controlled its pH at 4.8 to 5.2 to collect M-APM crystal.