Preparation of n-protected alpha-l-aspartyl-l-phenylalanine methyl ester
申请人:MITSUI TOATSU CHEMICALS, Inc.
公开号:EP0334236A2
公开(公告)日:1989-09-27
Disclosed are a process for preparing N-protected aspartic anhydride by the reaction of N-protected aspartic acid with phosgene, a process for preparing an N-protected α-L-aspartyl-L-phenylalanine methyl ester from N-protected aspartic anhydride and mineral acid salt of L-phenylalanine methyl ester, and a process for preparing N-benzyloxycarbonyl-L-aspartic anhydride by the reaction of N-benzyloxycarbonyl-L-aspartic acid with acetic anhydride.
Preparation and isolation of mineral acid salt of an amino methyl ester
申请人:MITSUI TOATSU CHEMICALS, Inc.
公开号:EP0376230B1
公开(公告)日:1994-11-23
US5113009A
申请人:——
公开号:US5113009A
公开(公告)日:1992-05-12
US5302743A
申请人:——
公开号:US5302743A
公开(公告)日:1994-04-12
Preparation and isolation of mineral acid salt of an amino acid methyl
申请人:Mitsui Toatsu Chemicals, Incorporated
公开号:US05113009A1
公开(公告)日:1992-05-12
A cyclical process for producing and isolating a mineral acid salt of an amino acid methyl ester in high purity and yield from the reaction solution produced by esterifying an amino acid with methanol in methanol in the presence of a mineral acid, by cooling the resulting reaction solution to precipitate crystals of the mineral acid salt; filtering the crystals; drying the isolated wet crystals or washing with another organic solvent; and recycling the filtrate for reuse in the esterification reaction.