Jun Hiratake,Bunta Watanabe,Ryuzo Yoshioka,Hideaki Ishida
申请号：
US16333084
公开号：
US10774098B2
申请日:
2017.09.12
申请国别(地区):
US
年份:
2020
代理人:
摘要：
Provided is a method for separating the four optical isomers of Nahlsgen. The method according to the present invention for producing a mixture of a D-2-amino-4-[(Rp)-(3-carboxymethylphenoxy)(methoxy)phosphoryl]butanoic acid hydrate and an L-2-amino-4-[(Sp)-(3-carboxymethylphenoxy)(methoxy)phosphoryl]butanoic acid hydrate includes subjecting a mixture of the four optical isomers, represented by Formula (1′；), to fractional crystallization from water or from a solvent mixture of water and a water-soluble organic solvent, to precipitate a mixture of a compound represented by Formula (1-1′；-1) and a compound represented by Formula (1-4′；-1), where Formulae (1′；), (1-1′；-1), and (1-4′；-1) are expressed as follows:
