To provide a method for effectively producing an optically active butyric acid derivative useful as an intermediate, etc., for a medicine such as an agent for inhibiting platelet coagulation in high optical purity and high yield by treating a specific racemic butyric acid derivative with a specified optically active phenylethylamine derivative as a resolution agent in a specific condition.
The objective optically active butyric acid derivative having R-configuration or S-configuration of formula III is obtained by separating a racemic butyric acid derivative of formula I (Z is a protective group of an amino group) by using an optically active phenylethylamine derivative of formula II [X is nitro, a halogen or an alkyl; (n) is 0-5] having R-configuration or S-configuration as a resolution agent in 0.4-0.9mol based on 1mol racemic butyric acid derivative in the method for producing the optically active butyric acid derivative. Further, the racemic butyric acid derivative of formula I is preferably recovered by racemizing the needless optically active butyric acid derivative of formula III having the R-configuration or the S-configuration in the presence of a salt or an acid.
KUMAKUBO YUKIO
OSAWA MICHIYO
