METHOD FOR PRODUCING (R)-4-CYANO-3-HYDROXYBUTYRIC ACID LOWER ALKYL ESTER

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently producing the subject compound in high purity. SOLUTION: This method for producing a (R)-4-cyano-3-hydroxybutyric acid lower alkyl ester comprises the following process: the objective reaction product is extracted several times using an organic solvent from a reaction liquid after cyanation of the corresponding (S)-4-halogeno-3-hydroxybutyric acid lower alkyl ester; wherein the extraction phases resulted from the 2nd extraction operation and thereafter are used as extraction solvent for other production lot(s).