PURPOSE: To obtain a proline ester convertible to proline (amino acid) chemically or biochemically in high yield by one stage from a butyric acid derivative, by reacting a 2-cyanoethylglycine ester with hydrogen in the presence of a palladium catalyst.
CONSTITUTION: A 2-cyanoethylglycine ester shown by the formula I (R is lower alkyl, etc., especially ethyl) is reacted with hydrogen in the presence of a palladium catalyst to give a proline ester shown by the formula II advantageously. The starting substance, for example, is obtained by subjecting acrylonitrile to Michael addition to a Schiff base of glycine ester and benzophenone, hydrolyzing the reaction product in the presence of an acid, and it may be in the form of a salt such as hydrochloride, etc.
IMAMURA SHINZOU
SATOU HARUYO
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