SUCCINIC ACID DIESTER DERIVATIVE, PROCESS FOR PRODUCTION THEREOF, AND USE OF THE DERIVATIVE IN THE PRODUCTION OF PHARMACEUTICAL PREPARATION

摘要

Disclosed is a process for producing an optically active succinic acid imide derivative (3) which is a key intermediate for the production of ranirestat. The derivative (3) can be produced readily by treating a succinic acid diester derivative represented by the formula (2) with an alkali metal alkoxide. The derivative (3) can be used as a key intermediate for the production of ranirestat. (2) (3) wherein R<SUP>1</SUP> represents an amino group protected by a group which can be detached by hydrolysis or a tert-butoxycarbonylamino group; and R<SUP>2</SUP> represents an ethyl group which may be substituted by one or two methyl groups at the a-position, provided that when R<SUP>1</SUP> represents a tert-butoxycarbonylamino group, R<SUP>2</SUP> does not represent a tert-butyl group.