Crystal of enantiomer pair of phenylacetic acid ester derivative and process for obtaining a mixture of stereoisomers of the derivative

摘要

A crystal of an enantiomer pair of stereoisomers of alpha -cyano-3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate (general name: fenvalerate) comprising (S)- alpha -cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)isovalerate and an enantiomer thereof, which has the crystal characteristics as specified in the specification, is disclosed. A process for preparing the enantiomer pair or the fenvalerate rich in the enantiomer pair by depositing the above-described crystal from a solution of a racemate of fenvalerate is also disclosed. A process for preparing the enantiomer pair by depositing the crystal from a solution of the fenvalerate rich in the enantiomer pair is further disclosed.