PROCESS FOR SYNTHESIS OF (S) - PREGABALIN

摘要

Improved process for the synthesis of (S)-pregabalin having more than 99% ee through (S) 3-cyano-5-methyl-hexanoic acid has been developed. In addition to above, a novel process for resolution of (RS) - 3-cyano-5-methyl-hexanoic acid through diastereomeric salt formation with cinchonidine to obtain (S) - 3-cyano-5-methyl-hexanoic acid in high yield and high optical purity has been developed and furthermore process for recovery/ reuse of cinchonidine is also developed to improve the overall process efficiency.