PROCESS FOR SEPARATING THE ENANTIOMERS OF AMLODIPINE

摘要

PURPOSE: A method for isolating optical isomer from amlodipine racemic mixture is provided to obtain S-(-)-amlodipine and R-(+)-amlodipine optical isomer of highly optical purity and high yield. CONSTITUTION: A method for isolating S-(-)-amlodipine from (R,S)-amlodipine comprises: a step of reacting (R,S)-amlodipine of chemical formula 1 with D-tartarate in N-methyl pyrrolidone to obtain (S)-(-)-amlodipine-hemi-D-tartrate-mono-N-methyl pyrrolidone-solvate of chemical formula 2; and a step of neutralizing the obtained solvate with base in aqueous solution to obtain S-(-)-amlodipine of chemical formula 3. The N-methyl pyrrolidone is used in single or by mixing with co-solvent. The co-solvent is used in 50% v/v or less of reaction solvent.