Patent ID: 6646131
Filing Date: 2003-11-11
Classification: C07D

Abstract:
A method for the separation of (R)-(+)- and (S)-(âˆ’)-isomers of amlodipine from mixtures thereof, which comprises the reaction of the mixture of isomers with D- or L-tartaric acid as a chiral reagent, wherein the mole ratio of tartaric acid to amlodipine is 0.25, in a) hexadeuterium dimethyl sulphoxide (DMSO-d6) or b) an organic solvent containing DMSO-d6 for precipitation of, respectively, a DMSO-d6 solvate of D-tartrate salt of (S)-(âˆ’)-amlodipine, or a DMSO-d6 solvate of a L-tartrate salt of (R)-(+)-amlodipine.