PROCESS FOR PREPARING OPTICALLY PURE S-(-)-AMLODIPINE BENZENSULFONATE

摘要

PURPOSE: A method for preparing optically pure S-(-)-amlodipine benzensulfonate is provided to obtain pure S-(-)-amlodipine benzensulfonate using water only and prevent environmental pollution. CONSTITUTION: A method for preparing S-(-)-amlodipine-hemi-L-tartrate-monohydrate comprises: a step of adding S-(-)-amlodipine-hemi-L-tartrate-DMSO-solvate to the water of 30-35°C and stirring; a step of cooling reacted mixture and stirring for one to five hours; and a step of collecting precipitate. The S-(-)-amlodipine-hemi-L-tartrate-DMSO-solvate is (S)-(-)-amlodipine-hemi-L-tartrate-1/4-DMSO-solvate. A method for preparing S-(-)-amlodipine benzensulfonate comprises: a step of the S-(-)-amlodipine-hemi-L-tartrate-monohydrate to the water to obtain slurry solution; a step of adding benzene sulfonic acid solution to the slurry solution to form precipitate; and a step of collecting the precipitate.