Resolution of racemic verapamil

US5457224A · kind A · utility

Assignee

• Knoll, Inc. · DE

Inventors

• Oskar Ehrmann · Mannheim, DE
• Herbert Nagel · Schifferstadt, DE

Key dates

• Filing date: Jun 7, 1994
• Grant date: Oct 10, 1995
• Expiry date: Jun 7, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07B2200/07
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the resolution of racemic verapamil which comprises reacting the free base of the compound with optically active dibenzoyltartaric acid or ditoluoyltartaric acid in the molar ratio from 1:1 to 1:2 in a methanol/water mixture in the ratio from 1:1 to 3:1 or acetone/water mixture in the ratio from 0.5:1 to 2:1, separating the mixture of diastereomers obtained in this way by crystallization, and then converting the diastereomers into the free bases and these into their salts, if required, with physiologically tolerated acids.