Process of making D,L-lithium pantoate and resolving the racemic mixture into its optically active isomers

US4115443A · kind A · utility

Assignee

• VEB Jenapharm · DE

Inventors

• Joachim Schmidt · Schlangen, DE
• Christian Weigelt · Jena, DE
• Wolfgang Bamberg · Jena, DE
• Wolfgang Schneider · Marl, DE

Key dates

• Filing date: Mar 25, 1976
• Grant date: Sep 19, 1978
• Expiry date: Mar 25, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C59/105
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the resolution of optical isomers of racemic lithium pantoate by selective crystallization from a solution in methanol, ethanol, or other polar solvents, or by electrostatic separation. The optical isomers can be readily converted to optically active pantolactones which are the starting material for the preparation of optically active pantothenic acid and its salt and pantothenyl alcohol. One of the two optical isomers of each of these compounds possesses vitamin activity. The unwanted or inactive optical isomer of lithium pantoate as such is thermally stable and can be racemized by heating in the presence of a basic reacting compound at a temperature between 120 and 180.degree. C to produce a racemic mixture which can then be subjected directly to resolution without conversion to some other derivative in accordance with the processes of the present invention to produce the desired or active optical isomer.