Process for producing L-carnitine from D,L-carnitine nitrile salts

US5166426A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Harald Jakob · Hasselroth, DE
• Klaus Huthmacher · Gelnhausen, DE
• Herbert Klenk · Hanau, DE

Key dates

• Filing date: Mar 27, 1992
• Grant date: Nov 24, 1992
• Expiry date: Mar 27, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C227/34
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Synthesis of L-carnitine by chemical optical resolution of D,L-carnitine nitrile salts, where the D,L-carnitine nitrile salt is reacted with optically active N-acetylproline as the resolving agent in order to form the diastereomer salts after conversion to the hydroxide form, one of the two diastereomer salts is separated by fractional crystallization and the fraction containing mainly L-carnitine nitrile salt is treated with an optically inactive strong acid in order to split off the optically active N-acetylproline and then the resolving agent is separated and the resulting L-carnitine nitrile salt is saponified to L-carnitine. N-acetyl-L-proline is used as the resolving agent and the diastereomer (LL) salt is obtained in crystalline form in a high optical purity by fractional crystallization and the L-carnitine nitrile salt obtained after splitting off and separating N-acetyl-L-proline is used directly for saponification without further crystallization.