Patent ID: 6316667
Filing Date: 2001-11-13
Classification: C07B,C07C

Abstract:
Process for the preparation of R-(-)-carnitine according to the reaction diagram: ##STR2##where X is halogen and R a linear or branched C.sub.1 -C.sub.7 alkyl, comprising the following steps:a) conversion of (S)-3-hydroxy-4-butyrolactone [1] to alkyl (S)-4-halogen-3-hydroxy-butyrate [2] by reaction with a linear or branched C.sub.1 -C.sub.7 alcohol;b) substitution of a CN group for the halogen of compound [2] to yield the alkyl ester of (R)-4-cyano-3-hydroxybutyric acid [3];c) conversion of alkyl ester [3] to yield (R)-4-cyano-3-hydroxybutyramide [4];d) cyclization of compound [4] to yield (R)-5-(cyanomethyl)-2-oxazolidone [5] via conversion of the amide function to isocyanate;e) hydrolysis of compound [5] to yield (R)-4-amino-3-hydroxybutyric acid [6];f) methylation of the amino group of compound [6] to yield the end product (R)-carnitine.