A PROCESS FOR PREPARING (R)-4-CYANO-3-HYDROXYBUTYRIC ACID ESTER
申请人:Samsung Fine Chemicals Co., Ltd.
公开号:EP1149068A1
公开(公告)日:2001-10-31
EP1149068A4
申请人:——
公开号:EP1149068A4
公开(公告)日:2003-01-02
US6586616B1
申请人:——
公开号:US6586616B1
公开(公告)日:2003-07-01
[EN] A PROCESS FOR PREPARING (R)-4-CYANO-3-HYDROXYBUTYRIC ACID ESTER<br/>[FR] PROCEDE DE PREPARATION DE DERIVES D'ESTER D'ACIDE (R)-4-CYANO-3-HYDROXYBUTYRIQUE
申请人:SAMSUNG FINE CHEMICALS CO LTD
公开号:WO2000046186A1
公开(公告)日:2000-08-10
The present invention relates to a process for preparing (R)-4-cyano-3-hydroxybutyric acid ester derivatives and more particularly, to a process for preparing optically pure (R)-4-cyano-3-hydroxybutyric acid ester derivatives expressed by formula (1) in high yield by performing cyanation and sequential esterification of (S)-3,4-epoxybutyric acid salt as a starting material. In said formula, R represents linear or branched alkyl group with 1∩5 carbon atoms or benzyl group.
Process for the preparation of R-(-)-carnitine
申请人:——
公开号:US20010031892A1
公开(公告)日:2001-10-18
R-(−)-carnitine is prepared by (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
1
-C
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], and finally (f) methylation of the amino group of compound [6] to yield the end product (R)-carnitine.