Patent ID: 7816119
Filing Date: 2010-10-19
Classification: C07C,C12P

Abstract:
1. A chemoenzymatic process for the stereoselective preparation of (R)-γ-amino-β-hydroxybutyric acid ((R)-GABOB) or (R)-carnitine comprising: i) forming a reaction mixture of 3,4-dihydroxybutanenitrile with dibutyltin oxide, p-toluenesulfonyl chloride and a base in an organic solvent, maintaining the reaction mixture at a temperature between 25-30° C. under a nitrogen atmosphere for 1-3 hours, thereby tosylating the 3,4-dihydroxybutanenitrile, adding water to the reaction mixture to form an organic layer and a water layer, separating the organic layer, concentrating and purifying the racemic 3-hydroxy-4-tosylbutanenitrile; ii) resolving the racemic 3-hydroxy-4-tosyloxybutanenitrile by reacting it with an acylating agent in an organic solvent catalyzed by a lipase at a temperature of 25-30° C., filtering and washing the resolved (R)-3-hydroxy-4-tosyloxybutanenitrile; iii) reacting the resolved (R)-3-hydroxy-4-tosyloxybutanenitrile with a base in an organic solvent under reflux, evaporating the solvent to produce a residue, adding concentrated HCl to the residue, heating to a temperature of 60-90° C. for about 6 hours, evaporating and purifying to obtain (R)-GABOB or (R)-carnitine.