Patent ID: 7470786
Filing Date: 2008-12-30
Classification: C07D

Abstract:
1. A process for the preparation of ceftriaxone sodium of formula (II), comprising the steps of i) reacting a silylated compound of formula (III), with a 4-halo-2-methoxyimino-3-oxo-butyric acid derivative of formula (IV), wherein X and Y represent a halogen atom to give a compound of formula (V), ii) desilylating the compound of formula (V), wherein X is as defined hereinabove to give the desilylated compound of formula (VI), iii) reacting the desilylated compound of formula (VI) with thiourea in a solvent system containing organic solvent and water, to obtain ceftriaxone of formula (I), iv) converting the compound of formula (I) to the sodium salt (II); wherefore the improvement comprises i with a 4-halo-2-methoxyimino-3-oxo butyric acid derivative of formula (IV) having a purity of at least 95%, said 4-halo-methyloxyimino-3-oxo-butyric acid derivative containing 0.50% or less total di-brominated and poly-brominated impurity compounds, wherein X represents Br and Y represents Cl, in the presence of an inert water-immiscible organic solvent or mixtures thereof and in the presence of an acid scavenging agent at a temperature of between −10° C. to −0° C. to give a compound of formula (V), ii iii iv v wherein Q (vi