Patent ID: 7098329
Filing Date: 2006-08-29
Classification: C07D

Abstract:
1. An improved process for the preparation of ceftriaxone sodium of formula (I), which comprises the steps of: i) reacting the 3-cephem derivative of formula (II) with halo acid derivative of formula (III) wherein X represents halogen atom and Y represent a halogen atom or an activating groups in the presence of a silylating agent and methylene chloride at a temperature in the range of −25 to 10° C., ii) quenching the reaction by pouring the reaction mixture into water or in a solution of sodium carbonate in water, to produce a compound of formula (IV), iii) preparing sodium salt solution of the compound of formula (IV) by adding sodium carbonate and separating the organic layer, iv) cyclizing the sodium salt of the compound of formula (IV) in the water solution with thiourea at a temperature in the range of 0 to 30° C., v) adjusting the pH to 1.5 to 2.5 to precipitate the ceftriaxone free acid, vi) converting the ceftriaxone free acid to sodium salt using sodium-2-ethyl hexanoate in water and vii) precipitating and isolating the cefiriaxone sodium of formula (I) using a solvent.