Patent ID: 6903211
Filing Date: 2005-06-07
Classification: A61P,C07D,Y02P

Abstract:
1. An improved process for the preparation of cefprozil DMF solvate of formula (I) comprising the steps of: i) reacting the compound of formula (VIII) with acetaldehyde using lithium chloride in the presence of a solvent at a temperature in the range of −10° C. to 30° C. to produce a compound of formula (IX) wherein R 1 represents a carboxy protecting group, ii) deesterifying the carboxy protecting group of the compound of formula (IX) using an acid in the presence of a solvent at a temperature in the range of 10° C. to 50° C. to yield a compound of formula (X), iii) converting the compound of formula (X) to a compound of formula (XI) wherein M + represents a counter ion which forms a salt in the presence of a base and solvent, iv) neutralizing the compound of formula (XI) followed by enzymatic hydrolysis using conventional methods to produce the APCA of formula (V), v) silylating the APCA of formula (V) using a mixture of trimethyl silylchloride and hexamethyl disilazane in the presence of a halogenated solvent to produce silylated APCA of formula (XII) and vi) condensing the silylated APCA of formula (XII) with the mixed anhydride of formula (XIII) wherein R 2 represents alkyl, phenyl, benzyl or cycloalkyl and R 3 represents methyl, ethyl or isopropyl, in the presence of DMF, a halogenated solvent and a base at a temperature in the range of −50° C. to 10° C. to produce cefprozil DMF solvate of formula (I).