Patent ID: 7462712

Claim:
A process for the preparation of imipenem of Formula I the process comprising: a) activating a keto ester compound of Formula II, wherein R is a protecting group with a phosphorohalidate of Formula VI wherein X is a halogen atom and R′ is phenyl, in the presence of a base and a catalytic amount of a dialkylaminopyridine to obtain enol phosphate compound of Formula III, wherein R and R′ have the same meaning as defined above, b) reacting the enol phosphate intermediate of Formula III, in situ with 2-aminoethanethiol or an acid addition salt thereof to get thienamycin ester of Formula IV, wherein R has the same meaning as defined above, c) reacting thienamycin ester of Formula IV in situ with benzyl formimidate or an acid addition salt thereof in the presence of a base to get carboxyl protected imipenem of Formula V, wherein R has the same meaning as defined above, and d) hydrogenating the carboxyl protected imipenem of formula V obtained from step c), without isolation or purification, in an aqueous medium to obtain imipenem.