AN IMPROVED PROCESS FOR THE PREPARATION OF BIPHOSPHONIC DERIVATIVES

摘要

The present invention provides a novel process for preparation of bisphosphonic acid derivatives or pharmaceutical acceptable salt thereof, by reacting carboxylic acid having structural formula (II) with phosphorous acid and a halophosphorous compound, wherein halophosphorous compound is selected from the group comprising of PCl₃, PCl₅, POCl₃, PBr₃, POBr₃, and PBr₅ in presence of diphenyl ether.