Patent ID: 8003820
Filing Date: 2011-08-23
Classification: C07F

Abstract:
1. A process for preparing a bisphosphonic acid having Formula I, wherein: X is a straight chain alkyl, a branched alkyl, or a cyclic alkyl chain having 1 to about 10 carbon atoms, which can optionally contain 1 to 3 nitrogen, oxygen, or sulfur atoms in the chain; and Y is an alkyl, aralkyl, aromatic or hetero aromatic group, which can be optionally substituted by a group having a formula: wherein R 1 and R 2 are independently hydrogen or straight chain, branched, or cyclic alkyl groups, each independently having 1 to about 10 carbon atoms; or a salt thereof, comprising reacting a carboxylic acid with a phosphonating agent consisting essentially of a combination of phosphorous acid and at least one of phosphorous trichloride, phosphorous pentachloride, phosphorous pentachloride, phosphorous tribromide, phosphorous pentabromide, and phosphorous oxybromide, in a cresol solvent.