PROCEDURES FOR THE MANUFACTURE OF E1-HYDROXY-2-(3-PYRIDINYL)ETHYLIdene bisphosphonic acid AND THEIR HEMIPENTAHYDRATE MONONATRIUM SALT

摘要

The invention relates to a novel process for the preparation of [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid and hemipentahydrate monosodium salt thereof comprising (a) reacting an aqueous solution of 3-pyridyl acetic acid hydrochloride with phosphorus trichloride; (b) removing unreacted phosphorus trichloride; (c) adding water and hydrolyzing; (d) isolating crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid; (e) suspending said crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid in water; (f) adding sodium hydroxide, filtering off, and washing; and (g) drying obtained hemipentahydrate monosodium salt of 1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid.