METHOD OF PREPARING A RISEDRONATE

摘要

A method for preparing risedronate is provided to improve homogeneity of reaction and to prevent the generation of heat of neutralization by using 1,4-dioxane as a solvent, thereby enhancing yield. A method for preparing risedronate comprises the steps of dissolving 3- pyridyl acetic acid or its salt and hypophosphoric acid in 1,4-dioxane as a reaction solvent; adding a phosphorus trihalide to the obtained solution and heating it for reaction; hydrolyzing the reaction product; and crystallizing the hydrolyzed product.