METHODS FOR PRODUCING NATEGLINIDE CRYSTALS

摘要

There is provided methods for producing nateglinide crystals, which comprises the steps of adding an acid(s) to a reaction mixture containing nateglinide to make it acidic, the reaction mixture being obtained by reacting trans-4-isopropylcyclohexylcarbonyl chloride with D-phenylalanine in a solvent mixture comprising a ketone solvent and water, in the presence of an alkali; and then adjusting the temperature of the mixture to 58°C to 72°c and the concentration of ketone solvent to more than 8wt% and less than 22wt% to conduct precipitation of nateglinide crystals. This producing method is the industrially beneficial methods for crystallization of nateglinide.