PROCESS FOR PRODUCING LOW-MELTING CRYSTAL OF FREE DISOPYRAMIDE BASE

摘要

The present invention provides a production method of a low melting point type crystal of disopyramide free base, which comprises a step of dissolving disopyramide free base in a solvent, a step of crystallizing the disopyramide free base from the obtained solution and a step of aging the crystal of the disopyramide free base, wherein the solvent is a mixed solvent of toluene and one or two kinds of hydrocarbon solvents selected from heptane and hexane. According to the present invention, a method capable of stably producing a low melting point type crystal of disopyramide free base on an industrial scale in a high yield can be provided.