PROCESS FOR PRODUCING LOW-MELTING CRYSTAL OF FREE DISOPYRAMIDE BASE

摘要

A process for producing low-melting crystals of a free disopyramide base which comprises the step of dissolving in a solvent the free disopyramide base represented by the following formula, the step of crystallizing the base from the solution obtained, and the step of aging the crystals, characterized in that the solvent is a mixed solvent comprising toluene and one or two hydrocarbon solvents selected between heptane and hexane. The process enables low-melting crystals of a free disopyramide base to be stably produced in high yield on an industrial scale.