METHOD FOR PRODUCING HIGH-PURITY PEMIROLAST

摘要

PROBLEM TO BE SOLVED: To a new method for the purification of pemirolast, whose potassium salt is an anti-allergic pharmaceutical product. SOLUTION: This method comprises the salification of acid form pemirolast in the presence of an amount of a primary or secondary amine ranging from 1 equivalent to 1.5 equivalents relative to pemirolast and an amount of protic solvents such as water, 1-3C alcohols or mixtures thereof ranging from 1 volume to 10 volumes relative to pemirolast.