METHOD FOR PRODUCING CILOSTAZOL

摘要

PROBLEM TO BE SOLVED: To provide an improved method for producing cilostazol and a method for purifying cilostazol by recrystallization. SOLUTION: The method for the production of cilostazol comprises the alkylation of the phenol group of 6-hydroxy-3,4-dihydroxyquinoline (6-HQ) with theδ-carbon of a 5-(4-halobutyl)-1-cyclohexyl-1H-tetrazole. The method is carried out by contacting a solution of the 5-(4-halobutyl)-1-cyclohexyl-1H-tetrazole in a water-immissible organic solvent with a trialkylammonium phase-transfer catalyst in a 6-HQ solution, a water-soluble base and water for a period sufficient for essentially completely converting the tetrazole to cilostazol and separating the produced cilostazol from the two-phase mixture. COPYRIGHT: (C)2006,JPO&NCIPI