AZOLIUM SALTS AS EFFECTIVE CATALYSTS FOR BENZOIN CONDENSATION AND RELATED REACTIONS

A catalytic ability of several azolium salts for benzoin condensation, the benzoylation of 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine, a nd oxidative aroylation was examined. We found that azolium salts havi ng an imidazolium moiety, such as 1,4-dimethyl-1,2,4-triazolium iodide (3), and 2-methylpyrido[1,2-c]- (4), dipyrido[1,2-c:2',1'-e]- (5), na phtho[1,2-c]- (10), and phenanthro[9,10-c]imidazolium iodide (11) can be used as effective catalysts for benzoin condensation and related re actions.