The rates of benzoin condensation catalyzed by thiazolium salts of varying structures have been determined in methanol containing triethylamine as the base by the method of gas chromatography. The condensation activity was observed not to be linearly correlated with the acidities of 2-position of catalyst thiazolium ring. The dimethylamino substituent was found not to act as an internal base for benzoin condensation, but rather exerted an ...