OXIDATION OF BENZYL ALCOHOL USING HYPOCHLORITE ION VIA PHASE-TRANSFER CATALYSIS

Heterogeneous oxidation of benzyl alcohol using hypochlorite ion with phase-transfer catalyst is carried out in an agitated vessel with a flat interface. Cetyltrimethylammonium bromide and toluene are chosen as the best catalyst and solvent, respectively. Observed reaction rates are proportional to the interfacial concentration of cetyltrimethylammonium hypochlorite in the organic phase, which is formed by ion exchange between bromide and hypochlorite ions. They are reasonably explained by the proposed theoretical model for the phase-transfer catalysis. The reaction rate constant evaluated by fitting the rate data to the model prediction is 22.7 m(3)/kmol.s at 303 K, independent of the physical properties in the aqueous solutions. The maximum yield of benzaldehyde is about 90% and the selectivity is 100% for the conversion of hypochlorite ion less than 80%.