The oxidation of penicillin‐G‐potassium salt using supported polyoxometalates with hydrogen peroxide

Abstract

Abstract. The oxidation of the sulfide group in penicillin G potassium salt to the sulfoxide with hydrogen peroxide has been investigated using a wide range of polyoxometalates immobilized on high-surface-area supports. The highest activity and selectivity for the sulfur oxidation of the penicillin compound was obtained with ammonium molybdate supported on to strongly basic anion-exchange resin. The oxidation proceeds smoothly at ambient and sub-ambient temperatures in water or water/alcohol solvents. The use of supported oxidation catalysts has been extended to the transformation of benzenethiol to benzenesulfonic acid which was found to proceed in high yield and selectivity employing phosphotungstic acid on y-alumina. The use of a supported catalyst with H ,02 as the primary oxidant allows the circumvention of environmental and product isolation problems to be overcome simply and economically.