Studies on vanadium catalyzed direct hydroxylation of aromatic hydrocarbons using hydrogen peroxide as oxidant

Direct hydroxylation of aromatic hydrocarbons, viz. benzene, toluene and anisole to phenol, cresols and methoxyphenols respectively has been studied by using hydrogen peroxide as oxidant and vanadium based systems such as vanadyl tetraphenoxyphthalocyanine, VO(acac)2, 20% V2O5/Al2O3, 14% V2O5/TiO2, 11% V2O5/ZiO2 as catalysts in acetonitrile under biphasic reaction conditions. Among the various vanadium-based catalysts studied, vanadyl tetraphenoxyphthalocyanine (VOPc) was found to be best from conversion as well as selectivity for hydroxy compounds points of view. The effect of various reaction parameters such as H2O2/substrate molar ratio, reaction temperature, solvent and catalyst concentration was systematically studied.