Regio-selective benzoylation of xylenes over caesium modified heteropolyacid supported on K-10 clay

Abstract

Benzoylation of xylenes leads to different dimethyl benzophenone isomers which are important intermediates for a variety of industries including pharmaceuticals, fine chemicals, agrochemicals, explosives, polymers, antioxidants, etc. It is possible to prepare these ketones selectively and economically from commercial mixed xylenes under different sets of conditions because of the preferential reactivities of xylene isomers in the presence of solid acid catalysts. The regioselective benzoylation of pure xylene isomers and also of mixed xylenes was studied with benzoyl chloride over Cs_2.5H_0.5PW₁₂O₄₀/K-10 supported on K-10 montmorillonite clay as the catalyst. This is a novel catalyst, which could be reused without any further chemical treatment, eliminating the effluent disposal problems. This also forms the basis for the separation of individual xylene components.