G. Yadav, Ginish George
Sep 17, 2008
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Influential Citations
26
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Journal
Journal of Molecular Catalysis A-chemical
Abstract
Abstract Hydroxybenzophenones are important precursors used in fine chemical and pharmaceutical industries. The esterification reaction of phenol with benzoic acid, followed by the Fries rearrangement towards hydroxybenzophenones in a one-pot liquid phase operation was examined with several catalysts under solvent-free conditions. Cesium substituted dodecatungstophosphoric acid supported on K-10 clay (designated as Cs2.5H0.5PW12O40/K-10) was found to be the most active and selective catalyst towards 4-hydroxybenzophenone in comparison with others. The order of activity was as follows: 20 % w/w C s 2.5 H 0.5 P W 12 O 40 /K- 10 ( most active ) ∼ ( almost equal ) UDCaT- 5 > 20 % w/w C s 2.5 H 0.5 P W 12 O 40 /HMS > UDCaT- 6 ( least ) . The conversion of benzoic acid and selectivity for 4-hydroxybenzophenone at a phenol to benzoic acid mole ratio of 7:1, using 0.05 g/cm3 Cs2.5H0.5PW12O40/K-10 at 200 °C were 70% and 32.5%, respectively. The effects of various reaction parameters on the rate of reaction and selectivity were investigated.