Microwave assisted selective oxidation of lignin model phenolic monomer over SBA-15

Microwave assisted oxidation of the lignin model monomer apocynol, 1-(4-hydroxy-3-methoxyphenoxy)-ethanol was carried out over mesoporous SBA-15 catalyst using H2O2 as oxidant to produce acetovanillone, vanillin and 2-methoxybenzoquinone. Reaction conditions were optimised in order to obtain acetovanillone selectively, which serves as a raw material for 3,4-dimethoxybenzoic acid, a building block for synthesis of the smooth muscle relaxant mebeverin. Under conventional heating reactions were sluggish and gave poor yields of a mixture of products. The use of increased amount of catalyst resulted in lowering of acetovanillone selectivity. The possibility of recycling the catalyst was also studied. (C) 2008 Published by Elsevier B.V.