Pachaiyappan Abimannan, Venugopal Rajendran
Abstract: The ultrasound assisted preparation of 1, 4-bis (benzyloxy) benzene from the reaction of benzyl chloride (BC) and hydroquinone was carried out successfully using sodium hydroxide and catalyzed by a multi-site phase-transfer catalyst (MPTC) viz., 1, 4-dibenzyl-1, 4-diazoniabicyclo[2.2.2] octane dichloride in a solidliquid reaction condition (SL-PTC). Water is only introduced in a trace quantity to the reaction system to avoid a serious hydration of sodium salt of hydroquinone in the reaction. The reaction is greatly enhanced in the solidliquid system, catalyzed by multi-site quaternary ammonium salt (MPTC) and ultrasound irradiation (40 kHz, 300 W) in a batch reactor. The reaction mechanism is proposed and verified by examining the experimental evidence. A kinetic model is proposed in which a pseudo first-order rate law is sufficient to describe all the results.
Keywords: Multi-site phase-transfer catalyst, ultrasound irradiation, solid-liquid reaction, 1, 4-bis benzyloxy benzene, kinetics