Kinetic Study of Synthesizing Bisphenol A Diallyl Ether in a Phase-Transfer Catalytic Reaction

Abstract

Abstract In the synthesis of bisphenol A diallyl ether from bisphenol A and allyl bromide, the liquid–liquid mode of operation catalyzed by quaternary ammonium salts was carried out in an alkaline solution/organic solvent two-phase medium. The mono-substituted product was not detected during or after the reaction. In this work, a rational reaction mechanism is proposed and a kinetic model then established. The apparent rate constant of the organic-phase reaction was obtained from experimental data. The effects of the reaction conditions, including agitation speed, organic solvents, quaternary ammonium salts, inorganic salts, temperature, alkali compounds, amount of potassium hydroxide, and water on the conversion of allyl bromide, were investigated in detail. The presence of a small amount of tetrabutylammonium bromide (TBAB) in the chlorobenzene/water system produced a rate over several folds larger than that of the reaction system in the absence of phase-transfer catalyst. The presence of alkali compounds promoted the formation of alkoxide and enhanced the extractive efficiency due to the salting out effect. The present etherification via phase-transfer catalyst could operate at lower temperatures to avoid Claisen rearrangement, which usually occurs at higher temperatures. Rational reasons to account for the absence of mono-substituted product are explained satisfactorily. Peculiar phenomena in investigating the effects of the volume of organic solvent, amount of KOH, and the volume of water and alkali compounds on the apparent rate constants are also explained.