Kinetic Study of Synthesising 2,4,6‐tribromophenyl Benzyl Ether by Phase Transfer Catalysis

Abstract The reaction of 2,4,6–tribromophenol and benzyl bromide in an alkaline solution of KOH/organic solvent by phase transfer catalysis was studied. The main product C6H5CH2O(C6H2)Br3 and the intermediate product Bu4N‐0(C6H2)Br3 were synthesised, and subsequently identified analytically. The kinetics of the reaction were studied in detail. The effects of the operating conditions such as agitating speed, amount of catalyst, types of solvent and catalyst, salt effects, amount of water, mole ratio of benzyl bromide to 2,4,6–tribromophenol, content of KOH and temperature, on the conversion and the reaction rates were investigated. The negligible mass‐transfer resistance of the catalyst between the two‐phase reaction was indirectly identified from experimental observations. The organic‐phase reaction is the rate‐controlling step for the two‐phase reactions. During the reaction, a constant concentration of the intermediate product was obtained in the organic phase. Therefore, a pseudo‐first‐order rate law can be applied to describe the two‐phase reaction. The activation energy for this reaction system was obtained as 18.31 kcal mol−1.