Synthesis of benzyl acetate with phosphotungstic acid ionic liquid as catalyst

Various liquid proton acids have been used as catalysts for the industry synthesis of benzyl acetate by esterification.However,these acids are extremely corrosive and contaminative and need to be neutralized at the end of the reaction.The phosphotungstic acid ionic liquid catalyst,recently reported,had the advantages of high acid activity,easy separation of catalyst and product,and the recovery and reuse of catalyst.In this paper,the esterification of acetate acid and benzyl alcohol was carried out using H3PW12O40、[MIM]3PW12O40,,and[MIMPS]3PW12O40as catalysts.The effects of amount of phosphotungstic acid ionic liquid catalyst,mole ratio of reactants,reaction temperature,and time on yields of benzyl acetate were investigated.The results showed that benzyl acetate can be obtained with 95.52% of yield under optimized conditions,0.2mol %catalyst,2 ∶1 molar ratio of acetic acid to benzyl alcohol,and at 110 ℃ for 5 h.Moreover,the catalyst could be reused continuously 5 times to give benzyl acetate in 84.15% of yield.Therefore,an environmental friendly approach for the synthesis of benzyl acetate was developed with the ionic liquid catalysts.