Studies on catalytic synthesis of the flavor ethyl benzonate under microwave irradiation

With benzoic acid and ethanol as raw materials,cyclohexane as water-carrying agent and nanometer rare earth composite solid superacid SO2-4/ZrO2-Nd2O3 as catalyst,ethyl benzoate was synthesized directly under normal pressure and microwave irradiation.The factors that had influence on the reaction were investigated.The most suitable reaction conditions were as follows: If the amount of benzoic acid was 0.05mol,the molar ratio of alcohol to acid was 3.5,the water-carrying agent was 5ml,the amount of catalyst was 1.0g,the power of microwave was 450W,and radiation time was 10min.Under these conditions,Esterification rate of over 97% was attained.In the process of experiment,The catalyst could be used repeatedly and regenerated.