Synthesis of diethyl malonate catalyzed by activated carbon supported tungstophosphoric acid under microwave irradiation

By using activated carbon supported tungstophosphoric acid as acatalyst,malonic acid and ethyl alcohol reacted to form diethyl malonate under microwave irradiation.The primary factors affecting the yield of esterfication were investigated.Results showed that the optimum conditions were as follows:when malonic acid was 0.15 mol,the molar ratio of ethyl alcohol to malonic acid was 2.8:1,the percentage of activated carbon supported tungstophosphoric acid was 35%and 1.30 g catalyst was used,microwave power 325 W, microwave irradiation 10 min,the agent taking of water amount of cyclohexane was 8.00 mL. Under these optimum experimental conditions,the yield of esterification reached to 97.6%. The experiments proved that activated carbon supported tungstophosphoric acid was a high active catalyst for diethyl malonate and could be reused under microwave irradiation.The reaction was 18 times faster under microwave irradiation than conventional heating.