Synthesis of Oxalic Ester With New Carbon-Based Solid Acid Catalyst Under Microwave Irradiation

A series of oxalic esters were synthesized from oxalic acid and n-butyl alcohol,isobutyl alcohol,n-amyl alcohol,isoamyl alcohol by using new carbon-based solid acid as catalyst under microwave irradiation.Effects of molar ratio of reactants,microwave irradiation power,microwave irradiation time and catalyst amount on esterification rate were discussed.The results show that esterification rates of different oxalic esters are above 95% under the optimal reaction conditions as follows: alcohol︰oxalic acid =4.0︰1,mass ratio of the catalyst to reactants 2.3%,microwave irradiation power 500 W,microwave irradiation time 12 min.The catalyst can be reused many times and esterification rate is unchanged.