Study on synthesis of 4-methyl-5,7-dihydroxylcoumarin catalyzed by amino-sulfonic acid under microwave irradiation

The synthesis of 4-methyl-5,7-dihydroxyl coumarin was performed via the condensation of 1,3,5-benzenetriol and ethyl acetoacetate under microwave irradiation.The optimum reaction conditions were as follows:6.7 g of 1,3,5-benzenetriol,6.8 mL of ethyl acetoacetate,0.1 g of aminosulfonic acid,10 mL of cyclohexane were subjected to reaction for 12 min at 100 ℃ under microwave irradiation with a microwave power of 380 W.The product yield reached 89.2%.