One-Pot Synthesis of Novel 3-(2-Oxo-2<i>H</i>-chromen-3-yl)-[1,3,4] Thiadiazino [2,3-<i>b</i>] Quinazolin-6 (2<i>H</i>)-ones Under Microwave Irradiation

An efficient one-pot synthesis of 3-(2-oxo-2H-chromen-3-yl)-[1,3,4] thiadiazino [2,3-b] quinazolin-6(2H)-ones in high yields has been developed by microwave-induced heterocyclization of 3-amino-2mercapto-3H-quinazolin-4-one when irradiated with 3-(2-bromo-acetyl)-chromen-2-one in ethanol and anhydrous potassium carbonate. A comparative study of conventional and MW methods is briefly discussed.