An efficient catalyst-free protocol for the synthesis of quinoxaline derivatives under ultrasound irradiation

A highly efficient and facile method has been described for the synthesis of quinoxaline derivatives in good to excellent yields (80-99%) by condensation reaction of heterocyclic as well as aliphatic 1,2-diketones (R1COCOR1, R1 = Et, Ph, p-MeC6H5, p-MeOC6H5, Furyl) with 1,2-diamines (1,2-(NH2)2C6H3R2, R2 = H, Br, NO2, PhCO). A systematic study was carried out to examine the influence of reaction media and electronic factors of the substrates on the reaction results. (author)