Ammonium heptamolybdate tetrahydrate [(NH4)6Mo7O24.4H2O] efficiently catalyzes the condensation of aryl-1,2-diamines with 1,2-diketones in EtOH/H2O as a green media at room temperature to afford quinoxaline derivatives as biologically interesting compounds. Ease of recycling of the catalyst is one of the most advantages of the proposed method.