Triethylamine (0.75 g, 0.0072 mol.) was added to a solution of iodoacetamide (0.59 g, 0.0032 mol.) and 1,2-dihydro-4-phenyl-8-piperazinylimidazo[1,2-a]quinoxaline 5-oxide (1.0 g, 0.0029 mol.) in ethanol (50 ml) and the reaction mixture stirred overnight at room temperature. The resulting precipitate was removed by filtration, washed with ethanol and then ether. Recrystallization from ethanol yielded 2-[4-(1,2-dihydro-5-oxido-4-phenylimidazo[1,2-a]-quinoxalin-8-yl)piperazinyl]acetamide, (0.63 g) as bright yellow crystals, m.p. 225°-227° C. (Found: C, 63.50; H, 5.89; N, 19.72%; C22H24N6O6.O.75H2O requires C, 63.23; H, 6.11; N, 20.12%) represented by the structural formula: ##STR32##
