Synthése de la benzopyranno[1][2,3-b]quinoxalinone-12

3-Benzyl-2-quinoxalinones were obtained by condensation of o-phenyl-enediamine with phenylpyruvic acids. These quinoxalinones were easily substituted in position 2 and which permitted the preparation of many derivatives, however, cyclisation of these compounds into 12H-1]benzopyrano2,3-b]quinoxalines failed. This new heterocycle might be synthesized from ethyl 2-phenoxy-3-quinoxalinecarboxylate.