Reactions of aza- and diazaanthraquinone N-oxides

Abstract 1-Azaanthracene-2,5,8-triones and 1,8-diazaanthracene-2,7,9,10-tetraones, which are structurally related to diazaquinomycin, are prepared by functionalization of azaathraquinone N -oxides. The complete procedure implies a Diels-Alder reaction as a key step, followed by N -oxidation and treatment of the N -oxides with benzoyl or tosyl chlorides in the presence of water.