Heterocyclic Analogs of 5,12-Naphthacenequinone. 1. Synthesis of Heterocyclic Analogs Starting from 2,3-Diaminoquinizarine

The amination of 2-nitroquinizarine using hydroxylamine gives 2-amino-3-nitroquinizarine, which, upon reduction, gives previously unreported 2,3-diaminoquinizarine, a key intermediate in the synthesis of heterocyclic analogs of 5,12-naphthacenequinone, namely, 4,11-dihydroxyanthra[2,3-d]imidazole-5,10-dione (imidazoloquinizarine), 4,11-dihydroxyanthra[2,3-d][1,2,3]triazole-5,10-dione (triazoloquinizarine), and 5,12-dihydroxynaphtho[2,3-g]quinoxaline-6,11-dione (pyrazinoquinizarine). __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1081–1088, July, 2005.