Synthesis of Indophenazino Fused Azacarbazole Derivatives of Biological Interest

Application of the Japp-Klingemann reaction on N-substituted-(3-hydroxymethylidine)-piperidin-4-one 6(a-d) with 4- indophenazine diazonium chloride (5) and 5-indophenazine diazonium chloride (9) yielded the corresponding 3-(4- indophenazinyl)-hydrazone of N-substituted piperidin-4-ones 7(a-d) and 3-(5-indophenazinyl)-hydrazone of Nsubstituted piperidin-4-ones 10(a-d) respectively. Fischer indolization of 7(a-d) and 10(a-d) hydrazones with Kent’s reagent (4:1 mixture of acetic acid:HCl) afforded N-substituted-2,3-dihydro-14H-azacarbazolo(2,3-b)-pyrazino(2,3-b)- 11H-indole-1-ones 8(a-d) and N-substituted-2,3-dihydro-14H-azacarbazolo(2,3-b)-6H-pyrrolo (3,2-b)-quinoxaline-1- ones 11(a-d) in moderate to good yield. All azacarbazole derivatives 8(a-d) and 11(a-d) were characterized on the basis of their microanalysis, IR, ¹H NMR and MS spectral data.