Bisindoles. 6, Synthesis and investigation of some properties of 2-formyl-, 3-formyl-, and 3,8-diformyl-1H,6H-indolo[7,6-g]indoles

The formylation of 1H,6H-indolo[7,6-g]indole under the conditions of the Vilsmeier reaction at a molar ratio of the indoloindole and the Vilsmeier complex of 11 has made it possible to raise the yield of 3-formyl-1H,6H-indolo[7,6-g]indole to 43% and to also isolate 2-formyl-1H,6H-indolo[7,6-g]indole. The 1H,6H-indolo[7,6-g]indole molecule was subjected to quantum-chemical calculation by the CNDO (complete neglect of differential overlap) MO method. The formylindoloindoles were condensed with aniline, thiosemicarbazide, nitromethane, nitroethane, and hydroxyl-amine. The configurations of the isomeric dioximes of 3,8-diformyl-1H, 6H-indole[7, 6-g]indole were established by PMR spectroscopy.See [1] Communication 5.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1501–1507, November, 1980.