| Abstract: | Methods for the synthesis of tri- and tetranitro-substituted 5,9-dioxo-4,5,9,10-tetrahydro-4,10-dioxapyrenes, 5,10-dioxo-4,5,9,10-tetrahydro-4,9-dioxapyrenes, and 6H-dibenzob,d]pyran-6-one were developed in a search for effective sensitizers for electrophotographic layers based on carbazole-containing polymers. The possibility of the production of nitro compounds that contain three vicinal nitro groups was demonstrated. Under severe nitration conditions 2,4,8-trinitro-6H-dibenzob,d]pyran-6-one is cleaved to give 2-hydroxy-2 -carboxy-3,5,4-trinitro-biphenyl, which is resistant to cyclization to give the starting compound, evidently because of the existence of an intramolecular hydrogen bond between the hydroxy group and the nitro group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 463–467, April, 1985. |
