| Abstract: | Heating 3,8-dinitro-10-carboxy-6H-dibenzob,d]pyran-6-one in DMSO, DMF, or HMPTA leads to decarboxylation and the replacement of the carboxyl group by a hydroxy group with the formation of 3,8-dinitro-6H-dibenzob,d]pyran-6-one and 3,8-dinitro-10-hydroxy-6H-dibenzo b,d]pyran-6-one. The decarboxylation of 2,7-dinitro-5,10-dioxo-4,5,9,10-tetrahydro-4,9-dioxapyrene in HMPTA is preceded by opening of the two lactone rings and the formation of a 1:4 molecular complex of 4,4 -dinitro-6,6-dihydroxy-2,2-dicarboxybiphenyl with HMPTA, whose structure was established by x-ray diffraction structural analysis.Translated from Khimiya Geterotsiklicheskik Soedinenii, No. 2, pp. 164–170, February, 1989. |
