Chemistry of furazano[3,4-b]pyrazine. 1. Synthesis and thermodynamic appraisal of 4,8-dihydrodifurazano[3,4-b,e]pyrazine and its derivatives

The thermodynamic stability of the antiaromatic 4,8-dihydrodifurazano[3,4-b,e]pyrazine (I) was studied by a quantum-chemical method. The molecular structure was investigated by x-ray crystallographic analysis, and the aromaticity index of the compound was calculated. It was shown that the oxidation or nitration of compound (I) leads to a stable aromatic radical.Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 250–264, February 1997.