Synthesis of imidazo- and diimidazo[1,2,4,5]tetrazines; for tautomerism of dihydro-1,2,4,5-tetrazines

Article abstract of DOI:10.1055/s-1992-26251

Dimethyl 1,4-dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate (1) reacts with isocyanates to afford the 2,7-disubstituted 1H,6H-diimidazo[1,5-b:1',5'-e][1,2,4,5]tetrazine-1,3,6,8(2H,7H)-tetron es 2a-m, a hitherto unknown ring system. The linear annulation of 2