Synthesis and Structure of Dimethyl 3,6-Diphenyl-1,2- Dihydro-1,2,4,5-Tetrazine-1,2-Dicarboxylate

Dimethyl 3,6-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2-dicarboxylate was prepared from methyl chloroformate and 3,6-diphenyl-1,2(or 1,4)-dihydro-1,2,4,5-tetrazine and its structure elucidated by X-ray analysis. This reaction yields the title compound rather than dimethyl 3,6-diphenyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboxylate. The 2,3-diazabutadiene group in the central six-membered ring of tetrazine is not planar and the tetrazine ring has a twist conformation.