Synthesis and structure of 7-methyl-5-phenyl-1H-pyrazolo[4,3-e]tetrazolo[4,5-b][1,2,4]triazine(1)

The synthesis of 5-azido-3-methyl-1-phenyl-1H-pyrazolo[4,3-e][1,2,4]triazine 2 and 7-methyl-5-phenyl-1H-pyrazolo[4,3-e]tetrazolo[4,5-b][1,2,4]triazine 3 is described and the crystal and molecular structure of the latter is reported. This compound crystallizes in the monoclinic system, space group P21/n, with cell constants a = 11.607(2) Å, b = 7.982(1) Å, c = 13.147(2) Å, β = 110.60(1)∘, Z = 4, T = 293 K and Dcal = 1.470 g cm−3. The structure was solved by direct methods and refined to R value of 0.0368 for 1906 reflections. The X-ray analysis revealed that the linear form of the tetrazolo-fused ring system of 3 exists in the crystal. The molecule as a whole has an almost planar conformation stabilized by the short intramolecular N⋅sH interaction. The molecular packing in the crystal is determined by the van der Waals forces only.