Crystal structure of 6,9-dimethyl-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazepin-8(9H)-one 0.40-hydrate

In the mol-ecule of the title compound, C7H9N5O·0.40H2O, the seven-membered heterocyclic ring exhibits a boat conformation, whereas the five-membered triazole ring is almost planar (r.m.s. deviation = 0.005 Å). In the crystal, centrosymmetric dimers are linked by pairs of C-H⋯O hydrogen bonds into dimers, which are further connected via O-H⋯N and C-H⋯N hydrogen bonds, forming a three-dimensional network. The structure contains a partially occupied water mol-ecule lying on a twofold axis with an occupancy factor of 0.4.