Crystal structure and Hirshfeld surface analysis of 5-methyl-1,2,4-triazolo[1,5-a]pyrimidine.

The nine-membered ring system of the title compound, C6H6N4, is essentially planar. In the crystal, mol-ecules are linked via C-HTrz⋯NTrz and C-HPyrm⋯NTrz (Trz = triazole and Pyrm = pyrimidine) hydrogen bonds together with weaker C-HPyrm⋯NPyrm hydrogen bonds to form layers parallel to (02). The layers are further connected by π-π-stacking inter-actions between the nine-membered ring system [centroid-centroid = 3.7910 (8) Å], forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯N/N⋯H (40.1%), H⋯H (35.3%), H⋯C/C⋯H (9.5%), N⋯C/C⋯N (9.0%), N⋯N (3.1%) and C⋯C (3.0%) inter-actions and that hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. No significant C-H⋯π inter-actions are observed.