2-tert-Butyl-5-methyl-7,8-dihydro-6H-cyclopenta[e]pyrazolo[1,5-a]pyrimidine: molecular stacks built from C-H...pi(pyrazole) hydrogen bonds and pi-pi stacking interactions.

In the title compound, C(14)H(19)N(3), the bond distances within the heterocyclic portion of the molecule indicate incomplete pi delocalization. The molecules are linked into stacks by a combination of two C-H...pi(pyrazole) hydrogen bonds and two independent pi-pi stacking interactions between inversion-related pyrimidine rings. The significance of this study lies in its observation of significant differences in both molecular conformation and supramolecular aggregation between the title compound, an example of a 2-alkylpyrazolo[1,5-a]pyrimidine, and some analogous 2-arylpyrazolo[1,5-a]pyrimidines.