Influence of bulky and halogen substituents on crystal packing of pyrazolo[1,5-a]pyrimidines

► Molecular and packing structures were determined by X-ray crystallography. ► Cl⋯Cl, Cl⋯Br and Cl⋯N were found as main intermolecular interactions. ► Halogen⋯π (pyrazole/pyrimidine) interactions were described. ► The nature of interactions was explained by σ-hole concept.