Abstract
The title salt (systematic name: 2-methyl-4-oxo-3,4-dihydroquinazolin-1-ium chloride), C(9)H(9)N(2)O(+)·Cl(-), has ortho-rhom-bic (Pbcm) symmetry. Except for two methyl H atoms, all atoms of the mol-ecular cation are located about a mirror plane, making the quinazolinium moiety exactly planar. Individual mol-ecules are arranged in (001) layers in the crystal. Supra-molecular features include N-H⋯Cl hydrogen-bonding inter-actions, leading to zigzag chains along [010] with D (1) (1)(2) and C (1) (2)(6) graph-set motifs. Additionally, weak π-π stacking inter-actions occur between benzene rings in adjacent layers. Hirshfeld surface analysis revealed that the most important contributions to the surface contacts are from H⋯H (36.1%), H⋯C/C⋯H (25.8%), and H⋯O/O⋯H (17.7%) inter-actions.