Abstract
In the molecule of the title compound, C7H9ClN2O2, the conformation is determined by intramolecular C-H center dot center dot center dot O and C-H center dot center dot center dot Cl hydrogen bonds, which generate S(6) and S(5) ring motifs. The isopropyl group is almost perpendicular to the pyrimidine ring with torsion angles of -70.8 (3) and 56.0 (3)degrees. In the crystal, two inversion-related molecules are linked via a pair of N-H center dot center dot center dot O hydrogen bonds into R-2(2)(8) dimers; these dimers are connected into chains extending along the bc plane via an additional N-H center dot center dot center dot O hydrogen bond and weaker CH center dot center dot center dot O hydrogen bonds. The crystal structure is further stabilized by a weak pi-pi interaction [3.6465 (10) angstrom] between adjacent pyrimidine-dione rings arranged in a head-to-tail fashion, producing a three-dimensional network.