Crystal structures of (E)-2-amino-4-methyl­sulfanyl-6-oxo-1-(1-phenyl­ethyl­­idene­amino)-1,6-di­hydro­pyrimidine-5-carbo­nitrile and (E)-2-amino-4-methyl­sulfanyl-6-oxo-1-[1-(pyridin-2-yl)ethyl­­idene­amino]-1,6-di­hydro­pyrimidine-5-carbo­nitrile

The title mol-ecule, C20H15NO3, adopts a Z-shaped conformation with the carboxyl group nearly coplanar with the di-hydro-quinoline unit. In the crystal, corrugated layers are formed by C-H⋯O hydrogen bonds and are stacked by C-H⋯π(ring) inter-actions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (43.3%), H⋯C/C⋯H (26.6%) and H⋯O/O⋯H (16.3%) inter-actions. The optimized structure calculated using density functional theory at the B3LYP/ 6-311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO-LUMO energy gap is 4.0319 eV.