2-(1H-Imidazol-1-yl)-3-isopropyl-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

In the title compound, C(16)H(14)N(4)OS, the three fused rings of the benzothieno[3,2-d]pyrimidinone unit are essentially coplanar, the maximum deviation from the mean plane being 0.067 (3) Å. The dihedral angle between the mean plane of the fused rings and the imidazole ring is 72.00 (3)°. Offset π–π stacking inter­actions involving the fused rings are effective in the stabilization of the crystal structure. The centroid–centroid distances between the thienophene and benzene rings, and between the pyrimidine and benzene rings are 3.67 (1) and 3.93 (1) Å, respectively. There are two intramolecular C—H⋯O interactions.