Crystal structure of ethyl 2-acetyl-3,7-dimethyl-5-(thio-phen-2-yl)-5H-thia-zolo[3,2-a]pyrimidine-6-carboxyl-ate

In the title compound, C17H18N2O3S2, the pyrimidine ring adopts a shallow sofa conformation, with the C atom bearing the axially-oriented thio-phene ring as the flap [deviation = 0.439 (3) Å]. The plane of the thio-phene ring lies almost normal to the pyrimidine ring, making a dihedral angle of 79.36 (19)°. In the crystal, pairs of very weak C-H⋯O hydrogen bonds link the mol-ecules related by twofold rotation axes, forming R 2 (2)(18) rings, which are in turn linked by another C-H⋯O inter-action, forming chains of rings along [010]. In addition, weak C-H⋯π(thio-phene) inter-actions link the chains into layers parallel to [001] and π-π inter-actions with a centroid-centroid distance of 3.772 (10) Å connect these layers into a three-dimensional network.