Ethyl (2Z)-2-(3-methoxy-benzyl-idene)-7-methyl-3-oxo-5-phenyl-2,3-dihydro-5H-1,3-thia-zolo[3,2-a]pyrimidine-6-carboxyl-ate.

In the title compound, C(24)H(22)N(2)O(4)S, the central pyrimidine ring is significantly puckered, assuming a conformation inter-mediate between a boat and a screw boat. The nearly planar thia-zole ring (r.m.s. deviation = 0.0258†à ) is fused with the pyriamidine ring, making a dihedral angle of 9.83†(7)°. The carboxyl group is in an extended conformation with an anti-periplanar orientation with respect to the dihydropyrimidine ring. The benzene ring linked at the chiral C atom is perpendicular to the pyrimidine ring [dihedral angle = 85.21†(8)°] whereas the phenyl ring is nearly coplanar, making a dihedral angle of 13.20†(8)°. An intra-molecular C-H⋯S hydrogen bond is observed. The crystal packing is influenced by weak inter-molecular C-H⋯π inter-actions and π-π stacking between the thia-zole and phenyl rings [centroid-centroid distance = 3.9656†(10)†à ], which stack the mol-ecules along the c axis.