8-(4-Chloro­phen­oxy)-7-(4-chloro­phen­yl)-1,2,5-trimethylthieno[2',3';2,3]pyrido[4,5-d]pyrimidin-6(7H)-one

In the mol­ecule of the title compound, C₂₄H₁₇Cl₂N₃O₂S, the mean plane of the tricyclic thienopyridopyrimidine system is roughly orthogonal to both benzene planes, the dihedral angles being 107.8 (1) and 99.6 (1)° for the benzene planes in the p-chloro­phen­oxy and p-chloro­phenyl groups, respectively. The dihedral angle formed by the two benzene rings is 101.4 (1)°.