Absolute configuration of (1S,2S)-3-methyl-2-phenyl-2,3-dihydrothiazolo[2, 3-b]quinazolin-5-one

The absolute structure of the molecule in the crystal of the title compound, C ₁₇H ₁₄N ₂OS, was determined by the refinement of the Flack parameter to 0.0 (2) based on 1011 Friedel pairs. The quinazoline ring is essentially planar, with a maximum deviation of 0.037 (2) Å. The thia-zole ring is distorted from planarity [maximum deviation = 0.168 (2) Å] and adopts a slightly twisted envelope conformation, with the C atom as the flap atom. The central thia-zole ring makes dihedral angles of 7.01 (8) and 76.80 (10)° with the quinazoline and phenyl rings, respectively. The corresponding angle between the quinazoline and phenyl rings is 3.74 (9)°. In the crystal, there are no classical hydrogen bonds but stabilization is provided by weak C-H⋯π inter-actions, involving the centroids of the phenyl rings.