2-Dicyclo­hexyl­amino-3-phenyl-5,6-di­hydro-8H-thio­pyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4(3H)-one

In the title compound, C(27)H(33)N(3)OS(2), the dihedral angle between the two fused rings of the thieno[3,2-d]pyrimidine system is 3.73 (9)°. The phenyl ring is twisted with respect to the pyrimidine ring [dihedral angle = 71.60 (10)°] and the thio­pyran ring shows an envelope conformation with the S atom as the flap. An intra­molecular C—H⋯O inter­action occurs. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds occur.