In the title compound, C(26)H(25)FN(4)OS, the thienopyrimidine fused-ring system is close to planar (r.m.s. deviation = 0.066 Å), with a maximum deviation of 0.1243 (17) Å for the N atom adjacent to the carbonyl group. This ring system forms dihedral angles of 67.5 (1) and 88.9 (1) ° with the adjacent six-membered rings. Inter-molecular C-H⋯O hydrogen bonding and C-H⋯π inter-actions help to stabilize the crystal structure.