2-[(Z)-(1-Naphth­yl)methyl­ene]benzimidazo[2,1-b]thia­zol-3(2H)-one

The title compound, C₂₀H₁₂N₂OS, was synthesized by mixing 2,4-dichloro­benzaldehyde, ethyl chloro­acetate and tetra­hydro­pyrimidine-2-thione in ethanol. The dihedral angle between the naphthalene plane and the heterocyclic ring system is 9.3 (3)°.