(Z)-3-(2,4-Dichloro­benz­yl)-1,5-benzo­thia­zepin-4(5H)-one

In the title compound, C(16)H(11)Cl(2)NOS, the seven-membered thia­zepine ring adopts a distorted twist-boat conformation. The dihedral angle between the mean plane of the benzothia­zepine ring system and the benzene ring is 78.6 (1)°. The mol­ecular conformation is stabilized by a weak intra­molecular C—H⋯Cl hydrogen bond, which generates an S(5) ring motif. In the crystal, pairs of N—H⋯O hydrogen bonds link inversion-related mol­ecules into dimers, generating R (2) (2)(8) ring motifs. The crystal packing also features alternating π–π inter­actions between benzothia­zepine benzene rings [inter-centroid distance = 3.740 (3) Å] and dichloro­benzene rings [inter-centroid distance = 3.882 (3) Å] to consolidate a three-dimensional architecture.