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

In the title compound, C18H17NO3S, the seven-membered thia-zepine ring adopts a slightly distorted sofa conformation. The dihedral angle between the mean plane of the benzothia-zepine ring system and the benzene ring is 5.9 (1)°. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯S hydrogen bond, which generates an S(7) ring motif. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds link inversion-related mol-ecules into dimers, incorporating R 1 (2)(6) and R 2 (2)(8) ring motifs; the acceptor O atom is bifurcated. These dimers are further linked by C-H⋯O hydrogen bonds, forming supra-molecular tapes running along the a axis. These are connected into the three-dimensional architecture by C-H⋯π inter-actions.