In the title compound C18H26BrNO2S, the thia-zepine ring adopts a boat conformation. The dihedral angle between the mean planes through the benzene ring and the four C atoms making up the basal plane of the boat is 35.8 (2)°. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R 2 (2)(8) loops.