In the title mol-ecule, C(9)H(10)BrN(3)O(2)S, the thia-zine ring has an envelope conformation with the S atom at the flap. The geometry around the S atom is distorted tetra-hedral. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds occur, generating R(2) (2)(6) ring motifs. N-H⋯O hydrogen bonds and C-H⋯O inter-actions connect the dimers, forming a three-dimentional network structure.