In the title compound, C(11)H(11)N(3)O(2)S(2), the dihedral angle between the benzene ring and the five-membered ring is 6.85 (9)°. An intra-molecular O-H⋯N hydrogen bond makes an S(6) ring motif. In the crystal, mol-ecules are linked through bifurcated N-H⋯(O,O) hydrogen bonds with R(1) (2)(5) ring motifs, forming chains along the b axis. A short C⋯S contact [3.3189 (19) Å], which is shorter than the sum of the van der Waals radii of these atoms (3.50 Å), occurs in the structure. The crystal structure is further stabilized by C-H⋯N hydrogen bonding and π-π inter-actions [centroid-centroid distance = 3.7649 (12) Å].