The title compound, C11H8N2O3S, is roughly planar; the di-hedral angle between the planes of the thio-phene and benzene rings is 8.38 (10)°. An intra-molecular O-H⋯N hydrogen bond generates an S(5) ring motif. In the crystal, mol-ecules are linked into centrosymmetric dimers by pairs of O-H⋯O hydrogen bonds with an R 2 (2)(22) graph-set motif. Aromatic π-π stacking inter-actions [centroid-centroid sep-ar-ations = 3.653 (3) and 3.852 (3) Å] link the dimers into a three-dimensional network.
Keywords: Schiff bases; crystal structure; hydrogen bonding; phenol; π–π stacking.