(E)-5-[(2-Hydroxy-5-methoxybenzylidene)amino]-1,3,4-thiadiazole-2(3H)-thione

In the title thione–Schiff base compound, C10H9N3O2S2, the dihedral angle between the benzene ring and the five-membered ring is 6.69 (8)°. An intramolecular O—H⋯N hydrogen bond forms an S 2 2(6) ring. In the crystal, inversion dimers linked by pairs of N—H⋯S interactions occur, generating R 2 2(8) ring motifs. The crystal structure features a S⋯S contact [3.3776 (7) Å], which is significantly shorter than the sum of the van der Waals radii (3.7 Å). The crystal structure also features C—H⋯O and π–π interactions [centroid–centroid distances = 3.4636 (9)–3.808 (1) Å].