4-[(5-Chloro-2-hy­droxy­benzyl­idene)amino]-3-ethyl-1H-1,2,4-triazole-5(4H)-thione

The title compound, C₁₁H₁₁ClN₄OS, crystallizes with two mol­ecules, A and B, in the asymmetric unit in which the dihedral angles between the triazole and benzene rings are 54.6 (3) and 56.0 (3)°. Both mol­ecules feature an intra­molecular O—H...N hydrogen bond, which generates an S(6) ring. In the crystal, A–B dimers are linked by pairs of weak C—H...S hydrogen bonds along with π–π stacking inter­actions between the triazole rings [centroid–centroid separations = 3.631 (3) and 3.981 (4)Å]. N—H...S hydrogen bonds link the dimers into [100] chains, which feature R₂²(8) loops.