4-[(5-Chloro-2-hy-droxy-benzyl-idene)amino]-3-ethyl-1H-1,2,4-triazole-5(4H)-thione.

The title compound, C11H11ClN4OS, crystallizes with two mol-ecules, 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 mol-ecules feature an intra-molecular 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 inter-actions 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 R 2 (2)(8) loops.