Abstract
The title compound, C10H13N3O2S, was prepared by condensation of 3,4-dihydroxybenzaldehyde with 4-ethyl-3-thiosemicarbazide. The molecule adopts an E configuration with respect to the C=N bond. One of the OH substituents on the dihydroxybenzene ring is disordered over the two possible 3-positions on either side of the ordered 4-hydroxy group. The occupancy of the major disorder component refined to 0.633 (7). The molecule is essentially planar, with an r.m.s. deviation through all non-H atoms of 0.0862 angstrom. An intramolecular N-H center dot center dot center dot N hydrogen bond forms between the outer amine residue and the imine N atom, generating an S(5) ring motif and contributing to the planarity of the molecule. In the crystal structure, an extensive network of classical O-H center dot center dot center dot O, O-H center dot center dot center dot S and N-H center dot center dot center dot S hydrogen bonds and weak C-H center dot center dot center dot O and S center dot center dot center dot O [3.301 (3) angstrom] interactions link molecules into sheets running approximately parallel to the ab plane.