Experimental

R factor = 0.063; wR factor = 0.148; data-to-parameter ratio = 13.4. In the title molecule, C12H12N4O3S, there is an intramolecular O—H N hydrogen bond. The dihedral angle between the benzene and triazine rings is 65.9 (3). In the crystal, N— H S and O—H N hydrogen bonds link the molecules into chains along [010]. In addition, there are weak – stacking interactions between symmetry-related triazine rings with a centroid–centroid distance of 3.560 (3). Related literature For the biological activity of azomethine compounds, see