Crystal structure of (Z)-2-hy­droxy-4-methyl-N′-(4-oxo-1,3-thia­zolidin-2-yl­idene)benzohydrazide trihydrate

In the title compound, C₁₁H₁₁N₃O₃S·3H₂O, the non-H atoms of the main mol­ecule are approximately planar, with an r.m.s. deviation of 0.030 Å. There is a bifurcated intra­molecular N—H...(O,S) hydrogen bond present forming S(6) and S(5) ring motifs. In the crystal, O—H...O and N—H...O hydrogen bonds link the molecules into a three-dimensional network.