Crystal structure of (5Z)-5-(2-hy-droxy-benzyl-idene)-1,3-thia-zolidine-2,4-dione.

The title compound, C10H7NO3S, crystallizes with four independent mol-ecules in the asymmetric unit with slightly different conformations; the dihedral angles between the six- and five-membered rings are 2.6 (1), 1.09 (9), 8.6 (1) and 6.2 (1)°. In the crystal, mol-ecules are linked by O-H⋯O and N-H⋯O hydrogen bonds, forming sheets lying parallel to (101).