1-(2-Hy-droxy-eth-yl)pyrrole-2,5-dione.

The asymmetric unit of the title compound, C(6)H(7)NO(3), contains two mol-ecules (A and B) related by a non-crystallographic twofold pseudo-axis. The mol-ecules are joined in the (AABB)(n) manner by O-H⋯O hydrogen bonds between their hy-droxy groups, thus forming C(2) chains along the a-axis direction. Neighboring mol-ecules of the same kind (A and A, or B and B) are related by inversion centers, so that all hy-droxy H atoms are disordered other two sets of sites with half occupancies (superimposed O-H⋯O and O⋯H-O fragments). The mol-ecules are further linked by C-H⋯O inter-actions, which can be considered to be weak hydrogen bonds.