1-(2-Hydroxyethyl)pyrrole-2,5-dione

The asymmetric unit of the title compound, C6H7NO3, contains two molecules (A and B) related by a non-crystallographic twofold pseudo-axis. The molecules are joined in the (AABB)n manner by O—H⋯O hydrogen bonds between their hydroxy groups, thus forming C(2) chains along the a-axis direction. Neighboring molecules of the same kind (A and A, or B and B) are related by inversion centers, so that all hydroxy H atoms are disordered other two sets of sites with half occupancies (superimposed O—H⋯O and O⋯H—O fragments). The molecules are further linked by C—H⋯O interactions, which can be considered to be weak hydrogen bonds.