5-(4-Hy­droxy­phen­yl)imidazolidine-2,4-dione

The title compound, C₉H₈N₂O₃, was prepared by reaction of phenol, glyoxylic acid and urea in water. The imidazolidine ring adopts an almost planar conformation (r.m.s. deviation = 0.012 Å) and is twisted by 89.3 (1)° relative to the benzene ring. In the crystal, mol­ecules are linked by N—H...O and O—H...O hydrogen bonds into a three-dimensional framework.