Experimental

R factor = 0.030; wR factor = 0.089; data-to-parameter ratio = 32.5. The title compound, C7H6ClNO2, is almost planar, with an r.m.s. deviation of 0.040 Å. An intramolecular N—H O hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked into centrosymmetric dimers by pairs of O—H O hydrogen bonds. These dimers are stacked along [010]. Related literature For the pharmacological properties of quinazolinone deriva-tives, see: Prakash Naik et al. (2009); Bembenek et al. (2010); Miller et al. (2010); Sikorska et al. (1998). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986). For hydrogen-bond motifs, see: Bernstein et al. (1995)