Experimental

R factor = 0.048; wR factor = 0.121; data-to-parameter ratio = 15.3. In the title compound, C16H15N3O2H2O, the mean plane of the approximately planar pyrazole ring [maximum deviation = 0.0474 (18) Å] makes dihedral angles of 86.32 (11) and 45.04 (10) with the phenyl and pyridine rings, respectively. The dihedral angle between the phenyl and pyridine rings is 69.62 (11). In the crystal, intermolecular O—H O and O— H N hydrogen bonds connect the components into chains along [010]. The crystal structure is further stabilized by – stacking interactions with centroid–centroid distances of 3.7730 (12) Å. Related literature For standard values of bond lengths, see: Allen et al. (1987)