Experimental

R factor = 0.037; wR factor = 0.097; data-to-parameter ratio = 12.2. The asymmetric unit of the title compound, C20H18N2O2, contains two independent molecules in which the dihedral angles between the naphthalene ring system [r.m.s. deviations = 0.012 (1) and 0.015 (1) Å] and the benzene ring are 71.65 (6) and 74.51 (6). In the crystal, pairs of N—H O hydrogen bonds form two independent inversion dimers with graph-set notation R2 2(14). In addition, each molecule contains an intramolecular O—H N hydrogen bond with an S(6) motif