3-[(E)-(4-Ethyl-phen-yl)imino-meth-yl]benzene-1,2-diol.

The title compound, C(15)H(15)NO(2), adopts the enol-imine tautomeric form. The dihedral angle between the two benzene rings is 48.1 (1)°. Intra-molecular O-H⋯N and O-H⋯O hydrogen bonds generate S(6) and S(5) ring motifs, respectively. In the crystal, mol-ecules are linked into centrosymmetric R(2) (2)(10) dimers via pairs of O-H⋯O hydrogen bonds and the dimers may interact through very weak by π-π inter-actions [centroid-centroid distance = 4.150 (1) Å]. The ethyl group is disordered over two orientations, with occupancies of 0.587 (11) and 0.413 (11).