The asymmetric unit of the title compound, C 21 H 28 N 4 O, consists of two unique molecules linked by an O—H...N hydrogen bond. The conformation of both C=N bonds is E and the azomethine functional groups lie close to the plane of their associated benzene rings in each of the independent molecules. The dihedral angles between the two benzene rings are 83.14 (4) and 75.45 (4)°. The plane of the one of the N(CH 3 ) 2 units is twisted away from the benzene ring by 18.8 (2)°, indicating loss of conjugation between the lone electron pair and the benzene ring. In the crystal structure, O—H...N hydrogen bonds together with C—H...O hydrogen bonds link neighbouring supramolecular dimers into a three-dimensional network.