Abstract
With the exception of the terminal benzene rings, the atoms in the title compound, C20H18ClN3O2, are approximately coplanar (r.m.s. deviation = 0.0495 angstrom). The benzene/chlorobenzene rings form dihedral angles of 3.02 (4) and 41.59 (5)degrees, respectively, with this plane. The hydroxy, amino and carbonyl groups all lie to the same side of the molecule, enabling the formation of intramolecular O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds that close S(6) rings. The configuration about the 2-butene bond is Z. Supramolecular chains mediated by C-H center dot center dot center dot Cl interactions and aligned along the c axis are found in the crystal packing. These assemble into layers that are connected by weak pi-pi interactions between centrosymmetrically related chlorobenzene rings [3.8156 (9) angstrom].