(2Z)-3-(4-Chloro­anilino)-1-(5-hy­droxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)but-2-en-1-one

With the exception of the terminal benzene rings, the atoms in the title compound, C(20)H(18)ClN(3)O(2), are approximately coplanar (r.m.s. deviation = 0.0495 Å). The benzene/chloro­benzene rings form dihedral angles of 3.02 (4) and 41.59 (5)°, 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⋯O and N—H⋯O hydrogen bonds that close S(6) rings. The configuration about the 2-butene bond is Z. Supra­molecular chains mediated by C—H⋯Cl inter­actions and aligned along the c axis are found in the crystal packing. These assemble into layers that are connected by weak π–π inter­actions between centrosymmetrically related chloro­benzene rings [3.8156 (9) Å].