In the title compound, C(23)H(19)N(3)O(2), the dihedral angles formed by the pyrazolone ring with the three benzene rings are 30.91 (6), 60.96 (4) and 57.01 (4)°. The ligand is in the enamine-keto form and its structure is stabilized by an intra-molecular N-H⋯O hydrogen bond. In the crystal, O-H⋯N hydrogen bonds link mol-ecules into chains parallel to [01-1].

The mol-ecule of the title compound, [Ni(C(24)H(19)FN(3)O)(2)], has twofold rotation symmetry. The Ni(II) ion is in a square-planar coordination geometry which is distorted towards tetra-hedral and is coordinated by two N atoms of imine and two O atoms of pyrazolone from two Schiff base 4-[(Z)-(4-fluoro-benzyl-amino)phenyl-methyl-ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-onate ligands.

Ionic liquid 1,3-disulfonic acid imidazolium trifluoroacetate ([Dsim][TFA]) has been exploited as a highly efficient catalyst for the one-pot pseudo five-component reaction of phenylhydrazine (2 eq.) with ethyl acetoacetate (2 eq.) and arylaldehydes (1 eq.) in ethanol (reflux conditions). In this reaction, 4,4′‐(arylmethylene)‐bis(3‐methyl‐1‐phenyl‐1H‐ pyrazol‐5‐ol)s have been obtained in high ...

The asymmetric unit of the title compound, C(10)H(10)N(2)O, contains two crystallographically independent mol-ecules with similar geometries, which exist in the keto form. The C=O bond lengths are 1.2878 (12) Å in mol-ecule A and 1.2890 (12) Å in mol-ecule B, indicating that the compound undergoes enol-to-keto tautomerism during the crystallization process. In mol-ecule A, the pyrazole ring is ...