title: 4-{(Z)-(sec-Butyl-amino)(phen-yl)methyl-ene}-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.
abstract: In the title compound, C(21)H(23)N(3)O, the dihedral angles formed by the pyrazolone ring with two phenyl rings are 10.38 (8) and 76.94 (6)°. The sec-butyl-amino group is disordered over two positions, with refined site-occupancy factors of 0.730 (4) and 0.270 (4). The compound could potentially be ligand stabilized in the solid state in a keto-enamine tautomeric form. The amine functionality is involved in an intra-molecular N-H⋯O hydrogen bond, while weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds participate in the formation of the crystal structure.
authors.forename: Hai-Zhen
authors.initials: HZ
authors.lastname: Xu
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Xu
authors.forename: Yan-Wei
authors.initials: YW
authors.lastname: Yuan
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.forename: You-Quan
authors.initials: YQ
authors.lastname: Zhu