title: Crystal structure of (4Z)-4-{[(2-chloro-phen-yl)amino](furan-2-yl)methyl-idene}-3-methyl-1-phenyl-4,5-di-hydro-1H-pyrazol-5-one.
abstract: In the title compound, C21H16ClN3O2, the pyrazolone ring and the O=C-C=C-N mean plane [maximum deviation = 0.022 (2) Å] are nearly coplanar, making a dihedral angle 4.56 (8)°, while the phenyl and pyrazole rings subtend a dihedral angle of 19.75 (8)°. The compound is in the enamine-keto form and its structure is stabilized by an intra-molecular N-H⋯O hydrogen bond. In the crystal, mol-ecules are linked via C-H⋯N hydrogen bonds, forming chains along [010]. Between the chains there are π-π inter-actions [inter-centroid distances = 3.3902 (9) and 3.5956 (11) Å], linking the chains to form sheets parallel to (10-1).
authors.affiliation: Department of Chemistry, Hebei Normal University for Nationalities, Chengde, 067000, People's Republic of China.
authors.forename: Heng-Qiang
authors.initials: HQ
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Hebei Normal University for Nationalities, Chengde, 067000, People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Chemistry, Hebei Normal University for Nationalities, Chengde, 067000, People's Republic of China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Chemistry, Hebei Normal University for Nationalities, Chengde, 067000, People's Republic of China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Chen
keywords: 4-acyl­pyrazolone; crystal structure; hydrogen bonding; o-chloro­aniline; pyrazolone
references.citation: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references.pmid: 18156677
references.citation: Acta Crystallogr D Biol Crystallogr. 2009 Feb;65(Pt 2):148-55
references.pmid: 19171970
references.citation: Acta Crystallogr Sect E Struct Rep Online. 2009 Jul 11;65(Pt 8):o1824
references.pmid: 21583526