title: Crystal structure of (Z)-4-[1-(4-acetyl-anilino)ethyl-idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.
abstract: In the solid state, the title compound, C20H19N3O2, adopts the keto-amine tautomeric form, with the H atom attached to the N atom, which participates in an intra-molecular N-H⋯O hydrogen bond with an S(6) ring motif. The dihedral angles between the pyrazole ring and the phenyl and benzene rings are 3.69 (10) and 46.47 (9)°, respectively. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, generating C(16) chains propagating in [301]. Weak aromatic π-π stacking inter-actions [centroid-centroid distances = 3.6123 (10) and 3.6665 (10) Å] link the chains into a three-dimensional network.
authors.affiliation: Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516, Egypt.
authors.forename: Refaat M
authors.initials: RM
authors.lastname: Mahfouz
authors.affiliation: Department of Physics, Ondokuz Mayıs University, TR-55139 Samsun, Turkey.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Demircioğlu
authors.affiliation: Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516, Egypt.
authors.forename: Mohamed S
authors.initials: MS
authors.lastname: Abbady
authors.affiliation: Department of Physics, Ondokuz Mayıs University, TR-55139 Samsun, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Büyükgüngör
keywords: Schiff bases; crystal structure; hydrogen bonding; keto–amine tautomeric form; pyrazolone derivatives; π–π stacking inter­actions