Research Article: 4-[(Z)-(n-Butyl­amino)(phenyl)methyl­idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

Date Published: April 01, 2012

Publisher: International Union of Crystallography

Author(s): Hai-Wen Wang.


The title compound, C21H23N3O, exists in an enamine–keto form with the amino group involved in an intra­molecular N—H⋯O hydrogen bond. The dihedral angle between the phenyl rings is 73.59 (6)°. The five-membered ring is nearly planar, the largest deviation being 0.0004 (7) Å, and makes dihedral angles of 4.81 (6) and 69.81 (5)° wth the phenyl rings. In the crystal, pairs of weak C—H⋯O inter­actions link the mol­ecules into centrosymmetric dimers.

Partial Text

For applications of Schiff bases derived from 4-acyl­pyrazolo­nes, see: Bernardino et al. (2006 ▶); Zhang et al. (2008 ▶). For related structures, see: Zhang et al. (2007 ▶); Chi et al. (2010 ▶); Zhen & Han (2005 ▶); Wang (2010 ▶).