Date Published: April 01, 2012
Publisher: International Union of Crystallography
Author(s): Thomas C. Baddeley, Solange M. S. V. Wardell, Edward R. T. Tiekink, James L. Wardell.
In the title pyrazolone derivative, C15H12N2O, the five-membered ring is approximately planar (r.m.s. deviation = 0.018 Å), and the N- and C-bound benzene rings are inclined to this plane [dihedral angles = 21.45 (10) and 6.96 (10)°, respectively] and form a dihedral angle of 20.42 (10)° with each other. Supramolecular layers are formed in the crystal structure via C—H⋯O and C—H⋯N interactions, and these are assembled into double layers by C—H⋯π and π–π interactions between the pyrazole and C-bound benzene rings [ring centroid–centroid distance = 3.6476 (12) Å]. The double layers stack along the a axis being connected by π–π interactions between the N- and C-bound benzene rings [ring centroid–centroid distance = 3.7718 (12) Å].
For the therapeutic importance of pyrazoles, see: Sil et al. (2005 ▶); Haddad et al. (2004 ▶). For their diverse pharmacological activities, see: Bekhit et al. (2012 ▶); Castagnolo et al. (2008 ▶); Ramajayam et al. (2010 ▶). For background to the synthesis, see: Nef (1891 ▶); Katritzky et al. (1997 ▶); Wardell et al. (2007 ▶); de Lima et al. (2010 ▶). For evaluation of tautomeric forms using NMR MO calculations and crystallography, see: Feeney et al. (1970 ▶); Hawkes et al. (1977 ▶); Freyer et al. (1983 ▶); Dardonville et al. (1998 ▶); Kleinpeter & Koch (2001 ▶); Bechtel et al. (1973a ▶,b ▶); Chmutova et al. (2001 ▶); Wardell et al. (2007 ▶); Gallardo et al. (2009 ▶); Ding & Zhao (2010 ▶). For a previous synthesis, see: Kimata et al. (2007 ▶). For a recently reported structure, see: Wardell et al. (2012 ▶).