Crystal structure of 1-(2,4-dinitrophenyl)-3,5-diphenyl-1H-pyrazole

In the title molecule, C21H14N4O4, the phenyl rings make dihedral angles of 39.61 (8) and 9.4 (1)°, respectively, with the central pyrazole ring. The dihedral angle between the pyrazole and dinitrophenyl rings is 46.95 (5)°. In the crystal, molecules pack in helical stacks parallel to the a axis aided by weak C—H⋯O interactions.


S1. Comment
The heterocyclic pyrazole scaffold compounds demonstrate a remarkable wide range of pharmacological activities such as anti-inflammatory (Szabó et al., 2008), anti-bacterial, antifungal (Tanitame et al., 2005, hypoglycemic (Cottineau et al., 2002;Mokhtar & El-Khawass, 1988), inhibition of cyclooxigenase-2 (Rida et al., 2009) andanti-angiogenic (Abadi et al., 2003). Different pyrazole derivatives have also shown anti-proliferative and antitumor activities (Sharma et al., 2014). More recently, the pyrazole ring system represents an advantageous choice for the synthesis of pharmaceutical compounds with different activities and good safety profiles (Mykhailiuk, 2015). In this context and following our ongoing study of the synthesis of bio-active heterocyclic molecules we report in this study the synthesis and crystal structure of the title compound.

S3. Refinement
H-atoms attached to carbon were placed in calculated positions (C-H = 0.95 Å). All were included as riding contributions with isotropic displacement parameters 1.2 times those of the attached atoms. The absolute structure could not be determined.

Figure 1
The title molecule with the labeling scheme and 50% probability ellipsoids.

Figure 2
Packing viewed down the a axis with weak C-H···O interactions depicted as dotted lines.

Figure 3
Packing viewed down the b axis with weak C-H···O interactions depicted as dotted lines.

Special details
Experimental. The diffraction data were collected in three sets of 363 frames (0.5° width in ω) at φ = 0, 120 and 240°. A scan time of 40 sec/frame was used. Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger. H-atoms attached to carbon were placed in calculated positions (C-H = 0.95 Å). All were included as riding contributions with isotropic displacement parameters 1.2 times those of the attached atoms.