5-Amino-3-anilino-1H-pyrazole-4-carbonitrile

In the title compound, C10H9N5, the phenyl ring is twisted with respect to the pyrazole ring, forming a dihedral angle of 24.00 (6)°. In the crystal, molecules are linked by N—H⋯N hydrogen bonds into chains running parallel to [010] containing alternating R 2 2(6) and R 2 2(12) rings. Further interactions are found in the crystal, viz. N—H⋯π(phenyl) interactions and weak face-to-face π–π stacking interactions [centroid–centroid distance = 3.8890 (6) Å] between the centroids of the pyrazole and phenyl rings are observed.

In the title compound, C 10 H 9 N 5 , the phenyl ring is twisted with respect to the pyrazole ring, forming a dihedral angle of 24.00 (6) . In the crystal, molecules are linked by N-HÁ Á ÁN hydrogen bonds into chains running parallel to [010] containing alternating R 2 2 (6) and R 2 2 (12) rings. Further interactions are found in the crystal, viz. N-HÁ Á Á(phenyl) interactions and weak face-to-facestacking interactions [centroid-centroid distance = 3.8890 (6) Å ] between the centroids of the pyrazole and phenyl rings are observed.

D-HÁ
Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX The interest in pyrazole compounds stems from their pharmaceutical and agricultural applications such as drugs, dyes and anaesthetics (Grimmett, 1970;Sheikh et al., 2009;Kaushik et al., 2010;Krishnamurthy et al., 2004). In addition, such pyrazoles and related compounds are common molecules used in coordination or organometallic chemistry as bridging ligands, utilizing the ring positions of the two N atoms (Lynch & McClenaghan, 2005). We report herein the crystal structure of the title compound which was synthesized by our team as a precursor having two functional substituents (amino and nitrile groups) for the purposes of synthesis of multi-fused pyrazolo-heterocyclic compounds such as nitrogen bridgehead derivatives having potential biological activities (Soliman et al., 2010).
In the molecule of the title compound, (Fig. 1), the phenyl and 1H-pyrazole ring makes a dihedral angle of 24.00 (6)° with each other.

Experimental
The title compound was prepared according to the literature procedure (Soliman et al., 2010). Crystals were obtained from an ethanol solution of (I) by slow evaporation (M.pt: 481 K).

Refinement
The hydrogen atoms bound to nitrogen were located from a difference Fourier map and were refined with a distance restraint of N-H = 0.86 (2) Å; their U iso values were refined freely. The hydrogen atoms bound to carbon were positioned geometrically and refined using a riding model with C-H = 0.93 Å, and with U iso = 1.2U eq (C). The absolute structure could not be determined reliably; Friedel pairs were not merged.

Figure 2
View of chains of the dimers formed by pairs of N-H···N hydrogen bonds, with the R 2 2 (12) and R 2 2 (6) motifs connected into a supramolecular chain. H atoms not involved in hydrogen bonds have been omitted for clarity.

5-Amino-3-anilino-1H-pyrazole-4-carbonitrile
Crystal data C 10 H 9 N 5 M r = 199.22 Orthorhombic, P2 1 2 1 2 1 Hall symbol: P 2ac 2ab a = 6.3441 (1) Å b = 11.1354 (2) Å c = 13.7754 (3)  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.32 e Å −3 Δρ min = −0.20 e Å −3 Absolute structure: nd Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. Refinement on F 2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses 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 observed criterion of F 2 > σ(F 2 ) is used only for calculating -R-factor-obs 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.