1-(2,4-Dichloro­phen­yl)-5-(2-nitro­anilino)-1H-pyrazole-4-carbonitrile

Ju Liu; Zhi-Qiang Cai; Yang Wang; Chun-Yan Li; Li-Feng Xu

doi:10.1107/S1600536812011506

. 2012 Mar 24;68(Pt 4):o1142. doi: 10.1107/S1600536812011506

1-(2,4-Dichlorophenyl)-5-(2-nitroanilino)-1H-pyrazole-4-carbonitrile

Ju Liu ^a, Zhi-Qiang Cai ^b,^*, Yang Wang ^a, Chun-Yan Li ^c, Li-Feng Xu ^a

PMCID: PMC3344087 PMID: 22606090

Abstract

In the title compound, C₁₆H₉Cl₂N₅O₂, the folded molecular conformation is characterized by a dihedral angle between the two benzene rings of 74.03 (5)°. An intramolecular N—H⋯O hydrogen bond is observed between the H atom of the amide group and a nitro-group O atom. Intermolecular C—H⋯O and N—H⋯N hydrogen bonds feature in the crystal packing.

Related literature

For general background to N-1-diaryl-1H-pyrazol-5-amine derivatives as synthetic intermediates in the preparation of medicinal compounds and the synthesis of the title compound, see: Markwalder et al. (2004 ▶); Mehdi et al. (2010 ▶). For the pharmacological activity of the 5-aminopyrazole nucleus, see: Nils et al. (2010 ▶); Aymn et al. (2005 ▶).

Experimental

Crystal data

C₁₆H₉Cl₂N₅O₂
M _r = 374.18
Orthorhombic,
a = 13.878 (3) Å
b = 13.475 (3) Å
c = 17.421 (4) Å
V = 3257.7 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.42 mm⁻¹
T = 293 K
0.20 × 0.18 × 0.12 mm

Data collection

Rigaku Saturn724 CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005) ▶ T _min = 0.921, T _max = 0.951
31011 measured reflections
3888 independent reflections
2738 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.142
S = 1.04
3888 reflections
231 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalClear (Rigaku/MSC, 2005) ▶; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812011506/kp2396sup1.cif

e-68-o1142-sup1.cif^{(19.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812011506/kp2396Isup2.hkl

e-68-o1142-Isup2.hkl^{(190.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812011506/kp2396Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9⋯O2ⁱ	0.93	2.51	3.050 (3)	117
C5—H5⋯O1ⁱⁱ	0.93	2.58	3.374 (3)	143
N4—H4⋯N3ⁱⁱⁱ	0.82 (3)	2.62 (3)	3.201 (3)	129 (2)
N4—H4⋯O1	0.82 (3)	2.02 (3)	2.608 (2)	128 (2)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

The authors thank the State Key Laboratory of Elemento-organic Chemistry, Nankai University, for the X-ray data collection.

supplementary crystallographic information

Comment

N-1-Diaryl-1H-pyrazol-5-amine derivatives possess therapeutic value. They are synthetic intermediates in the preparation of medicinal compounds (Markwalder et al., 2004; Mehdi et al., 2010). 5-Aminopyrazole nucleus is associated with several pharmacological activities such as selective adenosine A1 receptor antagonists (Nils et al., 2010) and antimicrobial activity (Aymn et al., 2005). In view of this biological importance a part of our ongoing studies of pyrazole derivatives includes the crystal structure determination of the title compound. The folded molecular conformation is characterised by the dihedral angle between the two benzene rings of 74.03 (5) ° (Fig. 1). Intramolecular N—H···O hydrogen bond between the hydrogen of the amide group and the nitro group O atom is observed. The crystal packing is stabilised by intermolecular C—H···O and N—H···N hydrogen bonds (Table 1).

Experimental

To a mixture of 5-amino-1-(2,4-dichlorophenyl)-1H-pyrazole-4-carbonitrile (3.0 g, 11.85 mmol) and o-nitrochlorobenzene (3.74 g, 23.74 mmol) in dimethyl sulfoxide (10 mL) lithium hydroxide monohydrate (0.74 g, 17.87 mmol) was added. The solution was heated at 343 K for 4.5 h. After cooling to 293 K, 50 mL of water was added to the reaction mixture. The resulting precipitate was collected by filtration, washed with ethanol to yield the title compound as a brown yellow solid (3.28 g, 73.95%). Crystals suitable for X-ray analysis were obtained from ethanol:acetone (1:1) solution by slow evaporation.