2-Chloro-N-[1-(4-chloro­phen­yl)-3-cyano-1H-pyrazol-5-yl]acetamide

Hai-ping Mu; Yang Yang; Qiang-hua Jiang; Xiao-dong Fu; Rong Wan

doi:10.1107/S1600536812043966

. 2012 Oct 31;68(Pt 11):o3249. doi: 10.1107/S1600536812043966

2-Chloro-N-[1-(4-chlorophenyl)-3-cyano-1H-pyrazol-5-yl]acetamide

Hai-ping Mu ^a, Yang Yang ^a, Qiang-hua Jiang ^a, Xiao-dong Fu ^a, Rong Wan ^a,^*

PMCID: PMC3515326 PMID: 23284546

Abstract

The title compound, C₁₂H₈Cl₂N₄O, was synthesized by the reaction of 5-amino-1-(4-chlorophenyl)-1H-pyrazole-3-carbonitrile and 2-chloroacetyl chloride. The dihedral angle between the pyrazole and benzene rings is 30.7 (3)°. In the crystal structure, strong N—H⋯O hydrogen bonds link the molecules into chains along [001]. C—H⋯N hydrogen bonds are also present.

Related literature

The title compound is important in the synthesis of derivatives of the insecticide Fipronil {systematic name: (RS)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-(trifluoromethylsulfinyl)-1H-pyrazole-3-carbonitrile}. For the biological activity of N-pyrazole derivatives, see: Zhao et al. (2010 ▶); Liu et al. (2010 ▶). For bond-length data, see: Allen et al. (1987 ▶). For the structure of 2-chloro-N-(3-cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-1H-pyrazol-5-yl)acetamide, see: Zhang et al. (2012 ▶).

Experimental

Crystal data

C₁₂H₈Cl₂N₄O
M _r = 295.12
Orthorhombic,
a = 18.493 (4) Å
b = 13.815 (3) Å
c = 5.060 (1) Å
V = 1292.7 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.50 mm⁻¹
T = 293 K
0.30 × 0.20 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.865, T _max = 0.952
2646 measured reflections
2606 independent reflections
2255 reflections with I > 2σ(I)
R _int = 0.024
3 standard reflections every 200 reflections intensity decay: 1%

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.099
S = 1.01
2606 reflections
173 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.24 e Å⁻³
Absolute structure: Flack (1983 ▶), 1271 Friedel pairs
Flack parameter: 0.09 (9)

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); 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: SHELXS97.

Supplementary Material

Click here for additional data file.^{(17.4KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812043966/rn2106sup1.cif

e-68-o3249-sup1.cif^{(17.4KB, cif)}

Click here for additional data file.^{(128KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812043966/rn2106Isup2.hkl

e-68-o3249-Isup2.hkl^{(128KB, hkl)}

Click here for additional data file.^{(4.6KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812043966/rn2106Isup3.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
N3—H3A⋯Oⁱ	0.86	2.16	2.858 (3)	137
C12—H12C⋯N2ⁱⁱ	0.97	2.52	3.445 (3)	160

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

Acknowledgments

The authors thank the Science and Technology Project of Jiangsu Province (No. BE2011352) for financial support and acknowledge the help of members of the laboratory.

supplementary crystallographic information

Comment

N-Pyrazole derivatives are of great interest because of their diverse biological activities such as insecticidal (Zhao et al., 2010) and antifungal activities (Liu et al., 2010). The title compound is an important intermediate in the synthesis of N-aromatic pyrazole derivatives. The molecular structure of (I) is shown in Fig.1. In this structure, bond length and angles are within the normal range (Allen et al., 1987) and the mean deviation from the plane(N1/N2/C9/C8/C7) is 0.0045 Å. The dihedral angle between the pyrazole and phenyl ring in compound (I) is 30.7 (3)°, which is smaller than the angle in the structure of 2-chloro-N- (3-cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-1H-pyrazol-5-yl) acetamide (Zhang et al., 2012), which is 71.5 (3)°. While bond lengths of the two compounds are similar, the difference in the dihedral angle probably results from greater steric hindrance in the (trifluoromethyl)phenyl derivative. In the crystal structure, strong N—H···O hydrogen bonds link the molecules into infinite one-dimensional chains along the [001] direction. Intermolecular C—H···N and N—H···O hydrogen bonds (Table 1) may help to establish the molecular conformation of (I). (Fig. 2)

Experimental

To a stirred solution of 5-amino-1-(4-chlorophenyl)-1H-pyrazole-3-carbonitrile (5 mmol) in THF (20 ml) was added 2-chloroacetyl chloride (5 mmol) dropwise at 0–5°C. During the addition, the solution is cooled in an ice-salt bath. After the cooling bath had been removed, the reaction mixture was allowed to stand for 2 h at room temperature. The crude product (I) precipitated and was filtered. Pure compound (I) was obtained by crystallization from ethanol. Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an acetone solution.