(2E)-1-(2,4-Dichloro­phen­yl)-3-[3-(4-nitro­phen­yl)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one

Arun M Isloor; Shridhar Malladi; Thomas Gerber; Benjamin van Brecht; Richard Betz

doi:10.1107/S1600536812003960

. 2012 Feb 4;68(Pt 3):o616–o617. doi: 10.1107/S1600536812003960

(2E)-1-(2,4-Dichlorophenyl)-3-[3-(4-nitrophenyl)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one

Arun M Isloor ^a, Shridhar Malladi ^a, Thomas Gerber ^b, Benjamin van Brecht ^b, Richard Betz ^b,^*

PMCID: PMC3295416 PMID: 22412527

Abstract

In the title compound, C₂₄H₁₅Cl₂N₃O₃, the C=C double bond is E configured. The 1-phenyl-1H-pyrazole moiety is roughly planar (r.m.s. deviation of all fitted non-H atoms = 0.0780 Å), but the mean planes of the two components are inclined at an angle of 9.95 (7)°. The mean plane defined by the non-H atoms of the 1H-pyrazole ring encloses angles of 9.95 (7), 24.54 (6) and 43.02 (6)° with the mean planes of the different benzene rings. In the crystal, C—H⋯O contacts are present and result in the formation of a double-layer two-dimensional network lying parallel to (110). The shortest intercentroid distance between two aromatic systems is 3.5455 (7) Å and is apparent between two pyrazole systems. Further π–π interactions are manifest between a pair of 4-nitrophenyl rings [centroid-to-centroid distance = 3.6443 (7) Å] and a pair of 2,4-dichlorophenyl rings [centroid-to-centroid distance = 3.7797 (7) Å].

Related literature

For general background on the pharmaceutical and biological activity of pyrazole compounds, see: Isloor et al. (2009 ▶); Vijesh et al. (2010 ▶); Sharma et al. (2010 ▶); Rostom et al. (2003 ▶); Ghorab et al. (2010 ▶); Amnekar & Bhusari (2010 ▶). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990 ▶); Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₄H₁₅Cl₂N₃O₃
M _r = 464.29
Triclinic,
a = 8.3343 (3) Å
b = 9.3115 (4) Å
c = 13.8699 (6) Å
α = 92.896 (2)°
β = 104.669 (2)°
γ = 96.060 (2)°
V = 1032.12 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.35 mm⁻¹
T = 200 K
0.53 × 0.30 × 0.13 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.931, T _max = 1.000
18344 measured reflections
5116 independent reflections
4588 reflections with I > 2σ(I)
R _int = 0.013

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.086
S = 1.02
5116 reflections
304 parameters
H-atom parameters constrained
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT (Bruker, 2010 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812003960/su2371sup1.cif

e-68-0o616-sup1.cif^{(27.6KB, cif)}

Supplementary material file. DOI: 10.1107/S1600536812003960/su2371Isup2.cdx

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812003960/su2371Isup3.hkl

e-68-0o616-Isup3.hkl^{(250.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812003960/su2371Isup4.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
C5—H5⋯O1ⁱ	0.95	2.39	3.3421 (14)	176
C36—H36⋯O3ⁱⁱ	0.95	2.41	3.3139 (15)	160

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

Acknowledgments

AMI is grateful to the Department of Atomic Energy, Board for Research in Nuclear Sciences, Government of India, for a Young Scientist award.

supplementary crystallographic information

Comment

The pyrazole ring is an important structural motif found in several pharmaceutically active compounds. Because of its easy preparation and rich biological activity, the pyrazole skeleton plays an important role in biologically active compounds such as antibacterial (Isloor et al., 2009; Vijesh et al., 2010), anti-inflammatory (Sharma et al., 2010), analgesic (Rostom et al., 2003), anticancer, radioprotective (Ghorab et al., 2010) and anti-convulsant agents (Amnekar & Bhusari, 2010). Prompted by the diverse activities of pyrazole derivatives, we have synthesized the title compound to study its crystal structure.

In the title compound the C═C double bond in the Michael system adopts (E)-configuration (Fig. 1). The 1-phenyl-1H-pyrazole moiety is essentially planar (r.m.s. deviation of all fitted non-hydrogen atoms = 0.0780 Å). However, the mean planes of the two components are inclined at an angle of 9.95 (7)°.

The N-bonded phenyl ring B (C21–C26), the 4-nitrophenyl ring C (C11–C16), and the 2,4-dichlorophenyl ring D (C31–C36) are inclined to the mean plane of the central heterocyclic five-membered ring A (N1,N2,C4–C6) by 9.95 (7), 24.54 (6) and 43.06 (6) °, respectively. The mean planes defined the phenyl rings (B, C and D) are inclined to one another by angles of B/C = 16.28 (6)°, C/D = 28.40 (6)° and B/D = 40.14 (6)°.

In the crystal, C—H···O contacts whose range falls by more than 0.3 Å below the sum of van der Waals radii of the corresponding atoms are present. They are supported by one of the H atoms of the pyrazole system on the one hand and one of the H atoms on the dichlorophenyl moiety on the other hand. While the former of these contacts applies exclusively to one of the O atoms (O1) on the nitro group as acceptor, the latter ones are apparent in conjunction with the O atom (O3) on the Michael system (Table 1 and Fig. 2). In terms of graph-set analysis (Etter et al., 1990; Bernstein et al., 1995), the descriptor for the C—H···O contacts is C¹₁(11)R²₂(10) on the unitary level.

The shortest intercentroid distance between two aromatic systems is 3.5455 (7) Å involving inversion related pyrazole systems [CgA···CgAⁱ]. Further π–π interactions are manifest between inversion related 4-nitrophenyl rings (CgC···CgCⁱⁱ = 3.6443 (7) Å) and inversion related 2,4-dichlorophenyl rings (CgD···CgDⁱⁱⁱ = 3.7797 (7) Å) [symmetry codes: (i) -x + 2, -y + 1, -z + 1; (ii) -x + 2, -y + 2, -z + 1; (iii) -x + 1, -y, -z].

In total, the molecules are connected into a double layer two-dimensional network lying parallel to plane (110) [Fig. 3].

Experimental

To a cold, stirred mixture of methanol (20 ml) and sodium hydroxide (12.09 mmol) was added 2,4-dichloroacetophenone (4.03 mmol). The reaction mixture was stirred for 10 min. To this was added 3-(4-nitrophenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde (4.03 mmol) followed by tetrahydrofuran (30 ml). The solution was further stirred at 0°C for 2 h and then at room temperature for 5 h. It was then poured into ice cold water. The resulting solution was neutralized with diluted hydrochloric acid. The solid that separated was filtered, washed with water, dried and crystallized from ethanol. Yield: 1.48 g, 79.39% (m.p. 478–480 K).