(E)-1-(2,4-Dichloro­phen­yl)-3-(1,3-diphenyl-1H-pyrazol-4-yl)prop-2-en-1-one

Hoong-Kun Fun; Ching Kheng Quah; Shridhar Malladi; Arun M Isloor; Kammasandra N Shivananda

doi:10.1107/S1600536811044382

. 2011 Oct 29;67(Pt 11):o3102–o3103. doi: 10.1107/S1600536811044382

(E)-1-(2,4-Dichlorophenyl)-3-(1,3-diphenyl-1H-pyrazol-4-yl)prop-2-en-1-one

Hoong-Kun Fun ^a,^*,^‡, Ching Kheng Quah ^a,^§, Shridhar Malladi ^b, Arun M Isloor ^b, Kammasandra N Shivananda ^c

PMCID: PMC3247488 PMID: 22220106

Abstract

In the title molecule, C₂₄H₁₆Cl₂N₂O, the dihedral angles between the pyrazole ring and its N- and C-bonded phenyl rings are 7.06 (10) and 53.15 (10)°, respectively. The dihedral angle between the two pendant rings is 52.32 (10)°. The molecule exists in a trans conformation with respect to the acyclic C=C bond. In the crystal, inversion dimers occur in which each molecule is linked to the other by two C—H⋯O hydrogen bonds to the same acceptor O atom. There are also short Cl⋯Cl contacts [3.3492 (9) Å] and C—H⋯π interactions.

Related literature

For general background to and the biological activity of pyrazoles, see: Patel et al. (2004 ▶); Isloor et al. (2009 ▶); Vijesh et al. (2010 ▶); Sharma et al. (2010 ▶); Rostom et al. (2003 ▶); Ghorab et al. (2010 ▶); Amnekar & Bhusari (2010 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For standard bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₂₄H₁₆Cl₂N₂O
M _r = 419.29
Triclinic,
a = 9.6185 (8) Å
b = 10.6596 (9) Å
c = 11.8537 (10) Å
α = 67.377 (2)°
β = 75.777 (1)°
γ = 69.934 (2)°
V = 1044.64 (15) Å³
Z = 2
Mo Kα radiation
μ = 0.33 mm⁻¹
T = 296 K
0.31 × 0.21 × 0.08 mm

Data collection

Bruker SMART APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.904, T _max = 0.973
22059 measured reflections
6053 independent reflections
3980 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.134
S = 1.04
6053 reflections
262 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811044382/hb6456sup1.cif

e-67-o3102-sup1.cif^{(21.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811044382/hb6456Isup2.hkl

e-67-o3102-Isup2.hkl^{(296.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811044382/hb6456Isup3.cml

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

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

Cg1 and Cg2 are the centroids of the C19–C24 and C13–C18 benzene rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11A⋯O1ⁱ	0.93	2.30	3.230 (2)	174
C20—H20A⋯O1ⁱ	0.93	2.59	3.509 (3)	168
C2—H2A⋯Cg1ⁱⁱ	0.93	2.75	3.585 (2)	149
C23—H23A⋯Cg2ⁱⁱⁱ	0.93	2.90	3.655 (2)	140

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

Acknowledgments

HKF and CKQ thank Universiti Sains Malaysia for the Research University Grant (No. 1001/PFIZIK/811160). AMI is thankful to the Department of Atomic Energy, Board for Research in Nuclear Sciences, Government of India, for the Young scientist award.

supplementary crystallographic information

Comment

Pyrazoles are novel class of heterocyclic compounds possessing wide variety of application in the agrochemical and pharmaceutical industries (Patel et al., 2004). Derivatives of pyrazoles are found to show good 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 activity (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 molecule (Fig. 1), the phenyl (C1-C6) ring and the two benzene (C13-C18 and C19-C24) rings form dihedral angles of 64.29 (9), 53.15 (10) and 7.06 (10)°, respectively, with the pyrazole ring (N1/N2/C10-C12). The phenyl ring also forms dihedral angles of 65.06 (10) and 67.80 (10)° with the two benzene rings (C13-C18 and C19-C24), respectively. The benzene rings form a dihedral angle of 52.32 (10)°. The title molecule exists in trans conformation with respect to the acyclic C8═C9 bond [bond length = 1.330 (2) Å]. Bond lengths (Allen et al., 1987) and angles are within normal ranges. There is a short Cl2···Cl2 contact (symmetry code : -x, 1-y, 1-z) with distance = 3.3492 (9) Å which is shorter than the sum of van der Waals radii of the Cl atoms.

In the crystal (Fig. 2), molecules are linked into inversion dimers by intermolecular bifurcated C11–H11A···O1 and C20–H20A···O1 acceptor bonds (Table 1), generating six-membered R¹₂(6) ring motifs (Bernstein et al., 1995). The crystal structure is further consolidated by C2–H2A···Cg1 and C23–H23A···Cg2 (Table 1) interactions, where Cg1 and Cg2 are the centroids of C19-C24 and C13-C18 benzene rings, respectively.

Experimental

To a cold, stirred mixture of methanol (20 ml) and sodium hydroxide (12.09 mmol), 2,4-dichloroacetophenone (4.03 mmol) was added. The reaction mixture was stirred for 10 min. 1,3-Diphenyl-1H-pyrazole-4-carbaldehyde (4.03 mmol) was added to this solution followed by tetrahydrofuran (30 ml). The solution was further stirred for 2 h at 273 K and then at room temperature for 5 h. It was then poured into ice cold water. The resulting solution was neutralized with Dil. HCl. The solid that separated was filtered, washed with water, dried and crystallized from ethanol to yield colourless blocks of (I). Yield: 1.28 g, 76.19 %. M.p.: 406-408 K.