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

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

doi:10.1107/S1600536811044424

. 2011 Oct 29;67(Pt 11):o3104. doi: 10.1107/S1600536811044424

(E)-3-[3-(4-Bromophenyl)-1-phenyl-1H-pyrazol-4-yl]-1-(2,4-dichlorophenyl)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: PMC3247489 PMID: 22220107

Abstract

In the title molecule, C₂₄H₁₅BrCl₂N₂O, the dihedral angles betwen the pyrazole ring and its N-bonded phenyl (A) and C-bonded bromobenzene (B) rings are 10.34 (16) and 40.95 (15)°, respectively. The dihedral angle between rings A and B is 56.89 (17)°. The title molecule exists in a trans conformation with respect to the acyclic C=C bond. In the crystal, molecules are linked into inversion dimers by pairs of C—H⋯O hydrogen bonds, generating R ² ₂(14) loops. The crystal structure is further consolidated by C—H⋯π interactions.

Related literature

For a related structure and background references to pyrazoles, see: Fun et al. (2011 ▶). For standard bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₄H₁₅BrCl₂N₂O
M _r = 498.19
Monoclinic,
a = 11.4203 (14) Å
b = 9.9357 (13) Å
c = 19.656 (3) Å
β = 94.653 (3)°
V = 2222.9 (5) Å³
Z = 4
Mo Kα radiation
μ = 2.11 mm⁻¹
T = 296 K
0.38 × 0.21 × 0.11 mm

Data collection

Bruker SMART APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.504, T _max = 0.803
23842 measured reflections
6480 independent reflections
2743 reflections with I > 2σ(I)
R _int = 0.056

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.140
S = 0.98
6480 reflections
271 parameters
H-atom parameters constrained
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.52 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/S1600536811044424/hb6462sup1.cif

e-67-o3104-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811044424/hb6462Isup2.hkl

e-67-o3104-Isup2.hkl^{(317.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811044424/hb6462Isup3.cml

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

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

Cg1 is the centroid of C1–C6 phenyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11A⋯O1ⁱ	0.93	2.41	3.329 (4)	170
C15—H15A⋯Cg1ⁱⁱ	0.93	2.82	3.666 (3)	152

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

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

As part of our ongoing studies of pyrazole derivatives with potential biological activities (Fun et al., 2011), we have synthesized the title compound, (I), to study its crystal structure.

In the title molecule (Fig. 1), the benzene (C19-C24) ring and the two phenyl (C1-C6 and C13-C18) rings form dihedral angles of 10.34 (16), 50.23 (16) and 40.95 (15)°, respectively, with the pyrazole ring (N1/N2/C10-C12). The benzene ring also forms dihedral angles of 56.89 (17) and 38.81 (16)° with dichloro-bound phenyl (C1-C6) and bromo-bound phenyl (C13-C18) rings, respectively. The phenyl rings form a dihedral angle of 89.57 (17)°. The title molecule exists in trans configuration with respect to the acyclic C8═C9 bond [bond length = 1.336 (4) Å]. Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to a related structure (Fun et al., 2011).

In the crystal (Fig. 2), molecules are linked into inversion dimers by pairs of intermolecular C11–H11A···O1 hydrogen bonds (Table 1), generating fourteen-membered D²₂(14) ring motifs (Bernstein et al., 1995). The crystal structure is further consolidated by C15–H15A···Cg1 (Table 1) interactions, where Cg1 is the centroid of C1-C6 phenyl ring.

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. 3-(4-Bromophenyl)-1-phenyl-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 out was filtered, washed with water, dried and crystallized from ethanol to yield colourless blocks. Yield: 1.6 g, 80 %. M.p.: 457-458 K.