3-(4-Bromo­phen­yl)-1-phenyl-1H-pyrazole-4-carbaldehyde

R Prasath; P Bhavana; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536811036841

. 2011 Sep 17;67(Pt 10):o2650. doi: 10.1107/S1600536811036841

3-(4-Bromophenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde

R Prasath ^a, P Bhavana ^a,^‡, Seik Weng Ng ^b,^c, Edward R T Tiekink ^b,^*

PMCID: PMC3201369 PMID: 22058775

Abstract

In the title compound, C₁₆H₁₁BrN₂O, the phenyl and chlorobenzene rings are twisted out of the mean plane of the pyrazole ring, forming dihedral angles of 13.70 (10) and 36.48 (10)°, respectively. The carbaldehyde group is also twisted out of the pyrazole plane [the C—C—C—O torsion angle is 7.9 (3)°]. A helical supramolecular chain along the b axis and mediated by C—H⋯O interactions is the most prominent feature of the crystal packing.

Related literature

For background details and biological applications of pyrazoles, see: Kaushik et al. (2010 ▶); Ali et al. (2007 ▶); Krishnamurthy et al. (2004 ▶). For a related structure, see: Asiri et al. (2011 ▶).

Experimental

Crystal data

C₁₆H₁₁BrN₂O
M _r = 327.18
Monoclinic,
a = 17.7233 (4) Å
b = 3.8630 (1) Å
c = 20.4224 (5) Å
β = 110.137 (3)°
V = 1312.75 (6) Å³
Z = 4
Cu Kα radiation
μ = 4.23 mm⁻¹
T = 100 K
0.25 × 0.20 × 0.15 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.418, T _max = 0.569
4619 measured reflections
2593 independent reflections
2542 reflections with I > 2σ(I)
R _int = 0.012

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.069
S = 1.02
2593 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.66 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811036841/hb6403sup1.cif

e-67-o2650-sup1.cif^{(17.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811036841/hb6403Isup2.hkl

e-67-o2650-Isup2.hkl^{(124.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811036841/hb6403Isup3.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
C12—H12⋯O1ⁱ	0.95	2.49	3.435 (2)	171
C16—H16⋯O1ⁱⁱ	0.95	2.46	3.288 (3)	145

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

Acknowledgments

PB acknowledges the Department of Science and Technology (DST), India, for a research grant (SR/FTP/CS-57/2007). The authors also thank the University of Malaya for support of the crystallographic facility.

supplementary crystallographic information

Comment

A broad spectrum of biological activities [anti-bacterial, anti-depressant, anti-convulsive, anti-hypertensive, anti-oxidant anti-viral and anti-tumour] have been noted for pyrazoles and their derivatives (Kaushik et al., 2010; Ali et al., 2007; Krishnamurthy et al., 2004). In continuation of structural studies in this area (Asiri et al., 2011), the title compound, (I), was investigated.

The dihedral angles formed between the central pyrazole ring [r.m.s. deviation = 0.003 Å] and the N– and C-bound benzene rings of 13.70 (10) and 36.48 (10) °, respectively, indicate significant twists in the molecule of (I), Fig. 1. Similarly, the carbaldehyde group is twisted out of the plane of the five-membered ring as seen in the value of the C13—C14—C16—O1 torsion angle of 7.9 (3) °. The relative disposition of the benzene rings preclude close intermolecular association with the imine-N2 atom which, indeed, forms a close intramolecular C2—H···N2 contact, Table 1.

The crystal packing features C—H···O interactions involving a bifurcated carbonyl-O1 atom, Table 1. These result in the formation of a helical supramolecular chain along the b axis, Fig. 2.

Experimental

Phosphoryl chloride (5.6 ml) was added drop wise to cold N,N-dimethylformamide (22.5 ml) under continuous stirring at 273–278 K for about 30 min. 4-Bromoacetophenone phenylhydrazone (5 g, 17 mmol) was added to the above reaction mixture. The resulting mixture was further stirred at 333 K for 6 h. and cooled to room temperature. The crude product was poured into crushed ice which resulted in a white precipitate. The resultant solid was filtered, dried and purified by column chromatography using chloroform. Recrystallization was by slow evaporation of chloroform solution of (I) which yielded colourless prisms. M.pt. 413–415 K. Yield: 56%.