1-Phenyl-1H-pyrazole-4-carbaldehyde

Abdullah M Asiri; Hassan M Faidallah; Tariq R Sobahi; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812010896

. 2012 Mar 17;68(Pt 4):o1088. doi: 10.1107/S1600536812010896

1-Phenyl-1H-pyrazole-4-carbaldehyde

Abdullah M Asiri ^a,^b,^‡, Hassan M Faidallah ^a, Tariq R Sobahi ^a, Seik Weng Ng ^c,^a, Edward R T Tiekink ^c,^*

PMCID: PMC3344042 PMID: 22589951

Abstract

In the title molecule, C₁₀H₈N₂O, the five- and six-membered rings form a dihedral angle of 10.14 (9)°. The aldehyde group is almost coplanar with the pyrazole ring to which it is connected [O—C—C—C torsion angle = −179.35 (17)°]. In the crystal, inversion dimers are linked by four C—H⋯O interactions as the carbonyl O atom accepts two such bonds. The dimeric aggregates are linked into supramolecular layers in the ac plane by C—H⋯π and π–π [ring centroid(pyrrole)⋯ring centroid(phenyl) = 3.8058 (10) Å] interactions.

Related literature

For the anti-bacterial properties of pyrazole derivatives, see: Kane et al. (2003 ▶). For related structures, see: Asiri, Al-Youbi, et al. (2012 ▶); Asiri, Faidallah et al. (2012 ▶). For the synthesis, see: Vera-DiVaio et al. (2009 ▶).

Experimental

Crystal data

C₁₀H₈N₂O
M _r = 172.18
Monoclinic,
a = 11.1657 (10) Å
b = 5.0858 (4) Å
c = 15.3034 (11) Å
β = 111.130 (9)°
V = 810.60 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.30 × 0.30 × 0.15 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.972, T _max = 0.986
3485 measured reflections
1814 independent reflections
1359 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.136
S = 0.99
1814 reflections
151 parameters
All H-atom parameters refined
Δρ_max = 0.28 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); 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/S1600536812010896/bt5843sup1.cif

e-68-o1088-sup1.cif^{(14.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812010896/bt5843Isup2.hkl

e-68-o1088-Isup2.hkl^{(89.3KB, hkl)}

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

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

Cg1 is the centroid of the C5–C10 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯O1ⁱ	0.960 (19)	2.432 (19)	3.379 (2)	168.6 (13)
C10—H10⋯O1ⁱ	0.978 (19)	2.335 (19)	3.303 (2)	170.8 (16)
C8—H8⋯Cg1ⁱⁱ	0.978 (18)	2.947 (18)	3.761 (2)	141.4 (14)

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

Acknowledgments

The authors are thankful to the Center of Excellence for Advanced Materials Research and the Chemistry Department at King Abdulaziz University for providing the research facilities. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

In continuation of structural studies of pyrazole derivatives (Asiri, Al-Youbi, et al., 2012; Asiri, Faidallah et al., 2012), of interest, for example, owing to their anti-bacterial activity (Kane et al., 2003), the title compound, 1-phenyl-1H-pyrazole-4-carbaldehyde (I), was investigated crystallographically.

In (I), Fig. 1, the dihedral angle between the five- and six-membered rings is 10.14 (9) °, indicating a slight twist in the molecule. The aldehyde group is co-planar with the pyrazole ring to which it is connected as seen in the value of the O1—C1—C2—C3 torsion angle of -179.35 (17)°.

Inversion related molecules are connected into dimers via C—H···O interactions involving a bifurcated carbonyl-O atom, Table 1. Dimers are linked into supramolecular layers in the ac plane via C—H···π and π—π interactions occurring between the five- and six-membered rings [ring centroid···ring centroid distance = 3.8058 (10) Å, angle of inclination = 10.14 (9)° for symmetry operation: x, -1 + y, z], Fig. 2 and Table 1. Layers stack with no specific intermolecular interactions between them, Fig. 3.

Experimental

N,N-Dimethylformamide (25.6 ml, 0.33 mmol) was stirred in around flask within an ice-bath and POCl₃ (21.6 ml, 0.23 mmol) was added drop-wise. Then N-phenylpyrazole was added (4.4 ml, 0.033 mmol) to this cold mixture. The reaction was allowed to warm to room temperature and then heated at reflux for 6 h. The temperature was kept at 368–373 K. When the reaction was completed, the contents were poured onto crushed ice and made weakly alkaline with a saturated solution of sodium carbonate. The solid was filtered off, washed with water and recrystallized from ethanol. Yield: 65%. M.pt. 358–359 K. (lit. 358 K; Vera-DiVaio et al., 2009).