3-(3-Chloro-2-hy­droxy­phen­yl)-1-phenyl-1H-pyrazole-4-carbaldehyde

Pradeep Lokhande; Kamal Hasanzadeh; Hamid Khaledi; Hapipah Mohd Ali

doi:10.1107/S1600536811038025

. 2011 Sep 30;67(Pt 10):o2736. doi: 10.1107/S1600536811038025

3-(3-Chloro-2-hydroxyphenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde

Pradeep Lokhande ^a, Kamal Hasanzadeh ^a, Hamid Khaledi ^b,^*, Hapipah Mohd Ali ^b

PMCID: PMC3201353 PMID: 22058800

Abstract

In the title compound, C₁₆H₁₁ClN₂O₂, the pyrazole ring makes dihedral angles of 11.88 (13) and 22.33 (13)° with the 3-chloro-2-hydroxybenzene group and phenyl rings, respectively. The phenolic hydroxy group forms an intramolecular O—H⋯N hydrogen bond with the imine N atom of the pyrazole unit. The formyl group is virtually coplanar with the pyrazole ring [dihedral angle = 4.5 (19)°] and acts as an acceptor in an intramolecular C—H⋯O hydrogen bond closing seven-membered ring. In the crystal, adjacent molecules are linked through C—H⋯O hydrogen bonds into infinite chains along the b axis.

Related literature

For structures of similar compounds, see: Jeyakanthan et al. (2001 ▶); Shanmuga Sundara Raj et al. (1999 ▶).

Experimental

Crystal data

C₁₆H₁₁ClN₂O₂
M _r = 298.72
Orthorhombic,
a = 3.8142 (1) Å
b = 15.9367 (3) Å
c = 21.4121 (5) Å
V = 1301.55 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.30 mm⁻¹
T = 100 K
0.11 × 0.06 × 0.04 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.968, T _max = 0.988
11133 measured reflections
2563 independent reflections
2195 reflections with I > 2σ(I)
R _int = 0.061

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.075
S = 1.04
2563 reflections
223 parameters
Only H-atom coordinates refined
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.23 e Å⁻³
Absolute structure: Flack (1983 ▶), 1005 Friedel pairs
Flack parameter: −0.03 (7)

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: ’SHELXL97 and publCIF (Westrip, 2010 ▶)’.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811038025/gk2410sup1.cif

e-67-o2736-sup1.cif^{(20.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811038025/gk2410Isup2.hkl

e-67-o2736-Isup2.hkl^{(125.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811038025/gk2410Isup3.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
O1—H1⋯N2	0.79 (3)	1.89 (3)	2.585 (2)	147 (3)
C5—H5⋯O2	0.95 (2)	2.18 (2)	3.024 (3)	148 (2)
C10—H10⋯O1ⁱ	1.00 (3)	2.58 (3)	3.568 (3)	171 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

Financial support from the University of Malaya is highly appreciated (PPP grant PS359/2009 C).

supplementary crystallographic information

Comment

The title compound was synthesized through the action of Vilsmeier–Haack reagent (DMF/POCl₃) on 3-chloro-2-hydroxyacetophenone phenylhydrazone. The compound contains three aromatic rings, the dihedral angles between them being 11.88 (13)° (pyrazole and phenol), 22.33 (13)° (pyrazole and phenyl) and 31.29 (12)° (phenyl and phenol). The phenol hydroxyl is hydrogen bonded to the pyrazole nitrogen, N2, and the formyl oxygen atom is directed towards the phenol ring to make an intramolecular C—H···O hydrogen bond with C5—H5. In contrary, in the crystal structures of the related compounds (Jeyakanthan et al., 2001; Shanmuga Sundara Raj et al., 1999) the formyl oxygen atoms are directed away from the phenol rings, being involved in intermolecular C—H···O hydrogen bonding. The crystal packing of the present compound exhibits infinite chains along the b axis formed by intermoleculoar C—H···O hydrogen bonds (Table 1).

Experimental

A mixture of equivalent amounts (24 mmol) of 3-chloro-2-hydroxyacetophenone and phenyl hydrazine in methanol (40 ml) was refluxed for 2 h. The reaction mixture was then cooled to room temperature whereupon the condensation product, 3-chloro-2-hydroxy acetophenone phenylhydrazone, was seperated out with 92% yield. The hydrazone (2.6 g, 0.01 mol) was dissolved in DMF (15 ml) and then POCl₃ (0.03 mol) was added dropwise at 0 ^oC. After the addition was complete, the reaction mixture was warmed to 60–70 ^oC and stirred for 2.5 h. The mixture was then poured onto crushed ice and neutralized by aqueous NaOH solution (10%). The precipitate was filtered, strongly washed with water and recrystallized from ethanol, yielding 85% of the pyrazole product (m.p. = 422-423 K). The needle shaped crystals of the compound were grown in a DMF solution at room temperature.