3,5-Bis(4-fluoro­phen­yl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde

Zeliha Baktır; Mehmet Akkurt; S Samshuddin; B Narayana; H S Yathirajan

doi:10.1107/S160053681101587X

. 2011 May 7;67(Pt 6):o1292–o1293. doi: 10.1107/S160053681101587X

3,5-Bis(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde

Zeliha Baktır ^a, Mehmet Akkurt ^a,^*, S Samshuddin ^b, B Narayana ^b, H S Yathirajan ^c

PMCID: PMC3120319 PMID: 21754699

Abstract

In the title molecule, C₁₆H₁₂F₂N₂O, the pyrazole ring adopts a slight envelope conformation with the methylene C atom deviating by 0.114 (3) Å from the mean plane of the other four atoms [maximum deviation = 0.021 (3) Å]. The dihedral angles between the four essentially planar atoms of the pyrazole ring and the fluoro-substituted benzene rings are 2.6 (2) and 82.2 (2)°. The dihedral angle between the two benzene rings is 83.7 (2)°. The crystal packing is stabilized by weak intermolecular C—H⋯O hydrogen bonds.

Related literature

For the biological activity of pyrazolines, see: Hes et al. (1978 ▶); Manna et al. (2005 ▶); Amir et al. (2008 ▶); Regaila et al. (1979 ▶); Sarojini et al. (2010 ▶). For their importance in organic synthesis, see: Bhaskarreddy et al. (1997 ▶); Klimova et al. (1999 ▶). For related structures, see: Butcher et al. (2007 ▶); Cui & Li (2010 ▶); Fun et al. (2010a ▶,b ▶); Jasinski et al. (2010a ▶,b ▶); Baktır et al. (2011 ▶).

Experimental

Crystal data

C₁₆H₁₂F₂N₂O
M _r = 286.28
Triclinic,
a = 6.2141 (9) Å
b = 6.7802 (8) Å
c = 17.9857 (9) Å
α = 96.727 (4)°
β = 90.254 (4)°
γ = 116.791 (5)°
V = 670.39 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 294 K
0.30 × 0.20 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID-S diffractometer
Absorption correction: multi-scan (Blessing, 1995 ▶) T _min = 0.968, T _max = 0.989
14070 measured reflections
2736 independent reflections
1011 reflections with I > 2σ(I)
R _int = 0.095

Refinement

R[F ² > 2σ(F ²)] = 0.062
wR(F ²) = 0.206
S = 0.94
2736 reflections
191 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681101587X/lh5239sup1.cif

e-67-o1292-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681101587X/lh5239Isup2.hkl

e-67-o1292-Isup2.hkl^{(134.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681101587X/lh5239Isup3.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
C4—H4⋯O1ⁱ	0.93	2.50	3.421 (5)	171
C11—H11⋯O1ⁱⁱ	0.93	2.39	3.296 (5)	165

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

Acknowledgments

ZB and MA thank the Unit of the Scientific Research Projects of Erciyes University, Turkey, for the research grant FBD-10–2949, and for support of the data collection at Atatürk University, Turkey. SS and BN thank Mangalore University and the UGC SAP for financial assistance for the purchase of chemicals. HSY thanks the UOM for sabbatical leave.

supplementary crystallographic information

Comment

Pyrazolines have been reported to exhibit a broad spectrum of biological activies such as antitumor, antibacterial, antifungal, antiviral, antiparasitic, anti-tubercular and insecticidal activities (Hes et al., 1978; Manna et al., 2005; Amir et al., 2008). Some of these compounds have also antioxidant, anti-diabetic, anaesthetic and analgesic properties (Sarojini et al., 2010; Regaila et al., 1979). In addition, pyrazolines have played a crucial part in the development of theory in heterocyclic chemistry and also used extensively in organic synthesis (Klimova et al., 1999 and Bhaskarreddy et al., 1997).

The crystal structure of some pyrazoline derivatives viz., 3-(4-methylphenyl)-5-[4-(methylthio)phenyl]-4,5-dihydro-1H-pyrazole-1-carbaldehyde (Butcher et al., 2007) and 5-(2-hydroxyphenyl)-3-methyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde (Cui & Li, 2010) have been reported. In view of the importance of pyrazoline derivatives and in continuation of our work on synthesis of various derivatives of 4,4'-diflouro chalcone (Fun et al., 2010a,b; Jasinski et al., 2010a,b; Baktır et al., 2011), the title compound (I) is synthesized and its crystal structure is reported herein.

The molecular structure of the title compound is shown in Fig. 1. The pyrazole ring adopts a slight envelope comformation with the methylene C atom (C8) deviating by 0.114 (3)Å from the mean-plane of the other four atoms (C7/C9/N1/N2 with maximum deviation 0.021 (3)Å for N1). The dihedral angles between the four essentially planar atoms of the pyrazole ring and fluoro-substituted benzene rings are 2.6 (2) and 82.2 (2)°, respectively. The dihedral angle between the two benzene rings is 83.7 (2)°. The crystal packing is stabilized by weak intermolecular C—H···O hydrogen bonds (Fig .2).

Experimental

A mixture of (2E)-1,3-bis(4-fluorophenyl)prop-2-en-1-one (2.44 g, 0.01 mol) and hydrazine hydrate (0.5 ml, 0.01 mol) in 20 ml formic acid was refluxed for 8 h. The reaction mixture was cooled and poured into 50 ml ice-cold water. The precipitate was collected by filtration and purified by recrystallization from ethanol. The single-crystal was grown from DMF by slow evaporation method and yield of the compound was 86%. (m. p.: 408 K).