2-[2-(Trifluoro­meth­yl)phen­yl]-2H-1-benzopyran-4(3H)-one

Bojana M Francuski; Branka Ivković; Ivana Stojanović; Sote Vladimirov; Djordje Francuski

doi:10.1107/S160053681201687X

. 2012 Apr 25;68(Pt 5):o1522. doi: 10.1107/S160053681201687X

2-[2-(Trifluoromethyl)phenyl]-2H-1-benzopyran-4(3H)-one

Bojana M Francuski ^a, Branka Ivković ^b,^*, Ivana Stojanović ^b, Sote Vladimirov ^b, Djordje Francuski ^c

PMCID: PMC3344626 PMID: 22590388

Abstract

In the title compound, C₁₆H₁₁F₃O₂, the γ-pyranone ring adopts an envelope conformation with the chiral C atom standing out of the ring plane. In the crystal, molecules are linked by C—H⋯O and C—H⋯F interactions.

Related literature

For general background to flavones, see: Harborne & Williams (2000 ▶). For related flavonoids, see: Benavente-García & Castillo (2008 ▶); Rodeiro et al. (2006 ▶). For related structures, see: Wera et al. (2012 ▶); Białońska et al. (2007 ▶); Krishnaiah et al. (2005 ▶); Wu et al. (2005 ▶). For van der Waals radii, see: Bondi (1964 ▶).

Experimental

Crystal data

C₁₆H₁₁F₃O₂
M _r = 292.25
Orthorhombic,
a = 8.2291 (9) Å
b = 22.020 (3) Å
c = 7.3355 (11) Å
V = 1329.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 293 K
0.18 × 0.02 × 0.02 mm

Data collection

Oxford Diffraction Xcalibur Sapphire3 Gemini diffractometer
4585 measured reflections
2558 independent reflections
1462 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.087
wR(F ²) = 0.109
S = 1.12
2558 reflections
190 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 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 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶), PLATON (Spek, 2009 ▶) and PARST (Nardelli, 1995 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S160053681201687X/kj2198sup1.cif

e-68-o1522-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681201687X/kj2198Isup2.hkl

e-68-o1522-Isup2.hkl^{(123.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681201687X/kj2198Isup3.mol

Supplementary material file. DOI: 10.1107/S160053681201687X/kj2198Isup4.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
C3—H3⋯O2ⁱ	0.93	2.54	3.311 (5)	140
C5—H5⋯F3ⁱⁱ	0.93	2.54	3.313 (5)	141

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

Acknowledgments

We would like to thank Dr Vladimir Divjaković and Dr Agneš Kapor for the data acquisition and Dr Goran A. Bogdanović for his valuable suggestions. Our work was supported by Scientific Research Grants from the Serbian Ministry of Science and Technology (grant Nos. OI172041, ON172035 and ON173008).

supplementary crystallographic information

Comment

The title compound belongs to the group of flavanones which occur predominantly in citrus fruits. Citrus flavonoids were reported (Benavente-García & Castillo, 2008) as having antimicrobial, antifungal, antiviral, anti–allergenic, anti-inflammatory (Harborne & Williams, 2000) and antioxidant (Rodeiro et al., 2006) properties. Case control studies suggest that flavonoids may reduce the risk of cardiovascular disease and stroke. Considering the wide spectrum of activities of natural flavonoids further structure modification of these molecules is aimed to enhance their interaction with the target sites in cells.

The title compound adopts a typical conformation of flavanones with the γ–pyranone ring adopting the envelope conformation. In this conformation the carbon atoms C1, C6, C7, C8 and oxygen O1 are nearly coplanar with a root mean square deviation from the mean plane of 0.035 Å, while the C9 carbon atom is standing out from this plane with an atom–to–plane distance of 0.652 (6) Å. All bond lengths and angles in the title compound show usual values for this type of compounds (Wera et al., 2012; Białońska et al., 2007; Krishnaiah et al., 2005; Wu et al., 2005). In this crystal packing of the title compound there are 4 intramolecular, 2 intermolecular (C—H···O and C—H···F) and one π–π interaction. All of the fluoride atoms participate in weak intramolecular C—H···F interactions (Fig. 1) with H···F distances equal or shorter than 2.50 Å, which is shorter than the sum of their Van der Waals radii (Bondi, 1964). Two of the fluoride atoms interact with the hydrogen atom connected to the chiral carbon atom C9 while the third fluoride atom interacts with one of the phenyl hydrogen atoms (Table 1). The dihedral angle between Cg1 and Cg2 rings in previously published structures of flavanones (Wera et al., 2012; Białońska et al., 2007; Krishnaiah et al., 2005; Wu et al., 2005) is in the range from 55 to 75° while the corresponding dihedral angle in the case of the title compound is 66.06 (15)°.

The flavanone molecules are connected into rows by the C3—H3···O2 intermolecular interaction forming chains down the crystallographic a axis (Fig. 2). The second intermolecular interaction, C5—H5···F3, connects the molecules into another chain in the direction of the screw axis following the crystallographic c axis, thus forming a two dimensional net of molecules (Fig. 3). Strings of molecules along the crystallographic c axis are further connected by π–π interactions (Fig. 4). Perpendicular distance from the centroid of one Cg1 ring, molecule at (x, y, z), to the plane of the second Cg1 ring, molecule at (1 - x, 2 - y, 1/2 + z), and vice versa are 3.70 and 3.62 Å respectively, while the distance between the ring centroids measures 4.101 (3) Å. The Cg1 ring planes of molecules at (x, y, z) and (1 - x, 2 - y, 1/2 + z) are nearly parallel with the dihedral angle being 5.59 (3)°.

Experimental

The proposed compound was prepared in two steps. The first step in the synthetic route consisted of the condensation of 2-hydroxy acetophenone with 2-trifluoromethylbenzaldehyde to give an α,β-unsaturated ketone (chalcone). In the second step the obtained chalcone was dissolved under stirring in a 50:50 water/ethanol mixture. The pH was set to 9.0 with 0.1 M NaOH and the reaction mixture was refluxed for 2 h after which it was cooled over night to room temperature. Small crystals of the title compound formed in the reaction vessel and, after draining excess fluid, the crystals were dried at room temperature.