2-(1H-Benzimidazol-1-yl)-1-phenyl­ethanone

Özden Özel Güven; Taner Erdoğan; Simon J Coles; Tuncer Hökelek

doi:10.1107/S1600536808019107

. 2008 Jun 28;64(Pt 7):o1358. doi: 10.1107/S1600536808019107

2-(1H-Benzimidazol-1-yl)-1-phenylethanone

Özden Özel Güven ^a, Taner Erdoğan ^a, Simon J Coles ^b, Tuncer Hökelek ^c,^*

PMCID: PMC2961837 PMID: 21202976

Abstract

In the molecule of the title compound, C₁₅H₁₂N₂O, the planar benzimidazole system is oriented at a dihedral angle of 80.43 (5)° with respect to the phenyl ring. In the crystal structure, non-classical intermolecular C—H⋯N and C—H⋯O hydrogen bonds link the molecules into layers parallel to the ab plane.

Related literature

For general backgroud, see: Göker et al. (2002 ▶); Özden et al. (2004 ▶); Özel Güven et al. (2007a ▶,b ▶); Schar et al. (1976 ▶). For related literature, see: Peeters et al. (1997 ▶); Freer et al. (1986 ▶); Özel Güven et al. (2007 ▶).

Experimental

Crystal data

C₁₅H₁₂N₂O
M _r = 236.27
Monoclinic,
a = 5.0475 (2) Å
b = 11.2319 (6) Å
c = 10.3517 (5) Å
β = 96.620 (3)°
V = 582.96 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 120 (2) K
0.45 × 0.22 × 0.03 mm

Data collection

Bruker–Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2007 ▶) T _min = 0.962, T _max = 0.997
6918 measured reflections
2639 independent reflections
2265 reflections with I > 2σ(I)
R _int = 0.057

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.119
S = 1.06
2639 reflections
212 parameters
1 restraint
All H-atom parameters refined
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808019107/si2097sup1.cif

e-64-o1358-sup1.cif^{(17.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808019107/si2097Isup2.hkl

e-64-o1358-Isup2.hkl^{(39.6KB, hkl)}

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
C8—H81⋯N2ⁱ	0.95 (2)	2.43 (2)	3.355 (3)	165.2 (17)
C8—H82⋯O1ⁱⁱ	0.98 (2)	2.38 (2)	3.351 (3)	170.1 (17)

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

Acknowledgments

The authors acknowledge Zonguldak Karaelmas University Research Fund (grant No: 2004–13-02–16).

supplementary crystallographic information

Comment

Benzimidazoles have been shown to exhibit a large number of biological activities. Some of the substituted benzimidazole derivatives have highly potent antifungal (Göker et al., 2002) and antibacterial (Özden et al., 2004) activities. Recently, it has been reported that benzimidazole ring containing aryl ethers (Özel Güven et al., 2007a,b) similar to miconazole (Peeters et al., 1997) and econazole (Freer et al., 1986) structures have more antibacterial activities than antifungal activities (Schar et al., 1976). The crystal structure of oxime form of the benzimidazole substituted ketone has been reported previously (Özel Güven et al., 2007). We report herein the crystal structure of ketone, which is a starting material for biologically important molecules.

In the molecule of the title compound (Fig. 1) the bond lengths and angles are generally within normal ranges. The planar benzimidazole ring system is oriented with respect to the phenyl ring at a dihedral angle of 80.43 (5)°. Atoms C8 and C9 are -0.010 (2) Å and 0.044 (2) Å away from the ring planes of benzimidazole and phenyl, respectively. So, they are coplanar with the adjacent rings. The N1—C8—C9 [111.88 (15)°] and C8—C9—C10 [117.10 (15)°] bond angles are highly different from each other, while O1—C9—C8 [121.07 (16)°] and O1—C9—C10 [121.84 (17)°] bond angles are nearly equal. The N1—C1—N2 [114.25 (18)°], N2—C2—C7 [110.35 (17)°] and C2—C7—C6 [123.30 (18)°] bond angles are enlarged, while C5—C6—C7 [116.34 (19)°] bond angle is narrowed, probably due to the intermolecular C—H···N and C—H···O hydrogen bonds (Table 1).

In the crystal structure, non-classical intermolecular C—H···N and C—H···O hydrogen bonds (Table 1) link the molecules into layers parallel to the a,b plane (Fig. 2), in which they seem to be effective in the stabilization of the crystal structure.

Experimental

The title compound, was synthesized by the reaction of 2-bromo-1-phenyl- ethanone (Özel Güven et al., 2007a) with 1H-benzimidazole. A solution of 2-bromo-1-phenylethanone (4.00 g, 20.10 mmol) in dioxane-ether (8 ml) was added to an ice-cold solution of benzimidazole (11.87 g, 100.5 mmol) in methanol (20 ml) over 60 min under argon atmosphere. The reaction mixture was warmed to ambient temperature and stirred for an additional 18 h, diluted with water (20 ml), and then extracted with chloroform. Organic extract was dried over anhydrous sodium sulfate, concentrated under reduced pressure, and then chromatographed on neutral silica-gel column using chloroform-methanol as eluent. Crystals suitable for X-ray analysis were obtained by the recrystallization of the ketone from a mixture of hexane/ethyl acetate (1:2) (yield; 2.85 g, 60%).