1-[2-(2,6-Dichloro­benz­yloxy)-2-(2-fur­yl)eth­yl]-1H-benzimidazole

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

doi:10.1107/S1600536808020758

. 2008 Jul 9;64(Pt 8):o1437. doi: 10.1107/S1600536808020758

1-[2-(2,6-Dichlorobenzyloxy)-2-(2-furyl)ethyl]-1H-benzimidazole

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

PMCID: PMC2962068 PMID: 21203152

Abstract

In the molecule of the title compound, C₂₀H₁₆Cl₂N₂O₂, the planar benzimidazole ring system is oriented with respect to the furan and dichlorobenzene rings at dihedral angles of 53.39 (6) and 31.04 (5)°, respectively. In the crystal structure, intermolecular C—H⋯Cl hydrogen bonds link the molecules into centrosymmetric R ₂ ²(8) dimers. These dimers are connected via a C—H⋯π contact between the benzimidazole and the furan rings, and π–π contacts between the benzimidazole and dichlorobenzene ring systems [centroid–centroid distances = 3.505 (1), 3.567 (1), 3.505 (1) and 3.567 (1) Å].

Related literature

For general background, see: Brammer & Feczko (1988 ▶); Özel Güven et al. (2007a ▶,b ▶). For related literature, see: Song & Shin (1998 ▶); Freer et al. (1986 ▶); Peeters et al. (1996 ▶); Peeters et al. (1979a ▶,b ▶); Caira et al. (2004 ▶). For ring motif details, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₀H₁₆Cl₂N₂O₂
M _r = 387.25
Orthorhombic,
a = 12.7720 (3) Å
b = 12.9761 (2) Å
c = 21.9732 (5) Å
V = 3641.63 (13) Å³
Z = 8
Mo Kα radiation
μ = 0.37 mm⁻¹
T = 120 (2) K
0.50 × 0.40 × 0.20 mm

Data collection

Bruker Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2007 ▶) T _min = 0.835, T _max = 0.929
27000 measured reflections
4181 independent reflections
3311 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.122
S = 1.10
4181 reflections
300 parameters
All H-atom parameters refined
Δρ_max = 0.50 e Å⁻³
Δρ_min = −0.49 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 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808020758/si2098sup1.cif

e-64-o1437-sup1.cif^{(21KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808020758/si2098Isup2.hkl

e-64-o1437-Isup2.hkl^{(124.7KB, 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
C19—H19⋯Cl2ⁱ	1.00 (2)	2.76 (2)	3.7470 (19)	172.0 (15)
C1—H1⋯Cg1ⁱⁱ	0.95 (2)	2.533 (19)	3.441 (2)	158.8 (16)

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

Acknowledgments

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

supplementary crystallographic information

Comment

In recent years, there has been increasing interest in synthesis of heterocyclic compounds having biological and commercial importances. Clotrimazole (Song & Shin, 1998), econazole (Freer et al., 1986), ketoconazole (Peeters et al., 1979a) and miconazole (Peeters et al., 1979b) are well-known imidazole ring containing, while itraconazole (Peeters et al., 1996) and fluconazole (Caira et al., 2004) are 1H-1,2,4-triazole ring containing, azole derivatives. They have been developed for clinical uses as antifungal agents (Brammer & Feczko, 1988). Lately, similar structures to miconazole and econazole have been reported to show antibacterial activity more than antifungal activity (Özel Güven et al., 2007a,b). In these structures, benzimidazole ring has been found in place of the imidazole ring of miconazole and econazole. We report herein the crystal structure of title benzimidazole derivative.

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 furan and dichlorobenzene rings at dihedral angles of 53.39 (6)° and 31.04 (5)°, respectively. Atoms C8, C9 and C14 are 0.063 (2), 0.065 (2) and -0.039 (2) Å away from the ring planes of benzimidazole, furan and dichlorobenzene, respectively. So, they are coplanar with the adjacent rings. The N1-C8-C9, C9-O2-C14 and C8-C9-C10, O2-C9-C10 bond angles are nearly equal, while O2-C9-C8 and O2-C14-C15 bond angles are different from each other. The N1-C1-N2, N2-C2-C7 and C2-C7-C6 bond angles are enlarged, while C5-C6-C7 bond angle is narrowed. In dichlorobenzene ring, the C15-C16-C17 and C15-C20-C19 bond angles are enlarged, while C16-C15-C20 bond angle is highly narrowed (Table 1), probably due to the intermolecular C-H···Cl hydrogen bonds (Table 2).

In the crystal structure, intermolecular weak C-H···Cl hydrogen bonds (Table 2) link the molecules to form a R²₂(8) ring motif (Fig. 2) (Bernstein et al., 1995), in which they may be effective in the stabilization of the structure. The C—H···π contact (Table 2) between the benzimidazole and the furan rings and π—π contacts between the benzimidazole and dichlorobenzene ring systems Cg2···Cg4ⁱ, Cg3···Cg4ⁱ, Cg4···Cg2ⁱⁱ and Cg4···Cg3ⁱⁱ [symmetry codes: (i) -1/2 + x, 1/2 - y, 1 - z; (ii) 1/2 + x, 1/2 - y, 1 - z, where Cg2, Cg3 and Cg4 are centroids of the rings (N1/N2/C1/C2/C7), (C2-C7) and (C15-C20), respectively] further stabilize the structure, with centroid–centroid distances of 3.505 (1), 3.567 (1), 3.505 (1) and 3.567 (1) Å, respectively.

Experimental

The title compound, was synthesized by the reaction of 2-(1H-benzimidazol -1-yl)-1-(furan-2-yl)ethanol (Özel Güven et al., 2007b) with NaH and appropriate benzyl halide. A solution of alcohol (150 mg, 0.657 mmol) in DMF (1.5 ml) was added to NaH (19.7 mg, 0.821 mmol) in small fractions. The appropriate benzyl halide (158 mg, 0.657 mmol) in DMF (0.8 ml) was then added dropwise. The mixture was stirred at room temperature for 2 h, and the excess hydride was decomposed with a small amount of methyl alcohol. After evaporation to dryness under reduced pressure, the crude residue was suspended with water and extracted with methylene chloride. The organic layer was dried over anhydrous sodium sulfate, and then evaporated to dryness. The crude residue was purified by chromatography on a silica-gel column using chloroform-methanol as eluent. Crystals suitable for X-ray analysis were obtained by the recrystallization of the ether from a mixture of hexane/ethyl acetate (1:2) (yield; 124 mg, 49%).