2-(2-Benzyl­oxyphen­yl)-1H-benzimid­azole

Gabriel Navarrete-Vázquez; Hermenegilda Moreno-Diaz; Samuel Estrada-Soto; Hugo Tlahuext

doi:10.1107/S1600536808004510

. 2008 Feb 20;64(Pt 3):o608. doi: 10.1107/S1600536808004510

2-(2-Benzyloxyphenyl)-1H-benzimidazole

Gabriel Navarrete-Vázquez ^a, Hermenegilda Moreno-Diaz ^a, Samuel Estrada-Soto ^a, Hugo Tlahuext ^b,^*

PMCID: PMC2960883 PMID: 21201944

Abstract

The asymmetric unit of the title compound, C₂₀H₁₆N₂O, contains two molecules. The dihedral angles between the benzimidazole ring systems and the attached benzene rings are 10.6 (5) and 13.7 (5)°. The conformers are linked by bifurcated three-centre hydrogen bonds, forming chains along the diagonal of the a b plane. The packing is further stabilized by π–π and C—H⋯π interactions.

Related literature

For general background, see: Desiraju & Steiner (1999 ▶); Lehn (1990 ▶); Saenger (1984 ▶); Wakelin (1986 ▶). For related structures, see: Estrada-Soto et al. (2006 ▶); Moreno-Diaz et al. (2006 ▶); Navarrete-Vázquez et al. (2006 ▶).

Experimental

Crystal data

C₂₀H₁₆N₂O
M _r = 300.35
Monoclinic,
a = 11.526 (2) Å
b = 17.210 (3) Å
c = 15.866 (3) Å
β = 90.52 (3)°
V = 3147.0 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 (2) K
0.31 × 0.21 × 0.17 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T _min = 0.976, T _max = 0.987
7808 measured reflections
2830 independent reflections
2691 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.100
S = 1.17
2830 reflections
423 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT-Plus NT (Bruker, 2001 ▶); data reduction: SAINT-Plus NT; program(s) used to solve structure: SHELXTL-NT (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL-NT; molecular graphics: SHELXTL-NT; software used to prepare material for publication: PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808004510/sj2464sup1.cif

e-64-0o608-sup1.cif^{(27.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808004510/sj2464Isup2.hkl

e-64-0o608-Isup2.hkl^{(138.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the C27/N4/C26/C21/N3 imidazole ring, and Cg2, Cg3 and Cg4 are the centroids of the C28–C33, C15–C20 and C35–C40 benzene rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1	0.89 (4)	2.20 (3)	2.667 (4)	112 (3)
N1—H1⋯N4ⁱ	0.89 (4)	2.18 (3)	3.008 (4)	154 (3)
N3—H3A⋯O2	0.83 (4)	2.20 (5)	2.670 (4)	117 (4)
N3—H3A⋯N2ⁱⁱ	0.83 (4)	2.18 (5)	2.918 (4)	148 (4)
C14—H14A⋯Cg1ⁱ	0.97	2.88	3.736 (4)	148
C14—H14B⋯Cg4ⁱⁱⁱ	0.97	2.92	3.721 (4)	141
Cg3⋯Cg2ⁱ			3.859 (2)

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

Acknowledgments

This work was supported by the Consejo Nacional de Ciencia y Tecnología (CONACyT) under grant Nos. 3562P-E and PROMEP-SEP UAEMOR-PTC-131 (GNV).

supplementary crystallographic information

Comment

Hydrogen bonding and π–π interactions are among the principal forces which determine the intercalation of drugs into DNA (Saenger, 1984; Wakelin, 1986), together with self-assembly and recognition in some chemical and biological systems (Lehn, 1990). Recently, we have reported the synthesis of a small library of 2-arylbenzimidazole compounds that show spasmolytic and relaxant activity (Moreno-Diaz et al., 2006; Navarrete-Vázquez et al., 2006; Estrada-Soto et al., 2006). In order to extend our research on the relationship between the structure of benzimidazole derivatives and their pharmacological activity we have determined the crystal structure of (I).

The asymmetric unit of (I) contains two conformers (Ia, Ib) (Fig. 1). Bond lengths between equivalent non-H atoms of each conformer are similar, with differences less than 3 s.u. The dihedral angles between the benzimidazole ring systems and the 2-benzyloxyphenyl substituents in Ia and Ib are 10.6 (5) and 13.7 (5)°, respectively. Both molecules display bifurcated N—H···N and N—H···O hydrogen bonds, Table 1 (Desiraju & Steiner, 1999). These hydrogen bonds interconnect molecules into chains running between the a and b axes (Fig. 2). Packing is further stabilized by C—H···π interactions involving the methylene H atoms on C14 of molecule Ia with the C27N4C26C21N3 benzimidazole ring (centroid Cg1) and the C28–C33 benzene ring (centroid Cg4) of two adjacent molecules of Ib (Fig. 3, Table 1). In the crystal packing there are also π–π interactions between adjacent molecules Ia and Ib, with a distance between the centroids of the C15–C20 (Cg3) and C28–C33 (Cg2) benzene rings of 3.859 (2) Å (Fig. 3, Table 1). In conclusion, this crystal structure illustrates four types of cooperative intra and intermolecular interactions: offset π–π stacking and C—H···π interactions as well as classical N—H···N and N—H···O hydrogen bonds.

Experimental

The title compound, (I), was synthesized according to the method of Moreno-Diaz et al. (2006). Single crystals of (I) were obtained from methanol with yield 2.07 g, 75%.