2-(3,4-Di­fluoro­phen­yl)-1H-benzimidazole

M S Krishnamurthy; Nikhath Fathima; H Nagarajaiah; Noor Shahina Begum

doi:10.1107/S1600536813028559

. 2013 Oct 23;69(Pt 11):o1689. doi: 10.1107/S1600536813028559

2-(3,4-Difluorophenyl)-1H-benzimidazole

M S Krishnamurthy ^a, Nikhath Fathima ^a, H Nagarajaiah ^a, Noor Shahina Begum ^a,^*

PMCID: PMC3884342 PMID: 24454118

Abstract

In the title molecule, C₁₃H₈F₂N₂, the dihedral angle between the benzimidazole ring system and the difluoro-substituted benzene ring is 30.0 (1)°. In the crystal, molecules are linked by N—H⋯N hydrogen bonds, forming chains along [010]. In addition, weak C—H⋯F hydrogen bonds connect chains into a two-dimensional network parallel to (001). A weak C—H⋯π interaction is observed between an H atom of the benzimidazole ring sytem and the π system of the difluoro-substituted benzene ring.

Related literature

For the therapeutic and medicinal properties of benzimidazole derivatives, see: Chimirri et al. (1991 ▶); Ishihara et al. (1994 ▶); Kubo et al. (1993 ▶). For related structures, see: Rashid et al. (2007 ▶); Jayamoorthy et al. (2012 ▶); Yoon et al. (2012 ▶); Fathima et al. (2013 ▶). graphic file with name e-69-o1689-scheme1.jpg

Experimental

Crystal data

C₁₃H₈F₂N₂
M _r = 230.21
Orthorhombic,
a = 8.7195 (17) Å
b = 9.9454 (19) Å
c = 23.389 (4) Å
V = 2028.2 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 100 K
0.18 × 0.16 × 0.16 mm

Data collection

Bruker SMART APEX CCD detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.982, T _max = 0.984
13072 measured reflections
2209 independent reflections
1558 reflections with I > 2σ(I)
R _int = 0.067

Refinement

R[F ² > 2σ(F ²)] = 0.059
wR(F ²) = 0.156
S = 1.01
2209 reflections
154 parameters
H-atom parameters constrained
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; 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, 2012 ▶) and CAMERON (Watkin et al., 1996 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813028559/lh5659sup1.cif

e-69-o1689-sup1.cif^{(16.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813028559/lh5659Isup2.hkl

e-69-o1689-Isup2.hkl^{(106.5KB, hkl)}

Click here for additional data file.^{(4.3KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813028559/lh5659Isup3.cml

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

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

Cg is the centroid of the ring C9–C13 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N2ⁱ	0.88	2.04	2.874 (3)	158
C13—H13⋯F2ⁱⁱ	0.95	2.51	3.379 (3)	153
C3—H3A⋯Cg ⁱⁱⁱ	0.95	2.89	3.529 (3)	125

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

Acknowledgments

NSB is thankful to the University Grants Commission (UGC), India, for financial assistance.

supplementary crystallographic information

1. Comment

Benzimidazole is a bicyclic heterocycle system consisting of two nitrogen atoms and fused phenyl ring. It shows wide variety of pharmacological activities such as antihypertensive (Kubo et al., 1993), anti-HIV (Chimirri et al., 1991), antiulcer (Ishihara et al., 1994). The bond lengths and bond angles of the benzimidazole moiety in the title compound are in good agreement with those observed in other benzimidazole derivatives (Jayamoorthy et al., 2012; Yoon et al., 2012).

The molecular structure of the title compound is shown in Fig. 1. The dihedral angle between the benzimidazole ring system and difluoro-substituted benzene ring is 30.0 (1)°. This value is slightly larger than for the benzene ring with a trifluoromethoxy substituent at the para position (Fathima et al., 2013), and slightly smaller for a ring with a fluorine atom at the para position (Rashid et al., 2007). In the crystal, molecules are linked by intermolecular N1—H1···N2ⁱ and C9—H9···F2ⁱⁱ hydrogen bonds (see Table 1 for symmetry codes). The former interaction forms extended chains parallel to the b-axis and the latter results in one-dimensional chains along the a-axis (Fig. 2). Overall a two-dimensional network parallel to (001) is formed. In addition, a weak C—H···π interaction of the type C3—H3A···Cg (Cg being the centroid of the ring C9—C13 ring) is observed (Table 1).

2. Experimental

The title compound was synthesized by refluxing 3,4-difluorobenzaldehyde (20 mmol,0.28 g) and o-phenyldiamine (20 mmol,0.22 g) in benzene (3.0 ml) for 6hrs on a water bath. The reaction mixture was cooled. The solid separated, was filtered and dried (Yield; 0.34 g (75%) and M.P. 533 K). Yellow crystals of the title compound were obtained by slow evaporation of a solution of the title compound in ethyl acetate.