1-(4-Fluoro­benz­yl)-2-(pyridin-2-yl)-1H-benzimidazole

Ömer Çelik; Fırat Anĝay; Mustafa Gündoĝan; Mahmut Ulusoy

doi:10.1107/S1600536814005947

. 2014 Mar 26;70(Pt 4):o485. doi: 10.1107/S1600536814005947

1-(4-Fluorobenzyl)-2-(pyridin-2-yl)-1H-benzimidazole

Ömer Çelik ^a,^*, Fırat Anĝay ^b, Mustafa Gündoĝan ^c, Mahmut Ulusoy ^c

PMCID: PMC3998549 PMID: 24826178

Abstract

In the title compound, C₁₉H₁₄FN₃, the dihedral angles between the benzimidazole unit (r.m.s. deviation= 0.017 Å) and the pyridine and benzene rings are 24.46 (4) and 81.87 (3)°, respectively. In the crystal, molecules are stacked along the a-axis direction by C—H⋯π interactions.

Related literature

For the use of 2-(2-pyridyl)benzimidazole in coordination chemistry, see: Boca et al. (1997 ▶); De Castro et al. (1991 ▶); Khalil et al. (2001 ▶); Maekawa et al. (1994 ▶). For deprotonation of the NH group in 2-(2-pyridyl)benzimidazole, see: Chiswell et al. (1964 ▶); Harkins et al. (1956 ▶); Haga (1983 ▶). For functionalization of 2-(2-pyridyl)benzimidazole, see: Ali et al. (1998 ▶); Hossain et al. (2001 ▶); Sahin et al. (2010 ▶). For related structures, see: Çelik et al. (2007 ▶, 2009 ▶).

Experimental

Crystal data

C₁₉H₁₄FN₃
M _r = 303.33
Monoclinic,
a = 4.7363 (5) Å
b = 15.4102 (17) Å
c = 20.953 (2) Å
β = 95.363 (8)°
V = 1522.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.2 × 0.2 × 0.2 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (Blessing, 1995 ▶) T _min = 0.984, T _max = 0.984
13325 measured reflections
3133 independent reflections
2355 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.103
S = 0.93
3133 reflections
208 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; 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 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536814005947/bq2393sup1.cif

e-70-0o485-sup1.cif^{(24.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814005947/bq2393Isup2.hkl

e-70-0o485-Isup2.hkl^{(146.7KB, hkl)}

Click here for additional data file.^{(5.9KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814005947/bq2393Isup3.cml

CCDC reference: 992223

Additional supporting information: crystallographic information; 3D view; checkCIF report

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

Cg is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C13—H13A⋯Cg ⁱ	0.97	2.94	3.486 (2)	117

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are indebted to the X-ray laboratory of Dicle University Scientific and Technological Applied and Research Center, Diyarbakir, Turkey, for use of the X-ray diffractometer.

supplementary crystallographic information

1. Comment

The N—N type ligand system, 2-(2-pyridyl)benzimidazole has a venerable history in coordination chemistry (Harkins et al., 1956; Chiswell et al., 1964; De Castro et al., 1991; Maekawa et al., 1994; Khalil et al., 2001; Boca et al., 1997). Many of the reported complexes of 2-(2-pyridyl) benzimidazole have been of interest because of the possibility of deprotonation of the NH group of the imidazole unit, converting the ligand from neutral to anionic form with different properties (Harkins et al., 1956; Chiswell et al., 1964; Haga, 1983). The functionalization of 2-(2-pyridyl)benzimidazole at the externally directed NH position allows simple incorporation of 2-(2-pyridyl)benzimidazole units (Sahin et al., 2010; Hossain et al., 2001; Ali et al., 1998).

The molecular structure of title compound is shown in Figure 1. In the compound, the bond lengths of F—C17, N3—C12 and C1—C2 are 1.3671 (18) Å, 1.336 (2) Å and 1.373 (2) Å, respectively. C18—C17—F and N3—C8—C7 bond angles are 118.58 (13)° and 117.91 (13)°. F—C17—C18—C19 and C12—N3—C8—C7 torsion angles are -178.74 (15)° and -178.95 (14)°. Similar results are observed in the study of (Çelik et al., 2009; Çelik et al., 2007).

In the title compound, (Fig. 1), four planes were named as P1(N1/C5/C6/N2/C7), P2(N3/C8/C9/C10/C11/C12), P3(C1/C2/C3/C4/C5/C6), P4(C14/C15/C16/C17/C18/C19) and P5(N1/C5/C4/C3/C2/C1/C6/N2/C7). The five- and six-membered rings (N1/C5/C6/N2/C7) and (C1—C6) of the benzimidazole groups are almost co-planar with maximum deviations of -0.011Å for C5 and -0.017 Å for C6, respectively. Moreover the maximum deviations from P2 plane of C8, P4 plane of C17 and P5 plane of N2 are -0.007 Å, -0.003 Å and -0.034 Å, respectively.

In the compound, dihedral angles between P1—P2, P1—P3, P1—P4, P1—P5, P2—P3, P2—P4, P2—P5, P3—P4, P3—P5 and P4—P5 are 23.37 (5)°, 2.29 (5)°, 81.87 (3)°, 1.18 (4)°, 25.51 (5)°, and 73.68 (4)°, 24.46 (4)°, 81.94 (4)°, 1.11 (4)° and 81.87 (3)° respectively.

There is intermolecular C—H···Cg(π) type hydrogen bonds interactions in the crystal structure with the contact distances of 2.9345 Å between acceptor and donor atom and π-ring system defined as C1–C6 ring (Table 1.) and the molecules are stacked along a-axis with these C—H···π type hydrogen-bond interactions (Figure 2.).

2. Experimental

A solution of the 2-pyridiylbenzimidazole (1.95 g, 10.0 mmol) in toluene (10 ml) and KOH was added (616 mg, 11.0 mmol) and stirred at 60 °C for 4 h. To this reaction mixture 4-florobenzyl bromide (1.89 g, 10.0 mmol) was added, then heated at this temperature for 24 h. Then volatiles were evaporated in vacuum to dryness. The residue was dissolved in CH₂Cl₂ and filtered via cannula on celite. The desired product was obtained after concentration of CH₂Cl₂ (15 ml) and then precipitating with hexane (30 ml). The off-white solid obtained in 80% yield. M.p. 94 °C. ¹H NMR (400 MHz, CDCl₃, δ p.p.m.): 6.13 (s, 2H, N—CH₂); 6.90–6.94 (t, J = 8.0 Hz, 2H, Ar—CH); 7.15–7.18 (m, 2H, Ar—CH); 7.26–7.32 (m, 4H, Ar—CH); 7.81–7.86 (m, 2H, Ar—CH); 8.44 (d, J = 8.0 Hz, ¹H, Ar—CH); 8.62 (d, J = 4.0 Hz, ¹H, Ar—CH). ¹³C NMR (100.56 MHz, CDCl₃, δ p.p.m.): 110.2; 115.1; 120.1; 122.2; 123.8; 124.3; 128.0; 142.2; 148.5; 150.1; 161.4. ¹⁹F NMR (376.266 MHz, CDCl₃, δ p.p.m.): - 115.59.