1-(2,3,4,5,6-Penta­methyl­benz­yl)-2-(pyridin-2-yl)-1H-benzimidazole

Fırat Anĝay; Ömer Çelik; Orhan Barlık; Mahmut Ulusoy

doi:10.1107/S1600536814007934

. 2014 Apr 16;70(Pt 5):o563–o564. doi: 10.1107/S1600536814007934

1-(2,3,4,5,6-Pentamethylbenzyl)-2-(pyridin-2-yl)-1H-benzimidazole

Fırat Anĝay ^a, Ömer Çelik ^b,^c,^*, Orhan Barlık ^d, Mahmut Ulusoy ^d

PMCID: PMC4011285 PMID: 24860369

Abstract

In the title compound, C₂₄H₂₅N₃, the benzimidazole ring system is essentially planar, with an r.m.s. deviation of 0.017 Å, and forms dihedral angles of 7.81 (5) and 87.61 (4)° with the pyridine and benzene rings, respectively. An intramolecular C—H⋯N hydrogen bond is observed. In the crystal, molecules are stacked along the a axis by weak C—H⋯π interactions.

Related literature

For the use of 2-(2-pyridyl)benzimidazole in coordination chemistry, see: Sahin et al. (2010 ▶); 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 ▶). For the use of N—N-type ligand systems involving 2,2′-bipyridine, see: Lippert (1999 ▶); Wong & Giandomenico (1999 ▶), Kelland & Farrell (2000 ▶). For related structures, see: Çelik et al. (2007 ▶, 2009 ▶, 2014 ▶).

Experimental

Crystal data

C₂₄H₂₅N₃
M _r = 355.47
Monoclinic,
a = 5.3470 (3) Å
b = 21.0622 (12) Å
c = 17.0379 (9) Å
β = 97.699 (3)°
V = 1901.50 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 296 K
0.25 × 0.20 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (Blessing, 1995 ▶) T _min = 0.982, T _max = 0.989
25354 measured reflections
3741 independent reflections
3056 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.150
S = 1.04
3741 reflections
254 parameters
H-atom parameters constrained
Δρ_max = 0.24 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: SHELXL2013 (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/S1600536814007934/rz5115sup1.cif

e-70-0o563-sup1.cif^{(1MB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814007934/rz5115Isup2.hkl

e-70-0o563-Isup2.hkl^{(179.7KB, hkl)}

Click here for additional data file.^{(8KB, cml)}

Supporting information file. DOI: 10.1107/S1600536814007934/rz5115Isup3.cml

CCDC reference: 996309

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

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

Cg is the centroid of the C7–C12 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C13—H13A⋯Cg ⁱ	0.97	2.91	3.6941 (18)	139
C13—H13B⋯N1	0.97	2.30	3.029 (2)	131

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are indebted to the X-ray laboratory of Dicle University Science and the Technology Application 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 (Sahin et al., 2010; 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). Lots of platinum chemistry bearing N—N type ligand systems involving 2,2'-bipyridine has been reported aimed at the design of drugs having less serious side-effects than those of cisplatin, or which could extend the scope of Pt based chemotherapy to tumours (Lippert, 1999; Wong & Giandomenico, 1999; Kelland & Farrell, 2000).

The molecular structure of the title compound is shown in Fig. 1. Bond lengths and angles are in good agreement with those reported for related structures (Çelik et al., 2007; Çelik et al., 2009; Çelik et al., 2014). The benzimidazole ring system is substantially planar, the maximum deviation being 0.027 (2) Å for atom C8, and forms dihedral angles of 7.81 (5) and 87.61 (4)° with the mean planes through the pyridine (N1/C1–C5) and phenyl (C14–C19) rings, respectively. An intramolecular C—H···N hydrogen bond is present (Table 1). In the crystal structure (Fig. 2), molecules are stacked along the a axis by weak C—H···π hydrogen interactions (Table 1) involving the C7—C12 benzene ring of the benzimidazole moiety.

2. Experimental

NaH (60%) (398 mg, 11.0 mmol) was washed two times with dry hexane, filtered off via cannula and a solution of the 2-pyridiylbenzimidazole (1.95 g, 10.0 mmol) in dry toluene (10 ml) was added, then the solution was heated at 90°C for 24 h. Evolution of hydrogen was observed at this temperature. 2,3,4,5,6-Pentamethylbenzyl bromide (2.45 g, 10.0 mmol) was added to this mixture at room temperature and then heated again at 90°C for 1 day. Then volatiles were evaporated in vacuum to dryness. The residue was dissolved in CH₂C_l2 and filtered via cannula on celite. The desired product was obtained after concentration of CH₂C_l2 (15 ml) and then precipitated with hexane (30 ml). The off-white solid obtained in 86% yield. M. p. 416–418 K. ¹H NMR (400 MHz, CDCl₃, δ p.p.m.): 1.26 (s, 6H, o-(CH₃)₂); 1.36(s, 6H, m-(CH₃)₂); 2.13–2.20 (s, 3H, p-CH₃); 5.50 (s, 2H, N—CH₂); 6.86 (s, 1H, Ar—CH); 7.11 (s, 1H, Ar—CH); 7.26 (s, 1H, Ar—CH); 7.35 (s, 1H, Ar—CH); 7.49 (s, 1H, Ar—CH); 8.46 (s, 1H, Ar—CH); 10.19 (s, 2H, Ar—CH). ¹³C NMR (100.56 MHz, CDCl₃, δ p.p.m.): 17.0; 17.4; 29.6; 31.7; 34.4; 35.2; 48.7; 49.3; 56.2; 117.9; 121.2; 122.4; 125.5; 126.5; 133.8; 134.0; 137.5; 140.7; 158.0; 167.9.