1-(1-Adamantylmeth­yl)-1H-benzimidazole

Jarmila Černochová; Marek Nečas; Ivo Kuřitka; Robert Vícha

doi:10.1107/S1600536811041018

. 2011 Oct 12;67(Pt 11):o2906. doi: 10.1107/S1600536811041018

1-(1-Adamantylmethyl)-1H-benzimidazole

Jarmila Černochová ^a, Marek Nečas ^b, Ivo Kuřitka ^c, Robert Vícha ^a,^*

PMCID: PMC3247322 PMID: 22219940

Abstract

The asymmetric unit of the title compound, C₁₈H₂₂N₂, contains two independent molecules which differ slightly with respect to the torsion angles involving the atoms joining the adamantyl and benzimidazole groups. The bond angles in the adamantane cage vary within the range 108.27 (9)–110.55 (10)°. The benzimidazole ring system in both molecules is essentially planar, the maximum deviations from the best planes being 0.0134 (15) and 0.0229 (14) Å. In the crystal, weak C—H⋯π interactions link the molecules.

Related literature

For the synthesis, spectroscopic characterization and biological activity of the title compound, see: Hille et al. (2011 ▶). For background to C(sp ²)—H⋯π interactions, see: Takahashi et al. (2010 ▶). For two polymorphs of a related structure, see: Lei & Zhou (2009 ▶); Zhang et al. (2010 ▶).

Experimental

Crystal data

C₁₈H₂₂N₂
M _r = 266.38
Monoclinic,
a = 22.0249 (9) Å
b = 6.4628 (1) Å
c = 22.2739 (8) Å
β = 118.694 (5)°
V = 2781.2 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 120 K
0.30 × 0.20 × 0.20 mm

Data collection

Oxford Diffraction Xcalibur Sapphire2 diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T _min = 0.928, T _max = 1.000
32353 measured reflections
4899 independent reflections
3314 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.064
S = 0.83
4899 reflections
361 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811041018/lh5341sup1.cif

e-67-o2906-sup1.cif^{(25.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811041018/lh5341Isup2.hkl

e-67-o2906-Isup2.hkl^{(240KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811041018/lh5341Isup3.cml

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

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

Cg1 is the centroid of the C2–C7 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯Cg1ⁱ	0.95	3.07	3.9197 (16)	150

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Symmetry code: (i) Inline graphic .

Acknowledgments

The financial support of this work by the Czech Ministry of Education (project No. MSM 7088352101), the Internal Funding Agency of Tomas Bata University in Zlin, project No. IGA/6/FT/11/D and the Operational Program Research and Development for Innovations co-funded by the European Regional Development Fund (ERDF) and the national budget of the Czech Republic, within the framework of project Centre of Polymer Systems (reg. number: CZ.1.05/2.1.00/03.0111) is gratefully acknowledged.

supplementary crystallographic information

Comment

Title compound has been prepared as a suitable building block for benzimidazolium-based carbene ligands synthesis and recently, the biological activity related to treatment of cortisole-dependent diseases has been studied (Hille et al., 2011). Two polymorphs of a related structure have already been published (Lei & Zhou, 2009; Zhang et al., 2010).

Both crystallographically independent molecules in the asymmetric unit (Fig. 1) contain essentially planar 1H-benzo[d]imidazole heterocycle with a maximum deviations from the best plane being 0.0134 (15) Å for C2 and 0.0229 (14) Å for C21, respectively. The torsion angles C7—N1—C8—C9 and N1—C8—C9—C16 describing the mutual orientation of benzimidazole and adamantane groups are 95.31 (15)° and -179.38 (10)°, respectively. The corresponding angles in the other molecule are -92.89 (15)° and -177.52 (10)°, respectively. The crystal packing is stabilized via weak C—H···π interactions (Fig. 2, Table 1).

Experimental

Benzimidazole (0.40 g, 3.39 mmol) was dissolved in 40 cm³ of dry DMF and sodium hydride (0.2 g, 8.46 mmol) was added portionwise at room temperature. Into this mixture, 1-adamantylbromomethane (1.16 g, 5.09 mmol) was added and the mixture was stirred under argon for 5 days at 373 K. The reaction mixture was poured onto 100 g of crushed ice, extracted with 4 × 25 cm³ of dichloromethane and the collected organic portions were washed several times with distilled water, brine and dried over Na₂SO₄. The solvent was distilled off under reduced pressure and residual DMF was removed via azeotropic distillation with trichloromethane. The crude material was purified by crystallization (petroleum ether:ethyl acetate, 1:1, v:v) to yield 850 mg (94%) of colorless powder with mp=483–488 K. The crystal used for data collection was grown by spontaneous evaporation of a trichloromethane:methanol solution of the title compound at room temperature.