2-(4-Methyl­sulfanylphen­yl)-1H-benzimidazol-3-ium bromide

Mohamed Ziaulla; M N Manjunatha; Ravish Sankolli; K R Nagasundara; Noor Shahina Begum

doi:10.1107/S1600536811000146

. 2011 Jan 12;67(Pt 2):o341–o342. doi: 10.1107/S1600536811000146

2-(4-Methylsulfanylphenyl)-1H-benzimidazol-3-ium bromide

Mohamed Ziaulla ^a, M N Manjunatha ^a, Ravish Sankolli ^b, K R Nagasundara ^a, Noor Shahina Begum ^a,^*

PMCID: PMC3051663 PMID: 21523024

Abstract

In the cation of the title compound, C₁₄H₁₃N₂S⁺·Br⁻, the essentially planar benzimidazole system (r.m.s. deviation = 0.0082 Å) is substituted with a 4-methylsulfanylphenyl ring. The dihedral angle between the benzimidazole system and the 4-methylsulfanylphenyl ring is 2.133 (2)°. The crystal structure is characterized by strong and highly directional intermolecular N—H⋯Br hydrogen bonds involving the bromide ion. Moreover, C—H⋯S interactions result in chains of molecules along the c axis. The supramolecular assembly is further stabilized by π–π stacking interactions between the benzimidazole system and 4-methylsulfanylphenyl rings [centroid–centroid distance = 3.477 (4) Å].

Related literature

For general background to benzimidazoles and their derivatives, see: Huang & Scarborough (1999 ▶); Preston (1974 ▶); Zarrinmayeh et al. (1998 ▶); Zhu et al. (2000 ▶). For related structures, see: Goker et al. (1995 ▶); Ozbey et al. (1998 ▶); Vasudevan et al. (1994 ▶). For hydrogen bonding, see: Bernstein et al. (1995 ▶); Nardelli (1983 ▶).

Experimental

Crystal data

C₁₄H₁₃N₂S⁺·Br⁻
M _r = 321.23
Monoclinic,
a = 5.3289 (2) Å
b = 24.0195 (12) Å
c = 10.9544 (5) Å
β = 100.113 (2)°
V = 1380.35 (11) Å³
Z = 4
Mo Kα radiation
μ = 3.11 mm⁻¹
T = 296 K
0.20 × 0.18 × 0.16 mm

Data collection

Bruker SMART APEX CCD detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T _min = 0.575, T _max = 0.636
23823 measured reflections
3009 independent reflections
2273 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.069
S = 1.03
3009 reflections
215 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.29 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 (Farrugia, 1997 ▶) and CAMERON (Watkin et al., 1996) ▶; software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811000146/pb2053sup1.cif

e-67-0o341-sup1.cif^{(17.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811000146/pb2053Isup2.hkl

e-67-0o341-Isup2.hkl^{(144.7KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯Br1	0.74 (2)	2.51 (2)	3.247 (2)	171 (2)
N2—H2N⋯Br1ⁱ	0.77 (3)	2.50 (2)	3.231 (2)	159
C5—H5⋯S1ⁱⁱ	0.97 (3)	2.98 (3)	3.736 (3)	135

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

Acknowledgments

NSB is thankful to the University Grants Commission (UGC), India, for financial assistance and the Department of Science and Technology (DST), India, for the data collection facility under the IRHPA–DST program. MNM thanks the M. S. Ramaiah Institute of Technology, Bangalore, for their support and encouragement.

supplementary crystallographic information

Comment

Benzimidazoles and their derivatives exhibit a number of important pharmacological properties, such as antihistaminic, anti-ulcerative, antiallergic, and antipyretic. In addition, benzimidazole derivatives are effective against the human cytomegalo virus (HCMV) (Zhu et al., 2000) and are also efficient selective neuropeptide Y Y1 receptor antagonists (Zarrinmayeh et al., 1998). Most of the described methods for the synthesisof benzimidazoles make use of volatile organic solvents and involve solid-phase synthesis via o-nitroanilines (Preston et al., 1974; Huang et al., 1999) or the condensation of o-phenylenediamines with carboxylic acid derivatives, aldehydes and aryl halides. In the title compound, there is one benzimidazole thiomethyl phenyl cation and one Br^- anion in the asymmetric unit. The expected proton transfer from HBr to benzimidazole thiomethyl phenyl occurs at atom N1 of the benzimidazole ring. Consequently,atom N1 shows quaternary character and bears a positive charge. In the molecule, the benzimidazole and thiomethyl phenyl rings are planar inclined at an dihedral angle 2.133 (2)° between them. The molecular structure is primarily stabilized by strong intramolecular N—H···Br hydrogen bond. The bond lengths and angles for the benzimidazole moiety of the molecule are in good agreement, within experimental errors, with those observed in other benzimidazole derivatives (Goker et al., 1995; Ozbey et al., 1998; Vasudevan et al.,1994).Further, the crystal structure is stabilized by intermolecular interactions into three dimensional framework structure by the combination of C—H···S and N—H···Br. The C—H···S and N—H···Br interactions together generates tetramers linking the molecules into chain like pattern along crystallographic c-axis. Additionally,the supramolecular assembly is further stabilized by π-π-stacking interactions between the benzimidazole and thiomethyl phenyl rings. The C3—C10 (x, 0.5 - y, 1/2 + z) disposed at a distance of 3.477 (4) Å.

Experimental

A ethanol solution (20 ml) of zinc bromide (2.25 mg, 1.0 mmol) was treated with 2-(p-thiomethylphenyl)benzimidazole (4.80 mg, 2.0 mmol) in ethanol (20 ml). The mixture was then treated with 48% HBr (2–3 ml) followed by liquid Br2 (2–3 ml). The mixture was refluxed for 6 hrs on a steam bath filtered and allowed to stand at room temperature for two days. Coloured crystals separated and these were washed with ethanol and dried. (yield 4.00 mg; 83%).