Ethyl 1-phenyl-2-[4-(trifluoro­meth­yl)phen­yl]-1H-benzimidazole-5-carboxyl­ate

Yeong Keng Yoon; Mohamed Ashraf Ali; Tan Soo Choon; Suhana Arshad; Ibrahim Abdul Razak

doi:10.1107/S1600536812022210

. 2012 May 23;68(Pt 6):o1864–o1865. doi: 10.1107/S1600536812022210

Ethyl 1-phenyl-2-[4-(trifluoromethyl)phenyl]-1H-benzimidazole-5-carboxylate

Yeong Keng Yoon ^a, Mohamed Ashraf Ali ^a, Tan Soo Choon ^a, Suhana Arshad ^b, Ibrahim Abdul Razak ^b,^*,^‡

PMCID: PMC3379430 PMID: 22719628

Abstract

The asymmetric unit of the title compound, C₂₃H₁₇F₃N₂O₂, contains two molecules. In one of the molecules, the phenyl and triflouromethyl-substituted benzene rings form dihedral angles of 52.05 (8) and 33.70 (8)°, respectively, with the benzimidazole ring system, while the dihedral angle between them is 58.24 (10)°. The corresponding values in the other molecule are 58.40 (8), 25.90 (8) and 60.83 (10)°, respectively. In the crystal, molecules are linked into chains along [100] by C—H⋯O and C—H⋯N hydrogen bonds. Aromatic π–π stacking interactions [centroid–centroid distance = 3.6700 (12) Å] also occur.

Related literature

For background to benzimidazole derivatives as drugs, see: Spasov et al. (1999 ▶); Grassmann et al. (2002 ▶); Demirayak et al. (2002 ▶); Evans et al. (1997 ▶). For related structures, see: Yoon et al. (2011 ▶); Kassim et al. (2012 ▶). For stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶). graphic file with name e-68-o1864-scheme1.jpg

Experimental

Crystal data

C₂₃H₁₇F₃N₂O₂
M _r = 410.39
Monoclinic,
a = 9.8548 (2) Å
b = 25.0714 (6) Å
c = 16.0566 (4) Å
β = 107.023 (1)°
V = 3793.35 (15) Å³
Z = 8
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 100 K
0.43 × 0.37 × 0.28 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.953, T _max = 0.969
36855 measured reflections
10921 independent reflections
5999 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.062
wR(F ²) = 0.142
S = 1.03
10921 reflections
543 parameters
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.35 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812022210/hb6782sup1.cif

e-68-o1864-sup1.cif^{(46.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812022210/hb6782Isup2.hkl

e-68-o1864-Isup2.hkl^{(534KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812022210/hb6782Isup3.cml

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
C22B—H22D⋯O2A	0.98	2.43	3.250 (3)	141
C17B—H17B⋯N1Bⁱ	0.95	2.62	3.524 (3)	159
C22A—H22A⋯O2Bⁱⁱ	0.98	2.43	3.250 (3)	141

Open in a new tab

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

Acknowledgments

The authors thank the Malaysian Government and Universiti Sains Malaysia (USM) for the Research University Grant Nos.1001/PFIZIK/811151 and 1001/PSK/8620012. The authors also wish to express their thanks to the Pharmacogenetic and Novel Therapeutic Research, Institute for Research in Molecular Medicine, Universiti Sains Malaysia. SA also thanks the Malaysian government and USM for an Academic Staff Training Scheme (ASTS) fellowship.

supplementary crystallographic information

Comment

The benzimidazole nucleus is an important pharmacophore in drug discovery (Spasov et al., 1999). They thus generate a lot of pharmacological interests (Grassmann et al., 2002; Demirayak et al., 2002; Evans et al., 1997). As part of our studies in this area, the crystal structure determination of the title compound was carried out and the results are presented here.

The asymmetric unit of the title compound (Fig 1), consists of two crystallographically independent molecules A and B. The benzimidazole ring system in both molecules, N1A/N2A/C1A—C7A and N1B/N2B/C1B—C7B, are essentially planar with a maximum deviation of 0.014 (2) Å at atom C7A and of 0.006 (2) Å at atom N2B, respectively. In molecule A, the benzimidazole ring (N1A/N2A/C1A—C7A) makes dihedral angles of 52.05 (8) and 33.70 (8)°, respectively with the phenyl ring (C14A–C19A) and the triflouromethyl-substituted phenyl ring (C8A–C13A). The corresponding dihedral angles in molecule B are 58.40 (8) and 25.90 (8)°.

In addition, the phenyl ring and the triflouromethyl-substituted phenyl ring form dihedral angles of 58.24 (10) and 60.83 (10)° in molecule A and B, respectively. Bond lengths and angles are within normal ranges and are comparable to related structure (Yoon et al., 2011; Kassim et al., 2012).

In the crystal (Fig. 2), C22B—H22D···O2A, C17B—H17B···N1B and C22A—H22A···O2B (Table 1) hydrogen bonds link the molecules into one-dimensional chains along a-axis. π–π interactions of Cg1···Cg2 = 3.6700 (12) Å (symmetry code: 1 - x,1 - y,2 - z) further stabilized the structure [Cg1 and Cg2 are the centroids of the N1A/N2A/C1A/C7A/C8A and C1B–C6B rings, respectively].

Experimental

Ethyl 3-amino-4-(phenyl amino) benzoate (0.84 mmol) and sodium metabisulfite adduct of trifluoromethyl benzaldehyde (1.68 mmol) were dissolved in DMF. The reaction mixture was reflux at 130 °C for 2 h. After completion, the reaction mixture was diluted in ethyl acetate (20 ml) and washed with water (20 ml). The organic layer was collected, dried over Na₂SO₄ and the evaporated in vacuo to yield the product. The product was recrystallized from ethyl acetate as colourless blocks.