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Journal logoIUCrDATA
ISSN: 2414-3146

Ethyl 2-(4-meth­­oxy­phen­yl)-1-methyl-1H-benzimidazole-5-carboxyl­ate

CROSSMARK_Color_square_no_text.svg

aInstitution of Excellence, University of Mysore, Manasagangotri, Mysuru 570 006, India, bPG Department of Chemistry, SDM College (Autonomous), Ujire 574 240, India, cDepartment of Chemistry, Mangalore University, Mangaluru 574 199, India, dDepartment of Chemistry, Science College, An-Najah National University, PO Box 7, Nablus, West Bank, Palestinian Territories, and eDepartment of Studies in Physics, University of Mysore, Manasagangotri, Mysuru 570 006, India
*Correspondence e-mail: lokanath@physics.uni-mysore.ac.in, khalil.i@najah.edu

Edited by D.-J. Xu, Zhejiang University (Yuquan Campus), China (Received 17 March 2017; accepted 20 March 2017; online 24 March 2017)

In the title benzimidazole derivative, C18H18N2O3, the meth­oxy­phenyl ring is twisted with respect to the benzimidazole ring system, making a dihedral angle of 28.81 (5)°. The pendant ethyl chain has an extended conformation. Within the imidazole ring, the C—N single bonds have a partial double-bond character. In the crystal, mol­ecules are linked by weak C—H⋯π inter­actions and ππ stacking [the centroid-to-centroid distances being 3.6468 (7), 3.7279 (7) and 3.7481 (7) Å].

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Benzimidazole and its derivatives are found to exhibit various biological activities such as anti­microbial (Göker et al., 2002[Göker, H., Kuş, C., Boykin, D. W., Yildiz, S. & Altanlar, N. (2002). Bioorg. Med. Chem. 10, 2589-2596.]), anti-inflammatory, anti­allergic, anti­oxidant, anti­tubercular, anti­cancer, anthelmintic, anti­viral and anti­malarial. As part of ongoing research on benzimidazoles (Naveen et al., 2016a[Naveen, S., Kumar, V., Poojary, B., Shivarama Holla, B., Lokanath, N. K. & Abdoh, M. M. M. (2016a). IUCrData, 1, x161759.],b[Naveen, S., Kumar, V., Poojary, B., Vishwanatha, P., Lokanath, N. K. & Abdoh, M. M. M. (2016b). IUCrData, 1, x161744.]; Saberi et al., 2009[Saberi, A., Manjunath, H. R., Naveen, S., Prasad, T. N. M., Rangappa, K. S., Sridhar, M. A. & Prasad, J. S. (2009). Mol. Cryst. Liq. Cryst. 515, 199-206.]), we report herein on the synthesis and crystal structure of the title compound.

The title mol­ecule, Fig. 1[link], is non-planar with the meth­oxy­phenyl and the benzimidazole ring system inclined at an angle of 28.81 (5)°. The pendant ethyl chain has an extended conformation, as indicated by the C5—C16—O2—C17 torsion angle of −172.79 (10)°. The imidazole ring is planar, with a maximum deviation of 0.0163 (12) Å for the atom C7. The formal single bonds C1—N1 = 1.3839 (15) Å and C2—N1 = 1.3797 (15) Å have a partial double-bond character, and are significantly shorter than the Csp2—N bond distance. The meth­oxy group lies in the plane of the phenyl ring, as indicated by the C15—O1—C12—C13 torsion angle of −2.36 (18)°.

[Figure 1]
Figure 1
A view of the mol­ecular structure of the title compound, with the atom-numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.

In the crystal, the mol­ecules are linked by weak C—H⋯π (Table 1[link]) and ππ stacking [centroid-to-centroid distances = 3.6468 (7), 3.7279 (7) and 3.7481 (7) Å] inter­actions.

Table 1
Hydrogen-bond geometry (Å, °)

Cg3 is the centroid of the C9–C14 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
C14—H14⋯Cg3i 0.93 2.81 3.4950 (13) 132
Symmetry code: (i) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, z].

Synthesis and crystallization

Sodium di­thio­nite (3.0 eq) was added to a stirred solution of ethyl 3-nitro-4-(propyl­amino)­benzoate (3.9 mmol) and 4-meth­oxy benzaldehyde (3.9 mmol) in DMSO (15 ml). The reaction mixture was stirred at 363 K for 3 h. After the completion of reaction [monitored by TLC hexa­ne: ethyl acetate (7: 3, v/v)], it was poured onto crushed ice. The solid separated was filtered off, washed with water and dried. The product was recrystallized using di­methyl­formamide to get prismatic brown crystals. Yield 85%, m.p. 507 K.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C18H18N2O3
Mr 310.34
Crystal system, space group Orthorhombic, Pbcn
Temperature (K) 296
a, b, c (Å) 13.5151 (3), 7.3929 (2), 30.6704 (8)
V3) 3064.46 (13)
Z 8
Radiation type Cu Kα
μ (mm−1) 0.75
Crystal size (mm) 0.27 × 0.24 × 0.22
 
Data collection
Diffractometer Bruker X8 Proteum
Absorption correction Multi-scan (SADABS; Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.822, 0.852
No. of measured, independent and observed [I > 2σ(I)] reflections 10668, 2510, 2422
Rint 0.026
(sin θ/λ)max−1) 0.585
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.090, 1.04
No. of reflections 2510
No. of parameters 212
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.16, −0.15
Computer programs: APEX2 and SAINT (Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 and SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]).

Structural data


Computing details top

Data collection: APEX2 (Bruker, 2013); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: Mercury (Macrae et al., 2008).

Ethyl 2-(4-methoxyphenyl)-1-methyl-1H-benzimidazole-5-carboxylate top
Crystal data top
C18H18N2O3F(000) = 1312
Mr = 310.34Dx = 1.345 Mg m3
Orthorhombic, PbcnCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2n 2abCell parameters from 2422 reflections
a = 13.5151 (3) Åθ = 6.6–64.4°
b = 7.3929 (2) ŵ = 0.75 mm1
c = 30.6704 (8) ÅT = 296 K
V = 3064.46 (13) Å3Prism, brown
Z = 80.27 × 0.24 × 0.22 mm
Data collection top
Bruker X8 Proteum
diffractometer
2510 independent reflections
Radiation source: Bruker MicroStar microfocus rotating anode2422 reflections with I > 2σ(I)
Helios multilayer optics monochromatorRint = 0.026
Detector resolution: 18.4 pixels mm-1θmax = 64.4°, θmin = 6.6°
φ and ω scansh = 1514
Absorption correction: multi-scan
(SADABS; Bruker, 2013)
k = 85
Tmin = 0.822, Tmax = 0.852l = 3528
10668 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034H-atom parameters constrained
wR(F2) = 0.090 w = 1/[σ2(Fo2) + (0.048P)2 + 1.1189P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.001
2510 reflectionsΔρmax = 0.16 e Å3
212 parametersΔρmin = 0.15 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), FC*=KFC[1+0.001XFC2Λ3/SIN(2Θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0031 (4)
Special details top

Experimental. M.p.: 234 °C; IR (KBr, γmax, cm-1): 3040 (=C-H), 2953 (C-H), 1713 (C=O), 1616 (C=N), 1538 (C=C), 1296 (C-O); 1H NMR (400 MHz, DMSO-d6, δ ppm): 8.53 (s,1H, benzimidazole-H4), 8.02-8.00 (dd, 1H, 8Hz and 2Hz, benzimidazole-H6), 7.65-7.63 (dd, 2H, J = 8 Hz and 2 Hz, 4-methoxyphenyl-H), 7.40 (d, 1H, J = 8 Hz, benzimidazole-H7), 7.04 (d, 2H, J = 8 Hz, 4-methoxyphenyl-H), 4.46-4.40 (q, 2H, J = 7.5 Hz, CH2), 4.03 (s, 3H, CH3), 3.84 (s, 3H, OCH3), 1.32 (t, 3H, J = 7.5 Hz, CH3); MS (m/z): 311.4 (M+1); Anal. calcd. For C18H18N2O3: C, 69.66; H, 5.85; N, 9.03; Found: C, 69.68; H, 5.87; N, 9.06.

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > 2sigma(F2) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.08135 (7)0.56378 (13)0.71043 (3)0.0312 (3)
O20.11642 (7)0.08394 (12)0.35399 (3)0.0268 (3)
O30.27489 (7)0.06640 (14)0.33238 (3)0.0355 (3)
N10.30071 (7)0.35550 (13)0.52717 (3)0.0216 (3)
N20.13886 (7)0.32053 (14)0.51133 (3)0.0223 (3)
C10.20388 (9)0.36488 (16)0.54167 (4)0.0209 (3)
C20.29650 (9)0.29805 (15)0.48441 (4)0.0212 (3)
C30.37076 (9)0.26025 (16)0.45417 (4)0.0238 (4)
C40.33989 (9)0.20238 (16)0.41371 (4)0.0237 (3)
C50.23893 (9)0.18021 (16)0.40344 (4)0.0223 (3)
C60.16582 (9)0.21861 (16)0.43400 (4)0.0220 (3)
C70.19542 (9)0.27813 (15)0.47489 (4)0.0205 (3)
C80.39114 (9)0.41890 (17)0.54821 (4)0.0257 (4)
C90.17570 (9)0.41237 (16)0.58652 (4)0.0212 (3)
C100.08255 (9)0.48988 (16)0.59397 (4)0.0215 (3)
C110.05289 (9)0.53785 (17)0.63549 (4)0.0233 (3)
C120.11594 (9)0.50725 (17)0.67093 (4)0.0231 (3)
C130.20661 (9)0.42354 (17)0.66442 (4)0.0244 (3)
C140.23554 (9)0.37614 (17)0.62252 (4)0.0240 (3)
C150.14151 (11)0.5281 (2)0.74794 (4)0.0339 (4)
C160.21437 (9)0.10645 (17)0.35984 (4)0.0244 (4)
C170.08742 (11)0.0079 (2)0.31430 (4)0.0318 (4)
C180.02236 (11)0.0354 (2)0.31644 (5)0.0375 (5)
H30.437400.273400.460900.0290*
H40.387100.177200.392500.0280*
H60.099200.204800.427200.0260*
H8A0.421900.320300.563400.0390*
H8B0.375300.513300.568500.0390*
H8C0.435700.464900.526500.0390*
H100.040100.509300.570600.0260*
H110.008800.590400.639900.0280*
H130.247800.399300.688000.0290*
H140.296100.319000.618400.0290*
H15A0.152600.400200.750400.0510*
H15B0.108400.571000.773600.0510*
H15C0.203800.589100.744900.0510*
H17A0.121000.123400.312000.0380*
H17B0.104600.064700.289100.0380*
H18A0.038700.101300.342400.0560*
H18B0.043800.102500.291400.0560*
H18C0.054900.080100.316900.0560*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0268 (5)0.0484 (6)0.0183 (5)0.0074 (4)0.0001 (4)0.0012 (4)
O20.0244 (5)0.0332 (5)0.0229 (5)0.0015 (4)0.0008 (4)0.0036 (4)
O30.0303 (5)0.0497 (6)0.0266 (5)0.0012 (4)0.0074 (4)0.0084 (4)
N10.0196 (5)0.0229 (5)0.0223 (5)0.0013 (4)0.0006 (4)0.0002 (4)
N20.0204 (5)0.0251 (5)0.0215 (5)0.0004 (4)0.0020 (4)0.0002 (4)
C10.0198 (6)0.0193 (6)0.0236 (6)0.0005 (5)0.0012 (5)0.0019 (5)
C20.0221 (6)0.0187 (6)0.0227 (6)0.0004 (5)0.0012 (5)0.0017 (5)
C30.0178 (6)0.0248 (6)0.0288 (7)0.0002 (5)0.0025 (5)0.0006 (5)
C40.0212 (6)0.0238 (6)0.0261 (6)0.0015 (5)0.0058 (5)0.0006 (5)
C50.0226 (6)0.0213 (6)0.0230 (6)0.0014 (5)0.0025 (5)0.0017 (5)
C60.0184 (6)0.0231 (6)0.0244 (6)0.0008 (5)0.0010 (5)0.0020 (5)
C70.0191 (6)0.0202 (6)0.0222 (6)0.0010 (5)0.0032 (5)0.0018 (5)
C80.0207 (6)0.0275 (7)0.0290 (7)0.0036 (5)0.0024 (5)0.0022 (5)
C90.0220 (6)0.0191 (6)0.0224 (6)0.0027 (5)0.0010 (5)0.0014 (5)
C100.0205 (6)0.0224 (6)0.0217 (6)0.0022 (5)0.0020 (5)0.0012 (5)
C110.0189 (6)0.0261 (6)0.0250 (6)0.0006 (5)0.0013 (5)0.0006 (5)
C120.0229 (6)0.0264 (6)0.0201 (6)0.0028 (5)0.0019 (5)0.0010 (5)
C130.0226 (6)0.0281 (6)0.0225 (6)0.0007 (5)0.0021 (5)0.0044 (5)
C140.0210 (6)0.0254 (6)0.0256 (6)0.0024 (5)0.0013 (5)0.0029 (5)
C150.0308 (7)0.0510 (8)0.0200 (6)0.0031 (7)0.0026 (5)0.0003 (6)
C160.0247 (7)0.0254 (6)0.0231 (6)0.0013 (5)0.0035 (5)0.0022 (5)
C170.0354 (8)0.0367 (7)0.0233 (7)0.0006 (6)0.0031 (6)0.0048 (6)
C180.0356 (8)0.0425 (8)0.0344 (8)0.0056 (6)0.0051 (6)0.0054 (6)
Geometric parameters (Å, º) top
O1—C121.3641 (15)C12—C131.3873 (17)
O1—C151.4332 (16)C13—C141.3882 (17)
O2—C161.3462 (15)C17—C181.499 (2)
O2—C171.4479 (16)C3—H30.9300
O3—C161.2108 (15)C4—H40.9300
N1—C11.3839 (15)C6—H60.9300
N1—C21.3797 (15)C8—H8A0.9600
N1—C81.4594 (15)C8—H8B0.9600
N2—C11.3212 (15)C8—H8C0.9600
N2—C71.3899 (15)C10—H100.9300
C1—C91.4699 (17)C11—H110.9300
C2—C31.3948 (17)C13—H130.9300
C2—C71.4047 (17)C14—H140.9300
C3—C41.3773 (17)C15—H15A0.9600
C4—C51.4099 (17)C15—H15B0.9600
C5—C61.3912 (17)C15—H15C0.9600
C5—C161.4818 (17)C17—H17A0.9700
C6—C71.3880 (17)C17—H17B0.9700
C9—C101.4020 (17)C18—H18A0.9600
C9—C141.3946 (17)C18—H18B0.9600
C10—C111.3813 (17)C18—H18C0.9600
C11—C121.3996 (17)
C12—O1—C15117.52 (10)C4—C3—H3122.00
C16—O2—C17115.86 (10)C3—C4—H4119.00
C1—N1—C2106.37 (9)C5—C4—H4119.00
C1—N1—C8129.33 (10)C5—C6—H6121.00
C2—N1—C8123.62 (10)C7—C6—H6121.00
C1—N2—C7104.86 (10)N1—C8—H8A109.00
N1—C1—N2112.97 (10)N1—C8—H8B109.00
N1—C1—C9123.90 (11)N1—C8—H8C109.00
N2—C1—C9123.10 (11)H8A—C8—H8B110.00
N1—C2—C3131.61 (11)H8A—C8—H8C110.00
N1—C2—C7105.66 (10)H8B—C8—H8C109.00
C3—C2—C7122.72 (11)C9—C10—H10119.00
C2—C3—C4116.32 (11)C11—C10—H10119.00
C3—C4—C5122.04 (11)C10—C11—H11120.00
C4—C5—C6120.87 (11)C12—C11—H11120.00
C4—C5—C16117.46 (11)C12—C13—H13120.00
C6—C5—C16121.60 (11)C14—C13—H13120.00
C5—C6—C7117.95 (11)C9—C14—H14119.00
N2—C7—C2110.13 (10)C13—C14—H14119.00
N2—C7—C6129.76 (11)O1—C15—H15A109.00
C2—C7—C6120.09 (11)O1—C15—H15B109.00
C1—C9—C10118.87 (11)O1—C15—H15C109.00
C1—C9—C14123.01 (11)H15A—C15—H15B110.00
C10—C9—C14118.05 (11)H15A—C15—H15C109.00
C9—C10—C11121.05 (11)H15B—C15—H15C109.00
C10—C11—C12119.85 (11)O2—C17—H17A110.00
O1—C12—C11115.57 (11)O2—C17—H17B110.00
O1—C12—C13124.56 (11)C18—C17—H17A110.00
C11—C12—C13119.88 (11)C18—C17—H17B110.00
C12—C13—C14119.65 (11)H17A—C17—H17B109.00
C9—C14—C13121.41 (11)C17—C18—H18A109.00
O2—C16—O3122.78 (11)C17—C18—H18B110.00
O2—C16—C5112.71 (10)C17—C18—H18C109.00
O3—C16—C5124.50 (11)H18A—C18—H18B109.00
O2—C17—C18107.14 (11)H18A—C18—H18C110.00
C2—C3—H3122.00H18B—C18—H18C109.00
C15—O1—C12—C11177.32 (11)N1—C2—C7—C6179.07 (10)
C15—O1—C12—C132.36 (18)C3—C2—C7—N2178.38 (11)
C17—O2—C16—O35.78 (18)C3—C2—C7—C60.00 (18)
C17—O2—C16—C5172.79 (10)C2—C3—C4—C50.76 (17)
C16—O2—C17—C18174.33 (11)C3—C4—C5—C60.82 (18)
C2—N1—C1—N20.92 (13)C3—C4—C5—C16176.30 (11)
C2—N1—C1—C9176.89 (11)C4—C5—C6—C70.41 (17)
C8—N1—C1—N2169.74 (11)C16—C5—C6—C7176.59 (11)
C8—N1—C1—C912.44 (19)C4—C5—C16—O2177.52 (10)
C1—N1—C2—C3178.03 (12)C4—C5—C16—O31.02 (19)
C1—N1—C2—C70.94 (12)C6—C5—C16—O20.42 (17)
C8—N1—C2—C310.64 (19)C6—C5—C16—O3178.11 (12)
C8—N1—C2—C7170.39 (10)C5—C6—C7—N2178.00 (11)
C7—N2—C1—N10.47 (13)C5—C6—C7—C20.00 (17)
C7—N2—C1—C9177.36 (11)C1—C9—C10—C11179.61 (11)
C1—N2—C7—C20.16 (13)C14—C9—C10—C113.36 (18)
C1—N2—C7—C6178.32 (12)C1—C9—C14—C13179.78 (12)
N1—C1—C9—C10153.90 (11)C10—C9—C14—C133.32 (18)
N1—C1—C9—C1429.23 (18)C9—C10—C11—C120.71 (19)
N2—C1—C9—C1028.51 (18)C10—C11—C12—O1178.21 (11)
N2—C1—C9—C14148.37 (12)C10—C11—C12—C132.09 (19)
N1—C2—C3—C4179.18 (12)O1—C12—C13—C14178.19 (12)
C7—C2—C3—C40.36 (17)C11—C12—C13—C142.14 (19)
N1—C2—C7—N20.70 (13)C12—C13—C14—C90.61 (19)
Hydrogen-bond geometry (Å, º) top
Cg3 is the centroid of the C9–C14 ring.
D—H···AD—HH···AD···AD—H···A
C14—H14···Cg3i0.932.813.4950 (13)132
Symmetry code: (i) x+1/2, y1/2, z.
 

Acknowledgements

The authors are grateful to the Institution of Excellence, Vijnana Bhavana, University of Mysore, India, for providing the single-crystal X-ray diffractometer facility.

References

First citationBruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGöker, H., Kuş, C., Boykin, D. W., Yildiz, S. & Altanlar, N. (2002). Bioorg. Med. Chem. 10, 2589–2596.  Web of Science CrossRef PubMed CAS Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationNaveen, S., Kumar, V., Poojary, B., Shivarama Holla, B., Lokanath, N. K. & Abdoh, M. M. M. (2016a). IUCrData, 1, x161759.  Google Scholar
First citationNaveen, S., Kumar, V., Poojary, B., Vishwanatha, P., Lokanath, N. K. & Abdoh, M. M. M. (2016b). IUCrData, 1, x161744.  Google Scholar
First citationSaberi, A., Manjunath, H. R., Naveen, S., Prasad, T. N. M., Rangappa, K. S., Sridhar, M. A. & Prasad, J. S. (2009). Mol. Cryst. Liq. Cryst. 515, 199–206.  Web of Science CSD CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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