Ethyl 2-(2-methyl-1H-benzimidazol-1-yl)acetate

Xu, G.-H.; Wang, W.

doi:10.1107/S160053680802672X

organic compounds

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ISSN: 2056-9890

Volume 64| Part 9| September 2008| Page o1811

doi:10.1107/S160053680802672X

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Ethyl 2-(2-methyl-1H-benzimidazol-1-yl)acetate

Guang-Hai Xu ^a and Wei Wang ^a ^*

^aOrdered Matter Science Research Center, Southeast University, Nanjing 210096, People's Republic of China
^*Correspondence e-mail: seuwangwei@gmail.com

(Received 17 August 2008; accepted 19 August 2008; online 23 August 2008)

A new benzimidazole compound, C₁₂H₁₄N₂O₂, has been synthesized by the reaction of 2-methyl-1H-benzimidazole and ethyl 2-bromoacetate. In the crystal structure, weak intermolecular C—H⋯N hydrogen bonds link the molecules into chains. π⋯π Contacts (centroid⋯centroid distance = 3.713 Å) are observed. A C—H⋯π interaction is also present. The N—C—C—O torsion angle is 178.4 (2)°.

Related literature

For related literature, see: Aaker et al. (2005 ).

Experimental

Crystal data

C₁₂H₁₄N₂O₂
M_r = 218.25
Monoclinic, P n
a = 10.854 (2) Å
b = 4.7959 (10) Å
c = 11.842 (2) Å
β = 111.42 (3)°
V = 573.9 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 295 (2) K
0.2 × 0.1 × 0.1 mm

Data collection

Rigaku SCXmini diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ) T_min = 0.990, T_max = 1.000 (expected range = 0.981–0.991)
5696 measured reflections
1323 independent reflections
1085 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.041
wR(F²) = 0.089
S = 1.12
1323 reflections
145 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.10 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9B⋯N1ⁱ	0.97	2.61	3.532 (3)	159
C8—H8C⋯Cg1ⁱⁱ	0.97	2.74	3.633 (5)	155
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y, z+{\script{1\over 2}}]$ ; (ii) x, y-1, z. Cg1 is the centroid of the imidazole ring.

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S160053680802672X/wn2276sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053680802672X/wn2276Isup2.hkl

checkCIF report

Comment top

The molecular structure of the title compound is shown in Fig. 1. The benzimidazole system is essentially planar, with a dihedral angle of 0.88 (14)° between the planes of the benzene and imidazole rings. The N2—C9—C10—O2 torsion angle is 178.4 (2)°.

In the crystal structure, molecules are connected by weak intermolecular C—H···N hydrogen bonds, forming a polymeric chain (see Table 1 and Fig. 2). A C—H···π contact (see Table 1, Cg1 is the centroid of the imidazole ring) and π···π stacking (centroid···centroid distance = 3.713 Å) between neighboring benzimidazoles further stabilize the structure.

Related literature top

For related literature, see: Aaker et al. (2005). Cg1 is the centroid of the imidazole ring.

Experimental top

The synthesis of 2-methyl-1H-benzimidazole was reported previously (Aaker et al., 2005). Ethyl 2-bromoacetate (1.65 g, 10 mmol) was added to a solution of 2-methyl-1H-benzimidazole (1.32 g, 10 mmol) and NaH (0.6 g, 26 mmol) in THF (30 ml). After the mixture was stirred for 12 h at room temperature, the precipitate was filtered off and the solution was evaporated in vacuum. The crude product was then crystallized from ethanol. Single crystals suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution.

Computing details top

Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound, with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A view of the packing of the title compound, with pi···pi stacking along the b axis. Dashed lines indicate hydrogen bonds.

(I) top

Crystal data top

C₁₂H₁₄N₂O₂	F(000) = 232
M_r = 218.25	D_x = 1.263 Mg m⁻³
Monoclinic, Pn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2yac	Cell parameters from 6060 reflections
a = 10.854 (2) Å	θ = 6.4–55.1°
b = 4.7959 (10) Å	µ = 0.09 mm⁻¹
c = 11.842 (2) Å	T = 295 K
β = 111.42 (3)°	Prism, colorless
V = 573.9 (2) Å³	0.2 × 0.1 × 0.1 mm
Z = 2

Data collection top

Rigaku SCXmini diffractometer	1323 independent reflections
Radiation source: fine-focus sealed tube	1085 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
Detector resolution: 13.6612 pixels mm^-1	θ_max = 27.5°, θ_min = 3.2°
CCD_Profile_fitting scans	h = −14→14
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −6→6
T_min = 0.990, T_max = 1.000	l = −15→15
5696 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.090	H-atom parameters constrained
S = 1.12	w = 1/[σ²(F_o²) + (0.0435P)² + 0.018P] where P = (F_o² + 2F_c²)/3
1323 reflections	(Δ/σ)_max < 0.001
145 parameters	Δρ_max = 0.10 e Å⁻³
2 restraints	Δρ_min = −0.15 e Å⁻³

Crystal data top

C₁₂H₁₄N₂O₂	V = 573.9 (2) Å³
M_r = 218.25	Z = 2
Monoclinic, Pn	Mo Kα radiation
a = 10.854 (2) Å	µ = 0.09 mm⁻¹
b = 4.7959 (10) Å	T = 295 K
c = 11.842 (2) Å	0.2 × 0.1 × 0.1 mm
β = 111.42 (3)°

Data collection top

Rigaku SCXmini diffractometer	1323 independent reflections
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	1085 reflections with I > 2σ(I)
T_min = 0.990, T_max = 1.000	R_int = 0.033
5696 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.041	2 restraints
wR(F²) = 0.090	H-atom parameters constrained
S = 1.12	Δρ_max = 0.10 e Å⁻³
1323 reflections	Δρ_min = −0.15 e Å⁻³
145 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) 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

	x	y	z	U_iso*/U_eq
O2	0.14135 (17)	0.1457 (4)	0.20123 (14)	0.0515 (5)
C5	0.1006 (3)	−0.1654 (5)	−0.2701 (2)	0.0449 (6)
C1	0.3029 (2)	−0.2567 (6)	−0.0948 (2)	0.0471 (6)
H1A	0.3572	−0.2219	−0.0148	0.056*
N2	0.12080 (19)	0.0836 (4)	−0.10788 (17)	0.0412 (5)
C10	0.1019 (2)	0.0363 (5)	0.0906 (2)	0.0413 (5)
C9	0.1639 (2)	0.1907 (6)	0.0146 (2)	0.0425 (6)
H9A	0.1409	0.3867	0.0121	0.051*
H9B	0.2594	0.1753	0.0518	0.051*
N1	−0.0107 (2)	0.0004 (5)	−0.30007 (18)	0.0497 (6)
O1	0.0293 (2)	−0.1587 (4)	0.05777 (18)	0.0685 (6)
C4	0.1383 (3)	−0.3615 (6)	−0.3381 (2)	0.0576 (8)
H4A	0.0850	−0.3960	−0.4184	0.069*
C6	0.1845 (2)	−0.1163 (5)	−0.1499 (2)	0.0390 (6)
C7	0.0038 (2)	0.1447 (5)	−0.2017 (2)	0.0454 (6)
C2	0.3361 (3)	−0.4510 (7)	−0.1649 (2)	0.0540 (7)
H2A	0.4147	−0.5501	−0.1311	0.065*
C3	0.2550 (3)	−0.5027 (7)	−0.2850 (3)	0.0596 (7)
H3A	0.2805	−0.6350	−0.3296	0.072*
C12	0.1640 (3)	0.1400 (8)	0.4080 (3)	0.0737 (10)
H12A	0.1322	0.0602	0.4666	0.111*
H12B	0.1510	0.3383	0.4051	0.111*
H12C	0.2565	0.0999	0.4306	0.111*
C8	−0.0919 (3)	0.3503 (6)	−0.1883 (3)	0.0598 (8)
H8A	−0.1666	0.3635	−0.2632	0.090*
H8B	−0.0500	0.5293	−0.1683	0.090*
H8C	−0.1212	0.2914	−0.1248	0.090*
C11	0.0894 (3)	0.0179 (7)	0.2857 (3)	0.0617 (8)
H11A	0.1016	−0.1826	0.2873	0.074*
H11B	−0.0044	0.0568	0.2617	0.074*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O2	0.0623 (12)	0.0550 (11)	0.0392 (10)	−0.0084 (9)	0.0209 (9)	−0.0061 (8)
C5	0.0512 (15)	0.0505 (15)	0.0271 (11)	−0.0146 (12)	0.0075 (11)	0.0011 (11)
C1	0.0448 (14)	0.0577 (16)	0.0327 (12)	−0.0087 (12)	0.0070 (10)	−0.0014 (12)
N2	0.0423 (11)	0.0447 (12)	0.0312 (10)	−0.0065 (9)	0.0069 (8)	−0.0003 (9)
C10	0.0419 (13)	0.0418 (13)	0.0383 (13)	0.0019 (11)	0.0126 (10)	−0.0012 (11)
C9	0.0452 (14)	0.0437 (15)	0.0345 (12)	−0.0095 (11)	0.0095 (10)	−0.0074 (10)
N1	0.0493 (12)	0.0502 (13)	0.0363 (12)	−0.0092 (11)	0.0000 (9)	0.0043 (10)
O1	0.0865 (15)	0.0659 (14)	0.0564 (12)	−0.0334 (12)	0.0301 (11)	−0.0148 (10)
C4	0.0744 (19)	0.0620 (18)	0.0291 (13)	−0.0186 (16)	0.0102 (13)	−0.0110 (13)
C6	0.0432 (13)	0.0434 (14)	0.0283 (12)	−0.0123 (11)	0.0104 (10)	0.0010 (10)
C7	0.0426 (14)	0.0450 (14)	0.0395 (14)	−0.0087 (12)	0.0041 (11)	0.0077 (11)
C2	0.0499 (15)	0.0627 (19)	0.0483 (17)	0.0003 (14)	0.0166 (13)	−0.0013 (14)
C3	0.0726 (19)	0.0613 (18)	0.0468 (17)	−0.0082 (15)	0.0242 (15)	−0.0129 (14)
C12	0.083 (2)	0.095 (3)	0.0472 (17)	0.0068 (19)	0.0283 (16)	0.0017 (17)
C8	0.0515 (16)	0.0546 (16)	0.0659 (19)	0.0001 (14)	0.0127 (14)	0.0089 (14)
C11	0.0716 (19)	0.073 (2)	0.0508 (18)	−0.0011 (16)	0.0346 (15)	−0.0009 (15)

Geometric parameters (Å, º) top

O2—C10	1.329 (3)	C4—C3	1.370 (5)
O2—C11	1.451 (3)	C4—H4A	0.9300
C5—N1	1.380 (4)	C7—C8	1.482 (4)
C5—C4	1.393 (4)	C2—C3	1.395 (4)
C5—C6	1.401 (3)	C2—H2A	0.9300
C1—C2	1.380 (4)	C3—H3A	0.9300
C1—C6	1.385 (4)	C12—C11	1.497 (4)
C1—H1A	0.9300	C12—H12A	0.9600
N2—C6	1.376 (3)	C12—H12B	0.9600
N2—C7	1.379 (3)	C12—H12C	0.9600
N2—C9	1.446 (3)	C8—H8A	0.9600
C10—O1	1.193 (3)	C8—H8B	0.9600
C10—C9	1.502 (3)	C8—H8C	0.9600
C9—H9A	0.9700	C11—H11A	0.9700
C9—H9B	0.9700	C11—H11B	0.9700
N1—C7	1.315 (3)

C10—O2—C11	116.5 (2)	N1—C7—C8	125.7 (2)
N1—C5—C4	130.8 (2)	N2—C7—C8	122.1 (2)
N1—C5—C6	110.3 (2)	C1—C2—C3	121.8 (3)
C4—C5—C6	118.8 (3)	C1—C2—H2A	119.1
C2—C1—C6	116.5 (2)	C3—C2—H2A	119.1
C2—C1—H1A	121.7	C4—C3—C2	120.9 (3)
C6—C1—H1A	121.7	C4—C3—H3A	119.5
C6—N2—C7	107.06 (19)	C2—C3—H3A	119.5
C6—N2—C9	126.07 (19)	C11—C12—H12A	109.5
C7—N2—C9	126.7 (2)	C11—C12—H12B	109.5
O1—C10—O2	124.6 (2)	H12A—C12—H12B	109.5
O1—C10—C9	125.3 (2)	C11—C12—H12C	109.5
O2—C10—C9	110.04 (19)	H12A—C12—H12C	109.5
N2—C9—C10	112.00 (19)	H12B—C12—H12C	109.5
N2—C9—H9A	109.2	C7—C8—H8A	109.5
C10—C9—H9A	109.2	C7—C8—H8B	109.5
N2—C9—H9B	109.2	H8A—C8—H8B	109.5
C10—C9—H9B	109.2	C7—C8—H8C	109.5
H9A—C9—H9B	107.9	H8A—C8—H8C	109.5
C7—N1—C5	105.4 (2)	H8B—C8—H8C	109.5
C3—C4—C5	119.0 (3)	O2—C11—C12	107.0 (3)
C3—C4—H4A	120.5	O2—C11—H11A	110.3
C5—C4—H4A	120.5	C12—C11—H11A	110.3
N2—C6—C1	132.1 (2)	O2—C11—H11B	110.3
N2—C6—C5	105.0 (2)	C12—C11—H11B	110.3
C1—C6—C5	122.9 (2)	H11A—C11—H11B	108.6
N1—C7—N2	112.2 (2)

C11—O2—C10—O1	−1.1 (4)	C2—C1—C6—C5	0.2 (3)
C11—O2—C10—C9	180.0 (2)	N1—C5—C6—N2	0.1 (3)
C6—N2—C9—C10	−93.6 (3)	C4—C5—C6—N2	−179.8 (2)
C7—N2—C9—C10	80.8 (3)	N1—C5—C6—C1	179.1 (2)
O1—C10—C9—N2	2.6 (4)	C4—C5—C6—C1	−0.8 (4)
O2—C10—C9—N2	−178.4 (2)	C5—N1—C7—N2	0.6 (3)
C4—C5—N1—C7	179.5 (3)	C5—N1—C7—C8	−179.1 (2)
C6—C5—N1—C7	−0.4 (3)	C6—N2—C7—N1	−0.6 (3)
N1—C5—C4—C3	−179.0 (3)	C9—N2—C7—N1	−175.9 (2)
C6—C5—C4—C3	0.9 (4)	C6—N2—C7—C8	179.1 (2)
C7—N2—C6—C1	−178.6 (3)	C9—N2—C7—C8	3.9 (4)
C9—N2—C6—C1	−3.3 (4)	C6—C1—C2—C3	0.2 (4)
C7—N2—C6—C5	0.3 (2)	C5—C4—C3—C2	−0.5 (4)
C9—N2—C6—C5	175.6 (2)	C1—C2—C3—C4	−0.1 (4)
C2—C1—C6—N2	179.0 (3)	C10—O2—C11—C12	170.5 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9B···N1ⁱ	0.97	2.61	3.532 (3)	159
C8—H8C···Cg1ⁱⁱ	0.97	2.74	3.633 (5)	155

Symmetry codes: (i) x+1/2, −y, z+1/2; (ii) x, y−1, z.

Experimental details

Crystal data
Chemical formula	C₁₂H₁₄N₂O₂
M_r	218.25
Crystal system, space group	Monoclinic, Pn
Temperature (K)	295
a, b, c (Å)	10.854 (2), 4.7959 (10), 11.842 (2)
β (°)	111.42 (3)
V (Å³)	573.9 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.2 × 0.1 × 0.1

Data collection
Diffractometer	Rigaku SCXmini diffractometer
Absorption correction	Multi-scan (CrystalClear; Rigaku, 2005)
T_min, T_max	0.990, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	5696, 1323, 1085
R_int	0.033
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.041, 0.090, 1.12
No. of reflections	1323
No. of parameters	145
No. of restraints	2
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.10, −0.15

Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9B···N1ⁱ	0.97	2.61	3.532 (3)	158.6
C8—H8C···Cg1ⁱⁱ	0.97	2.7415	3.633 (5)	154.8

Symmetry codes: (i) x+1/2, −y, z+1/2; (ii) x, y−1, z.

Acknowledgements

The authors are grateful to the Starter Fund of Southeast University for financial support to buy the X-ray diffractometer.

References

Aaker, C. B., Desper, J. & Urbinam, J. F. (2005). Cryst. Growth Des. 5, 1283–1293. Google Scholar
Rigaku (2005). CrystalClear. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar