1,3-Bis(1-methyl-1H-benzimidazol-2-yl)-2-oxapropane

Kou, F.; Liu, B.; Bai, Y.; Kong, J.; Wu, H.

doi:10.1107/S1600536811017922

organic compounds

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ISSN: 2056-9890

Volume 67| Part 6| June 2011| Page o1439

doi:10.1107/S1600536811017922

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1,3-Bis(1-methyl-1H-benzimidazol-2-yl)-2-oxapropane

Fan Kou,^a Bin Liu,^a Ying Bai,^a Jin Kong ^a and Huilu Wu ^a ^*

^aSchool of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou 730070, People's Republic of China
^*Correspondence e-mail: wuhuilu@163.com

(Received 3 May 2011; accepted 12 May 2011; online 20 May 2011)

In the title molecule, C₁₈H₁₈N₄O, the dihedral angle between the mean planes of the two benzimidazole ring systems is 61.5 (1)°.

Related literature

For biological applications of benzimidazoles and bis-benzimidazoles, see: Horton et al. (2003 ); Holland & Tolman (2000 ). For related structures, see: Chen et al. (2009 ); Wu et al. (2009 ).

Experimental

Crystal data

C₁₈H₁₈N₄O
M_r = 306.36
Monoclinic, P 2₁ /n
a = 6.634 (6) Å
b = 16.217 (15) Å
c = 14.457 (13) Å
β = 101.102 (10)°
V = 1526 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.26 × 0.24 × 0.21 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.978, T_max = 0.982
10239 measured reflections
2668 independent reflections
1846 reflections with I > 2σ(I)
R_int = 0.057

Refinement

R[F² > 2σ(F²)] = 0.063
wR(F²) = 0.169
S = 1.05
2668 reflections
210 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; 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 global, I. DOI: 10.1107/S1600536811017922/lh5249sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811017922/lh5249Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811017922/lh5249Isup3.cml

checkCIF report

Comment top

The benzimidazole core is of interest because of its diverse biological activies, and it is a well known in medicinal chemistry (Horton et al., 2003). In bioinorganic chemistry, bis-benzimidazoles have been used extensively to help model the active sites of metalloproteins (Holland & Tolman, 2000). The crystal structures of 1,3-bis(1-benzimidazol-2-yl)-2-oxopropane and 1,3-bis(1-benzylbenzimidazol-2-yl)-2-oxopropane have been reported previously (Wu et al. 2009; Chen et al.. 2009). The molecular structure of the title compound is shown in Fig.1. The dihedral angle between the mean planes of the two benzimidazole ring systems is 61.5 (1) Å.

Related literature top

For biological applications of benzimidazoles and bis-benzimidazoles, see: Horton et al. (2003); Holland & Tolman (2000). For related structures, see: Chen et al. (2009); Wu et al. (2009).

Experimental top

A solution of 5.56 g (20 mmol) of 1.3-bis(benzimidazol-2-yl)-2-oxpropane with 1.56 g (40 mmol) potassium in the 150 ml tetrahydrofuran followed by addition 5.68 g (40 mmol) methyl iodide was concentrated and recrystallized from methanol, formimg white blocks suitable for X-ray diffraction studies.(found: C, 70.50; H, 5.83; N, 18.34. Calad.: C, 70.57; H, 5.92; N, 18.29)

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); 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. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity.

1,3-Bis(1-methyl-1H-benzimidazol-2-yl)-2-oxapropane top

Crystal data top

C₁₈H₁₈N₄O	F(000) = 648
M_r = 306.36	D_x = 1.333 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1941 reflections
a = 6.634 (6) Å	θ = 2.5–23.0°
b = 16.217 (15) Å	µ = 0.09 mm⁻¹
c = 14.457 (13) Å	T = 296 K
β = 101.102 (10)°	Block, white
V = 1526 (2) Å³	0.26 × 0.24 × 0.21 mm
Z = 4

Data collection top

Bruker APEXII CCD diffractometer	2668 independent reflections
Radiation source: fine-focus sealed tube	1846 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.057
ω scans	θ_max = 25.0°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→7
T_min = 0.978, T_max = 0.982	k = −17→19
10239 measured reflections	l = −17→17

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.063	H-atom parameters constrained
wR(F²) = 0.169	w = 1/[σ²(F_o²) + (0.062P)² + 1.2125P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
2668 reflections	Δρ_max = 0.19 e Å⁻³
210 parameters	Δρ_min = −0.19 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0025 (4)

Crystal data top

C₁₈H₁₈N₄O	V = 1526 (2) Å³
M_r = 306.36	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 6.634 (6) Å	µ = 0.09 mm⁻¹
b = 16.217 (15) Å	T = 296 K
c = 14.457 (13) Å	0.26 × 0.24 × 0.21 mm
β = 101.102 (10)°

Data collection top

Bruker APEXII CCD diffractometer	2668 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	1846 reflections with I > 2σ(I)
T_min = 0.978, T_max = 0.982	R_int = 0.057
10239 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.063	0 restraints
wR(F²) = 0.169	H-atom parameters constrained
S = 1.05	Δρ_max = 0.19 e Å⁻³
2668 reflections	Δρ_min = −0.19 e Å⁻³
210 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 > σ(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
O1	0.1874 (3)	0.23663 (13)	0.39791 (14)	0.0471 (6)
N3	0.4241 (4)	0.11107 (15)	0.52270 (17)	0.0410 (6)
N1	0.2920 (4)	0.23299 (15)	0.19655 (17)	0.0439 (6)
C11	0.2170 (4)	0.12133 (18)	0.5023 (2)	0.0407 (7)
N2	−0.0371 (4)	0.19270 (17)	0.16948 (18)	0.0489 (7)
C12	0.2789 (5)	0.05940 (18)	0.6348 (2)	0.0427 (7)
C8	0.2615 (5)	0.18872 (19)	0.1131 (2)	0.0437 (8)
N4	0.1227 (4)	0.09232 (16)	0.56732 (18)	0.0467 (7)
C17	0.4691 (5)	0.07179 (18)	0.6089 (2)	0.0410 (7)
C3	0.0574 (5)	0.1645 (2)	0.0974 (2)	0.0463 (8)
C2	0.1090 (5)	0.23293 (19)	0.2256 (2)	0.0424 (7)
C16	0.6514 (5)	0.0441 (2)	0.6624 (2)	0.0524 (9)
H16	0.7768	0.0531	0.6444	0.063*
C18	0.5751 (5)	0.1358 (2)	0.4666 (2)	0.0505 (8)
H18A	0.5239	0.1228	0.4015	0.076*
H18B	0.7014	0.1067	0.4882	0.076*
H18C	0.5990	0.1940	0.4731	0.076*
C13	0.2710 (6)	0.0182 (2)	0.7183 (2)	0.0553 (9)
H13	0.1466	0.0102	0.7377	0.066*
C10	0.1078 (5)	0.1576 (2)	0.4120 (2)	0.0482 (8)
H10A	0.1235	0.1217	0.3602	0.058*
H10B	−0.0376	0.1620	0.4129	0.058*
C15	0.6381 (6)	0.0023 (2)	0.7440 (2)	0.0610 (10)
H15	0.7574	−0.0179	0.7818	0.073*
C1	0.0810 (5)	0.2749 (2)	0.3144 (2)	0.0494 (8)
H1A	0.1279	0.3315	0.3132	0.059*
H1B	−0.0643	0.2763	0.3162	0.059*
C4	−0.0213 (6)	0.1176 (2)	0.0180 (2)	0.0612 (10)
H4A	−0.1579	0.1007	0.0055	0.073*
C7	0.3946 (6)	0.1688 (2)	0.0531 (2)	0.0550 (9)
H7	0.5310	0.1858	0.0645	0.066*
C5	0.1093 (7)	0.0971 (2)	−0.0410 (2)	0.0675 (11)
H5	0.0601	0.0654	−0.0942	0.081*
C9	0.4856 (5)	0.2688 (2)	0.2415 (3)	0.0614 (10)
H9A	0.4693	0.2959	0.2986	0.092*
H9B	0.5290	0.3082	0.1998	0.092*
H9C	0.5871	0.2261	0.2559	0.092*
C6	0.3114 (7)	0.1222 (2)	−0.0240 (2)	0.0657 (11)
H6	0.3943	0.1070	−0.0662	0.079*
C14	0.4501 (6)	−0.0104 (2)	0.7712 (2)	0.0616 (10)
H14	0.4465	−0.0391	0.8266	0.074*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0496 (12)	0.0464 (13)	0.0446 (12)	−0.0009 (10)	0.0075 (10)	0.0015 (10)
N3	0.0392 (14)	0.0429 (14)	0.0424 (14)	−0.0022 (11)	0.0119 (11)	−0.0009 (11)
N1	0.0427 (15)	0.0459 (15)	0.0439 (15)	−0.0012 (12)	0.0102 (11)	0.0036 (12)
C11	0.0399 (17)	0.0407 (17)	0.0426 (17)	−0.0002 (14)	0.0106 (13)	−0.0045 (14)
N2	0.0466 (16)	0.0534 (17)	0.0468 (15)	0.0040 (13)	0.0090 (12)	0.0063 (13)
C12	0.0520 (19)	0.0372 (17)	0.0407 (17)	0.0057 (14)	0.0134 (14)	−0.0051 (13)
C8	0.053 (2)	0.0408 (18)	0.0398 (17)	0.0079 (15)	0.0153 (14)	0.0134 (14)
N4	0.0443 (15)	0.0505 (16)	0.0479 (15)	0.0059 (12)	0.0151 (12)	0.0048 (12)
C17	0.0447 (17)	0.0352 (17)	0.0423 (17)	0.0015 (14)	0.0063 (13)	−0.0076 (13)
C3	0.0506 (19)	0.0472 (19)	0.0399 (17)	0.0044 (15)	0.0057 (14)	0.0075 (14)
C2	0.0401 (17)	0.0438 (18)	0.0433 (17)	0.0076 (14)	0.0075 (14)	0.0079 (14)
C16	0.0474 (19)	0.048 (2)	0.058 (2)	0.0011 (15)	0.0009 (15)	−0.0067 (16)
C18	0.0440 (18)	0.053 (2)	0.059 (2)	−0.0054 (16)	0.0199 (15)	−0.0034 (16)
C13	0.066 (2)	0.054 (2)	0.050 (2)	0.0105 (17)	0.0214 (17)	0.0032 (16)
C10	0.0456 (18)	0.054 (2)	0.0453 (18)	−0.0070 (16)	0.0084 (14)	0.0050 (15)
C15	0.070 (2)	0.048 (2)	0.057 (2)	0.0137 (18)	−0.0074 (18)	−0.0001 (17)
C1	0.055 (2)	0.0468 (19)	0.0469 (18)	0.0086 (16)	0.0113 (15)	0.0040 (15)
C4	0.072 (2)	0.055 (2)	0.052 (2)	−0.0047 (19)	0.0003 (18)	0.0031 (17)
C7	0.065 (2)	0.052 (2)	0.052 (2)	0.0065 (17)	0.0228 (17)	0.0138 (17)
C5	0.102 (3)	0.059 (2)	0.042 (2)	0.002 (2)	0.014 (2)	−0.0020 (17)
C9	0.051 (2)	0.070 (2)	0.065 (2)	−0.0092 (18)	0.0124 (17)	0.0022 (19)
C6	0.095 (3)	0.060 (2)	0.050 (2)	0.014 (2)	0.032 (2)	0.0097 (18)
C14	0.089 (3)	0.049 (2)	0.0462 (19)	0.014 (2)	0.0103 (19)	0.0023 (16)

Geometric parameters (Å, º) top

O1—C10	1.416 (4)	C18—H18A	0.9600
O1—C1	1.419 (4)	C18—H18B	0.9600
N3—C11	1.359 (4)	C18—H18C	0.9600
N3—C17	1.380 (4)	C13—C14	1.364 (5)
N3—C18	1.461 (4)	C13—H13	0.9300
N1—C2	1.359 (4)	C10—H10A	0.9700
N1—C8	1.385 (4)	C10—H10B	0.9700
N1—C9	1.445 (4)	C15—C14	1.394 (5)
C11—N4	1.313 (4)	C15—H15	0.9300
C11—C10	1.486 (4)	C1—H1A	0.9700
N2—C2	1.311 (4)	C1—H1B	0.9700
N2—C3	1.392 (4)	C4—C5	1.369 (5)
C12—N4	1.386 (4)	C4—H4A	0.9300
C12—C13	1.390 (4)	C7—C6	1.372 (5)
C12—C17	1.398 (4)	C7—H7	0.9300
C8—C3	1.386 (4)	C5—C6	1.377 (5)
C8—C7	1.389 (4)	C5—H5	0.9300
C17—C16	1.380 (4)	C9—H9A	0.9600
C3—C4	1.393 (5)	C9—H9B	0.9600
C2—C1	1.497 (4)	C9—H9C	0.9600
C16—C15	1.378 (5)	C6—H6	0.9300
C16—H16	0.9300	C14—H14	0.9300

C10—O1—C1	112.4 (2)	C12—C13—H13	120.8
C11—N3—C17	106.7 (2)	O1—C10—C11	110.6 (2)
C11—N3—C18	128.2 (3)	O1—C10—H10A	109.5
C17—N3—C18	125.1 (3)	C11—C10—H10A	109.5
C2—N1—C8	106.2 (2)	O1—C10—H10B	109.5
C2—N1—C9	129.1 (3)	C11—C10—H10B	109.5
C8—N1—C9	124.6 (3)	H10A—C10—H10B	108.1
N4—C11—N3	113.7 (3)	C16—C15—C14	121.5 (3)
N4—C11—C10	123.5 (3)	C16—C15—H15	119.2
N3—C11—C10	122.7 (3)	C14—C15—H15	119.2
C2—N2—C3	103.9 (3)	O1—C1—C2	114.0 (3)
N4—C12—C13	130.4 (3)	O1—C1—H1A	108.7
N4—C12—C17	110.3 (3)	C2—C1—H1A	108.7
C13—C12—C17	119.3 (3)	O1—C1—H1B	108.7
N1—C8—C3	105.2 (3)	C2—C1—H1B	108.7
N1—C8—C7	131.3 (3)	H1A—C1—H1B	107.6
C3—C8—C7	123.4 (3)	C5—C4—C3	117.7 (4)
C11—N4—C12	104.3 (3)	C5—C4—H4A	121.2
N3—C17—C16	132.2 (3)	C3—C4—H4A	121.2
N3—C17—C12	105.0 (3)	C6—C7—C8	115.5 (3)
C16—C17—C12	122.8 (3)	C6—C7—H7	122.3
C8—C3—N2	110.6 (3)	C8—C7—H7	122.3
C8—C3—C4	119.2 (3)	C4—C5—C6	121.9 (4)
N2—C3—C4	130.2 (3)	C4—C5—H5	119.0
N2—C2—N1	114.1 (3)	C6—C5—H5	119.0
N2—C2—C1	123.9 (3)	N1—C9—H9A	109.5
N1—C2—C1	122.0 (3)	N1—C9—H9B	109.5
C15—C16—C17	116.6 (3)	H9A—C9—H9B	109.5
C15—C16—H16	121.7	N1—C9—H9C	109.5
C17—C16—H16	121.7	H9A—C9—H9C	109.5
N3—C18—H18A	109.5	H9B—C9—H9C	109.5
N3—C18—H18B	109.5	C7—C6—C5	122.3 (3)
H18A—C18—H18B	109.5	C7—C6—H6	118.9
N3—C18—H18C	109.5	C5—C6—H6	118.9
H18A—C18—H18C	109.5	C13—C14—C15	121.4 (3)
H18B—C18—H18C	109.5	C13—C14—H14	119.3
C14—C13—C12	118.4 (3)	C15—C14—H14	119.3
C14—C13—H13	120.8

Experimental details

Crystal data
Chemical formula	C₁₈H₁₈N₄O
M_r	306.36
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	296
a, b, c (Å)	6.634 (6), 16.217 (15), 14.457 (13)
β (°)	101.102 (10)
V (Å³)	1526 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.26 × 0.24 × 0.21

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.978, 0.982
No. of measured, independent and observed [I > 2σ(I)] reflections	10239, 2668, 1846
R_int	0.057
(sin θ/λ)_max (Å⁻¹)	0.594

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.063, 0.169, 1.05
No. of reflections	2668
No. of parameters	210
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.19, −0.19

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

The authors acknowledge financial support and a grant from the `Qing Lan' Talent Engineering Funds and the Students' Science and Technology Innovation Funds (grant No. DXS2011–002) of Lanzhou Jiaotong University. A grant from the Middle-Young Age Science Foundation (grant No. 3YS061-A25–023) and the `Long Yuan Qing Nian' of Gansu Province is also acknowledged.

References

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