Ethyl 1-(butan-2-yl)-2-(2-meth-oxy-phen-yl)-1H-benzimidazole-5-carboxyl-ate.

In the title compound, C(21)H(24)N(2)O(3), the mean planes of the benzene ring and the benzimidazole ring system form a dihedral angle of 69.94 (7)°. The ethyl group atoms of the ethano-ate fragment are disordered over two sets of sites, with refined occupancies of 0.742 (6) and 0.258 (6). In the crystal, there are weak C-H⋯N hydrogen bonds which connect mol-ecules into chains along the b axis. A weak inter-molecular C-H⋯π inter-action is also observed.

Related literature

For the synthesis and a closely related structure, see: Arumugam et al. (2010 ▶). For background to microwave chemistry, see: Kappe & Dallinger (2006 ▶); Hamzah et al. (2011 ▶). For the synthesis of benzimidazole derivatives and their applications, see: Wang et al. (2011 ▶); VanVliet et al. (2005 ▶); Loupy (2002 ▶); Santagada et al. (2001 ▶); Nicolaou et al. (2000 ▶); Evans et al. (1988 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C21H24N2O3

M = 352.42

Monoclinic,

a = 10.6746 (3) Å

b = 12.3344 (4) Å

c = 15.6158 (5) Å

β = 106.901 (1)°

V = 1967.25 (11) Å3

Z = 4

Mo Kα radiation

μ = 0.08 mm−1

T = 296 K

0.52 × 0.44 × 0.32 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T min = 0.959, T max = 0.975

17688 measured reflections

3475 independent reflections

2712 reflections with I > 2σ(I)

R int = 0.025

Refinement

R[F 2 > 2σ(F 2)] = 0.045

wR(F 2) = 0.122

S = 1.05

3475 reflections

245 parameters

3 restraints

H-atom parameters constrained

Δρmax = 0.35 e Å−3

Δρmin = −0.18 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 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811046095/lh5357sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811046095/lh5357Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811046095/lh5357Isup3.cml

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

C21H24N2O3	F(000) = 752
Mr = 352.42	Dx = 1.190 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 8039 reflections
a = 10.6746 (3) Å	θ = 2.1–25.0°
b = 12.3344 (4) Å	µ = 0.08 mm−1
c = 15.6158 (5) Å	T = 296 K
β = 106.901 (1)°	Block, colourless
V = 1967.25 (11) Å3	0.52 × 0.44 × 0.32 mm
Z = 4

Bruker SMART APEXII CCD area-detector diffractometer	3475 independent reflections
Radiation source: fine-focus sealed tube	2712 reflections with I > 2σ(I)
graphite	Rint = 0.025
Detector resolution: 83.66 pixels mm-1	θmax = 25.0°, θmin = 2.1°
φ and ω scan	h = −11→12
Absorption correction: multi-scan (SADABS; Bruker, 2009)	k = −11→14
Tmin = 0.959, Tmax = 0.975	l = −18→17
17688 measured reflections

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.122	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0526P)2 + 0.5324P] where P = (Fo2 + 2Fc2)/3
3475 reflections	(Δ/σ)max < 0.001
245 parameters	Δρmax = 0.35 e Å−3
3 restraints	Δρmin = −0.18 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
O1	0.22019 (14)	0.60261 (11)	0.83252 (9)	0.0694 (4)
O2	0.16647 (18)	1.12078 (12)	1.21044 (10)	0.0894 (5)
O3	0.10964 (19)	1.17279 (12)	1.06857 (10)	0.0917 (5)
N1	0.29480 (16)	0.88252 (11)	0.90695 (9)	0.0562 (4)
N2	0.36352 (14)	0.74369 (11)	1.00207 (8)	0.0475 (3)
C1	0.34617 (16)	0.78558 (13)	0.91776 (10)	0.0467 (4)
C2	0.32104 (16)	0.82294 (12)	1.04995 (10)	0.0445 (4)
C3	0.31600 (18)	0.82949 (14)	1.13790 (11)	0.0551 (5)
H3	0.3450	0.7729	1.1781	0.066*
C4	0.26638 (18)	0.92316 (14)	1.16254 (11)	0.0542 (4)
H4	0.2638	0.9304	1.2213	0.065*
C5	0.21963 (17)	1.00806 (13)	1.10246 (11)	0.0496 (4)
C6	0.22494 (19)	1.00099 (13)	1.01515 (11)	0.0540 (5)
H6	0.1942	1.0572	0.9748	0.065*
C7	0.27727 (17)	0.90788 (13)	0.98941 (10)	0.0473 (4)
C8	0.38804 (17)	0.72852 (14)	0.84697 (10)	0.0498 (4)
C9	0.49117 (19)	0.76994 (16)	0.82051 (12)	0.0606 (5)
H9	0.5345	0.8316	0.8484	0.073*
C10	0.5308 (2)	0.72096 (19)	0.75319 (13)	0.0711 (6)
H10	0.6003	0.7493	0.7358	0.085*
C11	0.4666 (2)	0.63017 (18)	0.71234 (13)	0.0694 (6)
H11	0.4939	0.5966	0.6675	0.083*
C12	0.3627 (2)	0.58773 (16)	0.73630 (11)	0.0608 (5)
H12	0.3196	0.5264	0.7076	0.073*
C13	0.32254 (18)	0.63726 (14)	0.80372 (11)	0.0517 (4)
C14	0.1359 (2)	0.52171 (19)	0.78162 (15)	0.0819 (6)
H14A	0.0981	0.5473	0.7216	0.123*
H14B	0.0675	0.5063	0.8084	0.123*
H14C	0.1852	0.4569	0.7805	0.123*
C15	0.42814 (19)	0.63962 (14)	1.03579 (12)	0.0601 (5)
H15	0.4483	0.6042	0.9852	0.072*
C16	0.3357 (2)	0.56259 (16)	1.06687 (15)	0.0782 (6)
H16A	0.3108	0.5957	1.1151	0.117*
H16B	0.3800	0.4955	1.0869	0.117*
H16C	0.2589	0.5488	1.0179	0.117*
C17	0.5563 (2)	0.65788 (19)	1.10606 (15)	0.0816 (6)
H17A	0.5395	0.6900	1.1583	0.098*
H17B	0.5984	0.5884	1.1238	0.098*
C18	0.6475 (2)	0.7294 (2)	1.07565 (18)	0.1013 (8)
H18A	0.6583	0.7017	1.0208	0.152*
H18B	0.7308	0.7312	1.1206	0.152*
H18C	0.6120	0.8014	1.0660	0.152*
C19	0.1636 (2)	1.10442 (15)	1.13428 (13)	0.0599 (5)
C20	0.0550 (11)	1.2722 (4)	1.0931 (10)	0.103 (2)	0.742 (6)
H20A	−0.0207	1.2560	1.1134	0.124*	0.742 (6)
H20B	0.1196	1.3091	1.1409	0.124*	0.742 (6)
C21	0.0176 (5)	1.3391 (3)	1.0141 (4)	0.1145 (15)	0.742 (6)
H21A	−0.0225	1.4045	1.0269	0.172*	0.742 (6)
H21B	−0.0436	1.3005	0.9667	0.172*	0.742 (6)
H21C	0.0938	1.3571	0.9963	0.172*	0.742 (6)
C21A	0.0967 (16)	1.3540 (11)	1.0711 (11)	0.1145 (15)	0.258 (6)
H21D	0.0569	1.4175	1.0873	0.172*	0.258 (6)
H21E	0.0936	1.3581	1.0091	0.172*	0.258 (6)
H21F	0.1863	1.3495	1.1073	0.172*	0.258 (6)
C20A	0.027 (4)	1.2591 (10)	1.086 (3)	0.103 (2)	0.258 (6)
H20C	−0.0605	1.2561	1.0439	0.124*	0.258 (6)
H20D	0.0210	1.2562	1.1463	0.124*	0.258 (6)

	U11	U22	U33	U12	U13	U23
O1	0.0819 (9)	0.0691 (9)	0.0610 (8)	−0.0156 (7)	0.0268 (7)	−0.0184 (6)
O2	0.1453 (15)	0.0707 (10)	0.0661 (9)	0.0110 (9)	0.0526 (10)	−0.0165 (7)
O3	0.1471 (15)	0.0615 (9)	0.0743 (10)	0.0397 (9)	0.0445 (10)	−0.0029 (8)
N1	0.0877 (11)	0.0440 (8)	0.0398 (8)	0.0137 (7)	0.0233 (7)	0.0026 (6)
N2	0.0624 (9)	0.0405 (7)	0.0401 (7)	0.0093 (6)	0.0158 (6)	0.0030 (6)
C1	0.0582 (10)	0.0426 (9)	0.0392 (9)	0.0031 (8)	0.0140 (7)	−0.0008 (7)
C2	0.0558 (10)	0.0399 (9)	0.0390 (9)	0.0005 (7)	0.0158 (7)	0.0000 (7)
C3	0.0745 (12)	0.0514 (10)	0.0420 (9)	0.0053 (9)	0.0212 (8)	0.0077 (8)
C4	0.0724 (12)	0.0558 (11)	0.0394 (9)	−0.0028 (9)	0.0243 (8)	−0.0021 (8)
C5	0.0639 (11)	0.0422 (9)	0.0473 (10)	−0.0050 (8)	0.0233 (8)	−0.0073 (7)
C6	0.0795 (12)	0.0391 (9)	0.0451 (10)	0.0076 (8)	0.0207 (9)	0.0020 (7)
C7	0.0662 (11)	0.0398 (9)	0.0377 (9)	0.0034 (8)	0.0179 (8)	−0.0004 (7)
C8	0.0630 (11)	0.0465 (10)	0.0396 (9)	0.0106 (8)	0.0146 (8)	−0.0004 (7)
C9	0.0673 (12)	0.0607 (12)	0.0557 (11)	0.0019 (9)	0.0206 (9)	−0.0064 (9)
C10	0.0667 (12)	0.0876 (15)	0.0654 (12)	0.0048 (11)	0.0291 (10)	−0.0104 (11)
C11	0.0724 (13)	0.0841 (15)	0.0542 (11)	0.0195 (11)	0.0224 (10)	−0.0142 (10)
C12	0.0739 (13)	0.0579 (11)	0.0455 (10)	0.0130 (10)	0.0093 (9)	−0.0108 (8)
C13	0.0608 (11)	0.0507 (10)	0.0417 (9)	0.0078 (8)	0.0118 (8)	−0.0020 (8)
C14	0.0747 (14)	0.0818 (15)	0.0828 (15)	−0.0122 (12)	0.0129 (11)	−0.0203 (12)
C15	0.0793 (13)	0.0460 (10)	0.0529 (11)	0.0168 (9)	0.0158 (9)	0.0044 (8)
C16	0.1111 (18)	0.0497 (11)	0.0806 (14)	0.0041 (11)	0.0386 (13)	0.0131 (10)
C17	0.0878 (15)	0.0715 (14)	0.0733 (14)	0.0173 (11)	0.0039 (11)	0.0000 (11)
C18	0.0757 (16)	0.101 (2)	0.111 (2)	−0.0132 (13)	0.0018 (13)	−0.0121 (15)
C19	0.0810 (13)	0.0475 (10)	0.0584 (12)	−0.0050 (9)	0.0315 (10)	−0.0091 (9)
C20	0.153 (6)	0.058 (2)	0.108 (4)	0.034 (3)	0.053 (5)	−0.011 (2)
C21	0.117 (4)	0.081 (2)	0.142 (4)	0.041 (3)	0.031 (3)	0.006 (3)
C21A	0.117 (4)	0.081 (2)	0.142 (4)	0.041 (3)	0.031 (3)	0.006 (3)
C20A	0.153 (6)	0.058 (2)	0.108 (4)	0.034 (3)	0.053 (5)	−0.011 (2)

O1—C13	1.365 (2)	C12—C13	1.388 (2)
O1—C14	1.422 (2)	C12—H12	0.9300
O2—C19	1.198 (2)	C14—H14A	0.9600
O3—C19	1.324 (2)	C14—H14B	0.9600
O3—C20A	1.456 (5)	C14—H14C	0.9600
O3—C20	1.456 (4)	C15—C17	1.501 (3)
N1—C1	1.306 (2)	C15—C16	1.546 (3)
N1—C7	1.390 (2)	C15—H15	0.9800
N2—C1	1.376 (2)	C16—H16A	0.9600
N2—C2	1.385 (2)	C16—H16B	0.9600
N2—C15	1.480 (2)	C16—H16C	0.9600
C1—C8	1.485 (2)	C17—C18	1.489 (3)
C2—C3	1.392 (2)	C17—H17A	0.9700
C2—C7	1.397 (2)	C17—H17B	0.9700
C3—C4	1.372 (2)	C18—H18A	0.9600
C3—H3	0.9300	C18—H18B	0.9600
C4—C5	1.398 (2)	C18—H18C	0.9600
C4—H4	0.9300	C20—C21	1.441 (12)
C5—C6	1.384 (2)	C20—H20A	0.9700
C5—C19	1.480 (2)	C20—H20B	0.9700
C6—C7	1.387 (2)	C21—H21A	0.9600
C6—H6	0.9300	C21—H21B	0.9600
C8—C9	1.381 (3)	C21—H21C	0.9600
C8—C13	1.392 (2)	C21A—C20A	1.440 (13)
C9—C10	1.381 (3)	C21A—H21D	0.9600
C9—H9	0.9300	C21A—H21E	0.9600
C10—C11	1.370 (3)	C21A—H21F	0.9600
C10—H10	0.9300	C20A—H20C	0.9700
C11—C12	1.373 (3)	C20A—H20D	0.9700
C11—H11	0.9300
C13—O1—C14	118.20 (15)	N2—C15—C17	111.19 (16)
C19—O3—C20A	118.4 (17)	N2—C15—C16	111.76 (15)
C19—O3—C20	116.7 (6)	C17—C15—C16	113.08 (17)
C1—N1—C7	104.53 (13)	N2—C15—H15	106.8
C1—N2—C2	106.11 (12)	C17—C15—H15	106.8
C1—N2—C15	125.83 (13)	C16—C15—H15	106.8
C2—N2—C15	127.75 (13)	C15—C16—H16A	109.5
N1—C1—N2	113.72 (13)	C15—C16—H16B	109.5
N1—C1—C8	122.94 (14)	H16A—C16—H16B	109.5
N2—C1—C8	123.27 (14)	C15—C16—H16C	109.5
N2—C2—C3	133.33 (15)	H16A—C16—H16C	109.5
N2—C2—C7	105.16 (13)	H16B—C16—H16C	109.5
C3—C2—C7	121.52 (15)	C18—C17—C15	113.38 (19)
C4—C3—C2	117.02 (15)	C18—C17—H17A	108.9
C4—C3—H3	121.5	C15—C17—H17A	108.9
C2—C3—H3	121.5	C18—C17—H17B	108.9
C3—C4—C5	122.30 (15)	C15—C17—H17B	108.9
C3—C4—H4	118.8	H17A—C17—H17B	107.7
C5—C4—H4	118.8	C17—C18—H18A	109.5
C6—C5—C4	120.35 (15)	C17—C18—H18B	109.5
C6—C5—C19	121.18 (16)	H18A—C18—H18B	109.5
C4—C5—C19	118.47 (15)	C17—C18—H18C	109.5
C5—C6—C7	118.24 (15)	H18A—C18—H18C	109.5
C5—C6—H6	120.9	H18B—C18—H18C	109.5
C7—C6—H6	120.9	O2—C19—O3	122.81 (18)
C6—C7—N1	128.98 (15)	O2—C19—C5	124.93 (19)
C6—C7—C2	120.55 (14)	O3—C19—C5	112.26 (15)
N1—C7—C2	110.46 (14)	C21—C20—O3	106.8 (8)
C9—C8—C13	119.04 (15)	C21—C20—H20A	110.4
C9—C8—C1	119.08 (16)	O3—C20—H20A	110.4
C13—C8—C1	121.81 (16)	C21—C20—H20B	110.4
C10—C9—C8	120.85 (19)	O3—C20—H20B	110.4
C10—C9—H9	119.6	H20A—C20—H20B	108.6
C8—C9—H9	119.6	C20—C21—H21A	109.5
C11—C10—C9	119.33 (19)	C20—C21—H21B	109.5
C11—C10—H10	120.3	H21A—C21—H21B	109.5
C9—C10—H10	120.3	C20—C21—H21C	109.5
C10—C11—C12	121.27 (17)	H21A—C21—H21C	109.5
C10—C11—H11	119.4	H21B—C21—H21C	109.5
C12—C11—H11	119.4	C20A—C21A—H21D	109.5
C11—C12—C13	119.38 (18)	C20A—C21A—H21E	109.5
C11—C12—H12	120.3	H21D—C21A—H21E	109.5
C13—C12—H12	120.3	C20A—C21A—H21F	109.5
O1—C13—C12	124.40 (17)	H21D—C21A—H21F	109.5
O1—C13—C8	115.49 (14)	H21E—C21A—H21F	109.5
C12—C13—C8	120.11 (17)	C21A—C20A—O3	101.4 (11)
O1—C14—H14A	109.5	C21A—C20A—H20C	111.5
O1—C14—H14B	109.5	O3—C20A—H20C	111.5
H14A—C14—H14B	109.5	C21A—C20A—H20D	111.5
O1—C14—H14C	109.5	O3—C20A—H20D	111.5
H14A—C14—H14C	109.5	H20C—C20A—H20D	109.3
H14B—C14—H14C	109.5
C7—N1—C1—N2	0.4 (2)	C1—C8—C9—C10	−178.21 (17)
C7—N1—C1—C8	−176.62 (16)	C8—C9—C10—C11	0.0 (3)
C2—N2—C1—N1	−1.2 (2)	C9—C10—C11—C12	0.8 (3)
C15—N2—C1—N1	−175.22 (16)	C10—C11—C12—C13	−0.5 (3)
C2—N2—C1—C8	175.86 (16)	C14—O1—C13—C12	−10.5 (3)
C15—N2—C1—C8	1.8 (3)	C14—O1—C13—C8	169.60 (17)
C1—N2—C2—C3	−178.75 (18)	C11—C12—C13—O1	179.54 (17)
C15—N2—C2—C3	−4.9 (3)	C11—C12—C13—C8	−0.6 (3)
C1—N2—C2—C7	1.37 (18)	C9—C8—C13—O1	−178.76 (16)
C15—N2—C2—C7	175.26 (16)	C1—C8—C13—O1	−1.7 (2)
N2—C2—C3—C4	180.00 (18)	C9—C8—C13—C12	1.3 (3)
C7—C2—C3—C4	−0.1 (3)	C1—C8—C13—C12	178.40 (16)
C2—C3—C4—C5	1.5 (3)	C1—N2—C15—C17	111.1 (2)
C3—C4—C5—C6	−1.5 (3)	C2—N2—C15—C17	−61.7 (2)
C3—C4—C5—C19	177.90 (17)	C1—N2—C15—C16	−121.50 (19)
C4—C5—C6—C7	0.2 (3)	C2—N2—C15—C16	65.7 (2)
C19—C5—C6—C7	−179.26 (17)	N2—C15—C17—C18	−55.0 (2)
C5—C6—C7—N1	−178.97 (17)	C16—C15—C17—C18	178.28 (19)
C5—C6—C7—C2	1.2 (3)	C20A—O3—C19—O2	−13.3 (18)
C1—N1—C7—C6	−179.38 (19)	C20—O3—C19—O2	1.3 (5)
C1—N1—C7—C2	0.5 (2)	C20A—O3—C19—C5	167.2 (17)
N2—C2—C7—C6	178.70 (16)	C20—O3—C19—C5	−178.2 (5)
C3—C2—C7—C6	−1.2 (3)	C6—C5—C19—O2	−172.8 (2)
N2—C2—C7—N1	−1.19 (19)	C4—C5—C19—O2	7.8 (3)
C3—C2—C7—N1	178.91 (16)	C6—C5—C19—O3	6.7 (3)
N1—C1—C8—C9	65.8 (2)	C4—C5—C19—O3	−172.74 (17)
N2—C1—C8—C9	−110.9 (2)	C19—O3—C20—C21	172.8 (5)
N1—C1—C8—C13	−111.2 (2)	C20A—O3—C20—C21	−86 (10)
N2—C1—C8—C13	72.0 (2)	C19—O3—C20A—C21A	119 (2)
C13—C8—C9—C10	−1.1 (3)	C20—O3—C20A—C21A	33 (6)

Cg is the centroid of the N1/N2/C1/C2/C7 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12···N1i	0.93	2.56	3.471 (2)	165
C20A—H20C···Cgii	0.97	2.90	3.71 (4)	141

Table 1

Hydrogen-bond geometry (Å, °)

Cg is the centroid of the N1/N2/C1/C2/C7 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12⋯N1i	0.93	2.56	3.471 (2)	165
C20A—H20C⋯Cgii	0.97	2.90	3.71 (4)	141

Symmetry codes: (i) ; (ii) .