Ethyl 1-sec-butyl-2-p-tolyl-1H-benzimidazole-5-carboxyl-ate.

In the title compound, C(21)H(24)N(2)O(2), the butyl group is disordered over two orientations with refined site occupancies of 0.883 (3) and 0.117 (3). The dihedral angle between the mean plane of benzimidazole ring system and the benzene ring is 39.32 (4)° and the dihedral angle between the mean plane of carboxyl-ate group and the benzimidazole ring system is 6.87 (5)°. A weak intra-molecular C-H⋯π inter-action may have some influence on the conformation of the mol-ecule. In the crystal structure, mol-ecules are linked into infinite chains along the b axis by weak inter-molecular C-H⋯O hydrogen bonds.

Related literature

For background information on benzimidazole derivatives, their biological activity and medical applications, see: Richter (1997 ▶); Can-Eke et al. (1998 ▶); Evans et al. (1997 ▶); Garuti et al. (2000 ▶); Sondhi et al. (2005 ▶). For the synthesis of the title compound and related structures, see: Arumugam et al. (2010a ▶,b ▶,c ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C21H24N2O2

M = 336.42

Monoclinic,

a = 10.6093 (7) Å

b = 12.5617 (9) Å

c = 13.6025 (10) Å

β = 96.412 (2)°

V = 1801.5 (2) Å3

Z = 4

Mo Kα radiation

μ = 0.08 mm−1

T = 100 K

0.46 × 0.29 × 0.24 mm

Data collection

Bruker APEXII DUO CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T min = 0.964, T max = 0.981

31247 measured reflections

8425 independent reflections

6598 reflections with I > 2σ(I)

R int = 0.050

Refinement

R[F 2 > 2σ(F 2)] = 0.051

wR(F 2) = 0.177

S = 1.08

8425 reflections

249 parameters

H-atom parameters constrained

Δρmax = 0.58 e Å−3

Δρmin = −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 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810015242/lh5024sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810015242/lh5024Isup2.hkl

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

C21H24N2O2	F(000) = 720
Mr = 336.42	Dx = 1.240 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9348 reflections
a = 10.6093 (7) Å	θ = 2.5–35.7°
b = 12.5617 (9) Å	µ = 0.08 mm−1
c = 13.6025 (10) Å	T = 100 K
β = 96.412 (2)°	Block, colourless
V = 1801.5 (2) Å3	0.46 × 0.29 × 0.24 mm
Z = 4

Bruker APEXII DUO CCD area-detector diffractometer	8425 independent reflections
Radiation source: fine-focus sealed tube	6598 reflections with I > 2σ(I)
graphite	Rint = 0.050
φ and ω scans	θmax = 35.9°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −17→17
Tmin = 0.964, Tmax = 0.981	k = −20→18
31247 measured reflections	l = −22→22

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.177	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.0965P)2 + 0.2974P] where P = (Fo2 + 2Fc2)/3
8425 reflections	(Δ/σ)max = 0.001
249 parameters	Δρmax = 0.58 e Å−3
0 restraints	Δρmin = −0.35 e Å−3

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	0.49342 (7)	0.02746 (7)	0.17217 (6)	0.02380 (16)
O2	0.65726 (7)	−0.02944 (6)	0.09409 (6)	0.02268 (16)
N1	0.97240 (7)	0.27803 (6)	0.12066 (6)	0.01543 (14)
N2	0.88175 (7)	0.41780 (6)	0.19145 (6)	0.01655 (14)
C1	1.08554 (9)	0.54848 (8)	0.10257 (7)	0.01777 (16)
H1A	1.0063	0.5810	0.0955	0.021*
C2	1.19164 (9)	0.60526 (8)	0.08166 (7)	0.01913 (17)
H2A	1.1826	0.6757	0.0611	0.023*
C3	1.31155 (9)	0.55829 (8)	0.09096 (7)	0.01821 (16)
C4	1.32288 (9)	0.45317 (8)	0.12279 (8)	0.02007 (17)
H4A	1.4023	0.4209	0.1299	0.024*
C5	1.21734 (8)	0.39545 (8)	0.14411 (7)	0.01823 (16)
H5A	1.2267	0.3251	0.1651	0.022*
C6	1.09738 (8)	0.44266 (7)	0.13421 (7)	0.01533 (15)
C7	0.98590 (8)	0.37775 (7)	0.15004 (7)	0.01501 (15)
C8	0.85266 (8)	0.24973 (7)	0.14314 (6)	0.01444 (14)
C9	0.78890 (8)	0.15330 (7)	0.12648 (7)	0.01558 (15)
H9A	0.8262	0.0964	0.0969	0.019*
C10	0.66749 (8)	0.14490 (7)	0.15547 (7)	0.01544 (15)
C11	0.61067 (8)	0.23144 (8)	0.19943 (7)	0.01795 (16)
H11A	0.5293	0.2235	0.2176	0.022*
C12	0.67222 (9)	0.32803 (8)	0.21644 (7)	0.01830 (16)
H12A	0.6344	0.3848	0.2457	0.022*
C13	0.79460 (8)	0.33574 (7)	0.18720 (7)	0.01546 (15)
C14	0.59579 (9)	0.04345 (8)	0.14279 (7)	0.01746 (16)
C15	0.59689 (11)	−0.13214 (8)	0.07980 (9)	0.0248 (2)
H15A	0.5092	−0.1239	0.0519	0.030*
H15B	0.5987	−0.1694	0.1424	0.030*
C16	0.67033 (12)	−0.19304 (10)	0.00983 (10)	0.0309 (2)
H16A	0.6344	−0.2628	−0.0007	0.046*
H16B	0.7572	−0.1992	0.0377	0.046*
H16C	0.6662	−0.1560	−0.0522	0.046*
C17	0.88130 (11)	0.51250 (9)	0.25531 (10)	0.0177 (2)	0.883 (3)
H17A	0.9632	0.5481	0.2535	0.021*	0.883 (3)
C18	0.77857 (12)	0.59232 (10)	0.21723 (12)	0.0295 (3)	0.883 (3)
H18A	0.7830	0.6054	0.1482	0.044*	0.883 (3)
H18B	0.7915	0.6578	0.2533	0.044*	0.883 (3)
H18C	0.6967	0.5639	0.2263	0.044*	0.883 (3)
C19	0.87392 (12)	0.47809 (11)	0.36205 (9)	0.0252 (3)	0.883 (3)
H19A	0.8852	0.5399	0.4048	0.030*	0.883 (3)
H19B	0.7904	0.4489	0.3678	0.030*	0.883 (3)
C20	0.97390 (13)	0.39537 (13)	0.39635 (9)	0.0283 (3)	0.883 (3)
H20A	0.9696	0.3794	0.4649	0.042*	0.883 (3)
H20B	1.0565	0.4228	0.3880	0.042*	0.883 (3)
H20C	0.9588	0.3317	0.3578	0.042*	0.883 (3)
C17B	0.9123 (10)	0.4910 (8)	0.2883 (8)	0.0205 (17)*	0.117 (3)
H17B	0.9914	0.5291	0.2810	0.025*	0.117 (3)
C18B	0.9279 (12)	0.4407 (10)	0.3838 (8)	0.028 (2)*	0.117 (3)
H18D	0.9359	0.4942	0.4345	0.042*	0.117 (3)
H18E	1.0028	0.3973	0.3895	0.042*	0.117 (3)
H18F	0.8553	0.3970	0.3912	0.042*	0.117 (3)
C19B	0.8068 (10)	0.5725 (9)	0.2776 (8)	0.028 (2)*	0.117 (3)
H19C	0.8237	0.6249	0.3298	0.034*	0.117 (3)
H19D	0.7281	0.5370	0.2878	0.034*	0.117 (3)
C20B	0.7858 (14)	0.6360 (12)	0.1703 (11)	0.041 (3)*	0.117 (3)
H20D	0.7288	0.6946	0.1751	0.061*	0.117 (3)
H20E	0.7507	0.5879	0.1196	0.061*	0.117 (3)
H20F	0.8659	0.6623	0.1541	0.061*	0.117 (3)
C21	1.42509 (11)	0.62003 (10)	0.06554 (8)	0.0258 (2)
H21A	1.5001	0.5936	0.1038	0.039*
H21B	1.4142	0.6940	0.0802	0.039*
H21C	1.4334	0.6119	−0.0036	0.039*

	U11	U22	U33	U12	U13	U23
O1	0.0180 (3)	0.0222 (4)	0.0325 (4)	−0.0070 (2)	0.0084 (3)	−0.0006 (3)
O2	0.0226 (3)	0.0155 (3)	0.0316 (4)	−0.0089 (2)	0.0100 (3)	−0.0062 (3)
N1	0.0142 (3)	0.0130 (3)	0.0200 (3)	−0.0026 (2)	0.0059 (2)	−0.0017 (2)
N2	0.0157 (3)	0.0132 (3)	0.0217 (3)	−0.0031 (2)	0.0066 (3)	−0.0045 (2)
C1	0.0181 (4)	0.0147 (4)	0.0207 (4)	−0.0026 (3)	0.0031 (3)	0.0002 (3)
C2	0.0231 (4)	0.0151 (4)	0.0195 (4)	−0.0057 (3)	0.0035 (3)	0.0004 (3)
C3	0.0187 (4)	0.0190 (4)	0.0175 (4)	−0.0073 (3)	0.0046 (3)	−0.0017 (3)
C4	0.0163 (4)	0.0195 (4)	0.0252 (4)	−0.0035 (3)	0.0057 (3)	0.0000 (3)
C5	0.0160 (3)	0.0152 (4)	0.0242 (4)	−0.0019 (3)	0.0056 (3)	0.0004 (3)
C6	0.0153 (3)	0.0138 (4)	0.0174 (3)	−0.0034 (3)	0.0044 (3)	−0.0016 (3)
C7	0.0141 (3)	0.0135 (4)	0.0181 (3)	−0.0025 (2)	0.0047 (3)	−0.0014 (3)
C8	0.0139 (3)	0.0123 (3)	0.0178 (3)	−0.0025 (2)	0.0045 (3)	−0.0015 (3)
C9	0.0155 (3)	0.0127 (3)	0.0192 (4)	−0.0028 (3)	0.0048 (3)	−0.0018 (3)
C10	0.0153 (3)	0.0139 (4)	0.0175 (3)	−0.0037 (3)	0.0037 (3)	−0.0001 (3)
C11	0.0145 (3)	0.0184 (4)	0.0217 (4)	−0.0024 (3)	0.0056 (3)	−0.0012 (3)
C12	0.0153 (3)	0.0168 (4)	0.0238 (4)	−0.0016 (3)	0.0068 (3)	−0.0038 (3)
C13	0.0142 (3)	0.0135 (4)	0.0193 (4)	−0.0026 (3)	0.0047 (3)	−0.0028 (3)
C14	0.0166 (3)	0.0162 (4)	0.0197 (4)	−0.0044 (3)	0.0027 (3)	0.0008 (3)
C15	0.0265 (5)	0.0175 (4)	0.0314 (5)	−0.0108 (3)	0.0076 (4)	−0.0043 (4)
C16	0.0303 (5)	0.0212 (5)	0.0426 (6)	−0.0081 (4)	0.0110 (5)	−0.0081 (4)
C17	0.0177 (4)	0.0137 (4)	0.0224 (5)	−0.0019 (3)	0.0046 (4)	−0.0060 (4)
C18	0.0230 (5)	0.0171 (5)	0.0492 (9)	0.0041 (4)	0.0076 (5)	−0.0052 (5)
C19	0.0232 (5)	0.0321 (7)	0.0213 (5)	−0.0070 (5)	0.0070 (4)	−0.0101 (4)
C20	0.0289 (6)	0.0361 (7)	0.0195 (5)	−0.0105 (5)	0.0007 (4)	0.0019 (4)
C21	0.0246 (4)	0.0261 (5)	0.0280 (5)	−0.0124 (4)	0.0090 (4)	−0.0016 (4)

O1—C14	1.2151 (11)	C15—H15A	0.9700
O2—C14	1.3412 (12)	C15—H15B	0.9700
O2—C15	1.4438 (12)	C16—H16A	0.9600
N1—C7	1.3178 (12)	C16—H16B	0.9600
N1—C8	1.3858 (11)	C16—H16C	0.9600
N2—C13	1.3817 (11)	C17—C19	1.5253 (18)
N2—C7	1.3895 (11)	C17—C18	1.5281 (19)
N2—C17	1.4733 (13)	C17—H17A	0.9800
N2—C17B	1.609 (10)	C18—H18A	0.9600
C1—C2	1.3886 (13)	C18—H18B	0.9600
C1—C6	1.3985 (13)	C18—H18C	0.9600
C1—H1A	0.9300	C19—C20	1.521 (2)
C2—C3	1.3952 (14)	C19—H19A	0.9700
C2—H2A	0.9300	C19—H19B	0.9700
C3—C4	1.3907 (14)	C20—H20A	0.9600
C3—C21	1.5051 (13)	C20—H20B	0.9600
C4—C5	1.3914 (13)	C20—H20C	0.9600
C4—H4A	0.9300	C17B—C18B	1.438 (16)
C5—C6	1.3969 (13)	C17B—C19B	1.512 (15)
C5—H5A	0.9300	C17B—H17B	0.9800
C6—C7	1.4720 (12)	C18B—H18D	0.9600
C8—C9	1.3935 (12)	C18B—H18E	0.9600
C8—C13	1.4101 (12)	C18B—H18F	0.9600
C9—C10	1.3926 (12)	C19B—C20B	1.656 (19)
C9—H9A	0.9300	C19B—H19C	0.9700
C10—C11	1.4083 (13)	C19B—H19D	0.9700
C10—C14	1.4842 (13)	C20B—H20D	0.9600
C11—C12	1.3851 (13)	C20B—H20E	0.9600
C11—H11A	0.9300	C20B—H20F	0.9600
C12—C13	1.4031 (12)	C21—H21A	0.9600
C12—H12A	0.9300	C21—H21B	0.9600
C15—C16	1.5047 (17)	C21—H21C	0.9600
C14—O2—C15	116.33 (8)	O2—C15—H15B	110.4
C7—N1—C8	104.38 (7)	C16—C15—H15B	110.4
C13—N2—C7	105.76 (7)	H15A—C15—H15B	108.6
C13—N2—C17	125.52 (8)	C15—C16—H16A	109.5
C7—N2—C17	125.91 (8)	C15—C16—H16B	109.5
C13—N2—C17B	122.2 (4)	H16A—C16—H16B	109.5
C7—N2—C17B	116.2 (4)	C15—C16—H16C	109.5
C2—C1—C6	120.28 (9)	H16A—C16—H16C	109.5
C2—C1—H1A	119.9	H16B—C16—H16C	109.5
C6—C1—H1A	119.9	N2—C17—C19	109.65 (10)
C1—C2—C3	121.07 (9)	N2—C17—C18	112.27 (11)
C1—C2—H2A	119.5	C19—C17—C18	113.46 (10)
C3—C2—H2A	119.5	N2—C17—H17A	107.0
C4—C3—C2	118.42 (8)	C19—C17—H17A	107.0
C4—C3—C21	121.15 (9)	C18—C17—H17A	107.0
C2—C3—C21	120.42 (10)	C20—C19—C17	112.18 (10)
C3—C4—C5	121.07 (9)	C20—C19—H19A	109.2
C3—C4—H4A	119.5	C17—C19—H19A	109.2
C5—C4—H4A	119.5	C20—C19—H19B	109.2
C4—C5—C6	120.29 (9)	C17—C19—H19B	109.2
C4—C5—H5A	119.9	H19A—C19—H19B	107.9
C6—C5—H5A	119.9	C18B—C17B—C19B	113.2 (9)
C5—C6—C1	118.86 (8)	C18B—C17B—N2	118.7 (8)
C5—C6—C7	119.27 (8)	C19B—C17B—N2	103.2 (8)
C1—C6—C7	121.71 (8)	C18B—C17B—H17B	107.0
N1—C7—N2	113.75 (7)	C19B—C17B—H17B	107.0
N1—C7—C6	122.96 (8)	N2—C17B—H17B	107.0
N2—C7—C6	123.17 (8)	C17B—C18B—H18D	109.5
N1—C8—C9	128.86 (8)	C17B—C18B—H18E	109.5
N1—C8—C13	110.60 (7)	H18D—C18B—H18E	109.5
C9—C8—C13	120.53 (8)	C17B—C18B—H18F	109.5
C10—C9—C8	117.86 (8)	H18D—C18B—H18F	109.5
C10—C9—H9A	121.1	H18E—C18B—H18F	109.5
C8—C9—H9A	121.1	C17B—C19B—C20B	115.8 (9)
C9—C10—C11	121.00 (8)	C17B—C19B—H19C	108.3
C9—C10—C14	120.69 (8)	C20B—C19B—H19C	108.3
C11—C10—C14	118.29 (8)	C17B—C19B—H19D	108.3
C12—C11—C10	122.07 (8)	C20B—C19B—H19D	108.3
C12—C11—H11A	119.0	H19C—C19B—H19D	107.4
C10—C11—H11A	119.0	C19B—C20B—H20D	109.5
C11—C12—C13	116.55 (8)	C19B—C20B—H20E	109.5
C11—C12—H12A	121.7	H20D—C20B—H20E	109.5
C13—C12—H12A	121.7	C19B—C20B—H20F	109.5
N2—C13—C12	132.51 (8)	H20D—C20B—H20F	109.5
N2—C13—C8	105.51 (7)	H20E—C20B—H20F	109.5
C12—C13—C8	121.98 (8)	C3—C21—H21A	109.5
O1—C14—O2	123.46 (9)	C3—C21—H21B	109.5
O1—C14—C10	124.68 (9)	H21A—C21—H21B	109.5
O2—C14—C10	111.86 (8)	C3—C21—H21C	109.5
O2—C15—C16	106.63 (8)	H21A—C21—H21C	109.5
O2—C15—H15A	110.4	H21B—C21—H21C	109.5
C16—C15—H15A	110.4
C6—C1—C2—C3	0.45 (15)	C17B—N2—C13—C12	44.5 (5)
C1—C2—C3—C4	−0.67 (14)	C7—N2—C13—C8	0.23 (10)
C1—C2—C3—C21	178.44 (9)	C17—N2—C13—C8	−161.60 (10)
C2—C3—C4—C5	0.58 (15)	C17B—N2—C13—C8	−135.9 (5)
C21—C3—C4—C5	−178.53 (9)	C11—C12—C13—N2	179.26 (10)
C3—C4—C5—C6	−0.26 (15)	C11—C12—C13—C8	−0.27 (14)
C4—C5—C6—C1	0.02 (14)	N1—C8—C13—N2	−0.09 (10)
C4—C5—C6—C7	175.50 (9)	C9—C8—C13—N2	−179.20 (8)
C2—C1—C6—C5	−0.12 (14)	N1—C8—C13—C12	179.55 (9)
C2—C1—C6—C7	−175.48 (9)	C9—C8—C13—C12	0.43 (14)
C8—N1—C7—N2	0.25 (10)	C15—O2—C14—O1	−1.73 (15)
C8—N1—C7—C6	−175.82 (8)	C15—O2—C14—C10	178.60 (8)
C13—N2—C7—N1	−0.31 (11)	C9—C10—C14—O1	174.76 (10)
C17—N2—C7—N1	161.42 (10)	C11—C10—C14—O1	−3.91 (15)
C17B—N2—C7—N1	138.9 (4)	C9—C10—C14—O2	−5.57 (13)
C13—N2—C7—C6	175.74 (9)	C11—C10—C14—O2	175.76 (8)
C17—N2—C7—C6	−22.52 (15)	C14—O2—C15—C16	170.62 (10)
C17B—N2—C7—C6	−45.1 (5)	C13—N2—C17—C19	51.97 (14)
C5—C6—C7—N1	−38.44 (13)	C7—N2—C17—C19	−106.28 (11)
C1—C6—C7—N1	136.90 (10)	C17B—N2—C17—C19	−36.7 (9)
C5—C6—C7—N2	145.86 (9)	C13—N2—C17—C18	−75.12 (14)
C1—C6—C7—N2	−38.79 (13)	C7—N2—C17—C18	126.63 (11)
C7—N1—C8—C9	178.93 (9)	C17B—N2—C17—C18	−163.7 (10)
C7—N1—C8—C13	−0.10 (10)	N2—C17—C19—C20	51.24 (13)
N1—C8—C9—C10	−179.49 (9)	C18—C17—C19—C20	177.66 (10)
C13—C8—C9—C10	−0.55 (13)	C13—N2—C17B—C18B	43.5 (10)
C8—C9—C10—C11	0.54 (14)	C7—N2—C17B—C18B	−88.4 (9)
C8—C9—C10—C14	−178.09 (8)	C17—N2—C17B—C18B	149.4 (15)
C9—C10—C11—C12	−0.41 (15)	C13—N2—C17B—C19B	−82.6 (7)
C14—C10—C11—C12	178.26 (9)	C7—N2—C17B—C19B	145.4 (5)
C10—C11—C12—C13	0.26 (14)	C17—N2—C17B—C19B	23.2 (7)
C7—N2—C13—C12	−179.36 (10)	C18B—C17B—C19B—C20B	178.5 (9)
C17—N2—C13—C12	18.81 (17)	N2—C17B—C19B—C20B	−51.9 (10)

Cg1 is centroid of the N1/C7/N2/C13/C8 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C12—H12A···O1i	0.93	2.58	3.5007 (13)	173
C20—H20C···Cg1	0.96	2.72	3.3432 (13)	123

Table 1

Hydrogen-bond geometry (Å, °)

Cg1 is centroid of the N1/C7/N2/C13/C8 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C12—H12A⋯O1i	0.93	2.58	3.5007 (13)	173
C20—H20C⋯Cg1	0.96	2.72	3.3432 (13)	123

Symmetry code: (i) .