organic compounds
4-Benzyl-6-bromo-2-(4-chlorophenyl)-4H-imidazo[4,5-b]pyridine
aLaboratoire de Chimie Organique Appliquée, Faculté des Sciences et Techniques, Université Sidi Mohammed Ben Abdellah, Fès, Morocco, bDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA, and cLaboratoire de Chimie Organique Hétérocyclique URAC 21, Pôle de Compétence Pharmacochimie, Av. Ibn Battouta, BP 1014, Faculté des Sciences, Université Mohammed V, Rabat, Morocco
*Correspondence e-mail: bourichiselma@hotmail.com
In the title compound, C19H13BrClN3, the chlorophenyl ring occupies an equatorial position with respect to the mean plane of the imidazopyridine unit, while the other phenyl ring is twisted by 4.1 (2)° with respect to the mean plane of the imidazopyridine unit. In the crystal, pairwise C—H⋯Br interactions link the molecules into dimers, forming an R22(16) ring motif. In addition, weak π–π stacking interactions stabilize the crystal packing.
Keywords: crystal structure; imidazo[4,5-b]pyridine; hydrogen bonding.
CCDC reference: 1556392
Structure description
Imidazopyridine derivatives display anticancer (Lukasik et al., 2012), tuberculostatic (Bukowski & Janowiec, 1989) and antimitotic activities (Aridoss et al., 2006). This study is a continuation of our work (Bourichi et al., 2016; Ouzidan et al., 2010) on the syntheses and structures of new imidazopyridine derivatives.
The title compound, C19H13BrClN3, crystallizes with one molecule in the (Fig. 1). The imidazo[4,5-b]pyridine unit is essentially planar (r.m.s. deviation = 0.010 Å). The chlorophenyl ring occupies an equatorial position with respect to the mean plane of the imidazopyridine unit, with a dihedral angle of 4.1 (2)°. The other phenyl ring is twisted with respect to the mean plane of the imidazopyridine unit by 72.2 (3)°.
In the crystal, pairwise C19—H19⋯Br1 interactions link the molecules into inversion dimers, forming an R22(16) ring motif (Table 1 and Fig. 2). In addition, weak π–π stacking interactions stabilize the crystal packing [Cg1⋯Cg2i = 3.858 (2) Å; symmetry code: (i) −x + 1, −y + 1, −z + 1; Cg1 is the centroid of ring N2/C4/C6/N3/C5 and Cg2 of ring N1/C1/C2/C3/C4/C6].
Synthesis and crystallization
A mixture of 0.2 g (0.65 mmol) of 6-bromo-2-(4-chlorophenyl)-3H-imidazo[4,5-b]pyridine, dissolved in 25 ml of DMF, and 0.13 g (0.92 mmol) of potassium carbonate was stirred magnetically for 5 min and then 0.032 g (0.1 mmol) of tetra-n-butylammonium bromide (TBAB) and 0.094 g (0.78 mmol) of benzyl bromide were added. Stirring was continued at room temperature for 24 h. After removing the salts by filtration, the DMF was evaporated under reduced pressure and the residue obtained was dissolved in dichloromethane. The remaining salts were extracted with distilled water and the resulting mixture was chromatographed on a silica-gel column (eluent: ethyl acetate–hexane, 1:3 v/v). Yellow crystals were isolated when the solvent was allowed to evaporate (yield 65%; m.p. 464–465 K).
Refinement
Crystal data, data collection and structure . All H atoms were placed in calculated positions and refined using the riding model, with C—H bond lengths of 0.93 (CH) or 0.97 Å (CH2). Isotropic displacement parameters for these atoms were set at 1.2 times Ueq of the parent atom.
details are summarized in Table 2Structural data
CCDC reference: 1556392
https://doi.org/10.1107/S2414314617008999/vm4023sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617008999/vm4023Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314617008999/vm4023Isup3.cdx
Supporting information file. DOI: https://doi.org/10.1107/S2414314617008999/vm4023Isup4.cml
Data collection: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); cell
CrysAlis PRO (Rigaku Oxford Diffraction, 2015); data reduction: CrysAlis PRO (Rigaku Oxford Diffraction, 2015); program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).C19H13BrClN3 | Z = 2 |
Mr = 398.68 | F(000) = 400 |
Triclinic, P1 | Dx = 1.633 Mg m−3 |
a = 8.7749 (7) Å | Cu Kα radiation, λ = 1.54184 Å |
b = 9.9403 (7) Å | Cell parameters from 2096 reflections |
c = 10.4475 (8) Å | θ = 4.6–71.2° |
α = 76.030 (6)° | µ = 5.00 mm−1 |
β = 66.511 (7)° | T = 293 K |
γ = 85.843 (6)° | Irregular, yellow |
V = 810.76 (12) Å3 | 0.14 × 0.12 × 0.06 mm |
Rigaku Oxford Diffraction diffractometer | 3076 independent reflections |
Radiation source: fine-focus sealed X-ray tube, Enhance (Cu) X-ray Source | 2637 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 16.0416 pixels mm-1 | θmax = 71.3°, θmin = 4.6° |
ω scans | h = −6→10 |
Absorption correction: multi-scan (CrysAlis PRO; Rigaku Oxford Diffraction, 2015) | k = −11→12 |
Tmin = 0.393, Tmax = 1.000 | l = −12→12 |
5047 measured reflections |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.044 | w = 1/[σ2(Fo2) + (0.0674P)2 + 0.2037P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.124 | (Δ/σ)max = 0.001 |
S = 1.04 | Δρmax = 0.64 e Å−3 |
3076 reflections | Δρmin = −0.60 e Å−3 |
218 parameters | Extinction correction: SHELXT2014 (Sheldrick, 2015a), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0012 (4) |
Primary atom site location: dual |
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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.20904 (4) | 0.05758 (4) | 0.60405 (4) | 0.04964 (18) | |
Cl1 | 0.40328 (14) | 1.29736 (10) | 0.10620 (12) | 0.0608 (3) | |
N1 | 0.5634 (3) | 0.3647 (3) | 0.3684 (3) | 0.0384 (6) | |
N2 | 0.2447 (3) | 0.6063 (3) | 0.3757 (3) | 0.0384 (6) | |
N3 | 0.5333 (3) | 0.6100 (3) | 0.2869 (3) | 0.0391 (6) | |
C1 | 0.4801 (4) | 0.2417 (3) | 0.4415 (3) | 0.0393 (7) | |
H1 | 0.5392 | 0.1616 | 0.4542 | 0.047* | |
C2 | 0.3102 (4) | 0.2344 (3) | 0.4964 (4) | 0.0401 (7) | |
C3 | 0.2119 (4) | 0.3497 (3) | 0.4823 (4) | 0.0393 (7) | |
H3 | 0.0964 | 0.3427 | 0.5206 | 0.047* | |
C4 | 0.2966 (4) | 0.4739 (4) | 0.4081 (3) | 0.0373 (7) | |
C5 | 0.3881 (4) | 0.6806 (3) | 0.3058 (3) | 0.0373 (7) | |
C6 | 0.4742 (4) | 0.4804 (3) | 0.3519 (3) | 0.0357 (6) | |
C7 | 0.3929 (4) | 0.8314 (4) | 0.2557 (4) | 0.0385 (7) | |
C8 | 0.2453 (4) | 0.9043 (4) | 0.2807 (4) | 0.0486 (8) | |
H8 | 0.1438 | 0.8561 | 0.3283 | 0.058* | |
C9 | 0.2486 (5) | 1.0471 (4) | 0.2356 (4) | 0.0511 (9) | |
H9 | 0.1500 | 1.0950 | 0.2533 | 0.061* | |
C10 | 0.3991 (5) | 1.1173 (3) | 0.1645 (4) | 0.0425 (7) | |
C11 | 0.5467 (4) | 1.0485 (4) | 0.1389 (4) | 0.0497 (9) | |
H11 | 0.6477 | 1.0977 | 0.0919 | 0.060* | |
C12 | 0.5431 (4) | 0.9057 (4) | 0.1838 (4) | 0.0470 (8) | |
H12 | 0.6424 | 0.8588 | 0.1657 | 0.056* | |
C13 | 0.7474 (4) | 0.3741 (4) | 0.3102 (4) | 0.0416 (7) | |
H13A | 0.7865 | 0.3112 | 0.3768 | 0.050* | |
H13B | 0.7822 | 0.4675 | 0.3013 | 0.050* | |
C14 | 0.8254 (3) | 0.3382 (3) | 0.1653 (4) | 0.0362 (7) | |
C15 | 0.8029 (4) | 0.4197 (4) | 0.0478 (4) | 0.0500 (8) | |
H15 | 0.7384 | 0.4981 | 0.0560 | 0.060* | |
C16 | 0.8781 (5) | 0.3832 (6) | −0.0831 (4) | 0.0649 (12) | |
H16 | 0.8628 | 0.4348 | −0.1639 | 0.078* | |
C17 | 0.9753 (6) | 0.2690 (6) | −0.0899 (5) | 0.0676 (12) | |
H17 | 1.0290 | 0.2421 | −0.1762 | 0.081* | |
C18 | 0.9923 (5) | 0.1951 (5) | 0.0320 (5) | 0.0649 (12) | |
H18 | 1.0594 | 0.1181 | 0.0258 | 0.078* | |
C19 | 0.9186 (4) | 0.2268 (3) | 0.1588 (3) | 0.0369 (7) | |
H19 | 0.9319 | 0.1732 | 0.2398 | 0.044* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0423 (2) | 0.0371 (2) | 0.0573 (3) | 0.00609 (15) | −0.01030 (17) | −0.00689 (16) |
Cl1 | 0.0740 (6) | 0.0384 (5) | 0.0712 (7) | 0.0027 (4) | −0.0354 (5) | −0.0031 (4) |
N1 | 0.0338 (13) | 0.0426 (15) | 0.0375 (14) | 0.0121 (11) | −0.0121 (11) | −0.0132 (12) |
N2 | 0.0331 (12) | 0.0376 (14) | 0.0392 (14) | 0.0080 (11) | −0.0108 (11) | −0.0075 (11) |
N3 | 0.0323 (13) | 0.0410 (15) | 0.0403 (15) | 0.0071 (11) | −0.0104 (11) | −0.0111 (12) |
C1 | 0.0416 (16) | 0.0368 (16) | 0.0355 (16) | 0.0104 (13) | −0.0116 (14) | −0.0101 (13) |
C2 | 0.0442 (17) | 0.0325 (15) | 0.0380 (17) | 0.0062 (13) | −0.0114 (14) | −0.0078 (13) |
C3 | 0.0321 (14) | 0.0392 (17) | 0.0393 (17) | 0.0061 (12) | −0.0083 (13) | −0.0074 (13) |
C4 | 0.0335 (15) | 0.0411 (17) | 0.0335 (16) | 0.0107 (13) | −0.0097 (13) | −0.0109 (13) |
C5 | 0.0354 (15) | 0.0400 (17) | 0.0349 (16) | 0.0080 (13) | −0.0127 (13) | −0.0097 (13) |
C6 | 0.0352 (15) | 0.0372 (16) | 0.0322 (15) | 0.0109 (12) | −0.0107 (13) | −0.0113 (12) |
C7 | 0.0367 (15) | 0.0403 (17) | 0.0389 (17) | 0.0064 (13) | −0.0156 (13) | −0.0101 (13) |
C8 | 0.0329 (15) | 0.0441 (19) | 0.059 (2) | 0.0048 (14) | −0.0119 (15) | −0.0061 (16) |
C9 | 0.0436 (18) | 0.047 (2) | 0.058 (2) | 0.0119 (15) | −0.0194 (17) | −0.0081 (17) |
C10 | 0.0523 (19) | 0.0358 (17) | 0.0424 (18) | 0.0033 (14) | −0.0244 (16) | −0.0051 (14) |
C11 | 0.0402 (17) | 0.047 (2) | 0.057 (2) | −0.0028 (15) | −0.0185 (16) | −0.0052 (17) |
C12 | 0.0346 (16) | 0.050 (2) | 0.051 (2) | 0.0062 (14) | −0.0153 (15) | −0.0060 (16) |
C13 | 0.0309 (15) | 0.052 (2) | 0.0420 (18) | 0.0125 (14) | −0.0123 (14) | −0.0186 (15) |
C14 | 0.0241 (12) | 0.0405 (17) | 0.0393 (17) | 0.0001 (12) | −0.0074 (12) | −0.0094 (13) |
C15 | 0.0413 (17) | 0.058 (2) | 0.048 (2) | 0.0093 (16) | −0.0183 (16) | −0.0084 (17) |
C16 | 0.052 (2) | 0.098 (3) | 0.039 (2) | −0.002 (2) | −0.0152 (17) | −0.009 (2) |
C17 | 0.056 (2) | 0.090 (3) | 0.045 (2) | −0.005 (2) | 0.0007 (19) | −0.029 (2) |
C18 | 0.052 (2) | 0.065 (3) | 0.064 (3) | 0.013 (2) | −0.004 (2) | −0.025 (2) |
C19 | 0.0307 (13) | 0.0339 (15) | 0.0349 (16) | 0.0091 (12) | −0.0038 (12) | −0.0061 (12) |
Br1—C2 | 1.902 (3) | C9—H9 | 0.9300 |
Cl1—C10 | 1.744 (3) | C9—C10 | 1.373 (5) |
N1—C1 | 1.359 (4) | C10—C11 | 1.379 (5) |
N1—C6 | 1.359 (4) | C11—H11 | 0.9300 |
N1—C13 | 1.482 (4) | C11—C12 | 1.382 (5) |
N2—C4 | 1.370 (4) | C12—H12 | 0.9300 |
N2—C5 | 1.343 (4) | C13—H13A | 0.9700 |
N3—C5 | 1.376 (4) | C13—H13B | 0.9700 |
N3—C6 | 1.336 (4) | C13—C14 | 1.512 (4) |
C1—H1 | 0.9300 | C14—C15 | 1.376 (5) |
C1—C2 | 1.367 (5) | C14—C19 | 1.326 (4) |
C2—C3 | 1.399 (4) | C15—H15 | 0.9300 |
C3—H3 | 0.9300 | C15—C16 | 1.387 (6) |
C3—C4 | 1.375 (5) | C16—H16 | 0.9300 |
C4—C6 | 1.429 (4) | C16—C17 | 1.367 (7) |
C5—C7 | 1.461 (5) | C17—H17 | 0.9300 |
C7—C8 | 1.398 (4) | C17—C18 | 1.367 (7) |
C7—C12 | 1.390 (5) | C18—H18 | 0.9300 |
C8—H8 | 0.9300 | C18—C19 | 1.328 (5) |
C8—C9 | 1.382 (5) | C19—H19 | 0.9300 |
C1—N1—C13 | 121.2 (3) | C9—C10—C11 | 121.4 (3) |
C6—N1—C1 | 118.5 (3) | C11—C10—Cl1 | 119.4 (3) |
C6—N1—C13 | 120.3 (3) | C10—C11—H11 | 120.4 |
C5—N2—C4 | 103.0 (3) | C10—C11—C12 | 119.3 (3) |
C6—N3—C5 | 100.9 (3) | C12—C11—H11 | 120.4 |
N1—C1—H1 | 119.6 | C7—C12—H12 | 119.6 |
N1—C1—C2 | 120.7 (3) | C11—C12—C7 | 120.8 (3) |
C2—C1—H1 | 119.6 | C11—C12—H12 | 119.6 |
C1—C2—Br1 | 116.4 (3) | N1—C13—H13A | 109.3 |
C1—C2—C3 | 123.3 (3) | N1—C13—H13B | 109.3 |
C3—C2—Br1 | 120.2 (3) | N1—C13—C14 | 111.8 (3) |
C2—C3—H3 | 122.1 | H13A—C13—H13B | 107.9 |
C4—C3—C2 | 115.8 (3) | C14—C13—H13A | 109.3 |
C4—C3—H3 | 122.1 | C14—C13—H13B | 109.3 |
N2—C4—C3 | 132.5 (3) | C15—C14—C13 | 121.1 (3) |
N2—C4—C6 | 107.1 (3) | C19—C14—C13 | 116.0 (3) |
C3—C4—C6 | 120.4 (3) | C19—C14—C15 | 122.9 (3) |
N2—C5—N3 | 117.5 (3) | C14—C15—H15 | 120.5 |
N2—C5—C7 | 122.3 (3) | C14—C15—C16 | 118.9 (4) |
N3—C5—C7 | 120.2 (3) | C16—C15—H15 | 120.5 |
N1—C6—C4 | 121.3 (3) | C15—C16—H16 | 121.0 |
N3—C6—N1 | 127.2 (3) | C17—C16—C15 | 118.1 (4) |
N3—C6—C4 | 111.5 (3) | C17—C16—H16 | 121.0 |
C8—C7—C5 | 120.4 (3) | C16—C17—H17 | 120.5 |
C12—C7—C5 | 121.1 (3) | C18—C17—C16 | 119.0 (4) |
C12—C7—C8 | 118.5 (3) | C18—C17—H17 | 120.5 |
C7—C8—H8 | 119.6 | C17—C18—H18 | 118.1 |
C9—C8—C7 | 120.8 (3) | C19—C18—C17 | 123.8 (4) |
C9—C8—H8 | 119.6 | C19—C18—H18 | 118.1 |
C8—C9—H9 | 120.4 | C14—C19—C18 | 117.3 (4) |
C10—C9—C8 | 119.2 (3) | C14—C19—H19 | 121.4 |
C10—C9—H9 | 120.4 | C18—C19—H19 | 121.4 |
C9—C10—Cl1 | 119.2 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C19—H19···Br1i | 0.93 | 2.54 | 3.202 (3) | 128 |
Symmetry code: (i) −x+1, −y, −z+1. |
Acknowledgements
JPJ acknowledges the NSF–MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.
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