organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

1,3-Di­benzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one

aLaboratoire de Chimie Organique Appliquée, Faculté des Sciences et Techniques, Université Sidi Mohamed Ben Abdallah, Fés, Morocco, bUnité de Catalyse et de Chimie du Solide, Ecole Nationale Supérieure de Chimie de Lille, Lille, France, cLaboratoire de Chimie Organique Hétérocyclique, Pôle de Compétences Pharmacochimie, Université Mohammed V-Agdal, BP 1014 Avenue Ibn Batout, Rabat, Morocco, and dDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: seikweng@um.edu.my

(Received 24 February 2010; accepted 1 March 2010; online 6 March 2010)

The imidazopyridine fused-ring in the title compound, C20H16BrN3O, is planar (r.m.s. deviation = 0.011 Å). The phenyl rings of the benzyl substitutents twist away from the central five-membered ring in opposite directions; the rings are aligned at 61.3 (1) and 71.2 (1)° with respect to this ring.

Related literature

For the medicinal applications of 1,3-dihydro-imidazo[4,5-b]pyridin-2-ones, see: Barraclough et al. (1990[Barraclough, P., Black, J. W., Cambridge, D., Collard, D., Firmin, D., Gerskowitch, V. P., Glen, R. C., Giles, H. & Hill, A. P. (1990). J. Med. Chem. 33, 2231-2239.]); Cundy et al. (1997[Cundy, D. J., Holan, G., Otaegui, M. & Simpson, G. W. (1997). Bioorg. Med. Chem. Lett. 7, 669-674.]); Desarro et al. (1994[Desarro, A., Desarro, G., Chimirri, A., Grasso, S., Monforte, A. M. & Zappala, M. (1994). Gen. Pharmacol. 25,1027-1031.]); Liu et al. (2008[Liu, L., Xu, P., Zhou, L. & Lei, P. S. (2008). Chin. Chem. Lett. 19, 1-4.]); Mader et al. (2008[Mader, M., de Dios, A., Shih, C., Bonjouklian, R., Li, T. C., White, W., de Uralde, B. L., Sánchez-Martinez, C., del Prado, M., Jaramillo, C., de Diego, E., Cabrejas, L. M. M., Dominguez, C., Montero, C., Shepherd, T., Dally, R., Toth, J. E., Chatterjee, A., Pleite, S., Blanco-Urgoiti, J., Perez, L., Barberis, M., Lorite, M. J., Jambrina, E., Nevill, C. R., Lee, P. A., Schultz, R. C., Wolos, J. A., Li, L. C., Campbell, R. M. & Anderson, B. D. (2008). Bioorg. Med. Chem. Lett. 18, 179-183.]); Zaki & Proença (2007[Zaki, M. E. A. & Proença, M. F. (2007). Tetrahedron, 63, 3745-3753.]). For the product of the reaction of propargyl bromide with 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one in DMF at room and high temperatures, see: Dahmani et al. (2010a[Dahmani, S., Haoudi, A., Capet, F., Essassi, E. M. & Ng, S. W. (2010a). Acta Cryst. E66, o755.],b[Dahmani, S., Haoudi, A., Capet, F., Essassi, E. M. & Ng, S. W. (2010b). Acta Cryst. E66, o756.]).

[Scheme 1]

Experimental

Crystal data
  • C20H16BrN3O

  • Mr = 394.27

  • Monoclinic, P 21 /c

  • a = 9.1627 (1) Å

  • b = 25.5071 (3) Å

  • c = 8.0629 (1) Å

  • β = 115.571 (1)°

  • V = 1699.84 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 2.43 mm−1

  • T = 293 K

  • 0.42 × 0.18 × 0.13 mm

Data collection
  • Bruker X8 APEX2 diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.428, Tmax = 0.743

  • 38010 measured reflections

  • 3903 independent reflections

  • 2967 reflections with I > 2σ(I)

  • Rint = 0.036

Refinement
  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.138

  • S = 1.07

  • 3903 reflections

  • 226 parameters

  • H-atom parameters constrained

  • Δρmax = 0.84 e Å−3

  • Δρmin = −0.90 e Å−3

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: X-SEED (Barbour, 2001[Barbour, L. J. (2001). J. Supramol. Chem. 1, 189-191.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). publCIF. In preparation.]).

Supporting information


Comment top

Imidazo[4,5-b]pyridines are precursors for the synthesis of a variety of medicinal agents as compounds having the imidazo[4,5-b]pyridine fused-ring system possess a broad range of pharmacological activities (Barraclough et al., 1990; Cundy et al., 1997; Desarro et al., 1994; Liu et al., 2008; Mader et al., 2008; Zaki & Proença, 2007).

The present study represents the synthesis of the substituted an imidazo[4,5-b]pyridin-2-one derivative by the direct action of benzyl chloride on 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one in boiling DMF.

The imidazopyridine fused-ring in C20H16BrN3O (Scheme I, Fig. 1) is planar (r.m.s. deviation 0.011 Å). The phenyl rings of the benzyl substitutents twist away from the central five-membered ring in opposite directions; the rings are aligned at 61.3 (1) and 71.2 (1) ° with respect to this ring.

The temperature of the reaction, in the case of propargyl bromide, governs the nature of the product (Dahmani et al., 2010a, 2010b).

Related literature top

For the medicinal applications of 1,3-dihydro-imidazo[4,5-b]pyridin-2-ones, see: Barraclough et al. (1990); Cundy et al. (1997); Desarro et al. (1994); Liu et al. (2008); Mader et al. (2008); Zaki & Proença (2007). For the product of the reaction of propargyl bromide with 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one in DMF at room and high temperatures, see: Dahmani et al. (2010a,b).

Experimental top

To a mixture of 6-bromo-1,3-dihydro-imidazo[4,5-b]pyridin-2-one (1 mmol), potassium carbonate (4 mmol) and benzyltributylammonium chloride (0.1 mmol) in DMF was added benzyl chloride (2.5 mmol). The mixture was stirred for 48 hours. After completion of reaction (monitored by TLC), the inorganic salt was filtered and the solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel with ethyl acetate/hexane (1/1) as eluent. Colorless crystals were isolated when the solvent was allowed to evaporate.

Refinement top

Carbon-bound H-atoms were placed in calculated positions (C—H 0.93-0.97 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U(C).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C20H16BrN3O at the 50% probability level; hydrogen atoms are drawn as arbitrary radius.
1,3-Dibenzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one top
Crystal data top
C20H16BrN3OF(000) = 800
Mr = 394.27Dx = 1.541 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 9890 reflections
a = 9.1627 (1) Åθ = 2.5–25.0°
b = 25.5071 (3) ŵ = 2.43 mm1
c = 8.0629 (1) ÅT = 293 K
β = 115.571 (1)°Prism, colorless
V = 1699.84 (3) Å30.42 × 0.18 × 0.13 mm
Z = 4
Data collection top
Bruker X8 APEX2
diffractometer
3903 independent reflections
Radiation source: fine-focus sealed tube2967 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.036
ϕ and ω scansθmax = 27.5°, θmin = 1.6°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1111
Tmin = 0.428, Tmax = 0.743k = 3333
38010 measured reflectionsl = 910
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.138H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0688P)2 + 1.1691P]
where P = (Fo2 + 2Fc2)/3
3903 reflections(Δ/σ)max = 0.001
226 parametersΔρmax = 0.84 e Å3
0 restraintsΔρmin = 0.90 e Å3
Crystal data top
C20H16BrN3OV = 1699.84 (3) Å3
Mr = 394.27Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.1627 (1) ŵ = 2.43 mm1
b = 25.5071 (3) ÅT = 293 K
c = 8.0629 (1) Å0.42 × 0.18 × 0.13 mm
β = 115.571 (1)°
Data collection top
Bruker X8 APEX2
diffractometer
3903 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2967 reflections with I > 2σ(I)
Tmin = 0.428, Tmax = 0.743Rint = 0.036
38010 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.138H-atom parameters constrained
S = 1.07Δρmax = 0.84 e Å3
3903 reflectionsΔρmin = 0.90 e Å3
226 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.75465 (4)0.225888 (14)0.48173 (6)0.07328 (18)
O10.2072 (3)0.45942 (8)0.3332 (3)0.0570 (5)
N10.3210 (3)0.28134 (9)0.4493 (3)0.0480 (6)
N20.2208 (3)0.36984 (9)0.3920 (3)0.0399 (5)
N30.4318 (3)0.40833 (8)0.3767 (3)0.0398 (5)
C10.4498 (4)0.25184 (12)0.4685 (4)0.0515 (7)
H10.44650.21600.48790.062*
C20.5858 (4)0.27231 (11)0.4606 (4)0.0473 (7)
C30.6008 (3)0.32553 (11)0.4321 (4)0.0428 (6)
H30.69260.33960.42750.051*
C40.4695 (3)0.35553 (10)0.4115 (3)0.0366 (5)
C50.3351 (3)0.33129 (10)0.4207 (3)0.0366 (5)
C60.2777 (3)0.41774 (10)0.3635 (4)0.0401 (6)
C70.0593 (3)0.36191 (13)0.3822 (4)0.0482 (7)
H7A0.02260.32690.33560.058*
H7B0.01450.38670.29520.058*
C80.0513 (3)0.36830 (10)0.5637 (4)0.0376 (5)
C90.0052 (3)0.41597 (11)0.6102 (4)0.0448 (6)
H90.01620.44440.53100.054*
C100.0090 (4)0.42129 (13)0.7723 (4)0.0530 (7)
H100.03990.45330.80230.064*
C110.0223 (4)0.37940 (15)0.8905 (4)0.0572 (8)
H110.01050.38290.99890.069*
C120.0711 (4)0.33231 (14)0.8480 (5)0.0581 (8)
H120.09460.30420.92910.070*
C130.0854 (3)0.32658 (12)0.6849 (4)0.0490 (7)
H130.11800.29460.65650.059*
C140.5321 (4)0.44829 (11)0.3487 (4)0.0431 (6)
H14A0.63490.44980.45700.052*
H14B0.47970.48210.33620.052*
C150.5641 (3)0.43916 (9)0.1821 (3)0.0349 (5)
C160.6900 (3)0.46603 (11)0.1695 (4)0.0437 (6)
H160.75260.48890.26300.052*
C170.7240 (4)0.45935 (14)0.0203 (4)0.0549 (8)
H170.80920.47770.01370.066*
C180.6319 (4)0.42548 (13)0.1197 (4)0.0533 (7)
H180.65590.42040.21940.064*
C190.5046 (4)0.39937 (12)0.1105 (4)0.0498 (7)
H190.44110.37700.20550.060*
C200.4702 (3)0.40613 (11)0.0401 (4)0.0445 (6)
H200.38360.38840.04530.053*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0600 (2)0.0554 (2)0.0961 (3)0.01808 (15)0.0259 (2)0.00089 (17)
O10.0630 (13)0.0486 (12)0.0681 (14)0.0147 (10)0.0364 (11)0.0062 (10)
N10.0528 (14)0.0437 (13)0.0526 (14)0.0072 (10)0.0274 (12)0.0003 (10)
N20.0410 (11)0.0455 (12)0.0394 (12)0.0017 (9)0.0233 (10)0.0020 (9)
N30.0454 (12)0.0371 (11)0.0455 (12)0.0015 (9)0.0277 (10)0.0009 (9)
C10.0595 (18)0.0372 (15)0.0584 (18)0.0029 (13)0.0261 (15)0.0018 (13)
C20.0459 (15)0.0424 (15)0.0494 (16)0.0071 (12)0.0166 (13)0.0007 (12)
C30.0398 (13)0.0436 (14)0.0478 (15)0.0001 (11)0.0214 (12)0.0026 (12)
C40.0424 (13)0.0371 (12)0.0336 (12)0.0029 (10)0.0194 (11)0.0028 (10)
C50.0392 (13)0.0400 (13)0.0336 (12)0.0026 (10)0.0186 (10)0.0031 (10)
C60.0482 (15)0.0438 (14)0.0346 (13)0.0014 (12)0.0239 (11)0.0020 (11)
C70.0359 (13)0.0663 (19)0.0426 (15)0.0056 (12)0.0172 (12)0.0081 (13)
C80.0291 (11)0.0463 (14)0.0404 (13)0.0053 (10)0.0177 (10)0.0025 (11)
C90.0402 (14)0.0445 (15)0.0506 (16)0.0020 (11)0.0204 (12)0.0050 (12)
C100.0482 (16)0.0594 (18)0.0570 (18)0.0009 (14)0.0279 (14)0.0135 (15)
C110.0468 (16)0.090 (2)0.0415 (16)0.0001 (16)0.0251 (13)0.0038 (16)
C120.0531 (18)0.069 (2)0.0566 (19)0.0009 (15)0.0276 (15)0.0177 (16)
C130.0460 (15)0.0441 (15)0.0637 (18)0.0007 (12)0.0302 (14)0.0014 (13)
C140.0544 (16)0.0379 (13)0.0447 (15)0.0103 (12)0.0287 (13)0.0057 (11)
C150.0382 (12)0.0309 (12)0.0383 (13)0.0023 (10)0.0190 (11)0.0031 (10)
C160.0412 (14)0.0442 (15)0.0437 (15)0.0059 (11)0.0166 (12)0.0001 (11)
C170.0486 (17)0.066 (2)0.0605 (19)0.0051 (14)0.0338 (16)0.0068 (15)
C180.0600 (18)0.0642 (19)0.0467 (16)0.0081 (15)0.0333 (15)0.0053 (14)
C190.0571 (17)0.0519 (16)0.0401 (15)0.0015 (13)0.0206 (13)0.0074 (12)
C200.0460 (15)0.0461 (15)0.0463 (15)0.0085 (12)0.0245 (13)0.0048 (12)
Geometric parameters (Å, º) top
Br1—C21.897 (3)C9—H90.9300
O1—C61.213 (3)C10—C111.377 (5)
N1—C51.311 (3)C10—H100.9300
N1—C11.351 (4)C11—C121.376 (5)
N2—C51.382 (3)C11—H110.9300
N2—C61.386 (3)C12—C131.384 (5)
N2—C71.462 (3)C12—H120.9300
N3—C41.389 (3)C13—H130.9300
N3—C61.391 (3)C14—C151.512 (4)
N3—C141.453 (3)C14—H14A0.9700
C1—C21.377 (4)C14—H14B0.9700
C1—H10.9300C15—C201.382 (4)
C2—C31.393 (4)C15—C161.383 (4)
C3—C41.374 (4)C16—C171.377 (4)
C3—H30.9300C16—H160.9300
C4—C51.408 (4)C17—C181.382 (5)
C7—C81.505 (4)C17—H170.9300
C7—H7A0.9700C18—C191.372 (5)
C7—H7B0.9700C18—H180.9300
C8—C131.386 (4)C19—C201.391 (4)
C8—C91.390 (4)C19—H190.9300
C9—C101.376 (4)C20—H200.9300
C5—N1—C1114.4 (2)C9—C10—C11120.3 (3)
C5—N2—C6110.0 (2)C9—C10—H10119.9
C5—N2—C7126.0 (2)C11—C10—H10119.9
C6—N2—C7123.9 (2)C12—C11—C10119.9 (3)
C4—N3—C6109.8 (2)C12—C11—H11120.1
C4—N3—C14126.4 (2)C10—C11—H11120.1
C6—N3—C14123.8 (2)C11—C12—C13120.2 (3)
N1—C1—C2123.1 (3)C11—C12—H12119.9
N1—C1—H1118.4C13—C12—H12119.9
C2—C1—H1118.4C12—C13—C8120.2 (3)
C1—C2—C3122.2 (3)C12—C13—H13119.9
C1—C2—Br1118.6 (2)C8—C13—H13119.9
C3—C2—Br1119.2 (2)N3—C14—C15114.1 (2)
C4—C3—C2114.8 (3)N3—C14—H14A108.7
C4—C3—H3122.6C15—C14—H14A108.7
C2—C3—H3122.6N3—C14—H14B108.7
C3—C4—N3133.9 (2)C15—C14—H14B108.7
C3—C4—C5119.3 (2)H14A—C14—H14B107.6
N3—C4—C5106.9 (2)C20—C15—C16118.8 (2)
N1—C5—N2126.6 (2)C20—C15—C14122.7 (2)
N1—C5—C4126.2 (3)C16—C15—C14118.5 (2)
N2—C5—C4107.2 (2)C17—C16—C15120.9 (3)
O1—C6—N2126.9 (3)C17—C16—H16119.6
O1—C6—N3127.0 (3)C15—C16—H16119.6
N2—C6—N3106.1 (2)C16—C17—C18120.1 (3)
N2—C7—C8113.9 (2)C16—C17—H17120.0
N2—C7—H7A108.8C18—C17—H17120.0
C8—C7—H7A108.8C19—C18—C17119.6 (3)
N2—C7—H7B108.8C19—C18—H18120.2
C8—C7—H7B108.8C17—C18—H18120.2
H7A—C7—H7B107.7C18—C19—C20120.3 (3)
C13—C8—C9118.9 (2)C18—C19—H19119.8
C13—C8—C7120.7 (3)C20—C19—H19119.8
C9—C8—C7120.3 (3)C15—C20—C19120.3 (3)
C10—C9—C8120.4 (3)C15—C20—H20119.9
C10—C9—H9119.8C19—C20—H20119.9
C8—C9—H9119.8
C5—N1—C1—C20.6 (4)C4—N3—C6—N20.4 (3)
N1—C1—C2—C30.0 (5)C14—N3—C6—N2177.7 (2)
N1—C1—C2—Br1178.0 (2)C5—N2—C7—C892.2 (3)
C1—C2—C3—C40.4 (4)C6—N2—C7—C891.5 (3)
Br1—C2—C3—C4177.6 (2)N2—C7—C8—C1386.0 (3)
C2—C3—C4—N3178.0 (3)N2—C7—C8—C995.7 (3)
C2—C3—C4—C50.1 (4)C13—C8—C9—C101.1 (4)
C6—N3—C4—C3178.2 (3)C7—C8—C9—C10177.2 (3)
C14—N3—C4—C30.9 (5)C8—C9—C10—C110.0 (4)
C6—N3—C4—C50.1 (3)C9—C10—C11—C121.3 (5)
C14—N3—C4—C5177.4 (2)C10—C11—C12—C131.4 (5)
C1—N1—C5—N2178.3 (3)C11—C12—C13—C80.3 (5)
C1—N1—C5—C41.0 (4)C9—C8—C13—C121.0 (4)
C6—N2—C5—N1178.9 (3)C7—C8—C13—C12177.3 (3)
C7—N2—C5—N12.1 (4)C4—N3—C14—C1562.6 (4)
C6—N2—C5—C40.5 (3)C6—N3—C14—C15114.3 (3)
C7—N2—C5—C4177.3 (2)N3—C14—C15—C2018.6 (4)
C3—C4—C5—N10.6 (4)N3—C14—C15—C16163.1 (2)
N3—C4—C5—N1179.2 (3)C20—C15—C16—C171.3 (4)
C3—C4—C5—N2178.8 (2)C14—C15—C16—C17179.7 (3)
N3—C4—C5—N20.2 (3)C15—C16—C17—C180.1 (5)
C5—N2—C6—O1179.4 (3)C16—C17—C18—C191.2 (5)
C7—N2—C6—O12.6 (4)C17—C18—C19—C201.2 (5)
C5—N2—C6—N30.5 (3)C16—C15—C20—C191.4 (4)
C7—N2—C6—N3177.4 (2)C14—C15—C20—C19179.7 (3)
C4—N3—C6—O1179.6 (3)C18—C19—C20—C150.1 (5)
C14—N3—C6—O12.2 (4)

Experimental details

Crystal data
Chemical formulaC20H16BrN3O
Mr394.27
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)9.1627 (1), 25.5071 (3), 8.0629 (1)
β (°) 115.571 (1)
V3)1699.84 (3)
Z4
Radiation typeMo Kα
µ (mm1)2.43
Crystal size (mm)0.42 × 0.18 × 0.13
Data collection
DiffractometerBruker X8 APEX2
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.428, 0.743
No. of measured, independent and
observed [I > 2σ(I)] reflections
38010, 3903, 2967
Rint0.036
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.138, 1.07
No. of reflections3903
No. of parameters226
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.84, 0.90

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).

 

Acknowledgements

We thank Université Sidi Mohammed Ben Abdallah, Université Mohammed V-Agdal and the University of Malaya for supporting this study.

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