organic compounds
6-Bromo-3-methyl-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 (UCCS), UMR 8181, 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
The title compound, C7H6BrN3O, was obtained from the reaction of 6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one with methyl iodide. All non-H atoms lie in a common plane [r.m.s deviation = 0.017 (1) Å]. The amino group is a hydrogen-bond donor to the carbonyl group of an inversion-related molecule, the pair of hydrogen bonds giving rise to a hydrogen-bonded dimer.
Related literature
For the synthesis of the title compound, see: Grivas & Lindström (1995); Smolyar et al. (2007).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; 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).
Supporting information
https://doi.org/10.1107/S1600536810012791/bt5243sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810012791/bt5243Isup2.hkl
6-Bromo-1H-imidazo[4,5-b]pyridine-2(3H)-thione (1 mmol), potassium carbonate (4 mmol), tetra-n-butylammonium bromide (0.1 mmol) and methyl iodide (2.5 mmol) in DMF (15 ml) were stirred for 48 hours. After completion of reaction (as monitored by TLC), the salt was filtered and the solvent removed under reduced pressure. The resulting residue was purified by
on silica gel using ethyl acetate/hexane (1/2) as Yellow crystals was isolated when the solvent was allowed to evaporate.Carbon-bound H atoms were placed in calculated positions (C—H = 0.93–0.96 Å) and were included in the
in the riding model approximation, with U(H) set to 1.2U(C). The amino H atom was located in a difference Fourier map, and was refined isotropically with a distance restraint of N—H = 0.86 (1) Å.6-Bromo-1H-imidazo[4,5-b]pyridine-2(3H)-one reacts with organic compounds to form pharmaceutical active compounds. It is easily methylated; in this study, it is methylated by methyl iodide under catalytic conditions. The mono N-methylated compound (Scheme I) is planar [r.m.s 0.017 (1) Å]. The amino group is hydrogen-bond donor to the carbonyl group of an inversion-related molecule to generate a hydrogen-bonded dimer (Fig. 1).
For the synthesis of the title compound, see: Grivas & Lindström (1995); Smolyar et al. (2007).
Data collection: APEX2 (Bruker, 2008); cell
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).Fig. 1. Anisotropic displacement ellipsoid plot (Barbour, 2001) of the title compound forming a centrosymmetric dimer at the 50% probability level; H atoms are drawn as spheres of arbitrary radii. |
C7H6BrN3O | Z = 2 |
Mr = 228.06 | F(000) = 224 |
Triclinic, P1 | Dx = 1.898 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 4.4151 (1) Å | Cell parameters from 2054 reflections |
b = 9.6004 (2) Å | θ = 2.4–24.1° |
c = 10.5330 (3) Å | µ = 5.10 mm−1 |
α = 116.248 (1)° | T = 293 K |
β = 93.074 (2)° | Prism, yellow |
γ = 91.687 (1)° | 0.36 × 0.17 × 0.10 mm |
V = 399.14 (2) Å3 |
Bruker X8 APEXII diffractometer | 1401 independent reflections |
Radiation source: fine-focus sealed tube | 1199 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.027 |
φ and ω scans | θmax = 24.9°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −5→4 |
Tmin = 0.478, Tmax = 0.630 | k = −11→11 |
4790 measured reflections | l = −12→12 |
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)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.077 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0493P)2 + 0.0118P] where P = (Fo2 + 2Fc2)/3 |
1401 reflections | (Δ/σ)max = 0.001 |
114 parameters | Δρmax = 0.52 e Å−3 |
1 restraint | Δρmin = −0.32 e Å−3 |
C7H6BrN3O | γ = 91.687 (1)° |
Mr = 228.06 | V = 399.14 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 4.4151 (1) Å | Mo Kα radiation |
b = 9.6004 (2) Å | µ = 5.10 mm−1 |
c = 10.5330 (3) Å | T = 293 K |
α = 116.248 (1)° | 0.36 × 0.17 × 0.10 mm |
β = 93.074 (2)° |
Bruker X8 APEXII diffractometer | 1401 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1199 reflections with I > 2σ(I) |
Tmin = 0.478, Tmax = 0.630 | Rint = 0.027 |
4790 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | 1 restraint |
wR(F2) = 0.077 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.52 e Å−3 |
1401 reflections | Δρmin = −0.32 e Å−3 |
114 parameters |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.91934 (8) | 0.96903 (4) | 0.29671 (4) | 0.04832 (17) | |
O1 | 0.0726 (5) | 0.3085 (3) | 0.3562 (3) | 0.0478 (6) | |
N1 | 0.7410 (6) | 0.4941 (3) | 0.1298 (3) | 0.0393 (6) | |
N2 | 0.4091 (6) | 0.3574 (3) | 0.2169 (3) | 0.0368 (6) | |
N3 | 0.2638 (6) | 0.5575 (3) | 0.4045 (3) | 0.0373 (6) | |
H3 | 0.165 (7) | 0.603 (4) | 0.478 (2) | 0.052 (11)* | |
C1 | 0.8436 (8) | 0.6389 (4) | 0.1562 (3) | 0.0395 (8) | |
H1 | 0.9737 | 0.6506 | 0.0946 | 0.047* | |
C2 | 0.7621 (7) | 0.7715 (4) | 0.2724 (3) | 0.0362 (7) | |
C3 | 0.5682 (7) | 0.7635 (3) | 0.3680 (3) | 0.0357 (7) | |
H3A | 0.5157 | 0.8517 | 0.4462 | 0.043* | |
C4 | 0.4584 (7) | 0.6171 (4) | 0.3399 (3) | 0.0332 (7) | |
C5 | 0.5521 (7) | 0.4890 (4) | 0.2200 (3) | 0.0326 (7) | |
C6 | 0.2306 (7) | 0.3988 (4) | 0.3293 (3) | 0.0359 (7) | |
C7 | 0.4409 (9) | 0.1982 (4) | 0.1123 (4) | 0.0532 (10) | |
H7A | 0.6141 | 0.1577 | 0.1406 | 0.080* | |
H7B | 0.4681 | 0.1960 | 0.0216 | 0.080* | |
H7C | 0.2613 | 0.1357 | 0.1055 | 0.080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0551 (3) | 0.0388 (2) | 0.0537 (3) | −0.00649 (16) | 0.00846 (17) | 0.02302 (18) |
O1 | 0.0560 (15) | 0.0356 (12) | 0.0502 (14) | −0.0057 (11) | 0.0173 (12) | 0.0168 (11) |
N1 | 0.0399 (15) | 0.0385 (15) | 0.0382 (15) | 0.0040 (12) | 0.0119 (12) | 0.0146 (13) |
N2 | 0.0420 (15) | 0.0298 (13) | 0.0356 (14) | 0.0018 (11) | 0.0087 (12) | 0.0112 (11) |
N3 | 0.0406 (16) | 0.0336 (14) | 0.0361 (15) | 0.0011 (12) | 0.0140 (13) | 0.0131 (12) |
C1 | 0.0404 (18) | 0.0410 (18) | 0.0380 (18) | 0.0024 (14) | 0.0119 (15) | 0.0175 (16) |
C2 | 0.0372 (17) | 0.0328 (16) | 0.0416 (19) | −0.0016 (13) | 0.0022 (15) | 0.0194 (15) |
C3 | 0.0367 (17) | 0.0305 (16) | 0.0381 (17) | 0.0040 (13) | 0.0074 (14) | 0.0131 (14) |
C4 | 0.0294 (16) | 0.0336 (16) | 0.0353 (17) | 0.0032 (13) | 0.0029 (13) | 0.0139 (14) |
C5 | 0.0305 (16) | 0.0308 (15) | 0.0344 (16) | 0.0030 (13) | 0.0015 (13) | 0.0126 (13) |
C6 | 0.0349 (17) | 0.0367 (17) | 0.0357 (17) | 0.0011 (14) | 0.0064 (14) | 0.0155 (14) |
C7 | 0.067 (3) | 0.0341 (18) | 0.049 (2) | 0.0033 (17) | 0.0166 (19) | 0.0079 (16) |
Br1—C2 | 1.902 (3) | C1—C2 | 1.394 (5) |
O1—C6 | 1.233 (4) | C1—H1 | 0.9300 |
N1—C5 | 1.313 (4) | C2—C3 | 1.382 (4) |
N1—C1 | 1.349 (4) | C3—C4 | 1.369 (4) |
N2—C6 | 1.373 (4) | C3—H3A | 0.9300 |
N2—C5 | 1.382 (4) | C4—C5 | 1.411 (4) |
N2—C7 | 1.452 (4) | C7—H7A | 0.9600 |
N3—C6 | 1.370 (4) | C7—H7B | 0.9600 |
N3—C4 | 1.381 (4) | C7—H7C | 0.9600 |
N3—H3 | 0.856 (10) | ||
C5—N1—C1 | 114.5 (3) | C3—C4—N3 | 134.7 (3) |
C6—N2—C5 | 109.8 (2) | C3—C4—C5 | 118.7 (3) |
C6—N2—C7 | 124.2 (3) | N3—C4—C5 | 106.6 (3) |
C5—N2—C7 | 126.1 (3) | N1—C5—N2 | 126.7 (3) |
C6—N3—C4 | 110.0 (3) | N1—C5—C4 | 126.5 (3) |
C6—N3—H3 | 119 (3) | N2—C5—C4 | 106.7 (3) |
C4—N3—H3 | 131 (3) | O1—C6—N3 | 127.3 (3) |
N1—C1—C2 | 122.5 (3) | O1—C6—N2 | 125.8 (3) |
N1—C1—H1 | 118.7 | N3—C6—N2 | 106.9 (3) |
C2—C1—H1 | 118.7 | N2—C7—H7A | 109.5 |
C3—C2—C1 | 122.1 (3) | N2—C7—H7B | 109.5 |
C3—C2—Br1 | 119.5 (2) | H7A—C7—H7B | 109.5 |
C1—C2—Br1 | 118.4 (2) | N2—C7—H7C | 109.5 |
C4—C3—C2 | 115.6 (3) | H7A—C7—H7C | 109.5 |
C4—C3—H3A | 122.2 | H7B—C7—H7C | 109.5 |
C2—C3—H3A | 122.2 | ||
C5—N1—C1—C2 | 1.8 (5) | C6—N2—C5—C4 | 0.2 (3) |
N1—C1—C2—C3 | −0.5 (5) | C7—N2—C5—C4 | −179.4 (3) |
N1—C1—C2—Br1 | −179.4 (2) | C3—C4—C5—N1 | 0.6 (5) |
C1—C2—C3—C4 | −0.9 (5) | N3—C4—C5—N1 | −179.2 (3) |
Br1—C2—C3—C4 | 178.0 (2) | C3—C4—C5—N2 | −179.9 (3) |
C2—C3—C4—N3 | −179.4 (3) | N3—C4—C5—N2 | 0.3 (3) |
C2—C3—C4—C5 | 0.8 (4) | C4—N3—C6—O1 | −179.5 (3) |
C6—N3—C4—C3 | 179.6 (3) | C4—N3—C6—N2 | 0.7 (4) |
C6—N3—C4—C5 | −0.6 (3) | C5—N2—C6—O1 | 179.7 (3) |
C1—N1—C5—N2 | 178.8 (3) | C7—N2—C6—O1 | −0.8 (5) |
C1—N1—C5—C4 | −1.9 (5) | C5—N2—C6—N3 | −0.5 (3) |
C6—N2—C5—N1 | 179.6 (3) | C7—N2—C6—N3 | 179.0 (3) |
C7—N2—C5—N1 | 0.1 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3···O1i | 0.86 (1) | 1.95 (1) | 2.804 (3) | 176 (4) |
Symmetry code: (i) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C7H6BrN3O |
Mr | 228.06 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 4.4151 (1), 9.6004 (2), 10.5330 (3) |
α, β, γ (°) | 116.248 (1), 93.074 (2), 91.687 (1) |
V (Å3) | 399.14 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 5.10 |
Crystal size (mm) | 0.36 × 0.17 × 0.10 |
Data collection | |
Diffractometer | Bruker X8 APEXII |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.478, 0.630 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4790, 1401, 1199 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.593 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.077, 1.05 |
No. of reflections | 1401 |
No. of parameters | 114 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.52, −0.32 |
Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
N3—H3···O1i | 0.86 (1) | 1.95 (1) | 2.804 (3) | 176 (4) |
Symmetry code: (i) −x, −y+1, −z+1. |
Acknowledgements
The authors thank the University Sidi Mohammed Ben Abdallah, the Université Mohammed V-Agdal and the University of Malaya for supporting this study.
References
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6-Bromo-1H-imidazo[4,5-b]pyridine-2(3H)-one reacts with organic compounds to form pharmaceutical active compounds. It is easily methylated; in this study, it is methylated by methyl iodide under catalytic conditions. The mono N-methylated compound (Scheme I) is planar [r.m.s 0.017 (1) Å]. The amino group is hydrogen-bond donor to the carbonyl group of an inversion-related molecule to generate a hydrogen-bonded dimer (Fig. 1).