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Acta Cryst. (2008). E64, o2262    [ doi:10.1107/S1600536808035393 ]

tert-Butyl N-(5-bromo-1H-imidazo[4,5-b]pyridin-2-ylmethyl)carbamate

L. Yin, J. Jia, G.-L. Zhao and J.-W. Wang

Abstract top

In the molecule of the title compound, C12H15BrN4O2, the imidazole and pyridine rings are strictly coplanar [maximum deviation 0.006 (3) Å]. In the crystal structure, molecules are linked into chains running parallel to the a axis by intermolecular N-H...O hydrogen bonds. Centrosymmetrically related chains are further connected by N-H...N hydrogen-bonding interactions to form a two-dimensional layer structure parallel to the ab plane.

Comment top

Nitrogen heterocyclic compounds and their derivatives are substances which show diverse biological activity (Dai et al., 2004). Among them, imidazo[4,5-b]pyridine compounds are an important class of imidazole derivatives, which are widely used in the field of medicine (Durant et al., 1973; Wang et al., 2007). As a continuation of our studies on this subject, the structure of the title compound is described herein.

In the molecule of the title compound (Fig. 1) the imidazole and pyridine rings are strictly coplanar, the maximum deviation from the mean plane of the two rings being 0.006 (3) Å for atom C4. The C6—N2 and C6—N3 bond lengths in the imidazole ring are 1.362 (3) and 1.310 (3) Å, respectively; the bond angles between non-hydrogen atoms of the pyridine ring are in the range 114.3 (2)–126.8 (2)°, which is in line with the values reported for similar compounds (Lorenc et al., 2008). In the crystal packing, intermolecular N—H···O hydrogen bonds involving the amide and carbonyl groups (Table 1) link adjacent molecules into chains parallel to the a axis. Centrosymmetrically related chains are further linked by intermolecular N—H···N hydrogen bonds to form a two-dimensional layer structure parallel to the ab plane (Fig. 2).

Related literature top

For general background on the properties of imidazole derivatives, see: Dai et al. (2004); Durant et al. (1973); Wang et al. (2007). For the crystal structures of related compounds, see: Lorenc et al. (2008).

Experimental top

5-Bromopyridine-2,3-diamine(3.7 g, 20 mmol) and N-(tert-butoxycarbonyl)glycine (3.5 g, 20 mmol) were dissolved in THF (40 ml) and cooled to 273 K. N,N'-Dicyclohexylcarbodiimide (4.94 g, 24 mmol) was then added in batches and the mixture was stirred at 273 K for half an hour and at room temperature overnight. The filtrate was evaporated to afford a green solid, which was dissolved in acetic acid (20 ml) and the solution was stirred at 353 K for 8 h. The acetic acid was removed under reduced pressure and the crude title compound was separated as a pale green solid. Crystals of the title compound suitable for X-ray analysis were obtained by slow evaporation at room temperature if a dichloromethane-methanol (6:1, v/v) solution (yield; 70%, m.p. 475–476 K).

Refinement top

H atoms bound to N atoms were located from a difference Fourier map and refined freely. All other H atoms were placed at calculated positions and included in the refinement in the riding-model approximation, with C—H = 0.93-0.98 Å and Uiso(H) = 1.2 Ueq(C) or 1.5 Ueq(C) for methylene and methyl H atoms.

Computing details top

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 30% probability level.
[Figure 2] Fig. 2. Crystal packing of the title compound viewed along the a axis. Intermolecular hydrogen bonds are shown as dashed lines.
tert-Butyl N-(5-bromo-1H-imidazo[4,5-b]pyridin-2-ylmethyl)carbamate top
Crystal data top
C12H15BrN4O2F(000) = 1328
Mr = 327.19Dx = 1.483 Mg m−3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 4297 reflections
a = 10.7400 (11) Åθ = 2.4–24.9°
b = 9.6717 (9) ŵ = 2.81 mm−1
c = 28.215 (3) ÅT = 298 K
V = 2930.8 (5) Å3Plate, colourless
Z = 80.20 × 0.10 × 0.05 mm
Data collection top
Bruker SMART APEX area-detector
diffractometer		3374 independent reflections
Radiation source: fine-focus sealed tube2285 reflections with I > 2σ(I)
graphiteRint = 0.031
φ and ω scansθmax = 27.6°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Bruker, 2002)		h = −13→13
Tmin = 0.604, Tmax = 0.872k = −12→8
16102 measured reflectionsl = −36→29
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)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.102H atoms treated by a mixture of independent and constrained refinement
S = 1.01 w = 1/[σ2(Fo2) + (0.0412P)2 + 2.0629P]
where P = (Fo2 + 2Fc2)/3
3374 reflections(Δ/σ)max = 0.001
180 parametersΔρmax = 0.72 e Å−3
0 restraintsΔρmin = −0.65 e Å−3
Crystal data top
C12H15BrN4O2V = 2930.8 (5) Å3
Mr = 327.19Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 10.7400 (11) ŵ = 2.81 mm−1
b = 9.6717 (9) ÅT = 298 K
c = 28.215 (3) Å0.20 × 0.10 × 0.05 mm
Data collection top
Bruker SMART APEX area-detector
diffractometer		3374 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2002)		2285 reflections with I > 2σ(I)
Tmin = 0.604, Tmax = 0.872Rint = 0.031
16102 measured reflectionsθmax = 27.6°
Refinement top
R[F2 > 2σ(F2)] = 0.038H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.102Δρmax = 0.72 e Å−3
S = 1.01Δρmin = −0.65 e Å−3
3374 reflectionsAbsolute structure: ?
180 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.13230 (4)0.06577 (4)0.356022 (12)0.07448 (16)
O10.2545 (2)0.37496 (19)0.61523 (7)0.0588 (5)
O20.1723 (2)0.55519 (18)0.65633 (7)0.0532 (5)
N10.0365 (2)0.3710 (2)0.45039 (8)0.0492 (5)
N20.1726 (2)0.4846 (2)0.50653 (8)0.0425 (5)
N30.35221 (19)0.3775 (2)0.48963 (8)0.0481 (5)
N40.2808 (2)0.5942 (2)0.59153 (8)0.0441 (5)
C10.0386 (3)0.2736 (3)0.41650 (10)0.0508 (7)
H1−0.03500.25290.40060.061*
C20.1457 (3)0.2029 (3)0.40420 (9)0.0488 (6)
C30.2584 (3)0.2271 (3)0.42539 (9)0.0499 (6)
H30.33010.17950.41670.060*
C40.2590 (2)0.3268 (3)0.46047 (8)0.0426 (6)
C50.1455 (2)0.3930 (3)0.47101 (9)0.0395 (5)
C60.2964 (2)0.4704 (3)0.51590 (9)0.0414 (6)
C70.3610 (2)0.5565 (3)0.55229 (10)0.0463 (6)
H7A0.43200.50560.56440.056*
H7B0.39200.64000.53740.056*
C80.2370 (2)0.4976 (3)0.62088 (9)0.0411 (6)
C90.1098 (3)0.4696 (3)0.69213 (10)0.0563 (7)
C100.2031 (4)0.3846 (5)0.71874 (13)0.0989 (13)
H10A0.23890.31720.69780.148*
H10B0.16250.33840.74460.148*
H10C0.26750.44360.73080.148*
C110.0119 (4)0.3815 (5)0.66859 (16)0.1005 (14)
H11A0.05150.31310.64910.151*
H11B−0.04060.43890.64930.151*
H11C−0.03750.33660.69240.151*
C120.0497 (4)0.5769 (4)0.72365 (14)0.0929 (13)
H12A0.11320.63150.73860.139*
H12B0.00050.53170.74740.139*
H12C−0.00270.63580.70490.139*
H20.124 (3)0.537 (3)0.5189 (11)0.051 (9)*
H3A0.272 (2)0.678 (3)0.5990 (8)0.034 (7)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0908 (3)0.0764 (3)0.0563 (2)0.00984 (19)0.00153 (17)−0.02719 (16)
O10.0800 (14)0.0302 (10)0.0660 (12)0.0025 (9)0.0186 (11)−0.0051 (9)
O20.0700 (13)0.0381 (10)0.0516 (11)0.0002 (9)0.0197 (9)−0.0059 (8)
N10.0436 (12)0.0482 (13)0.0559 (14)0.0046 (10)−0.0002 (10)−0.0114 (11)
N20.0382 (12)0.0406 (12)0.0488 (13)0.0050 (10)0.0065 (10)−0.0055 (10)
N30.0387 (11)0.0575 (14)0.0482 (12)0.0069 (10)0.0078 (10)−0.0079 (11)
N40.0540 (14)0.0259 (11)0.0524 (13)−0.0004 (9)0.0092 (10)−0.0055 (9)
C10.0515 (16)0.0472 (16)0.0539 (16)0.0033 (13)−0.0026 (13)−0.0078 (13)
C20.0593 (17)0.0493 (15)0.0379 (13)0.0037 (13)0.0066 (12)−0.0044 (11)
C30.0513 (16)0.0556 (16)0.0427 (14)0.0107 (13)0.0110 (12)−0.0047 (12)
C40.0414 (13)0.0478 (15)0.0385 (12)0.0051 (11)0.0104 (11)0.0005 (11)
C50.0417 (13)0.0368 (13)0.0401 (13)0.0018 (11)0.0069 (11)−0.0008 (10)
C60.0391 (13)0.0430 (14)0.0420 (14)−0.0003 (11)0.0083 (11)0.0012 (11)
C70.0411 (13)0.0492 (15)0.0486 (15)−0.0048 (12)0.0061 (12)−0.0017 (12)
C80.0457 (14)0.0332 (13)0.0445 (13)−0.0005 (11)0.0024 (11)−0.0051 (11)
C90.0630 (18)0.0561 (17)0.0499 (16)−0.0051 (14)0.0154 (14)−0.0002 (13)
C100.109 (3)0.124 (3)0.064 (2)0.021 (3)0.009 (2)0.025 (2)
C110.085 (3)0.115 (3)0.101 (3)−0.044 (3)0.024 (2)−0.015 (3)
C120.109 (3)0.093 (3)0.077 (2)0.001 (2)0.045 (2)−0.012 (2)
Geometric parameters (Å, °) top
Br1—C21.904 (3)C3—H30.9300
O1—C81.211 (3)C4—C51.409 (3)
O2—C81.339 (3)C6—C71.493 (4)
O2—C91.469 (3)C7—H7A0.9700
N1—C51.325 (3)C7—H7B0.9700
N1—C11.342 (3)C9—C101.498 (5)
N2—C61.362 (3)C9—C111.507 (5)
N2—C51.369 (3)C9—C121.512 (4)
N2—H20.81 (3)C10—H10A0.9600
N3—C61.310 (3)C10—H10B0.9600
N3—C41.385 (3)C10—H10C0.9600
N4—C81.335 (3)C11—H11A0.9600
N4—C71.449 (3)C11—H11B0.9600
N4—H3A0.84 (3)C11—H11C0.9600
C1—C21.383 (4)C12—H12A0.9600
C1—H10.9300C12—H12B0.9600
C2—C31.370 (4)C12—H12C0.9600
C3—C41.382 (3)
C8—O2—C9121.1 (2)N4—C7—H7B109.0
C5—N1—C1114.3 (2)C6—C7—H7B109.0
C6—N2—C5106.5 (2)H7A—C7—H7B107.8
C6—N2—H2128 (2)O1—C8—N4123.3 (2)
C5—N2—H2126 (2)O1—C8—O2125.9 (2)
C6—N3—C4104.4 (2)N4—C8—O2110.8 (2)
C8—N4—C7120.4 (2)O2—C9—C10110.4 (3)
C8—N4—H3A118.5 (17)O2—C9—C11109.5 (3)
C7—N4—H3A120.2 (17)C10—C9—C11112.1 (3)
N1—C1—C2122.6 (3)O2—C9—C12102.3 (2)
N1—C1—H1118.7C10—C9—C12111.6 (3)
C2—C1—H1118.7C11—C9—C12110.5 (3)
C3—C2—C1122.8 (2)C9—C10—H10A109.5
C3—C2—Br1119.8 (2)C9—C10—H10B109.5
C1—C2—Br1117.4 (2)H10A—C10—H10B109.5
C2—C3—C4115.9 (2)C9—C10—H10C109.5
C2—C3—H3122.1H10A—C10—H10C109.5
C4—C3—H3122.1H10B—C10—H10C109.5
C3—C4—N3132.5 (2)C9—C11—H11A109.5
C3—C4—C5117.7 (2)C9—C11—H11B109.5
N3—C4—C5109.8 (2)H11A—C11—H11B109.5
N1—C5—N2127.9 (2)C9—C11—H11C109.5
N1—C5—C4126.8 (2)H11A—C11—H11C109.5
N2—C5—C4105.4 (2)H11B—C11—H11C109.5
N3—C6—N2114.0 (2)C9—C12—H12A109.5
N3—C6—C7124.0 (2)C9—C12—H12B109.5
N2—C6—C7122.1 (2)H12A—C12—H12B109.5
N4—C7—C6113.0 (2)C9—C12—H12C109.5
N4—C7—H7A109.0H12A—C12—H12C109.5
C6—C7—H7A109.0H12B—C12—H12C109.5
C5—N1—C1—C2−0.2 (4)N3—C4—C5—N20.5 (3)
N1—C1—C2—C3−0.4 (4)C4—N3—C6—N20.4 (3)
N1—C1—C2—Br1179.1 (2)C4—N3—C6—C7−178.3 (2)
C1—C2—C3—C40.5 (4)C5—N2—C6—N3−0.1 (3)
Br1—C2—C3—C4−178.99 (19)C5—N2—C6—C7178.7 (2)
C2—C3—C4—N3179.1 (3)C8—N4—C7—C665.8 (3)
C2—C3—C4—C50.0 (4)N3—C6—C7—N4−149.7 (2)
C6—N3—C4—C3−179.6 (3)N2—C6—C7—N431.7 (3)
C6—N3—C4—C5−0.5 (3)C7—N4—C8—O1−4.5 (4)
C1—N1—C5—N2−179.8 (3)C7—N4—C8—O2175.7 (2)
C1—N1—C5—C40.7 (4)C9—O2—C8—O1−2.6 (4)
C6—N2—C5—N1−179.8 (3)C9—O2—C8—N4177.2 (2)
C6—N2—C5—C4−0.3 (3)C8—O2—C9—C1061.7 (4)
C3—C4—C5—N1−0.7 (4)C8—O2—C9—C11−62.3 (4)
N3—C4—C5—N1−179.9 (2)C8—O2—C9—C12−179.5 (3)
C3—C4—C5—N2179.8 (2)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H2···N1i0.81 (3)2.12 (3)2.911 (3)165 (3)
N4—H3A···O1ii0.84 (3)1.98 (3)2.822 (3)178 (2)
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1/2, y+1/2, z.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H2···N1i0.81 (3)2.12 (3)2.911 (3)165 (3)
N4—H3A···O1ii0.84 (3)1.98 (3)2.822 (3)178 (2)
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1/2, y+1/2, z.
Acknowledgements top

The authors thank the National Basic Research Priority Program for the Science Fund grant No. 2003CCA027.

references
References top

Bruker (2002). SADABS, SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.

Dai, G. Y., Liu, D. L., Wang, S. H. & Liu, Y. (2004). Chin. J. Org. Chem. 24, 315–318.

Durant, G. J., Loynes, J. M. & Wright, S. H. B. (1973). J. Med. Chem. 16, 1272–1276.

Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.

Lorenc, J., Dyminska, L., Talik, Z., Hanuza, J., Maczka, M., Waskowska, A. & Macalik, L. (2008). J. Raman Spectrosc. 39, 1–15.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Wang, L. B., Pan, J., Tang, C. L., Jiang, D. W., Qiu, F., Bu, X. R. & Wang, J. (2007). Chin. J. Org. Chem. 27, 1573–1576.