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

Abstract

In the mol-ecule of the title compound, C(12)H(15)BrN(4)O(2), the imidazole and pyridine rings are strictly coplanar [maximum deviation 0.006 (3) Å]. In the crystal structure, mol-ecules are linked into chains running parallel to the a axis by inter-molecular N-H⋯O hydrogen bonds. Centrosymmetrically related chains are further connected by N-H⋯N hydrogen-bonding inter-actions to form a two-dimensional layer structure parallel to the ab plane.

Full text

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tert-Butyl N-(5-bromo-1H-imidazo[4,5-
b]pyridin-2-ylmethyl)carbamate
Ling Yin,aJiong Jia,a* Gui-Long Zhaoband Jian-Wu Wanga
aSchool of Chemistry and Chemical Engineering, Shandong University, Jinan
250100, People’s Republic of China, andbThe Pharmaceutical Research Institute of
Tianjin, Tianjin 300193, People’s Republic of China
Correspondence e-mail: jwwang@sdu.edu.cn
Received 21 October 2008; accepted 29 October 2008
Key indicators: single-crystal X-ray study; T = 298 K; mean ?(C–C) = 0.004 A ˚;
R factor = 0.038; wR factor = 0.102; data-to-parameter ratio = 18.7.
In the molecule of the title compound, C12H15BrN4O2, the
imidazole and pyridine rings are strictly coplanar [maximum
deviation 0.006 (3) A˚]. In the crystal structure, molecules are
linked into chains running parallel to the a axis by inter-
molecular 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.
Related literature
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
Crystal data
C12H15BrN4O2
Mr= 327.19
Orthorhombic, Pbca
a = 10.7400 (11) A˚
b = 9.6717 (9) A˚
c = 28.215 (3) A˚
V = 2930.8 (5) A˚3
Z = 8
Mo K? radiation
? = 2.81 mm?1
T = 298 (2) K
0.20 ? 0.10 ? 0.05 mm
Data collection
Bruker SMART APEX area-
detector diffractometer
Absorption correction: multi-scan
(SADABS; Bruker, 2002)
Tmin= 0.604, Tmax= 0.872
16102 measured reflections
3374 independent reflections
2285 reflections with I > 2?(I)
Rint= 0.031
Refinement
R[F2> 2?(F2)] = 0.038
wR(F2) = 0.102
S = 1.01
3374 reflections
180 parameters
H atoms treated by a mixture of
independent and constrained
refinement
??max= 0.72 e A˚?3
??min= ?0.65 e A˚?3
Table 1
Hydrogen-bond geometry (A˚,?).
D—H???A
N2—H2???N1i
N4—H3A???O1ii
Symmetry codes: (i) ?x;?y þ 1;?z þ 1; (ii) ?x þ1
D—HH???AD???AD—H???A
0.81 (3)
0.84 (3)
2.12 (3)
1.98 (3)
2.911 (3)
2.822 (3)
165 (3)
178 (2)
2;y þ1
2;z.
Data collection: SMART (Bruker, 2002); cell refinement: SAINT
(Bruker, 2002); data reduction: SAINT; program(s) used to solve
structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine
structure: SHELXL97(Sheldrick,
ORTEP-3 for Windows (Farrugia, 1997); software used to prepare
material for publication: SHELXL97.
2008); moleculargraphics:
The authors thank the National Basic Research Priority
Program for the Science Fund grant No. 2003CCA027.
Supplementary data and figures for this paper are available from the
IUCr electronic archives (Reference: RZ2259).
References
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.
organic compounds
o2262
Yin et al.
doi:10.1107/S1600536808035393
Acta Cryst. (2008). E64, o2262
Acta Crystallographica Section E
Structure Reports
Online
ISSN 1600-5368

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supplementary materials

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supplementary materials
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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
Comment
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).
Experimental
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
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.
Figures
Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at
the 30% probability level.

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Fig. 2. Crystal packing of the title compound viewed along the a axis. Intermolecular hydro-
gen bonds are shown as dashed lines.
tert-Butyl N-(5-bromo-1H-imidazo[4,5-b]pyridin-2-ylmethyl)carbamate
Crystal data
C12H15BrN4O2
F000 = 1328
Dx = 1.483 Mg m−3
Mo Kα radiation
λ = 0.71073 Å
Cell parameters from 4297 reflections
θ = 2.4–24.9º
µ = 2.81 mm−1
T = 298 (2) K
Mr = 327.19
Orthorhombic, Pbca
Hall symbol: -P 2ac 2ab
a = 10.7400 (11) Å
b = 9.6717 (9) Å
c = 28.215 (3) Å
V = 2930.8 (5) Å3
Z = 8
Plate, colourless
0.20 × 0.10 × 0.05 mm
Data collection
Bruker SMART APEX area-detector
diffractometer
Radiation source: fine-focus sealed tube
Monochromator: graphite
T = 298(2) K
φ and ω scans
Absorption correction: multi-scan
(SADABS; Bruker, 2002)
Tmin = 0.604, Tmax = 0.872
16102 measured reflections
3374 independent reflections
2285 reflections with I > 2σ(I)
Rint = 0.031
θmax = 27.6º
θmin = 2.4º
h = −13→13
k = −12→8
l = −36→29
Refinement
Refinement on F2
Secondary atom site location: difference Fourier map
Least-squares matrix: full
Hydrogen site location: inferred from neighbouring
sites
H atoms treated by a mixture of
independent and constrained refinement
w = 1/[σ2(Fo2) + (0.0412P)2 + 2.0629P]
where P = (Fo2 + 2Fc2)/3
(Δ/σ)max = 0.001
Δρmax = 0.72 e Å−3
Δρmin = −0.65 e Å−3
R[F2 > 2σ(F2)] = 0.038
wR(F2) = 0.102
S = 1.01
3374 reflections
180 parameters

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supplementary materials
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Primary atom site location: structure-invariant direct
methods
Extinction correction: none
Special details
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 mat-
rix. 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, convention-
al 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)
x
0.13230 (4)
0.2545 (2)
0.1723 (2)
0.0365 (2)
0.1726 (2)
0.35221 (19)
0.2808 (2)
0.0386 (3)
−0.0350
0.1457 (3)
0.2584 (3)
0.3301
0.2590 (2)
0.1455 (2)
0.2964 (2)
0.3610 (2)
0.4320
0.3920
0.2370 (2)
0.1098 (3)
0.2031 (4)
0.2389
0.1625
0.2675
0.0119 (4)
0.0515
−0.0406
−0.0375
0.0497 (4)
0.1132
0.0005
y
0.06577 (4)
0.37496 (19)
0.55519 (18)
0.3710 (2)
0.4846 (2)
0.3775 (2)
0.5942 (2)
0.2736 (3)
0.2529
0.2029 (3)
0.2271 (3)
0.1795
0.3268 (3)
0.3930 (3)
0.4704 (3)
0.5565 (3)
0.5056
0.6400
0.4976 (3)
0.4696 (3)
0.3846 (5)
0.3172
0.3384
0.4436
0.3815 (5)
0.3131
0.4389
0.3366
0.5769 (4)
0.6315
0.5317
z
0.356022 (12)
0.61523 (7)
0.65633 (7)
0.45039 (8)
0.50653 (8)
0.48963 (8)
0.59153 (8)
0.41650 (10)
0.4006
0.40420 (9)
0.42539 (9)
0.4167
0.46047 (8)
0.47101 (9)
0.51590 (9)
0.55229 (10)
0.5644
0.5374
0.62088 (9)
0.69213 (10)
0.71874 (13)
0.6978
0.7446
0.7308
0.66859 (16)
0.6491
0.6493
0.6924
0.72365 (14)
0.7386
0.7474
Uiso*/Ueq
0.07448 (16)
0.0588 (5)
0.0532 (5)
0.0492 (5)
0.0425 (5)
0.0481 (5)
0.0441 (5)
0.0508 (7)
0.061*
0.0488 (6)
0.0499 (6)
0.060*
0.0426 (6)
0.0395 (5)
0.0414 (6)
0.0463 (6)
0.056*
0.056*
0.0411 (6)
0.0563 (7)
0.0989 (13)
0.148*
0.148*
0.148*
0.1005 (14)
0.151*
0.151*
0.151*
0.0929 (13)
0.139*
0.139*
Br1
O1
O2
N1
N2
N3
N4
C1
H1
C2
C3
H3
C4
C5
C6
C7
H7A
H7B
C8
C9
C10
H10A
H10B
H10C
C11
H11A
H11B
H11C
C12
H12A
H12B