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

In the mol-ecule of the title compound, C(9)H(8)BrN(3)O, the fused-ring system is almost planar, the largest deviation from the mean plane being 0.008 (3) Å. The plane through the atoms forming the allyl group is roughly perpendicular to the imidazo[4,5-b]pyridin-2-one system, as indicated by the dihedral angle between them of 70.28 (11)°. In the crystal, each mol-ecule is linked to its symmetry equivalent about the center of inversion by a pair of strong N-H⋯O hydrogen bond, forming inversion dimers.

Related literature

For background to the biological activity of imidazopyridines, see: Chen & Dost (1992 ▶); Cappelli et al. (2006 ▶); Weier et al. (1993 ▶, 1994 ▶); Kulkarni & Newman (2007 ▶). For background to their pharmacological activity, see: Bavetsias et al. (2007 ▶, 2010 ▶).

Experimental

Crystal data

C9H8BrN3O

M = 254.09

Triclinic,

a = 4.5138 (5) Å

b = 9.7750 (9) Å

c = 11.5717 (11) Å

α = 78.748 (2)°

β = 82.526 (3)°

γ = 86.038 (2)°

V = 496.00 (9) Å3

Z = 2

Mo Kα radiation

μ = 4.11 mm−1

T = 571 K

0.60 × 0.19 × 0.04 mm

Data collection

Bruker CCD three-circle diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.192, T max = 0.850

3086 measured reflections

2019 independent reflections

1683 reflections with I > 2σ(I)

R int = 0.026

Refinement

R[F 2 > 2σ(F 2)] = 0.046

wR(F 2) = 0.127

S = 1.09

2019 reflections

127 parameters

H-atom parameters constrained

Δρmax = 0.89 e Å−3

Δρmin = −0.82 e Å−3

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; 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: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811025037/sj5172sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811025037/sj5172Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811025037/sj5172Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C9H8BrN3O	Z = 2
Mr = 254.09	F(000) = 252
Triclinic, P1	Dx = 1.701 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.5138 (5) Å	Cell parameters from 2019 reflections
b = 9.7750 (9) Å	θ = 1.8–26.4°
c = 11.5717 (11) Å	µ = 4.11 mm−1
α = 78.748 (2)°	T = 571 K
β = 82.526 (3)°	Fiber, colourless
γ = 86.038 (2)°	0.60 × 0.19 × 0.04 mm
V = 496.00 (9) Å3

Bruker CCD three-circle diffractometer	2019 independent reflections
Radiation source: fine-focus sealed tube	1683 reflections with I > 2σ(I)
graphite	Rint = 0.026
ω scans	θmax = 26.4°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→5
Tmin = 0.192, Tmax = 0.850	k = −12→11
3086 measured reflections	l = −12→14

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.127	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0649P)2 + 0.1269P] where P = (Fo2 + 2Fc2)/3
2019 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.89 e Å−3
0 restraints	Δρmin = −0.82 e Å−3

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.

	x	y	z	Uiso*/Ueq
Br1	0.99854 (9)	−0.03225 (4)	0.83292 (4)	0.0624 (2)
N1	0.3023 (6)	0.4132 (3)	0.9218 (3)	0.0429 (6)
H1	0.1781	0.3823	0.9827	0.052*
C1	0.3081 (8)	0.5487 (4)	0.8627 (3)	0.0438 (7)
O1	0.1416 (6)	0.6472 (3)	0.8854 (2)	0.0545 (6)
N2	0.5408 (7)	0.5549 (3)	0.7722 (3)	0.0463 (7)
C2	0.6765 (8)	0.4238 (4)	0.7739 (3)	0.0448 (8)
N3	0.9047 (7)	0.3902 (3)	0.7003 (3)	0.0536 (7)
C3	0.9924 (8)	0.2536 (4)	0.7221 (4)	0.0537 (9)
H3	1.1527	0.2227	0.6733	0.064*
C4	0.8551 (8)	0.1578 (4)	0.8137 (3)	0.0474 (8)
C5	0.6169 (8)	0.1954 (3)	0.8914 (3)	0.0446 (7)
H5	0.5260	0.1316	0.9541	0.054*
C6	0.5261 (7)	0.3327 (3)	0.8692 (3)	0.0400 (7)
C7	0.6297 (9)	0.6836 (4)	0.6904 (4)	0.0577 (10)
H7A	0.8450	0.6793	0.6698	0.069*
H7B	0.5786	0.7622	0.7302	0.069*
C8	0.4822 (12)	0.7071 (5)	0.5791 (4)	0.0727 (13)
H8	0.4856	0.6330	0.5393	0.087*
C9	0.3510 (13)	0.8229 (7)	0.5349 (5)	0.0923 (17)
H9A	0.3435	0.8991	0.5725	0.111*
H9B	0.2637	0.8304	0.4653	0.111*

	U11	U22	U33	U12	U13	U23
Br1	0.0653 (3)	0.0414 (3)	0.0810 (4)	0.01520 (18)	−0.0026 (2)	−0.0228 (2)
N1	0.0438 (15)	0.0317 (14)	0.0475 (15)	0.0066 (11)	0.0071 (11)	−0.0044 (11)
C1	0.0459 (18)	0.0326 (17)	0.0504 (19)	0.0017 (14)	−0.0002 (14)	−0.0063 (14)
O1	0.0569 (15)	0.0348 (13)	0.0660 (16)	0.0104 (11)	0.0037 (12)	−0.0068 (11)
N2	0.0450 (15)	0.0336 (14)	0.0549 (17)	0.0030 (12)	0.0027 (13)	−0.0028 (12)
C2	0.0404 (17)	0.0413 (18)	0.0519 (19)	0.0003 (14)	−0.0030 (14)	−0.0091 (15)
N3	0.0468 (16)	0.0506 (18)	0.0585 (18)	0.0027 (13)	0.0070 (13)	−0.0084 (14)
C3	0.0443 (19)	0.056 (2)	0.060 (2)	0.0073 (16)	0.0025 (16)	−0.0189 (18)
C4	0.0459 (18)	0.0427 (18)	0.056 (2)	0.0057 (14)	−0.0047 (15)	−0.0181 (15)
C5	0.0457 (18)	0.0352 (17)	0.0512 (19)	0.0023 (14)	−0.0001 (14)	−0.0089 (14)
C6	0.0383 (16)	0.0344 (16)	0.0464 (18)	0.0013 (13)	−0.0010 (13)	−0.0095 (13)
C7	0.051 (2)	0.042 (2)	0.072 (2)	−0.0067 (16)	0.0028 (18)	0.0043 (17)
C8	0.101 (4)	0.058 (3)	0.051 (2)	−0.010 (2)	0.009 (2)	0.000 (2)
C9	0.094 (4)	0.102 (5)	0.068 (3)	−0.005 (3)	−0.007 (3)	0.014 (3)

Br1—C4	1.905 (4)	C3—H3	0.9300
N1—C1	1.367 (4)	C4—C5	1.387 (5)
N1—C6	1.388 (4)	C5—C6	1.361 (5)
N1—H1	0.8600	C5—H5	0.9300
C1—O1	1.228 (4)	C7—C8	1.498 (7)
C1—N2	1.379 (5)	C7—H7A	0.9700
N2—C2	1.380 (5)	C7—H7B	0.9700
N2—C7	1.465 (5)	C8—C9	1.286 (8)
C2—N3	1.315 (5)	C8—H8	0.9300
C2—C6	1.406 (5)	C9—H9A	0.9300
N3—C3	1.351 (5)	C9—H9B	0.9300
C3—C4	1.381 (6)
C1—N1—C6	110.1 (3)	C6—C5—C4	115.0 (3)
C1—N1—H1	124.9	C6—C5—H5	122.5
C6—N1—H1	124.9	C4—C5—H5	122.5
O1—C1—N1	127.3 (3)	C5—C6—N1	134.3 (3)
O1—C1—N2	126.0 (3)	C5—C6—C2	119.5 (3)
N1—C1—N2	106.8 (3)	N1—C6—C2	106.3 (3)
C1—N2—C2	109.5 (3)	N2—C7—C8	112.6 (3)
C1—N2—C7	124.0 (3)	N2—C7—H7A	109.1
C2—N2—C7	126.4 (3)	C8—C7—H7A	109.1
N3—C2—N2	126.4 (3)	N2—C7—H7B	109.1
N3—C2—C6	126.3 (3)	C8—C7—H7B	109.1
N2—C2—C6	107.3 (3)	H7A—C7—H7B	107.8
C2—N3—C3	114.0 (3)	C9—C8—C7	124.4 (5)
N3—C3—C4	123.0 (3)	C9—C8—H8	117.8
N3—C3—H3	118.5	C7—C8—H8	117.8
C4—C3—H3	118.5	C8—C9—H9A	120.0
C3—C4—C5	122.2 (3)	C8—C9—H9B	120.0
C3—C4—Br1	118.6 (3)	H9A—C9—H9B	120.0
C5—C4—Br1	119.2 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1i	0.86	1.95	2.798 (4)	168

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1i	0.86	1.95	2.798 (4)	168

Symmetry code: (i) .