6-Bromo-1,3-di-2-propynyl-1H-imidazo[4,5-b]pyridin-2(3H)-one

Abstract

The room-temperature reaction of propargyl bromide and 6-bromo-1,3-dihydro­imidazo[4,5-b]pyridin-2-one in dimethyl­formamide yields the title compound, C₁₂H₈BrN₃O, which features nitro­gen-bound propynyl substituents. The imidazopyridine fused ring is almost planar (r.m.s. deviation = 0.011 Å); the propynyl chains point in opposite directions relative to the fused ring. One acetyl­enic H atom is hydrogen bonded to the carbonyl O atom of an inversion-related mol­ecule, forming a dimer; adjacent dimers are linked by a second acetyl­ene–pyridine C—H⋯N inter­action, forming a layer motif.

Related literature

For the crystal structures of other imidazo[4,5-b]pyridin-2-ones, see: Kourafalos et al. (2002 ▶); Meanwell et al. (1995 ▶).

Experimental

Crystal data

• C₁₂H₈BrN₃O

• M _r = 290.12

• Monoclinic,

• a = 9.0725 (3) Å

• b = 18.6212 (5) Å

• c = 7.0684 (2) Å

• β = 102.995 (1)°

• V = 1163.56 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 3.52 mm⁻¹

• T = 293 K

• 0.35 × 0.30 × 0.15 mm

Data collection

• Bruker X8 APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.372, T _max = 0.620

• 27315 measured reflections

• 3383 independent reflections

• 2810 reflections with I > 2σ(I)

• R _int = 0.032

Refinement

• R[F ² > 2σ(F ²)] = 0.029

• wR(F ²) = 0.085

• S = 1.03

• 3383 reflections

• 162 parameters

• 2 restraints

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.87 e Å⁻³

• Δρ_min = −0.80 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: 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 ▶).

Supplementary Material

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C8—H8⋯O1i	0.95 (1)	2.53 (2)	3.392 (3)	151 (3)
C12—H12⋯N1ii	0.94 (1)	2.51 (2)	3.346 (2)	149 (2)

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Experimental

To a solution of 6-bromo-1,3-dihydroimidazo[4,5-b]pyridin-2-one (1 mmol), potassium carbonate (4 mmol) and tetra-n-butylammonium bromide (0.1 mmol) in DMF (20 ml) was added propargyl bromide (2.5 mmol). The solution was stirred for 48 hours. After completion of the reaction (as monitored byTLC), the salt was filtered and the solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel by using an ethyl acetate/hexane (1/1) mixture as eluent. Slow evaporation of the solvent furnished yellow crystals.

Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.93 to 0.97 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U(C). The terminal acetylenic H-atoms were located in a difference Fourier map, and were refined with a distance restraint of C–H 0.95±0.01 Å; their temperature factors were refined.

Figures

Fig. 1.

Thermal ellipsoid plot (Barbour, 2001) of C12H8BrN3O at the 50% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.

Crystal data

C12H8BrN3O	F(000) = 576
Mr = 290.12	Dx = 1.656 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9924 reflections
a = 9.0725 (3) Å	θ = 2.3–31.8°
b = 18.6212 (5) Å	µ = 3.52 mm−1
c = 7.0684 (2) Å	T = 293 K
β = 102.995 (1)°	Prism, yellow
V = 1163.56 (6) Å3	0.35 × 0.30 × 0.15 mm
Z = 4

Data collection

Bruker X8 APEXII diffractometer	3383 independent reflections
Radiation source: fine-focus sealed tube	2810 reflections with I > 2σ(I)
graphite	Rint = 0.032
φ and ω scans	θmax = 30.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.372, Tmax = 0.620	k = −26→26
27315 measured reflections	l = −9→9

Refinement

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.085	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ2(Fo2) + (0.0475P)2 + 0.4099P] where P = (Fo2 + 2Fc2)/3
3383 reflections	(Δ/σ)max = 0.001
162 parameters	Δρmax = 0.87 e Å−3
2 restraints	Δρmin = −0.80 e Å−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.40313 (3)	0.071904 (9)	0.35455 (3)	0.05174 (9)
O1	0.32318 (15)	0.47483 (7)	0.3528 (2)	0.0435 (3)
N1	0.12161 (15)	0.24467 (8)	0.3731 (2)	0.0354 (3)
N2	0.18505 (15)	0.37028 (8)	0.3651 (2)	0.0326 (3)
N3	0.42693 (14)	0.35966 (7)	0.35770 (18)	0.0289 (3)
C1	0.1822 (2)	0.17839 (9)	0.3720 (2)	0.0368 (4)
H1	0.1213	0.1387	0.3786	0.044*
C2	0.3302 (2)	0.16693 (8)	0.3614 (2)	0.0322 (3)
C3	0.43018 (17)	0.22350 (8)	0.3550 (2)	0.0289 (3)
H3	0.5302	0.2161	0.3481	0.035*
C4	0.21635 (17)	0.29782 (8)	0.3662 (2)	0.0279 (3)
C5	0.36927 (16)	0.29091 (8)	0.3596 (2)	0.0251 (3)
C6	0.0418 (2)	0.40256 (12)	0.3799 (3)	0.0457 (4)
H6A	0.0621	0.4471	0.4522	0.055*
H6B	−0.0093	0.3705	0.4524	0.055*
C7	−0.0586 (2)	0.41743 (12)	0.1911 (3)	0.0484 (5)
C8	−0.1389 (3)	0.43130 (16)	0.0410 (4)	0.0699 (8)
H8	−0.212 (3)	0.442 (2)	−0.073 (3)	0.108 (13)*
C9	0.31325 (18)	0.40998 (9)	0.3577 (2)	0.0307 (3)
C10	0.58352 (18)	0.38016 (10)	0.3664 (3)	0.0380 (4)
H10A	0.5957	0.4311	0.3946	0.046*
H10B	0.6068	0.3718	0.2408	0.046*
C11	0.68988 (18)	0.33965 (10)	0.5150 (3)	0.0397 (4)
C12	0.7772 (2)	0.30575 (14)	0.6294 (4)	0.0559 (6)
H12	0.849 (2)	0.2804 (13)	0.721 (3)	0.070 (8)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br1	0.07831 (18)	0.02651 (10)	0.04492 (13)	0.00475 (8)	0.00231 (10)	−0.00343 (6)
O1	0.0484 (7)	0.0281 (6)	0.0488 (7)	0.0041 (5)	−0.0001 (6)	0.0039 (5)
N1	0.0277 (6)	0.0436 (8)	0.0344 (7)	−0.0079 (6)	0.0059 (5)	−0.0006 (6)
N2	0.0261 (6)	0.0344 (7)	0.0357 (7)	0.0063 (5)	0.0039 (5)	0.0004 (5)
N3	0.0234 (6)	0.0261 (6)	0.0353 (6)	−0.0012 (4)	0.0023 (5)	0.0030 (5)
C1	0.0402 (9)	0.0356 (8)	0.0330 (8)	−0.0124 (7)	0.0050 (7)	−0.0002 (6)
C2	0.0437 (9)	0.0262 (7)	0.0246 (7)	−0.0018 (6)	0.0036 (6)	−0.0010 (5)
C3	0.0291 (7)	0.0294 (7)	0.0276 (7)	0.0028 (5)	0.0051 (6)	0.0003 (5)
C4	0.0248 (7)	0.0332 (7)	0.0240 (6)	0.0005 (5)	0.0022 (5)	−0.0001 (5)
C5	0.0237 (6)	0.0269 (7)	0.0236 (6)	−0.0015 (5)	0.0034 (5)	0.0005 (5)
C6	0.0346 (9)	0.0554 (11)	0.0481 (10)	0.0163 (8)	0.0114 (8)	−0.0029 (9)
C7	0.0306 (9)	0.0535 (11)	0.0610 (12)	0.0143 (8)	0.0101 (8)	0.0079 (9)
C8	0.0452 (13)	0.093 (2)	0.0672 (16)	0.0256 (12)	0.0040 (11)	0.0159 (13)
C9	0.0304 (7)	0.0294 (7)	0.0286 (7)	0.0028 (6)	−0.0014 (6)	0.0018 (6)
C10	0.0274 (7)	0.0392 (9)	0.0457 (9)	−0.0064 (6)	0.0047 (7)	0.0103 (7)
C11	0.0236 (7)	0.0455 (9)	0.0482 (10)	−0.0043 (6)	0.0042 (7)	0.0049 (8)
C12	0.0307 (9)	0.0659 (14)	0.0661 (14)	0.0016 (9)	0.0002 (9)	0.0171 (11)

Geometric parameters (Å, °)

Br1—C2	1.8935 (16)	C3—C5	1.375 (2)
O1—C9	1.212 (2)	C3—H3	0.9300
N1—C4	1.319 (2)	C4—C5	1.405 (2)
N1—C1	1.352 (2)	C6—C7	1.463 (3)
N2—C4	1.378 (2)	C6—H6A	0.9700
N2—C9	1.389 (2)	C6—H6B	0.9700
N2—C6	1.457 (2)	C7—C8	1.173 (3)
N3—C5	1.3842 (19)	C8—H8	0.948 (10)
N3—C9	1.394 (2)	C10—C11	1.466 (2)
N3—C10	1.459 (2)	C10—H10A	0.9700
C1—C2	1.379 (3)	C10—H10B	0.9700
C1—H1	0.9300	C11—C12	1.179 (3)
C2—C3	1.397 (2)	C12—H12	0.939 (10)
C4—N1—C1	114.56 (14)	N3—C5—C4	107.09 (13)
C4—N2—C9	110.37 (13)	N2—C6—C7	113.27 (16)
C4—N2—C6	126.11 (16)	N2—C6—H6A	108.9
C9—N2—C6	123.44 (15)	C7—C6—H6A	108.9
C5—N3—C9	109.91 (13)	N2—C6—H6B	108.9
C5—N3—C10	127.46 (14)	C7—C6—H6B	108.9
C9—N3—C10	122.53 (14)	H6A—C6—H6B	107.7
N1—C1—C2	122.96 (15)	C8—C7—C6	178.2 (3)
N1—C1—H1	118.5	C7—C8—H8	174 (2)
C2—C1—H1	118.5	O1—C9—N2	126.84 (15)
C1—C2—C3	122.16 (15)	O1—C9—N3	127.61 (16)
C1—C2—Br1	119.74 (12)	N2—C9—N3	105.55 (13)
C3—C2—Br1	118.10 (13)	N3—C10—C11	111.93 (14)
C5—C3—C2	114.86 (14)	N3—C10—H10A	109.2
C5—C3—H3	122.6	C11—C10—H10A	109.2
C2—C3—H3	122.6	N3—C10—H10B	109.2
N1—C4—N2	126.85 (15)	C11—C10—H10B	109.2
N1—C4—C5	126.10 (15)	H10A—C10—H10B	107.9
N2—C4—C5	107.05 (13)	C12—C11—C10	177.6 (2)
C3—C5—N3	133.58 (14)	C11—C12—H12	177.7 (17)
C3—C5—C4	119.33 (14)
C4—N1—C1—C2	−1.0 (2)	N1—C4—C5—C3	1.7 (2)
N1—C1—C2—C3	1.4 (3)	N2—C4—C5—C3	−178.61 (13)
N1—C1—C2—Br1	−178.53 (12)	N1—C4—C5—N3	−178.81 (14)
C1—C2—C3—C5	−0.2 (2)	N2—C4—C5—N3	0.92 (16)
Br1—C2—C3—C5	179.73 (10)	C4—N2—C6—C7	−93.3 (2)
C1—N1—C4—N2	179.82 (15)	C9—N2—C6—C7	90.2 (2)
C1—N1—C4—C5	−0.5 (2)	C4—N2—C9—O1	179.15 (16)
C9—N2—C4—N1	179.78 (15)	C6—N2—C9—O1	−3.9 (3)
C6—N2—C4—N1	2.9 (3)	C4—N2—C9—N3	−0.99 (17)
C9—N2—C4—C5	0.05 (17)	C6—N2—C9—N3	175.99 (15)
C6—N2—C4—C5	−176.84 (15)	C5—N3—C9—O1	−178.56 (16)
C2—C3—C5—N3	179.41 (15)	C10—N3—C9—O1	4.8 (3)
C2—C3—C5—C4	−1.2 (2)	C5—N3—C9—N2	1.58 (17)
C9—N3—C5—C3	177.86 (16)	C10—N3—C9—N2	−175.03 (14)
C10—N3—C5—C3	−5.7 (3)	C5—N3—C10—C11	−45.0 (2)
C9—N3—C5—C4	−1.58 (16)	C9—N3—C10—C11	131.00 (17)
C10—N3—C5—C4	174.83 (15)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8···O1i	0.95 (1)	2.53 (2)	3.392 (3)	151 (3)
C12—H12···N1ii	0.94 (1)	2.51 (2)	3.346 (2)	149 (2)

Symmetry codes: (i) −x, −y+1, −z; (ii) x+1, −y+1/2, z+1/2.