2-Bromo­pyridine-3-carboxylic acid

Abstract

The carboxylic acid residue in the title compound, C₆H₄BrNO₂, is twisted out of the plane of the other atoms, as indicated by the (Br)C—C—C—O_carbon­yl torsion angle of −20.1 (9)°. In the crystal, supra­molecular chains mediated by O—H⋯N hydrogen bonds are formed with base vector [201] and C—H⋯O inter­actions reinforce the packing.

Related literature

For the biological activity of N-heterocylic compounds, see: de Souza (2005 ▶); Cunico et al. (2006 ▶). For related structures, see: Wright & King (1953 ▶); Kutoglu & Scheringer (1983 ▶); de Souza et al. (2005 ▶); Kaiser et al. (2009 ▶). For the synthesis, see: Bradlow & van der Werf (1949 ▶).

Experimental

Crystal data

• C₆H₄BrNO₂

• M _r = 202.01

• Monoclinic,

• a = 3.9286 (3) Å

• b = 12.9737 (9) Å

• c = 12.8570 (8) Å

• β = 96.695 (4)°

• V = 650.83 (8) ų

• Z = 4

• Mo Kα radiation

• μ = 6.24 mm⁻¹

• T = 120 K

• 0.10 × 0.09 × 0.08 mm

Data collection

• Nonius KappaCCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2007 ▶) T _min = 0.453, T _max = 0.607

• 7699 measured reflections

• 1147 independent reflections

• 882 reflections with I > 2σ(I)

• R _int = 0.070

Refinement

• R[F ² > 2σ(F ²)] = 0.038

• wR(F ²) = 0.093

• S = 1.06

• 1147 reflections

• 92 parameters

• H-atom parameters constrained

• Δρ_max = 0.86 e Å⁻³

• Δρ_min = −0.62 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); 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
O1—H1⋯N1i	0.84	1.85	2.685 (5)	173
C5—H5⋯O2ii	0.95	2.39	3.258 (7)	152
C6—H6⋯O2iii	0.95	2.47	3.171 (6)	131

Symmetry codes: (i) ; (ii) ; (iii) .

supplementary crystallographic information

Comment

The structure of the title compound, (I), was determined in connection with on-going studies of biological activitiess, e.g. anti-mycobacterial activity, of N-heterocyclic compounds (Cunico et al. 2006; de Souza, 2005), as we have embarked on complementary systematic structural investigations in order to ascertain supramolecular aggregation patterns (Kaiser et al., 2009).

In the molecular structure of (I), Fig. 1, the carbonyl-O2 atom is approximately syn to the bromide. The carboxylic acid residue is twisted out of the plane of the pyridine ring as seen in the value of the C2/C3/C7/O1 torsion angle of 161.1 (5)°. In the crystal packing, a supramolecular chain with base vector [2 0 1] is formed through the agency of O–H···N hydrogen bonds, Fig. 2 and Table 1. Additional stabilisation to the chains are afforded by C–H···O_carbonyl interactions, Table 1. The chains stack into layers in the ab place and are consolidated in the crystal structure by further C–H···O_carbonyl contacts, Fig. 2 & Table 1. Similar supramolecular chains are found in the crystal structures of nicotinic acid (Wright & King, 1953; Kutoglu & Scheringer, 1983) as well as in 2-chloropyridine-3-carboxylic acid (de Souza et al., 2005).

Experimental

A mixture of 2-bromo-3-methylpyridine (0.77 g, 4.5 mmol), KMnO₄ (0.316 g, 2 mmol) and H₂O (20 ml) was refluxed until the purple colour of the solution disappeared. A second portion of KMnO₄ (0.316 g) and water (10 ml) were added and the reaction mixture was refluxed again until no purple colour remained. The reaction mixture was concentrated to 10 ml, acidified with concentrated hydrochloric acid, and filtered. The precipitate was washed with cold water and cold diethylether (20 ml). The yield was 0.79 g (60%), m.p. 520–523 K; lit value 522-523 K (Bradlow & van der Werf, 1949). 2-Bromonicotinic acid was recrystallised from EtOH for the crystallographic study. ¹H NMR [500.00 MHz, DMSO-d₆] δ: 8.50 (1H, dd, J = 5.0 and 2.0 Hz, H6), 8.13 (1H, dd, J = 7.5 and 2.0 Hz, H4), 7.55 (1H, dd, J = 7.5 and 5.0 Hz, H5), 3.44 (1H, s, OH) p.p.m. ¹³C NMR (125.0 MHz, DMSO-d₆) δ: 166.3, 151.8, 139.1, 138.6, 131.1, 123.2 p.p.m.

Refinement

The C-bound H atoms were geometrically placed (C–H = 0.95 Å) and refined as riding with U_iso(H) = 1.2U_eq(C). The N-bound H atoms were located from a difference map and refined with U_iso(H) = 1.5U_eq(N).

Figures

Fig. 1.

The molecular structure of (I) showing displacement ellipsoids at the 50% probability level.

Fig. 2.

View of the unit cell contents in (I) highlighting the N–H···O hydrogen bonding (orange dashed lines) leading to supramolecular chains, and C–H···O contacts within and between chains (blue dashed lines). Colour code: Br, olive; O, red; N, blue; C, grey; and H, green.

Crystal data

C6H4BrNO2	F(000) = 392
Mr = 202.01	Dx = 2.062 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 24006 reflections
a = 3.9286 (3) Å	θ = 2.9–27.5°
b = 12.9737 (9) Å	µ = 6.24 mm−1
c = 12.8570 (8) Å	T = 120 K
β = 96.695 (4)°	Block, colourless
V = 650.83 (8) Å3	0.10 × 0.09 × 0.08 mm
Z = 4

Data collection

Nonius KappaCCD area-detector diffractometer	1147 independent reflections
Radiation source: Enraf Nonius FR591 rotating anode	882 reflections with I > 2σ(I)
10 cm confocal mirrors	Rint = 0.070
Detector resolution: 9.091 pixels mm-1	θmax = 25.0°, θmin = 3.2°
φ and ω scans	h = −4→4
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −15→15
Tmin = 0.453, Tmax = 0.607	l = −15→13
7699 measured reflections

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.093	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0439P)2 + 1.1585P] where P = (Fo2 + 2Fc2)/3
1147 reflections	(Δ/σ)max = 0.001
92 parameters	Δρmax = 0.86 e Å−3
0 restraints	Δρmin = −0.62 e Å−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Ų)

	x	y	z	Uiso*/Ueq
Br	0.26644 (13)	0.59770 (4)	0.89357 (4)	0.0284 (2)
O1	−0.1485 (10)	0.8088 (3)	0.6204 (3)	0.0329 (9)
H1	−0.2563	0.7783	0.5691	0.049*
O2	0.0225 (11)	0.6488 (3)	0.6647 (3)	0.0484 (12)
N1	0.5499 (10)	0.7843 (3)	0.9471 (3)	0.0257 (10)
C2	0.3563 (13)	0.7384 (4)	0.8676 (4)	0.0237 (11)
C3	0.2287 (12)	0.7899 (4)	0.7756 (4)	0.0246 (11)
C4	0.3069 (14)	0.8942 (4)	0.7698 (4)	0.0303 (12)
H4	0.2193	0.9327	0.7098	0.036*
C5	0.5111 (13)	0.9428 (4)	0.8507 (4)	0.0252 (12)
H5	0.5688	1.0137	0.8461	0.030*
C6	0.6276 (13)	0.8854 (4)	0.9378 (4)	0.0268 (12)
H6	0.7679	0.9179	0.9935	0.032*
C7	0.0240 (13)	0.7406 (4)	0.6822 (4)	0.0290 (12)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br	0.0342 (3)	0.0217 (3)	0.0277 (3)	−0.0033 (2)	−0.0029 (2)	0.0016 (2)
O1	0.042 (2)	0.030 (2)	0.025 (2)	0.0023 (18)	−0.0059 (17)	−0.0007 (16)
O2	0.072 (3)	0.027 (2)	0.041 (2)	0.009 (2)	−0.018 (2)	−0.0066 (19)
N1	0.031 (2)	0.024 (2)	0.023 (2)	0.0023 (19)	0.0034 (19)	−0.0008 (19)
C2	0.021 (2)	0.024 (3)	0.026 (3)	0.002 (2)	0.005 (2)	−0.001 (2)
C3	0.023 (3)	0.026 (3)	0.024 (3)	0.005 (2)	0.002 (2)	−0.003 (2)
C4	0.035 (3)	0.025 (3)	0.029 (3)	0.003 (2)	−0.003 (2)	0.003 (2)
C5	0.030 (3)	0.020 (3)	0.026 (3)	−0.001 (2)	0.003 (2)	−0.003 (2)
C6	0.027 (3)	0.028 (3)	0.024 (3)	0.000 (2)	−0.002 (2)	−0.007 (2)
C7	0.028 (3)	0.031 (3)	0.027 (3)	0.003 (2)	0.000 (2)	0.002 (2)

Geometric parameters (Å, °)

Br—C2	1.897 (5)	C3—C4	1.392 (7)
O1—C7	1.322 (6)	C3—C7	1.507 (7)
O1—H1	0.8400	C4—C5	1.388 (7)
O2—C7	1.213 (6)	C4—H4	0.9500
N1—C2	1.340 (6)	C5—C6	1.378 (7)
N1—C6	1.356 (6)	C5—H5	0.9500
C2—C3	1.400 (7)	C6—H6	0.9500
C7—O1—H1	109.5	C3—C4—H4	119.5
C2—N1—C6	118.4 (4)	C6—C5—C4	118.1 (5)
N1—C2—C3	123.3 (5)	C6—C5—H5	121.0
N1—C2—Br	113.2 (3)	C4—C5—H5	121.0
C3—C2—Br	123.5 (4)	N1—C6—C5	122.6 (4)
C4—C3—C2	116.7 (5)	N1—C6—H6	118.7
C4—C3—C7	118.1 (4)	C5—C6—H6	118.7
C2—C3—C7	125.2 (4)	O2—C7—O1	123.7 (5)
C5—C4—C3	120.9 (5)	O2—C7—C3	123.8 (5)
C5—C4—H4	119.5	O1—C7—C3	112.6 (4)
C2—C3—C7—O1	161.1 (5)	C2—C3—C7—O2	−20.1 (9)
C4—C3—C7—O1	−20.7 (7)	C4—C3—C7—O2	158.1 (6)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1i	0.84	1.85	2.685 (5)	173
C5—H5···O2ii	0.95	2.39	3.258 (7)	152
C6—H6···O2iii	0.95	2.47	3.171 (6)	131

Symmetry codes: (i) x−1, −y+3/2, z−1/2; (ii) −x+1, y+1/2, −z+3/2; (iii) x+1, −y+3/2, z+1/2.