3-Chloro-5-meth­oxy-2,6-dinitro­pyridine

Abstract

In the crystal structure of the title compound, C₆H₄ClN₃O₅, the two nitro groups are twisted with respect to the pyridine ring, making dihedral angles of 33.12 (13) and 63.66 (14)°.

Related literature

For the synthesis, see: Bissell & Swansiger (1987 ▶); Chen et al. (2008 ▶).

Experimental

Crystal data

• C₆H₄ClN₃O₅

• M _r = 233.57

• Monoclinic,

• a = 6.6490 (13) Å

• b = 10.842 (2) Å

• c = 12.715 (3) Å

• β = 95.55 (3)°

• V = 912.3 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.43 mm⁻¹

• T = 293 K

• 0.50 × 0.40 × 0.28 mm

Data collection

• Rigaku R-AXIS RAPID IP diffractometer

• Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.808, T _max = 0.887

• 5866 measured reflections

• 2062 independent reflections

• 1275 reflections with I > 2σ(I)

• R _int = 0.050

Refinement

• R[F ² > 2σ(F ²)] = 0.048

• wR(F ²) = 0.135

• S = 0.99

• 2062 reflections

• 138 parameters

• H-atom parameters constrained

• Δρ_max = 0.26 e Å⁻³

• Δρ_min = −0.30 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

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

supplementary crystallographic information

Comment

Pyridine derivatives are important intermediates used to synthesize pesticide, medicine and play important roles in fine chemical field. 3-Chloro-5-methoxyl- 2,6-dinitro-pyridine was synthesized from 3,5-dichloropyridine N-oxide by substitution and nitration (Bissell et al., 1987), and the process was improved by Chen et al. (2008). The crystal structure of the title compound is presented here.

The molecular structure of the title compound is shown in Fig. 1. While the methoxyl group, except H atoms, is co-planar with the pyridine ring, the two nitro groups are twisted with respect to the pyridine ring with dihedral angles of 33.12 (13) and 63.66 (14)°, respectively. Neither hydrogen bonding nor π-π stacking is observed in the crystal structure.

Experimental

The title compound was prepared according to a literature method (Chen et al., 2008). Crystals suitable for X-ray analysis were obtained by slow evaporation of 1,2-dichloroethane.

Refinement

H atoms were positioned geometrically and refined using a ride model with C—H = 0.93 Å for aromatic H and 0.96 Å for methyl H atoms, U_iso(H) = 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) for aromatic H atom.

Figures

Fig. 1.

The molecular structure of title compound, with 30% probability displacement ellipsoids (arbitrary spheres for H atoms).

Crystal data

C6H4ClN3O5	F(000) = 472
Mr = 233.57	Dx = 1.701 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 5866 reflections
a = 6.6490 (13) Å	θ = 2.5–27.5°
b = 10.842 (2) Å	µ = 0.43 mm−1
c = 12.715 (3) Å	T = 293 K
β = 95.55 (3)°	Block, colorless
V = 912.3 (3) Å3	0.50 × 0.40 × 0.28 mm
Z = 4

Data collection

Rigaku R-AXIS RAPID IP diffractometer	2062 independent reflections
Radiation source: fine-focus sealed tube	1275 reflections with I > 2σ(I)
graphite	Rint = 0.050
Detector resolution: 10.00 pixels mm-1	θmax = 27.5°, θmin = 2.5°
ω scans	h = −8→8
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −13→13
Tmin = 0.808, Tmax = 0.887	l = −16→16
5866 measured reflections

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.048	H-atom parameters constrained
wR(F2) = 0.135	w = 1/[σ2(Fo2) + (0.08P)2] where P = (Fo2 + 2Fc2)/3
S = 0.99	(Δ/σ)max < 0.001
2062 reflections	Δρmax = 0.26 e Å−3
138 parameters	Δρmin = −0.30 e Å−3
0 restraints	Extinction correction: SHELXTL (Version 4.2; Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.157 (11)

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 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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.17055 (10)	0.52802 (8)	0.42365 (6)	0.0756 (3)
O1	0.8010 (3)	0.77739 (16)	0.37270 (12)	0.0536 (5)
O2	0.2241 (4)	0.3362 (2)	0.27062 (18)	0.0939 (8)
O3	0.2590 (3)	0.4071 (2)	0.11455 (16)	0.0716 (6)
O4	0.8115 (4)	0.7839 (2)	0.14363 (19)	0.0949 (8)
O5	0.9482 (4)	0.6061 (2)	0.1524 (2)	0.1051 (9)
N1	0.5510 (3)	0.55114 (17)	0.20338 (15)	0.0439 (5)
N2	0.2845 (3)	0.4126 (2)	0.2107 (2)	0.0590 (6)
N3	0.8230 (3)	0.6789 (2)	0.17477 (16)	0.0556 (6)
C1	0.4068 (3)	0.5141 (2)	0.25985 (18)	0.0440 (5)
C2	0.3749 (3)	0.5646 (2)	0.35677 (18)	0.0453 (6)
C3	0.5061 (3)	0.6544 (2)	0.39881 (17)	0.0443 (5)
H3	0.4898	0.6885	0.4645	0.053*
C4	0.6614 (3)	0.6929 (2)	0.34246 (16)	0.0407 (5)
C5	0.6705 (3)	0.6373 (2)	0.24397 (16)	0.0412 (5)
C6	0.7921 (5)	0.8349 (3)	0.47424 (19)	0.0657 (8)
H6A	0.6641	0.8754	0.4761	0.099*
H6B	0.8989	0.8944	0.4857	0.099*
H6C	0.8073	0.7732	0.5286	0.099*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0570 (4)	0.0974 (6)	0.0777 (5)	−0.0107 (4)	0.0343 (4)	0.0139 (4)
O1	0.0575 (10)	0.0580 (10)	0.0474 (9)	−0.0144 (8)	0.0153 (8)	−0.0112 (8)
O2	0.1109 (18)	0.0831 (15)	0.0882 (15)	−0.0542 (15)	0.0115 (13)	0.0088 (12)
O3	0.0704 (12)	0.0772 (13)	0.0661 (13)	−0.0183 (10)	0.0006 (10)	−0.0065 (10)
O4	0.1047 (18)	0.0908 (18)	0.0946 (16)	−0.0134 (14)	0.0377 (14)	0.0320 (13)
O5	0.0869 (16)	0.1075 (19)	0.133 (2)	0.0047 (15)	0.0717 (15)	−0.0076 (16)
N1	0.0418 (10)	0.0451 (10)	0.0457 (10)	−0.0002 (9)	0.0083 (8)	−0.0001 (8)
N2	0.0494 (12)	0.0609 (14)	0.0666 (15)	−0.0129 (11)	0.0060 (10)	0.0026 (11)
N3	0.0526 (12)	0.0688 (15)	0.0481 (11)	−0.0127 (11)	0.0182 (9)	−0.0061 (11)
C1	0.0400 (11)	0.0430 (12)	0.0492 (12)	−0.0024 (10)	0.0053 (10)	0.0060 (10)
C2	0.0388 (11)	0.0492 (13)	0.0493 (13)	0.0041 (10)	0.0121 (9)	0.0141 (10)
C3	0.0468 (12)	0.0476 (13)	0.0405 (12)	0.0064 (11)	0.0150 (9)	0.0035 (10)
C4	0.0415 (11)	0.0395 (11)	0.0422 (12)	0.0038 (10)	0.0096 (9)	0.0035 (9)
C5	0.0364 (10)	0.0460 (12)	0.0423 (11)	0.0004 (10)	0.0097 (9)	0.0037 (9)
C6	0.0845 (19)	0.0678 (17)	0.0463 (14)	−0.0182 (15)	0.0138 (13)	−0.0125 (12)

Geometric parameters (Å, °)

Cl1—C2	1.717 (2)	N3—C5	1.476 (3)
O1—C4	1.334 (3)	C1—C2	1.384 (3)
O1—C6	1.440 (3)	C2—C3	1.380 (3)
O2—N2	1.219 (3)	C3—C4	1.378 (3)
O3—N2	1.219 (3)	C3—H3	0.9300
O4—N3	1.206 (3)	C4—C5	1.396 (3)
O5—N3	1.201 (3)	C6—H6A	0.9600
N1—C5	1.300 (3)	C6—H6B	0.9600
N1—C1	1.315 (3)	C6—H6C	0.9600
N2—C1	1.472 (3)
C4—O1—C6	117.90 (18)	C4—C3—H3	120.3
C5—N1—C1	116.89 (19)	C2—C3—H3	120.3
O3—N2—O2	124.9 (2)	O1—C4—C3	126.4 (2)
O3—N2—C1	118.7 (2)	O1—C4—C5	117.78 (18)
O2—N2—C1	116.4 (2)	C3—C4—C5	115.8 (2)
O5—N3—O4	124.5 (2)	N1—C5—C4	126.05 (19)
O5—N3—C5	118.2 (2)	N1—C5—N3	114.31 (18)
O4—N3—C5	117.3 (2)	C4—C5—N3	119.6 (2)
N1—C1—C2	123.3 (2)	O1—C6—H6A	109.5
N1—C1—N2	113.5 (2)	O1—C6—H6B	109.5
C2—C1—N2	123.2 (2)	H6A—C6—H6B	109.5
C3—C2—C1	118.6 (2)	O1—C6—H6C	109.5
C3—C2—Cl1	118.16 (18)	H6A—C6—H6C	109.5
C1—C2—Cl1	123.13 (19)	H6B—C6—H6C	109.5
C4—C3—C2	119.3 (2)
C5—N1—C1—C2	1.9 (3)	C6—O1—C4—C5	−180.0 (2)
C5—N1—C1—N2	−177.3 (2)	C2—C3—C4—O1	−179.3 (2)
O3—N2—C1—N1	−31.5 (3)	C2—C3—C4—C5	1.0 (3)
O2—N2—C1—N1	145.0 (2)	C1—N1—C5—C4	0.9 (3)
O3—N2—C1—C2	149.3 (2)	C1—N1—C5—N3	−177.3 (2)
O2—N2—C1—C2	−34.2 (4)	O1—C4—C5—N1	178.0 (2)
N1—C1—C2—C3	−3.1 (3)	C3—C4—C5—N1	−2.3 (3)
N2—C1—C2—C3	176.0 (2)	O1—C4—C5—N3	−4.0 (3)
N1—C1—C2—Cl1	172.71 (17)	C3—C4—C5—N3	175.7 (2)
N2—C1—C2—Cl1	−8.2 (3)	O5—N3—C5—N1	−64.2 (3)
C1—C2—C3—C4	1.4 (3)	O4—N3—C5—N1	115.0 (3)
Cl1—C2—C3—C4	−174.58 (16)	O5—N3—C5—C4	117.5 (3)
C6—O1—C4—C3	0.3 (3)	O4—N3—C5—C4	−63.3 (3)