2-Chloro-3-(2,2,2-trifluoro­ethoxy)pyridine

The title compound, C₇H₅ClF₃NO, was synthesized by the reaction of 2-chloro-3-hydroxy­pyridine with 2-chloro-1,1,1-trifluoro­ethane. The pyridine ring and the O and Cl atoms are nearly coplanar, the largest deviation from the mean plane being 0.078 (6) Å. Bioassay indicates that the title compound has a good fungicidal activity.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.079
• wR factor = 0.237
• Data-to-parameter ratio = 14.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         47 Perc.
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O1     -   C3      ..       6.85 su
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C1
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          9

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The organic fluorine derivatives have been investigated as pesticide (Sandford et al., 2004). This article focus on new pesticide containing trifluoroethoxy group.

The title compound, C₇H₅ClF₃NO, which is a derivative of 2-chloropyridine, was synthesized by the reaction of 2-Chloro-3-hydroxypyridine with 2-chloro-1,1,1-trifluoroethane, and characterized by ¹H NMR, IR, elemental analysis and single-crystal X-ray diffraction. The structure analysis reveals that the benzene ring, oxygen and chlorine atoms are neraly coplanar with the largest deviation from the mean plane being 0.078 (6) Å at C1(Fig. 1). Bioassay indicates that the title compound has a good fungicidal activity.

Related literature

For related literature, see: Sandford et al. (2004).

S2. Experimental

2-Chloro-3-hydroxypyridine (30 mmol) was dissolved in DMF (40 ml) and potassium carbonate (40 mmol) was added in one portion·A solution of 2-chloro-1,1,1-trifluoroethane (30 mmol) in DMF (20 ml) was then added to this mixture at 293 K. The resulting mixture was refluxed for 32 h. The mixture was filtered and the filtrate concentrated under reduced pressure to afford crude compound (I). Pure (I) was obtained by recrystallization from ethyl acetate. Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an ethanol solution. Spectroscopic analysis, ¹H NMR (CDCl₃, δ, p.p.m.): 8.54–8.55 (m, 1H), 7.82–7.84 (m, 1H), 7.65–7.67 (m, 1H),4.48 (m, 2H).

S3. Refinement

All H atoms were fixed geometrically and treated as riding with C—H = 0.93 Å (aromatic) or 0.97 Å (methylene) and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo,1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

Fig. 1. Molecular structure of (I) with the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radii.

2-Chloro-3-(2,2,2-trifluoroethoxy)pyridine

Crystal data

C7H5ClF3NO	F(000) = 848
Mr = 211.57	Dx = 1.574 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 25 reflections
a = 12.907 (3) Å	θ = 9–12°
b = 7.469 (2) Å	µ = 0.43 mm^−1
c = 18.520 (4) Å	T = 293 K
V = 1785.4 (7) Å^3	Block, colourless
Z = 8	0.40 × 0.30 × 0.30 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	814 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 26.0°, θmin = 2.2°
ω/2θ scans	h = 0→15
Absorption correction: ψ scan (North et al., 1968)	k = 0→9
Tmin = 0.846, Tmax = 0.881	l = 0→22
1749 measured reflections	3 standard reflections every 200 reflections
1749 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.080	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.237	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0827P)^2 + 3.9201P] where P = (Fo^2 + 2Fc^2)/3
1749 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.26 e Å^−3
0 restraints	Δρmin = −0.31 e Å^−3

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
C1	0.3876 (8)	0.2387 (13)	0.4626 (4)	0.089 (2)
C2	0.3770 (5)	0.2123 (10)	0.3840 (4)	0.078 (2)
H2A	0.4131	0.3065	0.3581	0.094*
H2B	0.4065	0.0980	0.3700	0.094*
C3	0.2438 (5)	0.1764 (7)	0.2976 (3)	0.0588 (15)
C4	0.1336 (4)	0.1758 (8)	0.2832 (3)	0.0561 (15)
C5	0.1602 (5)	0.1046 (11)	0.1698 (4)	0.081 (2)
H5	0.1328	0.0785	0.1245	0.097*
C6	0.2693 (5)	0.1007 (9)	0.1781 (3)	0.0692 (18)
H6	0.3129	0.0767	0.1393	0.083*
C7	0.3077 (4)	0.1340 (8)	0.2457 (3)	0.0562 (15)
H7	0.3785	0.1265	0.2546	0.067*
Cl1	0.04948 (12)	0.2192 (3)	0.35288 (11)	0.0830 (7)
F1	0.3504 (4)	0.3979 (8)	0.4816 (3)	0.1198 (17)
F2	0.4852 (4)	0.2529 (7)	0.4787 (2)	0.1119 (16)
F3	0.3469 (4)	0.1264 (8)	0.4989 (3)	0.1251 (19)
N1	0.0970 (4)	0.1421 (7)	0.2211 (3)	0.0710 (16)
O1	0.2678 (3)	0.2168 (6)	0.36733 (19)	0.0668 (12)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.101 (7)	0.091 (7)	0.074 (5)	0.009 (6)	−0.031 (5)	0.004 (5)
C2	0.049 (3)	0.083 (5)	0.102 (5)	0.015 (4)	−0.011 (3)	−0.015 (4)
C3	0.045 (3)	0.042 (3)	0.089 (4)	−0.003 (3)	−0.005 (4)	0.006 (3)
C4	0.041 (3)	0.060 (4)	0.067 (4)	0.004 (3)	−0.003 (3)	0.002 (3)
C5	0.067 (5)	0.109 (6)	0.067 (4)	−0.010 (4)	−0.012 (4)	−0.008 (4)
C6	0.063 (4)	0.075 (5)	0.070 (4)	−0.002 (4)	0.003 (3)	−0.012 (3)
C7	0.031 (3)	0.068 (4)	0.070 (4)	0.002 (3)	0.005 (3)	0.019 (3)
Cl1	0.0444 (8)	0.0978 (14)	0.1067 (14)	0.0030 (9)	0.0116 (9)	−0.0115 (11)
F1	0.128 (4)	0.118 (4)	0.114 (4)	0.006 (3)	−0.005 (3)	−0.004 (3)
F2	0.108 (4)	0.121 (4)	0.107 (4)	0.003 (3)	−0.016 (3)	−0.011 (3)
F3	0.145 (5)	0.122 (4)	0.108 (4)	−0.003 (4)	−0.013 (3)	0.005 (3)
N1	0.043 (3)	0.079 (4)	0.091 (4)	−0.001 (3)	−0.015 (3)	−0.020 (3)
O1	0.040 (2)	0.105 (4)	0.056 (2)	−0.001 (2)	−0.0037 (18)	−0.002 (2)

Geometric parameters (Å, º)

C1—F3	1.197 (9)	C3—C4	1.447 (8)
C1—F2	1.299 (10)	C4—N1	1.269 (7)
C1—F1	1.330 (9)	C4—Cl1	1.717 (6)
C1—C2	1.474 (10)	C5—N1	1.284 (8)
C2—O1	1.443 (7)	C5—C6	1.417 (9)
C2—H2A	0.9700	C5—H5	0.9300
C2—H2B	0.9700	C6—C7	1.370 (8)
C3—C7	1.305 (8)	C6—H6	0.9300
C3—O1	1.363 (7)	C7—H7	0.9300
F3—C1—F2	110.7 (7)	N1—C4—C3	122.2 (5)
F3—C1—F1	108.6 (8)	N1—C4—Cl1	118.9 (5)
F2—C1—F1	102.5 (8)	C3—C4—Cl1	118.9 (5)
F3—C1—C2	114.9 (8)	N1—C5—C6	123.8 (6)
F2—C1—C2	109.1 (8)	N1—C5—H5	118.1
F1—C1—C2	110.4 (7)	C6—C5—H5	118.1
O1—C2—C1	107.4 (6)	C7—C6—C5	117.1 (6)
O1—C2—H2A	110.2	C7—C6—H6	121.5
C1—C2—H2A	110.2	C5—C6—H6	121.5
O1—C2—H2B	110.2	C3—C7—C6	119.2 (6)
C1—C2—H2B	110.2	C3—C7—H7	120.4
H2A—C2—H2B	108.5	C6—C7—H7	120.4
C7—C3—O1	127.4 (5)	C4—N1—C5	118.6 (5)
C7—C3—C4	119.0 (6)	C3—O1—C2	114.9 (5)
O1—C3—C4	113.5 (5)