3-Chloro-5-(trifluoro­meth­yl)pyridin-2-amine

Tan, S.; Feng, G.-B.; Chen, X.-J.; Shang, Z.-H.

doi:10.1107/S1600536807060205

organic compounds

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ISSN: 2056-9890

Volume 64| Part 2| February 2008| Page o430

doi:10.1107/S1600536807060205

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3-Chloro-5-(trifluoromethyl)pyridin-2-amine

Sheng Tan,^a ^* Guang-Bin Feng,^a Xue-Jun Chen ^a and Zhen-Hua Shang ^b

^aOrdnance Technology Institute, Ordnance Engineering College, Shijiazhuang 050003, People's Republic of China, and ^bCollege of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, People's Republic of China
^*Correspondence e-mail: shengtan2007@yahoo.com.cn

(Received 29 October 2007; accepted 17 November 2007; online 11 January 2008)

In the title compound, C₆H₄ClF₃N₂, an intermediate in the synthesis of the fungicide fluazinam, the F atoms of the trifluoromethyl group are disordered over two sites in a 0.683 (14):0.317 (14) ratio. In the crystal structure, centrosymmetric dimers arise from pairs of N—H⋯N hydrogen bonds.

Related literature

For related literature, see: Guo et al. (1991 ).

Experimental

Crystal data

C₆H₄ClF₃N₂
M_r = 196.56
Monoclinic, P 2₁ /n
a = 5.801 (1) Å
b = 17.978 (5) Å
c = 7.578 (2) Å
β = 100.19 (4)°
V = 777.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.49 mm⁻¹
T = 294 (2) K
0.24 × 0.22 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1997 ) T_min = 0.893, T_max = 0.909
3820 measured reflections
1368 independent reflections
904 reflections with I > 2σ(I)
R_int = 0.054

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.137
S = 1.01
1368 reflections
145 parameters
39 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯Cl1	0.89 (2)	2.60 (3)	2.965 (9)	105.3 (19)
N2—H2B⋯N1ⁱ	0.89 (3)	2.16 (3)	3.049 (9)	171 (3)
Symmetry code: (i) -x-1, -y+1, -z.

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807060205/hb2620sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536807060205/hb2620Isup2.hkl

checkCIF report

Comment top

The title compound, (I), is an intermediate in the preparation of fluazinam or 3-chloro-N-[3-chloro-2,6-dinitro- 4-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2-pyridinamine which is a kind of pyridine fungicide (Guo et al., 1991).

The F atoms of the trifluoromethyl group are disordered over two sites in a 0.683 (14):0.317 (14) ratio (Fig. 1). An acute intramolecular N—H···Cl interaction occurs and the packing is consolidated by an N—H···N hydrogen bond (Table 1) resulting in inversion dimers.

Related literature top

For related literature, see: Guo et al. (1991).

Experimental top

A mixture of 2,3-dichloro-5-(trifluoromethyl)pyridine (216 g, 1 mol) and NH~3 (68 g, 4 mol) in ethanol was heated to 50 atm. After 10 h, the reaction was complete, the resulting solid was filtered off and washed with a little cool ethanol. 50 mg of (I) was dissolved in 20 ml e thanol and the solution was kept at room temperature for 10 d; natural evaporation gave colourless blocks of (I).

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.

Figures top

	Fig. 1. The molecular structure of (I), drawn with 30% probability ellipsoids (arbitrary spheres for the H atoms). Only one orientation of the –CF₃ group is shown. The N—H···Cl interaction is shown as a double-dashed line.
	Fig. 2. The formation of the title compound.

3-Chloro-5-(trifluoromethyl)pyridin-2-amine top

Crystal data top

C₆H₄ClF₃N₂	F(000) = 392
M_r = 196.56	D_x = 1.678 Mg m⁻³
Monoclinic, P2₁/n	Melting point = 145–146 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 5.801 (1) Å	Cell parameters from 1210 reflections
b = 17.978 (5) Å	θ = 2.9–25.9°
c = 7.578 (2) Å	µ = 0.49 mm⁻¹
β = 100.19 (4)°	T = 294 K
V = 777.8 (3) Å³	Block, colourless
Z = 4	0.24 × 0.22 × 0.20 mm

Data collection top

Bruker SMART CCD diffractometer	1368 independent reflections
Radiation source: fine-focus sealed tube	904 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.054
ω scans	θ_max = 25.0°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −5→6
T_min = 0.893, T_max = 0.909	k = −21→20
3820 measured reflections	l = −9→5

Refinement top

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)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ²(F_o²) + (0.0614P)² + 0.3792P] where P = (F_o² + 2F_c²)/3
1368 reflections	(Δ/σ)_max = 0.001
145 parameters	Δρ_max = 0.22 e Å⁻³
39 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₆H₄ClF₃N₂	V = 777.8 (3) Å³
M_r = 196.56	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 5.801 (1) Å	µ = 0.49 mm⁻¹
b = 17.978 (5) Å	T = 294 K
c = 7.578 (2) Å	0.24 × 0.22 × 0.20 mm
β = 100.19 (4)°

Data collection top

Bruker SMART CCD diffractometer	1368 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1997)	904 reflections with I > 2σ(I)
T_min = 0.893, T_max = 0.909	R_int = 0.054
3820 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	39 restraints
wR(F²) = 0.137	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	Δρ_max = 0.22 e Å⁻³
1368 reflections	Δρ_min = −0.18 e Å⁻³
145 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Cl1	0.19339 (18)	0.59163 (5)	0.35440 (14)	0.0682 (4)
F1	0.075 (2)	0.2514 (7)	0.3252 (15)	0.117 (4)	0.683 (14)
F2	0.2861 (13)	0.2807 (3)	0.1285 (11)	0.108 (2)	0.683 (14)
F3	0.4036 (17)	0.3071 (3)	0.3974 (16)	0.131 (4)	0.683 (14)
F1'	0.078 (4)	0.2487 (13)	0.256 (3)	0.097 (6)	0.317 (14)
F2'	0.392 (4)	0.2973 (9)	0.246 (4)	0.127 (6)	0.317 (14)
F3'	0.267 (3)	0.3002 (6)	0.4870 (18)	0.107 (5)	0.317 (14)
N1	−0.2580 (5)	0.44234 (16)	0.1206 (4)	0.0537 (8)
N2	−0.2851 (6)	0.56838 (18)	0.1481 (5)	0.0658 (9)
C1	−0.1364 (6)	0.3800 (2)	0.1569 (5)	0.0548 (9)
H1	−0.2072	0.3355	0.1145	0.066*
C2	0.0859 (6)	0.3770 (2)	0.2526 (5)	0.0540 (9)
C3	0.1917 (6)	0.4434 (2)	0.3143 (5)	0.0540 (9)
H3	0.3441	0.4439	0.3781	0.065*
C4	0.0705 (6)	0.50724 (19)	0.2804 (4)	0.0460 (8)
C5	−0.1582 (6)	0.50666 (18)	0.1823 (4)	0.0468 (9)
C6	0.2091 (10)	0.3053 (3)	0.2854 (8)	0.0837 (15)
H2A	−0.230 (5)	0.6135 (10)	0.181 (5)	0.070 (13)*
H2B	−0.426 (4)	0.5678 (18)	0.078 (4)	0.076 (13)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0704 (7)	0.0546 (6)	0.0765 (7)	−0.0139 (5)	0.0049 (5)	−0.0129 (5)
F1	0.143 (5)	0.074 (5)	0.141 (7)	0.016 (4)	0.037 (6)	0.046 (5)
F2	0.132 (4)	0.077 (3)	0.116 (5)	0.042 (3)	0.027 (4)	−0.011 (3)
F3	0.120 (5)	0.092 (3)	0.150 (6)	0.039 (3)	−0.065 (5)	−0.017 (4)
F1'	0.110 (9)	0.053 (7)	0.115 (10)	0.006 (6)	−0.014 (8)	−0.012 (8)
F2'	0.114 (9)	0.123 (8)	0.153 (11)	0.054 (7)	0.052 (9)	0.024 (8)
F3'	0.135 (9)	0.077 (6)	0.097 (7)	0.039 (6)	−0.009 (7)	0.020 (5)
N1	0.0483 (17)	0.0481 (17)	0.0600 (19)	−0.0008 (14)	−0.0036 (14)	−0.0038 (14)
N2	0.060 (2)	0.0489 (19)	0.082 (2)	0.0067 (17)	−0.0063 (18)	−0.0031 (17)
C1	0.058 (2)	0.046 (2)	0.059 (2)	−0.0055 (18)	0.0029 (18)	−0.0059 (16)
C2	0.055 (2)	0.049 (2)	0.055 (2)	0.0041 (18)	0.0020 (18)	0.0006 (16)
C3	0.046 (2)	0.059 (2)	0.054 (2)	0.0014 (18)	−0.0015 (16)	−0.0009 (17)
C4	0.048 (2)	0.048 (2)	0.0419 (19)	−0.0069 (16)	0.0080 (16)	−0.0039 (15)
C5	0.052 (2)	0.0460 (19)	0.0430 (19)	0.0037 (17)	0.0091 (16)	0.0007 (15)
C6	0.076 (4)	0.060 (3)	0.105 (4)	0.000 (3)	−0.012 (3)	0.002 (3)

Geometric parameters (Å, º) top

Cl1—C4	1.727 (5)	N2—H2A	0.891 (11)
F1—C6	1.311 (13)	N2—H2B	0.895 (11)
F2—C6	1.414 (9)	C1—C2	1.364 (6)
F3—C6	1.287 (7)	C1—H1	0.9300
F1'—C6	1.27 (2)	C2—C3	1.385 (6)
F2'—C6	1.162 (14)	C2—C6	1.474 (6)
F3'—C6	1.508 (15)	C3—C4	1.347 (5)
N1—C1	1.327 (5)	C3—H3	0.9300
N1—C5	1.340 (5)	C4—C5	1.401 (6)
N2—C5	1.332 (5)

C1—N1—C5	118.4 (3)	F2'—C6—F3	55.6 (11)
C5—N2—H2A	123 (2)	F1'—C6—F3	124.4 (11)
C5—N2—H2B	121 (2)	F2'—C6—F1	125.0 (11)
H2A—N2—H2B	115.1 (19)	F1'—C6—F1	23.6 (11)
N1—C1—C2	124.1 (3)	F3—C6—F1	110.7 (8)
N1—C1—H1	117.9	F2'—C6—F2	46.1 (14)
C2—C1—H1	117.9	F1'—C6—F2	82.5 (11)
C1—C2—C3	117.8 (3)	F3—C6—F2	101.0 (7)
C1—C2—C6	120.6 (4)	F1—C6—F2	104.5 (7)
C3—C2—C6	121.6 (4)	F2'—C6—C2	120.2 (8)
C4—C3—C2	119.0 (4)	F1'—C6—C2	114.6 (12)
C4—C3—H3	120.5	F3—C6—C2	115.6 (5)
C2—C3—H3	120.5	F1—C6—C2	113.4 (8)
C3—C4—C5	120.5 (3)	F2—C6—C2	110.4 (5)
C3—C4—Cl1	121.0 (3)	F2'—C6—F3'	101.6 (12)
C5—C4—Cl1	118.4 (3)	F1'—C6—F3'	98.5 (10)
N2—C5—N1	117.5 (3)	F3—C6—F3'	47.3 (6)
N2—C5—C4	122.4 (3)	F1—C6—F3'	75.9 (8)
N1—C5—C4	120.1 (3)	F2—C6—F3'	141.9 (7)
F2'—C6—F1'	113.8 (16)	C2—C6—F3'	103.8 (6)

C5—N1—C1—C2	−0.5 (5)	C1—C2—C6—F2'	125.8 (19)
N1—C1—C2—C3	−0.6 (6)	C3—C2—C6—F2'	−53 (2)
N1—C1—C2—C6	−179.5 (4)	C1—C2—C6—F1'	−15.4 (13)
C1—C2—C3—C4	1.2 (5)	C3—C2—C6—F1'	165.7 (12)
C6—C2—C3—C4	−179.9 (4)	C1—C2—C6—F3	−170.6 (9)
C2—C3—C4—C5	−0.8 (5)	C3—C2—C6—F3	10.5 (11)
C2—C3—C4—Cl1	179.9 (3)	C1—C2—C6—F1	−41.3 (9)
C1—N1—C5—N2	−178.4 (3)	C3—C2—C6—F1	139.8 (7)
C1—N1—C5—C4	0.9 (5)	C1—C2—C6—F2	75.5 (6)
C3—C4—C5—N2	179.0 (3)	C3—C2—C6—F2	−103.3 (6)
Cl1—C4—C5—N2	−1.6 (5)	C1—C2—C6—F3'	−121.6 (9)
C3—C4—C5—N1	−0.3 (5)	C3—C2—C6—F3'	59.5 (10)
Cl1—C4—C5—N1	179.1 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···Cl1	0.89 (2)	2.60 (3)	2.965 (9)	105 (2)
N2—H2B···N1ⁱ	0.89 (3)	2.16 (3)	3.049 (9)	171 (3)

Symmetry code: (i) −x−1, −y+1, −z.

Experimental details

Crystal data
Chemical formula	C₆H₄ClF₃N₂
M_r	196.56
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	294
a, b, c (Å)	5.801 (1), 17.978 (5), 7.578 (2)
β (°)	100.19 (4)
V (Å³)	777.8 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.49
Crystal size (mm)	0.24 × 0.22 × 0.20

Data collection
Diffractometer	Bruker SMART CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 1997)
T_min, T_max	0.893, 0.909
No. of measured, independent and observed [I > 2σ(I)] reflections	3820, 1368, 904
R_int	0.054
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.137, 1.02
No. of reflections	1368
No. of parameters	145
No. of restraints	39
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.22, −0.18

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997), SHELXTL.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···Cl1	0.89 (2)	2.60 (3)	2.965 (9)	105.3 (19)
N2—H2B···N1ⁱ	0.89 (3)	2.16 (3)	3.049 (9)	171 (3)

Symmetry code: (i) −x−1, −y+1, −z.

Acknowledgements

The authors thank the fund of the Ordnance Technology Institute for support.

References

Bruker (1997). SADABS (Version 2.0), SMART (Version 5.611), SAINT (Version 6.0) and SHELXTL (Version 5.10). Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Guo, Z.-J., Miyoshi, H., Komyoji, T., Haga, T. & Fujita, T. (1991). Biochim. Biophys. Acta, 1056, 89–92. CrossRef CAS Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar