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

Abstract

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,

• a = 5.801 (1) Å

• b = 17.978 (5) Å

• c = 7.578 (2) Å

• β = 100.19 (4)°

• V = 777.8 (3) ų

• 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[F ² > 2σ(F ²)] = 0.049

• wR(F ²) = 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

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.

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
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) .

supplementary crystallographic information

Comment

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.

Experimental

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).

Refinement

The N-bound H atoms were located in a difference map and freely refined. The C-bound H atoms were positioned geometrically, with C—H = 0.93Å and refined as riding with U_iso(H) = 1.2U_eq(C).

Figures

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.

Crystal data

C6H4ClF3N2	F000 = 392
Mr = 196.56	Dx = 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 = 2.9–25.9º
c = 7.578 (2) Å	µ = 0.49 mm−1
β = 100.19 (4)º	T = 294 (2) K
V = 777.8 (3) Å3	Block, colourless
Z = 4	0.24 × 0.22 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer	1368 independent reflections
Radiation source: fine-focus sealed tube	904 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.054
T = 294(2) K	θmax = 25.0º
ω scans	θmin = 2.3º
Absorption correction: multi-scan(SADABS; Bruker, 1997)	h = −5→6
Tmin = 0.893, Tmax = 0.909	k = −21→20
3820 measured reflections	l = −9→5

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)] = 0.049	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.137	w = 1/[σ2(Fo2) + (0.0614P)2 + 0.3792P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max = 0.001
1368 reflections	Δρmax = 0.22 e Å−3
145 parameters	Δρmin = −0.18 e Å−3
39 restraints	Extinction correction: none
Primary atom site location: structure-invariant direct methods

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	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 (Ų)

	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, °)

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, °)

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 codes: (i) −x−1, −y+1, −z.