organic compounds
3-Chloro-2,4,5-trifluorobenzoic acid
aDepartment of Applied Chemistry, Nanjing College of Chemical Technology, Geguan Road No. 265 Nanjing, Nanjing 210048, People's Republic of China, and bChemical Engineering Department, Nanjing College of Chemical Technology, Geguan Road No. 265 Nanjing, Nanjing 210048, People's Republic of China
*Correspondence e-mail: njutshs@126.com
The title compound, C7H2ClF3O2, was prepared by the chlorination of 3-amino-2,4,5-trifluorobenzoic acid. The carboxyl group is twisted relative to the benzene ring by 6.8 (1)°. In the crystal, pairs of O—H⋯O hydrogen bonds link molecules into typical centrosymmetric carboxylic acid dimers. These dimers are arranged into sheets parallel to (-103).
Related literature
For applications of the title compound in synthesis, see: Sun et al. (2011). For a related structure, see: Zhu (2009).
Experimental
Crystal data
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Refinement
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Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); 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.
Supporting information
https://doi.org/10.1107/S1600536812049446/gk2539sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812049446/gk2539Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536812049446/gk2539Isup3.cml
A solid mixture of 0.52 g of 3-amino-2,4,5-trifluorobenzoic acid and 0.33 g of sodium nitrite was added in portions to a solution of 3 g of cupric chloride in 9 ml of water and 0.5 g of a 36% aqueous solution of hydrochloric acid. The resulting mixture was stirred for 1.5 h and then additional water (25 ml) and diethyl ether (20 ml) were added. The layers are separated and the aqueous layer extracted with diethyl ether. The combined organic extracts are extracted with 36% aqueous solution of hydrochloric acid and then concentrated on the rotary evaporator to give 0.45 g of 3-chloro-2,4,5-trifuorobenzoic acid as a light-brown solid. Crystals of the title compound suitable for X-ray analysis were obtained by slow evaporation of a toluene solution.
H atoms were positioned geometrically with O—H = 0.82 Å and C—H = 0.93 Å and constrained to ride on their parent atoms, with Uiso(H) =xUeq(C,O), where x = 1.5 for OH and x = 1.2 for CH H atoms.
Ethyl 8-chloro-1-cyclopropyl-6,7-difluoro-4-oxo-1,4-dihydroquinoline- 3-carboxylate is a key intermediate in the preparation of 7-aminosubstituted 8-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids which are useful as antibacterial agents and its
was recently reported (Sun et al., 2011). In turn 3-chloro-2,4,5-trifluorobenzoic acid, that is not commercially available, is an important material for its preparation. This compound is not easisly synthesized and herein we report its synthesis and the crystal structure.In the title molecule (Fig. 1) the carboxyl group forms a dihedral angle of 6.8 (1)° with the benzene ring. Intermolecular O—H···O hydrogen bond (Table 1) links the molecules into typical carboxylic acid dimers.
For applications of the title compound in synthesis, see: Sun et al. (2011). For a related structure, see: Zhu (2009).
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell
CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C7H2ClF3O2 | F(000) = 416 |
Mr = 210.54 | Dx = 1.860 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 25 reflections |
a = 4.4760 (9) Å | θ = 10–13° |
b = 13.654 (3) Å | µ = 0.52 mm−1 |
c = 12.400 (3) Å | T = 293 K |
β = 97.16 (3)° | Block, colourless |
V = 751.9 (3) Å3 | 0.30 × 0.20 × 0.10 mm |
Z = 4 |
Enraf–Nonius CAD-4 diffractometer | 699 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.092 |
Graphite monochromator | θmax = 25.4°, θmin = 2.2° |
ω/2θ scans | h = 0→5 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→16 |
Tmin = 0.859, Tmax = 0.950 | l = −14→14 |
1578 measured reflections | 3 standard reflections every 200 reflections |
1394 independent reflections | intensity decay: 1% |
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)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.132 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.052P)2] where P = (Fo2 + 2Fc2)/3 |
1394 reflections | (Δ/σ)max < 0.001 |
118 parameters | Δρmax = 0.16 e Å−3 |
0 restraints | Δρmin = −0.17 e Å−3 |
C7H2ClF3O2 | V = 751.9 (3) Å3 |
Mr = 210.54 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 4.4760 (9) Å | µ = 0.52 mm−1 |
b = 13.654 (3) Å | T = 293 K |
c = 12.400 (3) Å | 0.30 × 0.20 × 0.10 mm |
β = 97.16 (3)° |
Enraf–Nonius CAD-4 diffractometer | 699 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.092 |
Tmin = 0.859, Tmax = 0.950 | 3 standard reflections every 200 reflections |
1578 measured reflections | intensity decay: 1% |
1394 independent reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.132 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.16 e Å−3 |
1394 reflections | Δρmin = −0.17 e Å−3 |
118 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cl | 0.2118 (3) | 0.00527 (9) | 0.37810 (10) | 0.1012 (5) | |
F1 | 0.4799 (5) | 0.18021 (17) | 0.48010 (19) | 0.0847 (7) | |
C1 | 0.2598 (8) | 0.2017 (3) | 0.4004 (3) | 0.0618 (10) | |
O1 | 0.2232 (6) | 0.4641 (2) | 0.4113 (2) | 0.0892 (9) | |
O2 | 0.5635 (6) | 0.3685 (2) | 0.5008 (2) | 0.0849 (9) | |
H2A | 0.6253 | 0.4209 | 0.5272 | 0.127* | |
F2 | −0.2511 (6) | 0.0700 (2) | 0.2054 (2) | 0.1026 (9) | |
C2 | 0.1144 (10) | 0.1237 (3) | 0.3435 (3) | 0.0711 (11) | |
C3 | −0.1036 (10) | 0.1438 (4) | 0.2615 (3) | 0.0768 (12) | |
F3 | −0.4110 (5) | 0.2527 (2) | 0.15189 (18) | 0.0911 (8) | |
C4 | −0.1863 (9) | 0.2388 (3) | 0.2335 (3) | 0.0687 (11) | |
C5 | −0.0428 (8) | 0.3137 (3) | 0.2896 (3) | 0.0645 (10) | |
H5A | −0.0972 | 0.3778 | 0.2707 | 0.077* | |
C6 | 0.1844 (8) | 0.2971 (3) | 0.3749 (3) | 0.0555 (9) | |
C7 | 0.3271 (8) | 0.3836 (3) | 0.4317 (3) | 0.0583 (9) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl | 0.1469 (12) | 0.0629 (7) | 0.0972 (9) | 0.0035 (7) | 0.0284 (7) | −0.0006 (7) |
F1 | 0.1002 (18) | 0.0701 (15) | 0.0811 (14) | 0.0138 (13) | 0.0013 (13) | −0.0033 (13) |
C1 | 0.068 (3) | 0.067 (3) | 0.051 (2) | 0.006 (2) | 0.0116 (19) | 0.0000 (19) |
O1 | 0.103 (2) | 0.0606 (19) | 0.095 (2) | 0.0080 (16) | −0.0235 (17) | −0.0072 (16) |
O2 | 0.096 (2) | 0.0667 (18) | 0.086 (2) | 0.0034 (15) | −0.0111 (17) | −0.0161 (16) |
F2 | 0.122 (2) | 0.091 (2) | 0.0952 (18) | −0.0351 (16) | 0.0130 (15) | −0.0215 (16) |
C2 | 0.092 (3) | 0.061 (3) | 0.066 (3) | −0.005 (2) | 0.032 (2) | −0.004 (2) |
C3 | 0.080 (3) | 0.086 (3) | 0.067 (3) | −0.026 (3) | 0.020 (2) | −0.016 (3) |
F3 | 0.0777 (15) | 0.119 (2) | 0.0715 (14) | −0.0059 (14) | −0.0103 (13) | −0.0029 (15) |
C4 | 0.070 (3) | 0.079 (3) | 0.059 (2) | −0.011 (2) | 0.014 (2) | −0.007 (2) |
C5 | 0.068 (3) | 0.070 (3) | 0.057 (2) | −0.009 (2) | 0.0156 (19) | −0.004 (2) |
C6 | 0.056 (2) | 0.060 (2) | 0.053 (2) | −0.0027 (19) | 0.0150 (17) | −0.0031 (18) |
C7 | 0.069 (2) | 0.055 (2) | 0.050 (2) | 0.004 (2) | 0.0060 (18) | −0.0007 (17) |
Cl—C2 | 1.716 (4) | C2—C3 | 1.346 (6) |
F1—C1 | 1.338 (4) | C3—C4 | 1.381 (6) |
C1—C6 | 1.373 (5) | F3—C4 | 1.348 (4) |
C1—C2 | 1.393 (5) | C4—C5 | 1.354 (5) |
O1—C7 | 1.208 (4) | C5—C6 | 1.391 (5) |
O2—C7 | 1.293 (4) | C5—H5A | 0.9300 |
O2—H2A | 0.8200 | C6—C7 | 1.479 (5) |
F2—C3 | 1.349 (4) | ||
F1—C1—C6 | 121.0 (3) | F3—C4—C3 | 118.2 (4) |
F1—C1—C2 | 117.5 (4) | C5—C4—C3 | 119.1 (4) |
C6—C1—C2 | 121.5 (3) | C4—C5—C6 | 121.4 (4) |
C7—O2—H2A | 109.5 | C4—C5—H5A | 119.3 |
C3—C2—C1 | 118.4 (4) | C6—C5—H5A | 119.3 |
C3—C2—Cl | 121.2 (4) | C1—C6—C5 | 117.8 (3) |
C1—C2—Cl | 120.4 (3) | C1—C6—C7 | 124.7 (3) |
C2—C3—F2 | 120.0 (4) | C5—C6—C7 | 117.5 (3) |
C2—C3—C4 | 121.8 (4) | O1—C7—O2 | 123.0 (4) |
F2—C3—C4 | 118.2 (4) | O1—C7—C6 | 119.7 (3) |
F3—C4—C5 | 122.7 (4) | O2—C7—C6 | 117.2 (4) |
F1—C1—C2—C3 | −178.7 (3) | F3—C4—C5—C6 | 178.7 (3) |
C6—C1—C2—C3 | 0.3 (6) | C3—C4—C5—C6 | −0.3 (5) |
F1—C1—C2—Cl | 1.5 (5) | F1—C1—C6—C5 | 178.8 (3) |
C6—C1—C2—Cl | −179.5 (3) | C2—C1—C6—C5 | −0.2 (5) |
C1—C2—C3—F2 | −179.4 (3) | F1—C1—C6—C7 | −1.3 (5) |
Cl—C2—C3—F2 | 0.4 (6) | C2—C1—C6—C7 | 179.7 (3) |
C1—C2—C3—C4 | −0.5 (6) | C4—C5—C6—C1 | 0.2 (5) |
Cl—C2—C3—C4 | 179.3 (3) | C4—C5—C6—C7 | −179.7 (3) |
C2—C3—C4—F3 | −178.6 (3) | C1—C6—C7—O1 | −171.8 (4) |
F2—C3—C4—F3 | 0.3 (6) | C5—C6—C7—O1 | 8.1 (5) |
C2—C3—C4—C5 | 0.5 (6) | C1—C6—C7—O2 | 9.0 (5) |
F2—C3—C4—C5 | 179.4 (3) | C5—C6—C7—O2 | −171.1 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···O1i | 0.82 | 1.84 | 2.658 (4) | 178 |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C7H2ClF3O2 |
Mr | 210.54 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 4.4760 (9), 13.654 (3), 12.400 (3) |
β (°) | 97.16 (3) |
V (Å3) | 751.9 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.52 |
Crystal size (mm) | 0.30 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.859, 0.950 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1578, 1394, 699 |
Rint | 0.092 |
(sin θ/λ)max (Å−1) | 0.604 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.132, 1.00 |
No. of reflections | 1394 |
No. of parameters | 118 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.16, −0.17 |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···O1i | 0.8200 | 1.84 | 2.658 (4) | 178 |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Acknowledgements
The authors thank the Center of Testing and Analysis, Nanjing University, for support.
References
Enraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sun, H., Jiang, L., Li, Y.-L., Lu, X. & Xu, H. (2011). Acta Cryst. E67, o2974. CSD CrossRef IUCr Journals Google Scholar
Zhu, X. (2009). Acta Cryst. E65, o1886. Web of Science CSD CrossRef IUCr Journals Google Scholar
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Ethyl 8-chloro-1-cyclopropyl-6,7-difluoro-4-oxo-1,4-dihydroquinoline- 3-carboxylate is a key intermediate in the preparation of 7-aminosubstituted 8-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids which are useful as antibacterial agents and its crystal structure was recently reported (Sun et al., 2011). In turn 3-chloro-2,4,5-trifluorobenzoic acid, that is not commercially available, is an important material for its preparation. This compound is not easisly synthesized and herein we report its synthesis and the crystal structure.
In the title molecule (Fig. 1) the carboxyl group forms a dihedral angle of 6.8 (1)° with the benzene ring. Intermolecular O—H···O hydrogen bond (Table 1) links the molecules into typical carboxylic acid dimers.