Synthetic method for 3, 5-dichloro-2, 4-difluoronitrobenzene and teflubenzuron
A technology of difluoronitrobenzene and difluoroaniline, which is applied in the field of synthesis of 3,5-dichloro-2,4-difluoronitrobenzene and pyrifluran, can solve the problems of complex process and high cost, and achieve The synthesis process is simple, the reaction conditions are mild, and the raw materials are easily available
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0032] Dissolve 31.8g (0.2mol) of 2,4-difluoronitrobenzene and 2.0g iodine in 50mL of 98% concentrated sulfuric acid, raise the temperature to 160°C and start to pass chlorine gas, react for 8h, stop passing chlorine, and pour the reaction solution into ice In water, the organic phase was washed with NaOH aqueous solution until neutral to obtain 3,5-dichloro-2,4-difluoronitrobenzene. The infrared spectrogram and mass spectrum of above-mentioned 3,5-dichloro-2,4-difluoronitrobenzene are as follows respectively figure 1 and figure 2 shown.
[0033] IR (cm -1 ): 3096 (aromatic ring = C-H), 1543 (aromatic ring C = C), 1343 (NO 2 Nitrogen-oxygen bond), 1266(C-F), 1166(C-Cl).
[0034] 75mL of industrial ethanol, 50mL of water, 2.5mL of glacial acetic acid, 1.0g of ammonium chloride and 22.5g of reduced iron powder were refluxed for 0.5h under reflux, and 22.8 g (0.1mol), reflux for 5 hours, add sodium carbonate solution to adjust the pH = 9 to 10, steam distillation to distill...
Embodiment 2
[0037] The synthesis operation of 3,5-dichloro-2,4-difluoronitrobenzene is the same as in Example 1, the solvent is 80 mL dimethyl sulfoxide (DMSO), the reaction temperature is 120° C., and the reaction time is 6 h.
[0038] Put 22.8 g (0.1 mol) of 3,5-dichloro-2,4-difluoronitrobenzene, 10 g of 5% palladium-carbon catalyst, and 100 mL of DMF in a hydrogen absorbing reactor. Introduce hydrogen to carry out the hydrogenation reaction until no more hydrogen is absorbed. After filtration, the filtrate was distilled under reduced pressure to obtain 3,5-dichloro-2,4-difluoroaniline.
[0039] The synthesis operation of pyriobron was the same as in Example 1. The solvent was 60 mL of benzene, and the reaction was refluxed for 8 hours to obtain 34.5 g of white crystals with a yield of 90.6% and a melting point of 222.5-223.8°C.
Embodiment 3
[0041] The synthesis operation of 3,5-dichloro-2,4-difluoronitrobenzene is the same as in Example 1, the solvent is 100 mL of dimethylformamide (DMF), the reaction temperature is 140° C., and the reaction time is 7 hours.
[0042] Put 22.8g (0.1mol) of 3,5-dichloro-2,4-difluoronitrobenzene, 80mL DMF and 8g Raney nickel into the autoclave, seal it, feed hydrogen to 1.25MPa, heat up to 50°C, After reacting for 3 hours, cool, filter, and distill the filtrate under reduced pressure to obtain 3,5-dichloro-2,4-difluoroaniline.
[0043] The synthesis operation of pyriobron was the same as that in Example 1. The solvent was 60 mL of xylene, and the reaction was carried out under reflux for 6 hours to obtain 35.5 g of white crystals of pyrbendron with a yield of 93.2% and a melting point of 222.2-223.6°C.
PUM
| Property | Measurement | Unit |
|---|---|---|
| Melting point | aaaaa | aaaaa |
| Melting point | aaaaa | aaaaa |
Abstract
Description
Claims
Application Information
Login to View More