Preparation method of 3, 5-dichloro-4-fluorobromobenzene compound
A technology for fluorobromobenzene and dichloride, which is applied in the field of preparation of 3,5-dichloro-4-fluorobromobenzene compounds, can solve the problems of difficult preparation, high synthesis cost, low product yield and the like, and is beneficial to industrialization , the effect of improving the yield and the easy availability of raw materials
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[0044] Example 1: Preparation of 2,4-dichloro-3-fluoronitrobenzene
[0045] Throw in 330g (2mol) of 2,6-dichlorofluorobenzene in the reactor, be warming up to 40°C, add dropwise the mixed acid of 400g (4mol) of prepared sulfuric acid and 195g (3mol) of nitric acid, dripping is completed, keep warm at this temperature 2h, sampling and control, the reaction is completed, stand for stratification, the oil layer is neutralized, washed with water, and layered, the obtained oil layer is cooled to about 5 ℃ and kept for 5 hours, then the oil layer is released, the obtained solid is heated and dissolved, and then cooled to about 5 ℃ and kept warm After 5 hours, the upper layer liquid was poured out, and the lower layer solid was 360 g of 2,4-dichloro-3-fluoronitrobenzene, with a purity of 99.5% and a yield of 85.3%.
[0046]Drop into 2,6-dichlorofluorobenzene 330g (2mol) in the reactor, be warming up to 60 ℃, add the mixed acid of prepared sulfuric acid 400g (4mol) and nitric acid 195...
Example Embodiment
[0047] Example 2: Preparation of 2,4-dichloro-3-fluoroaniline
[0048] Put 2,4-dichloro-3-fluoronitrobenzene 315g (1.5mol), methanol 600g, palladium carbon 3g into the autoclave, close, heat up to 50°C, pass hydrogen pressure to 2MPa, keep warm for 2h, control in the middle, and react After completion, it was cooled to room temperature, filtered and concentrated to obtain 245 g of 2,4-dichloro-3-fluoroaniline with a purity of 99% and a yield of 89.8%.
[0049] Put into the autoclave 315g (1.5mol) of 2,4-dichloro-3-fluoronitrobenzene, 600g of ethyl acetate, 3g of palladium carbon, close, heat up to 50°C, pass hydrogen pressure to 2MPa, keep warm for 2h, and control the , the reaction was completed, cooled to room temperature, filtered and concentrated to obtain 239 g of 2,4-dichloro-3-fluoroaniline with a purity of 99% and a yield of 87.6%.
[0050] Put 315g (1.5mol) of 2,4-dichloro-3-fluoronitrobenzene, 600g of methanol, and 3g of platinum carbon into the autoclave, close it,...
Example Embodiment
[0052] Example 3: Preparation of 3,5-dichloro-4-fluorobromobenzene
[0053] Put into the reactor 500 ml of water, 180 g (1 mol) of 2,4-dichloro-3-fluoroaniline, and control the temperature in the reactor to add dropwise 450 g of sulfuric acid (the mass concentration is 98%, 4.5 mol) at 25 to 30 °C. ), and the temperature in the reactor was controlled to react at 25-30° C. for 1 hour after the addition was completed.
[0054] The temperature in the control reactor is 35~40 ℃, drips 79.9 grams (0.5mol) of bromine, the time for adding is about 4 hours, then controls the temperature in the reactor to be 35~40 ℃ drip hydrogen peroxide 100.0 grams (mass concentration is 17%, 0.5mol), the dropwise addition time was controlled at 2-2.5 hours, and the reaction was kept warm after the dropwise addition. Incubate the reaction for 2 to 3 hours.
[0055] The temperature in the reactor was lowered to -10~0°C, 240g (4mol) of isopropanol was added, 10g of cuprous oxide was added after dropp...
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