Preparation method of 3,5-dichloro-4-fluorobromobenzene compound
A technology of fluorobromobenzene and dichlorobenzene, which is applied in the field of preparation of 3,5-dichloro-4-fluorobromobenzene compounds, can solve the problems of low product yield, difficult preparation, and high synthesis cost, and achieve easy synthesis of raw materials The effect of gaining, cheap price and reducing reaction loss
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Embodiment 1
[0036] Embodiment 1: Preparation of 2-fluoro-3-chloro-5-bromonitrobenzene
[0037] Put 702g (4mol) of 2-fluoro-3-chloronitrobenzene and 325g (2mol) of ferric chloride into a 1L four-necked bottle, raise the temperature to 40°C, add 960g (6mol) of bromine dropwise, and keep warm at this temperature after dropping After 5 hours, sampling was carried out in the control center. After the reaction was completed, water was added, layers were separated, neutralized, and washed with water to obtain 965 g of oil layer with a purity of 95.5% and a yield of 90.6%.
[0038] Put 702g (4mol) of 2-fluoro-3-chloronitrobenzene and 267g (2mol) of aluminum trichloride into a 1L four-neck bottle, raise the temperature to 40°C, add 960g (6mol) of bromine dropwise, and keep warm at this temperature after dropping After 5 hours, sampling was carried out in the control center. After the reaction was completed, water was added, layers were separated, neutralized, and washed with water to obtain 905 g ...
Embodiment 2
[0041] Embodiment 2: Preparation of 2-fluoro-3-chloro-5-bromoaniline
[0042] Put 509g (2mol) of 2-fluoro-3-chloro-5-bromonitrobenzene into a 3L autoclave, 2036g of methanol, and 10g of catalyst platinum carbon, raise the temperature to 30°C, pass the hydrogen gas at 1MPa, keep it warm for 2h, and control the sample. After the reaction was completed, the temperature was lowered to room temperature, filtered, and concentrated to obtain 405 g of 2-fluoro-3-chloro-5-bromoaniline with a purity of 98% and a yield of 88.4%.
[0043] Put 509g (2mol) of 2-fluoro-3-chloro-5-bromonitrobenzene into a 3L autoclave, 2036g of ethyl acetate, 10g of catalyst platinum carbon, raise the temperature to 30°C, pass the hydrogen pressure to 1MPa, keep it warm for 2h, and take a sample After the reaction was completed, the temperature was cooled to room temperature, filtered, and concentrated to obtain 395 g of 2-fluoro-3-chloro-5-bromoaniline, with a purity of 97.6% and a yield of 85.9%.
[0044]P...
Embodiment 3
[0047] Embodiment 3: Preparation of 3,5-dichloro-4-fluorobromobenzene
[0048] Put 224.5g (1mol) of 2-fluoro-3-chloro-5-bromoaniline into a 2L four-necked bottle, 608g (5mol) of hydrochloric acid and 300g of water, cool down to 10°C, add dropwise 103.5g (1.5mol) of sodium nitrite and A solution of 200 g of water was added to obtain diazonium solution after dropping. Put 300g of hydrochloric acid and 100g of cuprous chloride into another 2L four-necked bottle, raise the temperature to 50°C, add the stepping diazonium solution dropwise, keep warm at this temperature for 5h after dropping, control the sample in the middle, after the reaction is completed, cool down to room temperature, and statically Separate the layers, neutralize the oil layer, wash with water, separate the layers, and then rectify to obtain 203 g of 3,5-dichloro-4-fluorobromobenzene with a purity of 99.8% and a yield of 83.1%.
[0049] Put 224.5g (1mol) of 2-fluoro-3-chloro-5-nitroaniline, 973g (8mol) of hydr...
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