The synthetic method of flubenzuron intermediate 2-fluoro-4-(2-chloro-4-trifluoromethylphenoxy) aniline
A technology of trifluoromethylphenoxy and synthesis method is applied in the synthesis field of insect growth regulator flufenoxuron intermediate 2-fluoro-4-aniline, and can solve the problem of low content, unfavorable industrial production and low product yield and other problems, to achieve the effect of high product content, low raw material price and high total yield
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Embodiment 1
[0025] Add 39.7 g (0.3 mol) of 3-fluoro-4-aminophenol and 158.8 g of dichloroethane into a 250 ml four-necked flask equipped with a thermometer, a stirrer, and a cooling device, and stir to cool down to (10-20) °C. Control the temperature (10-20) ℃ and add 34 g (0.33 mol) of acetic anhydride dropwise for about 30 minutes. During the dropping process, the exotherm is violent. Keep the temperature at (10-20) ℃ for 2 hours until the reaction of the HPLC raw materials is completed. Control temperature (10-20) ℃ and add 30% sodium hydroxide aqueous solution dropwise to pH (5-6), filter, wash with 40 grams of water, and dry to obtain 49.6 grams of brown solid, content 97.9%, yield: 95.8%
Embodiment 2
[0027] Add 39.7 g (0.3 mol) of 3-fluoro-4-aminophenol and 158.8 g of dichloroethane into a 250 ml four-necked flask equipped with a thermometer, a stirrer, and a cooling device, and stir to cool down to (10-20) °C. Add 43.3 g (0.33 moles) of propionic anhydride dropwise under temperature control (10-20) °C, and drop it in about 30 minutes. During the dropping process, the exotherm is violent, and keep warm at (10-20) °C for 2 hours until the reaction of the HPLC raw materials is completed. Control temperature (10-20) ℃ and add 30% sodium hydroxide aqueous solution dropwise to pH (5-6), filter, wash with 40 grams of water, and dry to obtain 51.8 grams of brown solid, content 95.2%, yield: 89.8%
[0028] Preparation of Intermediate II 2-fluoro-4-(2-chloro-4-trifluoromethylphenoxy)acetanilide
Embodiment 3
[0030] Under nitrogen protection, DMSO 265 grams, potassium hydroxide 18.8 grams (0.333 moles), 3-fluoro-4-acetamidophenol Heat and stir 52.3 grams (0.303 moles) to (60-70) ℃ and keep it warm for 0.5 hours, then steam out about 30 grams of solvent with high vacuum (the measured water content is basically anhydrous), and the reaction liquid in the kettle is qualified if the water content is less than 1%. Afterwards, fill the air with nitrogen and add 72.3 g (0.333 moles) of 3.4-dichlorobenzotrifluoride at (60-70) ° C, continue to stir and heat to (110-120) ° C and keep it warm for 4 hours, and the HPLC raw material is reacted to <0.5% is qualified. After passing the test, cool down to (50-60)°C with negative pressure and high positive space to distill the solvent DMSO, evaporate about 80% and add 200 grams of water dropwise at (50-60)°C to produce a large amount of dark brown solid, filter 60 grams of water to wash Drained and dried to obtain 104.2 grams of dark brown solid, w...
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