Background and overview[1][2]
Trifluoromethoxybenzene is a benzene derivative that can be used in pesticides, medicines and liquid crystals. Medicines synthesized using fluorine-containing organic compounds as raw materials have many advantages: for example, they can enhance the properties of medicines, have high efficacy, and It has no other side effects, and it also has the characteristics of durability and good oral administration. In recent years, this organic compound has been widely used.
Preparation[1]
1. Chlorination reaction
Add 150g of p-chlorotrifluorotoluene solvent into a 1000ml reactor equipped with mechanical stirring, condenser tube, thermometer, bottom vent tube, and dropper tube, start stirring, and raise the temperature to 139~140°C until the solvent refluxes. When the temperature is high, pass the chlorine gas and start to add dropwise a mixed solution of 200g anisole, 600g p-chlorotrifluorotoluene solvent and 10g azobisisobutyronitrile initiator. Add dropwise at 139~140°C for about 12 hours. After the dropwise addition is completed, After sampling and analysis, when dichloromethoxybenzene is lower than 0.3%, stop the reaction and cool down.
2. Fluorination reaction
Add 1134.5g of the mixed solution obtained by the chlorination reaction into a 1L autoclave, add 133.3g of hydrogen fluoride, start stirring, raise the temperature to 95°C, and keep the reaction under 2.8Mpa pressure for 3 to 4 hours. Stop the reaction and take samples for analysis.
3. Product separation
Wash the reaction product with water, separate the layers, and remove the oil phase liquid for distillation. Distillate at -0.095Mpa～-0.1Mpa, 40℃. The solvent p-chlorobenzotrifluoride was 719.7g, the purity was 99.13%, and the solvent recovery rate was 95.12%; the trifluoromethoxybenzene 286.38g was obtained, the purity was 99.95%, and the trifluoromethoxybenzene yield was 95.46%.
Apply[2]
p-Nitrotrifluoromethoxybenzene is the raw material for the synthesis of p-trifluoromethoxyaniline, and p-trifluoromethoxyaniline, as a fluorine-containing organic intermediate, can be widely used in pesticides, medicines, and liquid crystal materials. , such as used to synthesize various pesticides, herbicides, electrophotographic materials, active optical fibers, and used to synthesize medicines for the treatment of cardiovascular disease and diabetes. A method for nitration of trifluoromethoxybenzene. Pure trifluoromethoxybenzene is used as the raw material, and a mixed acid of fuming nitric acid and concentrated sulfuric acid is used as the nitrating agent. The two are strongly mixed in the microchannel reactor through continuous conveying equipment. Preferably, the mixed material is further Mix and react in the second reactor at the rear of the microchannel reactor to obtain the product trifluoromethoxynitrobenzene. This method utilizes the high-efficiency mass and heat transfer characteristics of the microchannel reactor. Under the optimized structure and operating parameters of the microreactor, more than 99% of the raw materials can be converted and p- and ortho-nitrotrifluoromethoxy groups can be generated with high selectivity. Benzene, meta and dinitration by-products are below 0.1% and 1% respectively.
Main reference materials
[1] [China invention, China invention authorization] CN201610334830.7 A production method of trifluoromethoxybenzene
[2] [Chinese invention, Chinese invention authorization] CN201610218214.5 A method for nitration of trifluoromethoxybenzene
