92 results about "Trifluorotoluene" patented technology

The invention provides a synthesis method of 4-fluoro-2-trifluoromethyl acetophenone, which comprises the following steps: under protective gas, firstly adding a metal palladium catalyst, a ligand, alkali, an organic solvent, 2-bromo-4-fluorine-trifluorotoluene and methylboronic acid into a reactor, then introducing carbon monoxide gas into the reactor, raising the pressure of the reactor, and reacting for 2-4 hours at the temperature of between 20 and 30 DEG C; and heating and stirring until the reaction is complete, and carrying out post-treatment to obtain the product 4-fluoro-2-trifluoromethyl acetophenone. According to the method, the 4-fluoro-2-trifluoromethyl acetophenone is synthesized through the one-pot reaction of the 2-bromo-4-fluoro-trifluorotoluene and the methylboronic acid under the catalysis of the metal palladium catalyst, the reaction method is easy and convenient to operate, the target product can be efficiently synthesized only through one-step reaction, no waste water is generated in treatment after the reaction, and the method is green and environmentally friendly.

The invention discloses a perfluoropolyether-based polymer solid electrolyte film regulated and controlled by a mixed solvent as well as a preparation method and application of the perfluoropolyether-based polymer solid electrolyte film, and belongs to the field of organic polymer solid electrolyte preparation. Reacting under the action of an initiator and an RAFT (reversible addition-fragmentation chain transfer) reagent to obtain a perfluoropolyether-based copolymer; the method comprises the following steps: adding a perfluoropolyether-based copolymer into a polyvinylidene fluoride-hexafluoropropylene copolymer solution in which lithium salt is dissolved, the mass of the polyvinylidene fluoride-hexafluoropropylene copolymer accounts for 10%-30% of the mass of the polyvinylidene fluoride-hexafluoropropylene copolymer, the mass of the N, N '-dimethylformamide, the mass of the trifluorotoluene and the mass of the perfluoropolyether-based copolymer account for 10%-30% of the mass of the polyvinylidene fluoride-hexafluoropropylene copolymer, and the perfluoropolyether-based polymer solid-state electrolyte film is obtained by uniformly mixing and then preparing a film. And the comprehensive performance of the composite solid electrolyte serving as the film is improved.

The application discloses a continuous production process and equipment for a trifluoromethylbenzene tower, and belongs to the field of organic fluorine chemistry. The production process comprises the following steps: S1: continuously feeding trichloromethylbenzene and hydrogen fluoride into a tower reactor connected with a heat exchanger circulating cooling system in a reverse direction, so that a three-stage continuous fluorination reaction occurs in the tower reactor to obtain crude trifluoromethylbenzene, and unreacted hydrogen fluoride is separated into liquid at the top of the tower and then flows back into the tower reactor; S2: the crude trifluoromethylbenzene obtained in the reaction is subjected to nitrogen bubbling in a bubble tower, and then is continuously distilled in a rectifying tower to obtain finished trifluoromethylbenzene; and S3: byproduct hydrogen chloride generated in the fluorination reaction is introduced into a hydrochloric acid tank to obtain hydrochloric acid, and the content of hydrofluoric acid in the hydrochloric acid is less than 1000 ppm. The method can greatly improve the utilization rate of raw material hydrogen fluoride, improve the purity of byproduct hydrochloric acid, reduce the generation amount of waste acid, avoid the sharp change of pressure in the reaction process, and realize large-scale, continuous, stable and safe production of trifluoromethylbenzene.

The invention discloses a preparation method of fluazinam, which comprises the following specific steps: by taking anhydrous alkyl substituted aromatic hydrocarbon as a solvent, adding 2, 4-dichloro-3, 5-dinitro-trifluorotoluene and 2-amino-3-chloro-5-trifluoromethylpyridine to prepare a mixed solution; and preparing anhydrous alkyl substituted aromatic hydrocarbon containing an acid-binding agent, stirring for bottoming, and dropwise adding the mixed solution into the anhydrous alkyl substituted aromatic hydrocarbon to prepare fluazinam. According to the method, no water is generated in the reaction process, generation of by-products caused by hydrolysis of nitride raw materials is effectively prevented, post-treatment is convenient, the product does not need to be purified, the content can reach 99% or above, the yield can reach 99% or above, and industrial production of fluazinam is better facilitated.

The application provides a palladium ion extractant material and a preparation method thereof, and the pyridine-oxadiazole ligand is used as the extractant, most Pd 2+ in the aqueous phase can be extracted into the organic phase in a short time, and has a very high extraction rate; selective extraction separation of Pd 2+ under acidic conditions can be realized, the applicable range of acidity is wide, and excellent extraction capacity is achieved in the range of 0.2-4M nitric acid concentration; the extractant has excellent selectivity to Pd 2+ in the aqueous phase containing various metal ions; the pyridine-oxadiazole extractant has a good application prospect in the separation and recovery of Pd 2+ in high-level radioactive waste; the m-nitro-trifluorotoluene is used as a diluent of the extraction system, has good solubility to the organic ligand and the extractant, and the 2-bromohexanoic acid can increase the lipophilicity of the extractant.

The invention relates to the technical field of fine chemical engineering, in particular to a continuous preparation process of nitrobenzotrifluoride, which at least comprises the following steps: S1, adding fuming nitric acid into sulfuric acid to obtain a mixed acid solution; s2, a metering pump is used for controlling the flow speed of the mixed acid solution and trifluorotoluene, the mixed acid solution and the trifluorotoluene sequentially pass through the two-stage dynamic tubular reactor, and the temperature of materials in the two-stage dynamic tubular reactor is controlled through external circulation; and S3, dropwise adding the mixture obtained after the reaction in the step S2 into water for quenching, then carrying out phase splitting, taking an upper-layer oil phase as a nitrobenzotrifluoride crude product, carrying out water washing and alkali washing to obtain nitrobenzotrifluoride, taking a lower-layer dilute sulphuric acid solution, further concentrating, and then applying in the next batch of nitration reaction, so that the online material quantity of the reaction is reduced, and the safety risk caused by thermal runaway of the reaction is avoided. Meanwhile, the concentration of sulfuric acid is reduced, so that the sulfuric acid is easier to recycle and reuse.

The invention discloses a synthesis method of Olrabatinib, which comprises the following steps: by taking 2-methyl-5-nitro trifluorotoluene as a raw material, carrying out a Waller-Ziegler reaction, an alkylation / silanization reaction of amine, nitro reduction, a condensation reaction and a Caslow-Stevens coupling reaction, so as to obtain the Olrabatinib. By optimizing process conditions and a reaction system, the synthesis method disclosed by the invention has the remarkable advantages in the following aspects: the raw material cost is greatly reduced by adopting low solvent consumption; the product yield is improved by accurately controlling reaction parameters; a standardized post-treatment process is developed, and large-scale stable production is realized. According to the technical system, the technical bottlenecks of high energy consumption and high pollution in the traditional synthesis route are effectively solved, and an innovative solution is provided for green manufacturing of fine chemicals.

The invention relates to an electron withdrawing group terminated polyimide covalent organic framework material as well as a preparation method and application thereof. According to the invention, 4, 4 '-(hexafluoroisopropenyl) diphthalic anhydride and a tetra (4-aminophenyl) methane monomer are utilized to prepare a polyamic acid covalent organic framework, and 4-cyanophenyl, 4-aminotrifluorotoluene, 4-nitroaniline and 4-chloroaniline are utilized to perform end capping, so that the electron withdrawing group-terminated polyimide covalent organic framework material is prepared. The rich pore structure of the COF skeleton provides a rapid ion transport channel, the transport of current carriers is promoted, and the electron cloud density of the COF skeleton is adjusted through Lewis acidity formed by an end-capping electron withdrawing group through an induction effect, so that an electron-deficient domain is constructed. When being used in a lithium metal battery system, the material can guide uniform distribution of lithium ions and solve the problem of lithium dendrite growth; when the material is loaded on a lithium-sulfur battery positive electrode material, polysulfide can be pulled to move directionally to complete order reduction conversion reaction, so that the lithium-sulfur battery with long cycle life is obtained.

This invention belongs to the field of organic synthesis and discloses a method for preparing 2-bromo-5-fluorotrifluorotoluene, comprising: controlling the temperature at 5-20℃, mixing m-fluorotrifluorotoluene with sulfuric acid, adding a composite catalyst, and then adding NBS in batches. After the NBS addition is completed, the reaction is maintained at this temperature until the m-fluorotrifluorotoluene content is ≤1%, at which point the reaction is stopped; the reaction solution is allowed to stand and separate into layers to obtain crude 2-bromo-5-fluorotrifluorotoluene; the crude 2-bromo-5-fluorotrifluorotoluene is then subjected to alkali washing and water washing, followed by atmospheric distillation, collecting the fraction at 158-165℃ to obtain the 2-bromo-5-fluorotrifluorotoluene product; the composite catalyst is a mixture of elemental iodine, zinc bromide, and tetrabutylammonium bromide. This method involves only one reaction step, is simple to operate, has accurate reaction positioning, high raw material conversion rate, high reaction yield, easy product purification, and simple post-processing. The reaction yield can reach over 93.0%, and the purity is over 98.0%.

The invention relates to the field of organic synthesis, and discloses a preparation method of a flufenoxuron intermediate. According to the preparation method disclosed by the invention, 3-fluoro-4-acetaminophenol and 3-chloro-4-fluorobenzotrifluoride are taken as reaction raw materials, and an isomer impurity 4-(5-trifluoromethyl-2-chlorophenoxy)-2-fluoroaniline which is difficult to separate is not generated. When the Williamson reaction is carried out, the No.4 site of the 3-chloro-4-fluorobenzotrifluoride is a fluorine element, so that the 3-fluoro-4-acetaminophenol can be better positioned and then substituted, the reaction efficiency is higher, the reaction is more complete, and the yield is higher. The purity of the product 2-fluoro-4-(2-chloro-4-trifluoromethylphenoxy) acetanilide (an intermediate of the target product 4-(4-trifluoromethyl-2-chlorophenoxy)-2-fluoroaniline) in the step is higher, and the purity of the target product 4-(4-trifluoromethyl-2-chlorophenoxy)-2-fluoroaniline is finally improved.

This invention discloses a method for synthesizing monosubstituted sulfonylamidinium compounds. In an air atmosphere, using commercially available primary sulfonamides and nitriles as substrates, inexpensive trifluoromethanesulfonic anhydride as a catalyst, and trifluorotoluene as a solvent, the product can be efficiently obtained. Compared with existing technologies, this method has the following advantages: inexpensive and readily available reactants; no need for cumbersome synthesis methods; simple reaction system; high atom economy with 100% atom utilization; broad substrate range, compatible with various functional groups; and simple operation.

The present invention belongs to the field of chemical analysis and testing, and particularly relates to a coumarin-based fluorescent probe derived from trifluorotoluene and its application. 7-Hydroxycoumarin-4-acetic acid and p-bromotrifluorotoluene are dissolved in dimethyl sulfoxide solution, and the reaction solution is heated under reflux at 70-90 °C for 3-4 hours under the alkaline condition of potassium carbonate. The obtained crude product is separated and purified by thin layer chromatography to obtain the coumarin-based fluorescent probe SYL-3 derived from trifluorotoluene. The coumarin-based fluorescent probe obtained in the present invention can rapidly identify cadaverine (Cad) in an aqueous solution of cetyltrimethylammonium bromide (CTAB) surfactant.

The research aims to optimize the synthesis process of oxyfluorfen, improve the product yield and purity, and turn byproducts into wealth. According to an original process route, resorcinol is used as a starting raw material, and oxyfluorfen is synthesized through double etherification, nitration and ether exchange. After optimization, the total yield reaches 94.1%, and the purity reaches 98.4%. In order to improve the utilization rate of the raw materials, an acidic water phase obtained after quenching of an oxyfluorfen reaction solution is subjected to reduced pressure distillation, the byproduct 3-chloro-4-hydroxy-trifluorotoluene is recovered, and the yield can reach 93.7%. Further serving as a raw material of a new process, and synthesizing a target product through nucleophilic substitution. In the route, 2, 4-dichloronitrobenzene with moderate reaction activity and better selectivity is innovatively used for replacing 2, 4-difluoronitrobenzene, so that side reaction is effectively inhibited, and a target product with the content of 98.7% is obtained at the total yield of 94.8%. According to the new and old combination strategy, through integration of two process routes, high-valued conversion of by-products is realized, limitation of a traditional synthesis method is broken through, and atom economy is remarkably improved.

The invention provides a preparation method of 2-bromine-5-fluorobenzotrifluoride and a preparation method of the 2-bromine-5-fluorobenzotrifluoride. Specifically, the invention provides a preparation method of a compound as shown in a formula E. The preparation method comprises the following steps: reacting a compound as shown in a formula A with urea to generate a compound as shown in a formula B; in an organic solvent, carrying out substitution reaction on the compound as shown in the formula B and bromine to generate a compound as shown in a formula C; carrying out hydrolysis reaction on the compound as shown in the formula C in an alkaline solution to generate a compound as shown in a formula D; and carrying out diazotization reaction on the compound shown in the formula D, HF and nitrite to generate a compound shown in a formula E. According to the preparation method, the reaction steps are simplified, the bromination selectivity is high, and the production cost can be effectively reduced.

The invention relates to a method for preparing 5-fluoro-2-bromobenzotrifluoride through bromination, and relates to the technical field of organic synthesis.The method comprises the following steps that fluorobenzotrifluoride, an acid medium and a catalyst are added into a solvent, bromine is added at the temperature of-10 DEG C to 60 DEG C, the dropwise adding time is 1-6 h, heat preservation is conducted, a bromination reaction is conducted for 2-24 h, and reaction liquid is obtained; the acid medium comprises chlorosulfonic acid; the solvent comprises any one or two of dichloromethane, dichloroethane, trichloromethane and tetrachloromethane; the catalyst comprises any one or two of sulfur, sodium sulfide and potassium sulfide; filtering the reaction liquid, and standing and separating the filtrate to obtain an organic phase; the filter cake is a catalyst and can be repeatedly used; distilling and concentrating the organic phase to obtain a concentrated solution; and carrying out rectification separation on the concentrated solution to obtain the 5-fluoro-2-bromobenzotrifluoride. The method has the advantages of few reaction steps, simplicity in operation and environmental friendliness, and the product has high yield and high purity.

The invention belongs to the technical field of organic fluorine compounds, and particularly provides a continuous preparation method of 3-nitro-4-cyanobenzotrifluoride, which comprises the following steps: S1, introducing 3-nitro-4-methylbenzotrifluoride, bromine and a free radical initiator into a first continuous reactor containing a brominated anhydrous solvent to generate 3-nitro-4-bromomethyl benzotrifluoride; s2, introducing the 3-nitro-4-bromomethyl benzotrifluoride obtained in the S1 and cuprous cyanide into a second continuous reactor containing a cyaniding anhydrous solvent to generate a 3-nitro-4-cyano benzotrifluoride crude product, filtering, separating out a copper-containing filter cake, and distilling the obtained filtrate to obtain the 3-nitro-4-cyano benzotrifluoride crude product; s3, carrying out regeneration cycle on the copper-containing filter cake; and S4, carrying out reduced pressure distillation on the crude product obtained in the S2 to obtain the high-purity 3-nitro-4-cyano trifluorotoluene. Through the steps, cuprous cyanide regeneration can be realized, and efficient utilization of resources is realized.

The invention relates to a preparation method of 1-fluoro-3-iodine-5-(trifluoromethyl) benzene. The 1-fluoro-3-iodine-5-(trifluoromethyl) benzene is used as a raw material. The preparation method of the 1-fluoro-3-iodine-5-(trifluoromethyl) benzene comprises the following steps: mixing 3-bromo-5-fluorobenzotrifluoride, iodized salt, a catalyst and an active agent, and then carrying out a reaction, so as to obtain the 1-fluoro-3-iodine-5-(trifluoromethyl) benzene, the active agent is trans-(1R, 2R)-N, N '-dimethyl-1, 2-cyclohexane diamine. The preparation method provided by the invention is simple and convenient to operate, the synthetic raw materials are economical and easy to obtain, and the 1-fluoro-3-iodine-5-(trifluoromethyl) benzene with excellent yield and purity can be efficiently obtained.

The invention provides trifluorotoluene continuous production equipment and process, and relates to the technical field of organic chemical engineering, the trifluorotoluene continuous production equipment comprises a first mixing mechanism, the first mixing mechanism comprises a first mixing cylinder, the top of the first mixing cylinder is fixedly provided with a first sealing cover, and the bottom of the first sealing cover is fixedly provided with a hollow telescopic rod; the bottom of the hollow telescopic rod is fixedly provided with a heating disc, the center of the heating disc is fixedly provided with a U-shaped valve, the top of the heating disc is fixedly provided with a plurality of first heating rods, the bottom of the hollow telescopic rod is fixedly provided with a first gas conveying pipeline, and the first gas conveying pipeline is connected with an external gas conveying pump. The situation that the pipeline is blocked by sediments and the production smoothness is influenced can be avoided, and continuous production of trifluorotoluene is facilitated; the sealing device has good sealing performance, enough pressure can be kept in the machining process of materials, and the production efficiency of trifluorotoluene is improved.

The utility model discloses a rectifying tower for trifluorotoluene reaction, which comprises a tower body, a feed inlet is arranged in the middle of the tower body, a liquid phase outlet and a steam reflux inlet are arranged at the bottom end of the tower body, and both the liquid phase outlet and the steam reflux inlet are connected with a reboiler. According to the utility model, the tower body, the feeding hole, the liquid phase outlet, the steam reflux inlet, the gas phase outlet, the condensation reflux pipe and the spraying mechanism are arranged, and the spraying mechanism comprises a middle pipe, a rotating pipe, a spray head, a motor, a worm, a worm gear and a booster pump, condensed liquid-phase raw materials in the condenser can be pressurized and pumped into the rotating pipe again through the booster pump and sprayed into the tower body through the spray head, and meanwhile, the rotating pipe is driven by the motor to rotate in the tower body, so that rising steam in the tower can be in full contact with a liquid phase sprayed by the spray head for heat exchange, light components in the liquid phase are accelerated to enter a gas phase, and the heat exchange efficiency is improved. And heavy components in a gas phase enter a liquid phase, so that the production efficiency is improved.

The invention discloses a method for preparing 2,4,5-trifluorophenylacetic acid, and relates to the technical field of organic chemical industry. Aluminum chloride is added to 1,2,4-trifluorobenzene, methyl bromide is introduced under stirring to react, a solvent and sodium hydrogen are continuously added to the obtained 2,4,5-trifluorotoluene, carbon dioxide is continuously introduced, and reacted at 25-35 DEG C to obtain 2,4,5-trifluorophenylacetic acid sodium, filtered, quenched, and then adjusted to pH below 2 with 30%wt hydrochloric acid, and 2,4,5-trifluorophenylacetic acid solid is obtained by filtration. The whole reaction process is simple to operate, the reaction conditions are mild, the environmental pollution is small, it is suitable for industrial production, and the yield and purity of the product are high.

The invention belongs to the field of analytical chemistry, and particularly relates to a method for determining 4-(4-amino-3-fluorophenoxy) pyridine-2-carboxylic acid methylamine and 2-chloro-5-aminobenzotrifluoride in a medicine, the determination method is a liquid chromatography, a C8 chromatographic column is adopted, a mobile phase A is selected from a phosphate solution, a mobile phase B is selected from a nitrile solvent, and gradient elution is carried out. The detection method has good specificity, repeatability and accuracy and high sensitivity, can effectively and accurately perform qualitative and quantitative analysis on the compound, and ensures safety and effectiveness of medicine quality.

The invention discloses a method for continuously preparing 4-fluoro-2-trifluoromethyl acetophenone, which comprises the following steps of: pre-filling a magnesium metal bed layer in a Grignard reactor, respectively feeding a 2-bromine-5-fluorobenzotrifluoride solution and magnesium metal from the bottom and the top of the Grignard reactor, introducing inert gas from the bottom of the Grignard reactor, and continuously reacting at the temperature of between 20 and 30 DEG C to obtain 4-fluoro-2-trifluoromethyl acetophenone. After being distributed by the microporous disperser, the gas uniformly enters the Grignard reactor from bottom to top, and the gas discharged from a gas outlet in the top of the Grignard reactor is re-introduced into the bottom of the Grignard reactor; reaction liquid obtained after the Grignard reaction is completed flows out and then is divided into two parts, a small part of the first part returns to the bottom of the Grignard reactor to serve as an initiator of the Grignard reaction, and a large part of the second part is sequentially subjected to acylation reaction and acidolysis reaction and then is subjected to post-treatment, so that the target product 4-fluoro-2-trifluoromethyl acetophenone is obtained. The method has the advantages of high reaction efficiency, simple system, low cost and the like, and industrial production is easy to realize.

The present invention provides a process (100) for the preparation of m-hydroxybenzotrifluoride (MHBTF) in a batch mode, which achieves a high yield of 98 to 99% and a purity of 99.1 to 99.9%. The method (100) may include a first stage of treating and diazotizing (A) 3-aminohydroxytrifluorotoluene with sulfuric acid (H2SO4) to obtain a diazotized sulfate of 3-aminohydroxytrifluorotoluene. Further, the second stage B may include hydrolyzing the diazotized sulfate of 3-aminotrifluorotoluene in the presence of toluene to obtain crude m-hydroxytrifluorotoluene (MHBTF), and further recovering and reusing the acid effluent (sulfuric acid) consumed in the first stage of the process of preparing m-hydroxytrifluorotoluene. Stage B may include separating the crude m-hydroxybenzotrifluoride in the organic layer from the aqueous layer by alkali wash of the organic layer. The third stage C may include distilling the organic layer to obtain pure m-hydroxybenzotrifluoride.

The invention relates to the technical field of finish paint, and discloses quick-drying corrosion-resistant finish paint and a preparation process thereof, the quick-drying corrosion-resistant finish paint is composed of a component A and a component B, wherein the component A is prepared from the following raw materials: epoxy acrylate resin, anti-corrosion resin, sulfhydrylated dickite, a defoaming agent, an antioxidant, an emulsifying agent and a flatting agent; the component B comprises the following raw materials: a photoinitiator and deionized water; wherein the anti-corrosion resin is prepared by reacting modified vinyl chloride-vinyl acetate resin with 2-amino-5-fluorobenzotrifluoride; the modified vinyl chloride-vinyl acetate resin is prepared by reacting hydroxyl vinyl chloride-vinyl acetate resin with 2-chloroacrylic acid; the sulfhydrylated dickite is prepared by reacting the modified dickite with mercaptoethylamine; the modified dickite is prepared by intercalating (3-carboxypropyl) trimethyl ammonium chloride into dickite. The finish paint prepared by the invention has excellent quick-drying property, wear resistance and corrosion resistance, and the application field of the finish paint is greatly expanded.

The invention discloses a triaryl phosphine ligand as well as a preparation method and application thereof, belongs to the technical field of chemical engineering, and solves the problem that the action efficiency of a catalyst is not ideal enough in a reaction for generating 1-methoxy-2, 7-octadiene through telomerization of 1, 3-butadiene and methanol catalyzed by palladium in the prior art. The preparation method comprises the following steps: in a water-free and oxygen-free environment, dissolving brominated benzotrifluoride in diethyl ether, dropwise adding n-butyllithium at the temperature of-5 to 5 DEG C, and fully stirring to obtain a lithium reagent; the preparation method comprises the following steps: adding chlorodiaryl phosphorus into a lithium reagent, mixing and stirring, heating to 20-30 DEG C in stages, continuously stirring and reacting under an anaerobic condition, and recrystallizing to obtain the triarylphosphine ligand. The palladium catalytic system obtained by the preparation method is high in 1, 3-butadiene conversion rate, better in ligand selectivity and lower in catalyst concentration, and can be used for industrial production of 1-MOD.

The invention relates to the technical field of preparation of intermediates, in particular to the field of IPCC07C45, and more particularly relates to a synthetic method of meconazole. The synthesis method of the meconazole comprises the following steps: firstly preparing an aryl Grignard reagent from 2-bromo-5-fluorine-benzotrifluoride as an initial raw material, then reacting the aryl Grignard reagent with bromoacetone, and then sequentially carrying out ring-opening substitution and etherification reaction to obtain the meconazole, and the synthesis route is as shown in a formula 1: # imgabs0 #. 2-bromo-5-fluorobenzotrifluoride is prepared into an aryl Grignard reagent, then the aryl Grignard reagent and bromoacetone are subjected to nucleophilic addition reaction, ring closing is further carried out, the original two-step reaction of acetylation and epoxy is combined into one-step reaction, and the synthesis method is simplified.

This invention relates to the field of acyclic or carbocyclic compounds and discloses a method for preparing 6-bromo-2,3-difluorotrifluorotoluene, comprising: dissolving 2,3-difluorotrifluorotoluene in a mixed solvent composed of a polar modifier containing a proton acceptor site and a nonpolar solvent; adding a polyether stabilizer and an iron-based catalyst; and dropwise adding liquid bromine to trigger a directional bromination reaction. The method utilizes the protonated ion-pair complex formed by the in-situ generation of hydrogen bromide and the polar modifier, which, in conjunction with the polyether stabilizer, constructs a sterically hindered shielding structure at positions 4 and 5 of the substrate molecule. This invention forces the electrophilic substitution pathway to be directed towards position 6 of the substrate molecule, overcoming the bottleneck of extremely low positioning accuracy in passivated aromatic ring systems, transforming disordered isomers into a single dominant isomer, thereby reducing separation energy consumption.

The present invention relates to an improved process for the preparation of 2-bromo-5-fluorobenzotrifluoride comprising, reacting 3-fluorobenzotrifluoride with brominating agent in the presence of antimony catalyst selected from antimony trichloride (SbCl3), antimony pentachloride (SbCl5) or mixture(s) thereof, to provide 2-bromo-5- fluorobenzotrifluoride with higher yield and purity

The invention relates to a preparation method of 3-bromobenzotrifluoride, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: taking benzotrifluoride as a raw material, and reacting with liquid bromine under the action of a catalyst and a complexing agent to obtain 3-bromobenzotrifluoride; the catalyst is iron powder, ferric trichloride or ferric tribromide; the complexing agent is at least one of methanol, ethanol, methyl tertiary butyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, acetone or sodium acetate. The compound containing lone pair electrons is added into the reaction liquid to form a complex with ferric iron, so that the activity of the ferric iron catalyst is reduced, and the situation that the bromine substitution selectivity is reduced due to too high activity is avoided; the selectivity of aromatic ring bromine meta-substitution is improved, the generation of para-bromine substituted isomers and polysubstituted impurities is reduced, and the purity and yield of the product are improved.

The present invention relates to the technical field of topcoats, and discloses a quick-drying corrosion-resistant topcoat and a preparation process thereof. The quick-drying corrosion-resistant topcoat is composed of component A and component B; wherein component A includes the following raw materials: epoxy acrylate resin, anti-corrosion resin, mercapto-dimethylbenzene, defoamer, antioxidant, emulsifier, and leveling agent; component B includes the following raw materials: photoinitiator and deionized water; wherein the anti-corrosion resin is prepared by reacting a modified chloroacetic acid resin with 2-amino-5-fluorobenzotrifluoride; the modified chloroacetic acid resin is prepared by reacting a hydroxychloroacetic acid resin with 2-chloroacrylic acid; the mercapto-dimethylbenzene is prepared by reacting a modified dimethylbenzene with mercaptoethylamine; and the modified dimethylbenzene is prepared by intercalating dimethylbenzene with (3-carboxypropyl)trimethylammonium chloride. The topcoat prepared by the present invention has excellent quick-drying properties, wear resistance, and corrosion resistance, greatly expanding the application field of the topcoat.