222 results about "Dichloroethane" patented technology

The invention relates to a preparation method of a lithium difluoro bis (oxalate) phosphate concentrated solution, and belongs to the technical field of lithium battery electrolyte additives. Adding lithium oxalate into a solvent, stirring and dissolving to obtain a lithium oxalate solution; the method comprises the following steps: adding a modified fluorine ion chelating agent into a lithium oxalate solution, stirring, filtering, putting into a reactor, and slowly introducing phosphorus pentafluoride gas; after the introduction is finished, heating and stirring for reaction; after the reaction is finished, filtering reaction liquid to remove unreacted solid impurities, so as to obtain a lithium difluoro bis (oxalate) phosphate concentrated solution; the modified fluorine ion chelating agent is prepared from D301 ion exchange resin, dichloroethane, propylene-1-base boronic acid pinacol ester, mercaptoethyl guanidine dihydro bromide and sodium tert-butoxide. The lithium difluoro bis (oxalate) phosphate prepared by the method is high in purity and high in yield, and meets the use requirements of lithium ion battery electrolyte on lithium salt.

The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of an isoxazole compound under a visible light catalysis condition. The method comprises the following steps: dissolving a compound 1 in 1, 2-dichloroethane, then adding tert-butyl nitrite, tribromomethane, alkali and a photocatalyst, in an inert gas environment, irradiating with visible light and stirring at room temperature to react, after the reaction is completed, reducing pressure to remove a solvent, and then performing silica gel column purification on a crude product to obtain a product, namely the isoxazole compound. The brand-new method for preparing the isoxazole compound through visible light catalysis is developed, the conditions of high temperature and high pressure in a traditional synthesis method are avoided, energy consumption and environmental pollution are remarkably reduced, and the yield of the isoxazole compound is effectively increased by regulating and controlling reaction conditions and optimizing raw material selection and proportion.

The invention discloses a Pd-Ba / C catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: step 1, pretreating a carbon carrier; step 2, preparing a complexing solution containing a barium complex; step 3, carrying out wet impregnation to obtain a carbon carrier adsorbed with a barium complex; 4, performing low-temperature pyrolysis to obtain a barium pre-modified carrier; 5, a complexing solution containing palladium and barium complexes is prepared; step 6, co-adsorption of bimetals is realized through wet impregnation, and a bimetal adsorption carrier is obtained; step 7, freeze drying; 8, the precursor obtained after freeze drying is subjected to hydrogen reduction, and the Pd-Ba / C catalyst is obtained. The invention provides application of the Pd-Ba / C catalyst in preparation of ethylene by hydrodechlorination of 1, 2-dichloroethane. According to the invention, pre-loaded barium occupies a strong adsorption site on the surface of the activated carbon, so that the stability and dispersity of a palladium active center can be enhanced, and synergistic improvement of chlorine poisoning resistance and catalytic performance of the catalyst is realized.

The invention belongs to the technical field of synthesis of organic compounds, and particularly relates to a process for preparing fipronil and an intermediate thereof. Toxic 1, 2-dichloroethane is comprehensively replaced by bio-based gamma-valerolactone, low-toxicity cyclopentyl methyl ether is matched, and N, N-dimethylformamide necessary for the process is recycled, so that consumption is greatly reduced; the continuous processes of amination, diazotization and the like are realized through a tubular reactor, a micro-reactor and a static mixer, and separation technologies such as pervaporation membrane and vacuum distillation are combined, so that the reaction time is shortened, the solvent recovery rate is increased, and the production is promoted to be continuously transformed to green. The supported FeCl3 / SiO2-NH2 catalyst disclosed by the invention can be repeatedly used, and byproducts and tail gas can be recycled and reused. In addition, diazonium salt residues are controlled to be smaller than or equal to 0.5% through near infrared spectroscopy, citric acid is subjected to stable oxidation reaction, a purification process is combined, it is ensured that the finished product is high in purity, excellent in yield and small in batch fluctuation, and efficiency and safety are both considered.

The invention relates to the field of chemical equipment, in particular to a 1-nitroanthraquinone continuous production process based on a dynamic liquid membrane continuous flow reactor, which comprises a solid feeding device, a homogeneous emulsifier, a quenching kettle, a solid-liquid separator, a centrifugal separator and a dynamic liquid membrane reactor, a sulfuric acid storage tank is divided into two branches through a sulfuric acid feeding pump, one branch is connected to the dynamic liquid membrane reactor, the other branch is connected to the dynamic liquid membrane reactor through a flow self-control valve, the quenching kettle is connected to a solid-liquid separator, the solid-liquid separator is divided into two branches, one branch is connected to an anthraquinone crude product storage tank, the other branch is connected to a centrifugal separator, and the other branch is connected to a gas-liquid separator. The centrifugal separator is divided into two branches, one branch is connected to the acid water storage tank, and the other branch is connected to the dichloroethane storage tank, so that the reaction selectivity of the anthraquinone nitration reaction can be effectively improved, high-viscosity solids are prevented from being blocked, and the conversion rate of raw materials in the continuous reaction of the anthraquinone nitration reaction is improved.

The subject of the invention is N-substituted derivatives of l-(l-phenyl-3-aryl)-lH-pyrazol-4-yl)methanamine with the general formula 1, where ¥ represents CH or N, R1 represents hydrogen, R2 represents no substituent, R3 represents hydrogen, while R4 represents N-propylbenzamide, benzo[b]furan, dihydrobenzo [b] furan, methylenedioxybenzene, ethyl benzoate, or propyl benzoate, substituted accordingly, their method of production and application, and the method of obtaining and application of N-substituted derivatives of l-(l-phenyl-3-aryl)-IH-pyrazol-4-yl)methanamine with the general formula 1, where Y represents C, CH, or N, R1 represents hydrogen or a methyl group, R2 represents a methyl group or no substituent, R3 represents hydrogen or a methyl group, while R4 represents dimethylpyrazole, methylpyrazole, dimethylimidazo[l,2-a]pyrimidine, or isopropoxybenzene, substituted accordingly. The compounds that are the subject of the invention are obtained through reductive amination using borohydride derivatives as the reducing agent, advantageously sodium triacetoxyborohydride, in the amount of 1.4-2.0 eq, amine in the amount of 1.0-1.1 eq, advantageously in slight excess, base, advantageously triethylamine in the amount of 1.0-1.1 eq (in the case of using amine in the form of hydrochloride), and the starting aldehyde. The reaction is conducted in a nonpolar solvent environment, advantageously dichloroethane at a concentration of about 0.1 M. The crude product is purified by column chromatography on silica gel using a methanol in dichloromethane mixture as the eluent, in concentration ranges from 2% to 5%. In order to obtain a solid form and improve the physicochemical parameters, the free bases are converted into hydrochloride form, and then crystallized from a polar solvent, advantageously ethanol or propanol.

A macroporous cation exchange resin and its preparation and application method are disclosed. The method involves dispersing polystyrene-divinylbenzene microspheres in dichloroethane to obtain a microsphere suspension. A sulfonating agent, a mixture of fuming sulfuric acid and chlorosulfonic acid, is then slowly added dropwise under cooling and stirring conditions. After the addition is complete, heating is initiated to trigger a polysulfonation reaction. Once the reaction is complete, the reaction mixture is slowly poured into ice water and continuously stirred and diluted until the solution pH reaches 2.5. The solution is then filtered, washed, and dried to obtain a solid resin. This invention simultaneously introduces a matched number of sulfonic acid groups and sulfone groups onto the polystyrene-divinylbenzene backbone. Utilizing the electron-withdrawing effect of the sulfone groups and the rigid framework they form, the stability of the C-H and C-S bonds in the resin is enhanced. This solves the problems of resin structure damage, rapid decline in separation performance, and significantly shortened service life associated with existing cation exchange resins used in treating chromium plating aging solutions.

The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of an isoxazoline compound. The preparation method comprises the following steps: dissolving a compound 1 and ethyl acrylate in dichloroethane, then adding tert-butyl nitrite, alkali and K2S2O8, in an air environment, irradiating with a 35 W blue LED light source and stirring at room temperature for 12 hours, after the reaction is completed, reducing pressure to remove a solvent, and then performing silica gel column chromatography on a crude product to obtain a product, namely the isoxazoline compound. The synthesis method provided by the invention avoids the problem of residue of a traditional metal catalyst, and provides a new normal form for green synthesis of the isoxazoline compound. As a key intermediate, isoxazoline can derive beta-lactam, beta-amino alcohol and other structures, and a new path is provided for complex molecule synthesis.

The application discloses a preparation method of 1-(2-aminoethyl) pyrrolidine and belongs to the field of chemical synthesis. The application provides a novel synthesis method of 1-(2-aminoethyl) pyrrolidine, which is prepared from 1,2-dichloroethane and pyrrolidine as raw materials, addition of a solvent and alkali, heating reaction, extraction, acidification and reduced-pressure distillation after the reaction is finished to obtain N-(2-chloroethyl) pyrrolidine solution; N-(2-chloroethyl) pyrrolidine and ammonia water are used as raw materials, high-pressure heating reaction is carried out, extraction and reduced-pressure distillation are carried out after the reaction is finished to generate 1-(2-aminoethyl) pyrrolidine. The application has the advantages of simple operation process, green process synthesis, convenient product purification and high product purity.

The invention discloses a method for preparing vinyl chloride by electrocatalytic dechlorination of 1, 2-dichloroethane, a working electrode of the method takes a metal oxide as a catalyst, and the metal oxide is selected from at least one of the following metal oxides: Pd, Mn, Fe, Co, Ni, Cu, Ru and Mo. According to the invention, the metal oxide powder is used as the electrocatalyst, the catalyst is coated on the electrode material to prepare the working electrode, the working electrode is applied to electrocatalytic dechlorination reaction of 1, 2-dichloroethane, vinyl chloride can be generated at high selectivity at room temperature, a new way is opened up for production of vinyl chloride by electrocatalytic dechlorination, and the method has wide application prospect. And a green and low-cost solution is provided for efficient synthesis of vinyl chloride.

The invention discloses amido-modified hypercrosslinked resin, a preparation method thereof and application of the amido-modified hypercrosslinked resin to adsorption of chlorine-containing VOCs (Volatile Organic Compounds). The preparation method comprises the following steps: chloromethylation: swelling hypercrosslinked NDA-88 resin in 1, 2-dichloroethane, adding anhydrous FeCl3 as a catalyst, and carrying out chloromethylation reaction at 35-40 DEG C to obtain chloromethylated resin; and amination: mixing the chloromethylated resin with an amination reagent diethylenetriamine, carrying out amination reaction at 140-150 DEG C, and carrying out post-treatment to obtain the amino modified hypercrosslinked resin. The amino-modified hypercrosslinked resin has high adsorption capacity and long penetration time for chlorine-containing VOCs (Volatile Organic Compounds) such as dichloromethane, chlorobenzene and the like, is stable in performance under the relative humidity of 50%, and is small in adsorption performance attenuation after multiple times of thermal regeneration. The resin is simple in preparation method, excellent in performance and suitable for efficient purification treatment of industrial chlorine-containing VOCs waste gas.

The invention discloses a method for preparing p-trifluoromethoxyphenol by adopting a micro-channel reactor, and belongs to the field of fine chemical engineering. 4-trifluoromethoxyaniline and dilute sulphuric acid are pumped into the first micro-channel reactor for a reaction; then introducing inert gas, pumping the nitroso sulfuric acid solution, and carrying out diazotization reaction to obtain a diazonium salt solution; pumping the diazonium salt solution into a second micro-channel reactor, carrying out hydrolysis reaction, adding dichloroethane extract liquor into a rectifying tower after the reaction is ended, and rectifying to obtain p-trifluoromethoxyphenol; porous baffles which are inclined downwards are arranged on the inner wall of the rectifying tower in a crossed manner; a heat-conducting filler layer of 50-100 nm is arranged on the porous baffle plate; the heat-conducting filler layer is a three-dimensional net-shaped material layer which is formed by boron nitride nanosheets / titanium oxide nanorods and has a porous structure. The method is simple in process route, convenient to operate, high in controllability, high in safety, high in reaction efficiency, high in product yield, capable of effectively reducing the solid waste amount in production, energy-saving, environment-friendly and suitable for industrial production.

The invention discloses a method for synthesizing 2-aminopyridine, comprising using polystyrene resin beads as a carrier, a mixed solvent consisting of 1,2-dichloroethane and anhydrous ethanol as a porogen, adding the polystyrene resin beads and the mixed solvent to a flask for swelling; adding N,N-dimethylaniline to the flask, and performing a stirring reflux reaction; repeatedly washing the mixed solution in the flask with anhydrous ethanol and filtering it with suction, and finally vacuum drying it at room temperature. The method for synthesizing 2-aminopyridine utilizes polymer resin beads as a carrier, grafts a preferred highly active phase transfer catalyst molecule - N,N-dimethylaniline, and synthesizes a solid-supported phase transfer catalyst to achieve efficient recycling and regeneration of the phase transfer catalyst, and ensures the yield of the pyridine amination product by the solid-supported phase transfer catalyst, which is conducive to ensuring the efficient resource utilization of basic nitrogen heterocyclic compounds in coal tar.

This invention discloses a highly selective method for preparing triethylenetetramine. The method uses 2-chloroethylamine hydrochloride and ethylenediamine as raw materials, reacting them in an aqueous solution. An aqueous solution of ethylenediamine with a concentration of 1-100 wt% is added dropwise to an aqueous solution of 2-chloroethylamine hydrochloride with a concentration of 1-100 wt%. The dropping rate of the ethylenediamine solution is 5% to 100% of its own mass per hour. The reaction temperature is 30-200 °C (oil bath temperature), and the reaction time is 2-20 hours (including the dropping time). The molar ratio of 2-chloroethylamine hydrochloride to ethylenediamine is 2:1 to 40:1. This invention is the first to propose a direct synthesis of triethylenetetramine from the bulk chemicals 2-chloroethylamine hydrochloride and ethylenediamine. Compared with the previously reported dichloroethane amination method and the nucleophilic substitution method between dichloroethane and ethylenediamine, this method offers milder reaction conditions, simpler operation, and higher selectivity, making it suitable for industrial production.

The invention belongs to the technical field of polysulfide sealants, and relates to a bi-component modified polysulfide sealant for a binding surface as well as a preparation method and application of the bi-component modified polysulfide sealant. The bi-component modified polysulfide sealant for the binding surface is prepared from a component A and a component B according to the mass ratio of 100: (8-12), the component A comprises modified polysulfide rubber, a functional filler, a coupling agent, an adhesive and a regulator; the modified polysulfide rubber is prepared from polysulfide rubber and a modifier; the modifying agent is one of bis (2-chloroethyl) ether, 1, 2-dichloroethane and bis (chloromethyl) dimethylsilane; and the component B comprises a metal oxide, a plasticizer, an accelerant and a regulator. According to the modified polysulfide sealant formed by two components, the elongation at break of the polysulfide sealant is improved in an extreme environment, the sealant has excellent deformation resistance, cracking, shrinkage and bonding failure of a sealant layer are avoided, and the sealing performance of a binding surface is improved.

The utility model relates to the technical field of synthetic reaction devices of 2, 6-difluorobenzamide, in particular to a synthetic reaction device of 2, 6-difluorobenzamide, which comprises a stirring mechanism, the stirring mechanism comprises a supporting frame, a fixed bearing is fixedly arranged at the bottom end of the supporting frame, a stirring rod is fixedly arranged at the bottom end of the fixed bearing, a metal fixing sleeve is fixedly arranged on one side of the stirring rod, and a stirring paddle is fixedly arranged on one side of the metal fixing sleeve. And a supporting rotating platform is fixedly arranged at the bottom end of the stirring rod. Production materials are fed into the reaction kettle mechanism through the convenient feeding nozzle, then the stirring paddle is started by controlling the electric driving mechanism, and the stirring rod is controlled by the driving motor to rotate, so that the stirring paddle on one side of the stirring rod is driven to rotate and stir, the mixing of the coating is promoted, and the mixed 2, 4-dichloroethane is added into the reaction kettle mechanism. And 2, 6-difluorobenzamide is discharged through a discharge valve at the bottom of the reaction kettle mechanism and is conveyed to the next process.

The present application relates to the field of chemical synthesis, in particular to a synthesis method of N-oxobutane acetamide and derivatives thereof.The synthesis method comprises the following steps: reacting a phenone compound with a nitrile compound, an acid and a reaction solvent to obtain the N-oxobutane acetamide and derivatives thereof; the phenone compound is p-bromophenone, p-fluorophenone, p-chlorophenone, p-iodophenone, p-cyanophenone, 3,4-dimethylphenone or 2-naphthaldehyde; the nitrile compound is acetonitrile, 3-chloropropionitrile, dichloroacetonitrile or deuterated acetonitrile; the acid is CF3SO3H or BF3; and the reaction solvent is acetonitrile or dichloroethane.The present application directly constructs the N-oxobutane acetamide and derivatives thereof in one step with the nitrile compound as the only nitrogen source, and has the advantages of cheap and easily available raw materials, mild conditions, high yield and easy scale-up production.

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 1-benzyl alcohol-3-alkyl bicyclo [1.1. 1] pentane, which comprises the following steps: by taking aromatic aldehyde, [1.1. 1] propeller alkane and 4-alkyl substituted Hanss ester synthesized by aldehyde as initial raw materials and dichloroethane and the like as a solvent, carrying out a reaction under the protection of inert gas to obtain 1-benzyl alcohol-3-alkyl bicyclo [1.1. 1] pentane, and separating the 1-benzyl alcohol-3-alkyl bicyclo [1.1. 1] pentane from the 1-benzyl alcohol-3-alkyl bicyclo [1.1. 1] pentane. A three-component free radical coupling reaction is carried out under the illumination condition, and a 1-benzyl alcohol-3-alkyl bicyclo [1.1. 1] pentane product is synthesized in one step. The method has the advantages of mild reaction conditions, high reaction efficiency, low cost, simplicity and convenience in operation and the like, and a new method is provided for later structural modification of diaryl methanol drug molecules.

The invention discloses a high-boiling-point styryl liquid cross-linking agent, a preparation method thereof and organic medium slurry of a high-frequency and high-speed copper-clad plate. The preparation method of the high-boiling-point styryl liquid cross-linking agent comprises the following steps: carrying out Friedel-Crafts reaction on toluene and dichloroethane to obtain 1, 2-bis (methyl benzene) ethane; the preparation method comprises the following steps: carrying out Friedel-Crafts reaction on dimethyl phenylethane and acetyl chloride to obtain 1, 2-bis (methyl acetyl benzene) ethane; the preparation method comprises the following steps: carrying out reduction reaction on 1, 2-bis (methyl acetyl benzene) ethane and sodium borohydride to obtain 1, 2-bis (methyl alpha hydroxyethyl benzene) ethane; and carrying out dehydration to obtain the 1, 2-bis (methyl vinyl benzene) ethane cross-linking agent. The 1, 2-bis (methyl vinyl benzene) ethane is in a liquid state at normal temperature, has high solubility for SEBS and other film-forming resins, can reduce the solvent amount for copper-clad plate manufacturing, is a high-boiling-point cross-linking agent, and has wide application prospects.

The invention discloses a preparation method of tris (2-cyanoethyl) phosphate, which comprises the following steps of: 1, adding 3-hydroxypropionitrile, an organic alkali acid-binding agent and a reaction organic solvent which is one of dichloromethane and dichloroethane into a reaction container, and reacting at the temperature of between 20 and 30 DEG C for 1 to 3 hours; controlling the temperature not to exceed 20 DEG C, dropwise adding a mixture formed by phosphorus trichloride and a reaction organic solvent, after dropwise adding is completed, performing heating reflux reaction, and after the reaction is completed, performing suction filtration to remove generated organic alkali hydrochloride so as to obtain filtrate; and 2, controlling the temperature of the filtrate obtained in the step 1 at 30-40 DEG C, introducing oxygen for reaction until the reaction is finished, and removing the reaction organic solvent to obtain the final product tris (2-cyanoethyl) phosphate. The method has the advantages of simplicity in operation, mild and controllable reaction, high product purity and suitability for industrial popularization.

The utility model provides a kettle for dehydration and alcohol removal of dichloroethane, which comprises a reaction kettle, the reaction kettle comprises a kettle body, a stirring mechanism is fixedly arranged at the top of the kettle body, a stirring shaft is fixedly connected with a transmission mechanism through a support rod, the bottom of the transmission mechanism is fixedly connected with a mixing mechanism, the mixing mechanism comprises a connecting seat, a stirring rod and a hydraulic cylinder, the connecting seat is fixedly connected with the bottom of the enclosure, the top end of the stirring rod is rotatably connected with the interior of the connecting seat, and a plurality of uniformly distributed rod bodies are arranged on the stirring rod. The stirring mechanism and the mixing mechanism are arranged in the kettle body and are matched to realize full mixing, and the mixing mechanism can be folded after stirring, so that the mixing efficiency can be improved, the subsequent standing layering cannot be influenced, the production period of dichloroethane can be effectively shortened, the production efficiency is improved, and the production cost is reduced. The dichloroethane recovery solvent is subjected to washing alcohol removal treatment, and the yield of acylation reaction is better stabilized and improved, so that the solvent scrap consumption and the production cost are reduced.

The invention relates to a device and a method for producing partially chlorinated alkanes by means of a direct chlorination of alkenes. In particular, the invention relates to a device and a method for producing 1,2-dichloroethane by means of a direct chlorination of ethene (synonym: ethylene). The invention is characterized in that a loop reactor is used for the direct chlorination, wherein the outlet for the produced partially chlorinated alkane is provided on a vertical position of the loop reactor (in the operating state) on a lateral wall of the loop reactor, the vertical position being situated below half the height of the loop reactor.

This invention discloses a method for preparing a metal carbide catalyst for dichloroethane cracking. Specifically, an anion exchange resin is first subjected to simultaneous ion exchange with silicate and metal-containing anions, followed by pyrolysis at high temperature to obtain a composite material of metal carbide and silica. Subsequently, the silica portion of the composite material is removed, resulting in a metal carbide catalyst with a high specific surface area. This preparation method is simple, and the obtained catalyst has a large specific surface area and high strength, showing broad application prospects in the dichloroethane cracking reaction.

The application provides a synthesis method of 9,10-dibromoanthracene, by introducing HBr generated by a solvent water adsorption reaction, using an industrial sodium hypochlorite solution to react the HBr into bromine, ensuring high concentration of bromine, introducing a solvent dichloroethane to uniformly disperse raw materials, keeping the concentration of bromine stable in the reaction, greatly promoting the reaction speed, greatly shortening the reaction time, and converting the sodium hypochlorite into a sodium chloride aqueous solution after the reaction is completed. The purity of the prepared 9,10-dibromoanthracene is more than 99%, and the by-products generated in the reaction are environment-friendly and non-polluting.

The application belongs to the technical field of ion detection, and particularly relates to a preparation method of a rapid detection uranyl ion ratio type fluorescent probe, comprising the following steps: dissolving rhodamine B and phosphorus oxychloride in 1,2-dichloroethane to obtain product 1; dissolving the product 1 in acetonitrile, adding 2-aminobenzimidazole and triethylamine, and stirring under heating; after the reaction is completed, column chromatography purification is carried out, and vacuum drying is carried out to obtain the target product fluorescent probe RBN; and the fluorescent probe RBN is dissolved in DMSO to prepare a mother liquor. The fluorescent probe has the advantages of rapid response to uranyl ions, simple synthesis route, simple detection equipment and method, and the like, and can be used for qualitative and quantitative detection of uranyl ions in an environment and a biological system.

The invention discloses a preparation method and a preparation system of p-chloro-o-cresol, and the preparation method comprises the following steps: 1) adding dichloroethane into molten o-cresol, and adding a catalyst; (2) controlling the temperature to be 5-15 DEG C, and adding sulfuryl chloride into the material in the step (1) at different feeding speeds according to the reaction time and the reaction stage; and (3) after the reaction is finished, rectifying and purifying liquid of reaction materials to obtain the p-chloro-o-cresol. According to the present invention, the process is simple, the reaction condition is mild, the reaction is controlled, the selectivity is high, the ortho-cresol is subjected to preferential para-position chlorination, the reaction is sufficient, the selectivity is high, the polychlorination phenomenon is avoided, the phenol content and the isomer content in the crude product are low, the yield is high, and the large-scale production is easily achieved.

The application discloses a preparation method and application of a catalyst for cracking 1,2-dichloroethane to produce vinyl chloride, and comprises the following steps: 1) a neodymium ore is leached with hydrochloric acid, and after filtering a leaching solution, potassium chloride is added to form a doped precursor K2[NdCl3]; 2) an active metal oxide is dissolved in hydrochloric acid, and then added into the doped precursor K2[NdCl3] solution, and co-precipitation is carried out by adding alkali to obtain an emulsion of a doped active component; the active metal oxide is at least one of oxides of vanadium, manganese, titanium and scandium; 3) the emulsion of the doped active component is mixed with a liquid carrier to obtain the catalyst; the liquid carrier is one or more of chloroform, carbon tetrachloride, 1,1,2-trichloroethane and chlorobenzene.

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 synthesis, and discloses a preparation method for trifluoromethylation of a 1, 6-enyne substrate. The preparation method comprises the following steps: in a protective gas atmosphere, mixing a 1, 6-eneyne substrate, NaSO2CF3, an oxidant, N-bromosuccinimide and an organic solvent, heating to react, cooling, separating an organic phase, drying and purifying to obtain a product after trifluoromethylation of the 1, 6-eneyne substrate, the organic solvent is selected from any one of dimethoxyethane and 1, 2-dichloroethane. The preparation method is mild in reaction condition, simple and convenient to operate, good in substrate applicability, good in substrate selectivity in reaction and high in target product yield, and a new way is provided for trifluoromethylation of the 1, 6-eneyne compound.