687 results about "Nitrobenzene" patented technology

The invention discloses a preparation method of second-generation denitrified flavin TND1128, which comprises the following steps: S1, by taking 1-methylbarbituric acid and o-aminobenzaldehyde as raw materials and a mixture of water and alcohol as a solvent, heating and reacting to generate an intermediate I; s2, taking the intermediate I as a raw material, and performing ethylation under the combined action of inorganic alkali and an ethylation reagent to generate a TND1128 crude product; s3, the TND1128 crude product is purified, and a TND1128 pure product is obtained; according to the invention, 1-methylbarbituric acid and 2-nitrobenzaldehyde are taken as raw materials for cyclization synthesis of an intermediate I, then ethylation and pulping purification are carried out under the combined action of inorganic base and an ethylation reagent, and high-purity TND1128 is synthesized in a high-yield, high-specificity and high-selectivity manner; the method has the advantages of simple process route, good reaction selectivity, high yield, cheap and easily available raw materials, low equipment requirement, easy realization of industrial production and the like.

The invention discloses a method for reducing nitro compounds through an electrochemical microreactor. According to the method, nitrobenzene or a derivative thereof is subjected to electrochemical catalysis in a multi-channel series electrolytic tank in a constant-current electrolysis mode to be reduced to generate aniline or a corresponding aniline derivative. According to the method disclosed by the invention, the Faraday efficiency is improved from 40% to more than 80% under the condition that the yield of the nitrobenzene is kept unchanged compared with that of the existing electrochemical reduction nitrobenzene, so that the fixed energy consumption is greatly reduced, and rapid, efficient, continuous and large-scale production of the nitrobenzene and the derivatives thereof is realized.

The invention discloses a synthesis method of 2, 4, 5-trifluorophenylacetic acid, which comprises the following steps: by taking cheap and easily available o-chloronitrobenzene as a raw material, reacting with sodium nitrate in a sulfuric acid and trifluoroacetic acid system, separating generated 2, 4-dinitrochlorobenzene through melt crystallization, and continuing to synthesize 2, 4-dinitrochlorobenzene in methyl chloroacetate to obtain 2, 4, 5-trifluorophenylacetic acid. The method comprises the following steps: carrying out indirect aromatic nucleophilic substitution reaction on 2, 4-dinitrophenylacetic acid under the condition of sodium hydride to generate 5-chloro-2, 4-dinitrophenylacetic acid methyl ester, separating, carrying out fluorination reaction on the 5-chloro-2, 4-dinitrophenylacetic acid methyl ester and potassium fluoride under the action of a phase transfer catalyst, carrying out rectification separation to obtain 2, 4, 5-trifluorophenylacetic acid, and carrying out hydrolytic acidification on the 2, 4, 5-trifluorophenylacetic acid in a sodium hydroxide aqueous solution to obtain 2, 4, 5-trifluorophenylacetic acid. And the process route is safer, more environment-friendly, more efficient and lower in cost.

The invention discloses a C2 spiro indolone compound as well as a preparation method and application thereof, simple and easily available N-indole connected o-alkynyl nitrobenzene compound is used as a raw material, and the C2 spiro indolone compound is obtained by heating reaction in a solvent under the catalysis of a cheap metal copper catalyst. The C2 spiro indolone compound prepared by the invention has a relatively good inhibition effect on phytopathogen, and can be used for preventing and treating botrytis cinerea, sclerotinia rot of colza and botryosphaeria dothidea; the preparation method does not need to use an expensive metal catalyst, does not need an additional reducing agent, and has the advantages of simple operation, high chemical selectivity, wide reaction substrate range and the like.

The invention relates to a polycarboxylic acid water reducer and a preparation method thereof, and the water reducer is prepared from the following raw materials: 45 to 55 percent of isopentenyl polyoxyethylene ether, 28 to 35 percent of acrylic acid, 1.5 to 2.5 percent of modifier, 0.3 to 0.5 percent of ammonium persulfate, 0.03 to 0.06 percent of ascorbic acid, 5 to 8 percent of hydroxyethyl methylacrylate, 0.15 to 0.25 percent of 2, 4-diphenyl-4-methyl-1-pentene and the balance of water. The modifier is prepared from the following raw materials: 1, 5-dichloronaphthalene, p-nitrostyrene, dimethyl sulfate, ceric ammonium nitrate and tetramethylpiperidine oxide. The polycarboxylate superplasticizer has excellent neat paste fluidity and fluidity retention capability, has low 1h time-dependent variable slump which is below 18mm and optimally 10mm when applied to concrete, has a water-reducing rate of more than 40% and a gas content of less than 3.8%, and also has more advantages in compressive strength ratio.

The invention relates to the technical field of preparation of N-(2, 4-dinitrophenyl)-4-nitrobenzoyl aniline, in particular to a method for preparing a nitro amide compound by adopting a microreactor. The method for preparing the nitro amide compound comprises the following steps: introducing a sulfuric acid solution of 4-nitro-N-phenylbenzamide and a nitric acid aqueous solution into a microreactor, and reacting to obtain N-(2, 4-dinitrophenyl)-4-nitrobenzamide; the microreactor is provided with at least two reaction modules which are connected in series, and a sulfuric acid solution of 4-nitro-N-phenylbenzamide is divided into at least two strands which are respectively fed into a first reaction module of the microreactor and other reaction modules except the first reaction module; and the nitric acid aqueous solution enters the microreactor in a way of at least one stream. According to the method, the microreactor is used as a reaction carrier, the temperature in the reaction process is controllable, the raw material conversion rate is increased, and the residual amount of an intermediate N-4-nitro-(4-nitrophenyl) benzamide is reduced.

The invention relates to the technical field of synthesis of organic compounds, and discloses a synthesis method of an o-aminoanisole compound, which comprises the following steps: preparing a composite alkali slow-release system consisting of inorganic alkali and organic alkali; preparing a catalytic reduction reaction system containing a metal complex stabilizer, a transition metal catalyst and a hydrophilic ether cosolvent; a catalytic reduction reaction of o-nitroanisole is carried out, and the slow-release alkali-coated material gradually releases the composite alkali to maintain a stable pH environment; after the reaction is completed, adding a packing material rapid digesting agent to remove a packing material structure, and meanwhile, rapidly separating and protecting a product by using a product protective extracting agent and an antioxidant synergistic protective agent; and purifying and recovering the final product to obtain a high-purity o-aminoanisole product. The reaction efficiency, the product purity, the service life of the catalyst and the separation efficiency are comprehensively improved through the synergistic effect of the eight components, the product purity reaches 99.5% or above, the catalyst can be recycled for 5-8 batches, and the separation time is shortened to 0.5-1 hour.

The invention belongs to the technical field of catalysts, and particularly relates to a formaldehyde removal catalyst and a preparation method and application thereof. The formaldehyde removal catalyst is prepared by carrying out hydrothermal reaction and roasting treatment on a mixture of the following raw materials: metal salts including Mn salt, Co salt and Fe salt; an organic precursor, wherein the organic precursor comprises 2-nitroaniline and carboxymethyl cellulose; wherein the molar ratio of the Mn element to the Co element to the Fe element in the metal salt is (4.5 to 5.0): (2.0 to 2.5): (1.5 to 1.8); the ratio of the total mass of the Mn element, the Co element and the Fe element in the metal salt to the mass of the organic precursor is (80-85): (15-20). According to the formaldehyde removal catalyst, the metal elements are loaded on the hydrophobic carbon layer of the nitrogen-containing structure, so that the problem that the toluene adsorption capacity is weak due to the fact that a traditional catalyst does not have specific sites is solved, and the problem that the catalyst is inactivated due to the fact that multiple pollutants compete for active sites and a product overflows slowly can also be solved.

The invention relates to a suzertraline intermediate as well as a preparation method and application thereof, and particularly provides a suzertraline intermediate 3, 4-difluoro-2-methoxyphenylacetic acid compound and a preparation method thereof, and the suzertraline intermediate can be used for preparing 3, 4-difluoro-2-methoxyphenylacetic acid. Specifically, 2, 3, 4-trifluoronitrobenzene which is low in price and easy to obtain serves as a starting raw material, 3, 4-difluoro-2-methoxyphenylacetic acid is prepared through a substitution reaction, a methylation reaction, a reduction reaction, a Meerwein arylation reaction and a hydrolysis reaction, the method is mild in reaction condition, a reaction substrate better meets the economic and environment-friendly requirements, reaction operation and a post-treatment process are safe and simple, and the method is suitable for industrial production. The purification steps are simple and convenient, byproducts are few, a target product with high purity can be obtained conveniently, corrosion to equipment is small, special equipment is not needed, and the method is suitable for industrial production.

The application provides a method for continuously preparing nitrobenzene by using benzene and NO2 as raw materials. The method is characterized in that: a solid catalyst capable of catalyzing the nitration of benzene by NO2 is filled in a pipe reactor, benzene, NO2 and O2 are continuously fed into the pipe reactor at a certain flow rate, and the reaction is carried out at a certain temperature to obtain nitrobenzene. This route is safe, green, economical and efficient, and is a safe, green, economical and efficient nitrobenzene synthesis route.

The invention relates to a diyne functionalized covalent organic framework material as well as a preparation method and application thereof, and the diyne functionalized covalent organic framework material is synthesized by taking 4, 4 ', 4', 4 ''-(pyrene-1, 3, 6, 8-tetrayl) tetraphenylamine and 5, 5 '-(butyl-1, 3-diyne-1, 4-diyl) diisophthalaldehyde as construction units and adopting a Schiff base reaction. The dialkynyl functionalized covalent organic framework material disclosed by the invention has good chemical stability and can be used as a carrier to controllably grow silver nanoparticles through metal coordination to obtain a composite material, and the composite material shows excellent catalytic activity and cycling stability in a 4-nitrophenol reduction reaction catalyzed by sodium borohydride; therefore, the method has important application potential in the fields of environmental restoration, green chemistry and the like.

The application discloses a misaligned ten-membered cucurbituril-based assembly and application thereof in detecting and removing trinitrophenol. The assembly is assembled by using misaligned ten-membered cucurbituril and 8-hydroxyquinoline as raw materials. The misaligned ten-membered cucurbituril-based assembly is a novel supramolecular assembly, can be used for fluorescent identification of trinitrophenol in an aqueous solution, and has the characteristics of simple detection instrument, high selectivity, good sensitivity, wide detection range, fast response time, and the like. In addition, the misaligned ten-membered cucurbituril-based assembly has the characteristic of being capable of removing trinitrophenol in the aqueous solution.

The application discloses a preparation method of fenbendazole impurity C, wherein the fenbendazole impurity C is impurity C in the European Pharmacopoeia (EP), and the compound has a molecular formula of C 27 H 23 N5O2S2, the application takes 2-nitro-5-phenylmercaptoaniline as raw material, realizes the preparation of the fenbendazole impurity C through a four-step reaction in the following route, the preparation method of the impurity compound is easy to obtain raw materials, simple to operate, reasonable in process design, relatively mild in reaction condition, high in yield, and can realize industrial production, the prepared fenbendazole impurity C can be used as a control sample for qualitative and quantitative research of impurity C in fenbendazole quality research, the content of the fenbendazole impurity C is controlled, so that the quality of the crude drug is ensured.

The present invention proposes a method and use for stabilizing a simple agglomerate for pH and salt and with adjustable size. In phosphoric acid buffer solutions with different salt concentrations and pH values, the polyacrylic acid hydroxypropyl group condensation body has specific stability; hydrophobic thermal response blocks are introduced into a hydroxypropyl acrylate monomer through reversible addition-fragmentation chain transfer polymerization to regulate and control the size of a condensation body, and a phase separation behavior is shown at different temperatures; a hydrophobic block without thermal response is introduced to regulate and control the size of the aggregate, and no thermal response behavior is shown. Continuous regulation and control of the size of the aggregate from the micron level to the nano level are achieved, and the requirements of different application scenes are met. The hydroxypropyl polyacrylate condensation body can be used for packaging various dyes and drugs; high-efficiency enzyme protection is achieved, formed aggregates can protect glucose oxidase, and the retention rate of enzyme activity reaches 85% or above after treatment is conducted for 3 hours at 60 DEG C; as a micro-reactor for the reaction of generating p-nitrobenzaldehyde phenylhydrazone from p-nitrobenzaldehyde and phenylhydrazine, the reaction rate is greatly improved.

This invention discloses a method for preparing and analyzing trans-4-aminocyclohexylacetic acid. The preparation method is as follows: 4-nitrophenylacetic acid undergoes catalytic hydrogenation in a solvent, followed by filtration. The filtrate is then treated with acid to obtain a 4-aminophenylacetic acid salt solution. The collected catalyst is activated. The 4-aminophenylacetic acid salt solution is mixed with isopropanol, barium hydroxide, tetrabutylammonium bromide, 18-crown ether-6, and dibutyl phthalate. The activated catalyst is then added to initiate a catalytic hydrogenation reaction. After the reaction, the reaction solution is cooled and filtered. The resulting solid is mixed with a preheated dilute sulfuric acid solution and stirred to form a slurry. The mixture is then filtered, and the filtrate is neutralized and filtered again. The collected filtrate is concentrated and crystallized. The crystallized precipitate is washed and dried to obtain trans-4-aminocyclohexylacetic acid. The method provided by this invention has high reaction efficiency, mild conditions, and is suitable for industrial production. It yields high product purity and reliability. Furthermore, the analytical method provided by this invention is accurate and reliable.

The invention discloses a synthesis method of 5-(1H-pyrrole-1-yl)-2-mercaptobenzimidazole, which comprises the following steps: carrying out cyclization condensation reaction on o-phenylenediamine and thiourea in an acidic environment provided by hydrochloric acid to obtain 2-mercaptobenzimidazole; the preparation method comprises the following steps: carrying out nitration reaction on 2-mercaptobenzimidazole, sulfuric acid and nitric acid to obtain 2-mercapto-5-nitrobenzimidazole; the preparation method comprises the following steps: carrying out nitro reduction reaction on 2-sulfydryl-5-nitrobenzimidazole and hydrogen under the catalysis of nickel to obtain 5-amino-2-sulfydryl benzimidazole; the preparation method comprises the following steps: carrying out an N-alkylation reaction on 5-amino-2-mercapto benzimidazole and tetrahydro-2, 5-dimethoxyfuran under the catalysis of copper chloride to generate 5-(1H-pyrrole-1-yl)-2-mercapto benzimidazole, and carrying out a reaction on the 5-amino-2-mercapto benzimidazole and tetrahydro-2, 5-dimethoxyfuran to generate the 5-(1H-pyrrole-1-yl)-2-mercapto benzimidazole. The method disclosed by the invention has the outstanding advantages of mild and easily-controlled conditions, simple and convenient post-treatment, high yield, economy, environmental protection, suitability for large-scale production and the like, conforms to the green chemical development concept, and has important application value.

This invention relates to a method for preparing and applying polyamides from a monomer containing 7-methyldibenzo[c,g]carbazole and triphenylamine: 4-({9-[(4-aminophenyl)(4-methoxyphenyl)amino]-7-methyldibenzo[c,g]carbazole-5-yl}(4-methoxyphenyl)amino)aniline. To address the problems of low solubility, difficulty in film formation, poor cycling stability, narrow color change range, and limited functionality in polyamide materials, this invention constructs two triphenylamine groups on 7-methyldibenzo[c,g]carbazole and introduces a methoxy group onto the triphenylamine to increase the polymer's solubility and stability. The polymer of this invention exhibits excellent electrochromic properties, including excellent cycling stability, fast switching time, and high optical contrast. Furthermore, to address the material's multifunctionality, a naphthalene unit is added to the molecular structure, resulting in a polymer with fluorescent emission. This invention can be applied to displays, rearview mirrors, camouflage applications, and the fluorescence detection of p-trinitrophenol.

The invention relates to a process for producing nitrobenzene by an adiabatic nitration of benzene (2) and nitric acid (1) in the presence of sulfuric acid (7), the process comprising: (a) feeding benzene (2), nitric acid (1) and sulfuric acid (7) into a reaction zone (R); (b) producing a reaction mixture (4) comprising water, nitrobenzene and sulfuric acid by reaction of the benzene and the nitric acid in the presence of the sulfuric acid in the reaction zone (R); and (c) separating the reaction mixture into an aqueous phase (6) comprising water and sulfuric acid and an organic phase (5) comprising crude nitrobenzene by phase separation; wherein the concentration of titanium in the reaction mixture (4) is kept below 170 mg / kg.

The invention discloses a synthesis method of 5-nitro-2-aminophenol, which comprises the following steps: by using 2-chloro-4-nitroaniline as a raw material, providing an amino protecting group by using di-tert-butyl dicarbonate ester to obtain a compound 3; carrying out hydrolysis reaction in an alkaline environment to hydrolyze chlorine groups on benzene rings into hydroxyl groups to obtain a compound 4; and removing an amino protecting group under an acidic condition to obtain the 5-nitro-2-aminophenol. According to the method, 2-chloro-4-nitroaniline is used as a starting raw material, compared with expensive ortho-aminophenol, the cost of the raw material can be remarkably reduced, use of expensive catalysts in the hydrolysis process is avoided through amino protection, generation of the byproduct 2-amino-4-nitrophenol is effectively reduced, and the yield of the 2-chloro-4-nitrophenol is increased. And the synthesized 5-nitro-2-aminophenol has relatively high purity (99.5%) and relatively high yield (-86%). The method has the advantages of conventional production steps and conventional process equipment, and has a good application prospect.

The invention discloses an application of a copper nano-cluster with stable ascorbic acid in detection of p-nitrophenol, the copper nano-cluster with stable ascorbic acid is used as a fluorescent probe, and the detection of p-nitrophenol is realized through a fluorescent sensing method. Due to the quenching effect of p-NP, the fluorescence intensity of the system is obviously reduced in the presence of p-NP. The p-NP concentration can be quantitatively detected by comparing the fluorescence intensity of the copper nano-cluster and the fluorescence intensity of a quenching system. The method is simple, sensitive and high in selectivity, does not need complex fluorescent dye labeling, shows remarkable potential for p-NP detection, and has a good application prospect in the aspects of food, medicine and the like.

The present disclosure relates to crystalline forms of 2-{3-[1-(2-nitrophenyl)-1H-pyrrol-2-yl]prop-2-ene-1-pyridine}hydrazine-1-carboximidamide that have high solubility under acidic conditions. The present disclosure also relates to the use of said crystalline forms in medicine.

This invention discloses a continuous synthesis apparatus and process for nitrobenzene. The synthesis apparatus includes a mixed acid preparation system, a continuous benzene nitration system, an organic phase continuous stratification system, and a continuous water washing-alkali washing-water washing system. The process includes: concentrated sulfuric acid and concentrated nitric acid are pumped into the mixing module of the mixed acid preparation system to obtain a mixed acid solution; benzene and the mixed acid solution are pumped into the microchannel reactor of the continuous benzene nitration system; the nitrated material is cooled and then pumped into the continuous organic phase stratification system; the resulting intermediate organic phase nitrate enters the next processing unit; the organic phase nitrate and water enter the continuous water washing-alkali washing-water washing system for washing to obtain the final product, nitrobenzene. The synthesis apparatus and process of this invention achieve continuous production of nitrobenzene throughout the entire process, realizing continuous and automated operation from raw material benzene to the final product, nitrobenzene.

The application provides a preparation method of an indobufen key intermediate. The method uses 2-(4-nitrophenyl) butyric acid and phthalic anhydride as raw materials, and obtains the target compound (I) through a one-pot method. The method has the advantages of simple operation, mild conditions, high reaction yield, reduced cost through mother liquor recycling and reuse, significantly reduced "three wastes" and environmental protection, and is suitable for large-scale industrial production.

The present invention relates to the technical field of organic synthesis. Provided is a method for preparing 2,6-bis(4-azidobenzylidene)-4-methylcyclohexanone, comprising the following steps: S1, subjecting 4-nitrobenzaldehyde and trimethylsilyl azide to a nucleophilic aromatic substitution reaction to obtain 4-azidobenzaldehyde; S2, subjecting 4-azidobenzaldehyde and 4-methylcyclohexanone to an aldol condensation reaction, so as to obtain 2,6-bis(4-azidobenzylidene)-4-methylcyclohexanone. The described technical solution addresses the problems in the related art where the process for synthesizing 2,6-bis(4-azidobenzylidene)-4-methylcyclohexanone has low product yield, high costs and high energy consumption, and is not conducive to large-scale industrial production.

The application discloses a production system of o-nitrobenzenesulfonyl chloride, which comprises an etherification reaction kettle, a material transfer structure, a recrystallization pool, a separation mechanism and a chlorination reaction kettle. The material transfer structure comprises a rotary driving mechanism, a rotating disc and a charging disc. A plurality of rotating rods are fixedly connected to the rotating disc. The bottom of the charging disc is provided with a filter screen. A filtering station, a recrystallization station, a first drying station, a chlorination station, a second drying station and a discharging station are sequentially arranged around the rotating disc. The recrystallization pool is located directly below the recrystallization station. Drying boxes are respectively arranged below the first drying station and the second drying station. The chlorination reaction kettle is located directly below the chlorination station. The production system of o-nitrobenzenesulfonyl chloride realizes continuous and automatic production of o-nitrobenzenesulfonyl chloride through the arrangement of the recrystallization station and the multiple chlorination stations, guarantees the purity and yield of the product and improves the production efficiency.

The invention relates to the technical field of metal surface treatment, in particular to a high-salt-spray-corrosion-resistance workpiece surface phosphating treatment method. The method comprises the following working procedures of ultrasonic oil removal, water washing, water washing, activation, dipping phosphorization, water washing, water washing, ultrasonic hot water washing and drying, and dipping phosphorization refers to that an activated workpiece is put into a phosphating solution to be subjected to phosphating treatment; the phosphating solution comprises the following components: 5-8 g / L of organic phosphonic acid, 30-40 g / L of zinc dihydrogen phosphate, 50-55 g / L of calcium nitrate, 2-4 g / L of sodium m-nitrobenzenesulfonate, 1-2 g / L of an accelerant, 0.5-0.8 g / L of a surfactant, 1-3 g / L of sodium molybdate, 2-4 g / L of citric acid and 0.2-0.44 g / L of rare earth salt. Through low-temperature high-efficiency process design and multi-component collaborative innovation, breakthrough is achieved in the aspects of compactness, corrosion resistance, adhesive force and other core performance of the phosphating film, the environment friendliness and economical efficiency are both achieved, and a new solution is provided for metal corrosion prevention in the fields of automobiles, ships, electronics and the like.

A green synthesis method of nitrobenzene compounds, in an organic solvent, using aromatic amine as raw material, using an oxidant and a catalyst to form a reaction system, selectively oxidizing aromatic amine into corresponding nitrobenzene compounds, the method selects an oxidant which is green, pollution-free, the catalyst is common, easy to obtain, low in price, and has significant catalytic effect, and the reaction conditions are mild, simple in operation, low in cost, fast in speed, high in selectivity and high in product yield, which is a novel, good scientific research value and industrialization potential synthesis method of nitrobenzene compounds.

The invention relates to the technical field of high polymer materials, in particular to a modified asphalt coating as well as a preparation method and application thereof. The modified asphalt coating is prepared from, by weight, 40-60 parts of modified asphalt, 10-25 parts of waste rubber powder and 0.5-1 part of a rubber regeneration activating agent, the rubber regeneration activating agent is bis (2-nitrophenyl) disulfide, and the modified asphalt is nanoscale graphene or carbon nano tube modified asphalt. According to the invention, the waste rubber powder is regenerated by the specific rubber regeneration activator, and the component quality control is cooperated, so that the regeneration effect of the waste rubber powder is remarkably improved, and the mechanical properties and weather resistance of the modified asphalt coating applied to coiled material preparation are further effectively improved.

The present application relates to the technical field of biological materials, in particular to a light-responsive drug gel carrier and a preparation method thereof, in order to improve the controlled release function of the hydrogel material, the methyl methacrylate nitrobenzene compound containing nitrobenzene structure, hydantoin structure and propylene structure is prepared first, under the action of a photoinitiator, the double bond is crosslinked with methyl methacrylate and ethylene glycol methacrylate to form a hydrophilic gel network, so that the drug gel carrier is obtained; wherein the nitrobenzene structure has photosensitivity, and the crosslinking structure will be broken under ultraviolet irradiation, thereby reducing the stability of the gel material, destroying the rearrangement of the gel micelle structure, and realizing the release of the loaded drug; and the hydantoin structure introduced in the methyl methacrylate nitrobenzene compound also has good antibacterial performance, which can effectively avoid wound infection and improve wound recovery.

The application provides a regeneration method of halogenated nitrobenzene continuous hydrogenation catalyst, and relates to the technical field of fixed bed halogenated nitrobenzene hydrogenation. The regeneration method mainly comprises the following steps: using alcohol, alkali, petroleum ether and ethyl acetate to preliminarily clean the bed layer, removing azo compounds and other pollutants on the surface of the catalyst by using the special properties of ionic liquids, and then completing the regeneration of the catalyst through the steps of pickling, precious metal solution treatment and drying. The application overcomes the defects of the prior art, has the advantages of simple operation, mild conditions and low cost, realizes the in-situ removal of surface impurities such as reaction intermediates and azo compounds on the catalyst surface without damaging the structure of the catalyst and disassembling the catalyst, further supplements the lost metal active components, and can effectively restore the catalyst activity.