136 results about "Organocatalysis" patented technology

The invention relates to a preparation method of a terephthalic acid and 2-methylimidazole organic framework catalyst, and relates to a preparation method of a high polymer material catalyst, the preparation method comprises the following steps: weighing C6H4 (COOH) 2 and 2-methylimidazole, dissolving C6H4 (COOH) 2 and C4H6N2 in N, N-dimethylformamide (DMF), weighing zinc nitrate hexahydrate (Zn (NO3) 2.6 H2O), dissolving in DMF, and preparing into a solution; the preparation method comprises the following steps: mixing a C6H4 (COOH) 2 solution and a C4H6N2 solution in proportion, and uniformly stirring; slowly adding the mixed ligand solution into a mixed solution of zinc nitrate hexahydrate (Zn (NO). 6HO) dissolved in DMF (Dimethyl Formamide), and transferring into a high-pressure reaction kettle for reaction; after cooling, centrifugally separating to obtain a white solid product, washing with methanol, and drying to obtain the Zn-MOF catalyst. The Zn-MOF catalyst provided by the invention can be widely applied to polyester synthesis, esterification reaction and other organic catalytic reactions, and especially has significant advantages in PBAT synthesis.

A preparation method of 5N high-purity antimony comprises the following steps: (1) hydrolysis: taking ethylene glycol antimony as a raw material, and carrying out pyrohydrolysis pretreatment to obtain antimony trioxide; (2) biological reduction: uniformly mixing antimony trioxide with an organic catalytic reduction covering agent, and carrying out reduction smelting to prepare 4N antimony; and (3) vacuum distillation: the 4N antimony is subjected to two-stage vacuum distillation, namely first-stage high-temperature vacuum distillation and second-stage low-temperature vacuum distillation, and the 5N high-purity antimony is obtained. According to the method, an ethylene glycol antimony product is adopted as a raw material and subjected to hydrolysis-biological reduction and multi-field synergistic enhanced vacuum distillation to obtain 5N high-purity antimony, the total amount of impurity elements of the product is controlled to be 10 ppm or below, the content of key impurity elements As is controlled to be 1 ppm or below, the content of Pb is controlled to be 0.2 ppm or below, the content of Bi is controlled to be 0.2 ppm or below, the content of Cu is controlled to be 0.05 ppm or below, and the content of Fe is controlled to be 0.5 ppm or below.

The invention relates to the technical field of organic catalysis, in particular to a method for preparing glycolaldehyde by catalyzing formaldehyde hydroformylation. The method comprises the following steps: introducing CO and H2 into a mixed solution of paraformaldehyde, a rhodium compound, a ligand and a solvent, and reacting to prepare glycolaldehyde, the ligands comprise a ligand 1 and a ligand 2; the ligand 1 is selected from one or more of compounds as shown in the following L1-L8: # imgabs0 #; the structural formula of the ligand 1 is as shown in the specification, the structural formula of the ligand 2 is as shown in the specification, namely # imgabs1 # or # imgabs2 #, R1 is H, (CH2) ACH3, O-(CH2) ACH3, X or CX3, the value range of A is 0-3, and X is a halogen atom. According to the method disclosed by the invention, different ligands are subjected to dominant combination and cooperate with the rhodium-based catalyst, so that glycolaldehyde is obtained with high conversion rate and high selectivity under relatively mild conditions.

The invention discloses a preparation method of a carbon composite material doped with multiple metal elements. The preparation process comprises the following steps: S1, dispersing a porous carbon precursor, organic lithium fluoride, an organic rare earth compound and an organic catalyst in a solvent, performing hydrothermal reaction, and drying to obtain a porous carbon precursor loaded with lithium / rare earth element / catalyst; s2, uniformly mixing the obtained material with an activating agent and a doping agent, and activating at the temperature of 900-1100 DEG C to obtain multi-metal element doped porous carbon; and S3, carrying out reduction treatment and surface passivation treatment on the multi-metal element doped porous carbon to obtain the multi-metal element porous carbon composite material. According to the obtained material, lithium-doped and rare earth-doped porous carbon is utilized to improve the electronic conductivity of the material and increase the interlayer spacing of the carbon material, a carbon nanotube is grown by utilizing a catalyst to improve the conductivity of the material and reduce expansion, and through reduction and passivation treatment, the surface activity of the material is reduced, and the first efficiency is improved.

The invention discloses a preparation method of a multi-cured UV (ultraviolet) hot melt adhesive. A mixture of the UV hot melt adhesive is prepared from the following components in parts by weight: 40 to 70 parts of polyurethane acrylate oligomer, 5 to 20 parts of thermoplastic resin, 0.1 to 0.5 part of polymerization inhibitor and antioxidant, 2 to 5 parts of mixed photoinitiator and 5 to 20 parts of diluting monomer, wherein the polyurethane acrylate oligomer is synthesized by the following steps: S1, adding polyester polyol and a polyurethane metal organic catalyst into a flask, heating and uniformly stirring; s2, isocyanate is added in the step S1, heating reaction is performed, and a reactant A is obtained; s3, hydroxyl acrylate is added into the reactant A in the step S2, heating reaction is carried out, and the product polyurethane acrylate oligomer is obtained. The multi-curing LED-UV ultraviolet curing hot melt adhesive prepared by the preparation method disclosed by the invention has the characteristic of being capable of meeting the requirement of rapid ultraviolet curing, and the cohesiveness of the hot melt adhesive can be improved, so that the hot melt adhesive is an environment-friendly and efficient hot melt adhesive.

The invention provides a preparation method of sclareolide and a catalyst, and belongs to the technical field of organic catalysis. The method comprises the following steps: dissolving sclareol by using a first solvent, adding a catalyst, adjusting the pH value of the solution under microwave conditions, dropwise adding hydrogen peroxide, heating and stirring for reaction, separating the catalyst, reusing, extracting the product by using a second solvent, and heating and refluxing to obtain sclareolide; the catalyst is imidazolyl ionic liquid / polyethylene glycol / maleic acid modified graphene oxide loaded with vacancy heteropolyacid salt. According to the preparation method of sclareolide, microwave-assisted reaction is adopted, so that the product yield of sclareolide is greatly improved. According to the invention, two mutually compatible reaction systems of alcohol and water are adopted, so that the environmental protection property of the process is greatly improved, and meanwhile, under the action of the catalyst, the method has a phase catalytic transfer effect, the reaction efficiency is improved, the reaction condition is mild, the product yield is high, and the method has a wide application prospect.

The application belongs to the field of catalyst synthesis, and relates to a polymer polynuclear boron organic catalyst, a preparation method and application thereof, the preparation method of the catalyst comprises the following steps: adding tetrahydrofuran into a catalyst precursor, then adding a borohydride reagent drop by drop, heating the reaction mixture at 25-80 DEG C for 22-26 h, vacuum concentrating the reaction mixture to obtain a crude product, purifying the crude product by washing with pentane for 2-5 times, and vacuum drying the product at normal temperature for 10-14 h to obtain the catalyst; the catalyst precursor and a preparation method thereof are also provided; the polymer polynuclear boron organic catalyst provided by the application has the advantages of high activity, simple preparation method and low cost, and the catalyst can control the polymer substrate type and the polymer type by adjusting the reaction conditions, the catalytic system and the substrate, and can efficiently prepare polymers such as polyether, polyester and polycarbonate due to the synergistic effect of the polynuclear boron center, so that the types of the organic catalyst and the polymer are greatly expanded.

The invention relates to a titanium silicalite molecular sieve and a preparation method and application thereof in organic catalytic reaction, and the preparation method comprises the following steps: (1) mixing a titanium source, a crown ether compound and an optional solvent to obtain a titanium-containing precursor solution; (2) performing hydrolysis treatment on the titanium-containing precursor solution, a silicon source and a template agent in a contact manner to obtain a hydrolysis mixture; and (3) carrying out hydrothermal crystallization treatment, drying treatment and roasting treatment on the hydrolysis mixture. The problem that the content of non-framework titanium of the titanium silicalite molecular sieve is high can be effectively solved, and the catalytic activity of the titanium silicalite molecular sieve in an organic catalytic reaction is improved.

The application discloses a method for synthesizing nitrogen-containing heteroarene carboxylic acid compounds based on nitrogen-containing heteroarene carbon-hydrogen bond carboxylation reaction and belongs to the technical field of organic synthesis, and specifically comprises the following steps: adding a reaction substrate, an organic catalyst, a base and an additive into a reaction container, then adding a solvent under a CO2 atmosphere, and stirring and reacting at room temperature or under heating in a light irradiation condition; and performing post-treatment on a reaction product, separating and purifying the reaction product, and obtaining nitrogen-containing heteroarene carboxylic acid compounds and derivatives thereof. The scheme has the characteristics of mild reaction condition, wide reaction substrate range, good yield and good regioselectivity, and cheap and easily-obtained raw materials, can efficiently realize nitrogen-containing heteroarene carbon-hydrogen bond carboxylation reaction, synthesize important nitrogen-containing heteroarene carboxylic acid compounds, and has a good application prospect.

The invention discloses a high performance liquid chromatography analysis method for trace impurity content in an organic amine catalyst, and relates to the field of organic catalyst content analysis. Comprising the following steps: pretreating an organic amine catalyst sample, preparing a urea standard solution, performing HPLC (High Performance Liquid Chromatography) analysis and performing quantitative analysis by an external standard method, namely performing derivatization reaction on urea and benzaldehyde under an acidic condition, and successfully converting urea without ultraviolet absorption into dibenzylidene urea (DBU) with strong ultraviolet absorption, the technical blank of direct detection of urea is effectively filled, and the method is adaptive to a conventional ultraviolet / visible light detector to realize accurate detection. And the method has relatively high practical popularization and application values. The method has the advantages of being good in separation effect, high in sensitivity, easy and convenient to operate, high in reproducibility and the like, and can be widely applied to qualitative and quantitative analysis of various trace impurities in the organic amine catalyst.

The invention discloses a novel metal-free iodine-based binary catalyst system, belongs to the technical field of organic catalysis and high polymer materials, and is characterized in that an iodine-based charge transfer compound composed of I2, tetrabutylammonium acetate (TBAAc) and other quaternary ammonium salts catalyzes and oxidizes heterobutane and cyclic anhydride for controlled alternate ring opening copolymerization. In addition, the method has been effectively applied to ring-opening copolymerization by combining an epoxide and a cyclic anhydride. The catalyst system in the preparation method disclosed by the invention has the advantages of low cost, easiness in obtaining, low potential toxicity and biodegradability, and has a great practical application value.

The application discloses a triphenylmethane polyether dye and a preparation method thereof, and the preparation method comprises the following steps: (1) adding an organic catalyst and an oxidant into a triphenylmethane polyether dye leucoaqueous solution in the interval of 40-60 DEG C, adding an acid-binding agent to maintain a proper pH, and completing oxidation; the organic catalyst is a ferrocene-rotene iron compound; (2) adjusting the pH with an acid-binding agent aqueous solution, removing the organic catalyst by hot filtration, removing water through vacuum distillation of the filtrate, and performing pressure filtration to obtain the triphenylmethane polyether dye. The improved rotene iron catalyst is used in the application, the catalytic effect is obviously improved, the reaction temperature and activation energy are reduced, the defects of excessive hydrogen peroxide oxidation are overcome, and the obtained product meets the EN71-3 standard.

The invention provides a preparation method and application of an amorphous zirconium-doped manganese oxide catalyst, and belongs to the field of organic catalytic synthesis. The catalyst is Zr-MnO2-x, and is rich in lattice oxygen with high activity and high stability; x is the molar ratio of Zr to the sum of Mn and Zr, and x is larger than or equal to 0.2 and smaller than or equal to 0.6; zirconium mainly exists in the form of zirconium hydroxide. The preparation method comprises the following steps: slowly dropwise adding a mixed salt solution of a zirconium source and a manganese source into a precipitant under a continuous stirring condition, and carrying out a co-precipitation reaction; after the reaction is completed, standing and aging, carrying out solid-liquid separation and collecting a precipitate; and washing and drying to obtain the amorphous zirconium-doped manganese oxide catalyst which is used for catalyzing aniline and derivatives thereof to synthesize azobenzene compounds. According to the invention, the characteristic of'difunctional lattice oxygen 'with high activity and high stability is introduced through zirconium doping, and the catalyst has the advantages of high activity, high selectivity, wide substrate applicability, excellent stability and reusability and the like when used for catalytic synthesis of azobenzene compounds.

The invention discloses an ultrasonic enhanced organic catalytic continuous flow polypeptide synthesis method. The preparation method comprises the following steps: (1) respectively dissolving an amino alcohol initiator, an organic catalyst and an amino acid intracyclic anhydride monomer in an organic solvent; (2) injecting the three solutions into a tubular reactor equipped with an ultrasonic water bath constant-temperature oscillator; (3) realizing continuous flow precise synthesis of polypeptide with different molecular structure parameters by adjusting the types of three reactants, namely an amino alcohol initiator, an organic catalyst and an amino acid intracyclic anhydride monomer, the sequence of injecting the reactants into the reactor and the relative speed of injecting the reactants into the reactor; and (4) carrying out flowing ring-opening polymerization reaction, flowing into a collecting bottle containing a reaction terminator, precipitating, centrifuging, and carrying out vacuum drying to remove the residual solvent, thereby obtaining the polypeptide. The method provided by the invention has the characteristics of high synthesis efficiency, no metal catalyst residue in the product, easy regulation and control of product structure parameters, easy non-amplification, easy large-scale production and easy automatic production.

The invention discloses a gas decontamination and hydrolysis composite tank and a blast furnace gas fine desulfurization system, comprising a reaction tank body, wherein a gas inlet and a gas outlet are radially arranged on the reaction tank body, three mesh partitions are arranged inside the reaction tank body, the mesh partitions are arranged parallel to the center line of the reaction tank, and the gas flows radially along the tank body. The mesh partitions divide the interior of the reaction tank body into a gas distribution chamber, a decontamination chamber, a catalytic hydrolysis chamber and a gas collecting chamber. The gas inlet is arranged on the gas distribution chamber side of the reaction tank body, and the gas outlet is arranged on the gas collecting chamber side of the reaction tank body. A decontamination agent is placed in the decontamination chamber, and an organic catalytic converter is placed in the catalytic hydrolysis chamber. The gas enters the gas distribution chamber from the gas inlet, flows uniformly toward the decontamination chamber and the catalytic hydrolysis chamber, and is discharged through the outlet after merging in the gas collecting chamber. The gas has low resistance along the gas flow and low pressure loss, and can meet the requirements of removing harmful impurities in blast furnace flue gas and catalytically hydrolyzing organic sulfides.

The application discloses a supported chiral phosphine heterogeneous catalyst and a preparation method and application thereof, and relates to the technical field of heterogeneous catalyst preparation. The method comprises the following steps: mixing hollow mesoporous polystyrene nanospheres, chiral phosphine and DCE, stirring, adding FDA, stirring, adding concentrated sulfuric acid dropwise, and reacting to obtain a reactant one; and mixing the reactant one, toluene, tetramethyldisiloxane and tetraisopropyl titanate, and reacting under temperature rise to obtain the supported chiral phosphine heterogeneous catalyst. The application is simple and convenient in a one-pot method, and can efficiently anchor the chiral phosphine and its oxide catalyst to the carrier. The application solves the problems of complicated modification in the existing organic catalyst immobilization process and mass transfer limitation of the prepared catalyst.

The application discloses a single-molecule bifunctional organic catalyst, and a structural formula is shown in the following formula (I), wherein X is selected from a urea or thiourea containing group, a structural formula is shown in the following formula (II), Y is selected from a potassium alcoholate or sodium alcoholate group, a structural formula is shown in the following formula (III), and L is selected from an unsubstituted C2-C4 alkyl group; the single-molecule bifunctional organic catalyst disclosed by the application has a novel structure, has super-high activity and high controllability when catalyzing ring-opening polymerization of a lactone, and the highest turnover number (TON) can reach 900, and the highest turnover frequency (TOF) can reach 4860 min ‑1 , and the prepared polymer has high molecular weight and low molecular weight distribution.

This invention provides a neutral-electron-reversed carbene, its preparation method, and its applications, belonging to the fields of organic chemistry and organic catalysis. The neutral-electron-reversed carbene described in this invention has the structure shown in formula (I). This invention synthesizes the neutral-electron-reversed carbene in one step by reacting a diazo compound as a precursor with a rhodium complex, followed by nitrogen removal and COD (1,5-cyclooctadiene) removal processes. The reaction conditions of this invention are simple, and the yield is good. Stable separation of neutral-electron-reversed carbene is achieved for the first time.

A rolling roll according to an embodiment of the present invention comprises: a roll base material; and a chromium-containing plating layer which is formed on the roll base material and in which the maximum length of cracks formed on the surface thereof is 5 µm or less. A rolling roll according to another embodiment of the present invention comprises: a roll base material; a chromium-containing plating layer formed on the roll base material; and a first coating layer formed on the chromium-containing plating layer and containing a titanium nitride. A method for manufacturing a rolling roll according to another embodiment of the present invention comprises the steps of: forming surface recesses and projections on the surface of a roll base material; forming a chromium-containing plating layer on the roll base material by using a plating solution containing a chromium-containing raw material and sulfuric acid; and applying a metal nitride onto the chromium-containing plating layer. In the step of forming the chromium-containing plating layer, the plating solution further contains a sulfonic acid-based organic catalyst, or plating is performed in a state in which the plating solution has been heated to 65-90°C. A method for manufacturing a secondary battery according to another embodiment of the present invention comprises the steps of: forming an electrode active material layer on a current collector; and rolling the electrode active material layer using said rolling roll.

The invention relates to a catalyst composition and a preparation method of thermotropic liquid crystal polyarylester under catalysis. The catalyst composition comprises an organic catalyst and an inorganic catalyst. The polymerization reaction rate is obviously improved, and the thermotropic liquid crystal polyarylester is efficiently prepared. The thermotropic liquid crystal polyarylester prepared by the method has excellent comprehensive performance, high modulus and high thermal stability, and has important application value in the field of high-performance composite materials.

The invention provides a catalyst as well as a preparation method and application thereof, and relates to the technical field of organic catalytic synthesis, the catalyst comprises a mesoporous zirconium-silicon composite oxide, and active metal cobalt and auxiliary metal which are loaded on the mesoporous zirconium-silicon composite oxide; the auxiliary metal comprises one or two of copper metal and nickel metal. Based on the catalyst provided by the invention, the problems of high cost, low active metal utilization efficiency, poor carrier stability and many byproducts of the catalyst in the prior art are solved.

The invention relates to a synthetic method of high polymer material polyester, in particular to a method for synthesizing polyester through ring opening polymerization of cyclic ester monomers. According to the invention, an imidazolyl ionic liquid with 1-alkyl-3-methylimidazole cation as a catalyst is used for catalyzing ring opening polymerization of a cyclic ester monomer to obtain polyester. According to the invention, the imidazolyl ionic liquid is used as a catalyst, the catalytic activity is high, the cyclic ester monomer can be subjected to ring-opening polymerization without an alcohol initiator, and under the condition of short reaction time, the monomer conversion rate is high, the number-average molecular weight of the product is high, and the molecular weight distribution is narrow; the technical problem that an existing organic catalyst applied to catalysis of polyester ring-opening polymerization is relatively low in catalytic activity is solved. The imidazolyl ionic liquid catalyst has the characteristics of low toxicity and no pollution; the method for catalyzing ring opening polymerization of the cyclic ester monomer through the imidazolyl ionic liquid is a green synthesis method of polyester.

The present invention discloses a method for synthesizing dithiocyclic carbonates, belonging to the technical field of organic catalysis. By using a brand-new organic neutral catalyst, the [3+2] cycloaddition reaction of epoxides and carbon disulfide can be achieved at room temperature within a short time, and dithiocyclic carbonates can be obtained with high selectivity. This catalytic system has excellent catalytic effects on different aliphatic and aromatic epoxides, and the yields of most of them reach over 90%. The dithiocyclic carbonate products have no metal residues and have great potential for commercial applications in fields such as biomedicine and polymer production where strict requirements are imposed on the content of metal residues.

The present invention relates to the field of organic catalytic synthesis, and discloses a niobium (Nb)-based catalyst and a synthesis method for directly performing substitution amination of an alcohol compound with an organic amine to synthesize a corresponding secondary amine. Through the catalyst and method of the present invention, an alcohol compound and an organic amine can be used as raw materials to undergo a substitution amination reaction in a reaction device to obtain a secondary amine with a high yield. There are mainly three traditional methods for catalytic synthesis of secondary amines: 1) Through the method of borrowing hydrogen or reductive catalytic amination, secondary amines are synthesized through intermediate products aldehydes and ketones, and common catalysts are noble metal catalysts such as platinum, palladium, and ruthenium; 2) Through the substitution amination route, catalysts prepared using trifluoromethanesulfonates, etc., and secondary amines are synthesized under the action of an auxiliary agent, or secondary amines are obtained by reacting with homogeneous catalysts such as ferric chloride. Compared with the above three methods, the method of the present invention is a heterogeneous catalytic reaction, does not require the addition of an auxiliary agent, the product is easy to separate, the synthesis process is pollution-free, and compared with noble metal catalysts such as platinum, palladium, and ruthenium, the catalyst has low cost and good stability.

The present application relates to a kind of sulfonated metal Salen and polyether ionic liquid binary system catalysis method for preparing cyclic carbonate by the ring addition of CO2 and epoxide;In order to improve the shortcomings that metal complex catalyst is difficult to realize recycling and organic catalyst has lower catalytic activity, the present application combines metal complex catalyst with organic catalyst, creates a kind of sulfonated metal Salen and polyether ionic liquid binary catalytic system, realizes the efficient synergistic catalysis of sulfonated metal Salen and polyether ionic liquid;The binary catalyst has the advantages of simple construction, high catalytic activity and selectivity, easy separation cycle, long life and low loss, meets the process requirements of green synthesis.

The application provides a method for synthesizing 4,4'-diamino-3,3'-dimethyl biphenyl methane, and belongs to the field of organic catalytic synthesis. The method is characterized in that o-toluidine and formaldehyde are used as raw materials, a catalyst and a reaction solvent are added, and 4,4'-diamino-3,3'-dimethyl biphenyl methane is catalytically synthesized. The synthesis route of the application has the advantages of simple reaction operation, mild conditions, avoidance of the use of hydrochloric acid, recyclability of the catalyst, high conversion rate and selectivity of the experiment, and convenience of post-treatment.

The application belongs to the technical field of organic synthesis, and particularly relates to a kind of bromine-containing isoindoline-1-ketone compound and preparation method thereof.The preparation method of the bromine-containing isoindoline-1-ketone compound uses commercially available aldehyde-derived imine as raw material, is reacted with aryl bromide oxazoline compound under butyl lithium condition, and then is subjected to acid-mediated cascade cyclization process, to efficiently construct isoindoline-1-ketone skeleton.The isoindoline-1-ketone compound can be directly used as an organic catalyst, the N-H functional group remaining in the structure of the isoindoline-1-ketone compound has reactivity, can be coupled with other bioactive molecules as a key connection site, to construct functional derivatives, the amide carbonyl group thereof can be further reduced, to be converted into pyrrolidine structural unit, and the structure itself can be used as a catalytically active center, to expand its application in the field of catalysis.

The invention discloses a method for synthesizing a chiral pyrazolone imine derivative based on an asymmetric aza-Henry reaction catalyzed by an organic catalyst, which comprises the following steps: placing a pyrazolone imine compound and a nitroalkane compound in a solvent, adding the organic catalyst, and reacting at-78-60 DEG C while stirring to prepare the target product chiral pyrazolone imine derivative. Or placing the pyrazolone imine compound and brominated nitromethane in a solvent, then adding an organic catalyst, carrying out a stirring reaction at-78 to 60 DEG C to prepare a chiral pyrazolone imine derivative, and further carrying out debromination to obtain the target product, namely the chiral pyrazolone imine compound. The asymmetric aza-Henry reaction of the pyrazolone imine compound and the nitroalkane compound or the bromo-nitromethane is successfully realized on the basis of the small organic molecule catalyst, and the asymmetric aza-Henry reaction has the advantages of low catalyst consumption, high reaction rate (the fastest reaction rate is 0.5 h), high enantioselectivity (the highest reaction rate reaches 96% ee), good universality of reaction substrates and the like.

The invention provides a preparation method of high-purity bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, and belongs to the technical field of polymer synthesis, and the preparation method comprises the following steps: reacting diamine with maleic anhydride in an organic solvent to obtain bismaleamic acid, and carrying out dehydration by taking inorganic acid or inorganic acid salt as a dehydration catalyst to obtain the high-purity bis (3-ethyl-5-methyl-4-maleimidophenyl) methane. The preparation method comprises the following steps: carrying out dehydration ring-closure reaction on bismaleamic acid to prepare bis (3-ethyl-5-methyl-4-maleimidophenyl) methane; the inorganic acid is phosphoric acid, nitric acid or sulfuric acid, and the inorganic acid salt is sodium hydrogen sulfate or sodium dihydrogen phosphate; the dosage of the organic solvent is not more than 6 times of the equivalent weight of diamine. The high-purity bis (3-ethyl-5-methyl-4-maleimidophenyl) methane is prepared by adopting an inorganic acid catalysis system and a low-temperature dehydration process, so that the problems of organic catalyst residue, excessive solvent, bottleneck of product purity, overhigh process temperature, chromatic aberration of the product, limited application field and the like are solved, and the yield and purity of the product are improved.