52 results about "Nitroaniline" patented technology

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

The application discloses a preparation method of triclabendazole, and relates to the technical field of raw medicine synthesis. The method comprises the following steps: taking 4-chloro-5-(2,3-dichlorophenoxy)-2-nitroaniline as raw material, and sequentially performing reduction in an iron powder ethanol system, ring closure with a sulfur-containing ring closure reagent, methylation with dimethyl sulfate, and crystallization and purification in ethanol to obtain triclabendazole finished products. In the reaction process, iron mud is removed through pressure filtration, ethanol is recovered through distillation, and the ring closure intermediate is precipitated under acidic conditions. The process condition is clear, the operation is simple, the emission of hazardous waste can be reduced, the utilization rate of solvents and the purity of products can be improved, and the method is suitable for industrialized production of triclabendazole raw medicine.

The invention relates to an environment-friendly stripping agent of photosensitive ink for electroplating shielding, and belongs to the technical field of stripping agents. The preparation method comprises the following steps: carrying out nucleophilic addition on phosphorous acid and diethylene glycol monobutyl ether to obtain a modified precursor containing a phosphoester structure, carrying out Michael addition on the modified precursor and ortho-aminophenol to obtain a modified monomer, carrying out diazotization reaction on the modified monomer and ortho-nitroaniline, and then reducing to obtain the 2-(2-nitrophenyl)-1, 2, 4-thiadiazole. And finally, compounding the modified corrosion inhibitor with a stripping agent system, so as to obtain the environment-friendly stripping agent for the photosensitive ink for electroplating shielding. The environment-friendly stripping agent of the photosensitive ink for electroplating shielding has the advantages of environment friendliness, no toxicity, high stripping efficiency, broad-spectrum corrosion inhibition and few surface residues.

The invention relates to a preparation method of an environment-friendly dye intermediate and the environment-friendly dye intermediate prepared by the method. The preparation method of the environment-friendly dye intermediate comprises the following steps: a dissolving step: 2-R-4-nitroaniline and halate are dissolved in an organic solvent to obtain an initial solution, the chemical structural formula of the 2-R-4-nitroaniline is shown in the formula (1), R represents-Cl,-Br or-CN: (1); a reaction step: hydrogen chloride gas is introduced into the initial solution for a reaction, and a reaction product is obtained; and a separation step: carrying out separation treatment on the reaction product to obtain mother liquor and a crude product. The preparation method of the environment-friendly dye intermediate is more reasonable in process, and the organic solvent is used in the preparation process, so that the environment-friendly index of the product reaches the standard, and no high-COC and / or PCP sewage is discharged.

This invention belongs to the field of organic chemical synthesis technology, specifically relating to a method for synthesizing 2-fluoro-3-aminobenzoic acid, an important chemical intermediate. Specifically, o-nitroaniline is condensed with hydrated trichloroacetaldehyde and hydroxylamine hydrochloride to obtain 2-(hydroxyimino)-N-(2-nitrophenyl)acetamide; the resulting product undergoes an intramolecular Beckmann rearrangement to generate 7-nitroindigo; 7-nitroindigo undergoes Bayer-Villedge oxidation to generate 2-amino-3-nitrobenzoic acid; 2-amino-3-nitrobenzoic acid undergoes diazotization and halogenation reactions to generate 2-fluoro-3-nitrobenzoic acid or 2-chloro-3-nitrobenzoic acid; 2-fluoro-3-nitrobenzoic acid can be further reduced by nitro to obtain 2-fluoro-3-aminobenzoic acid; or, 2-chloro-3-nitrobenzoic acid can be esterified to obtain 2-chloro-3-nitrobenzoic acid ester, which can then be fluorinated, saponified, and reduced to obtain 2-fluoro-3-aminobenzoic acid. The raw materials of this invention are low in cost and readily available, and the entire reaction route has specific regioselectivity, making it suitable for industrial production.

The invention discloses water-based ink for paperboard printing and a green printing process of the water-based ink, and relates to the technical field of water-based ink for paperboards. Sodium nitrite is taken and added into deionized water to be evenly mixed, and a sodium nitrite solution is obtained; adding hydrochloric acid and acetic acid into deionized water, and uniformly mixing; 4-methyl-2-nitroaniline is added, and stirring is carried out; cooling, adding a sodium nitrite solution, and reacting to obtain a solution; adding sodium hydroxide into deionized water, uniformly mixing, adding azoic coupling component, uniformly mixing, and cooling; slowly adding the solution and reacting; heating, reacting and cooling; and carrying out suction filtration, drying and refining to obtain the water-based pigment. Taking a polyurethane emulsion and a polyacrylate emulsion, and uniformly mixing the polyurethane emulsion and the polyacrylate emulsion to obtain a polyurethane-polyacrylate emulsion; taking the polyurethane-polyacrylate emulsion, water-based pigment, polyethylene wax emulsion, a wetting agent, a flatting agent, deionized water and absolute ethyl alcohol, and dispersing to obtain the water-based ink.

The invention provides a preparation method of 2-chloro-4-nitro-6-bromoaniline and a diazonium salt of the 2-chloro-4-nitro-6-bromoaniline. The preparation method of 2-chloro-4-nitro-6-bromoaniline comprises the following steps: a chlorination step: carrying out a chlorination reaction on paranitroaniline to obtain a chlorination reaction product, and carrying out post-treatment on the chlorination reaction product to obtain a 2-chloro-4-nitroaniline product; wherein the water content of the 2-chloro-4-nitroaniline product is 60% or below; and a bromination step: mixing the 2-chloro-4-nitroaniline product with sulfuric acid to obtain a sulfuric acid slurry, and carrying out a bromination reaction on the sulfuric acid slurry and a brominating agent to obtain a 2-chloro-4-nitro-6-bromoaniline reaction solution. The 2-chloro-4-nitroaniline is prepared by taking paranitroaniline as an initial raw material through chlorination reaction and post-treatment, and then the sulfuric acid is taken as a solvent to penetrate through the subsequent reaction, so that the separation process is simplified, the production cost is reduced, and waste and pollution are reduced.

The application belongs to the technical field of synthesis of organic light-emitting material intermediates, and particularly relates to a preparation method of 2-bromo-9-phenyl-9H-carbazole, which comprises the following steps: under inert gas, 2-nitroaniline and a bromine reagent are subjected to an electrophilic aromatic substitution reaction to generate an intermediate A-1; under acidic conditions, sodium nitrite and the intermediate A-1 are subjected to a diazotization reaction to generate a diazonium salt, and then under alkaline conditions, the diazonium salt is coupled with benzene to generate an intermediate A-2; the intermediate A-2 and triphenylphosphine are subjected to a reaction to generate a carbene, and then the carbene is subjected to a ring-closing reaction to generate an intermediate A-3; and the intermediate A-3 and bromobenzene are subjected to an Ullmann reaction to obtain 2-bromo-9-phenyl-9H-carbazole. The new method has the advantages of cheap and readily available raw materials, simple process, high yield, high continuous degree of reaction, short production cycle, low production cost and suitability for industrial production.

The utility model discloses microwave vacuum drying equipment for ortho-nitroaniline, and belongs to the technical field of ortho-nitroaniline drying. The device comprises an outer machine shell, a feeding port is formed in one side of the outer machine shell, a sealing cover is movably hinged to one side of the feeding port, and a microwave generating device is fixedly arranged on the sealing cover; a crushing cylinder is rotationally arranged on the side, close to the feeding port, in the outer machine shell, the end, close to the feeding port, of the crushing cylinder is open, the other end of the crushing cylinder is blocked, screening holes are formed in the side wall of the crushing cylinder, the outer side of the crushing cylinder is slidably sleeved with a sealing cylinder, and the sealing cylinder is in sliding fit with the outer machine shell; a pushing mechanism used for pushing the sealing cylinder to move along the smashing cylinder is arranged on the outer machine shell. When the device is used, o-nitroaniline powder is heated through the microwave generating device, and the motor drives the crushing cylinder to rotate, so that the o-nitroaniline powder in the sealing cylinder can roll continuously, and the o-nitroaniline powder is uniformly heated.

The utility model discloses a feeding device for paranitroaniline production. The feeding device comprises a mixing tank body, when p-nitroaniline production feeding is carried out and a feeding cover on the left side needs to be opened, a pressing block is pressed towards the inner side, the pressing block drives a connecting plate and a sliding block to move towards the inner side along a sliding rail, the connecting plate drives a moving column to move towards the inner side, the moving column drives an inserting column to move towards the inner side, and the inserting column moves towards the inner side to extrude a reset spring; when an inserting column moves towards the inner side to an inserting hole to lose contact, a handle is held to pull up the feeding cover on the left side to open the feeding cover, after materials needing to be added are poured into the feeding box, a driving motor is started to drive a spiral conveying blade to rotate to convey the materials into the mixing tank body, and then paranitroaniline can be produced and processed; therefore, the charging device has the advantage of facilitating charging for paranitroaniline production, charging for paranitroaniline production can be automatically carried out, the blockage condition is avoided, and the paranitroaniline production time is shortened.

The present application relates to an electron-withdrawing group terminated polyimide covalent organic framework material and a preparation method and application thereof. The present application utilizes 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and tetra(4-aminophenyl)methane monomers to prepare a polyamide acid covalent organic framework, and utilizes 4-aminobenzonitrile, 4-amino-trifluorotoluene, 4-nitroaniline and 4-chloroaniline to perform termination, thereby preparing an electron-withdrawing group terminated polyimide covalent organic framework material. The rich pore structure of the COF framework provides a fast ion transmission channel, promotes the transport of carriers, the Lewis acidity formed by the end-capped electron-withdrawing group adjusts the electron cloud density of the COF framework through an inductive effect, and an electron-deficient domain is constructed. In a lithium metal battery system, it can guide the uniform distribution of lithium ions, solve the problem of lithium dendrite growth; when loaded on a lithium-sulfur battery positive electrode material, it can lead the directional movement of polysulfides to complete the down-order conversion reaction, thereby obtaining a lithium-sulfur battery with long cycle life.

This invention provides a one-step method for preparing 4-substituted indole. Using 2-methyl-3-nitroaniline as a raw material, acetic anhydride is slowly added after dissolving it in DMF solvent with low-temperature stirring. After the condensation reaction is completed, DMF-DMA and tetrahydropyrrole are directly added. A cyclization reaction is carried out in stages with controlled temperature, and methanol byproducts are evaporated. After cooling the reaction solution, ice water is added dropwise to crystallize and obtain a crude product. This crude product is then dissolved in 2-methyltetrahydrofuran, washed with hydrochloric acid, washed with water, washed with a saturated sodium bicarbonate aqueous solution, decolorized with activated carbon, concentrated, and recrystallized with acetonitrile to obtain high-purity 4-substituted indole. This invention employs a one-step continuous reaction, eliminating multiple purification steps such as intermediate separation, washing, and drying, significantly simplifying the process and shortening the production cycle. Compared with traditional processes, the yield is significantly improved, with fewer byproducts, lower energy consumption, and smaller emissions. The process is stable, reliable, simple, and safe to operate, suitable for industrial production, and meets the requirements of high-end pharmaceutical intermediates.

The invention belongs to the technical field of organic synthesis, and discloses a preparation method of an intermediate 3, 4-diaminobromo-benzene, which comprises the following steps: S1, adding o-nitroaniline and a solvent, dropwise adding hydrobromic acid, dropwise adding hydrogen peroxide, carrying out heat preservation reaction, and treating after the reaction is completed to obtain a yellow solid; in the step S2, IM-1, a solvent, a catalyst and activated carbon are added, hydrazine hydrate is dropwise added, a stirring reaction is performed after dropwise adding, after the reaction is completed, activated carbon is filtered, the solvent is spin-dried, water is added for cooling, crystallization is performed, and a yellow solid is obtained through filtering. According to the method, o-nitroaniline is adopted as a starting raw material, and 3, 4-diaminobromo-benzene is prepared through hydrobromic acid substitution and hydrazine hydrate reduction. The invention discloses a drug molecule modular design, synthesis and optimization method based on molecular blocks, and aims to improve the research and development efficiency and molecular diversity of new drugs.

The invention discloses a method for synthesizing 2, 6-dichloroaniline through light induction, and relates to the technical field of organic synthesis.The method comprises the steps that aniline and acetic anhydride are mixed and stirred, and acetanilide is obtained; acetanilide is dropped into concentrated sulfuric acid to obtain a mixed solution, the mixed solution and concentrated sulfuric acid are subjected to a continuous flow reaction through a microchannel according to a preset molar ratio, and p-nitroacetanilide is obtained; the method comprises the following steps: mixing p-nitroacetanilide and a photocatalytic solution, placing the mixture in a photocatalytic reactor, and in an inert gas atmosphere, carrying out a catalytic chlorination reaction through irradiation of visible light with a preset wavelength to obtain 2, 6-dichloro-4-nitroacetanilide; the preparation method comprises the following steps: mixing 2, 6-dichloro-4-nitroacetanilide with a hydrochloric acid solution, and heating and refluxing to obtain 2, 6-dichloro-4-nitroaniline; the method comprises the following steps: by taking palladium on carbon as a catalyst, carrying out a denitrification reaction on 2, 6-dichloro-4-nitroaniline under the action of hydrogen to obtain 2, 6-dichloroaniline; the method can solve the technical problems of poor reaction selectivity, low yield and loss of traditional synthesis of 2, 6-dichloroaniline.

The invention discloses a method for synthesizing N, N '-dialkyl p-phenylenediamine as shown in a formula (I) or a mixture thereof and an anti-aging agent mixture produced by adopting the method. Comprising the following steps: adding a raw material A selected from paranitroaniline and p-phenylenediamine, a raw material B selected from a compound as shown in a formula (II), a compound as shown in a formula (III) and cyclohexanone, and a catalyst into a reaction device, and carrying out hydrogenation reaction under a hydrogen condition to obtain N, N '-dialkyl p-phenylenediamine as shown in a formula (I) or a mixture thereof, wherein the raw material A and the raw material B are fed in a liquid form; in the formula (I), the formula (II) and the formula (III), R1, R2, R3 and R4 are respectively and independently H or C1-C6 alkyl, or-CHR1R2 and-CHR3R4 are independently cyclohexyl. According to the method disclosed by the invention, high-selectivity and low-cost production of the N, N '-dialkyl p-phenylenediamine can be realized, and the reaction conditions are milder and more controllable. (I) (II) (III)

The utility model relates to the field of nitroaniline, and discloses a drying machine for paranitroaniline production, which comprises a frame, a placing box is fixedly mounted at the top of the frame, a connecting box is fixedly mounted on the left side of the placing box, and a heating box is fixedly mounted on the left side of the connecting box. A heating assembly for heating nitroaniline is arranged in the heating box, and a rotating assembly for stirring nitroaniline is arranged in the placing box. Through mutual cooperation of the electric heating wire, the conveying pipe and the fan, when nitroaniline is placed in the placing box, the electric heating wire can be electrified, when the electric heating wire reaches enough temperature, the fan can be started at the moment, the fan can extract outside air into the heating box, and the nitroaniline can be heated in the heating box. And then hot air in the heating box can enter a conveying pipe, the conveying pipe conveys heat of the hot air into the containing box, and therefore nitroaniline in the containing box can be dried.

The invention relates to the technical field of synthesis of organic compounds, and particularly discloses a synthesis process of paranitroaniline. The synthesis process comprises the following steps: (1) preparing strong ammonia water with the concentration of 38-42% by using an ammonia water preparation unit; (2) adding p-nitrochlorobenzene, stronger ammonia water and an auxiliary agent into the reaction kettle, and then carrying out heat preservation reaction for 14-16 hours under the conditions that the temperature is 150-170 DEG C and the pressure is 5.6-6.2 MPa; the auxiliary agent comprises modified cyclodextrin and trehalose; and (3) transferring the material in the reaction kettle into a water washing kettle after pressure relief, carrying out water washing stirring for 1-2 hours, and carrying out centrifugal separation on the material liquid after water washing to obtain p-nitroaniline. According to the synthesis process disclosed by the invention, the problem of balance between main reaction efficiency and side reaction inhibition is solved from a reaction mechanism level through compounding and synergy of the modified cyclodextrin and the trehalose, and finally, high yield and high purity in the paranitroaniline synthesis process are synchronously achieved.

The invention relates to the technical field of 4, 4 '-diaminodiphenylamine, in particular to a synthesis process of 4, 4'-diaminodiphenylamine, which comprises the following steps: dissolving parachloronitrobenzene, paranitroaniline and alkali in an organic solvent, heating, stirring, pouring into ice water, filtering, washing and drying to obtain 4, 4 '-dinitrodiphenylamine; adding the mixture, a catalyst and an organic solvent into a high-pressure reaction kettle, introducing hydrogen after nitrogen replacement, heating and stirring, filtering the catalyst after the reaction is finished, and recovering and reusing the catalyst; according to the synthesis process of 4, 4 '-diaminodiphenylamine adopting the steps, the reaction process is shortened, the steps of separation and purification of intermediate products are reduced, the production efficiency is improved, the loss in the production process is reduced, and the product with high purity and high yield is obtained.

This invention relates to a method for preparing 2',4-dichloro-2-aminodiphenyl ether, belonging to the field of chemical synthesis technology. The preparation method is as follows: S1, m-dinitrobenzene undergoes selective hydrogenation to obtain m-nitroaniline; S2, in a solvent, m-nitroaniline reacts with N-chlorosuccinimide to obtain 2-chloro-5-nitroaniline; S3, 2-chloro-5-nitroaniline, o-nitrophenol, a base, and a solvent undergo a co-heated reaction to obtain 2',4-dinitro-2-aminodiphenyl ether; S4, 2',4-dinitro-2-aminodiphenyl ether is dissolved in a solvent, and FeCl3 solution, sodium chloride, and Oxone are added. The reaction is catalyzed under ultraviolet light to obtain 2',4-dichloro-2-aminodiphenyl ether. The preparation method of this invention uses readily available raw materials, has good reaction efficiency, produces less waste, is cleaner and more environmentally friendly, and has a high conversion rate, making it suitable for industrial application.

The application discloses N-o-tolyl-N'-(1-methyl-2-benzyl) ethyl p-phenylenediamine and a preparation method and application thereof. The product is prepared from p-chloronitrobenzene and 2-methylaniline through a nucleophilic substitution reaction to obtain N-o-tolyl p-nitroaniline, and then the N-o-tolyl p-nitroaniline and benzylacetone are subjected to a catalytic reduction reaction under high temperature and high pressure conditions to obtain the final product. The product has excellent ozone protection effect and anti-crack performance, and can obviously improve the red discoloration phenomenon of the tire side caused by the migration of the antioxidant.

The invention provides a preparation method of L-gamma-glutamyl-3-carboxyl-4-nitroaniline ammonium salt. The preparation method comprises the following steps: (1) mixing 5-amino-2-nitrobenzoic acid and an alkylating reagent for reaction to obtain an intermediate 1; (2) mixing and reacting the intermediate 1 with Boc-L-glutamic acid-1-tert-butyl ester and a condensing agent to obtain an intermediate 2; (3) mixing the intermediate 2 with a hydrolysis reagent for reaction to obtain an intermediate 3; and (4) mixing the intermediate 3 with alkali to react, so as to obtain the L-gamma-glutamyl-3-carboxyl-4-nitroaniline ammonium salt. According to the preparation process of the L-gamma-glutamyl-3-carboxyl-4-nitroaniline ammonium salt, the steps of esterification, condensation, deprotection and salification are sequentially performed, the reaction conditions are mild, side reactions are few, industrial amplification production of high-purity products is easier to realize, and a safe, efficient and green new way is provided for stable supply of Glupa-C.

The invention provides a method for continuously synthesizing o-phenylenediamine. The method comprises the following steps: step 1, filling a multistage tubular fixed bed reactor with a solid catalyst; 2, preheating a methanol solution of o-nitroaniline, sequentially passing through the multi-stage tubular fixed bed reactors, introducing hydrogen through aeration ports of the multi-stage tubular fixed bed reactors, fully mixing with the materials, and reacting for 1-10 hours at the temperature of 60-170 DEG C and the pressure of 0.7-2.5 MPa to obtain an o-phenylenediamine synthetic solution; and 3, continuously extracting an o-phenylenediamine synthetic liquid, and carrying out desolvation, light component removal and rectification to obtain an o-phenylenediamine finished product. The continuous synthesis method provided by the invention solves the problems of poor continuity, complex post-treatment process and the like of the existing synthesis process, and has the advantages of high catalytic efficiency, simple process flow and low catalyst consumption.

The utility model discloses a blanking structure for paranitroaniline processing, which comprises a placing plate, the top of the placing plate is fixedly connected with a support frame, the top of the support frame is fixedly connected with a circular plate, the top of the circular plate is fixedly connected with a stock bin, the left side of the placing plate is fixedly connected with a reinforcing frame, and the top of the placing plate is provided with a stirring mechanism. A discharging mechanism is arranged on the left side of the containing plate. By using the stirring mechanism, nitroaniline in the stock bin can be stirred and scattered, by using the discharging mechanism, discharged nitroaniline can be more uniform, and the problem that when nitroaniline is discharged, due to the fact that the nitroaniline has high hygroscopicity, moisture in air can be easily absorbed, and the nitroaniline cannot be uniformly discharged is solved. The problems that the physical state of materials is changed, the caking phenomenon often occurs, the uniformity of discharging is seriously disturbed, and the proportioning accuracy of nitroaniline and other raw materials is badly affected due to non-uniform discharging are solved, and the discharging device has the advantage of being convenient to discharge.

This invention relates to the field of catalytic hydrogenation technology, and provides a fixed-bed continuous catalytic hydrogenation system for preparing p-phenylenediamine. The method includes: Step A, p-nitroaniline and solvent are mixed in a material mixing device in advance according to a certain proportion to obtain a p-nitroaniline solution, and then the p-nitroaniline solution and hydrogen are preheated separately in preheaters; Step B, the preheated reaction material is mixed in a gas-liquid mixer and then enters a fixed-bed reactor pre-loaded with a multilayer catalyst, where a catalytic hydrogenation reaction occurs to generate the product material; Step C, the product material is separated by a gas-liquid separator to obtain p-phenylenediamine solution and hydrogen gas, the p-phenylenediamine solution is post-treated to obtain p-phenylenediamine, and the solvent is recovered and reused. This invention effectively overcomes the pain point of the existing batch catalytic hydrogenation process, which has a single-batch reaction time of 4-14 hours, and achieves a significant reduction in the reaction time of continuous catalytic hydrogenation; it can also effectively ensure product selectivity, easy product separation, good safety, significantly reduced cost, and easy industrial application.

The application relates to the technical field of organic compound synthesis, and particularly discloses a synthesis process of p-nitroaniline. The synthesis process of p-nitroaniline comprises the following steps: (1) preparing concentrated ammonia water with a concentration of 38%-42% by using an ammonia water preparation unit; (2) adding p-nitrochlorobenzene, concentrated ammonia water and an additive into a reaction kettle, and then carrying out heat preservation reaction under the condition of 150-170 DEG C and 5.6-6.2 MPa for 14-16 h; the additive comprises modified cyclodextrin and trehalose; (3) after pressure relief, the materials in the reaction kettle are transferred into a water washing kettle to carry out water washing and stirring for 1-2 h, and the material liquid after water washing is subjected to centrifugal separation to obtain p-nitroaniline. According to the synthesis process, the modified cyclodextrin and the trehalose are compounded and synergized, the balance problem of the main reaction efficiency and the side reaction inhibition is solved from the reaction mechanism level, and finally the high yield and the high purity in the synthesis process of p-nitroaniline are simultaneously achieved.

The invention relates to the technical field of solar cells, and particularly discloses a polishing additive for solving the problem of white spots in the pre-rough polishing process of a BC battery and a using method.The polishing additive is prepared from, by weight, 1.0%-10.0% of accelerant, 0.1%-5% of defoaming agent, 0.1%-0.5% of pH regulator, 0.01%-0.1% of surfactant and the balance deionized water; the accelerant is selected from one or a combination of more than two of sodium p-toluenesulfonate, perbenzoic acid, 2-nitroaniline, parachloronitrobenzene and sodium 2-methoxy-5-nitrophenolate; the accelerant is one or a combination of more than two of sodium p-toluenesulfonate, perbenzoic acid, 2-nitroaniline, parachloronitrobenzene and sodium 2-methoxy-5-nitrophenolate; by adopting an alcohol-free and phosphorus-free environment-friendly component design, the polishing additive obviously reduces the difficulty of subsequent sewage treatment while ensuring the efficient polishing performance, avoids the pollution of a traditional alcohol-containing and phosphorus-containing additive to the environment, effectively solves the problem that a silicon wafer is easy to generate white spots after a previous rough polishing process, and also has the advantages of simple process and low cost. And through an optimized surfactant and defoaming agent compounding technology, the surface flatness of the silicon wafer is further improved, and double breakthrough of environmental protection and performance is realized.

The invention relates to a preparation method of 2 ', 4-dichloro-2-aminodiphenyl ether, and belongs to the technical field of chemical synthesis. The preparation method comprises the following steps: S1, carrying out selective hydrogenation reaction on m-dinitrobenzene to prepare m-nitroaniline; s2, in a solvent, the m-nitroaniline and the N-chlorosuccinimide are subjected to a reaction, and 2-chloro-5-nitroaniline is prepared; s3, carrying out a co-thermal reaction on the 2-chloro-5-nitroaniline, o-nitrophenol, an alkali and a solvent to prepare 2 ', 4-dinitro-2-aminodiphenyl ether; s4, dissolving the 2 ', 4-dinitro-2-aminodiphenyl ether in a solvent, adding a FeCl3 solution, sodium chloride and Oxone, and performing catalytic reaction under the ultraviolet light condition to prepare the 2', 4-dichloro-2-aminodiphenyl ether.The preparation method has the advantages that raw materials are easy to obtain, the reaction effect is good, few three wastes are generated, the reaction is cleaner and greener, the conversion rate is high, and the 2 ', 4-dichloro-2-aminodiphenyl ether is suitable for industrial application.