38 results about "P-Nitroaniline" patented technology

The invention discloses a method for continuously and efficiently synthesizing N-methyl p-nitroaniline, which comprises the following steps: S1, preparing a 1-fluoro-4-nitrobenzene solution by using an organic solvent, stirring and dissolving, filtering to remove impurities, and transferring to a container A for heat preservation; s2, preparing a methylamine solution by using an organic solvent, adding a preferred catalyst, controlling the temperature at 25-50 DEG C, and transferring the prepared solution into a container B for heat preservation; s3, exhausting by using an organic solvent, ensuring that no bubbles exist in the micro-mixer and the continuous flow reactor, introducing the material into the continuous flow reactor from the container A and the container B according to a certain proportion through the micro-mixer by using a delivery pump, and adjusting the temperature and pressure in the reactor for reaction to obtain a reaction solution; and S4, after the reaction liquid flows out, collecting the reaction liquid in a container C, filtering the collected reaction liquid, washing with an organic solvent, and drying to obtain a crude product N-methyl p-nitroaniline. The problems of high safety risk, tedious steps, long reaction time and the like of an intermittent kettle type process are effectively solved.

The invention discloses a synthesis method of sulfachloropyrimidine, which comprises the following steps: taking paranitroaniline and 4, 6-dichloropyrimidine as raw materials, synthesizing acyl chloride by diazotization and sulfonylation of paranitroaniline, generating aminopyrimidine by ammonification of 4, 6-dichloropyrimidine, condensing aminopyrimidine and acyl chloride, and then synthesizing sulfachloropyrimidine by reduction. According to the method, chlorosulfonic acid is not used in the reaction process, the reaction treatment is simple, and the safety risk is reduced. Acid used in the chlorosulfonation process and ammonia used in the ammonification process can be recycled and reused, the product yield reaches 76.2%, and the quality meets the standard requirement. The process can improve the yield and reduce the production cost, the production process is easy to control, less three wastes are generated, and the environmental pollution is small.

The invention relates to an atestin diterpenoid compound as well as a preparation method and application thereof, and belongs to the technical field of medicinal chemistry. The preparation method of the atestin diterpenoid compound comprises the following steps: S1, taking commercially available paranitroaniline 1a as a raw material to obtain an intermediate 2a; carrying out amide condensation and reduction on the intermediate 2a and corresponding amine to obtain intermediates 4a-4c; s2, taking commercially available m-nitrophenol 1d as a raw material to obtain an intermediate 3d; s3, taking commercially available 1-(t-butyloxycarbonyl) piperidine-3-carboxylic acid 1e as a raw material to obtain an intermediate 3e; s4, taking a compound J10 separated from a natural plant sea lacquer as a raw material to obtain compounds HXY1-6; and S5, taking a compound J12 separated from a natural plant sea lacquer as a raw material to obtain compounds HXY7-23. The invention aims to explore a preferable compound with a novel structure, better activity and high safety through structural optimization of a natural product, and provides support for research and development of a novel sEH inhibitor and an anti-AD drug.

The invention belongs to the technical field of chemical synthesis, and provides a high-purity 2, 6-dichloro-4-aminophenol synthesis method, which comprises: A1, mixing paranitroaniline and a 20-35 wt% hydrochloric acid aqueous solution, heating, introducing chlorine gas, and carrying out a reaction to obtain 2, 6-dichloro-4-nitroaniline; a2, mixing the 2, 6-dichloro-4-nitroaniline with methylbenzene, so as to obtain a 2, 6-dichloro-4-nitroaniline solution; mixing sulfuric acid, purified water and a first catalyst to obtain liquid; a3, sulfuric acid and nitrososulfuric acid are mixed and cooled, a 2, 6-dichloro-4-nitroaniline solution is dropwise added, a diazonium solution is obtained, the temperature is increased, the diazonium solution is dropwise added into the liquid, and a 2, 6-dichloro-4-nitrophenol phase is obtained; and A4, adding the 2, 6-dichloro-4-nitrophenol, toluene and a second catalyst into the reaction kettle, introducing hydrogen, and carrying out hydrogenation reaction to obtain the 2, 6-dichloro-4-aminophenol. The synthesis method disclosed by the invention is simple, the used second catalyst can be recycled, the generation amount of three wastes is small, and the yield and the purity of the 2, 6-dichloro-4-aminophenol are high.

The present application relates to the technical field of medicine, and provides a potency calibration method of haena polysaccharide.The present application adopts p-nitroaniline colorimetric method to test the haena polysaccharide activity curve, wherein the abscissa of the haena polysaccharide activity curve is the reciprocal of the weight of haena polysaccharide, and the ordinate is the logarithm of the residual activity unit of FVIII; the weight of haena polysaccharide for inhibiting the iFXase (endogenous factor X enzyme) activity of 1 IU FVIII is taken as 1 potency unit, and the potency of haena polysaccharide is obtained according to the haena polysaccharide activity curve.The potency calibration method provided by the present application can accurately calibrate the anticoagulant activity intensity of haena polysaccharide, and has important significance in aspects of guaranteeing drug efficacy, drug safety and quality control.

The invention relates to the technical field of biochemical engineering, in particular to paranitroaniline hydrophobic haptens as well as a preparation method and application thereof. Specifically, on the basis of paranitroaniline, the hydrophobicity of a target object is adjusted by introducing a polar atom (F, N or O) from a spacer arm. And then coupling the hapten with a carrier protein, and evaluating the immunogenicity of the artificial antigen. The invention explores the influence of hapten hydrophobic change on immunogenicity, on one hand, theoretical support is provided for reasonable design of hapten; on the other hand, a material basis is provided for preparing a high-affinity antibody of paranitroaniline. The invention provides a new thought for reasonable design of small molecule compound hapten and preparation of high-affinity antibody.

The present invention provides a preparation method of a triazine derivative. The preparation method comprises the following steps: subjecting p-nitroaniline to a substitution reaction with compound A to form intermediate B; and subjecting intermediate B to a hydrogenation reduction alkylation reaction with compound C to obtain the triazine derivative. The above method provided by the present invention prepares the triazine derivative by a two-step method of substitution first and then hydrogenation reduction alkylation, which not only has a high product yield, but also greatly shortens the process flow. At the same time, this method effectively avoids the generation of by-products of disubstituted p-phenylenediamine in the traditional process, makes the product separation easy, greatly reduces the cost, has no pollution, has high product quality, and is easy to realize industrialization.

The present application discloses a method for continuously and efficiently synthesizing N-methyl-p-nitroaniline, comprising the following steps: S1, using an organic solvent to prepare 1-fluoro-4-nitrobenzene solution, stirring and dissolving, filtering and removing impurities, transferring to container A for insulation; S2, using an organic solvent to prepare methylamine solution, adding a preferred catalyst, controlling the temperature at 25 DEG C-50 DEG C, transferring the prepared solution to container B for insulation; S3, using an organic solvent to exhaust, ensuring that there is no bubble in micro mixer and continuous flow reactor, utilizing a transfer pump to introduce material from container A and container B into continuous flow reactor in a certain ratio through a micro mixer, regulating the temperature and pressure in the reactor for reaction to obtain a reaction solution; S4, after the reaction solution flows out, it is collected in container C, the collected reaction solution is filtered, washed with an organic solvent, and dried to obtain a crude product N-methyl-p-nitroaniline. The present application effectively solves the problems of high safety risk of intermittent kettle process, complicated steps, and long reaction time.

The utility model relates to the technical field of paranitroaniline production, and discloses a micro-channel reactor for producing paranitroaniline, which comprises a reaction kettle, a cleaning mechanism is arranged outside the reaction kettle, a heating mechanism is arranged on the inner side of the reaction kettle, the cleaning mechanism comprises a connecting ring, and the connecting ring is connected with the heating mechanism. A connecting column is fixedly connected to one end of the connecting ring, a cleaning ring is fixedly connected to one end of the connecting column, a connecting hole is formed in the outer portion of the cleaning ring, a cleaning rod is inserted into the inner side of the connecting hole, a cleaning brush is fixedly connected to one end of the cleaning rod, and a fixing assembly is arranged at one end of the cleaning rod. According to the micro-channel reactor for producing the paranitroaniline, the inner wall of the reaction kettle is cleaned through the cleaning mechanism, the influence on the reaction effect of the paranitroaniline is avoided, rapid and uniform heating can be performed through the heating mechanism, and the reaction effect of the paranitroaniline is improved. Therefore, cleaning and heating operations are completed.

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 present application relates to papermaking technical field, especially to a kind of anti-myopia yellow light absorption dye preparation method and myopia protection paper.The present application discloses a kind of anti-myopia yellow light absorption dye preparation method, dye preparation is diazotized to p-nitroaniline, coupled with 2-(2-hydroxy-5-sulfonic acid group phenyl) benzotriazole, salting-out, then with zinc sulfate, sodium sulfide complex azo dye-zinc sulfide complex is obtained.The protection paper is made by 3D printing texture forming and multiple composite function layer, mixed dye, 3D printing net form paper is made of pulp;Coated with bottom layer composite fluid, spray nano-silicon dioxide to obtain first-stage processing paper;Pretreatment dye coating, crosslinking to obtain secondary processing paper;Hot-pressing copolymerization fiber membrane and fumigation are obtained.The paper can prevent myopia, and is suitable for writing and printing.

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 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 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 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.

A method for purifying p-nitroaniline and application thereof, comprising the following steps: (1) dissolving: adding p-nitroaniline into an oxygen-containing polar solvent, and stirring until completely dissolved; (2) filtering: adding a filter aid into the above solution, and filtering, wherein the filter cake is tar impurities in the p-nitroaniline and the filter aid, and the filtrate is the purified p-nitroaniline solution; (3) post-treatment: adding water to the purified p-nitroaniline solution to perform rectification, wherein the solvent is collected at the top of the column, and is recycled and reused; the suspension of water and p-nitroaniline is collected at the bottom of the column, and is filtered, wherein the filter cake is the purified p-nitroaniline, and the filtrate is water, which is recycled and reused. The p-nitroaniline treated by the method has a bright yellow appearance, a small odor and no pungent smell, and can be directly used for catalytic hydrogenation reaction, especially the reaction of a noble metal catalyst, so that the catalyst can be continuously recycled, and the product quality meets the standards.

The invention discloses a multichannel fluorescent probe compound based on pyrone functionalization. The compound is synthesized through the steps of diazotization, cyclization, condensation and the like of raw materials such as paranitroaniline, furaldehyde, 2-hydroxy-1-naphthaldehyde and the like. Q3 has high selective recognition capability on Cu, and in a DMSO / HEPES buffer solution, Cu can enable fluorescence of a probe solution to be quenched, ultraviolet absorption to be subjected to red shift and the color to be changed from light green to yellow, so that fluorescence and naked eye detection are realized; the formed Q3-Cu complex can specifically recognize CN, so that fluorescence recovery, ultraviolet absorption blue shift and turning of color back to light green are caused, and Cu and CN can be continuously detected. The probe can be used for Cu / CN fluorescence imaging in living cells, detection of Cu residues in traditional Chinese medicinal materials and preparation of Cu / CN detection test paper, and has the characteristics of high sensitivity, strong anti-interference performance, quick response and the like.

The present application relates to the technical field of organic synthesis, in particular to a preparation method of N-(4-nitrophenyl)-4-nitrobenzamide, which comprises the following steps: S1, dissolving p-nitrobenzoyl chloride in an inert compound solvent under the condition of inert gas; the inert compound solvent comprises an aprotic main solvent and a weak polar cosolvent; S2, controlling the temperature and slowly adding part of p-nitroaniline in the system of step S1 to form a seed reaction liquid after mixing; S3, slowly adding the remaining part of p-nitroaniline in the seed reaction liquid of step S2 and heating and incubating for reaction; S4, after the reaction is completed, N-(4-nitrophenyl)-4-nitrobenzamide is obtained through post-treatment. In the preparation process, no additional catalyst is needed, the side reaction can be effectively inhibited, the safety and stability of the production process are ensured, the product yield and purity are significantly improved, and the method is more suitable for industrial application.

The invention discloses an anti-mildew antibacterial PVC printing film and a preparation method thereof, and relates to the technical field of printing films. When the anti-mildew and antibacterial PVC printing film is prepared, firstly, polyvinyl chloride reacts with paranitroaniline, a palladium-carbon catalyst is used for reduction, then the product reacts with 2, 3-bis (4-chlorphenyl)-2-cyclopropylene-1-ketone, then the product reacts with polyether amine, and modified polyvinyl chloride is obtained; secondly, enabling talcum powder pretreated by p-(triethoxysilyl) acetophenone to react with methyl tribenzoate phosphine to obtain modified talcum powder; finally, the modified polyvinyl chloride, the modified talcum powder and sodium methoxide are mixed and subjected to film casting, and the anti-mildew and antibacterial PVC printing film is prepared. The anti-mildew and antibacterial PVC printing film prepared by the invention has good flame retardance, mildew-proof and antibacterial properties, mechanical properties and ultraviolet aging resistance.

The present application relates to a kind of synthesis method of L-gamma-glutamyl-p-nitroaniline, mainly solve the technical problem that the yield of prior art method is low, difficult to purify, cannot scale production.The synthesis method includes the following steps: first, p-nitroaniline and phosphorus trichloride, reaction is generated in pyridine N,N'-bis (4-nitrophenyl) phosphorimidate amide, then and Boc-L-Glu-OtBu dissolved in DMF continue to react, after treatment, obtain intermediate N-Boc-L-Glu (PNA)-OtBu (crude product).Second step, intermediate N-Boc-L-Glu (PNA)-OtBu (crude product) is reacted in dichloromethane and trifluoroacetic acid solution, then concentrated, tap water is added to the residue, in turn with potassium carbonate solution neutralization, filtration, the obtained filter cake is backwashed with methanol, after filtration, drying obtains target product L-gamma-glutamyl-p-nitroaniline, purity is greater than 99%.

The utility model relates to the technical field of nitroaniline, and discloses a continuous amination reaction device of p-nitroaniline, which comprises a reaction kettle, a motor is arranged on the side wall of the reaction kettle, a rotating shaft is rotatably connected in the reaction kettle, the output end of the motor is connected with the rotating shaft, a cleaning assembly is arranged in the reaction kettle, and the cleaning assembly is connected with the rotating shaft. A first stirring blade is fixedly connected to the side wall of the rotating shaft, a second stirring blade is fixedly connected to the side wall of the rotating shaft, and a filtering assembly is arranged on the side wall of the reaction kettle; the cleaning assembly comprises a connecting frame. According to the reaction kettle, water is pumped from the water tank to the connecting pipe and the conveying pipe through the fixed pipe by starting the water pump and is sprayed out through the spray head, and meanwhile, the motor is started to drive the rotating shaft, so that the connecting frame and the cleaning brush on the side wall of the connecting frame clean the inner wall of the reaction kettle under the cooperation of the telescopic rod and the spring, and the stirring blade I and the stirring blade II are also cleaned in water when the rotating shaft rotates; the problems that the cleaning mode is single and comprehensive cleaning is difficult are solved.

The invention discloses an apixaban intermediate 5, 6-dihydro-3-(4-morpholinyl)-1-(4-nitrophenyl)-2 (1H)-piperidone and a synthesis method thereof, and relates to the technical field of synthesis of medical intermediates.The preparation method comprises the following steps that paranitroaniline is dissolved in chlorobenzene, organic alkali and pentachlorovaleryl chloride are added, a reaction is performed for 2-4 hours, and a mixture is obtained; after paranitroaniline is reacted, sodium hydroxide is added for continuous reaction, and then water is added for treatment to obtain 1-(4-nitrophenyl)-2-piperidone; adding phosphorus pentachloride until the reaction of the 1-(4-nitrophenyl)-2-piperidone is finished, and then adding water for treatment to obtain 3, 3-dichloro-1-(4-nitrophenyl)-2-piperidone; and after the reaction is finished, removing the solvent to obtain the 5, 6-dihydro-3-(4-morpholinyl)-1-(4-nitrophenyl)-2 (1H)-piperidone. The industrial operation is simplified, and the cost is saved.

The invention relates to the technical field of chemical production and discloses a preparation device and process applied to paranitroaniline production, the preparation device applied to paranitroaniline production comprises a base, a shell assembly and an inner container assembly, the shell assembly and the inner container assembly are fixedly installed at the top of the base, and the inner container assembly is arranged in the shell assembly; the inner container assembly comprises a corrosion-resistant inner container fixedly installed at the top of the base, the inner wall of the corrosion-resistant inner container is rotationally connected with a stirring shaft, a heat transfer mechanism is arranged in the corrosion-resistant inner container, and through the arranged extension assembly, the stirring shaft is rotated anticlockwise at the moment when heat is released violently in the initial stage of the reaction, and the heat transfer mechanism is arranged in the corrosion-resistant inner container; the stirring shaft drives the driving frame to rotate through the connecting rod, and the driving frame drives the extension bag to unfold and pulls the fixing frame; after the extension bag is unfolded, the heat dissipation area is obviously enlarged, a large amount of heat generated by reaction can be effectively dissipated, local overheating is avoided, and the product quality and the production safety are guaranteed.

The invention discloses a stable paranitroaniline diazonium salt synthesis method, which comprises: washing a sulfonic acid resin with deionized water, adding into a reaction kettle, preparing a certain amount of deionized water, adding into the reaction kettle, starting stirring, and uniformly mixing; then slowly adding paranitroaniline into the reaction kettle for multiple times for dissolving, uniformly stirring until no obvious solid residues exist on the liquid surface, setting the temperature, injecting a fresh sodium nitrite solution into the reaction kettle, and after the reaction is finished, filtering, washing and drying the mixture. And adding the obtained diazonium salt into deionized water and carrying out substitution reaction with quantitative potassium iodide to obtain 4-nitroiodobenzene to indirectly calculate the yield. The diazonium salt is subjected to an ARC thermal stability test to prove that the diazonium salt is relatively good in thermal stability and can be stored for a relatively long time at room temperature.

The invention discloses a tail gas absorption device in the production process of paranitroaniline, and the tail gas absorption device in the production process of paranitroaniline comprises a fixed bottom plate, a tail gas conveying assembly, a solution supplementing assembly and an automatic stirring assembly. In order to solve the problem that the absorption efficiency of the subsequent nitroaniline is reduced due to the fact that the solution is gradually saturated when the tail gas is subjected to absorption treatment, a solution supplementing assembly is designed, nitroaniline wastewater can be automatically and continuously output and purified water can be automatically and continuously supplemented through the solution supplementing assembly when the tail gas is subjected to absorption treatment; therefore, the problem that the absorption efficiency is reduced due to the fact that the solution is saturated after being absorbed for a long time is effectively avoided, the beneficial effect of automatic supplementing is achieved, further, the automatic stirring assembly is designed, hot water is continuously stirred through the arrangement of the automatic stirring assembly, and the water temperature is made to be uniform.