44 results about "Nitrochlorobenzene" patented technology

The invention belongs to the technical field of optical drive catalytic materials, and discloses a preparation method of a foamed ceramic-metal organic framework composite catalytic material and application of the foamed ceramic-metal organic framework composite catalytic material in photo-thermal catalytic elimination of nitro compounds. According to the invention, photo-thermal catalytic MOFs are loaded on foamed ceramic, and a floatable integrated photocatalytic material is formed through in-situ self-assembly and is used for solar-driven nitro-compound thermal elimination. MOFs have high specific surface area, high porosity, good light absorption and high photo-thermal conversion efficiency; the foamed ceramic has the characteristics of strong adsorbability, good heat conduction, light weight, adjustable size and the like. The combination of the two overcomes the problems of difficult recovery, more residues and low efficiency of the traditional powder catalyst and the high cost, high energy consumption, high-temperature danger and the like of the traditional photo-thermal catalysis, and shows huge application potential. The method can be used for treating organic wastewater containing toxic nitro compounds (such as trinitrotoluene, dinitrobenzene, nitrochlorobenzene and the like), and a new thought is provided for wastewater treatment in the fields of explosives, medicines, pesticides, dyes and the like.

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

The invention discloses a 96-hole preassembled plate fat-soluble vitamin pretreatment kit, and belongs to the technical field of in-vitro diagnostic reagents. Comprising magnetic bead suspension liquid, equilibrium liquid, leacheate 1, leacheate 2 and eluent which are carried on a preassembled plate, and the magnetic bead suspension liquid comprises absolute ethyl alcohol and magnetic beads; the preparation process of the magnetic beads comprises the following steps: activating carboxyl of the carboxyl magnetic beads through EDC and NHS; then nitrochlorobenzene and triethylamine are added for a coupling reaction; mixing the coupling reaction product with pyrrolidone, ammonium persulfate and a pore-foaming agent to obtain target magnetic beads; the magnetic beads can be specifically combined with fat-soluble vitamins in human serum or plasma, efficient separation and release of an object to be detected are achieved through a magnetic separation technology, and the magnetic beads are suitable for follow-up mass spectrum quantitative analysis. The kit disclosed by the invention has the characteristics of simplicity and convenience in operation, high extraction efficiency and good stability, the pretreatment time can be remarkably shortened, the detection accuracy is improved, and an efficient solution is provided for clinical detection of fat-soluble vitamins.

The present invention relates to the technical field of fine chemical synthesis, and particularly discloses a continuous ammonolysis method for mixed nitrochlorobenzene. The continuous ammonolysis method for mixed nitrochlorobenzene is characterized in that: the mixed nitrochlorobenzene is continuously added to the primary ammonolysis kettle, and is mixed countercurrently with ammonia water and a catalyst from the subsequent ammonolysis kettle to carry out an ammonolysis reaction. The reaction liquid enters the separator at the upper part of the kettle through a lift. A part of the liquid material is refluxed into the reaction zone at the lower part of the kettle, and after the organic phase and the ammonia water phase are separated in the separator for the other part of the liquid material, the organic phase flows into the subsequent ammonolysis kettle to continue the ammonolysis reaction; until the reaction and separation are completed in the last ammonolysis kettle to obtain a crude product of mixed nitroaniline, which enters the refining section for refining. The present invention can reduce the consumption and circulation amount of concentrated ammonia water, realize the efficient conversion of mixed nitrochlorobenzene under relatively mild reaction conditions, effectively inhibit side reactions such as hydrolysis and coking, and at the same time reduce material consumption and energy consumption, and increase the economy of the reaction.

This utility model discloses an apparatus for preparing 2,4,4'-trichloro-2'-nitrodiphenyl ether, relating to the technical field of 2,4,4'-trichloro-2'-nitrodiphenyl ether production apparatus. The inlet of the reaction vessel is connected via pipelines to a 2,4-dichlorophenol tank, a 2-nitro-4-chlorophenol tank, a sodium hydroxide tank, and an N,N-dimethylformamide tank. The outlet of the reaction vessel is connected via pipelines to an extraction tank. The inlet of the extraction tank is connected via pipelines to a deionized water tank and an ethyl acetate tank. The outlet of the extraction tank is connected via pipelines to an organic phase tank. The outlet of the organic phase tank is connected via pipelines to a drying tank. The inlet of the drying tank is connected via pipelines to an anhydrous sodium sulfate tank. The outlet of the drying tank is connected via pipelines to a vacuum distillation tank. The bottom outlet of the vacuum distillation tank is connected via pipelines to a product tank. The process is simple, and the product yield and purity are high.

The present application relates to the technical field of chemical production, and discloses a method and device system for continuously producing nitrochlorobenzene and application thereof. In the method, mixing of reaction raw materials and reaction are completed in steps, so that the defect of too severe heat release, too high temperature, side reaction and safety problem caused by direct reaction is avoided. Meanwhile, by controlling the volume flow ratio of nitric acid and chlorobenzene feed, the raw material conversion rate and the yield of the target product are improved, and the proportion of p-nitrochlorobenzene in the product is also increased, so that the economic benefit is improved. In addition, the method provided by the present application does not need concentrated sulfuric acid as a catalyst, so that the problem of difficult treatment of waste sulfuric acid is solved, and the environmental protection of nitrochlorobenzene production is improved.

The application discloses a high-energy-density compound based on polynitrobenzene-linked pyrazole and a synthesis method thereof. The high-energy-density compound based on polynitrobenzene-linked pyrazole is 4-nitro-1-(2,4,6-trinitrobenzene)-pyrazole-3,5-diamine or 4-nitro-N 5 -(2,4,6-trinitrophenyl)-1H-pyrazole-3,5-diamine, which is prepared from 2,4,6-trinitrochlorobenzene and 3,5-diamino-4-nitropyrazole under the condition that N,N-dimethylformamide is used as an alkali to occur nucleophilic substitution reaction. The preparation method is simple, the reaction steps are few, the separation method is simple, and the prepared product has good energy performance and stability.

This invention discloses a tail gas recovery device for nitrochlorobenzene production, relating to the field of nitrochlorobenzene production technology. It includes a treatment chamber with an inlet pipe connected to one side of its bottom and an exhaust pipe connected to its top. A piston plate is installed inside the treatment chamber, and an electric telescopic rod is connected to one side of the chamber. A first lifting rod is connected to the telescopic end of the electric telescopic rod and is connected to the piston plate. Multiple atomizing nozzles are distributed laterally at equal intervals on the bottom of the piston plate. The tail gas generated during nitrochlorobenzene processing enters the treatment chamber through the inlet pipe. The atomizing nozzles on the piston plate spray the tail gas with a reaction liquid, facilitating the elimination of harmful substances in the tail gas. During this process, the piston plate also descends, compressing the tail gas and atomized liquid within the treatment chamber, ensuring sufficient contact and reaction within a smaller space, thereby improving the treatment effect.

This invention relates to the field of pharmaceutical intermediate synthesis technology, and discloses a preparation process for diaminophenoxyethanol sulfate, comprising the following steps: Step S1, preparing chitosan-supported nickel nanoparticles: using chelated cross-linked chitosan microspheres to chelate nickel salt, and then adding a reducing agent to reduce nickel ions to obtain chitosan-supported nickel nanoparticles; Step S2, using 2,4-dinitrochlorobenzene and ethylene glycol as raw materials, synthesizing 2,4-dinitrophenoxyethanol under the action of an alkaline catalyst; Step S3, using 2,4-dinitrophenoxyethanol as raw material and 1,4-dioxane as solvent, the prepared chitosan-supported nickel nanoparticles have a higher loading capacity for nickel nanoparticles. As a catalyst, in the process of catalyzing the hydrogenation of 2,4-dinitrophenoxyethanol to prepare 2,4-diaminophenoxyethanol, the nickel nanoparticles are not prone to agglomeration, and after repeated use, they still maintain good catalytic activity and excellent stability.

The invention belongs to the technical field of organic synthesis and fine chemical engineering, and particularly relates to a method for continuously synthesizing 2, 5-dimethoxy-4-nitrochlorobenzene. A continuous flow reaction system is adopted, 2, 5-dimethoxychlorobenzene and 75%-78% nitric acid are pumped into the system respectively, mixed and then enter a silicon carbide microchannel reactor, an initial reaction is carried out at the temperature of 40-60 DEG C, then the mixture enters a coil delay microreactor at the temperature of 50-70 DEG C to complete nitration, and the total retention time is 20-80 seconds. According to the method disclosed by the invention, accurate temperature control on the strong exothermic nitration reaction is realized through enhanced mixing and heat transfer of the microreactor, concentrated sulfuric acid does not need to be added, the reaction can be completed within tens of seconds, the raw material conversion rate is high (the residue is less than or equal to 0.13%), the product selectivity is good (the content is more than or equal to 98.33%), and the production efficiency and the process safety are remarkably improved; the method is suitable for green, efficient and continuous production of the intermediate, realizes accurate monitoring, and is suitable for large-scale safe production.

The present application relates to the synthesis of pesticide compounds, in particular to a method for preparing a pyrasulfotole intermediate. The method comprises: (1) using p-chlorotoluene as a raw material, through nitration, chlorination, hydrolysis, or chlorination, hydrolysis, nitration, to obtain 3-nitro-4-chlorobenzaldehyde, (2) fluorination and reduction of 3-nitro-4-chlorobenzaldehyde to obtain 4-fluoro-3-amino benzaldehyde; (3) 4-fluoro-3-amino benzaldehyde is then contacted with chloroformate for reaction, and then chlorination to obtain compound IV; (4) compound IV is contacted with trifluorobutanamine ester under alkaline conditions for reaction to obtain compound I. The process for preparing compound I avoids using expensive raw material 2-chloro-4-fluorobenzoic acid, effectively reduces the cost of raw materials, reduces the three wastes generated in the process, and at the same time, the total yield of the reaction is high, and it is suitable for industrial mass production.

The present invention provides a method for recovering and treating a 4,4-dinitrodiphenyl ether by-product, and belongs to the technical field of organic synthesis. The present invention adjusts the pH value to 3-4 to remove substances that can react with acid in the by-product salt, and the functions of ferrous sulfate and the first activated carbon are to decolorize and remove the color of the 4,4-dinitrodiphenyl ether material. The pH value is then adjusted to 6-8 to remove ferrous sulfate, and then a second decolorization is performed to obtain a white solid salt. The function of hydrogen peroxide is to remove organic matter in the reaction, and the resin column elution ensures that p-chloronitrobenzene, sodium p-nitrophenolate, and DNP organic matter are completely removed. Finally, a solid salt having a sodium chloride content of ≥99.1g / 100g and a TOC (total organic carbon) of less than 50mg / kg is obtained. The obtained solid salt does not have the odor of p-nitrochlorobenzene, meets the industrial salt standard, and realizes the recovery and use of the 4,4-dinitrodiphenyl ether by-product, thereby reducing costs.

The application discloses a method for synthesizing 2,4-dinitroanisole based on a channel type continuous flow. The method uses a methanol solution of 2,4-dinitrochlorobenzene as a first mixed solution, an aqueous sodium hydroxide solution as a second mixed solution, then controls parameters of a micro-channel reactor, pumps the first mixed solution and the second mixed solution into the micro-channel reactor for mixing and reaction, finally cools and collects the mixed solution by using ice water, and filters and dries to obtain 2,4-dinitroanisole. In the method, the conversion rate of 2,4-dinitrochlorobenzene is high, the yield of 2,4-dinitroanisole is high, the quality of 2,4-dinitroanisole is high, the synthesis process is environmentally friendly, and safety is good.

The invention relates to the technical field of chemical products, in particular to preparation and application of polysubstituted phenol intermediates, and discloses a green preparation method of polysubstituted phenol intermediates (such as p-nitrophenol and 2, 4-dinitrophenol), the core is that a chitosan-montmorillonite composite carrier is used for loading a nano zero-valent iron catalyst, and the nano zero-valent iron catalyst is used for preparing the polysubstituted phenol intermediates (such as p-nitrophenol and 2, 4-dinitrophenol). Efficient synthesis is realized through a normal-temperature and normal-pressure hydrolysis-reduction one-step method. The cost of the catalyst is reduced by 60% compared with that of the traditional supported catalyst, and the yield is still kept at 88.8% after the catalyst is repeatedly used for five times; by adding the dispersing agent, the substrate-catalyst contact area is increased, and the p-nitrochlorobenzene is high in conversion rate, high in yield and high in purity; by adopting a normal-temperature and normal-pressure process, the energy consumption is reduced by 40% compared with that of a high-temperature hydrogenation method, and the COD (Chemical Oxygen Demand) The method is suitable for the fields of medicines, pesticides, materials and the like, solves the problems of expensive catalyst, harsh conditions and heavy pollution in the prior art, and has a wide industrial prospect.

The application discloses a wastewater treatment method for nitrochlorobenzene production and belongs to the technical field of organic chemical wastewater treatment. The treatment method comprises the following steps: wastewater is self-flowed into a pretreatment tank and is layered by standing, upper-layer wastewater is treated by using adsorption resin to obtain desorption liquid, catalyst and potassium persulfate are added into the desorption liquid, stirring and filtering are carried out, and treatment liquid is obtained, and the treatment liquid is discharged after being detected to be qualified. In the application, sulfate radicals are used as main active molecules to treat phenolic substances. In order to improve the treatment efficiency, the application prepares a catalyst. The catalyst prepared by the application is prepared by loading active substances on a carrier. The carrier is a diatomite-based carrier with high porosity and strong catalytic performance. The main component of the active substances is magnetic nano CoFe2O4 particles. The wastewater treatment method for nitrochlorobenzene production disclosed by the application can significantly reduce the content of nitrochlorobenzene and the total phenol content in wastewater.

The invention relates to an industrial method for continuous high-efficiency catalytic synthesis of m-nitroaniline, which comprises the following steps: preparing a m-nitrochlorobenzene solution, fully mixing the m-nitrochlorobenzene solution and a concentrated ammonia water solution in a mixer, preheating in a preheater after mixing, passing through a fixed bed dynamic tubular reactor, and carrying out continuous high-efficiency catalytic synthesis of m-nitroaniline. Reacting in a dynamic tubular reactor under the catalysis of a fixed bed catalyst, cooling in a cooling kettle for gas-liquid separation, and elutriating and filtering in an elutriating kettle to obtain a final product. The process safety risk can be remarkably reduced, the reaction period is greatly shortened, the process operation is simple and convenient to regulate and control, and the process stability is high.

The application discloses a treatment process of p-nitrochlorobenzene wastewater and belongs to the technical field of wastewater treatment. The treatment process comprises the following steps: in the first step, the p-nitrochlorobenzene wastewater is introduced into a composite oxidation tank, the pH of the p-nitrochlorobenzene wastewater is adjusted to 5-6, a functional additive and a persulfate salt are added into the composite oxidation tank, and stirring is carried out for 3-4 hours to obtain oxidation wastewater; and in the second step, the oxidation wastewater is filtered, the filtrate is discharged after detection, and the filtrate that does not reach the qualified standard is introduced into the composite oxidation tank for cyclic treatment. The functional additive is a (3-carboxylpropyl) triphenylphosphonium bromide modified zeolite loaded with Pd / Fe. In view of the problem that the p-nitrochlorobenzene is difficult to be directly oxidized and degraded, the p-nitrochlorobenzene is reduced into an amine intermediate product that is easy to be degraded by introducing the functional additive, and then the amine intermediate product is oxidized and degraded by using the persulfate salt, so that the content of the p-nitrochlorobenzene in the wastewater is effectively reduced.

The invention discloses a preparation method of high-purity p-nitrochlorobenzene, and belongs to the technical field of chemical raw materials. The preparation method comprises the following steps: S1, adding chlorobenzene, nitric acid and a catalyst into a synthesis kettle for reaction, and obtaining a mixed product after the reaction is completed; s2, the mixed product is cooled and pumped into a plate-and-frame filter press for solid-liquid separation, a nitrate oil phase is separated out, the nitrate oil phase is neutralized, washed with water, dried and crystallized, and high-purity p-nitrochlorobenzene is obtained. According to the method, the target of efficiently preparing the high-purity p-nitrochlorobenzene is achieved through functional adaptation and process synergy of all the steps, the solid catalyst is adopted, catalytic sites are concentrated, and high catalytic efficiency can be achieved by adding a small amount of the solid catalyst.

The invention discloses a photocatalytic oxidation combined treatment process and device for nitrochlorobenzene wastewater, and the process comprises the following steps: continuously feeding nitrochlorobenzene wastewater into a first-stage synergistic catalysis system, introducing ozone and hydrogen peroxide, and carrying out a synergistic oxidation reaction to obtain first-stage oxidized effluent; and continuously adding primary oxidation effluent into a secondary photocatalytic oxidation system, adding hydrogen peroxide, and carrying out an oxidation reaction under co-catalysis of ultraviolet light and a photocatalyst. The chromaticity of the wastewater is reduced to 500-1000 times by adopting ozone / hydrogen peroxide concerted catalysis, then the wastewater is connected with a subsequent improved secondary photocatalytic oxidation system for photocatalytic oxidation, and meanwhile, a thin wire is wound on an ultraviolet lamp sleeve with relatively high light intensity, so that turbulent flow near the sleeve can be enhanced, and more wastewater enters a strong ultraviolet light area; the photocatalyst is arranged on the reactor wall with relatively weak light intensity, so that the oxidation capacity of a weak ultraviolet region can be enhanced, the treatment capacity of the tubular reactor is improved, the treatment time is shortened, and the treatment cost is saved.

This invention provides a method for treating nitrochlorobenzene tar by catalytic hydrogenation to obtain aniline compounds containing chloroaniline and chlorodiphenylamine. This invention utilizes low-value production wastewater to produce chloroaniline and chlorodiphenylamine, which have higher economic value, thus solving the problems of high safety risks and low recovery rates in existing nitrochlorobenzene tar disposal methods.

The invention provides a filling type tubular micro mixer and application thereof. The mixer comprises a feeding pipe body; the mixing pipe body is connected with the feeding pipe body in series; the mixing pipe body comprises grading pipe bodies which are connected in series; the grading pipe body comprises a mixing pipe cavity, and turbulent flow particles are filled in the grading pipe body in a layered mode. Each layer of turbulent flow particles are consistent in size; the sizes and the numbers of the turbulent flow particles of adjacent layers are different; fluid channels are formed between the inner wall of the mixing pipe cavity and the outer walls of the turbulent flow particles and between the outer walls of the adjacent turbulent flow particles, so that fluid is disturbed; and the temperature control jacket is arranged on the outer side of the mixing pipe body. The technical problem to be solved is how to provide the filling type tubular micro mixer, so that fluid is more fully mixed, the reaction is quicker, and the reaction yield is improved. When the catalyst is used for continuous preparation of nitrochlorobenzene, the specific surface area is larger, local mass transfer and heat transfer are better, temperature is controlled in a segmented manner, local overheating is inhibited, the conversion rate of chlorobenzene and the yield of mononitrochlorobenzene are increased, and the generation of explosive poly-nitrochlorobenzene by-products is reduced.

The invention discloses a nitrogen heterocyclic ring-containing compound and a preparation method and application thereof, and the preparation method of the compound comprises the following steps: carrying out condensation reaction on 2, 5-diaminopyrimidine and 2, 6-dimethyl-4-nitrochlorobenzene under the action of alkali to obtain an intermediate 1; and introducing hydrogen into the intermediate 1 and 5-methyl-2-hexanone under the action of a catalyst to carry out reductive condensation reaction to obtain a product. The compound has a special structure, contains pyrimidine and benzene ring groups, has a good ozone protection effect when being used in rubber products, has different substituent groups on benzene rings, does not generate p-benzoquinone or o-benzoquinone toxic substances, is higher in environmental protection property and large in molecular weight, is not easy to discolor and emigrate when being used in the rubber products, and has a good application prospect. And the anti-aging agent has high application value in the aspect of aging resistance of rubber materials.

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 utility model discloses a nitrochlorobenzene freezing point detection device which comprises a base, and a test device, a power supply and control module and a freezing module are arranged on the base. A refrigerator is arranged in the freezing module and is used for providing cooling capacity for the test device; the power supply and control module comprises a power supply and a controller; the power supply is used for supplying power to the freezing module and the test device; the test device comprises a fixed table, a lifting driving device, a lifting table, a test container and a bath. The test container comprises a test bottle, a stirrer, a temperature sensor, a torque sensor, a test bottle cap and a dropwise adding meter. The controller judges whether the test sample reaches a freezing point or not according to the torque value of the stirring shaft, when the test sample reaches the freezing point, the controller stores the measured temperature of the temperature sensor, and the temperature is the freezing point temperature of the test sample. The nitrochlorobenzene freezing point detection device can replace manual work to automatically detect the nitrochlorobenzene freezing point, and is high in detection efficiency, high in detection precision and good in repeatability.

The invention relates to a preparation method of 3, 4 '-diaminodiphenyl ether (3, 4'-ODA). A first aspect of the present application relates to a method for preparing 3-amino-4 '-nitrodiphenyl ether, comprising: (1) synthesizing 3-amino-4'-nitrodiphenyl ether from p-nitrochlorobenzene, m-aminophenol in a first solvent in the presence of a condensing agent wherein the first solvent is selected from sulfones, sulfoxides, amides, phosphamides, and step (1) is carried out under reduced pressure, and step (2) is carried out under reduced pressure; and removing the generated water during the proceeding of the step (1). The invention relates to a method for preparing 3, 4 '-ODA in the second aspect, and the method comprises the steps of (a) preparing 3-amino-4'-nitrodiphenyl ether through the method in the first aspect, and (b) reducing the 3-amino-4 '-nitrodiphenyl ether obtained in the step (a) in the presence of a reducing agent to obtain the 3, 4'-ODA. The invention further relates to the 3, 4 '-ODA obtained through the method in the second aspect.

The invention relates to a series countercurrent continuous nitration reaction system and a method for preparing 2, 4-dinitrochlorobenzene, the series countercurrent continuous nitration reaction system comprises an extraction system, a nitration system, a pre-washing system, a neutralization system and a washing system which are connected in sequence, chlorobenzene is added from the extraction system and continuously flows through each nitration machine to participate in reaction, and then the reaction is completed; concentrated sulfuric acid is added from the last nitration machine, sequentially flows through each nitration machine in a countercurrent manner, finally becomes waste acid and enters the extraction system, concentrated nitric acid is added into each nitration machine in proportion, each nitration machine is provided with a separation device, a separated organic phase enters the next device, and the waste acid returns to the previous device; a nitration substance obtained through the reaction sequentially enters a nitration reseparator, a pre-washing system, a neutralization system and a washing system, and finally a finished product 2, 4-dinitrochlorobenzene is obtained through separation. The 2, 4-dinitrochlorobenzene is prepared by adopting the series countercurrent continuous nitration system, the raw material consumption is low, the temperature control is low, the generated wastewater is less, the wastewater is recycled, and the quality and the yield of the produced 2, 4-dinitrochlorobenzene can reach the high-quality level.

This utility model relates to the field of nitrochlorobenzene purification technology, and discloses a p-nitrochlorobenzene purification device, including a mounting plate, a heating plate fixedly mounted on the bottom of the mounting plate, a mixing box fixedly connected to one side of the mounting plate, a crushing barrel connected through the upper surface of the mixing box, a crystallization barrel connected through the upper surface of the crushing barrel, a first variable speed motor fixedly mounted on the upper surface of the crystallization barrel, and a crushing frame fixedly connected to the output end of the first variable speed motor. This utility model facilitates the filtration of crushed coarse materials, and the addition of springs not only enhances the elasticity of the filter plates, but also causes the filter plates to vibrate back and forth, effectively improving the filtration effect and helping to filter materials of different particle sizes more finely. Furthermore, by releasing the limiting block from obstructing the crystallization plate, the operator can easily pull the crystallization plate out from inside the limiting ring for necessary cleaning, replacement, or maintenance.

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 application discloses a preparation method of high-purity N,N'-bis(4-amino-2-chlorophenyl) terephthalamide with purity above 99.5% and application thereof. The high-purity N,N'-bis(4-amino-2-chlorophenyl) terephthalamide is prepared from 2-chloro-4-nitrophenylamine and terephthaloyl chloride as starting materials, and the preparation comprises the following steps: firstly, condensation reaction is carried out to obtain N,N'-bis(4-nitro-2-chlorophenyl) terephthalamide; and then, catalytic hydrogenation reaction is carried out to obtain N,N'-bis(4-amino-2-chlorophenyl) terephthalamide. The condensation reaction is carried out in a toluene solvent at a temperature of 90-100 DEG C; and the catalytic hydrogenation reaction is carried out in a tetrahydrofuran or N,N-dimethylformamide or n-butanol solvent at a temperature of 60-70 DEG C. The prepared N,N'-bis(4-amino-2-chlorophenyl) terephthalamide has purity above 99.5%, and can be applied to preparation of a liquid crystal alignment agent. The liquid crystal alignment agent prepared from the N,N'-bis(4-amino-2-chlorophenyl) terephthalamide has a high and stable pre-tilt angle, a high voltage holding ratio, a low residual direct current voltage, a low ion concentration and good rubbing resistance, and can be used in a high-generation TFT liquid crystal production line.

The invention discloses a preparation method of a medical intermediate 2-(4-nitrophenyl) butyric acid, and belongs to the technical field of medical fine chemical engineering. According to the method, p-nitrochlorobenzene and alkyl cyanoacetate are used as raw materials to react to prepare an intermediate 2-cyano-2-(4-nitrophenyl) acetoacetate, and then the intermediate 2-cyano-2-(4-nitrophenyl) acetoacetate reacts with diethyl sulfate under the alkaline condition to obtain the 2-cyano-2-(4-nitrophenyl) butyric acid alkyl ester. And finally, hydrolyzing through a concentrated sulfuric acid and acetic acid mixed system to obtain the 2-cyano-2-(4-nitrophenyl) butyric acid. The raw materials and reagents used in the method are cheap and easy to obtain, the process is simple and easy to implement, and the cost advantage is remarkable. Meanwhile, the adopted reaction route does not generate isomeride impurities such as 2-(2-nitrophenyl) butyric acid and the like, the yield is high, and the quality of the obtained product is good.