26 results about "O-nitroaniline" patented technology

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 application discloses a method for preparing 2-nitro-2'-hydroxy-5'-tert-octyl azobenzene in a water medium system. The method controls the molar dosage ratio of tert-octyl phenol and NaOH in an emulsification process, controls the mass concentration of tert-octyl phenol in an emulsion, controls the molar dosage ratio of o-nitroaniline and tert-octyl phenol, and controls the mass dosage ratio of an anionic high polymer surfactant and a non-ionic surfactant, so that 2-nitro-2'-hydroxy-5'-tert-octyl azobenzene with high purity is prepared. Compared with a traditional synthesis process, the method uses water as a reaction medium, avoids the use of an organic solvent, effectively reduces the difficulty in treating subsequent wastewater, and achieves a target product yield of more than 95% and a purity of 91.79%-94.52%.

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 application discloses a resin for adsorbing o-nitroaniline and a preparation method thereof, and belongs to the technical field of resin production. After polystyrene resin is subjected to a chloroacetylation reaction, the polystyrene resin is reacted with octadecylamine to graft long-chain alkyl, imino and carbon groups on the molecular chain structure of the polystyrene resin. The long-chain alkyl can form a network winding structure, facilitating the contact adsorption of the resin and o-nitroaniline and enhancing the hydrophobicity of the resin. Hydrophobic interaction and hydrogen bond interaction exist between the grafted polystyrene resin and o-nitroaniline, which can improve the adsorption performance of the resin on o-nitroaniline in wastewater, is beneficial to the recovery of o-nitroaniline in the wastewater and reduces the pollution caused by wastewater discharge.

The utility model relates to a water absorption tank for material tail gas treatment in paranitroaniline and ortho-nitroaniline production, which comprises a circular tank body, water is contained in the tank body, a sealing cover is arranged on the tank body, a material tail gas inlet and an exhaust outlet are arranged on the sealing cover, an exhaust pipe is arranged on the exhaust outlet, and a water outlet is arranged on the exhaust pipe. A gas inlet pipeline extending below the liquid level in the tank body is arranged on the material tail gas inlet; a section of distributor for uniformly releasing material tail gas is arranged from the part, extending below the liquid level, of the gas inlet pipeline to the end part; a water adding opening is formed in the upper end of the side wall of the tank body, an overflow opening is formed in the middle of the side wall of the tank body, an emptying opening is formed in the lower end of the side wall of the tank body, and a transparent visible observation window is arranged at the upper water adding limit position of the side wall of the tank body; a heater is arranged on the outer wall of the tank body; a temperature measuring opening is formed in the lower portion of the side wall of the tank body. According to the utility model, the problem that the absorption tower is blocked in the prior art is solved, material tail gas is purified, materials can be recycled, and the cost is saved.

The invention belongs to the technical field of organic synthesis, and discloses a synthesis method and application of propylthio-o-phenylenediamine. The invention provides a method for hydrogenation reduction of propylthio-o-nitroaniline into propylthio-o-phenylenediamine in the presence of a catalyst composed of a water-soluble sulfonated phosphine ligand and rhodium salt. Phase-transfer catalysis is used for selective reduction of o-nitroaniline, a water-organic two-phase catalysis system is prepared from a water-soluble sulfonated phosphine ligand and rhodium salt, a catalyst is dissolved in a water phase in the reaction system, a product is dissolved in an organic phase in the reaction system, after the reaction is finished, a water layer containing the catalyst can be recycled, an organic layer is used for separating the product, and the yield of o-nitroaniline is improved. The problem that a catalyst and a product are difficult to separate in a conventional homogeneous system is solved. The synthesis method has the advantages of mild reaction conditions, environmental protection, high yield and purity, relatively low cost and the like. The synthesis method of the propylthio-o-phenylenediamine provided by the invention can be applied to preparation of albendazole and intermediates thereof.

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 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 application discloses a kind of o-nitroaniline production wastewater treatment processes, belong to wastewater treatment field, the device includes the following steps: step one: resin prewash, step two: resin preheating, step three: resin adsorption, the adsorption barrel in resin preheating is taken out, while o-nitroaniline wastewater is placed into a group of processing barrels, adsorption barrel is placed into a group of processing barrels to carry out adsorption to o-nitroaniline in the o-nitroaniline wastewater in processing barrel inside;Step four: resin desorption, methanol is added in processing barrel and is desorbed;By first prewashing macroporous resin, remove the impurities in macroporous resin, increase the adsorption state of macroporous resin, then preheat macroporous resin again, promote the expansion of the internal pore of macroporous resin, increase the specific surface area of resin, improve the adsorption capacity of resin, to improve the effect of macroporous resin on o-nitroaniline wastewater adsorption treatment.

The invention discloses a resin for adsorbing o-nitroaniline and a preparation method thereof, and belongs to the technical field of resin production, polystyrene resin is subjected to a chloroacetylation reaction and then reacts with octadecylamine, a long-chain alkyl group, an imino group and a carbon group are grafted on a molecular chain structure of the polystyrene resin, the long-chain alkyl group can form a network winding structure, and the long-chain alkyl group can form a network winding structure; the contact adsorption of the resin and o-nitroaniline is facilitated, and the hydrophobicity of the resin can be enhanced. Hydrophobic interaction and hydrogen-bond interaction exist between the grafted polystyrene resin and the o-nitroaniline, the adsorption performance of the resin to the o-nitroaniline in the wastewater can be improved, recovery of the o-nitroaniline in the wastewater is facilitated, and wastewater discharge pollution is reduced.

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 relates to the technical field of ortho-nitroaniline production, and discloses a tail gas absorption device in an ortho-nitroaniline production process, which comprises a water tank, a fan, a conveying pipe, a barrier plate, a motor I, a stirring rod, a heating pipe, a through pipe, a saline water tank, a gas distribution pipe and a cleaning mechanism. According to the tail gas absorption device in the o-nitroaniline production process, a fan is started to drive tail gas to reach the inner wall of a conveying pipe, so that the tail gas reaches the position below a barrier plate and reaches the interior of hot water at the same time, the tail gas in o-nitroaniline production is intercepted through the barrier plate, and a first motor drives a stirring rod to rotate and then drives the hot water to rotate; the hot water and the o-nitroaniline production tail gas are fully reacted and absorbed, and the ammonia gas reaches the through pipe, is driven into the gas-distributing pipe and is discharged through a plurality of groups of gas outlet holes above the gas-distributing pipe, so that the ammonia gas is fully contacted with the saline water, and the effects of conveniently fully reacting the o-nitroaniline production tail gas with the hot water and improving the dissolving efficiency are achieved.

The utility model discloses an ortho-nitroaniline liquid material recovery device, relates to the technical field of ortho-nitroaniline recovery treatment, and solves the problems that in the filtering process of an existing recovery device, due to the fact that ortho-nitroaniline liquid materials directly impact a filter screen, the filter screen is damaged due to deformation after being used for a long time, and the recovery effect is poor. The filtering operation of the o-nitroaniline liquid material is influenced. Comprising a treatment tank and a feeding hole formed in the top surface of the treatment tank; the liquid guide channel is arranged at the lower end of the interior of the treatment tank, the liquid guide channel is divided into a channel I and a channel II which are spliced together, and a filter screen is arranged in a port of the channel II; a pair of miniature telescopic cylinders; according to the utility model, the o-nitroaniline liquid material impacts on the flow divider and drives the flow divider to rotate, so that the impact force of the o-nitroaniline liquid can be reduced, the o-nitroaniline liquid material is prevented from directly impacting the filter screen, the filter screen is prevented from being deformed and damaged, and the service life of the filter screen is prolonged.

The invention discloses an o-phenylenediamine borane derivative as well as a preparation method and application thereof in treatment of morphine addiction, and the preparation method comprises the following steps: carrying out substitution reaction on an o-nitroaniline compound and 2-(N, N-dimethylamino) ethyl bromohydrobromide under the action of alkali to obtain a compound c; reducing nitryl by the compound c under the action of a reducing agent to obtain a compound d; and reacting the compound d under the action of BH3. THF to obtain the o-phenylenediamine borane derivative. Compared with DMT, the o-phenylenediamine borane derivative prepared by the preparation method disclosed by the invention has the advantage that the anti-neuroinflammation activity is remarkably improved.

The application discloses a kind of full continuous flow preparation methods of pyriproxyfen.The chloro o-nitroaniline solution and hydrogen are transported to fixed bed reactor to carry out continuous catalytic hydrogenation reaction, and the 4-chloro o-phenylenediamine reaction mixture obtained is transported to microchannel mixer and reactor with ethyl glyoxylic acid solution to carry out continuous cyclization reaction, and the 2-hydroxy-6-chloroquinoxaline suspension obtained is entered into continuous online filtering device, and the mixture is transported to micro-mixer and continuous flow reactor with phosphorus oxychloride by peristaltic pump, and the effluent reaction liquid and hydroquinone / catalyst mixture are transported to another fixed bed reactor to carry out continuous etherification;Reaction mixture and (S)-2-chloropropionic acid ethyl ester are entered into fixed bed reactor to carry out continuous etherification reaction;Product pyriproxyfen is obtained;Compared with traditional batch kettle type synthesis method, the method has short reaction time, high product yield, high degree of automation, high process continuous efficiency, high space-time yield, low energy consumption and easy industrial amplification application.

The invention discloses a preparation method of o-phenylenediamine, and belongs to the technical field of organic synthesis. The invention relates to a preparation method of o-phenylenediamine, which comprises the following steps: pressurizing hydrogen to reduce o-nitroaniline in the presence of a solvent and a modified catalyst to obtain o-phenylenediamine, wherein the modified catalyst is a palladium-based catalyst loaded by a modified nitrogen and boron doped carbon nanotube, and the modified nitrogen and boron doped carbon nanotube is a nitrogen and boron doped carbon nanotube treated by (11-mercaptoundecyl)-N, N, N-trimethyl ammonium bromide. In the process of preparing o-phenylenediamine through catalytic reduction of o-nitroaniline, the modified catalyst and the modified nitrogen-boron-doped carbon nanotubes are used, palladium can be firmly fixed to the carbon nanotubes, agglomeration or loss of palladium in the reaction process is prevented, the cycle performance of the catalyst is improved, and the catalytic capacity of the palladium-based catalyst can be improved.

The invention discloses a method for recovering ammonium chloride from waste liquid in preparation of o-nitroaniline, and belongs to the technical field of wastewater treatment. Comprising the following steps: S1, enabling the o-nitroaniline waste liquid to sequentially pass through a three-stage countercurrent washing device, and regulating the pH step by step to obtain an ammonium chloride crude extract; s2, preparing PS-DVB microspheres by taking styrene and divinylbenzene as monomers, ammonium persulfate as an initiator and polyvinylpyrrolidone as a dispersant, constructing a TiO2 shell layer on the outer layer of the PS-DVB microspheres, and then loading graphene oxide to obtain PS-DVB-coated TiO2 / GO resin; s3, the PS-DVB-coated TiO2 / GO resin is packed, the ammonium chloride crude extract is introduced into an adsorption column, effluent is collected and subjected to multiple-effect evaporation, ammonium chloride is obtained from a solid phase, and evaporated liquor and the resin are recycled and reused. Through cooperation of multiple technologies, high recovery rate, low residue and cycle economy of ammonium chloride are realized, and the method has industrial popularization value.

The invention provides a preparation method and application of 2-(2 '-hydroxy-5'-tert-octylphenyl) benzotriazole, and relates to the technical field of ultraviolet absorbers.The preparation method comprises the following steps that S1, an acid solution of ortho-nitroaniline is obtained, a sodium nitrite solution is dropwise added in several times for a diazotization reaction, and a 2-nitrodiazobenzene salt solution is obtained; s2, the 2-nitrodiazobenzene salt solution and p-tert-octylphenol are subjected to a coupling reaction in an alkali solution, and an intermediate is obtained; s3, the intermediate is subjected to a reduction reaction, and 2-(2 '-hydroxy-5'-tert-octyl phenyl) benzotriazole is obtained. In the technical scheme provided by the invention, the feeding rate of the sodium nitrite solution is controlled in a manner of adding the sodium nitrite solution for several times, and excessive or insufficient nitrous acid generated by conversion of the sodium nitrite is prevented, so that the balance between the nitrous acid generation rate and the diazotization reaction consumption rate is maintained, and the yield and purity of the product are further improved.

The invention discloses a fully continuous flow preparation method of quizalofop-p-ethyl. The method comprises the following steps: conveying a chloro-o-nitroaniline solution and hydrogen into a fixed bed reactor, carrying out a continuous catalytic hydrogenation reaction, conveying an obtained 4-chloro-o-phenylenediamine reaction mixed solution and an ethyl glyoxylate solution into a micro-channel mixer and a reactor, and carrying out a continuous cyclization reaction, the obtained 2-hydroxy-6-chloroquinoxaline turbid liquid enters a continuous online filtering device, the mixed liquid and phosphorus oxychloride are conveyed to a micro-mixer and a continuous flow reactor through a peristaltic pump, and the flowing-out reaction liquid and hydroquinone / catalyst mixed liquid are conveyed to another fixed bed reactor for continuous etherification; a reaction mixed solution and (S)-2-ethyl chloropropionate enter a fixed bed reactor for a continuous etherification reaction; the product quizalofop-p-ethyl is obtained; compared with a traditional intermittent kettle type synthesis method, the method disclosed by the invention is short in reaction time, high in product yield, high in automation degree, high in process continuous efficiency, high in space-time yield, low in energy consumption and easy to industrially amplify and apply.

The utility model discloses an o-nitroaniline reaction kettle, which relates to the technical field of o-nitroaniline production and is characterized in that a feeding hole is formed in the top end of a kettle body, a plurality of heating boxes are fixedly connected to the inner wall of the kettle body along the axial line direction, heating elements are fixedly connected to the inner walls of the heating boxes, and a bearing frame is arranged at the bottom of the kettle body. The bearing frame is rotationally connected with the outer wall of the kettle body, the servo motor is fixedly connected to the top end of the kettle body, the bottom end of the servo motor is fixedly connected with a rotating shaft, and the outer wall of the rotating shaft is fixedly connected with stirring blades; the heating element operates, heat provided by the heating element is transmitted to the o-nitroaniline through the heating box, the heating area of the o-nitroaniline is increased by using the heating box and the heating element, the heat exchange efficiency of the o-nitroaniline is improved, and therefore the processing efficiency of the o-nitroaniline is improved; and the heating box can block the o-nitroaniline, so that the o-nitroaniline further rolls in the rotating process.

The invention discloses a method for recycling o-nitroaniline in wastewater, and belongs to the technical field of wastewater treatment.The recycling method comprises the following steps that S1, wastewater containing o-nitroaniline is subjected to pH adjustment and cooling; s2, collecting the cooled wastewater, putting the wastewater into an evaporator for evaporation, and putting the wastewater subjected to flash evaporation into a filter press with filter cloth for filtration; s3, putting the filtered wastewater into a reaction tank, carrying out heating reaction, and feeding the wastewater into a water washing tower through a recycled aniline pump for water washing; and S4, transferring washing liquor after washing into an extraction kettle filled with an extraction agent for extraction, transferring an organic phase out for recovery, and enabling a water phase to enter a wastewater treatment section, thereby completing recovery. The method for recovering o-nitroaniline in wastewater provided by the invention has excellent recovery efficiency, the recovered o-nitroaniline has a certain economic value, the economic benefit of an enterprise is favorably improved, meanwhile, the COD index of the treated wastewater is greatly reduced, and the pollution to the environment is reduced.

The invention discloses a production process of o-nitroaniline, and belongs to the technical field of chemical production. According to the production process, saturated sodium chloride brine is used as a reaction medium, o-nitrochlorobenzene and ammonia water are subjected to ammonolysis to prepare o-nitroaniline, and liquid ammonia is added in the reaction by adopting a staged ammonia adding method to supplement ammonia consumed in the early reaction. According to the method, while the high-concentration saline water is used for inhibiting side reaction, the density of a water phase is increased, the density difference between an oil phase and the water phase is enhanced, layering is accelerated, separation of the product o-nitroaniline and the water phase is achieved, generation and residues of impurities are reduced, the solubility of NH4Cl is remarkably reduced through the common ion effect, rapid precipitation of ammonium chloride in the cooling layering stage is achieved, and the quality of the product is improved. Residues of ammonium chloride in the product are reduced and the product purity is improved. Liquid ammonia is added in the reaction, ammonia consumption is supplemented, forward proceeding of the reaction is promoted, thorough reaction is ensured, raw material residues and side reaction risks are reduced, and the conversion rate of o-nitrochlorobenzene is increased.

The invention discloses a tail gas condensing device for o-nitroaniline production, and relates to the technical field of o-nitroaniline production, the tail gas condensing device comprises a cylindrical condensing barrel, a conical condensing plate is arranged on the lower side of the top of the condensing barrel, the condensing plate is vertically arranged, and the conical head of the condensing plate faces downwards; a plurality of first concave parts are formed in the lower side surface of the condensation plate, a tail gas exhauster is further rotationally arranged below the condensation plate, and an exhaust area of the tail gas exhauster directly faces the conical surface of the condensation plate; due to the conical condensation plate, on one hand, the contact area between the tail gas and the condensation plate is increased, and on the other hand, the tail gas can be guided; and the first concave part on the condensation plate can increase the retention time of the tail gas on the condensation plate, and meanwhile, the heat dissipation area of the condensation plate is increased, so that the cooling effect on the tail gas is improved.

The invention discloses a kind of o-nitroaniline purification process, belong to the field of purification technology, comprise the following steps:The first step, prepare adsorbent:Hydrotalcite-like substance and absolute ethanol are mixed, vinyl trimethylsiloxane is added, stirring 30min, pH is adjusted, stirring reaction 4h, obtains carrier;Cetyl trimethyl ammonium bromide is added in deionized water, under the condition of temperature being 40 DEG C, carrier, methacryloyloxyethyl trimethyl ammonium chloride, unsaturated monomer, N, N-methylene bisacrylamide and benzoyl peroxide are added while stirring, stirring reaction, obtains adsorbent;Second step, adsorption treatment:Adsorbent is added to the o-nitroaniline crude product prepared, carries out adsorption treatment.The present invention, by adding adsorbent in the purification process of the conventional purification process of o-nitroaniline, by the chloride ion in adsorbent adsorption crude product, improves o-nitroaniline purity, meets the requirement of subsequent workshop section.

The application belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing 2-methyl-8-nitroquinoline. The method comprises the following steps: in an inert gas atmosphere, under the action of an oxidant, o-nitroaniline is first reacted with a protonic acid, and then an aldehyde compound is added to perform a condensation reaction, and 2-methyl-8-nitroquinoline is obtained. In the condensation process, the inert gas protection is adopted to avoid the generation of tar-like by-products in the reaction system, and the yield and purity of 2-methyl-8-nitroquinoline are improved. A new type of oxidant, such as 1,2-dinitrobenzene, dinitrobenzene, 3,5-dinitroaniline and 2,4-dinitroaniline, is adopted to avoid the participation of the substrate o-nitroaniline in the reaction as an oxygen source, and the yield and purity of the product are improved. Meanwhile, the oxidant itself is completely or partially generated into o-nitroaniline, which can be used as a substrate to react, and the yield of the product is further improved. The reaction condition is mild, raw materials are cheap, and the method is suitable for industrial production.

The invention discloses a preparation method of high-purity o-nitroaniline, and belongs to the technical field of fine chemical synthesis. Comprising the following steps: S1, uniformly mixing o-nitrochlorobenzene and stronger ammonia water, and heating for reaction to obtain a crude product mixture; s2, cooling the crude product mixture, adding an extracting agent for extraction, and standing for layering; concentrating and crystallizing a water phase to obtain a byproduct ammonium chloride, wherein an organic phase is an o-nitroaniline solution; s3, evaporating the o-nitroaniline solution through a falling film evaporator to remove 90%-95% of the solvent, and condensing and recycling the solvent to obtain an o-nitroaniline concentrated solution; and S4, distilling the o-nitroaniline concentrated solution by using a molecular distiller, and returning residues to the extraction process to obtain a distillate which is high-purity o-nitroaniline. According to the method, through extraction purification, low-temperature evaporation and molecular distillation, the problems of high chloride ion residue, high energy consumption and insufficient product purity in a traditional process are solved, and meanwhile resource utilization of by-products is achieved.