35 results about "Chloronitrobenzene" patented technology

The invention discloses a synthesis method of 5-nitro-2-aminophenol, which comprises the following steps: by using 2-chloro-4-nitroaniline as a raw material, providing an amino protecting group by using di-tert-butyl dicarbonate ester to obtain a compound 3; carrying out hydrolysis reaction in an alkaline environment to hydrolyze chlorine groups on benzene rings into hydroxyl groups to obtain a compound 4; and removing an amino protecting group under an acidic condition to obtain the 5-nitro-2-aminophenol. According to the method, 2-chloro-4-nitroaniline is used as a starting raw material, compared with expensive ortho-aminophenol, the cost of the raw material can be remarkably reduced, use of expensive catalysts in the hydrolysis process is avoided through amino protection, generation of the byproduct 2-amino-4-nitrophenol is effectively reduced, and the yield of the 2-chloro-4-nitrophenol is increased. And the synthesized 5-nitro-2-aminophenol has relatively high purity (99.5%) and relatively high yield (-86%). The method has the advantages of conventional production steps and conventional process equipment, and has a good application prospect.

This invention relates to a method for the liquid-phase adsorption separation and purification of 2,3-dichloronitrobenzene and 3,4-dichloronitrobenzene, belonging to the field of chemical separation. This method for the simultaneous separation and purification of 2,3-dichloronitrobenzene and 3,4-dichloronitrobenzene involves preparing small spherical molecular sieve adsorbents from USY molecular sieves, silicon coupling agent-modified illite, and biomass polysaccharides, which are then loaded into a countercurrent simulated moving bed for separation and purification. This method can simultaneously obtain 2,3-dichloronitrobenzene and 3,4-dichloronitrobenzene with a purity ≥99%. The separation and purification method adopted in this invention is not only energy-efficient and highly effective, but also enables continuous production of two high-purity dichloronitrobenzenes, possessing significant industrial application value.

The invention discloses a method for treating polychlorinated nitrobenzene-containing wastewater by adopting calcium hydroxide alkaline hydrolysis. The method comprises the following steps: firstly, adding calcium hydroxide into wastewater containing polychlorinated nitrobenzene, carrying out hydrolysis reaction under stirring and temperature control conditions, carrying out nucleophilic substitution on activated chlorine substitution sites and nitro substitution sites in polychlorinated nitrobenzene molecules by utilizing hydroxyl ions to generate phenolic substances such as trinitrodichlorophenol and the like, and separating the phenolic substances to obtain the polychlorinated nitrobenzene-containing wastewater. Performing ultrasonic treatment on the first treatment liquid until the solution turns yellow and the chromaticity is not increased any more to obtain a first treatment liquid, and performing ultrasonic treatment, washing and filtering on the first treatment liquid to remove precipitated solids to obtain the treatment liquid. According to the method disclosed by the invention, the primary attenuation of the polychlorinated nitrobenzene-containing wastewater is realized, and the treatability of the wastewater is improved.

The present application relates to the technical field of chemical synthesis, in particular to a method for inhibiting poisoning of a proton exchange membrane in one-pot production of p-chlorophenylhydrazine, which uses p-chloronitrobenzene as a substrate and tin dichloride for reduction reaction to realize one-pot synthesis process of p-chlorophenylhydrazine.The method does not need intermediate separation steps, can directly feed materials, effectively reduces loss of raw materials, and realizes continuous reduction of tin tetrachloride by reasonable inhibition of poisoning of the proton exchange membrane, recycles tin dichloride, and re-puts it into the nitrobenzene reduction step.Compared with the traditional method, the method solves the yield reduction problem caused by p-chlorophenylhydrazine preparation in steps and purification, solves the problem of poisoning of the proton exchange membrane by phenylhydrazine hydrochloride, is suitable for industrial production environment, improves the product yield, reduces environmental pollution, has low cost, and is suitable for efficient continuous production of important chemical intermediate p-chlorophenylhydrazine.

The application discloses a polypyrrone-derived carbon-coated metal catalyst and a preparation and application thereof. The catalyst prepared by the application provides a nitrogen-doped carbon layer by polypyrrone, which not only provides protection for an active center, but also promotes electron transmission between carbon layers by the conductive property of the polypyrrone-derived carbon layer itself. The polypyrrone-derived carbon-coated metal catalyst is applied to a catalytic hydrogenation reaction of chloronitrobenzene containing sulfur-containing poisons, and shows excellent activity, selectivity and stability.

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

The invention discloses a method for synthesizing loxapine succinate, which comprises the following steps of: carrying out substitution reaction by using 2-nitrofluorobenzene and 2-hydroxy-4-chloromethyl benzoate as raw materials to generate 5-chloro-2-(2-nitrophenoxy) benzoate; nitryl is reduced, and 5-chloro-2-(2-aminophenoxy) benzoate is generated; the method comprises the following steps: carrying out an intramolecular ring closing reaction to generate 2-chlorodibenzo [b, f] [1, 4] oxazepine-11 (10H)-ketone; 2, 11-dichlorodibenzo [b, f] [1, 4] oxazepine is obtained through a reaction and chlorination; the method comprises the following steps: carrying out a C-N coupling reaction of methyl piperazine to generate 2-chloro-11-(4-methylpiperidine-1-yl) dibenzo [b, f] [1, 4] oxazepine; and salifying with succinic acid to generate the loxapine succinate. The method is easily available in raw materials, simple in process and suitable for large-scale production.

The application discloses a method for preparing 2-fluoro-3-chloronitrobenzene, which comprises the following steps: (1) mixing a crown ether and a quaternary ammonium salt ionic liquid uniformly according to a molar ratio of 1-2:1 to obtain a crown ether-quaternary ammonium salt ionic liquid composite catalyst; (2) adding 2,3-dichloronitrobenzene, anhydrous fluorinating reagent and the crown ether-quaternary ammonium salt ionic liquid composite catalyst obtained in the step (1) into a reactor, heating to 150-210 DEG C under the protection of inert gas, and fully reacting under the condition that the rotating speed is 600-1000 rpm to generate 2-fluoro-3-chloronitrobenzene. The application has the advantages of mild reaction condition, short reaction time, high yield and purity of the final product, and is a suitable industrialized synthesis method.

The invention discloses a palladium-inlaid porous carbon-coated honeycomb ceramic monolithic catalyst as well as preparation and application thereof. The preparation method of the catalyst comprises the following steps: stirring and mixing phenol, a formaldehyde aqueous solution and sodium hydroxide, then adding a solution containing a palladium source, and polymerizing to obtain a phenolic resin reaction solution containing palladium; then immersing the cordierite honeycomb ceramic in a phenolic resin reaction solution containing palladium for 8-16 hours, taking out the cordierite honeycomb ceramic, blowing away redundant phenolic resin in pore channels of the cordierite honeycomb ceramic, then carrying out first-stage curing and second-stage roasting on the honeycomb ceramic in a nitrogen-oxygen mixed atmosphere, and then carrying out high-temperature carbonization in a nitrogen atmosphere, so as to obtain the catalyst. And cooling to obtain the palladium-inlaid porous carbon-coated honeycomb ceramic monolithic catalyst. The invention provides an application of the palladium-inlaid porous carbon-coated honeycomb ceramic monolithic catalyst in a selective catalytic hydrogenation reaction of chloronitrobenzene to generate chloroaniline. The catalyst provided by the invention has the advantages of low loading capacity, low cost and high stability.

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 invention discloses a preparation method of 2-amino-6-nitrobenzamide (2-amino-6-nitrobenzamide). The method comprises the following specific process: carrying out ammonolysis on 2-chloro-6-nitrobenzonitrile as shown in a formula (I) under the action of a cuprous catalyst, an alkaline substance, an organic solvent and ammonia water to synthesize 2-amino-6-nitrobenzamide as shown in a formula (II). By adopting a limited technology, the use of a highly toxic reagent is avoided, and the operation safety is improved; the cuprous catalyst is adopted to replace an expensive metal cuprous catalyst, so that the method has the advantages of good reaction selectivity, mild conditions, high conversion rate, low cost and easiness in large-scale production;

The invention belongs to the field of water treatment, and relates to a method for intensively removing parachloronitrobenzene in water after removing phosphorus pollution in water by using nano zero-valent iron. The method comprises the following steps: adding nano zero-valent iron into phosphorus-containing to-be-treated water, carrying out a stirring reaction to remove phosphorus in the water, then adding parachloronitrobenzene-containing to-be-treated water, and continuously carrying out a stirring reaction to remove parachloronitrobenzene in the water. The invention provides a novel and efficient method for removing parachloronitrobenzene in water, nanoscale zero-valent iron is used for removing phosphorus and organic pollutants, parachloronitrobenzene can be rapidly and efficiently removed, and the method can adapt to a wide pH value range. The phosphorylated nano zero-valent iron generated in situ after phosphorus removal of the nano zero-valent iron has good reduction performance, and parachloronitrobenzene in water can be efficiently removed. Meanwhile, the nZVI in the method can remove phosphorus and parachloronitrobenzene pollution in water at the same time, the effect of treating waste with waste can be achieved, operation is easy, and the method has wide application prospects.

The invention relates to a preparation method of an iron oxide-loaded noble metal catalyst and application of the iron oxide-loaded noble metal catalyst in a reaction of catalyzing hydrogenation of o-chloronitrobenzene to synthesize o-chloroaniline. Wherein the iron oxide is a carrier, the precious metal Pt or Ru is an active component, the mass fraction is 0.5%-4%, and the particle size of the precious metal is smaller than 3 nm. The interaction between the noble metal nanoparticles and the iron oxide carrier is enhanced by adopting a hydrothermal method, so that the dispersion of active components is facilitated. When the catalyst is used for catalyzing hydrogenation of o-chloronitrobenzene to synthesize o-chloroaniline, a dechlorination inhibitor does not need to be additionally added, the catalytic hydrogenation reaction can be carried out at normal pressure, and the activity is high; the oxidation valence state of iron can be controlled by regulating and controlling hydrothermal conditions, so that the surface electron state of noble metal is further influenced, dechlorination in the reaction process is effectively inhibited, and the product selectivity is high; and the catalyst has magnetism and is easy to recycle and reuse.

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

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

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

The application belongs to the field of medicine, and discloses a compound with the structure of formula I, a preparation method of the compound, and the compound is a pyrazole acylhydrazine derivative containing a diphenyl ether unit, which is obtained by substituting p-chloronitrobenzene with phenol, and then by reduction, diazotization, re-reduction, hydrochloric acid removal and hydrazide reaction; the pyrazole acylhydrazine derivative containing the diphenyl ether unit has obvious inhibitory effect on human pancreatic cancer cells, human breast cancer cells and human gastric cancer cells, and can be used as a potential new type of antitumor candidate drug molecule.

This invention relates to the field of microbial technology, and in particular to a microbial composition and its application that simultaneously degrades ginseng allelochemicals and pesticide residues, and antagonizes pathogens. The microbial composition provided by this invention degrades ginseng allelochemicals (ferulic acid, gallic acid, salicylic acid, and cinnamic acid), removes pentachloronitrobenzene pesticide residues from ginseng-growing areas, and antagonizes ginseng pathogens (Fusarium solani, Fusarium oxysporum, Alternaria alternata, and Penicillium desquam). Furthermore, the bio-organic fertilizer made from the bag-cultivated Gastrodia elata fungus residue based on this microbial composition can improve the physical and chemical properties of soil in ginseng-growing areas, reduce pesticide residues and allelochemical content in the soil, decrease ginseng disease incidence, and increase key production indicators such as fresh weight and root length of ginseng under continuous cropping, as well as ginsenoside content; it can also increase the thousand-seed weight, seedling survival rate, and dry weight of ginseng seeds.

The utility model discloses a triclosan preparation device relates to triclosan production technical field, including first reactor, the inlet of first reactor is respectively through pipeline intercommunication with 2,4 - dichlorophenol jar, sodium hydroxide solution jar, xylene jar I and tetrabutyl ammonium bromide jar, the outlet of first reactor is through pipeline intercommunication with second reactor, the inlet of second reactor is respectively through pipeline intercommunication with 2 - chloro - 5 - nitrobenzene methyl ether jar, dilute hydrochloric acid solution jar, ZnCl2 - Al2O3 solid acid jar, nano TiO2 jar and xylene jar II, the outlet of second reactor is through pipeline intercommunication with third reactor, the inlet of third reactor is through pipeline intercommunication with acetic acid jar, the top gas phase export of third reactor is through pipeline intercommunication with first condenser, and the outlet of first condenser is through pipeline intercommunication with crude product jar, improves the yield of product.

The invention discloses a modified bismaleimide composite material as well as a preparation method and application thereof, and belongs to the technical field of bismaleimide materials. The preparation method comprises the following steps: reacting a fluorenyl structure-containing reagent, 4, 4 '-4-dichlorobenzophenone and 4-chloronitrobenzene under the action of a catalyst, and then adding ferric trichloride and N2H4.H2O for a reduction reaction; maleic anhydride and acetic anhydride are sequentially added for a reaction, and modified bismaleimide resin is obtained; the modified bismaleimide resin and the bismaleimide resin are mixed, and prepreg resin is obtained; and coating prepreg resin on release paper, covering fiber cloth for hot-pressing impregnation, cutting, paving in a mold, and curing and forming, so as to obtain the product. The invention further discloses the modified bismaleimide composite material prepared by the method and application of the modified bismaleimide composite material. The problems that existing bismaleimide is high in brittleness, and the impact resistance and the heat resistance cannot be achieved at the same time can be solved.

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

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

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 provides a method for preparing 2-chloro-3-nitrobenzoic acid through diazotization by using a phase transfer catalyst, and belongs to the field of pharmaceutical chemicals. The method comprises the following steps: mixing 2-amino-3-nitrobenzoic acid, acid, nitrite, a phase transfer catalyst (selected from any one of polyethylene glycol, tetramethylammonium chloride, TBAB and 18-crown-6) and solvent water according to a certain proportion, and reacting at 0-25 DEG C to obtain a first reaction solution containing diazonium salt; mixing and reacting the first reaction liquid with hydrochloric acid and a catalyst (copper or cuprous chloride) at 0-10 DEG C, and performing post-treatment to obtain 2-chloro-3-nitrobenzoic acid. The method solves the problem of low reaction efficiency caused by difficult dissolution of 2-amino-3-nitrobenzoic acid through the phase transfer catalyst, has the characteristics of simple operation steps, low cost, high yield (more than 85%) and high purity (more than 99%), and is suitable for industrial large-scale production.

The application belongs to the technical field of fine chemical industry, and particularly relates to a pipeline reactor and a device and method for preparing 3,5-dichloronitrobenzene. The pipeline reactor comprises a reactor main body which is a pipeline structure arranged in a vertical direction; a feed inlet and an exhaust outlet are arranged at the upper part of the reactor main body, and a liquid return inlet and a liquid discharge outlet are arranged at the lower part of the reactor main body; reactant materials enter the reactor main body from the upper part of the reactor main body through the feed inlet; the gas generated in the reaction process is discharged through the exhaust outlet, and then is subjected to cooling and gas-liquid separation treatment; the liquid obtained through the gas-liquid separation treatment is injected into the reactor main body again through the liquid return inlet; and the reaction completion liquid after the reaction is completed is discharged from the reactor main body through the liquid discharge outlet. The pipeline reactor and the device and method for preparing 3,5-dichloronitrobenzene have the advantages of high production efficiency, good safety, and continuous production.

The invention relates to a method for green and efficient preparation of 3-amino-4 '-nitrodiphenyl ether, and belongs to the technical field of organic synthesis. The method for preparing 3-amino-4 '-nitrodiphenyl ether comprises the following steps: S1, reacting a hydrogen bond acceptor and a hydrogen bond donor under a heating condition to prepare DES; and S2, adding parachloronitrobenzene and m-aminophenol into the DES prepared in the step S1, heating to carry out etherification reaction, and carrying out water washing and solid-liquid separation treatment on the reaction liquid to obtain the 3-amino-4 '-nitrodiphenyl ether product. The hydrogen bond receptor is at least one of choline chloride and betaine; the hydrogen bond donor is at least one of polyethylene glycol, urea and thiourea. The method for preparing the 3-amino-4 '-nitrodiphenyl ether has the advantages of mild reaction conditions, environmental friendliness and the like, and the 3-amino-4'-nitrodiphenyl ether product with high yield and high purity can be directly obtained.

The invention discloses a preparation method of a 2-fluoro-3-nitrobenzoic acid compound, and relates to the technical field of organic chemical synthesis, 3-nitro-salicylonitrile, phosphorus oxychloride, triethylamine and potassium fluoride are used as raw materials, 3-nitro-salicylonitrile and phosphorus oxychloride are mixed, triethylamine is dropwise added to synthesize 2-chloro-3-nitrobenzonitrile, the 2-chloro-3-nitrobenzonitrile reacts with a fluorinating agent, and the 2-fluoro-3-nitrobenzoic acid compound is obtained. According to the method, chloridion is converted into fluorine ions, 2-fluorine-3-nitrobenzonitrile is obtained, pure 2-fluorine-3-nitrobenzonitrile is obtained through distillation and purification, and high-content 2-fluorine-3-nitrobenzoic acid is obtained through hydrolysis of a 30-60% sulfuric acid aqueous solution. The preparation method of the 2-fluoro-3-nitrobenzonitrile compound is high in yield, high in efficiency, high in safety, economical and practical.

The invention relates to a dichloronitrobenzene hydrogenation catalyst as well as a preparation method and application thereof, and the preparation method of the dichloronitrobenzene hydrogenation catalyst comprises the following steps: (1) adding a precipitator into a metal salt solution to prepare a metal oxide carrier; adding tetraethoxysilane into the reaction liquid, aging, carrying out solid-liquid separation to obtain a solid phase, and carrying out drying and first calcination to obtain a composite oxide carrier; and (2) mixing a platinum source solution, a reducing agent, distilled water and the composite oxide carrier obtained in the step (1), carrying out solid-liquid separation, washing a solid phase with distilled water, and carrying out drying and secondary calcination on the obtained solid phase to obtain the dichloronitrobenzene hydrogenation catalyst. The metal platinum is loaded on the metal oxide-silicon dioxide composite carrier, so that the selectivity of the catalyst is remarkably improved, and the content of dechlorination byproducts in dichloronitrobenzene hydrogenation reaction is greatly reduced.

The invention provides a continuous production method of 2, 4-dichloronitrobenzene, which belongs to the technical field of fine chemical intermediates, and comprises the following steps: S1, dropwise adding nitric acid into sulfuric acid, and uniformly mixing to form a mixed acid solution; s2, respectively feeding 1, 3-dichlorobenzene and part of the mixed acid solution into the primary reactor, controlling the reaction temperature and the material retention time, and feeding discharged materials into a secondary reactor; meanwhile, pumping the residual mixed acid solution into the second-stage reactor, controlling the reaction temperature and the material retention time, and continuously feeding the discharged material into a third-stage reactor; controlling the reaction temperature and the material retention time in the third-stage reactor; and S3, carrying out standing layering on the discharged material obtained from the discharge port of the third-stage reactor, and collecting an organic phase, thereby obtaining the 2, 4-dichloronitrobenzene. According to the method, the continuous nitration reaction is realized, the energy consumption is reduced, the online liquid holdup of the material is low, the reaction is safe and easy to control, the reactant loss and the byproduct generation amount are reduced, and the purity and the yield of the target product are improved.

This invention relates to a method for synthesizing hydroquinone, a pharmaceutical and chemical intermediate. The invention comprises the following steps: (1) hydrolysis of p-chloronitrobenzene in an alkaline solution, adjusting the pH to 5-6 with acid to obtain p-nitrophenol; (2) reduction of p-nitrophenol and hydrogen under catalytic conditions to obtain p-aminophenol; (3) diazotization of a dilute acid solution of p-aminophenol with sodium nitrite; the reaction solution reacts with a dilute acid solution used for hydrolysis to obtain hydroquinone; after the reaction, solvent extraction is performed, followed by concentration, centrifugation, and drying. The reactions are carried out in a microreactor system. Compared with existing hydroquinone production processes, this invention uses continuous flow technology for continuous production, greatly improving production efficiency and saving production costs. It solves the problems of high levels of waste, low selectivity, and high purification costs associated with traditional batch processes. Furthermore, the continuous flow production process has a lower scale-up effect, easier process control, and is suitable for industrial production.