135 results about "Methylaniline" patented technology

Provided herein are polymorphs and crystalline forms of 2-fluoro-5-((5S,5aS,6S,9R)-1-fluoro-12-(((2R,7aS)-2-fluorotetrahydro-1H-pyrrolizin-7a(5H)-yl)methoxy)-5-methyl-5a,6,7,8,9,10-hexahydro-5H-4-oxa-3,10a,11,13,14-pentaaza-6,9-methanonaphtho[1,8-ab]heptalen-2-yl)-3-methyl-4-(trifluoromethyl)aniline (Compound of Formula (I)), pharmaceutical compositions thereof, and methods of their use, for example, in the treatment of cancer. Also provided herein are synthetic processes for the manufacture of a compound of Formula (I) (i.e., 2-fluoro-5-((5S,5aS,6S,9R)-1-fluoro-12-(((2R,7aS)-2-fluorotetrahydro-1H-pyrrolizin-7a(5H)-yl)methoxy)-5-methyl-5a,6,7,8,9,10-hexahydro-5H-4-oxa-3,10a,11,13,14-pentaaza-6,9-methanonaphtho[1,8-ab]heptalen-2-yl)-3-methyl-4-(trifluoromethyl)aniline). Also provided are compounds useful in its synthesis (e.g., those of Formulae (A), (B), (By), and (H)) and synthetic processes directed thereto.

The invention relates to a method and a system for synthesizing N-methylaniline and co-producing N, N-dimethylaniline by a gas phase method, and belongs to the technical field of chemical engineering. The system comprises a raw material gasification unit, a reaction unit, a separation and rectification unit and a hydrogen recovery unit which are connected through pipelines. The method comprises the following steps of: firstly, mainly synthesizing N-methylaniline from raw materials aniline and part of methanol in a first-methylaniline reactor, then partially or completely feeding first-methylaniline reaction gas into a second-methylaniline reactor, adding methanol steam, and further reacting to generate N, N-dimethylaniline. And after the product gas is subjected to heat exchange energy recovery, a liquid phase and a gas phase respectively enter the separation and rectification unit and the hydrogen recovery unit. The purification of N-methylaniline and N, N-dimethylaniline and the recovery of byproduct hydrogen are realized. The yield of N, N-dimethylaniline (in terms of aniline) can be adjusted in a range of 5-30% by adjusting reaction conditions and a feeding ratio.

The invention provides a catalyst for synthesizing N-methylaniline and a preparation method thereof, the catalyst comprises an active component, a carrier and an auxiliary agent, the active component comprises oxygen-containing compounds of copper, zinc and chromium, the carrier is gamma-alumina subjected to surface hydroxylation treatment, and the auxiliary agent is a cerium-molybdenum bimetallic alloy. The preparation method comprises the following steps: loading the active component on the hydroxylation carrier through ultrasonic impregnation, drying, further loading the cerium-molybdenum auxiliary agent, and carrying out reduction alloying and roasting activation to form the composite catalyst. The catalyst is a regular cylinder, has the diameter of 4-6mm and the length of 4-6mm, has an optimized pore structure and surface properties, and is suitable for methylation reaction of aniline and methanol. According to the method, the dispersity of active components is improved through modified chromic oxide, the mass transfer efficiency is enhanced through a hydroxylation carrier, the synergistic catalysis effect of cerium-molybdenum alloy is combined, the reaction activity and selectivity are remarkably improved, meanwhile, side reactions are inhibited, the stability is enhanced, and the method can be widely applied to industrial production of N-methylaniline.

The invention discloses a method for extracting and separating N-methylaniline and N, N-dimethylaniline, and relates to the technical field of organic compound separation.The method comprises the steps that a reaction product of aniline and methyl alcohol is taken and fed into an adsorption refiner to be adsorbed, and a mixture A is obtained; feeding the mixture A into a light component removal tower for light component removal, collecting at the top of the light component removal tower to obtain light components, feeding the light component removal tower into a heavy component removal tower for heavy component removal, and collecting at the top of the heavy component removal tower to obtain a mixture B; taking the mixture B, feeding from the middle part of an extractive distillation tower, taking an extracting agent, feeding from the upper part of the extractive distillation tower, and performing extractive distillation; collecting the N, N-dimethylaniline at the top of the extractive distillation tower to obtain N, N-dimethylaniline, and collecting the N, N-dimethylaniline at the bottom of the extractive distillation tower to obtain an N-methylaniline mixed solution; feeding the N-methylaniline mixed solution into a desorption tower for desorption; collecting at the top of the desorption tower to obtain N-methylaniline, and collecting at the bottom of the desorption tower to obtain the extracting agent.

The invention discloses a method for synthesizing a chlorfenapyr bisamide intermediate by a one-pot method, which comprises the following steps: by taking aniline as an initial raw material, reacting the aniline with 2-bromoheptafluoropropane under the action of a catalyst and an acid-binding agent to generate 4-heptafluoroisopropylaniline, distilling to recover excessive 2-bromoheptafluoropropane after the aniline is completely converted, and separating the 2-bromoheptafluoropropane from the 4-heptafluoroisopropylaniline to obtain the chlorfenapyr bisamide intermediate. Adding bromotrifluoromethane into the reaction liquid to react to obtain 2-trifluoromethyl-4-(heptafluoroisopropyl) aniline, then carrying out oxidation-reduction reaction on the dropped hydrogen peroxide and excessive sodium hydrosulfite, and after the sodium hydrosulfite is completely consumed, reacting to obtain 2-trifluoromethyl-4-(heptafluoroisopropyl) aniline; and carrying out benzene ring bromination reaction on dropwise added hydrogen peroxide, the brominating agent in the reaction liquid and the 2-trifluoromethyl-4-(heptafluoroisopropyl) aniline to obtain the 2-bromo-4-(heptafluoroisopropyl)-6-(trifluoromethyl) aniline, wherein the brominating agent in the reaction liquid and the 2-trifluoromethyl-4-(heptafluoroisopropyl)-6-(trifluoromethyl) aniline are subjected to benzene ring bromination reaction. The method is simple in process, high in yield, low in raw material cost and suitable for industrial production.

The invention belongs to the technical field of organic synthetic chemistry, and particularly relates to a synthesis process of N-methylaniline. By adopting the special biomass porous carbon loaded nickel-copper bimetallic catalyst, the selectivity and the conversion rate of the reaction are improved, and the generation of byproducts is reduced, so that the burden of subsequent separation is reduced, the utilization rate of the raw materials is improved, and the yield is increased by introducing the micro-channel reactor and combining a microwave heating technology. Compared with the prior art, the method has the advantages that the mixing efficiency and the heat mass transfer rate of materials are improved, the reaction time is shortened, in the separation and purification process, a membrane separation and rectification combined technology and an efficient phase splitter are adopted, salt water is not needed, salt-containing wastewater is avoided, meanwhile, the recovery efficiency of methanol and aniline is improved, and cyclic utilization of a solvent is achieved. The whole process reduces the energy consumption, improves the production efficiency, reduces the emission of pollutants and meets the requirements of green chemistry through waste heat recovery, heating mode optimization and separation process.

The invention relates to the technical field of catalysts for synthesizing N-methylaniline, in particular to a basic cupric carbonate based composite catalyst for synthesizing N-methylaniline through N methylation of aniline and a preparation method of the basic cupric carbonate based composite catalyst. The selectivity of a conventional copper-based catalyst to N-methylaniline in a reaction for preparing N-methylaniline through N methylation of aniline is difficult to reach 90% or above. Aiming at the technical problem, the invention provides the basic cupric carbonate-based composite catalyst for synthesizing N-methylaniline through N methylation of aniline, the structural formula of the basic cupric carbonate-based composite catalyst can be represented as CuM (OH) x (CO3) y, M in the structural general formula comprises one or more of metal elements of zinc, aluminum, chromium, lanthanum and manganese, and by optimizing the composition of the metal elements in the catalyst and the pH value in the coprecipitation process, the N-methylaniline can be synthesized. The basic cupric carbonate-based composite catalyst with a relatively good catalytic effect is obtained, and obvious inactivation is not found when the basic cupric carbonate-based composite catalyst can stably and continuously run for 1000 hours under the condition of keeping a relatively high N-methylaniline yield.

The application provides a process and equipment for removing m-methylaniline and indole in coking nanofiltration concentrated water, a catalyst and a preparation method thereof, and the water quality of the coking nanofiltration concentrated water is as follows: conductivity 21300-34560 muS / cm, sulfate ion 567-1340 mg / L, m-methylaniline 45-78 mu g / L, and indole 23-39 mu g / L; the process comprises the following treatment steps: the coking nanofiltration concentrated water enters the ozone catalytic tower from the bottom of the tower and flows out from bottom to top, and the ozone catalytic tower is internally provided with a modified peanut shell biochar catalyst; after the ozone catalytic reaction, the water quality of the coking nanofiltration concentrated water is as follows: conductivity 21300-34560 muS / cm, sulfate ion 567-1340 mg / L, m-methylaniline 3-7 mu g / L, and indole 1-6 mu g / L.

The application discloses a catalyst for preparing methylaniline and a preparation method and application thereof, and belongs to the technical field of catalysts. The catalyst is prepared by modifying an activated carbon carrier with zirconium, cerium or nickel, treating the carrier with high-temperature nitrogen, loading active components Pd and pH-responsive polymers, solving the problems of low dispersion of the active components, easy poisoning and activity attenuation, and having good pH responsiveness and environmental adaptability. The preparation method optimizes a carrier modification process, adopts an impregnation method combined with timed stirring, controls reaction parameters, improves catalyst performance, realizes high selectivity and high yield of methylaniline, and has the advantages of high selectivity of the catalyst for methylaniline, inhibition of side reactions, adoption of a fixed bed reactor, simplification of operation, reduction of safety hazards, efficient reaction at a lower reaction temperature and pressure, and reduction of energy consumption and production cost.

The present invention relates to a method for separating and purifying a pesticide chemical product, in particular to a method for improving the quality of 2,6-dichloro-4-trifluoromethylaniline. First, a composite protective agent is added to the crude product of 2,6-dichloro-4-trifluoromethylaniline, and after mixing evenly, it is sent to a rectification device for vacuum rectification. The refined product of 2,6-dichloro-4-trifluoromethylaniline is obtained by rectification. The composite protective agent includes metal fluoride and amine compounds, which can inhibit the dechlorination of 2,6-dichloro-4-trifluoromethylaniline, greatly reduce the generation of impurities, and greatly improve the rectification yield of 2,6-dichloro-4-trifluoromethylaniline.

The invention discloses a method for reducing by-product N-methylaniline in RT base condensation liquid. According to the method, potassium hydroxide modified activated carbon is added in condensation reaction. The potassium hydroxide modified activated carbon greatly reduces the generation of a by-product N-methylaniline in a condensation reaction, reduces the absorption of carbon dioxide in air by system materials, slows down the increase of tetramethyl carbonate, prolongs the catalytic life of tetramethyl ammonium hydroxide, saves the cost of raw materials, and has a good application prospect.

The invention provides a synthesis method of atavapam, which comprises the following steps: carrying out nucleophilic addition-elimination reaction on commercially available raw materials and 4-methyl-3-trifluoromethylaniline under alkaline conditions, carrying out Suzuki coupling reaction under the action of a catalyst, carrying out pressurized hydrogenation, and carrying out chiral resolution, thereby obtaining the atavapam. And condensing with 2-fluoro-6-methyl benzoyl chloride under an alkaline condition, and further removing a Boc protecting group under an acidic condition to finish synthesis of the atavapam. According to the invention, a convergent synthesis process is adopted, tedious synthesis steps in the original process are shortened, and post-treatment is simpler and more controllable.

The present invention provides a method and system for co-producing N-methylaniline and N-methylindole. The method comprises: a first Cu-based catalyst catalyzes a first reaction between aniline and methanol to obtain a first gaseous mixed system containing N-methylaniline; ethylene glycol is introduced into the first gaseous mixed system, and part of the N-methylaniline and ethylene glycol in the first gaseous mixed system undergo a second reaction under the catalysis of a second Cu-based catalyst to be converted into N-methylindole, and finally a second gaseous mixed system containing N-methylaniline and N-methylindole is obtained; the second gaseous mixed system is condensed, flashed and distilled to separate N-methylaniline and N-methylindole. In the co-production method provided by the present invention, by means of a two-stage reaction, not only N-methylaniline is synthesized with high efficiency and low cost, but also co-production of N-methylaniline and N-methylindole is achieved.

The invention relates to the technical field of zinc-silver batteries, in particular to a zinc-silver battery electrolyte additive, a zinc-silver battery electrolyte and a zinc-silver secondary battery. A trace amount of negatively-charged surfactant N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt is added into the traditional KOH electrolyte of the zinc-silver secondary battery, and the problem of deformation of a zinc negative electrode caused by the existence of a free-state charge-discharge intermediate product Zn (OH) 4 < 2-> is inhibited by utilizing specific adsorption of amphoteric molecules and a negatively-charged functional group. The additive not only can stabilize the zinc negative electrode structure and improve the cycle performance of the zinc-silver battery, but also can enable the active substances in the zinc-silver battery to give full play to the capacity, and prolongs the service life of the zinc-silver secondary battery for repeated and stable discharge and energy supply.

The invention discloses a preparation process of 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid, and relates to the technical field of preparation of inorganic compounds. The invention relates to a preparation process of 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid, which comprises the following steps: reacting 3-chloro-2-methylaniline with hydrochloric acid and sodium methyl mercaptide to form an intermediate C1, reacting with acetyl chloride, catalyzing with anhydrous aluminum trichloride to form an intermediate C2, reacting with hydrogen peroxide and sodium hypochlorite to form an intermediate C4, and reacting with sodium chloride to form the 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid. The 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid is obtained after the reaction is completed.

The application relates to the technical field of medicines, in particular to a preparation process of a Tucatinib intermediate 4-([1,2,4]triazolo[1,5-a]pyridin-7-yloxy)-3-methylaniline, which comprises the following steps: step 1: under a nitrogen atmosphere, a substitution reaction is carried out on a compound B and a compound C in a base and an organic solvent system to obtain a compound D; step 2: the compound D is added into a reduction catalytic solution system protected by nitrogen, after 8-30h of reaction at 70-120 DEG C, TLC tracking is carried out until the reaction is completed, 2-8 times the volume of the compound D is added into water, post-treatment and purification are carried out, and the compound A is obtained; wherein the reduction catalytic solution system comprises a reducing agent, a catalyst and an inorganic acid, the reducing agent comprises a reducing phosphoric acid, and the catalyst comprises iodine or a metal salt of iodine. The preparation process of the Tucatinib intermediate 4-([1,2,4]triazolo[1,5-a]pyridin-7-yloxy)-3-methylaniline in the application has mild reaction conditions, high product yield and high purity, the preparation process is environment-friendly, and can be used for industrial production.

The invention relates to the technical field of harmful substance detection, in particular to a three-channel colorimetric sensor for simultaneously detecting aflatoxin and a precursor thereof as well as a preparation method and application of the three-channel colorimetric sensor. According to the method, COFFe / NiP-Ph is utilized for catalyzing 3, 3 ', 5, 5'-tetramethylbenzidine (TMB) to be oxidized to generate blue oxTMB, o-phenylenediamine (OPD) is utilized for generating yellow oxOPD, and then the aflatoxin and the precursor thereof are detected through a three-channel colorimetric sensor. Purple ox4-AT is generated by using a mixture of N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium and 4-aminoantipyrine (4-AT), so that the colorimetric response is realized in a short time. The preparation method of the COFFe / NiP-Ph nano enzyme comprises the following steps: 1, a synthesis process of Fe-TAPP; 2, synthesis of Ni-TAPP is carried out; and 3, synthesizing the iron / nickel porphyrin covalent organic framework. The colorimetric sensor can be prepared into a detection reagent or a kit so as to realize qualitative and quantitative detection of aflatoxin and a precursor thereof in a sample to be detected. The detection method is simple and convenient to operate, and complex pretreatment on a to-be-detected sample is not needed; the detection cost is low, the detection is quick, and the requirement on a detection instrument is low.

The invention relates to the technical field of carbon black detection, in particular to a purity analysis method of carbon black prepared from organic hazardous waste. The purity analysis method comprises the following steps: S1, mixing carbon black with an organic amine solution to obtain a mixture; s2, mixing the mixture with an organic solvent, performing centrifugal filtration to obtain filtrate, and measuring the light transmittance; the organic amine comprises a mixed solvent of piperidine and N-methylaniline. The carbon black is prepared by the following method: (1) carrying out dehydration pretreatment on the organic hazardous waste, and crushing to obtain a particle sample; (2) pyrolyzing the particle sample under the inert gas condition at the pyrolysis temperature of 1100-1400 DEG C, separating out carbon black generated in the pyrolysis process along with a gas-phase product, and filtering and collecting by a filter membrane; and (3) cleaning the filter membrane with an organic solvent, filtering, and drying to obtain the carbon black. The purity analysis method is more accurate, and the analysis result can better represent the purity of the carbon black.

The invention relates to the technical field of chemical monitoring, in particular to an N-methylaniline impurity online spectrum monitoring device which comprises a bottom rack, a plurality of glass boxes are evenly arranged on the bottom rack in the length direction, the glass boxes sequentially have different deflection angles, and the deflection angle difference values of the adjacent glass boxes are equal; by arranging the multi-angle deflection glass box, static and multi-angle static monitoring of N-methylaniline is realized, spectral characteristics of impurities in different directions can be effectively captured, and slow rotation of the glass box further drives the internal N-methylaniline to change angles, so that a light source can fully irradiate, and the detection accuracy is improved. Impurities possibly hidden due to local gathering are repeatedly exposed in dynamic rotation, a monitoring blind area is eliminated, the comprehensiveness of impurity detection is remarkably enhanced through the steps, and the accuracy of a monitoring result can be greatly improved especially for trace impurities which are not evenly distributed.

This invention relates to the field of asphalt technology and discloses a high-adhesion asphalt anti-stripping agent and its preparation method; including the following steps: Step 1: Add amino-branched titanium dioxide to N-methylaniline and mix evenly to obtain a polyamine complex; Step 2: Mix terpene phenolic resin, methyl phenyl silicone resin, and additives evenly, add the polyamine complex and calcium hydroxide, and mix evenly to obtain a high-adhesion asphalt anti-stripping agent.

The preparation method comprises the following steps: step 1, first interfacial polymerization: immersing a polysulfone support membrane into a polyamine water phase solution, taking out the polysulfone support membrane, removing a solvent, immersing the polysulfone support membrane into an acyl chloride A part hydrolyzed oil phase solution, and carrying out first interfacial polymerization reaction, so as to obtain a polysulfone membrane; a nascent state reverse osmosis membrane is obtained; step 2, secondary interfacial polymerization: removing unreacted acyl chloride from the nascent state reverse osmosis membrane, then immersing the nascent state reverse osmosis membrane into an oil phase solution of acyl chloride B to carry out secondary interfacial polymerization reaction, and then carrying out heat treatment to obtain a reverse osmosis membrane semi-finished product; and step 3, third interfacial polymerization: immersing the semi-finished reverse osmosis membrane product into an oil phase solution of o-methylaniline, carrying out third interfacial polymerization, and carrying out heat treatment again to obtain the ultra-high-desalination and anti-oxidation reverse osmosis membrane. Under the condition of ensuring that the water flux is not greatly reduced, the ultra-high desalination rate of the reverse osmosis membrane is realized, and the service life of the membrane is prolonged.

The invention discloses a Schiff base compound generated by condensation of 1-pyrenecarboxaldehyde and 4-(1, 2, 4-triazole-1-yl methyl) aniline as well as a preparation method and application of the Schiff base compound. The Schiff base compound has certain fluorescence and anti-DPPH free radical activity, and has potential application value in preparation of fluorescent materials and antioxidants.

The invention belongs to the technical field of fluorescent probes, and particularly relates to a near-infrared fluorescent probe compound as well as a preparation method and application thereof. 4-bromo-N, N-dimethylaniline, 5-formyl thiophene-2-boric acid and paeonol are adopted as reaction substrates, and a novel near-infrared fluorescent probe compound # imgabs0 is prepared through a simple two-step chemical reaction. The preparation method is short in reaction route, high in synthesis efficiency and mild in reaction condition; the method is simple and convenient to operate, few in side reaction, high in product purity, convenient to separate and purify and suitable for gram-level large-scale preparation; the obtained product has a very good application prospect in the field of biological medicines, and especially has a relatively good brain in-situ imaging effect.

The present application relates to the technical field of clay stabilizers, and in particular to a kind of oligomeric cationic quaternary ammonium salt clay stabilizer and its preparation method. The preparation method of the oligomeric cationic quaternary ammonium salt clay stabilizer of the present application comprises the following steps: N-methylaniline and epichlorohydrin react under a first reaction condition to generate a target monomer; the target monomer undergoes a self-polymerization reaction under a second reaction condition to generate a target polymer; the target polymer undergoes a hydrolysis reaction to generate a crude product; the crude product is subjected to an impurity removal treatment to obtain an oligomeric cationic quaternary ammonium salt clay stabilizer. The anti-swelling performance and water washing resistance of the oligomeric cationic quaternary ammonium salt clay stabilizer of the present application are significantly improved, and the preparation mechanism is clear, the reaction conditions are simple, and the post-processing operation is simple, and it is easy to scale up production.

The application belongs to the technical field of organic synthesis, and particularly relates to a preparation method of 4-amino-2-methylbenzoic acid, and more particularly relates to a preparation method of 4-amino-2-methylbenzoic acid as a raw material of a tolvaptan intermediate, wherein 3-methylaniline is used as a raw material to prepare 3-methylacetanilide with an acylating agent, the 3-methylacetanilide is subjected to Friedel-Crafts acylation with oxalyl chloride under a Lewis acid catalytic system to prepare 4-acetylamino-2-methylbenzoic acid, and finally, the 4-acetylamino-2-methylbenzoic acid is deprotected under alkaline conditions, and then acidified to obtain the target compound 4-amino-2-methylbenzoic acid, wherein the raw material used in the preparation method is cheap and easy to obtain, the production equipment has low requirements, the process condition is simple, the safety factor is high, no ammonia nitrogen and other three wastes are generated, the cost is low, and the industrialized production is easy to implement.

The present application discloses a method for detecting N,N-dimethylaniline, comprising the following steps: preparing a PPY+N-MWCNT+MoS2 composite extraction head; performing headspace extraction of N,N-dimethylaniline with the composite extraction head; constructing a gas chromatography-mass spectrometry (GC-MS), and using the extraction head to detect N,N-dimethylaniline. The beneficial effects are as follows: The PPY+N-MWCNT+MoS2 composite extraction head has better extraction efficiency and mechanical stability for N,N-dimethylaniline. Applying the method of the present application to the detection of N,N-dimethylaniline in actual samples has good sensitivity and practicability.

The present invention relates to a preparation method of a No. II neutralizing agent, comprising the following steps: step 1) adding N-methylaniline to an alkaline aqueous solution and mixing to obtain an N-methylaniline mixed solution; step 2) adding bis(trichloromethyl)carbonic acid to the N-methylaniline mixed solution and stirring the reaction; maintaining the reaction temperature less than 105°C by controlling the addition rate of bis(trichloromethyl)carbonic acid during the reaction to obtain a reaction product; step 3) performing solid-liquid separation on the reaction product to obtain No. I neutralizing agent. The present invention uses solid triphosgene as a raw material and adopts a one-pot method to prepare No. II neutralizing agent. The preparation process is stable. When solid phosgene is 105% to 110% of the theoretical feed, the reaction yield can reach more than 95%. At the same time, the entire preparation process is safe, stable, and less polluting during the entire reaction process.

The application provides a preparation method of 4,4'-diamino-2,2'-dimethylbiphenyl, which comprises the following steps: under the protection of a protective gas, m-methylaniline is reacted in a mixed solvent of water and an organic solvent under the catalysis of potassium ferricyanide and an alkali to obtain 4,4'-diamino-2,2'-dimethylbiphenyl shown in formula I. The m-methylaniline is used for oxidative coupling to obtain 4,4'-diamino-2,2'-dimethylbiphenyl, the reaction steps are short, the selectivity is higher, the reaction yield is high, and the cost is lower, so that the preparation method is novel, the selectivity is good, the overall preparation cost is low, and the yield is high.

The invention discloses a preparation method of 2, 6-dichloro-4-trifluoromethylaniline, and relates to the technical field of organic chemistry, the preparation method of 2, 6-dichloro-4-trifluoromethylaniline comprises the following steps: S1, performing a reaction on chlorobenzotrifluoride and a derivative thereof with DES to obtain an ammonification reaction solution; s2, adding a sodium hydroxide aqueous solution into the ammoniation reaction solution obtained in the step S1 to promote the ammoniation reaction solution to generate a hydrolysis reaction, so as to obtain a hydrolysis solution of which the main component is an intermediate 3-chloro-4-aminotrifluorotoluene; and S3, sequentially adding concentrated hydrochloric acid and a hydrogen peroxide solution into the hydrolysis solution with the intermediate 3-chloro-4-aminotrifluorotoluene as the main component obtained in the step S2 to promote chlorination reaction, and then performing post-treatment to obtain a target product. According to the preparation method, the target product can be effectively prepared and synthesized under the condition that the reaction temperature is lower than that of a traditional process under the normal pressure condition, the danger coefficient and the operation difficulty of the reaction are remarkably reduced, and the preparation method is a safe, efficient, environment-friendly and economical synthesis preparation method.

The application provides a low-yellowing fluorine-free semi-alicyclic polyimide composition and a preparation method thereof, and relates to the technical field of polyimide preparation.The semi-alicyclic polyimide composition is prepared by polymerization reaction of diamine and dianhydride; the diamine comprises first diamine and second diamine; the first diamine is 4,4'-diamino diphenyl ether-2,2'-disulfonic acid and / or 4-(4-aminophenoxy)-2,6-dimethyl aniline; the second diamine is 4,4'-diamino dicyclohexyl methane and / or 3,3'-dimethyl-4,4'-diamino dicyclohexyl methane; and the dianhydride is fluorine-free dianhydride. The semi-alicyclic polyimide composition prepared by the application significantly improves the optical performance of the polyimide film prepared therefrom, and the anti-yellowing effect is significantly improved.