491 results about "Chloromethane" patented technology

The invention relates to the technical field of repair materials, and particularly discloses an extracellular matrix fiber material as well as a preparation method and application thereof. The invention discloses a preparation method of an extracellular matrix fiber material. The preparation method comprises the following steps: taking animal tissues, and carrying out virus inactivation, decellularization and antigen removal, degreasing, drying, grinding and sterilization; the decellularization and antigen removal method comprises the following specific steps: sequentially soaking a sample with a surfactant solution for h; then, soaking treatment is carried out by adopting a salt-alkali solution which contains 0.05-3 mol / L of salt and has the pH value of 8-11; then carrying out soaking treatment by adopting a 0.1-1wt% enzyme solution; and in degreasing, one or more of normal hexane, trichloromethane, dichloromethane, methanol, ethanol, acetone, diethyl ether and ethyl acetate are used for soaking the sample. According to the technical scheme, the ECM powder particle material with high growth factor content is prepared.

The invention relates to the technical field of synthesis of chemical products, in particular to a synthesis method of acryloyloxyethyl trimethyl ammonium chloride. According to the method, a one-pot reaction system is adopted, ethyl acrylate and N, N-dimethylaminoethanol are taken as raw materials and are subjected to quaternization reaction with chloromethane under an alkaline condition, and efficient conversion is realized through the synergistic effect of a composite catalytic system and a polymerization inhibitor. The composite catalyst is constructed by compounding magnetic nanoparticles and a metal organic framework material, forms a multilevel structure through titanate crosslinking, and has high catalytic activity and magnetic separation and recovery characteristics. The method simplifies the traditional step-by-step process, has the advantages of simple and convenient one-pot operation, recyclable catalyst, high raw material utilization rate, environmental friendliness and the like, and is suitable for large-scale preparation of acryloyloxyethyl trimethyl ammonium chloride.

The invention belongs to the technical field of high polymer material detection, and discloses a quantitative detection method for potassium perfluorobutanesulfonate in a high polymer material and application of the quantitative detection method. According to the method, trichloromethane reflux extraction and methanol precipitation are adopted as pretreatment, and specific liquid chromatography-tandem mass spectrometry detection conditions are matched, so that excellent recovery rate and extremely low limit of quantitation are obtained, and the determination requirement of potassium perfluorobutanesulfonate in a high polymer material is met. In addition, the invention further provides a detection method for simultaneously detecting the content of the potassium perfluorobutanesulfonate and the content of the polytetrafluoroethylene in the high polymer material, the content of perfluorine in a sample is detected firstly, then the content of the potassium perfluorobutanesulfonate is detected by adopting the quantitative detection method, and the content of the polytetrafluoroethylene is calculated through the content of the potassium perfluorobutanesulfonate and the content of the polytetrafluoroethylene. The method provided by the invention is simple and easy to implement, high in accuracy and good in reproducibility.

The invention discloses a crystal compound, a preparation method thereof and application of the crystal compound in X-ray detection, imaging and anti-counterfeiting encryption, and belongs to the technical field of crystals. The molecular formula of the crystal compound is [Cu (totp) (CH3CN) 3] [Cu2I3 (totp) (PN)]. (CH3CN), wherein totp is tris (o-tolyl) phosphine; and PN is diphenyl-2-pyridine phosphine. The crystal compound disclosed by the invention is simple in preparation method, and has the characteristics of large mass attenuation coefficient of X-ray energy, high light yield and low detection limit when being used as a material of an X-ray detector. The compound also has the characteristic of structural transformation in solvents such as methanol, ethanol, acetone, dichloromethane, tetrahydrofuran and the like, and meanwhile, the conversion of luminescence color under the excitation of 365nm ultraviolet light and X rays is accompanied. The material can be applied to the aspects of scintillator materials, room-temperature X-ray radiation indirect detection materials, radiation detection dosimeters, X-ray scintillator medical imaging, anti-counterfeiting encryption and the like.

The invention relates to the technical field of waste gas treatment, and particularly discloses waste gas treatment liquid for treating large-air-volume low-concentration waste gas through a water-based method. The waste gas treatment liquid for treating the large-air-volume low-concentration waste gas through the water-based method comprises a surfactant, a defoaming agent, a dissolution accelerant and water. Wherein the surfactant can be selected from any one or more of polyoxyethylene alkyl ether, polyoxyethylene alkyl ether and polyoxyethylene fatty acid ester; the dissolution accelerant can be selected from any one or more of ethylene glycol monobutyl ether, diethylene glycol monobutyl ether and triethylene glycol monobutyl ether; the defoaming agent is any one or more of butanol, dimethyl silicone oil, silicone and polyether modified polysiloxane. When the waste gas absorption liquid obtained in the invention is used for treating waste gas, the absorption efficiency of methanol, butanol, benzene, toluene, xylene, ethyl acetate, dichloromethane and acetone is obviously improved, and the absorption efficiency of the waste gas absorption liquid on aromatic hydrocarbon, halogenated hydrocarbon, alcohol, ketone and ester pollutants is improved.

The invention relates to the technical field of lithium / sodium ion batteries, in particular to a preparation method of a highly graphitized coated carbon material based on phenolic resin, which comprises the following steps: uniformly mixing formaldehyde, resorcinol and a basic catalyst, and then catalyzing and curing; carrying out carbonization treatment on the uncarbonized phenolic resin based on a gradient heating method; mixing ethidene diamine, dichloromethane and carbonized phenolic resin, and heating in an oil bath; and placing the cured and coated graphitized phenolic resin in a tubular furnace for highly graphitizing. According to the preparation method of the highly-graphitized coated carbon material based on the phenolic resin, high ordering of a carbon layer is achieved through gradient heating graphitization, a carbon six-membered ring plane is promoted to expand, an ABAB stacked graphite structure is formed, the conductivity is effectively improved, a CVD coating and nitrogen doping synergistic technology is combined, a CVD reaction is formed through ethanediamine and dichloromethane, and the high-graphitization coated carbon material based on the phenolic resin is obtained. Functional groups such as pyridine-N and graphite-N are introduced to the surface of the carbon layer, so that the interface bonding force between the carbon layer and the matrix is enhanced, and the conductivity of the carbon layer is further improved.

The invention discloses an alkenyl epoxidation method, an epoxy resin monomer and application thereof, and belongs to the field of compound synthesis. Aiming at the problems of high halogen content and low preparation universality of the existing epoxy resin monomer, the invention provides an alkenyl epoxidation method which comprises the following steps: dissolving an aromatic compound in an organic solvent, adding an oxidant and a catalyst into the organic solvent, and extracting after complete reaction to obtain the epoxy resin monomer, the preparation method of the catalyst comprises the following steps: dispersing phosphotungstic acid in hydrogen peroxide to obtain an emulsion; adding a trichloromethane solution of cetylpyridinium chloride into the emulsion, and performing liquid separation after the reaction is completed to obtain a catalyst precursor; the catalyst is obtained. The specific catalyst is used, so that the subsequent reaction catalysis efficiency is higher, and the universality is higher; and no epoxy chloropropane is introduced in the whole process of the alkenyl epoxidation method, so that the halogen content of the finally prepared epoxy resin monomer is low, and the limitation barrier that the use of the conventional epoxy resin monomer is limited due to high halogen content is broken through.

The invention provides a preparation method of triphenylchloromethane, and belongs to the technical field of medical intermediates. The preparation method comprises the following steps: preparing a suspension from pure benzene, a composite catalyst and an adsorbent, dropwise adding carbon tetrachloride to obtain a reaction solution, heating the reaction solution to 60-80 DEG C, treating with 808nm laser while stirring, and performing post-treatment to obtain the triphenylchloromethane. The composite catalyst catalyzes pure benzene and carbon tetrachloride to react to generate triphenylchloromethane, hydrogen chloride is released, the adsorbent can adsorb hydrogen chloride in situ, and acid corrosion and catalyst poisoning can be prevented while forward proceeding of the reaction is maintained; the composite catalyst and the adsorbent are used for realizing catalysis-adsorption synergistic promotion of forward proceeding of the reaction, so that the dosage of the catalyst is reduced, the reaction time is shortened, the output of wastewater is reduced, and the reaction yield and the purity of triphenylchloromethane are improved.

The invention belongs to the technical field of hydrophobic electromagnetic shielding materials, and particularly relates to an asymmetric electromagnetic shielding composite film and a preparation method and application thereof. The PNTs are polypyrrole nanotubes, after Na2MoO4. 2H2O and CH4N2S are added and subjected to a high-temperature reaction, a MoS2 flower-shaped shell structure can grow on the PNTs, the layered structure and the high specific surface area of MoS2 contribute to enhancing scattering and absorption of electromagnetic waves, and rich defect sites can induce dielectric polarization to achieve dielectric loss. Introducing the PNTs (at) MoS2 core-shell nanowire as an electromagnetic wave absorbent into a polylactic acid / dichloromethane system, then putting the system into a culture container in which a conductive filler is pre-paved, and standing and volatilizing at room temperature by adopting an ethanol solution as a volatile agent to finally obtain a three-layer asymmetric electromagnetic shielding composite film comprising the conductive filler, the PNTs (at) MoS2 structure and a polylactic acid matrix from bottom to top. And an asymmetric conductive gradient network is constructed, and the EMI shielding performance which mainly focuses on absorption is remarkably improved, so that the secondary radiation problem of electromagnetic waves is reduced.

The invention belongs to the field of chemical production, and particularly relates to a chloromethane cooling recovery system and a chloromethane cooling recovery method. The chloromethane cooling recovery system provided by the invention comprises a first condenser, a second condenser, a third condenser and a recovered chloromethane storage tank, a shell pass inlet of the second condenser is connected with a tube pass outlet of the third condenser, and a tube pass inlet of the third condenser is used for introducing liquid chloromethane. Chloromethane is cooled and recovered by using a liquid chloromethane vaporization heat absorption principle, so that the economical efficiency is good; in addition, due to the fact that the to-be-cooled object and the refrigerant are both methyl chloride, even if mutual leakage occurs in the heat exchange process, the quality of recycled methyl chloride cannot be affected, and raw material losses cannot be caused.

The invention relates to a rapid thin-layer identification method for seven medicinal materials in ten-ingredient nerve-soothing granules. The method is characterized in that two test solutions of a trichloromethane layer and an n-butyl alcohol layer are obtained by a simple, convenient and rapid pretreatment method, the trichloromethane layer can be used for identifying schisandra chinensis, moutan bark and lotus plumule, and the n-butyl alcohol layer can be used for identifying pulp of dogwood fruit, fried gardenia, white paeony root and rhizoma anemarrhenae; the thin-layer identification method disclosed by the invention can be used for identifying 7 medicinal materials in 10 medicinal materials in the whole formula of the ten-ingredient nerve-soothing granules, and is convenient to operate, clear in spots and high in specificity.

The application discloses a continuous system and method for converting low-value glyphosate by-products into high-value chemical products, comprising: pumping low-value glyphosate by-products and alkaline compounds into a constant-temperature conversion kettle for conversion and decomposition, and introducing nitrogen into the top of the constant-temperature conversion kettle to blow off and replace gaseous volatile products generated in the reaction; after gaseous products pass through a buffer tank to capture water vapor, the gaseous products enter a three-stage condenser to recover condensable components into a crude product receiving tank, and the non-condensable components are purified and impurities are removed by an acid absorption system and then utilized; liquid crude product is pumped into a low-temperature vacuum desolventizing kettle to realize separation of condensable components from liquid water, and then enters a two-stage condenser for deep dehydration and separation, and is recovered into a pure product receiving tank. The application realizes a new process for preparing high-purity N,N-diethylmethylamine, and forms a whole-process process system for converting low-value waste materials such as chloromethane, triethylamine and synthetic products thereof into high-value chemical products such as N,N-diethylmethylamine and ethylene.

The invention relates to a post-treatment method and system for chloromethane synthesis, and the post-treatment method comprises the following steps: cooling a chloromethane crude product prepared in a reaction stage through an economizer, and then carrying out gas-liquid separation in a gas-liquid separator, a connecting pipeline between the economizer and the gas-liquid separator is filled with a water flow which flows in a direction opposite to that of the material, so that the temperature of a gas-phase discharge hole in the top of the gas-liquid separator is controlled to be 90-120 DEG C; the separated liquid phase enters a hydrochloric acid buffer tank with a partition plate, and an oil phase and a water phase are separated out; and washing the separated gas phase with water by a water washing tower, and then drying to obtain a chloromethane product. The economizer, the gas-liquid separator with specific temperature control and the hydrochloric acid buffer tank with the partition plate are arranged between the reaction system and the water scrubber, so that three-phase separation of'oil phase silicide-water phase-gas phase 'is efficiently realized, and the oil phase silicide is separated from the chloromethane crude product and does not enter the water scrubber and other subsequent systems; therefore, the problem of pipeline blockage in a post-treatment system is solved.

The present application relates to a kind of preparation method of trifluoromethyl pyrazole compound, belong to the technical field of organic synthesis.The specific method is: (1) trifluoroacetyl ethyl acetate is first with hydrazine hydrate cyclization reaction and generates compound of formula III;(2) under the catalysis of base, compound of formula III is reacted with difluoromethylation reagent and generates compound of formula II;(3) compound of formula II is reacted with methylating agent and obtains compound of formula I;The difluoromethylation reagent is difluoro-monochloromethane or sodium difluoro-monochloroacetate;The methylating agent is chloromethane, bromomethane, iodomethane, dimethyl sulfate or dimethyl carbonate.The present application is prepared by changing reaction route, and the higher-priced raw material methylhydrazine is replaced, and isomer impurity is no longer generated in the product prepared.Not only raw material cost is reduced, but also the purity of product is improved.

The invention discloses a method for simultaneously analyzing polychlorinated biphenyls, polycyclic aromatic hydrocarbons and organochlorine pesticides in water, which comprises the following steps: simultaneously extracting polychlorinated biphenyls, polycyclic aromatic hydrocarbons and organochlorine pesticides in a water sample by using a mixed solvent of n-hexane and dichloromethane, merging while extracting, purifying, concentrating and fixing volume, and testing on a machine in two groups, the polychlorinated biphenyl and the organochlorine pesticide are independently used as a group, the polycyclic aromatic hydrocarbon is used as a group, when an extraction solvent adopts a mixed solvent of dichloromethane and n-hexane, the extraction efficiency is gradually increased along with the increase of the proportion of the n-hexane, and when the volume ratio of the n-hexane to the dichloromethane is 9: 1, the extraction recovery rate can reach 78.9%-111%. When 1% of polyethylene glycol 4000 is added in the mixed extraction process with the volume ratio of n-hexane to dichloromethane being 9: 1, the extraction efficiency is remarkably improved, the extraction efficiency recovery rate reaches 84.6%-112%, and it is indicated that the addition of polyethylene glycol 4000 has the remarkable improvement effect. Compared with the prior art, the extraction efficiency is remarkably improved, and the accuracy and precision of the method completely meet the determination and analysis requirements for measuring complex water samples.

The application relates to a method for synthesizing and refining electronic-grade hexachloroethyldisilane, and specifically, trichlorosilane raw material is mixed with protective gas into a raw material buffer tank, a mixed gas obtained through the mixing is subjected to a catalytic synthesis reaction under the irradiation of an ultraviolet light source, a product obtained through the reaction is subjected to condensation separation, gaseous trichloromethane returns to the raw material buffer tank to continuously participate in the synthesis reaction, the mixed liquid in the cold trap is warmed and vaporized, hexachloroethyldisilane is obtained through two-step refining, and the purity of the product hexachloroethyldisilane can reach the electronic grade. The application takes trichlorosilane as the initial raw material, the price of the raw material is low; the photo-catalysis is used as the synthesis process, the synthesis process is simple, the reaction yield is high, energy is saved, and the environment is protected; the two-step method is used for refining and purifying the product, the depth of the refining and the efficiency of the refining are high, large-scale production is suitable, the monopoly of foreign enterprises is broken, and the application has important significance.

The application discloses a preparation method and application of an alkaline zinc-based flow battery electrolyte, and comprises the following steps: firstly, dissolving a hydroxide solid in deionized water to obtain an alkaline aqueous solution; secondly, dissolving a zinc oxide solid in the alkaline aqueous solution obtained in the step (I) to obtain an alkaline aqueous solution containing a zincate; and finally, dissolving a sugar alcohol and a chloromethane in the alkaline aqueous solution containing the zincate obtained in the step (II) to obtain an alkaline electrolyte. By introducing different concentrations of the sugar alcohol and the chloromethane into the alkaline electrolyte containing the zincate, the double electric layer and the solvation structure of the zinc negative electrode are regulated, the self-corrosion and the hydrogen evolution side reaction problems of the zinc negative electrode under the strong alkaline (pH>14) condition are effectively inhibited, the alkaline electrolyte has good zinc compatibility, high stability and relatively fast reaction kinetics, and has great potential in the development and application of the alkaline zinc-based flow battery.

The present application belongs to the field of chemical production, and particularly relates to a chloromethane cooling and recycling system and a chloromethane cooling and recycling method. The chloromethane cooling and recycling system comprises a first condenser, a second condenser, a third condenser and a chloromethane recycling tank. The shell side inlet of the second condenser is connected with the tube side outlet of the third condenser, and the tube side inlet of the third condenser is used for passing in liquid chloromethane. The present application uses the vaporization endothermic principle of liquid chloromethane to cool and recycle chloromethane, and is good in economy. Moreover, since the to-be-cooled substance and the refrigerant are both chloromethane, even if mutual leakage occurs in the heat exchange process, the quality of the recycled chloromethane will not be affected and the loss of raw materials will not be caused.

The invention discloses a control method for stably recovering reaction heat of liquid-phase catalytic synthesis of chloromethane, which comprises the following steps: two-way shunting control of synthesis gas and reflux control of synthesis gas condensed acid, the first-way shunting control of the two-way shunting control of the synthesis gas comprises the following steps: enabling the synthesis gas to enter a first heat exchanger through a first control pipeline to vaporize methanol; according to the second-path split-flow control, the synthesis gas enters a second heat exchanger through a second control pipeline in a split-range control mode to be cooled; the first path of shunt control of the reflux control of the synthesis gas condensed acid is to form cascade control through the liquid level and the flow so as to return a liquid component into the synthesis reactor through a reflux pipeline, and the second path of shunt reflux control is to enable the liquid component to enter a hydrochloric acid storage tank through a discharge pipeline. The problem that in the prior art, steam needs to be additionally supplemented for methanol vaporization can be thoroughly solved, and long-time stable operation of the synthetic reaction can be guaranteed.

The application belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of methoxychlorpromazine monohydrochloride monohydrate. The method comprises the following steps: step 1, methoxychlorpromazine base is dissolved in a polar solvent, and hydrochloric acid is added to obtain a mixed solution; step 2, a poor solvent of methoxychlorpromazine monohydrochloride monohydrate is added to the mixed solution, crystallization is carried out, and separation is performed, and methoxychlorpromazine monohydrochloride monohydrate is obtained; the poor solvent is selected from one or a mixture of two or more of isopropyl alcohol, n-butyl alcohol, acetone, butanone, ethyl acetate, butyl acetate, dichloromethane, trichloromethane, toluene, methyl tert-butyl ether, isopropyl ether and diethyl ether. The method has the advantages of simple process, good repeatability, easy operation, high yield, product purity of more than 99.8%, complete compliance with the requirements of European Pharmacopoeia 9.0 and US Pharmacopoeia USP43, and suitability for industrial production.

The invention discloses a high-yield method for reducing dinitro and retaining sensitive protecting groups, which comprises the following steps: adding water, sodium dithionite and sodium carbonate into a container, stirring and clarifying, and dropwise adding a mixed solution containing raw materials; after the reaction is finished, extracting, separating liquid, concentrating, and purifying by silica gel column chromatography to obtain a product and a byproduct; the raw material is a compound containing a carbon-carbon double bond, a p-methoxybenzyl protecting group, a t-butyloxycarboryl protecting group and dinitro. Adding a byproduct into a phosphoric acid mixed solution for reaction; and after the reaction is finished, adding dichloromethane and water, dropwise adding triethylamine to adjust the pH value, extracting, separating liquid, drying, concentrating, and purifying by silica gel column chromatography to obtain the product. According to the method, a sodium hydrosulfite / sodium carbonate system and phosphoric acid step-by-step treatment strategy is adopted, reduction of dinitro is achieved under mild conditions, meanwhile, PMB protecting groups, Boc protecting groups and C-C double bonds are reserved, and the problem that stability and high yield of the protecting groups cannot be considered at the same time in an existing method is solved.

The invention belongs to the field of chemical reagent moisture detection, and particularly relates to a coulometry Karl Fischer reagent for aldehyde ketone moisture detection and a preparation method of the coulometry Karl Fischer reagent. The coulometry Karl Fischer reagent for aldehyde ketone moisture detection is prepared from the following components in parts by weight: 1 to 15 percent of imidazole, 1 to 15 percent of 2-methylimidazole, 25 to 70 percent of ethylene glycol monomethyl ether, 5 to 30 percent of trichloromethane, 2 to 30 percent of trifluoroethanol, 2 to 10 percent of sulfur dioxide, 1 to 10 percent of methyl iodide, 0.1 to 5 percent of tetrabutylammonium iodide and 0.1 to 5 percent of iodine. The method does not contain hydroxyl compounds, effectively inhibits the generation of side reactions in detection, ensures the detection accuracy, and improves the product stability and effectively shortens the instrument equilibrium time by adding iodomethane and tetrabutylammonium iodide.

The invention belongs to the technical field of methanol recovery, and particularly relates to a methanol recovery device and method.The methanol recovery device is characterized in that a tower washing water storage tank is used for storing chloromethane tower washing waste water, the tower washing water storage tank is communicated with a distillation still, and the chloromethane tower washing waste water in the tower washing water storage tank is preheated and then sent to the distillation still to be distilled; the distillation kettle is connected with a heater, and the heater circularly heats chloromethane washing tower wastewater in the distillation kettle to be above the boiling point of methanol; aeration pipes are distributed in the distillation kettle, and the magnetic suspension fan is communicated with the aeration pipes after being connected with the lower part of the distillation kettle; the lower part of the condenser is connected with a methanol recovery tank; the magnetic suspension fan volatilizes methanol in the heated chloromethane tower washing wastewater in the distillation kettle through the aeration pipe, and distilled methanol from the distillation kettle is cooled by the condenser and then recovered to the recovered methanol tank. The method improves the methanol recovery yield.

The invention discloses a preparation method of a bilastine intermediate, which comprises the following steps: reacting a compound 5 with thionyl chloride under the conditions that dichloromethane is used as a solvent and DMF (Dimethyl Formamide) is used as a catalyst to generate acyl chloride, and then reacting the acyl chloride with diethylamine to prepare a compound 6; taking dichloromethane as a solvent, and carrying out Friedel-Crafts acylation on the compound 6 and ethyl oxalyl chloride under the condition of anhydrous aluminum trichloride to obtain a compound 7; reducing the compound 7 by using sodium borohydride, liquid caustic soda and a water system to prepare a compound 8; taking dichloromethane as a solvent, and reducing the compound 8 by TMDS under the condition of anhydrous aluminum trichloride to prepare a compound 9; hydrolyzing the compound 9 under the hydrochloric acid condition to obtain a compound 10; and under the condition of thionyl chloride, carrying out esterification reaction on the compound 10 and methanol to prepare the bilastine intermediate TM. The preparation method of the bilastine intermediate, provided by the invention, has the advantages of economical and easily available raw materials, mild reaction conditions, efficient reaction and simple operation, and is suitable for industrial application.

The invention discloses a molecular framework material for direct air carbon capture and a preparation method thereof. According to the material, a series of aldehyde derivatives and diamine derivatives are used as raw materials, trichloromethane and ethanol, dichloromethane and methanol or trichloromethane and water are used as solvents, a stepwise polymerization reaction is performed, after the reaction is finished, trichloromethane and ethanol are sequentially used for washing, and vacuum drying is performed to obtain the molecular framework material. The obtained molecular framework material has a primary amine site, and can chemically react with carbon dioxide in the air so as to realize the target of trapping carbon dioxide in the air. Meanwhile, a long-range hydrophobic region exists in the molecular framework, so that interference of water vapor in the air can be effectively avoided, and specific trapping of carbon dioxide in the air is realized. In addition, interference of water vapor does not exist in the molecular framework in the desorption stage, and the obtained carbon dioxide is high in purity and does not need to be further treated. The invention has the advantages of simple synthesis, low cost, convenient application and simple post-treatment.

The invention provides a synthetic method of 2-(2-amino-5-bromo-benzoyl) pyridine, and belongs to the technical field of medicine synthesis. A one-pot boiling method is adopted, 2-cyanopyridine and 4-bromaniline are used as raw materials, BCl3 is used as a catalyst, dichloromethane is used as a solvent, a heat preservation reaction is performed for 5-25 hours at the temperature of-10 DEG C to 40 DEG C, and the product 2-(2-amino-5-bromo-benzoyl) pyridine is obtained through ethyl acetate extraction, anhydrous sodium sulfate drying and dichloromethane and petroleum ether recrystallization. According to the preparation method of the 2-(2-amino-5-bromo-benzoyl) pyridine, provided by the invention, butyl lithium with extremely high dangerousness does not need to be used, the reaction steps are simple, the yield is stable, the treatment is easy, and the yield is high.

The application discloses a kind of two-dimensional silicon catalysts loaded with copper and its preparation method and application, preparation method includes: under inert atmosphere, the mixture of two-dimensional silicon material and copper salt is annealed at 250~300 DEG C for 4~6h, and solid powder is obtained;Solid powder is washed, and copper salt not bonded with two-dimensional silicon material is removed;Under inert atmosphere, the product obtained by washing is annealed at 500~600 DEG C for 4~6h, and the two-dimensional silicon catalyst loaded with copper described is obtained.The two-dimensional silicon catalyst loaded with copper obtained by the application is mixed with polyethylene plastic, chloroaluminate ionic liquid / trichloromethane solvent and chlorinated tertiary alkane, and the reaction system is irradiated with light, which can drive polyethylene plastic depolymerization to obtain hydrocarbon compounds.The method of the application can realize the complete conversion of polyethylene plastic, obtain high-yield, high-value hydrocarbon compounds, and provide a new idea for green, value-added recycling of plastic waste.

The present invention provides a method for preparing spermidine, which relates to the technical field of organic synthesis. The method for preparing spermidine comprises: condensing 3-chloropropylamine hydrochloride and triphenylmethane to obtain 3-chloro-N-tritylpropylamine; condensing 3-chloro-N-tritylpropylamine and 1,4-butanediamine to obtain N 1 ‑(3‑(tritylamino)propyl)butane‑1,4‑diamine; N 1 The trityl group is removed from 1,4-(3-(tritylamino)propyl)butane to obtain spermidine hydrochloride; and spermidine hydrochloride is liberated in the presence of a base to obtain spermidine. The preparation method of the present invention can achieve a high yield and purity in a relatively short reaction period, avoids the problems of a high proportion of by-products, high purification difficulty, and residual solvent, improves the reaction efficiency, and has mild reaction conditions, simple production equipment, and is more energy-saving and environmentally friendly while being convenient for industrialized amplification production.

The invention provides a system and method for recycling methane chloride from methyl chlorosilane synthesis tail gas. According to the method, 85%-90% of methane chloride in the methyl chlorosilane synthesis tail gas is recycled in a three-stage sectional type condensation mode. 90-95% of residual methane chloride is recovered through directional absorption of dichloromethane; and finally, residual methane chloride is recovered in a decompression analysis and reflux impurity removal mode, the total recovery rate of methane chloride is larger than or equal to 99%, the purity of methane chloride is larger than or equal to 99.5%, waste of methane chloride is greatly reduced, high recovery of methane chloride is achieved, and methane chloride can be directly reused in a methyl chlorosilane synthesis reaction.

The invention discloses a thin-layer identification method of kadsura pepper stem and a preparation thereof, which optimizes a preparation method of a test sample and takes dichloromethane-acetone-methanol as a developing solvent. The method is simple, convenient and rapid to operate, does not need a column chromatography elution separation step, does not damage chemical components of the kadsura pepper stem, maximally presents prototype components of the kadsura pepper stem, and is rich in chromatographic spot information; dichloromethane is used for replacing toxic trichloromethane to serve as a developing solvent, so that the safety and the environmental protection property are enhanced; evaluation is carried out by adopting the consistency of reference medicinal materials, and is more accurate and scientific.