62results about How to "Avoid high temperature reaction" patented technology

The invention discloses a preparation method of a graphene material. The preparation method comprises the following steps of: with graphite carbon as a raw material, adding potassium hypermanganate and concentrated sulfuric acid in batches in different stages to control an oxidation process of graphite; adjusting the pH value of the oxidized solution to obtain graphene oxide colloidal dispersing solutions (GOS) with different concentrations; dropwise adding the GOS on the surface of a carrier or spreading out the GOS on a non-intersolubility liquid / liquid interface and drawing into a grapheneoxide thin-film (GOF); carrying out high-speed centrifugation and drying treatment on the GOS to obtain graphene oxide solid powder (GOP); reducing the GOS by selecting an appropriate reducing agent,and centrifugally drying to obtain reduced graphene solid powder (GRP); dispersing a proper amount of GRP in an organic solvent to prepare a reduced graphene oxide colloidal dispersing solution (GRS); and dropwise adding the GRS on the surface of the carrier or spreading out on the non-intersolubility liquid / liquid interface and drawing into the reduced graphene thin-film (GRF). Various graphene materials prepared by the invention are easy to mutually transform; and the concentration of the colloidal solution and the thickness of the thin-film can be controlled in a certain range.

The invention relates to a synthetic method for an allyl polyether-type high efficiency water reducing agent, belonging to the field of water reducing agent. The synthetic method utilizes allyl polyoxyethylene ether monomer, maleic-anhydride, and a mixture with one or more of (methyl) sodium allylsulfonate, 2-acryl amide-2-methylpropanesulfonic acid, itaconic acid, acrylic acid and acrylamide for obtaining polyether-type high efficiency water reducing agent by initiating one-step polymerization through inorganic peroxides in water solution system, the final structure of the water reducing agent comprises no ester bond, carboxyl, amide, sulfonic group and other functional groups. The synthetic method for an allyl polyether-type high efficiency water reducing agent has the advantages of having applicability for various concrete constructions; having simple and easy process control and non-pollution; resolving the disadvantages of lower polymerization activity of allyl polyether monomer, and resolving the ubiquitous low temperature crystallization problem of allyl polyether-type high performance water reducing agent; and realizing obtaining higher dispersity and preserving degree in low-dosage, particularly, having good dispersion performance on the condition of extremely low water cement ratio.

The invention provides a lithium battery positive electrode material, which comprises a positive electrode active material and a coating layer coating the surface of the positive electrode active material, wherein the coating layer contains Li<1-x>Al<5+y / 3>O<8-x+y> (x is greater than or equal to 0 and less than or equal to 1, and y is greater than or equal to 0 and less than or equal to x), and the mass ratio of the coating layer in the positive electrode material is 0.1%-50%. The positive electrode material provided by the invention does not react with the solid electrolyte LATP at a high temperature, so that the capacity of the positive electrode active material can be normally exerted, and the prepared all-solid-state battery has very good battery performance.

The invention provides a fluorometric analysis based detection method for acrylamide in fried food and relates to detection of the fried food. The method includes: (1) preparing a reagent, to be more specific, preparing 100 microgram / mL acrylamide stock solution, 0.05g / mL polymerizer solution, 3mM photoinitiator, 10% fluorescence sensitizer, 5mg / mL fluorescamine solution and 0.1M phosphate buffered solution; (2) optimizing detection conditions including pH, polymerizer concentration, TPO concentration, fluorescence sensitizer concentration and fluorescamine concentration; (3) polymerizing and detecting acrylamide. Efficiency of converting acrylamide into polyacrylamide is increased; the acrylamide is polymerized into the polyacrylamide at room temperature in daylight, high-temperature reaction is avoided, and safety and stability of the method are improved; by the aid of the fluorescence sensitizer, green fluorescent substances generated by the fluorescamine and the polyacrylamide can be protected, fluorescence intensity can be enhanced, and sensitivity of the method is improved.

The invention discloses a dry degumming method of raw abandoned oil used for producing biodiesel. The method comprises steps that: (1) the abandoned oil is dehydrated; (2) a composite acid with a weight of 0.2 to 1.0% of that of the abandoned oil is added to the abandoned oil, wherein the composite acid is composed of strong phosphoric acid and citric acid according to a ratio of 2:1; the mixture is subject to a reaction for 50 to 90min under a reaction temperature of 100 to 120 DEG C, such that phospholipids form macro flocculating constituents; (3) a degumming absorbent with a mass of 0.5 to 2.0% of that of the raw materials is added to the raw materials; a vacuum degree is controlled at 0.080 to 0.098Mpa, a temperature is controlled at 110 to 130 DEG C, and the mixture is stirred for 30 to 60 min with a rate of 50 to 70r / min; (4) the mixture is processed through press filtration, and an obtained filtrate is a production raw material of biodiesel. The method provided by the invention has advantages of simple technology, high yield, and low production cost. Also, the method is energy saving and environment friendly.

The invention discloses a preparation method for 3-carboxyphenylboronic acid, relating to the technical field of organic synthesis. The preparation method comprises the steps of performing Grignard reaction on m-bromomethyl benzene, magnesium scraps and iodine by using the m-bromomethyl benzene as a starting material, so as to generate a Grignard reagent, performing boronated reaction on the Grignard reagent and trimethyl borate so as to prepare 3-Tolylboronic acid, and oxidizing the 3-Tolylboronic acid with potassium permanganate in an alkaline condition so as to prepare 3-carboxyphenylboronic acid. According to the preparation method, cheap m-bromomethyl benzene easy to obtain is used as the starting material, the 3-carboxyphenylboronic acid is prepared through Grignard reaction, boronated reaction and oxidization reaction, the operations are simple, the average purity of the product 3-carboxyphenylboronic acid reaches 99.3%, and the average total yield reaches 50%. The product yield and purity are ensured at low cost, so that the preparation method is applicable to industrial production.

The invention provides a method for preparing 7-bromine-1-heptylene. The method includes selecting a commercial raw material in markets or tetrahydrofuran prepared easily as a raw material; and carrying out ring opening, hydroxyl group protecting, coupling reaction, deprotection and substation reaction to obtain a target 7-bromine-1-heptylene product. The method has the advantages that the raw material is easy to obtain, reaction purity and yield are high, technological conditions are stable, operation is simple, cost is low, the method is environment-friendly and applicable to large-scale production, and the method is a new idea for preparing the 7-bromine-1-heptylene.

The invention provides a comprehensive utilization method of asparagus. The method includes the following steps that the asparagus is preprocessed; the preprocessed asparagus is crushed and pulped, and slurry is obtained; cellulose and pectinase are added into the slurry, enzymolysis reaction is conducted at 45 DEG C to 55 DEG C under the acidic condition, and a decomposition product is obtained; flavones in the decomposition product is adsorbed, and asparagus flavones and residual liquor are obtained; lactobacillus bulgaricus and streptococcus thermophilus are added to the residual liquor, fermentation is conducted at 35 DEG C to 45 DEG C, and fermentation liquor is obtained; the fermentation liquor is filtered, and trapped fluid and permeate liquid are obtained. According to the comprehensive utilization method of the asparagus, the asparagus is deeply developed, at least two target products of asparagus liquid beverage and asparagus flavones can be obtained, and the method has the advantages of being high in comprehensive benefit, various in product variety, free of damage, free of additive production and the like.

The invention discloses a method for synthesizing an industrial auxiliary N-butylphthalimide. The method comprises the following steps: performing a free radical addition reaction on phthalimide and 1-butene serving as main reacting substrates under an initiator or optical initiation condition to obtain the N-butylphthalimide, wherein the molar ratio of phthalimide to 1-butene in the reacting substrates is 1:1-1:7; the initiator is organic peroxide or inorganic peroxide; the molar ratio of phthalimide to organic peroxide initiator is 5:1-10:1; the molar ratio of phthalimide to inorganic peroxide initiator is 1:1-1:4; the reacting temperature is between normal temperature and 100 DEG C, and the reacting time is 3-24 hours. The method adopts the phthalimide and the 1-butene as raw materials which are low in price and easily available, and has the advantages of mild reacting condition and low production cost.

The invention discloses a method for synthesizing 4-n-butylresorcinol by a microchannel reaction, belonging to the technical field of synthesis of cosmetic intermediates. The method comprises the following steps: dissolving 4-n-butyrylresorcinol in an organic solvent, adding a sodium borohydride reducing agent, and carrying out a reaction at room temperature; then feeding a reaction product into apreheating module, preheating the reaction product to 60-90 DEG C and using the preheated reaction product as a material 1; preheating a Raney nickel / organic solvent turbid liquid in the preheating module to 60-90 DEG C and using the preheated Raney nickel / organic solvent turbid liquid as a material 2; and feeding the two materials to a reaction module for a reaction so as to obtain 4-n-butylresorcinol. The method of the invention has the following advantages: the catalyst used in the method is low in cost; reaction conditions are mild; hydrogen can be slowly released for reduction; operationis relatively simple and safe; and yield is as high as 96%.

The invention relates to a metal hydride, concretely belonging to an aluminum lithium hydride making method, and its character: it adopts soluble aluminum salt and lithium salt as raw materials, and adds precipitator in water solution to coprecipitate Al3+ and Li+ ions; makes drying and high-temperature decomposition processing on the deposit to obtain an oxide; makes hydrogenation reduction on the oxide so as to obtain an aluminum-lithium mixed simple substance, and hydrogenates the mixed simple substance at normal temperature and normal pressure to obtain aluminum lithium hydride. It has low temperature in preparing course, operated at normal pressure, not only reduces energy consumption and eliminates potential danger but also the raw materials are easy to obtain and the technique is simple, and provides a new clean producing technique on friendly terms with environment for preparing aluminum lithium hydride.

The invention discloses a preparation method of cinnamic acid or derivatives thereof. The method comprises the following steps: adding a dichloromethane solution of triethyl phosphonoacetate, sodium chloride and raw material aldehyde into a reaction container, performing room-temperature reaction, adding a saturated water solution of ammonium chloride, stirring, performing organic phase washing, performing reduced pressure treatment to remove a solvent, and performing column chromatography purification to obtain a light yellow oily product; adding a mixed solution of dichloromethane and methanol into a reaction product, stirring, dropwise adding a methanol solution of sodium hydroxide to generate a large quantity of turbid materials, performing reduced pressure distillation on a reaction solution until the reaction solution is dry, removing impurities, extracting, combining organic phases, drying, performing reduced pressure treatment to remove the solvent, and drying in vacuum to obtain a white or light yellow product. According to the method, triethyl phosphonoacetate is adopted as an activating reagent for condensation esterification with aldehyde and then the product is conveniently prepared through alkaline hydrolysis; the reaction can be carried out at room temperature, and the shortcomings of low yield, high reaction temperature, high toxicity and serious pollution in a conventional process are overcome.

A flue gas desulphurization and regeneration method for an ordered graded porous carbon material is disclosed. Phenolic resin and a triblock copolymer are adopted as raw materials to prepare a porous polymer, and then activation is performed by utilizing nitrogen and ammonia to obtain a microporous-mesoporous graded carbon structure. When the carbon material is applied in flue gas desulphurization techniques, the sulfur capacity of activated carbon can be effectively increased, H2SO4 that is a byproduct is more liable to be separated from pore structures, and 80% or above of the H2SO4 can be separated out by adopting a water washing method and is far higher than water washing regeneration efficiencies at present. A high-temperature reaction between H2SO4 and carbon is avoided so that a regeneration process is nearly free of carbon loss.

The invention discloses a preparation method of a high-temperature-resistant ceramic coating on the inner wall of a small-caliber special-shaped metal pipe. The method is mainly used for preparing the coating on the inner wall of a pipe fitting with pipe diameter of less than 15mm, length of less than 500mm and irregular shape. The main preparation process is as follows: 1) preparing paint: the paint contains a silicate adhesive, a high temperature-resistant ceramic material, a solvent and an organic additive; 2) preparing the coating: the preparation of the coating adopts a grouting method, and in order to ensure the uniformity of the developed coating, a grouting device and a coat homogenization device are self-designed; and 3) drying and sealing treatment of the coating: the drying and thermal treatment are performed on the coating under a stipulated system, and then a self-made hole sealing agent is adopted for performing hole sealing treatment on the prepared ceramic high-temperature-resistant coating. The uniform and dense coating capable of working in a high temperature environment of 1200 DEG C is finally obtained.

The invention discloses a diminazene aceturate production method. The method comprises the following steps: reacting p-nitrobenzamide with triethylamine and thionyl chloride to synthesize p-nitrobenzonitrile, and carrying out addition, amination, reduction, diazotization, coupling and salt formation on p-nitrobenzonitrile to obtain diminazene aceturate. P-nitrobenzamide is adopted as a raw material to synthesizes p-nitrobenzonitrile, so high temperature reaction is avoided, and industrial production is facilitated; the addition of urea in the diazotization and coupling reactions is in favor of improving the yield; a reaction product obtained after the coupling reaction undergoes water supply and direct pH adjustment without filtering, heating, dissolving or cooling steps, so the reaction steps are simplified, and the reaction time is shortened; and water and methanol are used as solvents in the salt formation, so the volatilization of methanol is reduced, and the crystal form of diminazene aceturate is obviously improved.

The invention discloses a preparation method of ZnLiMgO nanoparticles and a product prepared from the ZnLiMgO nanoparticles. Lithium salt and alcohol ether are mixed at the room temperature in an alkaline environment, and a first reaction system is obtained; zinc salt is added to the first reaction system, and a ZnLiO dispersion system is obtained after a reaction; magnesium salt is added to the ZnLiO dispersion system, and ZnLiMgO nanoparticles are obtained after a reaction. The ZnLiMgO nanoparticles prepared with the method have surface ligand which is C3-C5 straight-chain alcohol ether. TheZnLiMgO nanoparticles have good film forming property when used as an electron transport layer of a light emitting device, and the service life of the device is prolonged.

The invention relates to a synthetic method for an allyl polyether-type high efficiency water reducing agent, belonging to the field of water reducing agent. The synthetic method utilizes allyl polyoxyethylene ether monomer, maleic-anhydride, and a mixture with one or more of (methyl) sodium allylsulfonate, 2-acryl amide-2-methylpropanesulfonic acid, itaconic acid, acrylic acid and acrylamide forobtaining polyether-type high efficiency water reducing agent by initiating one-step polymerization through inorganic peroxides in water solution system, the final structure of the water reducing agent comprises no ester bond, carboxyl, amide, sulfonic group and other functional groups. The synthetic method for an allyl polyether-type high efficiency water reducing agent has the advantages of having applicability for various concrete constructions; having simple and easy process control and non-pollution; resolving the disadvantages of lower polymerization activity of allyl polyether monomer,and resolving the ubiquitous low temperature crystallization problem of allyl polyether-type high performance water reducing agent; and realizing obtaining higher dispersity and preserving degree in low-dosage, particularly, having good dispersion performance on the condition of extremely low water cement ratio.

The invention discloses a method for preparing white carbon black with the high specific surface area from fluorosilicate. The method comprises steps as follows: firstly, an additive containing an alcoholic hydroxyl group is added to water, fluorosilicate is added to the aqueous solution, ammonia water is dropwise added after even stirring, and the solution reacts continuously; after the reaction, white carbon black with the high specific surface area is obtained through aging, filtration, washing and drying. The operation process is simple, the yield is up to 98% or higher, energy consumption is low, the BET specific surface area of the prepared white carbon black meets the HG / T 3061-2009 class-A standard, and the white activated black can be applied to multiple industries such as rubber, agricultural chemistry, papermaking and the like and has wide application prospect.

The invention discloses a preparation process of octafluoropropane. The preparation process includes a fluorination reaction section, in the fluorination reaction section, hexafluoropropylene and fluorine nitrogen mixed gases enter a tubular reactor in the form of a parallel flow, and a continuous flow gas-phase reaction is carried out under a certain temperature and pressure to generate the octafluoropropane, and at least one static mixer is installed in the tubular reactor. The preparation process has the advantages of simple process, high reaction efficiency, less by-products and high product purity.

The invention relates to hydroxychloroquine sulfate as well as a crystal form and a preparation method of an enantiomer of hydroxychloroquine sulfate. The invention provides a crystal form A hydroxychloroquine sulfate. An X-ray powder diffraction pattern of the crystal form A hydroxychloroquine sulfate has characteristic peaks at 10.8 degrees, 13.0 degrees, 13.3 degrees, 16.9 degrees, 17.2 degrees, 17.5 degrees, 19.9 degrees, 21.3 degrees, 23.5 degrees, 24.0 degrees and 26.7 degrees + / -0.2 degrees, and does not contain hydroxychloroquine nitrogen oxide; the invention provides a hydroxychloroquine crystal, the X-ray powder diffraction pattern has characteristic peaks at 7.5 degrees, 14.9 degrees, 16.5 degrees, 19.2 degrees, 19.6 degrees, 22.8 degrees, 23.6 degrees and 26.7 degrees+ / -0.2 degree; the invention provides an S-hydroxychloroquine sulfate monohydrate, the X-ray powder diffraction pattern has characteristic peaks at 12.2 degrees, 13.0 degrees, 14.9 degrees, 17.8 degrees, 22.7 degrees, 23.3 degrees, 25.0 degrees and 26.2 degrees + / -0.2 degrees; the invention also provides R-hydroxychloroquine sulfate, the X-ray powder diffraction pattern has characteristic peaks at 12.2 degrees, 13.0 degrees, 14.9 degrees, 17.8 degrees, 22.7 degrees, 23.3 degrees, 25.0 degrees and 26.2 degrees + / -0.2 degrees.

The invention discloses a synthetic method for 2,4-difluorobiphenyl, and belongs to the technical field of halogenated biphenyl. The method uses 2,4-difluoroaniline and benzene as raw materials, the 2,4-difluoroaniline is diazotized, and the diazotized product and the benzene are subjected to a coupling reaction to obtain the 2,4-difluorobiphenyl; and the method comprises the following steps: adding trifluoroacetic acid, anhydrous magnesium sulfate, a catalyst and the benzene into a reaction kettle, performing cooling under stirring to temperature of 2-6 DEG C, adding isoamyl nitrite, controlling temperature at 6-10 DEG C, adding the 2,4-difluoroaniline dropwise, controlling reaction temperature at 10-25 DEG C in the adding process, after material addition is completed, performing a reaction under stirring for 1-3 h at temperature of 5-12 DEG C, after the reaction is completed, performing suction filtration on the reaction mixture, performing washing, performing drying, and performingreduced-pressure distillation to obtain the 2,4-difluorobiphenyl. The synthetic method disclosed by the invention is simple, and the synthesized 2,4-difluorobiphenyl has a high yield and high purity.

The invention belongs to the technical field of chemical synthesis and provides a method for preparing a balosavir intermediate. According to the method disclosed by the invention, cheap and easily available 3-hydroxy-2-(hydroxymethyl)-4H-pyran-4-ketone (a compound shown as a formula I) is used as a starting material; TEMPO oxidation, benzyl protection and hydrolysis reaction are carried out; so that the intermediate compound---3-benzyloxy-4-oxo-4H-pyran-2-formic acid shown as a formula Baloxavir is prepared. According to the method, highly toxic chemicals such as methylsulfonyl chloride and selenium dioxide are prevented from being used, and reaction reagents are common materials. In each step of the method, the temperature is controlled below 60 DEG C, high-temperature reaction is avoided, and the safety coefficient is high. The method has the advantages of short synthesis route, short reaction steps, simple operation, common and easily purchased reagents and low price, and suitability for industrial production.

The invention discloses chlorphenesin carbamate and a preparation method thereof. The preparation method comprises the step of mixing a compound shown in a formula (1) with ammonium reagent and alkali in an organic solvent in the presence of water at the temperature of 0-40 DEG C. The preparation method in the invention utilizes a raw material containing ammonium ions so as to avoid using of strong pungent ammonia water, improves production safety and is favor of environment protection.

The invention discloses a polybenzoxazine aerogel heat thermal insulation material and a preparation method thereof. The polybenzoxazine aerogel heat thermal insulation material is characterized in that a bisphenol A benzoxazine monomer is used as a base raw material, polybenzoxazine is obtained by adopting acid-catalysed ring opening polymerization, and the polybenzoxazine comprises three structures corresponding to a structural formula 1. According to the preparation method, a sol-gel method is adopted; acid catalysis ring opening polymerization is carried out at the normal temperature to obtain gel with a three-dimensional network structure; then the gel is subjected to aging, solvent replacement, CO2 supercritical drying and programmed warming and heat preservation processing to obtainthe polybenzoxazine aerogel heat thermal insulation material. The material disclosed by the invention has excellent performance of low moisture absorption, high intensity, flame retardance, low density, low thermal conductivity and the like; the preparation method is simple in process; prices of raw materials are low; low-temperature ring opening polymerization avoids a high-temperature reaction;the polybenzoxazine aerogel heat thermal insulation material and the preparation method thereof have low requirements for the environment, are short in time consumption in the overall process flow and are suitable for industrial production.

The invention belongs to the technical field of silica, and in particular relates to a preparation method of a light calcium carbonate silica composite material. The preparation method of the light calcium carbonate-silica composite material provided by the present invention includes two steps of calcium carbonate reaction and silica reaction. The calcined calcium oxide reacts with water to generate calcium hydroxide, and the calcium hydroxide reacts with sodium carbonate to generate calcium hydroxide. Light calcium carbonate, on this basis, reacts with sodium silicate solution and sulfuric acid solution to generate silicon dioxide, so as to prepare a composite material with calcium carbonate as the core and silicon dioxide as the outer layer. The light calcium carbonate silica composite material provided by the invention adopts silica to coat the calcium carbonate material, improves the acid resistance of the calcium carbonate, reduces the RDA value of the calcium carbonate, and can protect the teeth and remove the enamel when applied in toothpaste. stubborn stains.

The invention discloses a synthesis method of ketamine. The synthesis method comprises the following steps: (i) oxidizing and rearranging 2-chlorophenyl cyclopentyl ketone by using an oxidizing agentto generate 2-(2-chlorophenyl)-2-hydroxycyclohexyl ketone, wherein the reaction temperature is 10-80 DEG C; (ii) condensing 2-(2-chlorphenyl)-2-hydroxy cyclohexyl ketone and a sulfonylation reagent ina solvent to form sulfonate, ie., the ketamine intermediate compound is obtained, wherein the reaction temperature is 30-60 DEG C; and (iii) reacting the ketamine intermediate compound with a methylamine reagent to generate ketamine. The invention also discloses a synthetic method of norketamine. The method comprises the steps (i) and (ii), and further comprises the step (iv) of reacting the ketamine intermediate compound with an amination reagent to generate the norketamine. The method is simple, mild in reaction condition, simple and convenient to operate, low in raw material cost and suitable for industrial mass production, and a high-temperature reaction at 180 DEG C is avoided.

The invention belongs to the technical field of drug synthesis, and particularly relates to a method for synthesizing teriflunomide. The method comprises the following step: by taking 2-cyano-group-N-(4-trifluoromethyl phenyl)-acetamide and acetyl chloride as raw materials, carrying out carbanion nucleophilic substitution reaction in the presence of alkali used as a catalyst to generate the teriflunomide, wherein the alkali is any one or a mixture of more than two of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diisopropyl ethylamine, 1,8-diazabicyclo[5.4.0]C11-7-alkene, sodium hydrogen carbonate, potassium hydrogen carbonate, potassium phosphate, potassium dihydrogen phosphate or sodium sulfite. According to the method, sodium hydroxide is introduced to isothermally participate in reaction with alkali and acetyl chloride, so that the usage of a dangerous chemical is prevented; in addition, the reaction condition is moderate, so that the industrial production is facilitated.

The invention discloses a method for preparing N-substituted-1,2,3,6-tetrahydropyridine, which belongs to the technical field of organic chemistry. Using N-substituted-4-piperidinol as raw material, reacting with triphenylphosphine and azodicarboxylate to convert alcoholic hydroxyl group into alkenyl group to obtain N-substituted-1,2,3,6-tetrahydropyridine. The method is easy to obtain raw materials, easy to operate, and high in product purity, avoids the need for high temperature conditions and the use of highly toxic chemicals in previous methods, and has potential route advantages.

The invention belongs to the technical field of chemical synthesis and provides a method for preparing a baloxavir intermediate. The method of the present invention uses cheap and easy-to-get 3-hydroxyl-2-(hydroxymethyl)-4H-pyran-4-ketone (compound of formula I) as starting material, through TEMPO oxidation, benzyl protection, hydrolysis reaction, The intermediate compound of formula baloxavir——3-benzyloxy-4-oxo-4H-pyran-2-carboxylic acid was obtained. The method of the invention avoids the use of highly toxic chemicals such as methylsulfonyl chloride and selenium dioxide, and the reaction reagents are all common materials. In each step of the method of the invention, the temperature is controlled below 60 DEG C, high temperature reaction is avoided, and the safety factor is high. The method of the invention has short synthesis route, short reaction steps, simple operation, common and easy-to-purchase reagents, low price, and is suitable for industrial production.