42 results about "Trimethylbenzenes" patented technology

The invention relates to the technical field of C9 heavy aromatics, in particular to a method and device for producing mesitylene from C9 heavy aromatics, and the method comprises the following steps: firstly, in the presence of a catalyst, mixing the C9 heavy aromatics with hydrogen, performing dealkylation isomerization reaction and dehydrogenation separation to obtain a liquid-phase product, and then performing two-stage separation on the liquid-phase product to obtain mesitylene. And mesitylene is produced to the maximum extent. The C9 heavy aromatics are subjected to selective dealkylation and trimethylbenzene isomerization reaction, and the obtained product does not contain propylbenzene, and the content of methyl-ethylbenzene is 1t; the method has the advantages that the yield of mesitylene is more than or equal to 0.2%, the interference of methyl ethyl benzene on the separation of the mesitylene is eliminated, the loss of the mesitylene is small, the one-way yield of the mesitylene is more than or equal to 12%, the reaction process is simple, the mesitylene and unsym-trimethylbenzene products are high in purity, the unsym-trimethylbenzene can be recycled to further increase the yield of the mesitylene, the process is flexible, byproducts are few, the product value is high, and the utilization value of C9 heavy aromatic hydrocarbon resources is obviously improved.

The present application belongs to the technical field of aromatic hydrocarbon production, and relates to a method and system for producing trimethylbenzene and quarterphenyl by alkylation. Light aromatic hydrocarbons and methanol are used as raw materials, and alkylation is carried out under the catalysis of a modified molecular sieve catalyst and at a temperature of 250-600 DEG C. The material after alkylation is subjected to further alkylation under the catalysis of the modified molecular sieve catalyst and at a temperature of 250-600 DEG C. The modified molecular sieve catalyst is composed of a molecular sieve and a metal oxide supported in the molecular sieve, the molecular sieve is one or more of HY, Hbeta, IM-5, NU87, EU-1 and mordenite, and the metal in the metal oxide is one or more of Mg, Cu, La, Zn and Mo. The present application solves the technical problems of low content of trimethylbenzene and quarterphenyl components and difficult separation of trimethylbenzene and quarterphenyl in the industrial separation method by directly producing trimethylbenzene and quarterphenyl.

The invention belongs to the technical field of preparation of herbicides, and particularly relates to a preparation method of tralkoxydim. The preparation method comprises the following steps: carrying out ethylation reaction on 3-hydroxy-5-(2, 4, 6-trimethylphenyl)-2-propoximido-cyclohex-2-ene-1-ketone and halogenated ethane under an alkaline condition, so as to prepare tralkoxydim. According to the method, the use of ethoxyamine hydrochloride or ethoxyamine in the traditional process is innovatively avoided, the raw material cost is reduced, the ethylation reaction is carried out by using halogenated ethane, the reaction raw materials are cheap and easy to obtain, meanwhile, single sodium / potassium halide wastewater is produced, the wastewater treatment process is greatly simplified, meanwhile, the generation of carnallite wastewater and carnallite-containing solid waste is eliminated, and the method is suitable for industrial production. The method has the advantages of environmental protection, economy and simple process, and is suitable for industrial large-scale production.

The invention discloses a method for preparing nitro-mesitylene through a micro-channel nitration reaction. The method comprises the following steps: respectively conveying mesitylene, fuming nitric acid and sulfuric acid to a micro-channel reaction module through a metering pump, and completing nitration reaction within a retention time of tens of seconds to several minutes. The introduction sequence of nitration reaction materials, the reaction retention time and the reaction temperature are cooperatively controlled, the nitration reaction is completed in the microchannel reactor in a continuous flow mode, operation is easy and convenient, safety is high, efficient continuous production can be achieved, meanwhile, emission of three wastes is reduced, and the industrial application advantages of being environmentally friendly and economical are achieved.

The application discloses a kind of by polydopamine mesoporous nanoparticles crosslinked sulfhydrylated hyaluronic acid hydrogel and its preparation method and application, with dopamine and 4-formylphenylboronic acid as monomer, with trimethylbenzene as and poloxamer as template agent, in weak alkaline (pH=8.4), oxygen exists in the environment, by the oxidation self-polymerization reaction between monomer Preparation of polydopamine nanoparticles with mesoporous structure.Then the water dispersion of polydopamine nanoparticles is mixed with sulfhydrylated hyaluronic acid solution according to certain proportion, and the hydrogel dressing with injectable property is prepared.The hydrogel is expected to be used as skin wound dressing for the treatment of diabetic wounds.

The application mixes NaX type molecular sieve with kaolin mineral as a binder, then rolls into a ball, calcines at high temperature, converts kaolin into metakaolin, then treats with alkali, converts into X type molecular sieve in situ, then ion exchanges to prepare high selective adsorbent. The prepared adsorbent has high trimethylbenzene adsorption selectivity, compression strength and bulk density.

The invention is applicable to the technical field of biomass energy catalysis and conversion, and provides a high-activity and high-stability nickel-cobalt alloy catalyst and a synthesis method and application thereof, and the synthesis method comprises the following steps: preparing S-1 zeolite; the preparation method comprises the following steps: mixing S-1 zeolite with an aqueous solution of Ni (NO3) 2.6 H2O and an aqueous solution of Co (NO3) 2.6 H2O for dipping, placing the mixture in a tetrapropylammonium hydroxide solution for hydro-thermal treatment, and performing static calcination to obtain a NixCoyO at S-1 nanocrystal; mixing the NixCoyO (at) S-1 nanocrystal with polymers P123, F127, dopamine hydrochloride and 1, 3, 5-trimethylbenzene, performing ultrasonic dispersion in a mixed solvent of water and ethanol, adding ammonia water for reaction, and collecting NixCoyO (at) S-1 (at) mPDA; and carrying out carbonization and reduction on the NixCoyO (at) S-1 (at) mPDA to obtain the NixCoy (at) S-1 (at) mC catalyst. The prepared catalyst has excellent hydrodeoxygenation performance, vanillin can be efficiently converted into 2-methoxy-4-methylphenol (MMP) under mild conditions, and the yield exceeds 94%.

The application relates to an asymmetric catalytic synthesis method and application of chiral azido tertiary alcohol and azulenic compound. The method is characterized in that under an air atmosphere, a racemic azido tertiary alcohol compound ((+ / -) I) and tri (4-methylphenyl) phosphorus (II) are reacted in toluene by taking chiral tartaric acid derivative phosphoric acid C1, a spirochiral phosphoric acid C2 or octahydroazulene phosphoric acid C3 as a chiral catalyst, the reaction is carried out at 30 DEG C for 17-72 hours, and target chiral azido tertiary alcohol compound (I) and chiral azulenic compound (III) are obtained through separation and purification. S I) and chiral azulenic compound (III) can be used for synthesizing chiral ligand IV, and deuterium water can be added in the reaction system to be used for synthesizing chiral deuterated azulenic compound (D-III).

The application relates to the technical field of catalyst materials, in particular to a preparation method and application of a catalyst for synthesizing dimethyl carbonate from carbon dioxide and methanol; the method comprises the following steps: A, poloxamer is configured into a solution, HAc, NaClO4 and 1,3,5-trimethylbenzene are added into the solution and uniformly mixed to obtain a mixture; B, (NH4)2Ce(NO3)6 and H2BDC are added into the mixed solution in step A, the obtained solid after reaction is centrifugally separated, washed, soaked and dried to obtain a primary product, and finally the catalyst is obtained through calcination; in the application, HF-UiO-66 is synthesized by taking F127 as a template agent and taking 1,3,5-trimethylbenzene (TMB) as an expanding agent; the derivative HF-CeO2 catalyst with different TMB adding amounts is prepared through calcination; the adding of the expanding agent greatly increases the specific surface area of the catalyst, the CeO2 crystal grains generated through calcination are small, the number of acid-base sites is greatly increased, and therefore the catalyst has the largest catalytic activity, and the DMC yield reaches 12.02 mmol DMC / g cat .

The invention discloses an aromatic hydrocarbon alkylation catalyst as well as a preparation method and application thereof. The catalyst comprises: 10 to 90 parts of a ZSM-5 molecular sieve; 0.05-10 parts of at least one selected from Co, Mo and La in terms of metal oxide; and 20-60 parts of a binder component. In an XRD diagram of the ZSM-5 molecular sieve, characteristic diffraction peaks of crystal faces (101), (200), (501) and (303) are broadened, and the aspect ratios of the broadened diffraction peaks are independently selected from 2-7. When the catalyst is used in a reaction for preparing C8 aromatic hydrocarbon, unsym-trimethylbenzene can be co-produced, and meanwhile, the content of m-xylene in xylene and the content of ethylbenzene in the C8 aromatic hydrocarbon are reduced, so that the quality of the product C8 aromatic hydrocarbon is improved.

The invention relates to a device and a process method for producing trimellitic anhydride by continuous liquid-phase oxidation of unsym-trimethylbenzene. The device comprises an oxidation reaction tower, a DTB crystallizer, a horizontal screw centrifuge, an anhydride forming tower and a rectifying tower which are connected in sequence, the oxidation reaction tower is provided with N feed ports and N gas inlets, wherein N is greater than or equal to 3; 2N distributors are arranged in the cavity of the oxidation reaction tower; and the distributor is respectively connected with the feeding hole and the air inlet. The whole technological process is simple, the equipment investment is low, the automation degree is high, the product yield is high, the quality is good, the overall energy utilization efficiency is high, and part of problems existing in an intermittent process are solved.

The invention belongs to the field of paint, and particularly relates to PU electrostatic spraying high-wear-resistance white matt finish paint and a preparation method thereof.The PU electrostatic spraying high-wear-resistance white matt finish paint is prepared from a component A, a component B and a component C. The component A is prepared from odorless matting resin, a wetting agent, a defoaming agent, matting powder, superfine ceramic powder, an organic silicon flatting agent, an anti-settling agent, conductive titanium dioxide slurry and xylene; the component B comprises a bright tripolymer, a matte tripolymer, an HDI (hexamethylene diisocyanate) tripolymer and butyl acetate; the component C comprises trimethylbenzene, cyclohexanone, a DBE high-boiling-point solvent, butyl acetate and an alcoholic solution of an amine salt compound; the conductive titanium dioxide slurry comprises odor-free matting resin, conductive titanium dioxide, a wetting agent and xylene. By means of the superfine ceramic powder, excellent hardness, wear resistance and certain whiteness can be provided for the coating, and the chemical stability of the coating is improved. The conductive titanium dioxide slurry can achieve the electrostatic surrounding effect, and multiple surfaces of a workpiece can be evenly oiled at the same time during electrostatic spraying.

The invention discloses a method for preparing durene by utilizing unsym-trimethylbenzene and methanol, which comprises the following steps: mixing unsym-trimethylbenzene, methanol and hydrogen, heating and gasifying, feeding into a fixed bed reactor, and carrying out alkylation reaction through a molecular sieve catalyst with hierarchical pore distribution to prepare durene, after a reaction product flowing out of the alkylation reactor is subjected to gas-liquid separation and oil-water separation, liquid-phase hydrocarbon components enter a rectification separation system, and light hydrocarbon with the carbon number of C6 or below, methylbenzene, xylene, trimethylbenzene, tetramethylbenzene and aromatic hydrocarbon fractions with the carbon number of C11 or above are separated out. The mesoporous channel of the catalyst increases the contact probability of the raw material and the active site of the molecular sieve, promotes the playing of the activity of the catalyst in a fixed bed, reduces the diffusion resistance of the raw material and the product, promotes the rapid diffusion of the product, and reduces the occurrence of side reactions, so that the conversion rate of unsym-trimethylbenzene and the selectivity of durene are improved; therefore, high durene yield can be obtained.

The invention relates to the technical field of catalyst materials, in particular to a preparation method and application of a catalyst for synthesizing dimethyl carbonate from carbon dioxide and methanol. Comprising the following steps: A, preparing poloxamer into a solution, adding HAc, NaClO4 and 1, 3, 5-trimethylbenzene into the solution, and uniformly mixing to obtain a mixture; b, (NH4) 2Ce (NO3) 6 and H2BDC are added into the mixed solution in the step A, a solid obtained after reaction is subjected to centrifugal separation, washing, soaking and drying, a head product is obtained, and finally, the catalyst is obtained through calcination; according to the invention, F127 is used as a template agent, 1, 3, 5-trimethylbenzene (TMB) is used as an expanding agent to synthesize HF-UiO-66, and the HF-UiO-66 is calcined to prepare a derivative HF-CeO2 catalyst with different TMB addition amounts. The specific surface area of the catalyst is greatly increased due to the addition of the expanding agent, CeO2 crystal grains generated by calcination are reduced, and the number of acid-base sites is also increased in a large area, so that the catalyst has the maximum catalytic activity, and the DMC yield reaches 12.02 mmol DMC / gcat.

The application discloses a kind of catalysts for hydrogen storage material and its preparation method and application, belong to hydrogen storage material and its preparation technical field.The present application is to solve the problems such as high dehydrogenation temperature of existing magnesium-based solid hydrogen storage material and slow low-temperature kinetics.The present application is prepared by using nickel chloride hexahydrate, acetylacetone manganese, polyether P123, polyether P127, dopamine hydrochloride, 1,3,5-trimethylbenzene and ammonia as raw materials to obtain carbon as carrier wrapped with elemental Ni nanoparticle catalyst with a large number of edge dislocations, and is applied to Mg-based hydrogen storage material by ball milling method.The introduced dislocation has a dual role: not only directly accelerates the dissociation of H2 molecule, but also indirectly improves the activity of catalytic phase (Mg2NiH4 / Mg2Ni).The preparation process of the composite hydrogen storage material provided by the present application is simple and mature, and the raw materials are cheap and easy to obtain, only a small amount of MNC needs to be added to greatly improve the hydrogen storage performance of Mg, and it is convenient for large-scale industrial production.

The invention discloses a crude oil pour point depressant which comprises a main agent, an auxiliary agent and a high-flash-point organic solvent, and the mass ratio of the main agent to the auxiliary agent to the high-flash-point organic solvent is (25-35): (1-3): (62-74); wherein the main agent is formed by polymerizing ethylene-vinyl acetate, polyacrylic acid octadecanamide and alkyl maleimide according to a molar ratio of (2.8 to 3.2): (1.8 to 2.2): (1.8 to 2.2); the auxiliary agent is one or any combination of oleic acid diethanolamide, N-oleoyl sarcosine and hydroxy fatty acid; the high-flash-point organic solvent is one or any combination of trimethylbenzene, tetramethylbenzene, propylene glycol butyl ether and diethylene glycol monobutyl ether. The invention also discloses a preparation method and application thereof. The crude oil pour point depressant provided by the invention can effectively reduce the condensation point of high-condensation-point crude oil of which the condensation point is greater than 40 DEG C and improve the fluidity of the high-condensation-point crude oil of which the condensation point is greater than 40 DEG C, so that normal transportation of the crude oil is ensured, and powerful support is provided for reducing the operation cost of the high-condensation-point crude oil and ensuring normal transportation of the crude oil.

The present invention relates to an aromatic organic solvent composition and a paint composition including the same. In some embodiments, the present invention relates to an aromatic organic solvent composition in which a weight ratio of C9 aromatic hydrocarbon to C10 aromatic hydrocarbon is 1:1.5 to 1:2.8, a weight ratio of trimethylbenzene and tetramethylbenzene is 1:0.1 to 1:1, the content of naphthalene is 5 ppm or less, and a pour point is −90° C. to −30° C.

The invention discloses cold zinc spraying resin based on acrylic amino silicon oil and a preparation method and application thereof. The preparation method comprises the following steps: taking acrylic amino silicon oil, methyl methacrylate, styrene, ethyl acrylate and 90-92% benzoyl peroxide, uniformly stirring, and pouring into a head tank; the method comprises the following steps: adding 70-75% of trimethylbenzene into a reaction kettle, heating to 80 DEG C while stirring, introducing nitrogen into the reaction kettle with trimethylbenzene, and preserving heat at 80 DEG C; dropwise adding the mixed monomer in the elevated tank into the reaction kettle uniformly within 3 hours, and preserving heat at 80 DEG C for 1 hour; adding the rest 8-10% of benzoyl peroxide and the rest 25-30% of trimethylbenzene into the reaction kettle, and keeping the temperature for 2 hours; and heating the reaction kettle to 85 DEG C and preserving heat for 1 hour to obtain the acrylic amino silicon oil modified cold spraying zinc resin. And mixing the mixture with dimethylbenzene, an anti-settling agent and zinc powder to prepare the cold zinc spraying coating. The coating disclosed by the invention has better rain resistance and no floating property.

The application discloses a sub-micron Py-TPA COF monocrystal wafer and a preparation method thereof, and belongs to the material field. The preparation method of the Py-TPA COF monocrystal wafer comprises the following steps: mixing tetra-(4-aminophenyl)pyrene, p-phthalaldehyde, mesitylene and an acetic acid solution, and performing a solvothermal reaction to obtain the Py-TPA COF monocrystal wafer. The preparation method has the advantages of short reaction time and high reaction yield, and the prepared sub-micron Py-TPA COF monocrystal wafer has uniform morphology and size.

The present disclosure relates to a method for catalytic conversion of heavy aromatic hydrocarbons, which can efficiently convert heavy aromatic hydrocarbons into light aromatic hydrocarbons through a non-hydrogen cracking reaction, thereby avoiding the shortcomings caused by the production of light aromatic hydrocarbons by hydrogen treatment, solving the problem of difficult utilization of low-value heavy aromatic hydrocarbons, and realizing efficient utilization of resources. Moreover, part of other C9+ products obtained by catalytic cracking of the raw material in the second reaction zone is returned to the first reaction zone of the cracking reaction unit for recycling, which can make full use of heavy aromatic hydrocarbons in the raw material, improve the yield of light aromatic hydrocarbons, and improve the utilization rate of the raw material. In addition, the technical solution of the present disclosure can improve the yield of light aromatic hydrocarbons while co-producing trimethylbenzene and mesitylene, improve the separation efficiency of trimethylbenzene and mesitylene, and reduce the energy consumption required for separation. When the raw material contains non-aromatic hydrocarbons, low-carbon olefins can also be produced.

The invention belongs to the field of air pollution control engineering, and particularly relates to a mesoporous alumina-based carbonyl sulfide hydrolysis catalyst as well as a preparation method and application thereof. The method comprises the following steps: dissolving P123 and trimethylbenzene in ethanol at room temperature; adding aluminum isopropoxide, concentrated hydrochloric acid and citric acid, fully stirring and dissolving, and aging; calcining a substance obtained by aging in a muffle furnace, washing and drying to obtain a mesoporous alumina substrate; (2) dissolving a rare earth metal salt A in distilled water at room temperature to prepare a solution; dipping the mesoporous alumina substrate obtained in the step (1) in the solution obtained in the step (2), and then filtering, washing and drying; and then dipping in alkali liquor, and drying to obtain the mesoporous alumina-based carbonyl sulfide hydrolysis catalyst. The hydrolysis catalyst prepared by the method has the characteristics that a small amount of carbonyl sulfide impurities in high-concentration carbon dioxide can be removed, and the acid resistance is good; the carbonyl sulfide removal rate can reach 90% or above; the catalyst can be used at low temperature, and the operation temperature is low.

This invention discloses a C9+ heavy aromatic hydrocarbon lightening catalyst, its preparation method, and its application. The catalyst uses modified ZSM-5 molecular sieve and modified Beta molecular sieve as acid cracking components, and Group VIB and / or Group VIII metals as hydrogenation components. The ratio of acid content inside the micropores to acid content outside the micropores of the catalyst (A...) in / A out The ratio of micropore volume to mesopore volume (V) should be no less than 100, preferably 200-500. micro / V meso The concentration is 1.0~5.0, preferably 1.5~3.5. The method includes the modification process of the ZSM-5 molecular sieve and the Beta molecular sieve, and the kneading and molding process. The catalyst has both long-chain alkylbenzene dealkylation activity and toluene / trimethylbenzene alkyl transfer activity, realizing the lightening of heavy aromatics without the need for external toluene, and effectively avoiding side reactions such as trimethylbenzene disproportionation and aromatic condensation, delaying carbon deposition, and improving the operating cycle of the device.

Disclosed herein are catalyst compositions having improved mercury intrusion volume and surface areas and processes for making these compositions. The enhanced compositions disclosed herein contain zirconium, cerium, optionally yttrium, and optionally one or more rare earths other than cerium and yttrium. Further disclosed are processes of producing these compositions involving supercritical drying after addition of mesitylene. The compositions can be used as a catalyst and / or as part of a catalyst system in an automobile exhaust system.

The application discloses a mixed acid nitration organic wastewater treatment method and system and belongs to the technical field of organic chemical wastewater treatment. ‑ The application can effectively degrade toxic and harmful pollutants in wastewater and meets the subsequent biochemical treatment demand, and provides practical value for effective treatment of wastewater in the production process of nitryl pyrazole compounds.

This invention relates to the field of mesitylene production technology, specifically a method for producing mesitylene from C9 aromatics. The method involves reacting C9 aromatics with hydrogen via a hydrodealkylation reaction. The dealkylation products are then separated; the gaseous product is returned to a reverse dealkylation reactor, while the liquid product is separated. The bottom product from the BTX tower is then fed into a mesitylene tower for further separation. The bottom product from the mesitylene tower is then fed into a mixing tower for further separation. The top product from the mixing tower undergoes an isomerization reaction, and the isomerization products are then separated to obtain mesitylene. This invention features a simple process flow, using C9 aromatics as raw material. The combined production process of dealkylation and tricresyl isomerization minimizes side reactions, reduces hydrogen consumption, and allows for further utilization of byproducts. The resulting product contains less than 0.5% methyl ethyl phenyl (MEP), eliminating MEP interference with tricresyl separation, improving the yield and purity of mesitylene, reducing production costs, and enhancing the utilization value of C9 aromatics resources.

The present application relates to the technical field of water-based architectural coatings, in particular to a water-based flame-retardant coating, a preparation method and application thereof, which is composed of the following raw materials in parts by weight: 40-50 parts of water-based polyurethane resin, 20-30 parts of deionized water, 2-4 parts of trimethylbenzene, 8-10 parts of dipropylene glycol methyl ether, 8-12 parts of functional additive, 5-8 parts of stabilizer, 4-6 parts of regulator, 1.2-1.8 parts of active agent, 0.3-0.6 parts of diluent and 0.2-0.3 parts of leveling agent; the functional additive is prepared by modifying cardanol and added, which effectively utilizes the thermal stability and flame-retardant property of cardanol, changes the thermal decomposition mode of the coating after the coating is applied, dried and formed, reduces the production of combustible substances in the high-temperature state of the coating, and the functional additive can generate a carbon layer in the combustion process when the coating encounters flame, which has the effect of flame-retardant and oxygen isolation, further improving the flame-retardant property of the coating.

The application belongs to the technical field of carbon materials, and discloses a preparation method of carbon molecular sieve with super-high specific surface area, an electrode, a battery and a supercapacitor. Molecular sieves with different structures are used as templates, which are placed in saturated carbon source steam for sufficient absorption, and trimethylbenzene is used to clean the surface of the unabsorbed carbon source and to wash, then the obtained mixture is placed in a tube furnace, heated and reacted under a nitrogen atmosphere to obtain an intermediate; the molecular sieve template in the intermediate is removed, washed and dried to obtain the final product. The application firstly proposes to fill the template with carbon source steam; the prepared carbon molecular sieve has super-high specific surface and high structural regularity; the carbon molecular sieve used as a sodium battery electrode material can achieve excellent overall performance.

This invention relates to the field of producing mesitylene from reformed C9 heavy aromatics, specifically a method, apparatus, catalyst, and preparation method for producing mesitylene. The method for producing mesitylene includes removing C9 heavy aromatics from C9 heavy aromatics via a de-heavy tower. 10 The above-mentioned heavy components convert the separated C9 mixed aromatics into dealkylation isomerization products. These products undergo gas-liquid separation to obtain liquid hydrocarbon products, which are then separated in a distillation column. Light components are produced at the top of the distillation column, mesitylene is produced from the side stream, and the bottom product is returned to the heavy hydrocarbon removal column, achieving material recycling. This invention uses reformed C9 heavy aromatics as raw material, developing a highly efficient catalyst and reaction separation process to solve the interference of methyl ethyl benzene in existing processes, retain mesitylene, reduce by-product generation, increase mesitylene yield, improve catalyst stability, extend operating cycle, reduce mesitylene production costs, and enhance the utilization value of C9 mixed aromatics.

The application relates to the technical field of medicine synthesis, and discloses a synthesis method of N-Boc-vinylglycine methyl ester and isomerate, which comprises the following steps: L-N-tert-butoxycarbonylmethionine methyl ester is prepared by taking L-methionine methyl ester hydrochloride as raw material; L-N-tert-butoxycarbonyl-4-methylsulfinylbutyric acid methyl ester is synthesized by taking L-N-tert-butoxycarbonylmethionine methyl ester and sodium periodate as raw material; and compound 13 is obtained by reacting L-N-tert-butoxycarbonyl-4-methylsulfinylbutyric acid methyl ester and 1,2,4-trimethylbenzene at 180-190 DEG C for 6-8 h; the Boc protection methionine is directly eliminated in the application, and unnecessary complicated steps are reduced; N-Boc-vinylglycine methyl ester is synthesized in high yield and high selectivity by taking N-Boc-methionine methyl ester sulfoxide as raw material, removing low-boiling-point by-products methylsulfinic acid by evaporation and accurately controlling the reaction temperature; and the structural formula of the compound 13 is as follows:

The invention discloses a production method of p-xylene, which comprises the following steps: (I) C8 < + > aromatic hydrocarbon enters a hydrodealkylation unit, and a dealkylation liquid phase product enters a BTX fractionation unit; (II) feeding methylbenzene and trimethylbenzene / tetramethylbenzene separated by the BTX fractionation unit into a liquid-phase transalkylation unit, and feeding a liquid-phase transalkylation product into the BTX fractionation unit; (III) the C8 aromatic hydrocarbon separated by the BTX fractionation unit enters a PX separation unit, and a p-xylene product and PX-poor C8 aromatic hydrocarbon are obtained through separation; and (IV) the PX-poor C8 aromatic hydrocarbon enters a liquid phase isomerization unit, and a liquid phase isomerization product enters a BTX fractionation unit. The method provided by the invention adopts a process combining a C8 < + > aromatic hydrocarbon gas-phase high-selectivity hydrodealkylation technology, a liquid-phase transalkylation reaction and a liquid-phase isomerization reaction, and has the characteristics of low loss and energy consumption and less investment.