636 results about "Methyl benzene" patented technology

The invention relates to the technical field of coatings, in particular to a solvent-free anti-doodling cover agent as well as a preparation method and application thereof. The solvent-free anti-doodling finishing agent is prepared from the following raw materials in percentage by mass: 80 to 95 weight percent of solvent-free methyl phenyl silicone resin, 1 to 5 weight percent of a curing agent, 3 to 8 weight percent of an adhesion enhancer, 0.5 to 3 weight percent of an anti-doodling auxiliary agent and 0 to 6 weight percent of an optional delustering agent. The core is that the adhesion enhancer is an enhanced silane coupling agent and is prepared by carrying out molecular-level chemical bonding on a titanium compound, the silane coupling agent and a self-made antifouling agent. The finishing agent disclosed by the invention has the advantages of high adhesive force, excellent stain resistance, adjustable glossiness and the like, and is suitable for base material protection of various scenes such as building outer walls, household crystal plating and artistic coatings.

The invention provides a method for preparing p-chloromethyl styrene, which comprises the following steps: (1) in the presence of a catalyst and an assistant, carrying out reaction on paraformaldehyde and hydrogen chloride to obtain a chloromethylation reagent; (2) reacting beta-halogenated ethyl benzene with the chloromethylation reagent obtained in the step (1) to obtain chloromethyl halogenated ethyl benzene; (3) adding an extracting agent into the chloromethyl halogenated ethylbenzene reaction liquid obtained in the step (2) for extraction to obtain an oil layer containing chloromethyl halogenated ethylbenzene and a water-containing acid layer, and crystallizing the oil layer to obtain purified p-chloromethyl halogenated ethylbenzene; and (4) in the presence of a solvent, carrying out elimination reaction on the purified p-chloromethyl halogenated ethyl benzene and alkali to obtain p-chloromethyl styrene.

The invention provides a chemical or enzymic method regenerated PET and PTA screening method, which comprises the following steps: pretreating a PET or PTA sample 1, and measuring the content of p-toluic acid, the content of p-carboxybenzaldehyde and the content of m-terephthalic acid by using high performance liquid chromatography; the method comprises the following steps: pretreating a PET or PTA sample 2, pretreating by using a high-temperature pyrolysis method, and measuring an isotope ratio of oxygen-18 to oxygen-16 by using an isotope ratio mass spectrometer; the method comprises the following steps: calculating a cleanliness index, an oxy-18 index and a bottle flake index by using a formula based on a test result, and classifying PET and PTA samples through a decision tree according to the indexes; combining and mixing the PET and PTA products based on the classification result and the requirements of downstream customers on the regeneration method and the regenerated material content; the method is convenient, accurate and reliable, the classification result is objective, the screening efficiency of PET and PTA regenerated by a chemical or enzyme method can be improved, and the economic cost is saved.

The present invention relates to the preparation of cyantraniliprole, comprising the preparation of 8-methyl-2,4-dioxo-1,4-dihydro-2H-benzo[d][1,3]oxazine-6-carbonitrile key intermediate via 2-amino-5-((hydroxyimino)methyl)-3-methylbenzoic acid. Wherein hydroxylamine attacks a benzylic formyl group, to obtain the 2-amino-5-((hydroxyimino)methyl)-3-methylbenzoic acid, that undergoes simultaneously or by consecutive steps dehydrogenation and cyclization to obtain the benzo[d][1,3]oxazine group and the cyano group of the desired product. In addition, an improved method for the synthesis of the benzylic formyl group is also displayed.

The invention relates to the technical field of coatings, discloses a multifunctional fireproof and waterproof polysiloxane coating and a preparation method thereof, and aims at solving the problems that the hydrophobic function of an existing fireproof and waterproof polysiloxane coating is irreversibly lost after a fire disaster, and the fireproof and waterproof synergistic performance is remarkably attenuated in a medium-high-temperature environment. Hydroxyl-terminated methyl phenyl siloxane is used as matrix resin, and is matched with a flame-retardant system composed of melamine modified ammonium polyphosphate, pentaerythritol and amino modified nano-montmorillonite, a hydrophobic repair system composed of polysiloxane capsule wall fluorosilane microcapsules, an interface modifier compounded by an epoxy group and an amino silane coupling agent, and a special auxiliary agent. A three-dimensional covalent network is constructed to anchor all the components, efficient charring and temperature response type hydrophobic repair are achieved, the finished product is prepared through microcapsule preparation, modified flame retardant compounding and coating main body blending, and the finished product has excellent fireproof and waterproof performance, a renewable hydrophobic function after a fire disaster and stable performance at medium and high temperatures and is suitable for industrial long-term protection scenes.

The invention relates to a high-efficiency low-toxicity fireproof heat-insulation composite coating and a preparation method thereof, and the preparation raw materials of the high-efficiency low-toxicity fireproof heat-insulation composite coating comprise the following components in parts by weight: 20-30 parts of modified polysiloxane, 15-25 parts of ammonium polyphosphate, 8-15 parts of melamine, 15-28 parts of an inorganic filler, 10-15 parts of water, 5-10 parts of a cosolvent, and 1-3 parts of a functional auxiliary agent. The modified polysiloxane is an A-B-C type three-section type block copolymer, wherein the A section is a polydimethylsiloxane or methyl phenyl siloxane block; the segment B is an organic silicon chain segment containing a phosphazene structural unit; and the segment C is a polyethylene glycol or polyoxyethylene block. According to the invention, the modified polysiloxane is cooperated with the ammonium polyphosphate salt and the melamine, so that the composite coating has the effects of high-efficiency fire prevention and heat insulation, low toxicity, environment friendliness and excellent film forming performance.

The invention relates to the technical field of catalytic synthesis, in particular to a chloromethylation catalyst, a preparation method of the chloromethylation catalyst and a method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene through the chloromethylation catalyst, and the chloromethylation catalyst is prepared by loading sulfonic acid compounds and (or) pyridine compounds and (or) copper salt on a molecular sieve. The method can improve the localization selectivity of chloromethylation. The method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene comprises the following steps of: reacting beta-bromophenylethane, paraformaldehyde and lewis acid in the presence of the chloromethylation catalyst to generate chloromethyl beta-bromophenylethane, and then performing elimination reaction under an alkaline condition to generate a chloromethyl styrene crude product; the high-purity ortho-position, meta-position and para-position chloromethyl styrene is obtained after the crude product is rectified, the brand-new catalyst is adopted in the method, the reaction selectivity is enhanced, the process is simple, and industrial production is facilitated.

The application provides a preparation method of a liquid crystal elastomer foam doped with boron nitride, comprising the following steps: 1) preparation of a NaCl salt template; 2) preparation of a liquid crystal elastomer monomer solution: a liquid crystal elastomer monomer solution is prepared by adding a sufficient amount of a toluene solution into 1,4-bis-[4-(3-acryloyloxypropoxy)benzoyloxy]-2-methyl benzene RM257 as a liquid crystal unit; 3) formation of a liquid crystal elastomer network; 4) preparation of a pre-crosslinked liquid crystal elastomer foam; 5) deformation programming of the liquid crystal elastomer foam: the pre-crosslinked liquid crystal elastomer foam is placed into the template for constant compression, and secondary crosslinking is performed using ultraviolet light under the constant compression state to form a secondary crosslinking network; at this time, the liquid crystal elastomer foam has a thermoreversible deformation characteristic, which is manifested as expansion at a temperature rise and shrinkage at a temperature drop, and the process cycle is reversible; and 6) preparation of a liquid crystal elastomer / heat-conducting BN composite foam.

This invention discloses an analytical method for benzothiazole contaminants, comprising the following steps: detection by high performance liquid chromatography (HPLC), with the following chromatographic conditions: a phenylhexyl column as the stationary phase, mobile phase A being water, mobile phase B being acetonitrile, and gradient elution; wherein the benzothiazole contaminants are at least one of 2-aminobenzothiazole, 2-hydroxybenzothiazole, benzothiazole, 2-methylbenzothiazole, 2-mercaptobenzothiazole, 2,5-dimethylbenzothiazole, 2-cyanobenzothiazole, ethyl 2-carboxylate benzothiazole, 2-chlorobenzothiazole, 2-bromobenzothiazole, 2-methylthiobenzothiazole, phenylthiocyanate, N-tert-butyl-2-benzothiazole sulfenamide, 2-(2-hydroxyphenyl)-benzothiazole, N-cyclohexyl-2-benzothiazole sulfinamide, dibenzothiazole disulfide, and N,N-dicyclohexyl-2-benzothiazole sulfonamide.

The application discloses a rapid evaporation separation process of m-toluic acid, mainly including five steps of MX removal rapid evaporation, IPA removal rapid evaporation, MTA removal rapid evaporation, IPA refining and MTA refining. The process has the characteristics of short operation period, good separation effect and high MTA yield, and can recover IPA as a by-product, thereby avoiding generation of a large amount of residues.

The utility model discloses a benzyltoluene full-automatic filling device which comprises a base, a supporting rod is arranged on the base, a storage box is arranged on the supporting rod, a feeding bin is arranged on the storage box, a bin cover used for sealing is arranged on the feeding bin, the feeding bin is connected with the bin cover through a lock catch assembly, and an allowance alarm mechanism is arranged in the storage box. The bottom of the storage box communicates with the quantitative box through a flow guide pipe, a sliding plate is slidably connected into the quantitative box, a push rod is fixedly installed on one side of the movable plate, and one end of the push rod extends out of the quantitative box and is slidably connected with the quantitative box. According to the benzyltoluene insulating oil quantitative filling device, due to the arrangement of the quantitative box, the piston plate, the push rod, the controller and the pressure sensor, quantitative filling of benzyltoluene insulating oil can be achieved, and the filling accuracy of the benzyltoluene insulating oil in the benzyltoluene insulating oil quantitative filling device is improved.

The application discloses a preparation method of enciferstat bulk drug and belongs to the field of drug synthesis. 9,10-dimethoxy-2-(2,4,6-trimethylphenylimino)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one (SM) is used as a raw material, and the raw material is reacted with cyclohexylamine under alkaline conditions, and the reaction is washed with water, dried, and concentrated to obtain an intermediate I; the intermediate I is reacted with urea under pressurized heating conditions to prepare an enciferstat drug molecule, the two-step yield is more than 67%, and the purity is more than 99%, the method has a simple operation process, the product is easy to purify, the yield is high, the product purity is high, and a new method for preparing enciferstat bulk drug is provided.

The invention discloses a preparation method of an arfamarana key intermediate, which comprises the following steps: carrying out nucleophilic addition reaction on a compound I and 1-[3-chloro-5-(trifluoromethyl) phenyl]-2, 2, 2-trifluoroethanone under the action of an organic solvent A and alkali to obtain a compound II; dissolving the compound II in an organic solvent B, adding concentrated sulfuric acid, carrying out intramolecular dehydration and cyanogen hydrolysis, and after the reaction is finished, cooling to room temperature for crystal growing to obtain a compound III; dissolving the compound III in an organic solvent C, carrying out intramolecular cyclization and ester hydrolysis reaction on the compound III and hydroxylamine hydrochloride under the action of a certain amount of sodium hydroxide aqueous solution, and after the reaction is finished, collecting a water phase and adjusting the pH value of the water phase, so as to obtain the key intermediate of arfampanaga. The reaction in each step has a high conversion rate, the purity of the prepared arfamarin intermediate is high, and powerful support and guarantee are provided for preparation of high-purity arfamarin.

The application relates to the technical field of finishing agents, and discloses a water-based fluorine-free low-temperature water-repellent finishing agent and a preparation method and application thereof. 2,2-dimethylol propionic acid alkyl ester and methyl phenyl dichlorosilane are reacted to obtain an alkyl ester siloxane copolymer, which is then stirred and dispersed with water and an emulsifier to obtain the water-based fluorine-free low-temperature water-repellent finishing agent. The main chain of the water-based fluorine-free low-temperature water-repellent finishing agent is a hydrophobic phenyl polysiloxane molecular chain, and the side chain contains hydrophobic ester groups and long carbon chains. After finishing of terylene fabric, water molecules can be prevented from contacting the terylene surface, and the hydrophobic and water-repellent performance of the terylene fabric is significantly improved. Moreover, a high water contact angle can be maintained after multiple washes.

The present application relates to a kind of phenol and methanol directly prepared (methyl) anisole mode, the method includes the following steps: under the action of composite catalyst, phenol and methanol are catalytically generated methyl anisole, the composite catalyst is Ho / β molecular sieve catalyst and Ti / UiO-66 with mass ratio Ho / β:Ti / UiO-66 0.3-0.6:1 Mixed composite catalyst.The process reaction step is simple, and synthesis is realized in one step, and the total selectivity of methyl anisole is as high as 76% or more, and can be continuously and stably operated for 3000h.

The present application relates to photosensitive polyimide oligomer, preparation method and polyimide photosensitive resin composition prepared by the same, the present application provides the molecular formula of photosensitive polyimide oligomer, which is prepared from 1, 4, 5, 8-naphthalene tetracarboxylic anhydride, N, N-dimethylacetamide, triethylamine, tetramethyl benzene dimethyl diisocyanate, hydroquinone methyl ether, dibutyl tin dilaurate and hydroxyethyl acrylate according to the molar ratio of 2.5:10-15:1.2-1.6:3.0:0.0035-0.0045:0.007-0.01:2-2.5.The good solubility group is introduced into the molecular structure, so that it has good solubility in active diluent, and the polyimide oligomer can be photocured reaction;The device printed by the polyimide photosensitive resin composition prepared by the same has small shrinkage, high precision, and has the excellent performance of photosensitive polyimide oligomer, and has certain toughness and excellent weather resistance.

The application relates to the technical field of high polymer materials, in particular to ammonia-removing and humidity-controlling water gel as well as a preparation method and application thereof, which comprises the following raw materials: deionized water, AM, MBA, Gly, lithium chloride, 2-hydroxy-2-methyl propiophenone, magnesium chloride or magnesium oxide; the AM and the MBA are added into the deionized water, and polymerization is initiated by 2-hydroxy-2-methyl propiophenone and ultraviolet light to form a polyacrylamide network, so that the novel water gel can stably control humidity and effectively remove ammonia in long-term storage, effectively adsorb ammonia and provide molecular-level water molecules, and the required humidity of a cigar is maintained; secondly, the MBA is added into the water gel to form a more stable and porous three-dimensional crosslinking network, which can not only adjust the moisture absorption / relaxation rate of the water gel, realize humidity buffering, but also adsorb ammonia molecules through acid-base neutralization, ion exchange, hydrogen bonding, electrostatic interaction, so that the water gel can maintain the required humidity of the cigar for a long time and reduce the volatilization of ammonia.

The application discloses a synthesis method of afugan, which comprises the following steps: 1-[3-chloro-5-(trifluoromethyl)phenyl]-2,2,2-trifluoroacetone and 4-acetylnaphthalene carboxylic acid are added into a solvent, a base is added, DMAP is added after complete reaction at 50-80 DEG C, acetic anhydride is added dropwise, tetrabutylammonium bromide is added after complete reaction, and an aqueous solution of sodium hydroxide and hydroxylamine hydrochloride is added, and reaction is carried out at 0-5 DEG C, so that an intermediate is obtained; the intermediate is reacted with acyl chloride under the action of DMF and dichloromethane, so that 4-(5-(3-chloro-5-(trifluoromethyl)phenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazole-3-yl)-1-naphthalene carboxylic chloride is prepared; 2-amino-N-(2,2,2-trifluoroethyl)acetamide hydrochloride and a dichloromethane solution of a base are added dropwise, and reaction is carried out at 0-5 DEG C, so that afugan is obtained. The method has a short route, high yield and suitability for large-scale industrial production.

The invention belongs to the field of medicinal chemistry, and relates to an indole allylamine amide derivative as well as a preparation method and application thereof. Functional activity screening of G protein dependent signaling pathways is carried out on all the synthesized compounds, and it is found that the new derivatives can be used for preparing beta2-adrenergic receptor allosteric antagonism regulator drugs. Trans-indole allylamine is used as a raw material, amide coupling is performed to obtain the novel indole allylamine amide derivative, and R1 is any one of phenyl, m-methylbenzene, m-methoxyphenyl, m-bromophenyl, m-chlorphenyl, m-fluorophenyl, o-methoxyphenyl, p-methoxyphenyl, naphthalene ring, oxazole, cyclohexyl, cyclopentyl, methyl, ethyl and isopropyl. A biological activity test result shows that the indole allylamine amide derivative disclosed by the invention has relatively good antagonistic activity on beta2AR and can be used for carrying out negative allosteric regulation on the functional activity of isoproterenol.

This invention relates to the field of organosilicon compound synthesis technology, specifically to a method for preparing pentaphenyltrimethyltrisiloxane and its application. The preparation method includes: S1, mixing diphenylmethylchlorosilane and methylphenyldichlorosilane for co-hydrolysis to obtain an intermediate raw material; S2, adding a catalyst to the intermediate raw material under vacuum to carry out a catalytic polymerization reaction to obtain a polymer product; S3, vacuum distilling and extracting the target component from the polymer product obtained in step S2 to obtain pentaphenyltrimethyltrisiloxane. The preparation method of this invention, by adjusting the raw material ratio, selecting a suitable catalyst, controlling its dosage, limiting the polymerization process parameters, and precisely controlling the distillation separation conditions, achieves a product purity of over 99% and a refractive index stable between 1.5765 and 1.5790, while also improving industrial production efficiency and meeting the product quality requirements of high-end fields.

The application relates to the technical field of organic synthesis, and discloses a synthesis method of benzthiazuron, which comprises the following steps: step 1, addition reaction of alpha-methyl styrene and hydrogen chloride gas, and degassing to obtain a first reaction liquid; step 2, substitution reaction of the first reaction liquid and cyanate in the presence of a zinc chloride catalyst, and filtration to obtain a second reaction liquid containing isocyanate; and step 3, construction of an inorganic salt aqueous solution system with a density of 1.05-1.10 g / ml and a pH of 9-10, dropwise addition of the second reaction liquid into the system for condensation reaction with o-chlorobenzylamine, and post-treatment and refinement to obtain a target product. The non-phosgene route of chloro-isocyanate substitution is adopted, and the use of the toxic phosgene is completely avoided; the salting-out effect and interface control generated by the specific high-density salt solution effectively inhibit the isocyanate hydrolysis side reaction, and the reaction yield and product purity are obviously improved.

The invention discloses an intermediate for preparing optically pure berbamine and spirosine and a preparation method of the intermediate. The intermediate is a compound (S)-1-(4-(5-(((R)-8-bromo-6, 7-dimethoxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinoline-1-yl) methyl)-2-hydroxyphenoxy) benzyl)-6-methoxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinoline-7-alcohol (20a) or a compound (S)-1-(3-(4-(((R)-8-bromo-6, 7-dimethoxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinoline-1, 2, 3, 4-tetrahydroisoquinoline-1, 2, 3, 4-tetrahydroisoquinoline-1, 2, 3, 4-tetrahydroisoquinoline-1, 2, 3, 4-tetrahydroisoquinoline-1, 2, 3, 4-tetrahydroisoquinoline-1, 2, 3, 4-tetrahydroisoquinoline-1 The preparation method comprises the following steps: firstly, carrying out a multi-step reaction on 5-bromovanillin, 4-hydroxyphenylacetic acid and 4-benzyloxy-3-methoxybenzaldehyde which are used as initial raw materials to obtain optical pure berbamine and spirosine, and then, carrying out a multi-step reaction on the optical pure berbamine and spirosine to obtain the optical pure berbamine and spirosine, and carrying out a reaction on the optical pure berbamine and spirosine to obtain the optical pure berbamine and spirosine. The synthesis route adopts a convergent synthesis mode, the synthesis efficiency is high, the reaction condition is mild, the safety is high, and the operation is simple and convenient.

Disclosed herein are amine containing copolymer compositions based on free radical and controlled radical polymerization of monomer compositions including an amine-derivatized alpha-methyl styrene (ADAMS) monomer according to structure (I): with k, R, R1, and R2 defined herein with one or more monomers selected from the group consisting of optionally substituted acrylates, methacrylates, acrylamides, methacrylamides, acrylonitriles, methacrylonitriles, vinyl ethers, N-vinyl amides, or combinations thereof. Further disclosed herein are methods of making and methods for using such copolymer compositions.

The invention discloses a process method for co-production of caprolactone and 2, 4-dimethyl benzoic acid. According to the method, cyclohexanone is taken as a raw material, oxygen is introduced as an oxidant, 2, 4-dimethyl benzaldehyde is added as a pro-oxidant, and caprolactone and 2, 4-dimethyl benzoic acid are generated through oxidation reaction. According to the technological method, oxygen and 2, 4-dimethyl benzaldehyde are used as a co-oxidation system, in the presence of the carbon framework material loaded Ti-based catalyst, cyclohexanone can be subjected to oxidation reaction under mild conditions to generate caprolactone, the reaction is safe and efficient, the selectivity of the product caprolactone and the co-product 2, 4-dimethyl benzoic acid is high, the raw material conversion rate is high, and the method is suitable for industrial production. The product yield can be obviously improved, and the economic applicability is good.

The application provides a method for preparing isobutylbenzene from benzene and butene, which comprises four reactions in sequence; the first reaction is to synthesize sec-butylbenzene from benzene and butene; the second reaction is to generate 2-phenyl-2-butene by dehydrogenation of sec-butylbenzene; the third reaction is to generate 2-methyl-1-phenylpropene by isomerization of 2-phenyl-2-butene; and the fourth reaction is to generate isobutylbenzene by hydrogenation of 2-methyl-1-phenylpropene; the butene comprises 1-butene and / or 2-butene. The method uses benzene and butene as raw materials, adopts a four-step continuous series fixed-bed reaction process to synthesize isobutylbenzene, is simple to operate, can realize continuous production, does not need to use the metal potassium-sodium catalyst used in the traditional isobutylbenzene synthesis process, has small safety risk, and is suitable for industrialized production of isobutylbenzene.

The invention discloses a preparation method of a covalent organic framework photocatalyst for photocatalytic reduction of CO2, which comprises the following steps: adding 4, 4 ', 4' '-(1, 3, 5-triazine-2, 4, 6-triyl) triphenylamine and 2, 5-dibromobenzene-1, 2, 4, 5-tetracarboxylic dianhydride into a reaction kettle, then adding 1-hydroxy-3-methylbenzene and isoquinoline, and uniformly mixing; and carrying out microwave heating on the reaction kettle, cooling to room temperature, filtering, collecting precipitate, washing, and then carrying out Soxhlet extraction and vacuum drying to obtain the covalent organic framework photocatalyst. A surface halogen atom modification strategy is designed and used for regulating and controlling electron distribution and light capture capacity of a donor-acceptor (D-A) in TzPm-COF, and results show that the strategy can effectively improve photocatalytic activity and selectivity of reduction of CO2 into CO, and can be applied to preparation of the TzPm-COF catalyst. A reasonable design strategy is provided for developing a functional modified COFs material for efficiently and selectively photocatalytic CO2 reduction.

The present application relates to the technical field of fine chemicals synthesis, and discloses a method for high-selectivity co-production of phthaloyl chloride and benzoyl chloride. The method uses dimethylbenzene and trichlorobenzene as raw materials, and feeds them into a photochlorination reaction tower to heat the materials. Then, the reaction tower is kept in a micro-negative pressure condition to perform photochlorination reaction. After the reaction is completed, the liquid is directly fed into a reaction kettle, and phthalic acid and a catalyst are added. Finally, the reaction liquid is separated by rectification to obtain the products phthaloyl chloride and benzoyl chloride. The present application greatly improves the selectivity of dimethylbenzene photochlorination reaction, and inhibits the ring chlorination side reaction. The present application can realize flexible co-production of m-phthaloyl chloride and p-phthaloyl chloride and benzoyl chloride, and can flexibly adjust the generation ratio of phthaloyl chloride and benzoyl chloride according to the raw material supply and product demand, thereby greatly improving the production flexibility of the reaction device.

This application relates to a method for preparing melitracen hydrochloride intermediates, belonging to the field of chemical preparation. The preparation method includes the following steps: dissolving 3,3-dimethyl-2-benzofuran-1(3H)-one in an organic solvent, adding a catalyst and heating the reaction, followed by purification after the reaction to obtain 10,10-dimethylanthrone. The catalyst includes at least one selected from ferric chloride, ferrous chloride, zinc chloride, and anhydrous aluminum trichloride; the organic solvent includes benzene. This preparation method has not been reported in the literature, significantly shortens the process flow for synthesizing melitracen intermediates, avoids the use of concentrated sulfuric acid, reduces waste, and saves costs.

The invention relates to the technical field of organic synthesis, and discloses a preparation method of trimethylbenzoquinone, which comprises the following steps: mixing a reaction solution containing unsym-trimethylbenzene and an organic solvent with a catalyst, and adding an oxidizing agent to carry out oxidation reaction to obtain trimethylbenzoquinone, wherein the catalyst comprises a pyridine compound and methylrhenium trioxide. According to the method, the unsym-trimethylbenzene is adopted as a raw material, the methylrhenium trioxide and the pyridine compound are adopted as catalysts, the trimethylbenzoquinone is prepared through oxidation of the oxidizing agent, the product yield is high, and the consumption of the oxidizing agent is low.