29 results about "Dimethyl benzene" patented technology

The present application relates to a kind of foam type organic chlorine disinfectant and its preparation method and application, belong to disinfectant technical field.Utilize the modification treatment of magnesium sulfate with polysilicic acid, make and form stable package system between modified magnesium sulfate and organic chlorine, greatly improve the stability and long-acting of effective chlorine component in the process of use;While introducing the synergism between surfactant and sodium dimethyl benzene sulfonate, an additional protective layer is constructed, further strengthens the overall stability of organic chlorine disinfectant, blocks the harmful contact that organic chlorine disinfectant can encounter under complex or adverse environmental conditions, effectively prevents the performance decline or potential harm caused by environmental factors, ensures the safe and efficient use of disinfectant.The foam type organic chlorine disinfectant of the present application utilizes double package system, not only improves the long-acting and stability of disinfection effect, but also significantly enhances the environmental adaptability and use safety of product.

The invention discloses a preparation method and application of a heterojunction catalyst based on a two-dimensional zinc porphyrin metal organic framework, and belongs to the field of photochemical energy conversion and photocatalytic degradation. The invention aims to solve the technical problems of high-quality preparation of the artificial photosynthetic photocatalytic composite material and how to effectively improve the photochemical energy conversion efficiency. The method comprises the following steps: 1, dissolving bismuth nitrate pentahydrate, sodium tungstate dihydrate and sodium dodecyl dimethyl benzene sulfonate in deionized water, fully stirring, and transferring the solution to a reaction kettle for hydrothermal reaction; cooling to room temperature, washing and drying to obtain bismuth tungstate solid powder; 2, adding bismuth tungstate and meso-tetra (4-carboxyl phenyl) porphin into a mixed solution of N, N-dimethylformamide and ethanol, carrying out ultrasonic treatment, and fully stirring to obtain a solution A; dissolving zinc nitrate hexahydrate, pyrazine and polyvinylpyrrolidone in a mixed solution of N, N-dimethylformamide and ethanol, and fully stirring to obtain a solution B; after the solution is fully dissolved, dropwise adding the solution B into the solution A under ultrasonic and stirring conditions, and then putting the beaker into an oil bath pan for heating; and cooling to room temperature, washing, and storing in an ethanol solution to obtain the Zn-MOF / Bi2WO6 heterojunction composite material.

The invention relates to application of a traditional Chinese medicine composition in preparation of a medicine for treating hemorrhoids, which is characterized in that the traditional Chinese medicine composition is prepared from angelica sinensis, achyranthes bidentata, cistanche, rhizoma alismatis, cimicifugae foetidae and fructus aurantii. The composition disclosed by the invention can be used for remarkably reducing the anus swelling degree of rats suffering from hemorrhoids, reducing the anus ulcer area of the rats suffering from hemorrhoids and inhibiting xylene-induced inflammatory ear swelling of mice, so that the traditional Chinese medicine composition has a relatively good treatment effect on hemorrhoids.

The invention relates to the field of new material fine chemicals, in particular to a method for efficiently preparing a hexachloroxylene product through chlorination reaction of xylene and chlorine under the participation of a chlorobenzene medium.

A laboratory immunohistochemical staining slide fixing and auxiliary operation apparatus, comprising an immunohistochemical staining slide fixing apparatus (1), a storage box (5), and a dedicated filter box for coverslipping (6). The immunohistochemical staining slide fixing apparatus (1) comprises a slide grasping spring (11), a first handle (12) and a second handle (13), one end of the first and second handles (12, 13) being fixed to two sides of the slide grasping spring (11), respectively, and the other ends each being bent inward to form first and second gripping parts (14, 15). By means of squeezing the handles (12, 13) to drive the top of the slide grasping spring (11) to arch open, multiple staining slides (2) can be inserted and positioned on the slide grasping spring (11); releasing the spring (11) can clamp and fix the slides (2) for subsequent batch immunohistochemical staining operations, such as staining and washing, significantly improving experiment efficiency. The storage box (5) enables centralized storage of multiple slide fixing apparatuses (1), preventing small fixing apparatuses (1) from being lost due to random placement, and reducing laboratory losses. The dedicated filter box for coverslipping (6) is used to place a slide (2) to be coverslipped on a filter mesh thereof for coverslipping processing, allowing residual xylene on the slide (2) to be centrally recovered, and thereby improving laboratory environmental safety and the personal safety of operators.

A self-catalytic imide ring-containing phthalonitrile resin and a preparation method and application thereof, relate to the technical field of aromatic heterocyclic resins, and specifically to a self-catalytic imide ring-containing phthalonitrile resin and a preparation method and application thereof. It is necessary to solve the problems of high melting point, inappropriate curing speed and complicated preparation process of existing self-catalytic phthalonitrile resins. Unsaturated double bonds and imide rings are introduced into the structure of the self-catalytic imide ring-containing phthalonitrile resin, and dimethyl is introduced on the benzene ring at the same time. Method: 4-amino-3,5-xylenol, 4-nitrophthalonitrile and anhydrous potassium carbonate are stirred in a non-protonic solvent, reacted, the product is washed with water, and dried to obtain 4-(4-amino-3,5-dimethylphenoxy)phthalonitrile; then glacial acetic acid is added, heated to reflux, cooled to precipitate the product, washed with water, and dried to obtain the target product. The resin has a moderate curing speed and a relatively low melting point. The resin of the present invention is used for modifying epoxy resins.

In one aspect, a process for the preparation of vilanterol ((R)-4-(2-((6-(2-((2,6-dichlorobenzyl)oxy)ethoxy)hexyl)amino)-1-hydroxyethyl)-2-(hydroxymethyl)phenol; Compound VI) or a pharmaceutically acceptable salt thereof, comprises the following steps wherein steps A to B(i) are carried out as a one-pot or telescoped process: A) coupling the compound (5R)-5-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-1,3-oxazolidin-2-one (Compound II) with 2-[2-(6-bromohexyloxy)-ethoxymethyl]-1,3-dichlorobenzene (Compound III) in the presence of a base, in an organic solvent; and B) (i) adding a base to the reaction mixture formed in step A to remove the oxazolidinone protecting group, to form Compound V; (ii) converting Compound V to vilanterol (compound VI) or a pharmaceutically acceptable salt thereof. In another aspect, a process for the preparation of vilanterol ((R)-4-(2-((6-(2-((2,6-dichlorobenzyl)oxy)ethoxy)hexyl)amino)-1-hydroxyethyl)-2-(hydroxymethyl)phenol; Compound VI) or a pharmaceutically acceptable salt thereof, comprises coupling the compound (5R)-5-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-1,3-oxazolidin-2-one (Compound II) with 2-[2-(6-bromohexyloxy)-ethoxymethyl]-1,3-dichlorobenzene (Compound III) and converting the product formed to vilanterol or a pharmaceutically acceptable salt thereof, wherein during the process either no, or only one, intermediate compound is isolated.

This invention discloses a method for testing the low-temperature crosslinking degree of EVA film, comprising the following steps: Step 1: Selecting a film sample as the first sample; Step 2: Laminating the first sample to form a second sample; Step 3: Cutting the second sample to form multiple third samples; then placing the third samples into a container and adding xylene to the container; Step 4: Placing the third samples into a dimethyl silicone oil bath for low-temperature extraction, with the extraction temperature set at 110±5℃; Step 5: Removing the third samples and drying them; Step 6: Cooling and drying the dried third samples; Step 7: Calculating the degree of crosslinking. This invention's method for testing the low-temperature crosslinking degree of EVA film utilizes a low-temperature heating extraction method to test the crosslinking degree, avoiding secondary crosslinking of the EVA film during continuous heating extraction, ensuring accurate characterization of the actual crosslinking degree of the EVA film, improving the accuracy of test data, and thus reducing the risk of photovoltaic module failure in outdoor environments.

On the basis of a traditional Li medicine for relieving cervical spondylosis, a new Li medicine for relieving cervical spondylosis was developed by adding copper pen flower fruit extract. The copper pen flower fruit extract has bergenin, various phenolic acids and alcohol compounds as the main active ingredients, and has analgesic and anti-inflammatory activities. By improving the traditional Li medicine prescription, a new Li medicine for relieving cervical spondylosis was developed. After the hot plate pain threshold reaction experiment on mice, the acetic acid-induced painful writhing experiment on mice, and the anti-inflammatory experiment on xylene-induced ear swelling in mice, it is fully proved that the copper pen flower fruit extract, the traditional Li medicine for relieving cervical spondylosis, and the new Li medicine compounded with the copper pen flower fruit extract and traditional Li medicine all have the effects of dredging meridians, promoting blood circulation and removing blood stasis, reducing swelling and relieving pain, and dispelling wind and cold, and have anti-inflammatory and analgesic effects. The analgesic and anti-inflammatory effects of the new Li medicine prescription for relieving cervical spondylosis are better than those of the copper pen flower fruit extract and the traditional Li medicine prescription for relieving cervical spondylosis.

The invention relates to the technical field of pesticides, in particular to a herbicidal composition, preparation and application thereof. The herbicidal composition comprises a component A and a component B, wherein, the component A is benzylazole, and the component B is at least one of acetochlor, butachlor, metolachlo, dimethylphenoxychlor, mesotrione, nicosulfuron, atrazine, terbuthylazine, metribuzin, S-metolachlor and dimethylphenoxychlor. The weight ratio of the component A to the component B is 1:(1-80).

The invention relates to the technical field of biology, in particular to a tick-derived histamine binding protein HqHBP and application of a coding gene thereof in resisting anaphylactic reaction. The hemaphysalis qinghaiensis histamine binding protein HqHBP is subjected to recombinant expression to obtain HqHBP recombinant protein, the purified target protein is subjected to in-vitro ELISA (enzyme-linked immunosorbent assay) experiment, the absorbance at 450 nm is measured, and the result shows that the protein can be specifically bound with histamine. The protein can obviously relieve otoedema of a xylene-induced mouse inflammation model, and can directly reduce the content of histamine in xylene-induced skin inflammation tissues. The histamine binding protein is suitable for developing anti-allergic reaction preparations.

The invention relates to the technical field of organic chemical synthesis, in particular to a synthesis method of 2-bromo-5-cyclohexyl-1, 3-dimethyl benzene. The invention relates to a synthesis method of 2-bromo-5-cyclohexyl-1, 3-dimethyl benzene, which comprises the following steps: by taking 2, 6-dimethylaniline as a raw material, halogenating, carrying out nitrosation and carbocation rearrangement to obtain 2-bromo-5-iodine-1, 3-dimethyl benzene with high yield, and coupling with cyclohexyl metal halide to prepare the target product 2-bromo-5-cyclohexyl-1, 3-dimethyl benzene. The 2-bromine-5-cyclohexyl-1, 3-dimethyl benzene has the yield of 78% and the purity of 98.9%, and fills the blank of the synthesis process of the 2-bromine-5-cyclohexyl-1, 3-dimethyl benzene.

The present invention relates to the field of biotechnology, and in particular to an application of a tick-derived histamine binding protein HqHBP and a coding gene thereof in anti-allergic reactions. The Qinghai Haemaphysalis tick histamine binding protein HqHBP of the present invention is recombinantly expressed to obtain a HqHBP recombinant protein, and the purified target protein is subjected to an in vitro ELISA experiment to measure the absorbance at 450 nm, and the result shows that the protein can specifically bind to histamine. The protein can significantly reduce ear edema in a xylene-induced mouse inflammation model, and can directly reduce the content of histamine in xylene-induced skin inflammation tissue. The histamine binding protein is suitable for the development of anti-allergic reaction preparations.

The application discloses a preparation method of N1,N2-dimethyl benzene-1,2-diamine and belongs to the technical field of medical intermediate preparation. The method comprises the following steps: taking o-phenylenediamine as a raw material, reacting with ethyl formate, then adopting dimethyl sulfate to perform a nitrogen-methylation reaction, and finally removing a formyl group under the action of an acid to obtain N1,N2-dimethyl benzene-1,2-diamine. In the method, all raw materials can be conveniently purchased on the market, the process of each reaction is simple, there is no expensive catalyst, the yield is high, and the industrialized production is easy.

The utility model discloses oxygen generator filtering equipment which comprises a fixing plate, an oxygen generator body is fixedly installed on the left side of the top of the fixing plate, an air suction pipe is fixedly connected to the back face of the oxygen generator body, a supporting block is fixedly connected to the right side of the top of the fixing plate, and a filtering box is fixedly connected to the top of the supporting block. According to the air purifier, formaldehyde, benzene, dimethylbenzene and tvoc contained in air and pollutants such as allergens and dust mites contained in the air can be effectively filtered and removed through the multiple stages of filter plates, so that the effect of one-time filtering is achieved, ultrafine particles, bacteria and viruses and the like in the air are conveniently filtered and removed through the HEPA filter plate, and the air purifier has the advantages of being simple in structure and convenient to use. The air quality is guaranteed, an electric push rod is additionally arranged, a sliding plate is conveniently pushed to move, so that the sliding plate drives a moving plate to move, the moving plate drives a cleaning brush to move, and impurity particles adsorbed on the surfaces of the HEPA filter plate and the multi-stage filter plate can be effectively cleaned.

The invention belongs to the technical field of novel biopesticides, and relates to a nano-humic acid and azadirachtin coupled biopesticide and a preparation method thereof.The nano-humic acid and azadirachtin coupled biopesticide is screened out by experimenting and optimizing the concentration and proportion of nano-humic acid and azadirachtin in the nano-humic acid and azadirachtin coupled biopesticide, and the nano-humic acid and azadirachtin coupled biopesticide is used for preparing the nano-humic acid and azadirachtin coupled biopesticide. The water-soluble fertilizer is prepared from the following components in parts by volume: 50 parts of a 2% nano humic acid solution, 1 part of a 1% azadirachtin solution, 40 parts of ddH2O and 9 parts of DMF (Dimethyl Formamide). According to the prepared nano humic acid and azadirachtin coupled biopesticide, particles of the nano humic acid can be minimized and uniform, and the nano humic acid and azadirachtin coupled biopesticide has the dual effects of biopesticide and bio-fertilizer, does not contain organic solvents with high toxicity to human bodies, such as methylbenzene and xylene, and is safer to use.

The invention discloses a unibract fritillary bulb compatible prescription and application thereof, and belongs to the technical field of traditional Chinese medicines. The invention provides a traditional Chinese medicine composition for relieving cough, eliminating phlegm and / or resisting inflammation. The traditional Chinese medicine composition is prepared from 40g of fritillaria unibiacteata, 10-20g of folium eriobotryae, 20-40g of sea-buckthorn and 15-30g of poria cocos. The toxicity of the unibract fritillary bulb compatible prescription is researched by using a mouse acute toxicity experiment, and the prescription is non-toxic according to in-vitro and in-vivo related indexes. Then, a disease model is established through ammonia water cough inducing, tracheal phenol red excretion and xylene ear swelling inducing methods, cough relieving, phlegm eliminating and anti-inflammatory pharmacological experiments are conducted on nine compatibility groups designed through orthogonal experiments, and the optimal compatibility proportion is 40 g of fritillaria unibiacteata, 15 g of folium eriobotryae, 40 g of sea-buckthorn and 22.5 g of poria cocos. The invention provides a new medicine choice for relieving cough, eliminating phlegm or resisting inflammation.

The present invention provides an industrial method for producing 1,4-dimethylnaphthalene with a small content of 1,3-dimethylnaphthalene. In this method for producing 1,4-dimethylnaphthalene, 5-phenyl-2-hexene is cyclized in the presence of acid catalysts to prepare crude 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene, the crude 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene is dehydrogenized to obtain a crude 1,4-dimethylnaphthalene, and the crude 1,4-dimethylnaphthalene is purified by distillation. In this method, the concentration of 1,3-dimethyl-1,2,3,4-tetrahydronaphthalene in 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene is 1.0% or less with respect to the 1,4-dimethyl-1,2,3,4-tetrahydronaphthalene.

The application discloses a toluene disproportionation method for producing dimethylbenzene. The method is characterized in that, under hydrogenation condition, toluene raw material is contacted with a catalyst to generate benzene and dimethylbenzene through toluene disproportionation reaction; the catalyst comprises ZSM-5 molecular sieve with a SiO2 / Al2O3 molar ratio of 10-100 and a binder; wherein, in the ZSM-5 molecular sieve, the amount of external surface acid accounts for 5-40% of the total acid amount, and the external specific surface area accounts for 5-30% of the total specific surface area of the ZSM-5 molecular sieve. The method provided by the application is used for toluene disproportionation reaction, and has the characteristics of high toluene conversion rate, high selectivity of products (benzene+dimethylbenzene), low by-product C9 + A low selectivity.

The invention discloses a method for preparing N-(3-chloro-4-fluorophenyl)-4-fluoro-3, 5-dimethyl benzenesulfonamide by a one-pot method. The method comprises the following steps: adding a catalyst into a reaction kettle; comprising the following steps: reacting 2, 6-dimethyl fluorobenzene with chlorosulfonic acid to generate 4-fluoro-3, 5-dimethyl benzene sulfonyl chloride, then adding 3-chloro-4-fluoroaniline, and carrying out an amidation reaction to generate N-(3-chloro-4-fluorophenyl)-4-fluoro-3, 5-dimethyl benzene sulfonamide. And refining the crude product by using an n-hexane / ethyl acetate mixed solution to obtain a target compound. The N-(3-chloro-4-fluorophenyl)-4-fluoro-3, 5-dimethyl benzene sulfonamide prepared by the process has high purity, and the HPLC (High Performance Liquid Chromatography) purity is gt; the content is 99.0%. The method has the advantages of easily available raw materials, mild operation conditions and low production cost, and is suitable for large-scale industrial production.

The utility model discloses a stabilizing tower for xylene production, which relates to the technical field of xylene production and specifically comprises a thermostatic chamber, a circulating heater, a temperature sensor and a rectifying tower are arranged in an inner cavity of the thermostatic chamber, a first pressure sensor is arranged at the top of an inner cavity of the rectifying tower, and a pressure regulating structure is arranged at the top of the rectifying tower. According to the stabilizing tower for dimethylbenzene production, dimethylbenzene gas rectified in the rectifying tower is pumped out through the first exhaust fan, the working frequency of the first exhaust fan is controlled, the pressure of the top of the rectifying tower is kept balanced, redundant dimethylbenzene gas in the rectifying tower can be stored in the balance chamber in the pressure regulating process, dimethylbenzene loss is avoided, and the production efficiency is improved. The liquid xylene in the balance chamber can be supplemented into the condenser of the rectifying tower, so that the working stability of the condenser is maintained, the pressure fluctuation at the top of the rectifying tower caused by external gas directly entering the rectifying tower is avoided, and the working stability of the rectifying tower is guaranteed.

The invention belongs to the field of coal coking and production and separation of organic chemical products, and particularly relates to a method for producing alkyl etherates from o-cresol post-fraction carbolic oil fraction. The invention provides a method for producing alkyl etherate from o-cresol post-fraction phenol oil fraction, which comprises the following steps: rectifying phenol-containing coal tar to obtain the o-cresol post-fraction phenol oil fraction at 192-195 DEG C, extracting the o-cresol post-fraction phenol oil fraction by using aqueous alkali to obtain upper-layer dephenolized phenol oil and aqueous-layer phenol sodium salt solution, and separating the upper-layer dephenolized phenol oil from the aqueous-layer phenol sodium salt solution to obtain the alkyl etherate. The method comprises the following steps of: heating to remove impurities such as neutral oil in a sodium phenolate aqueous solution, performing etherification reaction with an alkylating agent to obtain water-insoluble o-methyl benzene alkyl ether and 2, 6-dimethyl benzene alkyl ether, and rectifying to obtain high-purity o-methyl benzene alkyl ether and 2, 6-dimethyl benzene alkyl ether. According to the method, the reaction conditions are mild, only etherates are generated in the reaction process, side reactions of alkylation and dealkylation on benzene rings are basically avoided, and the etherification selectivity is good.

The invention provides an application of a tobacco bean extract in preparation of an anti-inflammatory and analgesic external medicine, and in a chronic / acute inflammation model, the tobacco bean extract can effectively relieve mouse atopic dermatitis / ear inflammation symptoms induced by dinitrochlorobenzene (DNCB) / xylene; in the aspect of analgesic effect, the tobacco bean extract can relieve mouse pain response caused by hot plate stimulation and prolong the pain threshold latency period; mechanism research shows that the tobacco bean extract can significantly inhibit expression of various inflammation-related cytokines; therefore, the tobacco bean extract can obviously improve various acute and chronic inflammations, can relieve nerves, and has the potential of treating inflammations and inflammatory pain. Besides, the safety evaluation result shows that no obvious toxic reaction is caused in the experimental dose range, the toxicity burden caused by the inducer can be reduced in a disease model, and the safety and the application prospect are good.

The present invention aims to provide a moisture-curing composition that can yield a cured product with excellent properties, including flame retardancy and adhesive properties. [Solution] A moisture-curing composition comprising a urethane prepolymer U having isocyanate groups at its molecular ends, a latent curing agent L that generates an amine by hydrolysis, and a flame retardant F, wherein the flame retardant F comprises two or more different compounds. The flame retardant F comprises a compound M having a structure in which an amine having a triazine ring and a cyclic ketone are hydrogen-bonded, and a phosphate ester compound C having a viscosity of 1 mPa·s to 500 mPa·s at 25°C. The phosphate ester compound C mainly consists of tris(2-chloro-1-methylethyl) phosphate, trixylenyl phosphate, or trioctyl phosphate. The compound M mainly consists of melamine cyanurate.

The application discloses a trifluoromethyl alkynyl reaction containing photocatalysis 1,6-diene and application. 1,6-diene and alkynyl trifluoromethyl sulfone are used as raw materials, dimethyl benzoyl peroxide and sodium acetate additives are used, methyl tert-butyl ether is used as a reaction solvent, and a five-membered ring compound containing trifluoromethyl and alkynyl is obtained by reaction at room temperature. The synthesis method has the advantages of mild reaction condition, simple and safe operation, cheap and easily available raw material, and is an environment-friendly green synthesis method. Through the method, the trifluoromethyl alkynyl reaction of 1,6-diene can be successfully realized, and the obtained product can be used as an important organic synthon, and a series of molecular structures containing trifluoromethyl can be prepared through further oxidation or reduction reaction.

The present invention discloses an immunohistochemical immunoenzyme labeling method, mainly including paraffin section, xylene dewaxing, gradient alcohol dehydration, blocking, antigen repair, blocking, adding a primary antibody, adding a secondary antibody and adding SP, color development and counterstaining. The method is simple to operate, and the color can be accurately controlled by microscopy to avoid over-staining and ensure the staining effect. The preparation method of each solution is simple, and the dosage is suitable, easy to use, and waste is avoided. Also included is a kit for immunoenzyme labeling method, including endogenous peroxidase blocker, efficient blocking solution, biotin-labeled sheep anti-mouse IgG and streptavidin-peroxidase. The kit includes the solvent required for the above-mentioned immunoenzyme labeling method, and each solvent is packaged in a dropper bottle, which is easy to use.

The utility model relates to the technical field of biological science, and discloses a dewaxing device for paraffin sections, which comprises a processing box and a loading frame, the outer side of the processing box is fixedly connected with a filter box, an activated carbon box is assembled in the filter box, the interior of the processing box is fixedly connected with an air pump located on the front side of the activated carbon box, and the loading frame is fixedly connected with a water pump located on the front side of the activated carbon box. A connecting pipe extending into the processing box is fixedly connected to the outer side of an air outlet of the air pump, a fan located on the rear side of the connecting pipe is fixedly connected to the interior of the processing box, a placing plate is fixedly connected to the inner wall of the loading frame, a placing groove is formed in the placing plate, and a box cover is clamped to the top of the loading frame; and a strip-shaped hole is formed in the loading frame. The dewaxing device for paraffin sections has the advantages that dimethylbenzene volatilized in air is absorbed and treated, multiple sections are dewaxed at the same time, and the dewaxing efficiency is high.

The present invention relates to an enzymatic method for the preparation of 2,6-bis(hydroxymethyl)pyridine starting from 2,6-lutidine using a mutant xylene monooxygenase enzyme (designated ppXMO) comprising the xylM and xylA subunits from Pseudomonas putida, said mutant enzyme having an amino acid exchange at position 116 of the amino acid sequence of the XylM component. The key to the invention is the replacement of methionine (M) at this position with an amino acid selected from the group consisting of asparagine (N), lysine (K), arginine (R) and glycine (G), which surprisingly results in the direct methylhydroxylation of 6-methyl-2-pyridinemethanol, thereby improving the overall process yield, producing fewer by-products, avoiding toxic reaction intermediates and minimizing the involvement of endogenous reductases and the need for NADPH and its regeneration. Other enzymes related to XylM of P. putida that have the same amino acid exchange in the highly conserved region around position 116 or its equivalent show similar improved properties.

The utility model discloses a dimethylbenzene distillation unit device, which relates to the technical field of dimethylbenzene processing and comprises a distillation cup and an auxiliary component, a feeding pipe is mounted on the left side of the top of the distillation cup, and the auxiliary component for assisting the distillation cup to be uniformly heated is arranged outside the distillation cup. The auxiliary assembly comprises an adjusting ring, a folding piece, a bottom support, an auxiliary rod and a limiting block, the folding piece is installed at the lower end of the adjusting ring, the lower end of the folding piece is connected with the bottom support, the auxiliary rod is installed at the upper end of the outer side of the bottom support, the limiting block is installed outside the auxiliary rod through a bolt, and a heating hole is formed in the middle of the bottom support. According to the xylene distillation unit device, the vertical position of the adjusting ring outside the distillation cup is adjusted, so that the height of the folding sheet can be adjusted according to the amount of an original xylene solution in the distillation cup, heat plays a role in covering the outside of the bottom of the distillation cup, the solution is uniformly and fully heated, and distillation extraction of xylene is assisted.