35 results about "Methiodide" patented technology

The invention discloses a synthesis method of 7-dehydrocholesterol and derivatives thereof, which comprises the following steps: cooling a compound (I), cuprous bromide and dimethyl sulfide compound under the protection of inert gas to obtain a reaction system, adding a Grignard reagent (II) or a Grignard reagent (III), stirring, reacting at room temperature, carrying out heating reaction, and cooling to obtain the 7-dehydrocholesterol. Performing post-treatment to obtain a product; if the product is the Grignard reagent (II), the product is 7-dehydrocholesterol and the derivative thereof; if the reagent is the Grignard reagent (III), the product is 25-hydroxy-7-dehydrocholesterol and the derivative thereof. The method is high in total yield, mild in reaction condition, simple in process route, high in product purity, low in three-waste generation amount, simple in post-treatment, environment-friendly and low in equipment requirement, the purity of 95% or above can be obtained through simple recrystallization, and conventional chemical equipment can be used for production.

The invention discloses a plasma catalyst, a preparation method thereof and application of the plasma catalyst in degradation of dimethyl sulfide by plasmas. The plasma catalyst comprises a manganese oxide carrier and Ag monoatoms loaded on the manganese oxide carrier; the manganese oxide carrier comprises rod-like crystalline manganese dioxide and amorphous manganese oxide wrapping the outer layer of the crystalline manganese dioxide. The preparation method comprises the following steps: 1) uniformly dispersing rod-like crystalline manganese dioxide in a mixed solution B of potassium permanganate and manganese sulfate, stirring for reaction, then carrying out solid-liquid separation, taking a solid, washing and drying to obtain a manganese oxide carrier; and 2) dispersing the manganese oxide carrier in deionized water, then adding a silver nitrate solution into the deionized water, uniformly mixing, then dropwise adding a hydrogen peroxide solution, stirring for reaction, then carrying out solid-liquid separation, taking a solid, washing, drying and calcining in a non-oxidizing atmosphere to obtain the plasma catalyst.

The invention discloses a Pd-coated S-COF catalyst for a reaction of preparing styrene through phenylacetylene hydrogenation as well as preparation and application of the Pd-coated S-COF catalyst. The Pd (at) S-COF catalyst comprises a covalent organic framework carrier S-COF and Pd nanoparticles, the covalent organic framework carrier S-COF is an imine bonded covalent organic framework prepared by using 2, 4, 6-tri (4-aminophenyl)-1, 3, 5-triazine and 2, 5-dimethyl thioether-1, 4-phthalaldehyde as raw materials, and the Pd nanoparticles are used for modifying Pd nanoparticles. The Pd nano-particles are encapsulated in pore channels of the S-COF and are loaded on the surface of the S-COF. The invention provides an application of the Pd-coated S-COF catalyst in a reaction for preparing styrene through phenylacetylene hydrogenation, and high phenylacetylene conversion rate and high styrene selectivity can be realized within a short reaction time.

The invention relates to the technical field of organic sulfide preparation, in particular to a method for synthesizing and refining dimethyl sulfide (DMS) and dimethyl sulfoxide (DMSO) embedded into a methanol plant, which mainly utilizes high-purity oxygen of an air separation unit of the methanol plant, a high-concentration hydrogen sulfide product of low-temperature methanol washing and part of top gas-phase refined methanol of a pressurizing tower of a methanol rectification device. The production cost of the product is reduced, the added value of the product is improved, and the hydrogen sulfide product of a methanol plant is effectively utilized.

The invention belongs to the technical field of preparation of adsorption separation functional materials, and discloses a controllable preparation method and application of an S-COFs nanosheet adsorbent. According to the method, 2, 5-dimethyl sulfide terephthalaldehyde DMTTPA and 1, 3, 5-tris (4-aminophenyl) benzene TAPB are taken as monomers, cyanobenzene is taken as a reaction solvent, benzoic acid is taken as a catalyst, aniline is taken as a competitor, and the high-crystallinity S-COF adsorbent is controllably prepared under the condition of high temperature by accurately regulating and controlling crystallization time and combining a dialysis purification technology. The method not only realizes controllable morphology, but also greatly improves the adsorption performance. The method has important economic value in the field of precious metal recovery, the problems of precious metal resource waste and environmental pollution in electronic waste can be effectively solved, and meanwhile, a new thought is provided for designing a low-cost high-performance adsorbent.

The invention belongs to the technical field of atmospheric pollutant control, and relates to a polyacid functionalized guanidine salt ionic liquid system for removing hydrogen sulfide and dimethyl sulfide. The harm of hydrogen sulfide and dimethyl sulfide to a human body and the environment is elaborated, and the limitations of secondary pollution, high energy consumption and the like of the existing removal method are indicated. According to the system, 1, 1, 3, 3-tetramethylguanidine salt and amino acid ionic liquid are dissolved in water according to the ratio of 1: 1 to prepare tetramethylguanidine amino acid ionic liquid, and then Keggin type polyacid is dissolved in the tetramethylguanidine amino acid ionic liquid. The method comprises the following steps: respectively carrying out removal experiments on hydrogen sulfide with the concentration of 500-1000mg / m < 3 > and sulfur-containing VOC (Volatile Organic Compounds) with the concentration of 120-13000mg / ml by using the system at the temperature of 25-45 DEG C by taking N2 as carrier gas, and monitoring tail gas by using a specific instrument. Embodiments show that the system has a good removal effect on both hydrogen sulfide and sulfur-containing VOC, and has application potential in related fields.

The invention discloses a synthesis method of a high-abundance C-13 ethylene oxide compound, which comprises the following steps: (1) carrying out reaction on 13CH3I and diphenyl sulfide to obtain [13C] diphenylmethyl iodide; and (2) reacting the [13C] diphenylmethyl iodide with a carbonyl compound to obtain the high-abundance [13C] ethylene oxide compound. Diphenyl sulfide is adopted to replace dimethyl sulfide, the obtained [13C] methyl diphenyl sulfonium iodide avoids C-13 loss in the subsequent reaction process, and the abundance of C-13 is effectively improved.

The invention discloses a preparation method of an eprinomectin intermediate oxide. The eprinomectin intermediate oxide is obtained by taking an abamectin hydroxyl protection substance as a starting raw material through oxidation reaction and post-treatment. According to the invention, active manganese dioxide is adopted as an oxidizing reagent, the operation is simple, the generation of peculiar smell of a by-product dimethyl sulfide during dimethyl sulfoxide oxidation in the prior art is avoided, the yield reaches 98.0% or more, the purity of the oxide can reach 95.0% or more, and the content of double-oxide impurities can be controlled to be 0.2% or less.

The invention belongs to the technical field of material synthesis, and particularly relates to calcium dodecahydrododecaborate as well as a synthesis method and application thereof. According to the synthesis method of calcium dodecahydrododecaborate provided by the invention, calcium hydride CaH2, a borane dimethyl sulfide complex and an ether mixed organic solvent react in a reaction kettle to obtain a product, and monoethylene glycol dimethyl ether and tetrahydrofuran cyclic ether are compounded to obtain the ether mixed organic solvent; according to the method, the yield and purity of the product calcium dodecahydrododecaborate are improved, meanwhile, deionized water is used for carrying out solvent exchange on the product and drying is carried out, the purity of the product calcium dodecahydrododecaborate is further improved, efficient synthesis of calcium dodecahydrododecaborate is achieved, industrial preparation is facilitated, high-purity calcium dodecahydrododecaborate is provided, and the method is suitable for industrial production. The method is expected to meet the requirement of solid electrolyte battery commercialization on electrolyte, and solves the technical problem of lack of an efficient synthesis process of calcium dodecahydrododecaborate at present.

The present invention discloses a class of sulfur-containing polyethylene glycol derivatives, a preparation method thereof, and an application thereof in the selective oxidation of alcoholic hydroxyl groups. The derivatives are bis-methylthio polyethylene glycol and bis-methylsulfinyl polyethylene glycol, which are polyethylene glycol-supported methylthio and methylsulfinyl groups. The bis-methylthio polyethylene glycol can replace dimethyl sulfide as an activator in the Corey-Kim oxidation, and an important intermediate compound 2'-benzyloxycarbonyl-4"-oxoazithromycin A for the synthesis of tulathromycin is obtained with a yield of 78.8%; and 2'-benzyloxycarbonyl-4"-oxoazithromycin A is obtained with a yield of 90.3%. 5-O-(tert-butyldiphenylsilyl)-23-oxonimoctine, an important intermediate compound in the synthesis of moxidectin, is prepared using bis(methylsulfinyl)polyethylene glycol (PEG) as an oxidant in the Swern oxidation, replacing dimethyl sulfoxide. The sulfur-containing PEG derivatives of the present invention are low-cost to prepare and can be used in Corey-Kim and Swern oxidations, avoiding the use or production of foul-smelling dimethyl sulfide and providing a green environment for these reactions.

The application discloses a MOFs derived N-rich doped three-dimensional porous Co / NC-D composite material and a preparation method thereof. The method comprises the following steps: adding an organic ligand into methanol and ultrasonically dissolving to obtain an organic ligand solution; adding Co(NO3)2.6H2O, Zn(NO3)2.6H2O and dicyandiamide (DCDA) into methanol and ultrasonically dissolving to obtain a metal salt solution; adding the organic ligand solution into the metal salt solution, stirring, centrifuging, washing and drying to obtain a ZIF-67-D or ZnCo-ZIF-D material; and performing calcination, acid washing, filtering, drying and vacuum drying to obtain the material. Compared with Co / AC, Co / rGO and a material obtained by directly calcining ZIF-67, the material has good dispersity and small Co nanoparticles and a synergistic effect between Co and N species, exhibits excellent performance in catalyzing dimethyl sulfide oxidation under mild conditions and has recyclability and a good application prospect.

The invention discloses a Karl Fischer moisture determination method for sulfur-containing organic compounds, and belongs to the technical field of chemical analysis. The method comprises the following steps: adding absolute methanol, imidazole and an inhibitor (selected from N-substituted maleimide or acrylate compounds) into a titration system, then adding a sample, and titrating with a pyridine-containing Karl-Fischer reagent to the end point. The inhibitor can effectively capture reducing sulfur species and eliminate interference of the reducing sulfur species on iodine. Experiments show that for sulfur-containing samples such as 2, 2-dimethylthiopropane, dimethyl sulfide, dimethyl disulfide and the like, the deviation reduction rate of the method is more than 60% compared with that of a traditional method; the method is easy and convenient to operate, high in accuracy and suitable for moisture analysis of sulfur-containing organic matter in the fields of petrifaction, pharmacy and the like.

The invention discloses a room-temperature rapid preparation method of light metal hydroboron, and relates to the technical field of hydrogen storage materials. The method specifically comprises the following steps that S1, metal hydride is subjected to ball milling pretreatment according to a certain ball-to-material ratio; s2, mixing the pretreated metal hydride and dimethyl sulfide borane in a flask, then adding a solvent, and carrying out ultrasonic-assisted reaction; and S3, transferring the solid product into a tubular furnace, and carrying out vacuum drying to obtain the metal borohydride. The method has the advantages of simple process, low price, one-step reaction and high safety; the yield is obviously improved, the reaction conditions are obviously reduced, the production efficiency is greatly improved, and the method has an industrialization prospect.

The invention discloses a water-resistant polycrystalline manganese oxide catalyst as well as a preparation method and application thereof in catalyzing ozone oxidation to remove dimethyl sulfide. The preparation method comprises the following steps: 1) adopting any one of methods 1-3, wherein the method 1 comprises the following steps: adding potassium hydroxide and divalent manganese salt into an aqueous dispersion of delta-MnO2, and stirring for a period of time at the temperature of 40-60 DEG C; the method II comprises the following steps: adding inorganic acid into the aqueous dispersion of delta-MnO2, and stirring for a period of time at 40-60 DEG C; a third method comprises the following steps: firstly adding potassium hydroxide and divalent manganese salt into the aqueous dispersion of delta-MnO2, stirring for a period of time at 40-60 DEG C, then adding inorganic acid, and continuously stirring for a period of time at 40-60 DEG C; and 2) carrying out solid-liquid separation on the mixed solution obtained in the step 1), washing and drying the solid to obtain the water-resistant polycrystalline manganese oxide catalyst. The catalyst provided by the invention has a polycrystalline manganese oxide in which alpha and delta crystal forms coexist, and an interface structure at the boundary of the alpha crystal form manganese oxide and the delta crystal form manganese oxide.

The present invention provides a new method for synthesizing a class of dimethylsulfonium ylide compounds. Specifically, dimethyl sulfide and chloroacetate are used as raw materials, and in the presence of a catalyst, a chlorosulfonium salt is synthesized, and then hydrogen chloride is removed by an alkali to generate the target compound sulfonium ylide. The method has the advantages that the raw materials are easily obtained, the conditions are mild, the production safety is high, the yield is high, the reaction cost is reduced, it is easy to scale up, and it has high industrial application value.

The invention discloses a foamed asphalt mixture as well as a preparation method and application thereof, and relates to the technical field of asphalt preparation. The foamed asphalt mixture prepared by the preparation method disclosed by the invention is prepared from modified asphalt, pure water, aggregate, cement, modified zeolite, pentaerythritol tetra-3-mercaptopropionate and a nucleophilic reagent. The modified asphalt is obtained by mixing modified SBS and matrix asphalt; the modified SBS is obtained by reacting chlorosulfonated SBS with [(4-aminophenyl) (hydroxyl) methyl] diethyl phosphonate, brominating and reacting with dimethyl sulfide; the modified zeolite is obtained by reacting pretreated zeolite with carbon dioxide, grafting 2, 2, 6, 6-tetramethylpiperidine-4-yl 4-aminobenzoate, and then reacting with methacrylic anhydride. The foamed asphalt mixture prepared by the preparation method disclosed by the invention has good flame retardance, ageing resistance and mechanical properties.

The invention relates to a tebuconazole synthesis method, and belongs to the technical field of organic synthesis, the method flow comprises the following steps: Step 1: adding 1, 2, 4-triazole, DMF or NMP as a solvent, sodium hydroxide alkali liquor or potassium hydroxide alkali liquor, sodium iodide or potassium iodide as a catalyst and pentanone into a reaction flask, and heating to 80-90 DEG C; 2, methylation reagents are added in batches, the methylation reagents are preferably dimethyl sulfide sulfuric acid dimethyl ester onium salt, after addition is completed, heat preservation stirring is conducted, and the heat preservation time is 1-2 hours. P-chlorobenzyl cyanide and cyclopropyl methyl ketone are used as main raw materials, p-chlorobenzyl cyanide is subjected to halogenation at a benzyl position and then subjected to a Darzen reaction with cyclopropyl methyl ketone under the alkaline condition of potassium hydroxide to obtain an epoxide, a target product is obtained through one-pot cyano hydrolysis and deacidification under the acidic condition of sulfuric acid, the synthesis route is short, the process is simple, the raw material cost is low, and the method is suitable for industrial production. The process is simple and smooth, green and environment-friendly, and suitable for industrial large-scale production.

The invention provides a heterogeneous catalyst COFBMTD-PY as well as a preparation method and application thereof, belongs to the technical field of photocatalysts, and can solve the problems that the current thioether oxidation reaction needs to be operated under a high-temperature condition, the dosage of the catalyst is large, an additional cocatalyst is needed, and in the actual use process, most of the catalysts cannot be recycled and are not easy to recover, so that the cost is low, and the like. The loss of the catalyst is serious, and the reaction waste is increased. The heterogeneous catalyst COFBMTD-PY disclosed by the invention is constructed by taking 1, 3, 6, 8-tetra-(p-aminophenyl)-pyrene and 2 ', 5'-bis ((1H-imidazole-1-yl) methyl)-[1, 1 ': 4', 1 ''-terphenyl]-4, 4''-diformaldehyde as units, and the heterogeneous catalyst COFBMTD-PY has a structural formula shown in the specification. The heterogeneous catalyst COFBMTD-PY disclosed by the invention can be applied to catalysis of oxidation reaction of methyl thioether and derivatives thereof, and has the advantages that efficient conversion of thioether is realized, reaction selectivity is precisely regulated and controlled, sulfone generation caused by excessive oxidation is avoided, a cocatalyst or extra oxygen is not needed, and the catalyst can be repeatedly utilized.

The present invention discloses a 1,4-dicarbonyl compound, its preparation method and application. The 1,4-dicarbonyl compound has the structure shown in Formula I. The preparation method includes the following steps: S1. Compound a reacts with thionyl chloride and dimethylamine hydrochloride to form compound b; S2. Compound b reacts with iodine, magnesium chips and 4-bromo-1-butene to form compound c; S3. Compound c reacts with dimethyl sulfide to obtain the compound with the structure shown in Formula I. Among them, the preparation method of the 1,4-dicarbonyl compound of the present invention is simple in operation and relatively mild in reaction conditions, and has broad application prospects.

The present invention provides a dimethyl sulfide C(sp 3 )-H bond boride, synthesis method and application, belonging to the field of organic synthesis. The present invention relates to a methyl sulfide C (sp 3 The invention discloses a selective synthesis method of )-H bond boron compounds, wherein a methyl sulfide compound and a pinacol boron ester are reacted under the synergistic catalysis of a novel bipyridine ligand and a transition metal iridium catalyst. The synthesis method achieves high selectivity of methyl C (sp) from a methyl sulfide compound without a directing group without using a protecting group. 3 )-H bond borylation reaction, the product selectivity is high, the yield is generally 65-85%, the reaction conditions are mild, and the operation is simple.

The invention belongs to the technical field of dimethyl sulfoxide production, and particularly relates to a technology for producing dimethyl sulfoxide through dimethyl sulfide oxidation. According to the process, dimethyl sulfide is taken as a raw material, dimethyl sulfoxide is taken as a solvent, hydrogen peroxide is taken as an oxidizing agent, a micro-channel reactor is utilized to strengthen a reaction process, and the dimethyl sulfoxide is continuously produced under the conditions of low temperature and low system pressure. According to the method, the conversion rate of the raw materials is increased, the reaction conditions are mild, the reaction time is short, the reaction safety is high, post-treatment of a product after reaction is simple, and continuous production can be realized.

3-chloro-2-methyl phenyl dimethyl sulfide is a key intermediate for synthesizing tembotrions, and the target product 3-chloro-2-methyl phenyl dimethyl sulfide is finally synthesized by taking 3-chloro-2-methylaniline and sodium methyl mercaptide as raw materials through diazotization and methyl mercaptan. In order to solve the danger problem existing in the diazotization production process, the invention provides a production process for continuous production of 3-chloro-2-methylphenyldimethyl sulfide in the micro-channel reactor, and the production process has the advantages that compared with a traditional reaction kettle, the micro-channel reactor is provided with a reaction channel with a small diameter, so that the yield of 3-chloro-2-methylphenyldimethyl sulfide is increased; and the catalyst has the advantages of large specific surface area, large volume ratio, high mass transfer and heat transfer efficiency, good operability, no obvious amplification effect and the like. Particularly, the risk of over-temperature explosion in the diazotization reaction process is greatly reduced due to the efficient heat transfer efficiency and the tiny material holding amount of the microreactor.

This invention belongs to the field of pharmaceutical technology and relates to 2,3-dihydrofuran derivatives of general formula I, their stereoisomers, and pharmaceutically acceptable salts, hydrates, solvates, or prodrugs, wherein the substituents Ar1, R1, and R2 have the definitions given in the specification. This invention also relates to methods for preparing compounds of general formula I, and the related uses of the above compounds in the preparation, treatment, and prevention of inflammatory diseases.

This invention relates to a method for the electrocatalytic oxidation of anisole to anisole sulfoxide using iron-based complexes, belonging to the fields of homogeneous catalysts and electrocatalytic oxidation technology. The invention utilizes an iron-based complex formed by coordination between a tetraamide macrocyclic ligand (TAML-H4) and metallic iron as a homogeneous molecular catalyst, with water as the sole oxygen source, to construct an electrocatalytic anisole oxidation system. Through the synergistic effect of the catalyst and water, a proton-coupled electron transfer and single-electron oxidation process occurs at the anolyte, resulting in the loss of two electrons and two protons to generate a high-valence iron-oxygen active intermediate [Fe]. Ⅴ (O)(TAML)] – This invention achieves highly efficient and selective oxidation of anisole, generating the high-value-added product benzyl sulfoxide at the anode. It eliminates the need for additional strong oxidants, employs mild reaction conditions, boasts high atom economy, and is environmentally friendly, making it suitable for the green conversion of sulfides in the synthesis of fine chemicals. This provides a feasible pathway for the industrial production of sulfoxide compounds.

This invention relates to a photocurable composition comprising: cyanoacrylate A selected from the group consisting of n-hexyl cyanoacrylate, n-heptyl cyanoacrylate, n-octyl cyanoacrylate, and mixtures thereof; a free radical photoinitiator; a metallocene compound; compound B selected from the group consisting of boron trifluoride, boron trifluoride diethyl ether, boron trifluoride dihydrate, boron trifluoride ethanol, boron trifluoride methanol, boron trifluoride acetic acid, boron trifluoride butyl ether, boron trifluoride butanol, boron trifluoride propanol, boron trifluoride dimethyl sulfide, boron trifluoride acetonitrile, boron trifluoride tetrahydrofuran, and boron trifluoride isopropanol; and optionally a free radical polymerization inhibitor, provided that when the photocurable composition contains a free radical polymerization inhibitor, its weight content is 0.04 wt.% or less; wherein the molar content of compound B is greater than or equal to 0.141 mmol per 1 kg of composition; and wherein the molar ratio of metallocene compound / compound B ranges from 2 to 8.

The invention discloses a detection method for determining a degradation impurity dimethylamino formic acid in neostigmine methylsulfate, the detection method is carried out by using a high performance liquid chromatograph, a mobile phase is composed of a mobile phase A and a mobile phase B, and isocratic elution is adopted; the isocratic elution is adopted, the total volume of the mobile phase is 100%, the volume of the mobile phase A is 26%-30%, and the volume of the mobile phase B is 74%-70%; the detection method is carried out by using a high performance liquid chromatograph, a chromatographic column adopts acrylic acid amine bonded silica gel as a filling agent, and a mobile phase is composed of a phosphate buffer solution and acetonitrile. According to structural characteristics of products and properties of compounds, chromatographic conditions are optimized, so that a blank solvent and other components in a test sample have no interference on measurement of dimethylamino formic acid, detection specificity, sensitivity and accuracy are improved, and medicine quality is controlled more strictly.

The present invention belongs to the field of pharmaceutical technology, and specifically relates to a method for producing high-purity nifuratel. The method comprises the following steps: first, reacting an organic acid with hydrazine hydrate to generate a hydrazine salt; then, adding epoxypropyl methyl sulfide to the hydrazine salt to perform a hydrazine hydrolysis reaction to obtain a hydrazine hydrolyzate salt solution; then, using an alkali to liberate the hydrazine hydrolyzate; extracting the organic phase through a solvent; then, concentrating, cyclizing, and condensing the organic phase to obtain a crude nifuratel product; and finally, recrystallizing the organic phase to obtain a high-purity nifuratel product. The method saves the raw material hydrazine hydrate, is safe and environmentally friendly, is simple to operate, and is easy to industrialize. The purity of the crude nifuratel obtained can reach 99%, and the purity of the nifuratel product after recrystallization can reach 100%.

The application discloses a method for synthesizing benzyl sulfoxide by selectively oxidizing benzyl sulfide, belongs to the technical field of fine organic synthesis, and can solve the problems of a long synthesis process, complex catalyst preparation and long reaction time in the synthesis of benzyl sulfoxide at present. The method uses benzyl sulfide as raw material, uses ozone as an oxidant, introduces tert-butyl alcohol as an inhibitor to control the reaction process, and uses ethyl acetate as a reaction solvent, and benzyl sulfoxide is prepared through selective oxidation. The innovative process has the advantages of mild process conditions, environmental friendliness, no need to add any catalyst and high product yield. The method has great potential and value in the industrial application field.

The invention provides a low-byproduct methyl mercaptan synthesis process. The byproduct of dimethyl sulfide is inevitably generated in the process of generating methyl mercaptan from hydrogen sulfide and methanol. The method comprises the following steps: filling a thioether conversion catalyst at the front end, introducing methyl sulfide with a large proportion of hydrogen sulfide ratio, connecting a multi-stage methyl mercaptan synthesizer in series at the rear end, supplementing and introducing methanol, reacting excessive hydrogen sulfide at the front end with methanol to generate methyl mercaptan, gradually heating the multi-stage methyl mercaptan synthesizer from front to back, filling a high-selectivity catalyst in the methyl mercaptan synthesizer at the front end, the last-stage methyl mercaptan synthesizer is filled with a high-conversion-rate catalyst, hydrogen sulfide is slightly insufficient, and hydrogen sulfide is basically consumed. According to the designed methyl mercaptan synthesis process, the byproduct of dimethyl sulfide is reduced, the amount of tail gas is reduced, compression and recycling of hydrogen sulfide are avoided, gas-liquid entrainment is reduced while energy consumption is reduced, condensation of the product is facilitated, and the yield of methyl mercaptan is increased.

The invention discloses a method for preparing 2-methylsulfoxide-4-trifluoromethyl benzoic acid methyl ester. In an organic solvent, 2-amino-4-trifluoromethyl-benzoic acid methyl ester is used as a raw material, and the product 2-methylsulfoxide-4-trifluoromethyl benzoic acid methyl ester is obtained by diazotization and methyl sulfide etherification in a one-pot reaction at a certain temperature. The inventive method has multiple raw material sources and obvious cost advantages. At the same time, the use of traditional malodorous reagents such as dimethyl disulfide or sodium methyl mercaptide is avoided. The preparation method is safer and more convenient, has a high total yield, and reduces the three wastes, which is conducive to industrialization.