47 results about "Isopropyl ether" patented technology

The application belongs to the field of organic synthesis, and particularly relates to a synthesis method of 2-(3,3-dimethylbutyl)pyridine. 2-vinylpyridine, brominated tertiary butane, a mixed solution of dimethyl ether and isopropyl ether as a reaction system solvent, nickel iodide as a nickel salt, bipyridine as a ligand, dicyclohexylmethylamine as a base in the system, 2,6-dimethyl-3,5-diethyl-1,4-dihydropyridine as a reducing agent, a photocatalyst 2,4,5,6-tetrakis(9 ‑ Carbazole) - m-phenylenedinitrile, under the condition of room temperature and nitrogen atmosphere, a reduction cross-coupling reaction is used to synthesize 2-(3,3-dimethylbutyl)pyridine. The application uses inexpensive nickel metal as a catalyst, constructs a cross-coupling reaction of carbon-carbon bond, and has the advantages of mild reaction condition, high economy and the like.

The application belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of methoxychlorpromazine monohydrochloride monohydrate. The method comprises the following steps: step 1, methoxychlorpromazine base is dissolved in a polar solvent, and hydrochloric acid is added to obtain a mixed solution; step 2, a poor solvent of methoxychlorpromazine monohydrochloride monohydrate is added to the mixed solution, crystallization is carried out, and separation is performed, and methoxychlorpromazine monohydrochloride monohydrate is obtained; the poor solvent is selected from one or a mixture of two or more of isopropyl alcohol, n-butyl alcohol, acetone, butanone, ethyl acetate, butyl acetate, dichloromethane, trichloromethane, toluene, methyl tert-butyl ether, isopropyl ether and diethyl ether. The method has the advantages of simple process, good repeatability, easy operation, high yield, product purity of more than 99.8%, complete compliance with the requirements of European Pharmacopoeia 9.0 and US Pharmacopoeia USP43, and suitability for industrial production.

The invention discloses a post-treatment method of a polypeptide lysate. The method belongs to the field of polypeptide drug preparation. The method comprises the following steps: firstly, concentrating a polypeptide lysate, and then spraying pre-cooled isopropyl ether or methyl tert-butyl ether into the concentrated solution until a large amount of samples are separated out; and carrying out solid-liquid separation by using a filter bag type centrifuge, and carrying out on-line leaching by using isopropyl ether or methyl tert-butyl ether. The solid obtained through the method is large in particle size, solid-liquid separation is facilitated, the operation time is greatly shortened, and the method is extremely beneficial to large-scale industrial production. In addition, an on-line leaching mode is adopted, so that contact with people is avoided, and green industrial production is facilitated.

The invention relates to the technical field of pharmaceutical chemical engineering, in particular to a preparation method of a 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolone [3, 4-B] pyridine-3-formonitrile crystal form, which comprises the following steps: mixing a 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolone [3, 4-B] pyridine-3-formonitrile solid with isopropyl ether, and stirring for dissolving; and cooling, growing crystals, performing suction filtration, washing and drying. The preparation method of the 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolone [3, 4-B] pyridine-3-formonitrile crystal form solves the problems that the original crystal form of the existing 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolone [3, 4-B] pyridine-3-formonitrile is small in density, large in volume and easy to generate electrostatic effect, and the crystal form is easy to agglomerate to wrap impurities and is not beneficial to subsequent API (American Petroleum Institute) purification.

The present application relates to the technical field of medicine and chemical industry, and in particular to a preparation method of a 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolyl[3,4-B]pyridine-3-carbonitrile crystal form, which comprises the following steps: mixing 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolyl[3,4-B]pyridine-3-carbonitrile solid with isopropyl ether, and then stirring and dissolving; cooling and crystallizing, and then drying after filtration and washing to obtain the product. The preparation method of the 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolyl[3,4-B]pyridine-3-carbonitrile crystal form solves the problems of the original crystal form of 5-fluoro-1-(2-fluorophenyl)-1H-pyrazolyl[3,4-B]pyridine-3-carbonitrile, such as small density, large volume and easy electrostatic effect, and the crystal form is easy to form a group and wrap impurities, which is not conducive to subsequent API purification.

The invention belongs to the technical field of reverse osmosis membranes, and discloses a preparation method of a hyperconcentration SD reverse osmosis membrane and the hyperconcentration SD reverse osmosis membrane. The preparation method comprises the following steps: (1) adding a polymer into an organic solvent in a heating and stirring state to obtain a mixed solution; (2) cooling the mixed solution, and continuously adding a pore-foaming agent to obtain a precursor solution; (3) performing vacuum defoaming treatment on the precursor solution to obtain a membrane casting solution; (4) loading the membrane casting solution on a carrier, and then carrying out gel bath treatment to obtain a base membrane; and (5) sequentially infiltrating the base membrane in a water phase solution and an organic phase solution to perform polyamide treatment, thereby obtaining the super-concentrated SD reverse osmosis membrane. Wherein the water phase solution is prepared from m-phenylenediamine and piperazine; the organic phase solution comprises a first component and a second component, the first component comprises trimesoyl chloride, and the second component comprises at least one of xylene, acetone, isopropyl ether, ethyl acetate and paraphthaloyl chloride.

The invention discloses a process for separating and extracting isopropyl ether in bisphenol A wastewater. The process comprises the following steps: step 1, preheating the bisphenol A wastewater through a preheater; 2, conveying the preheated bisphenol A wastewater into a rectifying tower for rectification; 3, extracting an isopropyl ether mixture from a tower top gas outlet of the rectifying tower; and 4, separating acetone from the isopropyl ether mixture through an extractive distillation tower, and dehydrating and drying to obtain isopropyl ether. According to the method, bisphenol A wastewater is preheated by a preheater and then conveyed into a rectifying tower to be rectified; and extracting an isopropyl ether mixture from a tower top gas outlet of the rectifying tower, separating acetone through an extractive rectifying tower, and dehydrating and drying to obtain isopropyl ether. The content of phenol in isopropyl ether separated by using the method is less than 0.05%, and the raw material requirements of subsequent processes are met.

The invention provides a device and a method for reducing the COD (Chemical Oxygen Demand) content of wastewater of an epoxypropane device. The treatment method comprises the following steps: carrying out negative pressure cyclone separation on flashed saponification wastewater to obtain a first gas phase and a first liquid phase; condensing the first gas phase to obtain a second gas phase and a second liquid phase; carrying out gas-liquid separation on the second gas phase to obtain an oil phase and a third gas phase; and mixing the second liquid phase and the oil phase, standing and separating to obtain dichloro isopropyl ether and a water phase. The COD (Chemical Oxygen Demand) content and the dichloro isopropyl ether content of the treated saponified wastewater are reduced.

The invention relates to a method for synthesizing polymeric dyes by polymerizing polymerizable monomers bearing polymerizable functional groups (e.g., acrylates, methacrylates, acrylamides or methacrylamides) and chromophore functional groups, in which the polymerization is carried out in a solvent selected from a mixture of methyl ethyl ketone and ethanol or acetonitrile, and the purification of the resulting polymeric dye is carried out with a solvent selected from the group consisting of diisopropyl ether, methyl tert-butyl ether, dimethyl carbonate, ethyl acetate and water. The invention also relates to the resulting polymeric dyes and to ink compositions comprising same. In particular, the following polymeric dyes are disclosed:.

This application discloses a method for preparing diisopropyl ether from propylene hydration. A raw material containing propylene and water is contacted with a catalyst and reacted to obtain a product containing diisopropyl ether. The catalyst consists of a support and an active component supported on the surface of the support; the support is an Hβ molecular sieve; the active component is selected from at least one of CuO, Fe2O3, and CoO. The reaction is fast, with high yield, and can be applied to large-scale production. The catalyst preparation method is stable, controllable, and reproducible.

The invention relates to an industrial preparation method of sevoflurane. Specifically, the invention relates to a preparation method of sevoflurane, and the method comprises a step of reacting chloromethyl hexafluoroisopropyl ether with potassium fluoride and pentaerythritol, and a step of preliminary impurity removal and rectification. The sevoflurane prepared by the preparation method disclosed by the invention has the advantages of high purity, high yield and less waste, and is beneficial to industrial production.

The invention relates to the field of magnesia carbon bricks and discloses a novel magnesia carbon brick for a converter mouth and a preparation method thereof.The novel magnesia carbon brick for the converter mouth is prepared from, by weight, 73-80 parts of fused magnesia particles, 15-22 parts of fused magnesia fine powder, 3-5 parts of crystalline flake graphite, 4-6 parts of phenolic resin, 1-4 parts of modified carbon fibers, 0.5-3.5 parts of alpha-Al2O3 micro powder and 2-5 parts of additives; the modified carbon fiber is prepared by carrying out boron nitride coating on carbon fiber by adopting a boric acid and urea impregnation reaction process and then carrying out high-temperature carbonization and cracking by adopting phenolic resin to further carry out cracking carbon coating; the admixture is prepared by the following steps: preparing polyborosiloxane from octamethylcyclotetrasiloxane and boric acid as raw materials, preparing titanium dioxide sol from titanium tetrachloride and isopropyl ether as raw materials and dichloromethane as a solvent by adopting a non-hydrolytic sol-gel method, and then mixing the polyborosiloxane and the titanium dioxide sol. The magnesia carbon brick prepared by the method is high in overall strength and good in thermal shock resistance and oxidation resistance.

The purpose of the present invention is to provide a means for obtaining SMTP from a fermentation product including SMTP via a method that can easily be scaled up; to provide an SMTP crystallization method; or to provide a means for obtaining SMTP via a method including SMTP crystallization. The present invention provides an SMTP production method including: a step I for putting a Stachybotrys microspora fermentation product in contact with an aqueous solvent having a pH of 9 or greater and obtaining an extract liquid including SMTP; a step II for supplying the extract liquid obtained in step I for purification and obtaining a purified product; and a step III for crystallizing the SMTP included in the purified product obtained in step II in a crystallization solvent including one or more selected from the group consisting of ethyl acetate, butyl acetate, acetone, 2-butanone, diisopropyl ether, diethyl ether, methyl-tert-butyl ether, and acetonitrile. Alternatively, provided is an SMTP production method including a step for crystallizing SMTP having a purity of 70% or greater in a solvent including one or more selected from the group consisting of ethyl acetate, butyl acetate, acetone, 2-butanone, diisopropyl ether, diethyl ether, methyl-tert-butyl ether, and acetonitrile. Alternatively, provided is an SMTP production method including putting a Stachybotrys microspora fermentation product in contact with an aqueous solvent having a pH of 9 or greater and obtaining an extract liquid including SMTP.

The invention belongs to the field of organic synthesis, and particularly relates to a synthetic method of a diaryl methylsilane compound. In an inert gas environment, benzylsilane compounds as shown in formulae 1 and 4 and aryl halides (R7 = Br, 1) as shown in formulae 2 and 5 are mixed and heated with isopropyl ether in the presence of an allyl palladium (II) chloride dipolymer, 4, 6-di (diphenylphosphine) phenazine and bis (trimethylsilyl) caesium amine to synthesize the diaryl methylsilane compounds as shown in formulae 3 and 6. According to the invention, the coupling reaction of the benzyl silane compound and the aryl halide is realized by adopting a catalytic amount of the allyl chloride palladium (II) dimer, and the palladium catalyst shows obvious catalytic performance.

The invention discloses a preparation method of a photoacid generator 2-((-adamantane-1-carbonyl) oxy)-1, 1-difluoroethane-1-sulfonate diphenyl (p-tolyl) sulfonium salt, and belongs to the technical field of synthesis of photoacid generators. The preparation method comprises the following steps: dissolving methyl fluorosulfonyl difluoroacetate in isopropyl ether, adding isopropanol at normal temperature, dropwise adding triethylamine at low temperature, and performing reflux reaction after dropwise adding to prepare sulfonate; dissolving the sulfonate in isopropanol, reacting with sodium borohydride at low temperature, and reducing the contained ester group into hydroxyl to obtain a compound 1, 1-difluoro-2-hydroxyl ethanesulfonic acid sodium salt; the preparation method comprises the following steps: preparing 1-adamantanecarboxylic acid from 1-adamantanecarboxylic acid, performing esterification reaction on hydroxyl contained in the molecule and 1-adamantanecarboxylic acid under the action of trifluoroacetic acid and trifluoroacetic anhydride to prepare anions, stirring the anions and (4-methylphenyl) diphenylsulfonium trifluoromethane sulfonate in an organic solvent, and performing post-treatment and purification after the reaction is finished to obtain a pure product. The preparation steps are simple, and the reaction is efficient.

The present application relates to the technical field of separation and purification of Schizonepeta tenuifolia, and is a kind of Schizonepeta tenuifolia phenylpropanoid compound, its preparation method and application, Schizonepeta tenuifolia is extracted by heating reflux with ethanol solution and recovered under reduced pressure, and concentrated, the total extract of Schizonepeta tenuifolia is extracted and concentrated with petroleum ether, dichloromethane and ethyl acetate in turn, the extract of ethyl acetate part is separated by gradient elution, the third fraction is separated by gradient elution, the first fraction is separated by gradient elution, the sixth fraction is separated by gradient elution, and phenylpropanoid compound one and phenylpropanoid compound two are obtained at 12.1 minutes and 13.4 minutes, respectively. The present application discloses phenylpropanoid compound one and phenylpropanoid compound two separated from Schizonepeta tenuifolia for the first time, and in vitro anti-inflammatory pharmacodynamic experiments are carried out on the two compounds, which prove that they have a certain inhibitory effect on RAW264.7 cells, and can be applied to the preparation of anti-inflammatory drugs.

The present disclosure relates to an industrial production method for sevoflurane. Specifically, the present disclosure relates to a method for preparing sevoflurane, comprising the steps of reacting chloromethyl hexafluoroisopropyl ether with potassium fluoride and pentaerythritol, followed by preliminary impurity removal and distillation. The sevoflurane produced by the method described herein has high purity, high yield, and minimal waste, thus facilitating industrial production.

The invention discloses a synthesis method for preparing an aryl phosphine-oxazoline ligand, which comprises the following steps: sequentially adding an alkyl alcohol alkali metal compound, a first solvent and a compound B into a reaction container, stirring, continuously adding a compound A, carrying out heat preservation reaction at the reaction temperature of 0-100 DEG C, and synthesizing the aryl phosphine-oxazoline ligand by a one-pot method, the alkyl alcohol alkali metal compound is selected from potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, potassium isopropoxide, sodium isopropoxide, lithium isopropoxide, sodium ethoxide and sodium methoxide; the first solvent is selected from the group consisting of tetrahydrofuran, diethyl ether, 1, 4-dioxane, 2-methyltetrahydrofuran, ethylene glycol dimethyl ether, cyclopentyl methyl ether, methyl tert-butyl ether and isopropyl ether. The method has the advantages of few reaction steps, easily available raw materials, mild reaction conditions, high yield, simple separation and convenient purification.

The present disclosure relates to a method for preparing caronic anhydride. The method comprises cyclizing caronic acid to obtain crude caronic anhydride; and using isopropyl ether to recrystallize the crude caronic anhydride to obtain caronic anhydride.

The application belongs to the field of organic synthesis, and particularly relates to a method for synergistically synthesizing 1,1-diaryl-2-alkyl compounds by using nickel and light. The method comprises the following steps: using styrene derivatives, p-bromoacetophenone and tert-butyl bromide as raw materials, and mixing a metal nickel catalyst (nickel bis(acetylacetone)), a photocatalyst (1,2,3,5-tetrakis(carbazole-9-yl)-4,6-dicyano benzene), a nitrogen ligand ((4S,4'S)-1,1'-bis(3-tert-butylphenyl)-4,4',5,5'-tetrahydro-4,4'-bis[(1S)-1-methylpropyl]-2,2'-bis-4H-imidazole), a Bronsted base (N,N-dicyclohexylmethylamine), a reducing agent (1,4-dihydropyridine derivatives) and an organic solvent (glycol dimethyl ether, isopropyl ether) to generate a three-component cross-coupling reaction and synthesize 1,1-diaryl-2-alkyl compounds with one chiral center. The three-component cross-coupling reaction is realized by using nickel and light, so that the use of a metal reducing agent is avoided, and the preparation raw materials are not needed. The method has the advantages of high reaction yield, high enantiomeric selectivity, fast reaction speed, easy-to-obtain raw materials and simple process.

The utility model relates to a peculiar smell removing device for epoxypropane saponification residual liquid. According to the technical scheme, a lime milk storage tank and a chloropropanol storage tank are connected to a saponification tower through pipelines respectively, and the bottom of the saponification tower is connected with a saponification waste liquid tank; the lower end of the diffusion tower is connected to a water treatment system through a pipeline, the upper end of the diffusion tower is connected to a separation tank through a pipeline and a second condenser, and the lower side of the separation tank is connected with a dichloro isopropyl ether storage tank through a pipeline and a dichloro isopropyl ether delivery pump. The device has the beneficial effects that low-pressure steam fed from the bottom of the diffusion tower is evacuated under the action of the vacuum pump, a gas phase at the top of the diffusion tower enters the second condenser and is condensed under the cooling action of circulating water to enter the separation tank, and the dichloroisopropyl ether sinks to the bottom and is treated by the dichloroisopropyl ether delivery pump, so that the quality of the dichloroisopropyl ether is improved. Dichloro isopropyl ether is extracted, cooled, collected, separated and treated, so that peculiar smell is removed, and the product quality is improved.

The invention discloses a double-bowl-shaped molecular container based on isoanion induction as well as a preparation method and application of the double-bowl-shaped molecular container, and relates to the technical field of supramolecular materials. The method comprises the following steps: dissolving 1, 2, 3, 4, 5, 6-hexabromomethyl benzene and 9-(2-(1H-imidazole-1-yl) ethyl)-9H-carbazole into acetonitrile, so as to obtain a first intermediate product; dissolving the first intermediate product in methanol, and dropwise adding a saturated ammonium hexafluorophosphate methanol solution while stirring to obtain a second intermediate product; and dissolving the second intermediate product and tetrabutylammonium bromide in acetonitrile, filtering, adding the filtrate into isopropyl ether, sealing, and standing at room temperature for 12-24 hours to obtain the double-bowl-shaped molecular container. Under the common induction of bromide ions and hexafluorophosphate ions, the six arms are alternately folded up and down three times to form the double-bowl-shaped molecular container.

The invention discloses a method for accurately detecting impurity metal elements in high-purity gallium. The method comprises the following steps: completely dissolving high-purity gallium in mixed acid, adding ammonia water, standing, and fully precipitating; taking out supernate obtained by standing and precipitating, adding the mixed acid again, fully mixing, and concentrating to obtain a to-be-detected precursor; adding ultrapure water and an internal standard substance into the to-be-detected precursor, uniformly mixing to obtain a to-be-detected sample, and detecting by ICP-MS (Inductively Coupled Plasma Mass Spectrometry) to obtain the target product. According to the method, a solvent-precipitation separation-detection process is constructed through the synergistic effect of all the steps, the problem that the detection result is inaccurate due to impurities introduced by isopropyl ether is effectively avoided, and the method does not need to adopt a GD-MS or a customized chlorination separation device, so that the detection cost is greatly reduced, and the detection precision is effectively ensured.

The invention relates to the technical field of synthesis of pesticide intermediates, in particular to an industrial production process of 2, 4-dichloro-5-nitrophenyl isopropyl ether, which comprises the following steps: reacting 2, 4-dichloro-5-nitrophenol with caustic soda liquid to generate sodium salt by taking methylbenzene as a solvent, then carrying out azeotropic dehydration, and directly adding a catalyst to carry out etherification reaction with isobromopropane to obtain 2, 4-dichloro-5-nitrophenyl isopropyl ether. The catalyst is 2, 4-dichloro-5-nitrophenyl isopropyl ether. The method realizes the recycling of isobromopropane and the recovery of the byproduct bromine salt, reduces the production cost, is more environment-friendly, is short in reaction time, and is suitable for industrial large-scale production.

According to the method for treating the lithium precipitation mother liquor based on eutectic solvent extraction-precipitation, trioctylphosphine oxide and tetradecyl phosphoric acid are mixed to form a eutectic solvent system, trioctylphosphine oxide serves as a hydrogen bond acceptor, and the property of an eutectic solvent extraction-precipitation agent is regulated and controlled. Compared with an extraction-precipitation strategy of single tetradecyl phosphoric acid, by introducing trioctylphosphine oxide, the particle size of the precipitate is remarkably increased, an organic solvent is prevented from being used in the reverse extraction process, and meanwhile, the high-selectivity precipitation capacity of tetradecyl phosphoric acid TDPA to lithium is kept. The lithium can be enriched without isopropyl ether in the reverse extraction process, so that the isopropyl ether evaporation process in the extraction-precipitant circulation process is reduced, the overall energy consumption is reduced, and meanwhile, the performance attenuation of the extraction-precipitant caused by isopropyl ether oxidation is also avoided.

The invention belongs to the technical field of fine chemical engineering, and relates to a method for adsorbing and removing isopropyl ether and / or acetone in isopropanol, which comprises the step of contacting MAF-6 with an isopropanol solution containing isopropyl ether and / or acetone. Compared with the prior art, the method has the advantages that by utilizing the characteristic that the adsorption selectivity of MAF-6 to isopropyl ether and acetone is far greater than that of isopropyl alcohol, MAF-6 is adopted as an adsorbent in an industrial-grade isopropyl alcohol raw material with relatively high purity, so that clear separation and efficient trapping of isopropyl alcohol, isopropyl ether and acetone impurities are realized, and the purpose of refining isopropyl alcohol is achieved. The isopropyl ether in the isopropyl alcohol treated by the adsorption separation method provided by the invention can be removed to be less than 1ppm, and the acetone can be reduced to be less than 2ppm, so that the purity requirement of high-grade electronic-grade isopropyl alcohol is met.

The invention relates to the technical field of VOCs treatment, and discloses hydrophobic activated carbon and a preparation method and application thereof.The method comprises the steps that formed activated carbon is dried and then mixed with a short-chain polymer and an organic solvent, then rotary evaporation drying and vacuum drying are conducted, and the hydrophobic activated carbon is obtained; the short-chain polymer is selected from poly (butyl acrylate), polyvinyl acetate, polylactic acid, polysiloxane, polyethylene, polypropylene, polyisobutene, polystyrene, poly (4-tert-butylstyrene), polybutadiene, polyvinyl ether, polyvinyl formal, polyvinyl carbonate, polyepichlorohydrin, polyethyleneimine and polyetherimide; the component A is at least one of polymethyl isopropyl ether and polyglycolide. The formed activated carbon is used as a modification starting point, the short-chain polymer is used as a modifier, and through specific selection of the short-chain polymer and rotary evaporation drying and vacuum drying, the prepared hydrophobic activated carbon is excellent in hydrophobic performance and excellent in adsorption effect on VOCs in high-humidity crude oil volatile gas.

This invention discloses an esomeprazole sodium and its purification method, relating to the field of drug synthesis technology. The purification method includes the following steps: S1, mechanically grinding crude esomeprazole sodium with a composite solid purification additive to obtain an activated mixture; the composite solid purification additive is a composition of diisopropyl tartrate and hydroxypropyl-β-cyclodextrin, and the mass ratio of diisopropyl tartrate to hydroxypropyl-β-cyclodextrin is (1~5):(2~4); S2, adding a washing solvent to the activated mixture and stirring and washing, then performing solid-liquid separation to obtain a solid wet product; the washing solvent includes ethyl acetate, methyl tert-butyl ether, or isopropyl ether; S3, drying the solid wet product to obtain purified esomeprazole sodium. This purification method is not only simple in process and has a high product yield, but also does not introduce new impurities, and the product has high optical and chemical purity.

The present invention provides a biphenyl diphenol-based aluminum catalyst for preparing thymol, a preparation method thereof, and a preparation method of thymol and an application method thereof. The present invention prepares a catalyst by using a biphenyl diphenol compound and an aluminum-containing compound (such as alkyl aluminum or aluminum hydride), and then uses the catalyst to catalyze an alkylation reaction of m-cresol and propylene to prepare thymol. The catalytic effect can be further improved by adding isopropyl ether or isopropyl ester. The method of the present invention has the advantages of mild reaction conditions, high product selectivity, etc., and is particularly suitable for industrial production.

The present disclosure relates to a method for preparing sevoflurane and its intermediates. Specifically, the present disclosure relates to a method for preparing sevoflurane, which includes steps such as reacting hexafluoroisopropanol with dimethoxymethane in the presence of a Lewis acid catalyst to prepare methoxymethylidene hexafluoroisopropyl ether. The sevoflurane prepared by this method has high purity and few impurities.