81 results about "Ethyl formate" patented technology

The invention relates to the technical field of microorganisms, in particular to an ethyl carbamate degrading bacterium and application thereof.The ethyl carbamate degrading bacterium is pichia kudriavzevii K44 and is preserved in the China Center for Type Culture Collection on April 25, 2025, the preservation date is April 25, 2025, and the biological preservation number is CCTCC NO: M 2025887. The ethyl carbamate degrading bacterium can obviously degrade ethyl carbamate in a yellow rice wine fermentation system, and a scientific basis is provided for safe production and quality improvement of traditional fermented food.

The invention relates to the technical field of fibers, and discloses an easily biodegradable polyester-nylon composite fiber and a preparation process thereof.The preparation method comprises the steps that 2-(2-acrylamido ethyl formate) benzoic acid is subjected to graft modification to obtain modified polylactic acid, and the modified polylactic acid, polyethylene glycol terephthalate PET and nylon 66 resin are subjected to blending melt spinning to obtain the polyester-nylon composite fiber. The modified polylactic acid improves the compatibility between the PET and the nylon 66 resin, so that the polyester-nylon composite fiber has higher mechanical properties, and the tensile strength and the elongation at break are obviously improved. The polylactic acid has better biodegradability, and the introduced ester group also has biodegradability, so that the biological decomposition rate of the fiber is improved. The modified polylactic acid contains a large amount of hydrophilic carboxyl and amido bonds, so that the moisture regain of the composite fiber is improved, and the modified polylactic acid can be better applied to hydrophilic moisture absorption fiber textiles.

The invention discloses an analysis method for determining multiple components of white spirit by high performance liquid chromatography-tandem mass spectrometry, and relates to the technical field of white spirit analysis and detection, and the analysis method comprises the following steps: firstly, preparing an ethyl carbamate precursor substance standard stock solution and a mixed standard intermediate solution, and diluting the mixed standard intermediate solution step by step to obtain a mixed standard working solution; then determining chromatographic and mass spectrometry conditions, wherein BEH Ami chromatographic column is adopted as the chromatographic condition, and 0.1% formic acid water-acetonitrile is adopted as a mobile phase for gradient elution; a mass spectrum condition adopts a multi-reaction monitoring mode under an electrospray positive ion mode; drawing a quantitative calibration curve; finally, preparing a to-be-detected sample for content determination. According to the analysis method for determining the multiple components of the Baijiu through the high performance liquid chromatography-tandem mass spectrometry, through chromatographic condition optimization and mass spectrometry parameter innovation, the detection efficiency is improved, peak area data of urea, citrulline and arginine can be synchronously obtained through single sample injection, the analysis time is short, and quantification is accurate.

The invention discloses quick heat-conducting precoated sand and a preparation process thereof, and relates to the technical field of precoated sand, the quick heat-conducting precoated sand comprises the following raw materials by weight: 100-105 parts of crude sand, 6-8 parts of a modified resin prepolymer, 2-4 parts of modified POE, 3.5-4.5 parts of a lubricant, and 3-5 parts of nano silicon nitride. The modified POE has a relatively strong high-temperature toughening effect on the modified resin prepolymer, can also form chemical crosslinking with the modified resin prepolymer, and has relatively strong compatibility with other raw materials in the precoated sand. The modified resin prepolymer is obtained by heating and ring-opening polymerization of a benzoxazine monomer obtained by reaction of 5-nitrosalicylaldehyde, 2, 4-bis (trifluoromethyl)-5-pyrimidinyl ethyl formate, paraformaldehyde, furfuryl amine and the like, the curing temperature of the modified resin prepolymer is reduced, the thermal stability is improved, and improvement of the high temperature resistance of the precoated sand is facilitated.

The invention discloses a preparation method of a molecularly imprinted magnetic covalent organic framework nano-material, which comprises the following steps: adding Fe3O4 nano-particles, ethyl carbamate, substituted triazine aromatic amine, 2, 4, 6-trihydroxy trimesic aldehyde and 1, 3, 5-triazine-2, 4, 6-tricarboxaldehyde into dimethyl sulfoxide, mixing, then adding anhydrous acetic acid, stirring and reacting at room temperature, filtering, washing, and drying to obtain the molecularly imprinted magnetic covalent organic framework nano-material. After the reaction is finished, carrying out magnetic separation to obtain Fe3O4 (at) COFs; washing the Fe3O4 (at) COFs with an ethanol solution, washing the Fe3O4 (at) COFs with water, and drying the washed Fe3O4 (at) COFs to obtain a molecularly imprinted magnetic covalent organic framework nano material MIPs-Fe3O4 (at) COFs; compared with the prior art, after the prepared MIPs-Fe3O4-coated COFs are repeatedly used for 10 times, the removal efficiency of the prepared MIPs-Fe3O4-coated COFs on ethyl carbamate still can reach 97% or above, and the removal efficiency of the prepared MIPs-Fe3O4-coated COFs on ethyl carbamate is improved.

This invention discloses a method for preparing sodium houttuynia cordata, comprising the following steps: adding sodium methoxide and toluene to a reaction vessel, heating, then slowly adding nonanone and ethyl formate, and after the addition is complete, reacting with a gradient cooling process, and post-processing to obtain an aqueous phase containing intermediate I; adding the aqueous phase containing intermediate I and toluene to the reaction vessel, stirring, cooling, and rapidly introducing liquid sulfur dioxide, continuously stirring and reacting at 0-10°C for 5-15 minutes, cooling, and filtering to obtain crude sodium houttuynia cordata. The preparation method of this invention directly introduces liquid sulfur dioxide during the sulfonation reaction, greatly shortening the process time, while achieving high product yield and purity, and requiring less sulfur dioxide. Furthermore, in the post-processing of sodium houttuynia cordata, adding toluene to the reaction solution beforehand can effectively transfer the generated impurities to the toluene; recrystallization using a 50 v / v% ethanol aqueous solution removes water-soluble and oil-soluble impurities while further reducing the risk of fire and explosion during centrifuge operation.

The invention discloses Leishan fish sauce sour essence as well as a preparation method and application thereof. The leishan fish sauce acid essence is prepared from ethyl acetate, absolute ethyl alcohol, ethyl isovalerate, ethyl hexanoate, isoamyl alcohol, furfuryl alcohol, ethyl lactate, ethyl caprylate, acetic acid, diethyl succinate, methyl salicylate, ethyl benzoate, ethyl laurate, hexanoic acid, phenethyl alcohol, 4-methyl guaiacol, ethyl myristate, ethyl palmitate, ethyl oleate, capsicum oleoresin, ethyl phenylacetate and ginger oil. And lactic acid, glycerol triacetate, ocimene, ethyl isovalerate, ethyl butyrate, anethole and phenylacetaldehyde. The Leishan fish sauce sour essence disclosed by the invention is soft and harmonious in overall fragrance, natural and vivid, still has stable flavor characteristics at high temperature, can make up the problem of flavor deficiency in sour soup products, realizes accurate reproduction and controllable release of composite fragrance, improves the standardization level of products, and effectively improves the preference degree of consumers.

The utility model discloses a continuous extraction and purification device for ethyl formate, comprising: a main body component, the main body component comprising a support seat, a purification bottle body and a support top; an adjustment component, the adjustment component comprising a support plate, a rotating rod, a mixing rod, a support frame, a turntable, a first fixed frame, a first clamp ring, a second fixed frame and a second clamp ring; one end of the bottom of the support top is connected to the turntable, the support frame is rotatably connected to the outer surface of the turntable, the bottom of the support frame is connected to the support plate, and the middle part of the bottom end of the support plate is installed with a rotating rod. In order to solve the problem that in actual use of the existing ethyl formate extraction and purification device, the ethyl formate to be processed is usually uniformly poured into the bottle body, the internal mixture is manually mixed with a glass rod, and the bottle body is placed in the purification device for purification. If the mixture needs to be repeatedly added, the bottle body needs to be repeatedly taken, which is inconvenient to operate and use, and greatly reduces the work efficiency.

The present invention relates to the technical field of drug intermediate synthesis, and particularly relates to a preparation method of posaconazole starting material SM3. CeCl3·7H2O and sodium borohydride are added to compound POS-1 for an asymmetric reduction reaction to obtain compound POS-2. Compound POS-2 reacts with 3,5-bis(trifluoromethyl)benzenesulfonyl chloride to obtain compound POS-3. Hydrazine hydrate attacks from the back of compound POS-3 with a larger steric hindrance to undergo an SN2 reaction to obtain a stereoselectively specific compound POS-4. Compound POS-4 then reacts with ethyl formate and forms a salt with oxalic acid to obtain the product posaconazole starting material SM3. By means of asymmetric reduction of carbonyl groups and selective nucleophilic substitution, the present invention effectively avoids the chiral resolution step, thereby reducing the content of isomeric impurities. The prepared product not only has a high ee value, but also the yield is significantly improved, thereby greatly reducing the production cost.

The invention discloses a dual stimulus-responsive supramolecular gel temporary plugging agent and a preparation method thereof, and relates to the technical field of oil-gas field development. The supramolecular gel temporary plugging agent comprises the following components in percentage by mass: 5wt%-10wt% of a tertiary amine surfactant; the temperature response authigenic acid accounts for 0.2 wt%-2wt%; and the balance of water. Wherein the tertiary amine surfactant is prepared by reacting fatty acid and N, N-dimethyl-1, 3-diaminopropane according to the molar ratio of 1: 1, and the temperature response authigenic acid is composed of methyl formate, ethyl formate, methyl acetate, ethyl acetate and the like; the dual-stimulus-responsive supramolecular gel temporary plugging agent disclosed by the invention has the plugging strength of 4.3 MPa, takes water as a solvent, and is simple in process, high in yield, strong in environmental protection property, stable in performance and low in cost.

The application discloses a kind of pyrimidine-substituted 1,2,4-triazole derivatives, it is characterized in that, with the structure expressed in general formula I or II:Wherein, R1 is hydrogen, methyl, ethyl, methoxy, ethoxy, thiomethyl, chlorine, fluorine, bromine, iodine, cyano, amine group, morpholine, triazole, pyrazole, trifluoromethyl, difluoromethyl, ethyl formate;R2 is hydrogen, methyl, ethyl, methoxy, chlorine, fluorine, bromine, iodine, cyano, amine group, trifluoromethyl, ethyl formate;R3 is hydrogen, methyl, ethyl, methoxy, ethoxy, thiomethyl, chlorine, fluorine, bromine, cyano, amine group, morpholine, triazole, pyrazole, trifluoromethyl, difluoromethyl.The compound of the application shows excellent activity against plant pathogens, such as rice sheath blight fungus, cucumber botrytis, blueberry botrytis, strawberry botrytis, tobacco botrytis, and sclerotinia sclerotiorum.

The invention relates to a plant-source attractant for peach tree pests and application of the plant-source attractant. The plant-source attractant is selected from any one or more of beta-phellandrene, 3-methylene-6-(tert-amyl) cyclohexane-1-ene, 1-isopropyl-4-methylene cyclohexane, 4-methylene cyclohexane-1-ethyl formate, 4-oxoisophorone and 3-carene, and the plant-source attractant is selected from any one or more of beta-phellandrene, 3-methylene-6-(tert-amyl) cyclohexane-1-ene, 1-isopropyl-4-methylene cyclohexane, 4-methylene cyclohexane-1-ethyl formate, 4-oxoisophorone and 3-carene. The compound can be used for preparing a preparation for attracting peach tree pests outdoors. Compared with the prior art, the peach tree pest plant source attractant can trap and kill female adults in external environments such as a field, and the prevention and control effect is greatly improved.

The invention provides a zinc collecting agent GZ-1 and a preparation method and application of the zinc collecting agent GZ-1. The zinc collecting agent GZ-1 is composed of isobutyl xanthic acid allyl ester, isobutyl xanthic acid ethyl formate, isobutyl methyl thionocarbamate and 2-methyl-1-phenyl-2-propyl alcohol. The preparation method comprises the following steps: uniformly mixing the isobutyl xanthic acid allyl ester, the isobutyl xanthic acid ethyl formate, the isobutyl methyl thionocarbamate and the 2-methyl-1-phenyl-2-propanol according to a formula ratio, thereby obtaining the product.

The invention discloses a synthesis method of olatinib maleate. The synthesis method comprises the following steps: step 1, carrying out reaction on trans-4-hydroxycyclohexane ethyl formate under the action of a chlorination reagent to obtain a compound I; step 2, obtaining a compound II from the compound I under the action of methylamine; step 3, reacting the compound II with 4-chloro-7-toluenesulfonyl-7H-pyrrole [2, 3-D] pyrimidine under the action of alkali to obtain a compound III; 4, obtaining a compound IV from the compound III under the action of a reducing agent and a chlorination reagent; step 5, obtaining a compound V from the compound IV under the action of thiourea; step 6, obtaining VI from the compound V under the action of an oxidizing agent; step 7, obtaining a compound VII from the compound VI under the action of methylamine; step 8, preparation of the olatinib; and step 9, preparation of the maleate olatinib: the maleate olatinib is obtained from the olatinib under the action of the maleic acid. The synthesis method is simple and feasible, simple to operate and suitable for industrial production.

The invention relates to a preparation method of a key intermediate 2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate of a new generation of a xanthine oxidase inhibitor Febuxostat (Febuxostat), and particularly relates to a preparation method of the key intermediate 2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate of the xanthine oxidase inhibitor Febuxostat. According to the method, 2-(3-formyl-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate is taken as a raw material, ammonium acetate / hydroxylamine hydrochloride is taken as a nitrogen source, copper acetate / copper chloride / copper oxide is taken as a catalyst, cyanation reaction of aldehyde group is carried out, and the 2-(3-formyl-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate is obtained. And the 2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate is prepared by using the 2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate as a solvent. The purity of the 2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate prepared by the preparation method disclosed by the invention reaches 99% or above, and the yield of the 2-(3-cyano-4-isobutoxyphenyl)-4-methylthiazole-5-ethyl formate can reach 94%; the solvent used in the invention is wide in source, easy to prepare, mild in reaction condition, easy to operate, low in production cost and suitable for industrial production.

The invention relates to a tobacco flavor with glutinous rice fragrance and tea fragrance flavor and application of the tobacco flavor. The tobacco flavor is prepared from the following components: glutinous rice fragrance tea leaf essential oil, 2-carene, 2-propionyl-3, 4, 5, 6-tetrahydropyridine, 2-acetyl-3, 4, 5, 6-tetrahydropyridine, geraniol, 2-propionyl-1, 4, 5, 6-tetrahydropyridine, piperidine-2-ethyl formate and linalool. The sticky rice fragrance tea leaf essential oil and seven specific spice components are creatively combined to form the mixed spice, compared with single sticky rice fragrance tea leaf essential oil serving as spice, all the components in the mixed spice are matched and synergistic, sticky rice fragrance and tea fragrance are provided when cigarettes are smoked, the fragrance coordination of the cigarettes is obviously improved, and the flavor of the cigarettes is improved. The smoke characteristic of the cigarette is improved; after the spice is used for slow release treatment, the stability of glutinous rice fragrance and tea fragrance flavor can be maintained when cigarettes are smoked, and the flavor of the spice cannot be changed due to the change of the original proportion of the components in the slow release process, so that the sensory quality of tobacco products is comprehensively improved.

The invention discloses a stock pest fumigant and application thereof, the main active components of the fumigant are ethyl formate and mushroom alcohol, and the two components are mixed according to a specific proportion to be used for preventing and controlling stock pests such as callosobruchus maculatus, callosobruchus chinensis, rice weevil and maize weevil. Experiments prove that the blending formula of the fumigant has a remarkable synergistic effect, the defect that the mushroom alcohol is easily adsorbed by a medium is overcome while the single use concentration and the combustion risk of the ethyl formate are reduced; the efficient, safe and economical fumigation prevention and control on the storage object pests such as callosobruchus maculatus, callosobruchus chinensis, rice weevil, corn weevil and tribolium cavaleriei in the storage process of grains and agricultural products are realized. The invention provides a new solution for green prevention and control of stored insect pests.

The application belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of an intermediate 4-methyl-2-piperidinecarboxylic acid ethyl ester of argatroban. The application takes SM-1 as a starting material, realizes single bromination of an alpha position of a carbonyl group of the SM-1, and prepares a target compound through a rearrangement reaction. Compared with the prior art, the application can effectively avoid the use of a toxic cyanide in the prior art, can avoid a catalytic hydrogenation reaction, is safe in operation, can effectively reduce production cost, and is suitable for industrialized scale production.

The invention discloses a synthetic method of 3-difluoromethyl-1-methylpyrazole-4-ethyl formate, which comprises the following steps of: taking 5-difluoromethyl-1-methylpyrazole-4-ethyl formate and dimethyl carbonate as raw materials, and reacting at the temperature of between 20 and 30 DEG C to obtain 3-difluoromethyl-1-methylpyrazole-4-ethyl formate; 3-difluoromethyl-1-methylpyrazole-4-ethyl formate is synthesized under the action of a porous organic polymer catalyst immobilized with lewis acid, the porous organic polymer catalyst immobilized with lewis acid comprises a porous organic polymer, and lewis acid is immobilized on the porous organic polymer. In the synthesis method, under the action of the porous organic polymer catalyst immobilized with Lewis acid, not only can a higher reaction conversion rate be obtained at normal temperature, but also a large amount of side reactions caused by high temperature can be effectively avoided, so that the content of impurities can be remarkably reduced; the method has the advantages of simple operation, good catalyst activity, mild reaction conditions, few side reactions, fast reaction rate, high yield and the like, is suitable for industrial application, and has good market prospects.

This invention relates to the field of organic synthesis technology, specifically a method for synthesizing 2-chloro-4-(1H-pyrazol-3-yl)benzonitrile and its application, comprising the following steps: S1. Compound 1a is added to a first organic solvent under inert gas protection and reacted with vinyl isobutyl ether under the conditions of a catalyst and potassium carbonate to obtain a system containing compound 2a; S2. The pH of the system containing compound 2a obtained in step S1 is adjusted to 2-3, and after reaction, compound 1 is obtained through post-treatment; S3. Compound 1 is added to a second organic solvent, and ethyl formate and sodium ethoxide are added to react and obtain a system containing compound 4a; S4. Acetic acid is added to the system containing compound 4a obtained in step S3 for neutralization, and under inert gas protection, hydrazine hydrate is added dropwise to react and the product is obtained through post-treatment. The synthesis method provided by this invention uses readily available raw materials, has a simple processing procedure, does not require column chromatography, simplifies the operation, and facilitates industrial-scale production.

The application discloses a synthesis method of 3-difluoromethyl-1-methylpyrazole-4-methyl ethyl formate. The synthesis method is to synthesize 3-difluoromethyl-1-methylpyrazole-4-methyl ethyl formate by taking 5-difluoromethyl-1-methylpyrazole-4-methyl ethyl formate and dimethyl carbonate as raw materials and under the action of a porous organic polymer catalyst with solidified Lewis acid. The porous organic polymer catalyst with solidified Lewis acid comprises a porous organic polymer, and the porous organic polymer is solidified with Lewis acid. In the synthesis method, under the action of the porous organic polymer catalyst with solidified Lewis acid, not only a high reaction conversion rate can be obtained at normal temperature, but also a large number of side reactions caused by high temperature can be effectively avoided, thereby the impurity content can be obviously reduced, and the synthesis method has the advantages of simple operation, good catalyst activity, mild reaction condition, few side reactions, fast reaction rate, high yield and the like, is suitable for industrial application, and has a good market prospect.

The invention relates to a synthesis method of medroxyprogesterone acetate intermediate impurities. The intermediate impurity is prepared by adding (8R, 9S, 10R, 13S, 14S, 17R)-17-acetyl-10, 13-dimethyl-6-methylene-3-oxo-2, 3, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17-tetradecahydro-1H-cyclopenta [a] phenanthrene-17-acetate (B), paraformaldehyde and a specific salt catalyst into a solvent and carrying out a reaction. The high-purity medroxyprogesterone acetate intermediate impurity (8R, 9S, 10R, 13S, 14S, 17R)-17-acetyl-10, 13-dimethyl-2, 6-dimethylene-3-oxo-2, 3, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17-tetradecahydro-1H-cyclopenta [a] phenanthrene-17-ethyl formate (C) can be prepared by the synthesis method disclosed by the invention, and the impurity can be used for qualitative and quantitative determination of corresponding impurities in a medroxyprogesterone acetate intermediate and a bulk drug thereof. The characterization of the quality of the medroxyprogesterone acetate bulk drug is facilitated. The impurity synthesis route is simple to operate, the yield is high, and the purity of the obtained impurity is high.

The invention relates to the technical field of carbon nanotubes, and discloses a preparation method of a high-adsorbability carbon nanotube material, which comprises the following steps: reacting imidazole-4-ethyl formate with succinyl chloride under the catalysis of triethylamine to obtain an intermediate 1, and reacting the intermediate 1 with hydrazine hydrate to obtain an intermediate 2; and reacting the intermediate 2 with carbon disulfide to obtain the bis-imidazole diacyl thiocarbamate compound. Enabling the acidified carbon nano tube to react with 3-chloropropyl triethoxy silane, so as to obtain the chloropropyl carbon nano tube. And finally, carrying out quaternization reaction on the chloropropyl carbon nano tube and a bis-imidazole diacyl thiocarbamate compound, so as to obtain the high-adsorbability carbon nano tube material. The carbon nanotube material prepared by the method has efficient adsorbability on metal elements and organic pollutants.

The application provides a synthesis process of an ocinaplon intermediate. S1, petroleum ether, methanol and ethyl formate are mixed to obtain a mixed system, ortho-phenyltoluene and sodium methoxide are added, and reaction is carried out to obtain intermediate 1; S2, intermediate 1 is added into methanol, a palladium-carbon catalyst is added, hydrogen is introduced, and reaction is carried out to obtain intermediate 2; S3, phosphoric acid and a supported catalyst are added into intermediate 2, and reaction is carried out to obtain iminodibenzyl. The problem of low iminodibenzyl yield in the prior art is solved.

The invention discloses a thin-layer chromatography identification method and application of radix cynanchi auriculati traditional Chinese medicine formula granules and radix cynanchi auriculati traditional Chinese medicine formula granules as well as a preparation method of the radix cynanchi auriculati traditional Chinese medicine formula granules and the radix cynanchi auriculati traditional Chinese medicine formula granules, and relates to the technical field of detection methods. The method comprises the following steps: dripping a test solution on a silica gel G thin-layer plate, and developing and inspecting under thin-layer chromatography conditions; thin-layer chromatography conditions are as follows: n-hexane-ethyl formate-formic acid is used as a developing solvent; the volume ratio of the normal hexane to the ethyl formate to the formic acid is 20: 15: 1; the spreading temperature is 4-26 DEG C, and the spreading humidity is 30% rh to 60% rh; compared with a thin-layer chromatogram of the radix cynanchi auriculati traditional Chinese medicine formula granules, the radix cynanchi auriculati charcoal traditional Chinese medicine formula granules have fluorescent spots at the specific shift value of 0.421-0.458. The method can be used for rapidly and effectively identifying the radix cynanchi bungei traditional Chinese medicine formula granules or radix cynanchi bungei charcoal traditional Chinese medicine formula granules which lose the form of the decoction pieces, is simple and convenient to operate, high in precision and sensitivity and good in stability, and has a good application prospect.

This invention belongs to the field of drug synthesis technology, specifically relating to a method for synthesizing an intermediate of osimertinib. The invention uses 1-methyl-3-acetylindole as a starting material and reacts it with ethyl formate to obtain an intermediate. This intermediate, without purification, is directly cyclized with 1-(4-((2-(dimethylamino)ethyl)(methyl)amino)-2-methoxy-5-nitrophenyl)guanidine to prepare N... 1 -(2-(dimethylamino)ethyl)-5-methoxy-N 1 -methyl-N 4 -(4-(1-methyl-1H-indol-3-yl)pyrimidin-2-yl)-2-nitrobenzene-1,4-diamine. This synthetic route has mild reaction conditions, simple post-processing, and high yield, making it suitable for industrial production.

The application discloses a high-efficiency cyclization micro-reaction device for pyrazolidine ethyl formate, and relates to the technical field of reaction devices.The device comprises a bottom plate, a stirring unit, an acid-base unit, a heat exchange unit, a heat conduction unit and a heat preservation unit.The top of the bottom plate is provided with a reaction cylinder.The stirring unit is arranged on the top of the reaction cylinder.The acid-base unit is arranged on the top of the stirring unit.The heat exchange unit is arranged on one side of the reaction cylinder, and is used for recycling the temperature of the solution in the reaction cylinder.The heat conduction unit is arranged on one side of the heat exchange unit, and is used for accelerating the heat exchange speed between the solution in the reaction cylinder and the heat exchange unit.The heat preservation unit is used for storing the solution in the reaction cylinder, and can further reuse the temperature of the solution in the reaction cylinder.The device can transfer the heat of the solution in the reaction cylinder which has reacted to the raw material for the next reaction in the heat exchange box, realizes the recycling of the heat in the reaction cylinder, and saves electric energy.

The invention relates to the field of medicinal chemistry, and particularly discloses a method for synthesizing and purifying levofloxacin hydrochloride. The method comprises the following steps: taking ethyl formate (I) as a raw material, reacting with ethyl acetate under the catalysis of NaH to obtain a compound as shown in a formula (II), then carrying out a series of reactions on the obtained compound as shown in the formula (II) to obtain a compound as shown in a formula (IX), and then salifying the compound as shown in the formula (IX) through ethyl acetate hydrochloride to obtain a levofloxacin hydrochloride crude product as shown in a formula (X). Adding water into the levofloxacin hydrochloride crude product as shown in the formula (X), heating, dissolving, decolorizing with activated carbon, filtering, crystallizing filtrate, filtering and drying to obtain purified levofloxacin hydrochloride. According to the synthesis route, the traditional process is simplified, the synthesis efficiency is improved, and the production cost is reduced. By optimizing reaction conditions and purification steps, generation of harmful by-products is effectively reduced, and environmental protection requirements are met. The obtained levofloxacin hydrochloride is high in purity, meets the medicinal standard and is suitable for large-scale industrial production.

The invention discloses a preparation method of N1, N2-dimethylbenzene-1, 2-diamine, and belongs to the technical field of preparation of medical intermediates. O-phenylenediamine is used as a raw material and reacts with ethyl formate, then dimethyl sulfate is adopted for a nitrogen-methylation reaction, finally formyl is removed under the action of acid, and N1, N2-dimethylbenzene-1, 2-diamine is obtained. According to the method, all the raw materials can be conveniently purchased on the market, the process of each step of reaction is simple and convenient, no expensive catalyst is used, the yield is high, and industrial production is easy.

The application discloses a green process for synthesizing 4-methyl-2H-pyrane-2,6(3H)-dione, which comprises the following steps: (a) hydrolyzing 4,6-dimethyl-2-oxo-2H-pyrane-5-ethyl formate with liquid alkali to obtain a hydrolysis mixture, and performing negative pressure distillation on the hydrolysis mixture to recover an ethanol aqueous solution; (b) neutralizing the product of the negative pressure distillation to 7.0-7.5, centrifuging to obtain a filtrate and a residue, drying the residue to obtain anhydrous sodium salt, and performing three-stage extraction on the filtrate to obtain an aqueous phase and an organic phase; (c) performing cooling crystallization on the aqueous phase, centrifuging to obtain a precipitate and a first centrifugal filtrate, wherein the first centrifugal filtrate is used for preparing liquid alkali; performing concentration crystallization on the organic phase, recovering an extraction agent, cooling to crystallize when the concentration crystallization is performed to the point that crystals are precipitated, and centrifuging to obtain 3-methyl pentene diacid solid and a second centrifugal filtrate, wherein the second centrifugal filtrate is used for concentration crystallization; and (d) performing ring formation on the 3-methyl pentene diacid by dehydration reaction with a dehydrating agent, wherein the dehydrating agent is acetic anhydride or acetyl chloride. In this way, the discharge amount of pollutants is greatly reduced.