114 results about "Sodium ethoxide" patented technology

The invention belongs to the technical field of polyester recycling, and relates to a method for efficiently producing terephthalate by depolymerizing waste polyester through carbonic ester, which comprises the following steps: depolymerizing waste polyester, carbonic ester and a catalyst under the protection of nitrogen or inert gas and solvent-free conditions, a is more than one of zinc acetate, sodium acetate, potassium chloride, lithium chloride, potassium carbonate, sodium carbonate, ethylene glycol antimony, antimony trioxide, antimony acetate, ethylene glycol titanium and titanium dioxide, and B is sodium ethoxide. The method solves the problems of limited conversion of the waste polyester chemical recovery monomer and long production process in the prior art, obviously improves the catalytic efficiency and the depolymerization speed through the compound catalyst, simplifies the depolymerization process, reduces the energy consumption, and is beneficial to industrial application.

The invention relates to a method for producing diacetylmonoxime with high selectivity. The method comprises the following steps: by taking a catalyst, a solvent, butanone, ammonia water and a hydrogen peroxide aqueous solution as raw materials, carrying out ammoximation reaction, tert-butyl alcohol rectification, oxime-water separation and diacetylmonoxime rectification to obtain diacetylmonoxime; the catalyst is a boron-nickel-doped titanium silicalite molecular sieve, and the titanium silicalite molecular sieve, sulfydryl siloxane and ethanol are mixed to react, filtered and dried to obtain the sulfydryl titanium silicalite molecular sieve; the preparation method comprises the following steps: heating and reacting a mercapto titanium silicalite molecular sieve, allyl (cyclopentadienyl) nickel and sodium ethoxide; and finally adding (+)-IPC2B (allyl) borane, continuously reacting, and distilling to remove ethanol, thereby obtaining the product. The diacetylmonoxime prepared by the method disclosed by the invention has relatively high conversion rate and selectivity.

The invention discloses a hyperbranched water reducing agent for high-tensile wet joint UHPC (Ultra High Performance Concrete) as well as a preparation method and application of the hyperbranched water reducing agent, and belongs to the technical field of concrete admixtures. The preparation method comprises the following steps: mixing pentaerythritol and maleic anhydride, adding a catalyst p-toluenesulfonic acid, and carrying out an esterification reaction to prepare an esterification product; carrying out amidation reaction on the esterification product, diethanol amine and a catalyst sodium ethoxide to obtain a prepolymer; acrylic acid, maleic anhydride and the prepolymer are dissolved in deionized water, an initiator ammonium persulfate is added for a free radical copolymerization reaction, and a main chain polymer is obtained; carrying out phosphorylation reaction on the main chain polymer and phosphorus pentoxide to obtain a phosphorylated main chain polymer; the phosphorylated main chain polymer, methoxypolyethylene glycol and a catalyst p-toluenesulfonic acid are subjected to an etherification reaction, a hyperbranched comb-shaped polymer water reducing agent solution is obtained and then subjected to aftertreatment, and the water reducing agent is prepared. According to the hyperbranched comb-shaped polymer water reducing agent prepared by the preparation method disclosed by the invention, the problems of poor flowability and high viscosity of ultra-high performance concrete (UHPC) are solved by combining a linear side chain of a comb-shaped structure and a three-dimensional branch of hyperbranched topology.

The invention relates to a preparation method of triethylene glycol diacetate, and belongs to the technical field of organic synthesis. The method comprises the following steps: adding triethylene glycol, an acetylation reagent and a multifunctional catalyst into a reaction kettle provided with a stirrer, a thermometer and a reflux condensing tube, and stirring and heating for reaction under the protection of nitrogen; after the reaction is finished, cooling reaction liquid to room temperature, and filtering and recovering the catalyst; performing reduced pressure distillation and silica gel column purification on the filtered reaction liquid to obtain triethylene glycol diacetate; the multifunctional catalyst is prepared from mesoporous silicon dioxide microspheres, 3-mercaptopropyltrimethoxysilane, 4-vinyl benzo-18-crown ether, sodium ethoxide, absolute ethyl alcohol, an ethanol solution of tetrabutyl titanate and chlorosulfonic acid. The preparation method comprises the following steps: preparing the mesoporous silicon dioxide microspheres, 3-mercaptopropyltrimethoxysilane, 4-vinyl benzo-18-crown ether, sodium ethoxide, absolute ethyl alcohol, the ethanol solution of tetrabutyl titanate and chlorosulfonic acid; the triethylene glycol diacetate prepared by the method has high yield and high purity, and can meet industrial production and market requirements.

The invention belongs to the technical field of polyester recycling, and relates to a method for efficiently producing terephthalate by depolymerizing waste polyester with carbonate, wherein waste polyester, carbonate and catalyst are subjected to depolymerization reaction under nitrogen or inert gas protection and solvent-free conditions, the catalyst is a mixture of A and B with a mass ratio of 10 to 20:1, A is one or more of zinc acetate, sodium acetate, potassium chloride, lithium chloride, potassium carbonate, sodium carbonate, antimony glycol, antimony trioxide, antimony acetate, titanium glycol and titanium dioxide, and B is sodium ethoxide. The invention solves the problems of limited monomer conversion and long production process in chemical recycling of waste polyester in the prior art, significantly improves catalytic efficiency and depolymerization speed by compounding catalysts, simplifies the depolymerization process, reduces energy consumption, and is conducive to industrial application.

The invention discloses a preparation method of sodium-mediated lithium sulfide, which specifically comprises the following steps: preparing a sodium ethoxide solution, and dissolving a product obtained after reaction of ethanol and sodium in an organic solvent; adding lithium chloride into the solution for mixing reaction, and centrifuging to obtain a lithium ethoxide solution; introducing hydrogen sulfide gas into the solution, collecting a precipitation product, and calcining to obtain lithium sulfide. The lithium sulfide preparation conditions are mild, the reaction conditions are simple, and the product is easy to collect. The preparation raw materials provided by the invention are metal sodium, ethanol, lithium salt and hydrogen sulfide gas, so that the reaction cost is greatly reduced, commercialization feasibility is realized, and a method for recycling industrial waste gas hydrogen sulfide gas is provided and has certain environmental protection value.

A liquid treatment composition for remediating and removing mercaptans, H2S and other sulfur based contaminants from contaminated hydrocarbon liquids, the treatment composition consisting essentially of a carrier solvent and at least one alkoxide compound. The liquid treatment composition may contain no terpene. Further, the liquid treatment composition may include water. The at least one alkoxide compound includes at least one of sodium methoxide and sodium ethoxide.

The present invention relates to an iron ore reverse flotation inhibitor and a preparation method thereof. In the first step, a mixture of the following components by weight is reacted at 40°C to 50°C for 1 to 6 hours to obtain an auxiliary agent (1): 100 parts of corn starch, mung bean starch, or potato starch, 0.5 to 4.0 parts of sodium hydroxide or sodium ethoxide, 5 to 15 parts of methyl chloroacetate, and 5 to 15 parts of hydroxylamine hydrochloride or hydroxylamine sulfate. In the second step, a mixture of the following components by weight is reacted at 20°C to 50°C for 1 to 3 hours to obtain a finished inhibitor: 100 parts of the auxiliary agent (1) obtained in the first step and 1 to 12 parts of sodium hypochlorite. The inhibitor has strong inhibitory ability, selectivity, and low-temperature adaptability and can be used for room-temperature flotation.

The present invention relates to a method for producing a low-temperature reverse flotation inhibitor for iron ore. The method comprises the following steps: first, reacting a mixture of the following components by weight at 50°C to 60°C for 6h to 8h to obtain an auxiliary agent (1): 100 parts of corn starch and cassava starch, 0.1 to 0.3 parts of hydrogen peroxide, 0.05 to 0.15 parts of ferrous sulfate, and 3 to 5 parts of acrylonitrile; second, reacting a mixture of the following components by weight at 45°C to 55°C for 3 to 4h to obtain an auxiliary agent (2): 100 parts of the auxiliary agent (1) obtained in the first step, 3 to 8 parts of propylene oxide, and 0.1 to 0.8 parts of sodium ethoxide; and third, reacting a mixture of the following components by weight at 40°C to 50°C for 2 to 3h to obtain a finished inhibitor: 100 parts of the auxiliary agent (2) obtained in the second step and 1 to 3 parts of ammonium persulfate. The inhibitor has strong inhibitory ability, selectivity, and low-temperature adaptability and can be used for room-temperature flotation.

The present invention relates to a method for preparing (Z)-3-(2-(5-bromo-1H-indol-3-yl)-2-cyanovinyl)-4-methoxybenzonitrile, which comprises reacting tert-butyl 5-bromo-3-(cyanomethyl)-1H-indole-1-carboxylate, 3-formyl-4-methoxybenzonitrile, and sodium ethoxide solution.

The present application relates to a regenerated blended cotton yarn, which is treated with a surface treatment agent, and the surface treatment agent components are sodium dodecyl sulfonate, mica powder, p-methoxy salicylaldehyde, 3,4-dimethoxyphenylacetonitrile, sodium ethoxide, silicone oil emulsion, anhydrous ethanol and water; a production process of regenerated blended cotton yarn includes the preparation of a surface treatment agent and the surface treatment of the regenerated blended cotton yarn. The present application has the following advantages and effects: sodium dodecyl sulfonate and mica powder both have a conductive effect, which can cause static electricity to leak in time; p-methoxy salicylaldehyde can be hydrogen bonded to the hydroxyl groups on the cotton fibers of the cotton yarn, and the oxygen atom in the methoxy group of methoxy salicylaldehyde will produce a conjugated effect with the benzene ring; further, p-methoxy salicylaldehyde and 3,4-dimethoxyphenylacetonitrile react to form a chemical bond, extend the conjugated chain length, and improve conductivity and antistatic properties; silicone oil emulsion has antistatic and water repellency, and maintains the antistatic properties of the regenerated blended cotton yarn after washing.

The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of substituted phenylene aromatic diester and application of the substituted phenylene aromatic diester in catalyst preparation. The preparation method comprises the following steps: firstly, enabling 2-hydroxy-3-methyl benzaldehyde to react with m-chloroperoxybenzoic acid and sodium ethoxide to generate 3-methyl catechol; then, triisobutyl aluminum is used as a catalyst, 3-methylcatechol and isobutene are subjected to a reaction, and 5-tert-butyl-3-methylcatechol is generated; finally, the 5-tert-butyl-3-methyl catechol reacts with triethylamine and benzoyl chloride, and the 5-tert-butyl-3-methyl catechol is obtained. According to the novel preparation method of the substituted phenylene aromatic diester, by selecting the specific alkaline reagent and the catalyst, the dependence of a traditional reduction method on a metal reagent is avoided, the yield and the purity of the substituted phenylene aromatic diester are greatly improved, the reaction condition is mild, the cost is low, and the method is suitable for large-scale preparation.

The invention relates to the field of pesticide synthesis, in particular to a synthesis method of ethonicotinic acid. 5-ethyl pyridine-2. 3-dicarboxylic acid diethyl ester and 2-amino-2. 3-dimethyl butyramide are used as raw materials and react in a sodium ethoxide ethanol solution at the temperature of 50-70 DEG C, hydrogen chloride gas is introduced into a system for acidification after the reaction is completed, and imazethapyr and a by-product sodium chloride are obtained. The hydrogen chloride gas is directly introduced in the acidification process, and the acidification process is free of hydration, so that on one hand, no direct wastewater is generated, the generation of wastewater with high salt content and high organic matter content is avoided, the treatment cost is reduced, on the other hand, the byproduct sodium chloride is firstly removed from the system by controlling the ethanol amount of the system, and then concentration and crystallization are performed; the high-purity imazethapyr of which the purity is greater than 99% is obtained by utilizing the solubility of the solvent ethanol to impurities, and the quality of both byproducts and main products is at a higher level in the industry.

The invention discloses a preparation method of 1-amino-2-cyano-1-cyclopentene, which comprises the following steps: 1, preparing a mixed solution, namely mixing a first organic solvent with super alkali in a protective gas atmosphere, heating by adopting a nano infrared energy-saving electric heating coil, stirring, uniformly mixing and dissolving to obtain the mixed solution; the super base is selected from one of potassium tert-butoxide, sodium tert-butoxide, sodium ethoxide, sodium methoxide and sodium hydroxide; 2, cyclization reaction: dropwise adding adiponitrile into the mixed solution, and continuously carrying out infrared heat preservation reaction for 3-8 hours to obtain a reaction solution of 1-amino-2-cyano-1-cyclopentene; 3, cooling crystallization and filtration: cooling the reaction liquid to-10-5 DEG C, standing for crystallization, and carrying out pressure filtration in a protective gas atmosphere to obtain an ACCP crude product and a filtrate; and 4, recrystallizing and refining to obtain a pure product. The method is mild in reaction condition, low in energy consumption, good in product yield and high in product purity, solves the problems of high solvent toxicity, low yield and high environmental protection pressure in the prior art, and is suitable for production of medicine and pesticide intermediates.

This invention relates to a method for preparing a graphene-based coated iron catalyst for the deep removal of trace amounts of acetylene and ethylene impurities from electronic-grade hydrogen chloride, belonging to the field of catalyst technology. The method involves dispersing phenolic resin and graphene quantum dots in toluene, adding allyltrimethylammonium bromide, ferrocene methylamine, and sodium ethoxide, heating and stirring the reaction, and adjusting the pH with acetic acid. Citric acid and ferric acetylacetone are then added, and the mixture is stirred. Sodium borohydride is added in two stages, and the reaction is continued with stirring to obtain a gel precursor. The gel precursor is then ultrasonically dispersed, dried, and subjected to staged heating in a nitrogen-hydrogen atmosphere to obtain the resin-based coated iron catalyst. The catalyst prepared by this invention can effectively remove trace amounts of acetylene and ethylene impurities from electronic-grade hydrogen chloride, improving the purity of electronic-grade hydrogen chloride.

The invention discloses a preparation method of ethyl p-methoxycinnamate, and belongs to the technical field of chemical synthesis. The preparation method of the ethyl p-methoxycinnamate comprises the following steps: mixing ethyl acetate and an ethanol solution of sodium ethoxide, dropwise adding p-methoxybenzaldehyde at 5-10 DEG C, and reacting at 30-50 DEG C to obtain the ethyl p-methoxycinnamate. The yield of the ethyl p-methoxycinnamate prepared by the preparation method provided by the invention can reach 90% or above, and the purity can reach 99.0% or above.

The invention relates to the field of chemical synthesis, in particular to a synthetic method and application of vanillin and derivatives thereof. The synthesis method comprises the following synthesis steps: S1, bromination: reacting p-hydroxybenzaldehyde with a brominating agent to obtain a mixture of 3-bromo-4-hydroxybenzaldehyde and 3, 5-dibromo-4-hydroxybenzaldehyde; s2, separation and purification: taking the mixture of the 3-bromo-4-hydroxybenzaldehyde and the 3, 5-dibromo-4-hydroxybenzaldehyde, sequentially carrying out recrystallization and melt crystallization, and separating the 3-bromo-4-hydroxybenzaldehyde and the 3, 5-dibromo-4-hydroxybenzaldehyde; s3, etherification: taking 3-bromo-4-hydroxybenzaldehyde to react with sodium methoxide or sodium ethoxide, so as to obtain an etherified product. According to the method disclosed by the invention, high-purity 3-bromo-4-hydroxybenzaldehyde and 3, 5-dibromo-4-hydroxybenzaldehyde are obtained through recrystallization coupled with melt crystallization separation; the whole process is free of material loss, safe and environment-friendly.

The invention relates to the technical field of pharmaceutical engineering, in particular to a fluorouracil production process which specifically comprises the following condensation reaction steps: S1, adding a base catalyst into dichloromethane, and dropwise adding ethyl formate and ethyl fluoroacetate to obtain a mixture, the mass of the dichloromethane is 3-7 times that of the ethyl fluoroacetate, and the molar equivalence ratio of the added base catalyst to the ethyl formate to the ethyl fluoroacetate is (2.5-3.5): 2.5: 1; s2, controlling the temperature of the mixture obtained in S1 to 30-40 DEG C, and continuously stirring to react for 0.5-2 hours to obtain an intermediate state substance; according to the production process of the fluorouracil, provided by the invention, the production cost during mass production can be remarkably reduced, and meanwhile, the quality and the stability of the fluorouracil product are ensured.

The present invention relates to an antibacterial mefenamic acid silver complex, and its preparation method and application. An antibacterial mefenamic acid silver complex, whose pharmaceutically acceptable compound structure is as follows:. The preparation method of the mefenamic acid silver complex comprises the following steps: first, reacting the ligand mefenamic acid with sodium ethoxide to generate mefenamic acid sodium salt; then, adding the obtained mefenamic acid sodium salt dropwise to a silver nitrate solution; and slowly volatilizing for 3 days to obtain colorless crystals, namely the mefenamic acid silver complex. The mefenamic acid silver complex has an excellent inhibitory effect on common bacteria, and is superior to silver nitrate or mefenamic acid in in vitro tests, and has the potential to replace or supplement existing antibacterial agents on the market. The antibacterial mefenamic acid silver complex or its salt is used as an active component in the preparation of antibacterial agents.

The invention relates to a clean production process for co-producing diacetylmonoxime and acetaldehyde oxime. The method comprises the following steps: adding a modified catalyst, solvent water and butanone into a reaction kettle, starting to stir and heat under the protection of nitrogen, slowly introducing ammonia gas, then slowly adding a hydrogen peroxide aqueous solution, and after the reaction is finished, carrying out centrifugal separation to obtain diacetylmonoxime; the preparation method comprises the following steps: adding hydroxylamine hydrochloride and water into a reaction kettle, stirring to dissolve the hydroxylamine hydrochloride and the water, dropwise adding acetaldehyde under cooling of an ice-water bath, and reacting; dropwise adding alkali liquor, and stirring to obtain an acetaldehyde oxime water solution; the method comprises the following steps: extracting an acetaldoxime aqueous solution with dichloromethane, drying an extract liquid with anhydrous sodium sulfate, fractionating at normal pressure to obtain most of a solvent, fractionating at reduced pressure, and collecting fractions to obtain anhydrous acetaldoxime; the modified catalyst disclosed by the invention is obtained by reacting a TS-1 molecular sieve, mercapto siloxane, (E)-1-allyl potassium trifluoroborate, allyl trimethyl stannane, methylbenzene and sodium ethoxide; the diacetylmonoxime and acetaldehyde oxime prepared by the invention have higher purity.

The application discloses a preparation method of 2-cyano-3-hydroxy-2-buten-(4-trifluoromethyl-phenyl)amide, which comprises the following steps: reacting a compound of formula (II) with acetyl chloride or acetic anhydride under the action of a base; wherein the base comprises sodium ethoxide and / or sodium methoxide. In the application, sodium hydride with a relatively high risk coefficient is replaced by sodium alcoholate, the operation difficulty is reduced, the yield is improved compared with sodium hydride, and the application is more suitable for industrial production.

The application belongs to the technical field of organic synthesis, and particularly relates to a preparation method of substituted phenylene aromatic diester and application thereof in preparation of a catalyst. The preparation method comprises the following steps: first, 2-hydroxy-3-methylbenzaldehyde is reacted with meta-chloro peroxybenzoic acid and sodium ethoxide to generate 3-methyl catechol; then, 3-methyl catechol is reacted with isobutene by taking triisobutyl aluminum as a catalyst to generate 5-tert-butyl-3-methyl catechol; finally, 5-tert-butyl-3-methyl catechol is reacted with triethylamine and benzoyl chloride, and the substituted phenylene aromatic diester is obtained. The application provides a novel preparation method of the substituted phenylene aromatic diester, the dependence on metal reagents in a traditional reduction method is avoided by selecting specific alkaline reagents and catalysts, the yield and purity of the substituted phenylene aromatic diester are greatly improved, the reaction condition is mild, the cost is low, and the method is suitable for large-scale preparation.

The invention provides a preparation method of carbon fiber reinforced zirconium carbide ceramic, and belongs to the technical field of ceramic. The preparation method comprises the steps of zirconium carbide pretreatment, vinylated carbon fiber preparation, zirconium carbide-carbon fiber preparation, zirconium carbide-carbon fiber modification, material mixing and sintering. The zirconium carbide-carbon fiber modification step comprises the following steps: putting zirconium carbide-carbon fibers into N, N-dimethylformamide, uniformly stirring, adding aminated carbon fibers and sodium ethoxide, carrying out a stirring reaction at 32-36 DEG C for 10-14 h, after stirring is finished, carrying out filtering and washing, carrying out freeze drying, and after drying is finished, naturally recovering to room temperature to obtain the zirconium carbide-carbon fiber composite material. The modified zirconium carbide-carbon fiber is prepared; the ceramic product prepared by the method disclosed by the invention is high in yield, good in mechanical property and excellent in corrosion resistance.

The present invention relates to a process for the preparation of (Z)-3-(2-(5-bromo-1H-indol-3-yl)-2-cyanovinyl)-4-methoxybenzonitrile, which comprises the reaction of tert-butyl 5-bromo-3-(cyanomethyl)-1H-indol-1-formate, 3-formyl-4-methoxybenzonitrile, and a sodium ethoxide solution. The invention also relates to a process for the preparation of (Z)-3-(2-(5-bromo-1H-indol-3-yl)-2-cyanovinyl)-4-methoxybenzonitrile.

This invention provides a method for synthesizing the compound DDAO-Sulfate, belonging to the field of chemical synthesis technology. The method includes the following steps: mixing DDAO and sodium ethoxide with anhydrous dimethylformamide to obtain a mixed solution; adding pyridine sulfur trioxide to the mixed solution and heating and stirring the reaction under light-protected conditions; subsequently concentrating under vacuum to obtain a residue; and purifying the residue by column chromatography using an eluent to obtain the final product. This synthetic method effectively improves the yield while selecting and optimizing the reactants, avoiding the use of easily deteriorated reagents and interference caused by the introduction of irrelevant substances, thus providing an efficient pathway for the preparation of fluorescent detection probes for sulfatase.

The invention relates to a preparation method of a skeleton embedded compact asphalt mixture, and belongs to the technical field of asphalt mixture preparation. Putting the preheated coarse aggregate and fine aggregate into stirring equipment, carrying out dry mixing, then adding the modified asphalt, carrying out wet mixing, finally adding the modified filler, and continuously carrying out wet mixing, so as to obtain an asphalt mixture; loading the asphalt mixture into a test mold, adopting a double-sided static pressure molding process, performing static pressure, cooling and demolding to obtain a skeleton-embedded compact asphalt mixture; the modified filler is prepared from limestone mineral powder, gamma-methacryloxy propyl trimethoxy silane, 8-anilino-1-naphthalene sulfonic acid magnesium salt, absolute ethyl alcohol and sodium perethoxide; the Marshall stability, the low-temperature bending strain and the freeze-thaw splitting strength ratio of the prepared asphalt mixture are remarkably improved, and the asphalt mixture can effectively resist high-temperature rutting, low-temperature cracking and water damage.

The present application relates to the technical field of hazardous chemical treatment, and specifically discloses a method for destroying waste sodium and potassium, which includes preparing a waste sodium and potassium destruction solution using anhydrous ethanol, long-chain alkyl silicone oil and polyether-modified silicone oil, and pouring the waste sodium and potassium into the destruction solution for destruction, which can not only safely destroy the waste sodium and potassium, but also add a modifier polyether-modified silicone oil to ethanol, the role of the modifier is to increase the ignition point and boiling point of ethanol, reduce the risk of high-temperature combustion, prevent ethanol from escaping, and ensure that there is no high temperature, open flame and slow reaction rate during the reaction process. Ethanol and sodium and potassium react to produce sodium ethanolate and hydrogen. The elemental sodium and potassium are heavier than the modifier and sink. In the process of contacting with ethanol, the generated hydrogen escapes through the modifier, preventing the risk of hydrogen accumulation and explosion caused by high temperature. This method does not require the establishment of an equipment system, saving investment costs.

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 invention discloses a preparation method of (S)-(2-oxotetrahydrofuran-3-yl)-carbamate, which is characterized by comprising the following steps: S1, taking L-homoserine and dimethyl carbonate as reaction raw materials, and reacting in a methanol solvent under the action of a concerted catalytic system consisting of sodium ethoxide and zinc acetate to obtain a compound (1); s2, the compound (1) is subjected to a cyclization reaction under the acidic condition, and (S)-(2-oxotetrahydrofuran-3-yl)-carbamate is obtained. The preparation method provided by the invention does not use a large amount of acid-binding agent, has high use efficiency and low catalyst consumption, selects the amino protective agent with low price, reduces the cost and three wastes, and is beneficial to large-scale production.

The invention belongs to the technical field of synthesis of diboron compounds, and particularly relates to a synthesis method of a 1, 3-diboron compound. Comprising the following steps: by taking an olefin compound, bis (pinacol) diborate and iodomethylene borate as raw materials, carrying out olefin carbon boronation reaction in a reaction system consisting of a Cu-based catalyst, sodium ethoxide and a solvent under a protective atmosphere to obtain the 1, 3-diboron compound. The invention provides a copper-catalyzed olefin boron alkylation strategy, iodomethylene borate is used as an electrophilic reagent, a series of racemic 1, 3-diboron compounds are constructed at excellent yield through a Cu-catalyzed olefin carbon boronation reaction, and an effective modularized synthesis method of the 1, 3-diboron compounds is realized. The reaction has the characteristics of mild reaction conditions, wide raw material sources, simple reaction process and high yield.