375 results about "Sulfoxide" patented technology

The invention discloses a preparation method for selectively oxidizing thioether into sulfoxide through photo-initiation, and belongs to the field of synthesis of medical compounds. The preparation method comprises the following steps that in the air atmosphere, a thioether compound is dissolved in an acetonitrile-water mixed solvent, inorganic metal salt catalysts such as ferric chloride and copper sulfate are added, the mixture reacts for 8-48 h at the temperature of 0-45 DEG C under illumination with the wavelength of 295-405 nm, selective oxidation is carried out, and the sulfoxide product is obtained, and the molar ratio of thioether to the catalysts is 5: 1. The method overcomes the problems of excessive oxidation risk, complicated operation, environmental pollution and the like caused by dependence of a noble metal catalyst and use of a strong oxidant in the existing thioether oxidation method, has the advantages of high catalytic efficiency, high yield and excellent selectivity, can greatly reduce the production cost, is suitable for later industrial synthesis and amplification, and has wide application prospects. The method has the advantages of no expensive metal catalyst or oxidant, simple preparation process, high efficiency, environmental protection, safety and cost saving.

The invention relates to the technical field of biochemical engineering, in particular to a method for preparing chiral alpha-trifluoromethyl alcohol by using imine reductase AtRedAm, trifluoromethyl ketone is reduced into corresponding chiral trifluoromethyl alcohol at an excellent conversion rate by using the imine reductase AtRedAm, and enantioselectivity is high. The reaction depends on an NADPH (Nicotinamide Adenine Dinucleotide Phosphate) coenzyme circulation system, 10% dimethyl sulfoxide is used as a reaction cosolvent, the reaction is carried out in a 100mM (pH = 7.5) phosphate buffer solution for 16 hours, the highest molar conversion rate reaches 99%, and the highest optical purity reaches 95%.

The invention belongs to the technical field of soil organic matter improvers, and discloses a soil organic matter improver based on a compound microbial agent and a preparation method thereof, and the soil organic matter improver comprises the following components: a compound enzyme, a modified chitosan microsphere complex, a modified polyelectrolyte, an inhibitor L-methionine sulfoximine, a substrate, an auxiliary factor and the compound microbial agent. A compound enzyme system is used as a core, soil ammonium ions are circularly and efficiently assimilated through glutamine synthetase / glutamate synthetase, and the soil ammonium ions are converted into organic nitrogen; and energy guarantee is provided by virtue of polyphosphate kinase. The modified chitosan microsphere complex is used for protecting and slowly releasing enzyme and a substrate, and controlled release of the inhibitor L-methionine sulfoximine is realized through the modified polyelectrolyte, so that carbon-nitrogen balance of soil is regulated and controlled. The system has a synergistic effect with a compound microbial agent, the problem of soil organic matter reduction caused by excessive nitrogen application is effectively solved, meanwhile, the crop root biomass is remarkably increased, and the soil organic matter content is increased.

The invention provides a lithium battery diaphragm and a preparation method thereof, and the preparation method comprises the following steps: carrying out a reaction on melamine and terephthalaldehyde in dimethyl sulfoxide to obtain SNW-1COF; the preparation method comprises the following steps: enabling SNW-1COF to react with allyl-1, 3-sultone in acetonitrile, so as to obtain allyl SCOF; the polyarylether benzimidazole, the 2-sulfydryl-5-fluorobenzimidazole, triethylamine and allyl SCOF are subjected to a reaction in a third solvent, and a membrane casting solution is obtained; and applying the membrane casting solution to a base material, and removing the solvent in the membrane casting solution to obtain the lithium battery diaphragm. According to the invention, the OPBI matrix and the propenyl SCOF react to form a covalent cross-linked network, so that the mechanical properties of the diaphragm in the aspects of thermal shrinkage rate, tensile strength, puncture strength and the like and the electrical properties in the aspects of wettability and ionic conductivity are improved.

The invention relates to preparation and application of a substituted alkyl sulfide (sulfoxide) arylamine derivative. Specifically, the invention relates to a compound as shown in a formula (I), or an isotope labeled compound thereof, or an optical isomer, a geometric isomer, a tautomer or an isomer mixture thereof, or a pharmaceutically acceptable salt thereof, and an application of the compound in preparation of an acaricide for preventing and controlling pest mites, wherein the compound is used as a substituted alkyl sulfide (sulfoxide)-based arylamine derivative. The compound can achieve a better pest mite control effect at a lower dosage.

The invention belongs to the technical field of thermoelectric materials and functional polymer materials, and particularly relates to thermoelectric hydrogel based on synergistic enhancement of zwitterions and a polar solvent as well as a method and application of the thermoelectric hydrogel. The thermoelectric hydrogel is obtained through the steps that a precursor solution is subjected to a polymerization reaction to form a gel matrix, then the gel matrix is soaked in a soaking solution, potassium ferricyanide / potassium ferrocyanide redox couple is introduced, and the thermoelectric hydrogel is obtained, and the precursor solution is prepared from acrylamide, N-isopropylacrylamide, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide and N, N-dimethylformamide. The photoinitiator is prepared by mixing N, N-dimethylformamide, 1-ethyl-3-methylimidazolium tetrafluoroborate, a zwitterionic monomer [2-(methylacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide, a cross-linking agent N, N '-methylene bisacrylamide, a photoinitiator and deionized water. The thermoelectric hydrogel prepared by the invention has high mechanical strength, high ductility and high Seebeck coefficient, and has better temperature resistance.

The invention belongs to the technical field of organic synthesis, and particularly relates to a pyroxasulfone preparation method which specifically comprises the following steps: dissolving 3-(5-difluoromethoxy-1-methyl-3-trifluoromethyl-1H-pyrazol-4-ylmethylthio)-5, 5-dimethyl-2-isoxazoline serving as a raw material with a solvent, then adding a boron compound, finally dropwise adding hydrogen peroxide, and reacting at room temperature to obtain the pyroxasulfone. Reacting for several hours to obtain pyroxasulfone; the adopted boron compound is cheap and easy to obtain, so that the use of a transition metal catalyst is avoided, and the raw material cost is reduced; organic acid reagents with heavy odor are not used, waste water and solid waste are less, and the method has great advantages in the aspect of environmental protection; the method is simple to operate, free of complex treatment steps and suitable for industrial production, and when the boron compound is selected from sodium metaborate, sodium perborate or a mixture of borax and sodium metaborate, the yield and purity of the process are higher, and sulfoxide impurities are fewer.

The invention provides a hydrated eutectic electrolyte as well as a preparation method and application thereof. The electrolyte comprises water-soluble zinc salt, deionized water and a deep eutectic solution, the deep eutectic solution is formed by mixing zinc perchlorate and a polar deep eutectic solvent and performing deep eutectic crystallization. The electrolyte has the characteristics of low water activity, low freezing point and efficient induction of uniform deposition of zinc, can be compatible with an iodine-loaded positive electrode and can inhibit dissolution of iodine, and the characteristics are beneficial to inhibition of hydrogen evolution reaction, polyiodine shuttling and other side reactions in the battery circulation process, promote uniform deposition of zinc, protect the integrity of an iodine electrode, and improve the electrochemical performance of the battery. The stable operation of the zinc-iodine battery is ensured; the electrolyte is a zinc sulfate solution containing a ZnClO4 / dimethyl sulfoxide deep eutectic solvent, the solution is combined with free water to form a eutectic structure, the eutectic structure participates in construction of a Zn < 2 + > ion solvation shell, extra intramolecular hydrogen bonds are introduced for the electrolyte, meanwhile, hydrogen bonds among water molecules are weakened, so that the internal energy of the electrolyte is enhanced, the freezing point is reduced, and the flowability is improved.

The invention discloses a dual-band acridine formic acid anthracene methyl ester photocatalyst as well as a preparation method and application thereof, and belongs to the field of heterocyclic compounds. The invention designs and synthesizes a novel acridine formic acid anthracene methyl ester photocatalyst, which has good compatibility in two wavebands of 365 nm and 405 nm, can realize photocatalysis of disulfide compounds and aryl formyl peroxide compounds, and provides a new thought for preparation of sulfoxide compounds with asymmetric structures; the reaction conditions are mild, the reaction time is short, the photocatalyst can be recycled, the circulation loss is low, the circulation efficiency is high, the production efficiency is greatly improved, and the production period and cost are reduced; the product is free of transition metal residues and high in yield.

The invention provides a preparation method of (S)-oxetane-2-methylamine. The preparation method of (S)-oxetane-2-methylamine comprises the following steps: (1) carrying out ring closing reaction on a compound A under an alkaline condition to obtain a compound B; (2) reacting the compound B with dibenzylamine to obtain a compound C; (3) reacting the compound C with a reducing agent to obtain a compound D; (4) reacting the compound D with paratoluensulfonyl chloride to obtain a compound E; (5) reacting the compound E with alkali to obtain a compound F; and (6) carrying out a reaction on the compound F and palladium on carbon to obtain the (S)-oxetane-2-methylamine. According to the preparation method provided by the invention, ring expansion reaction using trimethylsulfoxide iodide in the prior art is avoided, the problem that residual sulfur elements cause poisoning of a palladium-carbon catalyst is solved, meanwhile, sodium azide is also avoided, and the preparation method is safe and reliable in process, high in chiral purity and yield and suitable for industrial large-scale production.

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

The invention discloses a folic acid modified active oxygen response type sodium alginate nano-carrier and application thereof, and the preparation method comprises the following steps: firstly synthesizing-Se-Se-FA: stirring dicyclohexylcarbodiimide, 4-dimethylaminopyridine, dimethyl sulfoxide / pyridine, a double-selenium fragment and folic acid at room temperature for 18-22 hours in an argon environment; and carrying out acetone precipitation, centrifugation, washing, rotary evaporation concentration and freeze-drying. The preparation method comprises the following steps: preparing an ALG-Se-FA carrier, stirring sodium alginate, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and hydroxysuccinimide in a 2-morpholinoethanesulfonic acid buffer solution, adding DMSO, dissolving a double-selenium fragment and a-Se-Se-FA fragment in DMSO and deionized water, adding the dissolved double-selenium fragment and-Se-Se-FA fragment into a system, stirring, dialyzing, and freeze-drying to obtain the product. According to the carrier, a double-selenium bond ROS response unit and folic acid targeting molecules are introduced through covalent bonds, astaxanthin can be efficiently entrapped and protected, and after the carrier is stable in gastrointestinal environment and reaches a colitis disease part, high ROS level can be responded, and intelligent drug slow release is achieved through folic acid receptor targeting.

The invention discloses an ergothioneine-producing recombinant engineering bacterium as well as a construction method and application thereof, and belongs to the technical field of gene recombination fermentation. The method comprises the following steps: by taking escherichia coli as a starting bacterium, carrying out recombinant expression on a histidine trimethyl inner salt cysteine sulfoxide synthetase egt1 gene, an L-histidine methyltransferase egtD gene, a histidine trimethyl inner salt cysteine sulfoxide lyase egt2 gene, a methionine adenosine transferase metK gene, an adenylate kinase adK gene and an adenine phosphoribose transferase apt gene; on this basis, supply of precursor substances including histidine, cysteine and methionine is further improved through metabolic transformation, the yield of the finally obtained recombinant engineering bacterium for producing ergothioneine reaches 2.54 g / L after 48 h of shake-flask culture, the yield of a 5L fermentation tank reaches 18 g / L after further enlarged culture, the yield of ergothioneine is guaranteed while energy consumption and cost are reduced, and the method is suitable for industrial production. The method is suitable for practical popularization.

The present invention relates to a method of preparing a heterogeneous linear carbonate, the method including performing a transesterification reaction of dimethyl carbonate (DMC) and ethanol (EtOH) in the presence of a catalyst, wherein the catalyst is one or more selected from the group consisting of lithium methoxide (LME), lithium ethoxide (LEE), sodium methoxide (SME), sodium hydroxide (NaOH), and a mixture thereof, and the catalyst is input in a state of being dissolved in a sulfoxide-based solvent.

The invention discloses a method for synthesizing a sulfur-containing compound by using an amino sulfur trifluoride compound, which comprises the following two steps: S1, by taking the amino sulfur trifluoride compound and a compound A as reactants, stirring and reacting for 8-15 minutes or 10-15 hours at normal temperature in an organic solvent under an alkaline condition; the compound A is any one of an amide compound or a sulfanilamide compound, or water; and S2, adding a nucleophilic reagent into the solution after the reaction in the step S1, stirring at normal temperature to react for 8-15 minutes or 5-8 hours, and then purifying through a rapid chromatography to obtain a final product, namely, all-heteroatom substituted thioimine or all-heteroatom substituted sulfoxide, the nucleophilic reagent is an alcohol or an amine. According to the method disclosed by the invention, the amido sulfur trifluoride compound is used for synthesizing the asymmetric full heteroatom substituted thioimine and sulfoxide compound for the first time, the reaction steps are simple, the reaction conditions are mild, and expensive reagents are not needed.

Disclosed is a method for preparing oxetan-2-ylmethanamine, which belongs to the field of organic synthesis. [2-(1-ethoxyethoxy)methyl]propylene oxide is used as an initial raw material, and reacted in the presence of potassium tert-butoxide and trimethylsulfoxonium iodide; the resulting product is reacted with a sulfonyl compound and triethylamine; the resulting product is reacted with a compound of phthalimide; the resulting product is reacted with an amino group-containing compound, to obtain oxetan-2-ylmethanamine. The method according to the disclosure allows for an overall yield of not less than 30% in scale-up production (kilogram level), which is higher. Moreover, compared with the traditional method for preparing oxetan-2-ylmethanamine, a palladium-carbon catalytic hydrogenation step is not required, and dangerous chemical-sodium azide is not required in the method according to the disclosure. Thus, the method has high safety, low production cost, simple operations, and thereby is suitable for industrial production.

The invention relates to a ZnAl-LDH-based material as well as a preparation method and application thereof in sludge treatment. The ZnAl-LDH-based material is prepared from a divalent metal salt solution and a trivalent metal salt solution through a coprecipitation method, divalent metal comprises Zn and Cu, and trivalent metal is Al; the molar weight ratio of the divalent metal to the trivalent metal is (1-3): 1, and the ratio of the molar weight of Cu to the total molar weight of the divalent metal is (0-0.5): 1. The ZnAl-LDH-based material is used for promoting the organic sulfide in the sludge to be converted into sulfoxide sulfur and sulfone sulfur. Compared with the prior art, a series of ZnAl-LDH-based materials with proper specific surface areas and pore volume structures are prepared, and low-valence organic sulfides in municipal sludge can be promoted to be directionally converted into sulfoxide sulfur and sulfone sulfur; the method has a wide application prospect in the field of improving the high-added-value utilization of organic sulfide-containing wastes such as municipal sludge.

The present invention provides a thiadiazole compound containing a hindered phenol group, a preparation method thereof and its use in the field of lubricating oil additives. The preparation method of the thiadiazole compound containing a hindered phenol group comprises the following steps: mixing a carboxylic acid compound containing a hindered phenol group with thionyl chloride, removing impurities under reduced pressure to obtain an acyl chloride compound containing hindered phenol; stirring and mixing 2-mercapto-5-amino-1,3,4-thiadiazole with a halogenated hydrocarbon compound, filtering, washing and drying to obtain a 2-mercapto-5-amino-1,3,4-thiadiazole derivative; adding a hindered phenol acyl chloride compound, 2-mercapto-5-amino-1,3,4-thiadiazole derivative and an alkaline additive to an organic solvent, washing, drying and purifying to obtain a thiadiazole compound containing a hindered phenol group. The thiadiazole compound containing a hindered phenol group is an antioxidant, extreme pressure and anti-wear additive, which can be applied to synthetic ester lubricants and has a good antioxidant, extreme pressure and anti-wear effect.

The application provides a catalyst for synthesizing polyimide, and a structural formula of the catalyst is shown as formula (I): wherein, Ar 1 , Ar 2 are independently selected from substituted or unsubstituted aryl or substituted or unsubstituted heterocyclic aryl, R1 is oxygen, sulfur, sulfone group, sulfoxide group, carbonyl group, secondary amine group, alkylene group, alkenylene group, alkinylene group, alicyclic group, heterocyclic aryl group, fused ring aryl group or single bond. The catalyst has high reactivity, and a small amount of the catalyst is used in the synthesis of polyimide, so that the film forming property of the polyimide is not affected. The application further provides a preparation method and application of the catalyst for synthesizing polyimide.

The invention relates to a process for preparing 1,2′-benzisothiazoline-3-one according to formula (I), comprising the following steps: (a) reacting a 2-halogenbenzonitrile compound of general formula (II) with a reaction mixture, containing: (i) alkaline sulphide and / or alkaline hydrogen sulphide and (ii) an alkyl halide compound, represented by general formula (III): R1X (III) for producing an intermediate product of general formula (IV), and (b) reacting the intermediate product of general formula (V) obtained in step (a) with a halogenating agent or an oxidant and subsequent reaction of the 2-(alkylsulfoxy)benzonitrile with an acid to form 1,2-benzisothiazoline-3-one as well as a halide compound of general formula (V) R1X (V).

The invention discloses a production device for producing dimethyl sulfoxide by using a micro-channel reactor and application of the production device, and belongs to the technical field of dimethyl sulfoxide production. The production device for producing dimethyl sulfoxide by using the micro-channel reactor comprises a refined thioether buffer tank and a hydrogen peroxide buffer tank, the refined thioether buffer tank is connected with a sulfoxide reaction device through a pipeline, a rectified ether feeding pump is mounted on the pipeline between the refined thioether buffer tank and the sulfoxide reaction device, and the hydrogen peroxide buffer tank is connected with the refined thioether buffer tank through a pipeline between the refined thioether buffer tank and the sulfoxide reaction device. The hydrogen peroxide buffer tank is connected with the sulfoxide reaction device through a pipeline, and a hydrogen peroxide feeding pump is mounted on the pipeline between the hydrogen peroxide buffer tank and the sulfoxide reaction device. According to the production device for producing dimethyl sulfoxide by using the micro-channel reactor, mixing, heat exchange and reaction are integrated by using the micro-channel reactor, so that dimethyl sulfide and hydrogen peroxide are fully mixed, reaction heat is removed while the reaction is rapid, and the reaction is better controlled.

The invention belongs to the technical field of organic synthesis, and discloses a symmetric disulfide compound containing a sulfoxide group and application of the symmetric disulfide compound in glycosylation reaction, and the structural general formula of the compound is as shown in formula (I). According to the present invention, the compound represented by the structural general formula (I) contains sulfoxide and disulfide structures, and the sulfinyl forming the sulfoxide and the disulfide bond-containing group are located at the ortho-position of the aromatic ring, such that the compound can be used as the activation reagent for the glycosylation reaction, and particularly, activation of the glycosyl donor and glycosylation reaction can be efficiently promoted by only using 0.25 times of equivalent weight of the glycosyl donor, so that the use of a highly toxic, expensive, unstable or metal-containing activating reagent is avoided, and the problems that the activating reagent of the thioglycoside donor in the existing glycosylation reaction is unstable, is not easy to prepare and often needs equivalent weight or excessive amount are solved.

The invention belongs to the technical field of organic synthesis, and particularly relates to a 3-fluoroisoquinoline-4-alcohol compound and a preparation method and application thereof.The preparation method comprises the steps that substituted 2-azido-2-fluoro-2, 3-dihydro-1H-indene-1-ketone reacts with a solvent; adding an extracting agent for extraction, taking an organic phase, drying, filtering and concentrating to obtain a crude product; and purifying to obtain the 3-fluoroisoquinoline-4-alcohol compound. The solvent is prepared from dimethyl sulfoxide, N, N-dimethyl formamide, acetonitrile, isopropanol, tetrahydrofuran, 1, 4-dioxane, dichloromethane and chloroform. Compared with the prior art, the invention solves the problems that the synthesis of isoquinoline compounds in the prior art needs multi-step reaction, the reaction conditions are harsh, and the tolerance of functional groups is poor. According to the scheme, the 3-fluoroisoquinoline-4-alcohol compound is obtained through one-step chemical reaction, and the method has the advantages that raw materials are simple and easy to obtain, the substrate range is wide, the reaction is mild, the yield is high and the like.

An electrochemical method for preparing N-arylsulfonylimine compound, comprising the following steps: in air atmosphere, a sulfoximine compound and an alpha-keto acid are added into a reactor in a molar ratio of 1:2, an electrolyte tetrabutylammonium tetrafluoroborate, a catalyst nickel bromide are added, and then an acetone solution is added; the mixture is stirred by a magnetic stirring device, and is dissolved; two electrodes are inserted, a graphite electrode is used as a positive electrode, and a platinum sheet electrode is used as a negative electrode; 6mA of current is passed, and the current passing time is 3h; after the reaction is completed, the solvent is removed by vacuum evaporation to obtain a crude product, and the N-arylsulfonylimine compound is obtained by column chromatography purification. Compared with a traditional synthesis method, the method has the advantages that the reaction condition is mild, can be successfully carried out at room temperature, operation is simple, all operations can be carried out in an open system, an electric current is used as an oxidation method, pollution of a chemical oxidant is avoided, raw materials are easy to obtain, functional group compatibility is good, and the scope of application of a substrate is wide.

The invention provides a preparation method of a recombinant human blood coagulation factor VIII and a product of the recombinant human blood coagulation factor VIII. The preparation method comprises the step of culturing a mammalian cell strain for expressing the recombinant human blood coagulation factor VIII in a serum-free culture medium of a compound containing copper ions and methionine sulfoximine. By adopting the preparation method provided by the invention, the purity of the recombinant human blood coagulation factor VIII product can be further improved on the basis of keeping the high activity and high yield of the recombinant human blood coagulation factor VIII product obtained by culture.

The invention relates to the technical field of organic chemistry, in particular to a method for synthesizing a benzothiophene coupling product through a non-metal-participated anchoring-migration strategy. The method comprises the following steps: taking a benzothiophene compound or a benzothiophene sulfoxide compound as a reaction substrate, mixing the reaction substrate with an aryl nucleophilic reagent in the presence of an anhydride activator and a solvent, and carrying out nucleophilic substitution reaction to obtain benzothiophene sulfonium salt; the preparation method comprises the following steps: mixing benzothiophene sulfonium salt with an organic solvent, and carrying out metal-catalysis-free intramolecular migration reaction to form a carbon-carbon bond at the C2 site of benzothiophene, thereby obtaining the benzothiophene coupling product. The preparation conditions are mild, the operation is simple and convenient, a traditional oxidation addition-reduction elimination process is replaced by an anchoring-migration strategy, protection of a noble metal catalyst, a complex ligand, strong base or inert gas is not needed, and the problems of high cost, metal residues, harsh reaction conditions and limited substrate applicability in the prior art are fundamentally solved.

The invention relates to a combined structure of small-diameter tower plates, which is mainly used for liquid collection, distribution and mass transfer processes, and is particularly suitable for synthesis and refining processes of dimethyl sulfide (DMS) and dimethyl sulfoxide (DMSO). The device comprises a tray (1), an upper flange (2), a clamping piece (3), a lower flange (4), a tubular distributor (5) and a packed bed layer limiter / distribution guide plate (6) from top to bottom, the tower tray (1) adopts a radial flow design, and liquid descends from the middle to flow towards the periphery and then flows from the periphery to the middle; and the tubular distributor (5) and the packed bed layer limiter / distribution guide plate (6) are combined into a whole. According to the small-diameter tower plate structure, the mass transfer efficiency is remarkably improved.

The invention relates to the technical field of synthesis of ester compounds, in particular to a preparation method of an ester compound based on a sulfur trioxide compound. The method comprises the following steps: by taking a sulfur trioxide compound as a carboxylic acid activating agent and taking a carboxylic acid-containing compound and a hydroxyl-containing compound as raw materials, carrying out esterification reaction at room temperature in a reaction system of an alkali substance, a sodium salt stabilizer and a solvent, activating carboxylic acid by sulfur trioxide to form an active intermediate, and reacting the active intermediate with hydroxyl to generate an ester compound. The ester compound based on the sulfur trioxide compound is obtained, and sodium sulfate precipitate is obtained at the same time. According to the method, acyl chloride, thionyl chloride or unstable condensation reagents with high corrosivity are not used in the reaction, chlorine-containing wastewater is not generated, the reaction is carried out at room temperature, heating or high temperature is not used, the reaction condition is mild, the product is easy to separate, the use of organic solvents can be effectively reduced through post-treatment, and the product yield is relatively high.

The invention relates to a method for producing mecobalamin by using a micro-channel reactor, which comprises the following steps: firstly, introducing a reaction mixed solution of cyanocobalamin, cobalt chloride, sodium borohydride and purified water into a first micro-channel reactor for reduction reaction; the obtained cyanocobalamin solution in the reduction state is introduced into a second microchannel reactor to be subjected to a methylation reaction with a trimethylsulfoxide iodide solution, and finally, an obtained mecobalamin solution is subjected to post-treatment to obtain a finished product. Compared with the prior art, the micro-channel reactor is used for continuous production, the mass and heat transfer effect is good, the reaction temperature can be accurately controlled, side reactions are further reduced, and the product quality is effectively improved.

The application discloses a modified organosilicon defoaming agent and a preparation method thereof, and relates to the technical field of defoaming. The modified organosilicon defoaming agent and the preparation method thereof comprise the following components by mass ratio: 89.57 g of liquid mercaptan silicone oil, 20.30 g of triethylamine, 89.57 g of dimethyl sulfoxide, 3.45 g of a methyl-terminated allyl polyoxyethylene ether, 13.80 g of a methyl-terminated allyl polyoxypropylene ether, 0.34 g of azobisdimethyl isobutyronitrile, 32.25 g of butyl acetate, 19.29 g of 2-bromoisobutyrate methyl ester, a magnesium sulfate and sodium chloride aqueous solution, a coupling agent and a thickening agent. The modified organosilicon defoaming agent has good defoaming performance and bubble inhibiting performance, has strong compatibility with different emulsions, and has defoaming performance and bubble inhibiting performance equivalent to polyether defoaming agents in a water-based resin system.