109 results about "Sodium iodide" patented technology

The invention provides a preparation method of an acid-resistant and chlorine-corrosion-resistant porous composite electrode and a device constructed on the basis of the electrode and used for preparing hydrogen and chlorine by electrolyzing a sodium chloride solution, two cavities are provided, an acid or neutral saturated sodium chloride solution is filled in the cavities, the cavities are separated by a proton exchange membrane or a diaphragm, and the proton exchange membrane or the diaphragm is filled in the cavities. And in the electrolysis process, the cathode generates high-purity hydrogen, the anode generates high-purity chlorine, the chlorine is absorbed by sodium hydroxide in the gas collection bottle and generates sodium hypochlorite, or the chlorine is introduced into a sodium bromide / sodium iodide solution to replace bromine / iodine elementary substances, and the chlorine is discharged from the gas collection bottle. The sodium hypochlorite solution and the bromine / iodine water are used for disinfection and sterilization experiments. The corrosion-resistant porous composite electrode for electrolysis of an acidic or neutral saturated sodium chloride solution is prepared, the electrolysis voltage of the corrosion-resistant porous composite electrode is further reduced by loading a cathode / anode catalyst, and an acidic or neutral saturated sodium chloride solution electrolysis device constructed based on the electrode can be used for preparing high-purity hydrogen and chlorine.

The invention belongs to the technical field of leakage detection, and discloses a gas leakage detection machine, which comprises a base, the side surface of the base is fixedly connected with a support frame, the top of the support frame is fixedly provided with a gas supply assembly, and the top of the base is slidably provided with a spraying ring. A layer of yellow bromine water is attached to the outer surface of the to-be-detected piece, the internal hydraulic pressure is enhanced along with more and more sodium iodide solutions fed into the to-be-detected piece, and the sodium iodide solutions seep along leakage gaps of the to-be-detected piece and react to change color to be red when making contact with the yellow bromine water attached to the outer surface in a spraying mode. By observing the color change condition of the outer surface of the to-be-detected piece, the leakage condition of the surface of the to-be-detected piece is directly obtained, the point and the leakage amplitude are determined, the detection of the leakage condition of the device during actual airtightness detection is greatly improved, actual leakage detection is simple and convenient, the leakage detection result is visual and comprehensive, the detection step of adding leakage points is avoided, and the detection efficiency is improved. The actual detection efficiency is comprehensively improved while the detection effect is improved, and the use effect is good.

The invention discloses a preparation method of diiodosilane, and belongs to the technical field of material synthesis. The preparation method of diiodosilane comprises the following steps: adding a first iodine source and a second iodine source into a closed reactor in an inert gas atmosphere, and dissolving the first iodine source and the second iodine source in a solvent to form a uniform solution; and reducing the temperature, and adding liquid dichlorosilane. Raising the temperature to 30 to 80 DEG C and reacting; and after the reaction is finished, heating at reduced pressure, rectifying and purifying to obtain the high-purity electronic-grade diiodosilane. The first iodine source is lithium iodide, the second iodine source is at least one of sodium iodide or potassium iodide, and the solvent comprises at least one of acetonitrile, acetone, diethyl ether or ethanol. Lithium iodide and sodium iodide or potassium iodide are compounded, a specific solvent is matched, and a one-step method is used for testing, so that the input cost of raw materials is reduced, the experimental steps are simplified, the reaction rate of a reaction system can be improved, and the purity of a diiodosilane product is improved.

The invention discloses a method for extracting micro-plastics in soil of a refuse landfill. The method comprises the following steps: pretreating a refuse landfill soil sample to obtain sample soil; the sample soil and an extracting agent are fully mixed and oscillated and then stand for layering, first supernate is obtained, the extracting agent is added at least twice, the types of the extracting agent added each time are different, and the extracting agent added each time is one of saturated sodium chloride, saturated sodium bromide and saturated sodium iodide; the first supernate is extracted and fully mixed with a digesting agent, the mixture is shaken and then stands for layering again, second supernate is obtained, and the digesting agent is at least one of 30% hydrogen peroxide, a Fenton reagent, pepsin and trypsin; and filtering the second supernatant to obtain the micro-plastic. Therefore, the extraction method provided by the embodiment of the invention has multiple technical effects of high efficiency, deep digestion, accurate filtration, wide applicability, environmental friendliness and the like.

The invention discloses a sodium iodide probe assisted gold nanoparticle-polyarginine-polylysine electrochemical sensor and an application thereof. The composite electrode provided by the invention comprises an electrode substrate and a nano composite film modified on the surface of the electrode substrate, the nano composite membrane comprises gold nanoparticles, polyarginine and polylysine. The invention further provides an electrochemical sensor which is constructed by combining the sodium iodide probe and the composite electrode and is used for detecting nitrite. The electrochemical sensor has the advantages of simplicity, rapidness, low detection limit, wide response range, good reproducibility, high selectivity and the like. The electrochemical sensor can be used for measuring the content of nitrite in beef and tap water samples, the recovery rate is satisfactory, and the electrochemical sensor has potential application prospects in the aspects of food safety and environmental protection.

The invention discloses a preparation method of atomic layer deposition synergistic doping modified sodium vanadate, which uses water as solvent, anhydrous sodium iodide and monohydrated vanadium oxyphosphate as sodium source, vanadium source and phosphorus source, and introduces cobalt acetate tetrahydrate and nickel acetate tetrahydrate, and realizes one-step hydrothermal synthesis of HNaV6O assembled by nanosheets and co-embedded with cobalt ions, nickel ions and phosphate ions by synergistically controlling their concentration and ratio, reaction temperature, reaction time and other parameters. 16 ·4H2O nanoflower structure. This method has a simple reaction process, low temperature, easy control, and does not require large equipment and harsh reaction conditions. On this basis, the atomic layer deposition technology was used to successfully realize the cobalt ion, nickel ion and phosphate ion co-embedded HNaV6O with ultra-thin nanoscale metal oxides. 16 Uniform coating of 4H2O positive electrode material. The present invention provides the application of the material in the positive electrode material of sodium ion battery.

The invention belongs to the field of fine chemical engineering, and discloses a method for synthesizing 2, 3-dimethyl-2-isopropyl butyronitrile, which comprises the following steps of: adding an organic amine solvent into a high-pressure reaction kettle, adding sodium amide, sodium iodide and a phase transfer catalyst into the reaction kettle under the protection of nitrogen and in a stirring state, stirring for a certain period of time, and reacting for 2-3 hours to obtain 2, 3-dimethyl-2-isopropyl butyronitrile. Dropwise adding a mixed solution of propionitrile and 2-bromopropane into the reactor, controlling the dropwise adding speed and the reaction temperature, continuously reacting for a period of time after the dropwise adding is finished to obtain a reactant solution, cooling the reactant solution, adding water, standing for layering, collecting an organic phase, distilling the organic phase at normal pressure to recover a solvent, and rectifying at reduced pressure to obtain 2, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3-pentanediol. According to the method, the sodium iodide, the phase transfer catalyst and the organic amine have a synergistic effect, so that the reaction time is shortened, and the yield of the product is improved.

The invention relates to the technical field of iodide content detection, in particular to a method for determining radiochemical purity and iodine content of sodium iodide capsules for diagnosis by HPLC (High Performance Liquid Chromatography), which comprises the following steps: setting chromatographic conditions, and connecting a radioactive flow detector and an ultraviolet detector in series; preparing a disodium hydrogen phosphate solution, a glucose solution, a vitamin C solution, a first control solution, a potassium iodate solution, a second control solution, a carrier solution, a first sample solution, a second sample solution, a negative control solution and a test solution; and determining the radiochemical purity and iodide content of the first sample solution and the second sample solution in three batches based on the chromatographic conditions and the determination standard. According to the method, test parameters such as capsule sample analysis time, a pretreatment mode and a sample size are optimized, the radiochemical purity of the capsule is accurately determined, and the iodide content is controlled, so that the problem that main components cannot be accurately quantified and potential radioactive impurities cannot be detected by a traditional diagnosis sodium iodide [131I] capsule determination method is solved.

The invention discloses a preparation method of 1-fluoromethyl methyl carbonate, which is characterized by comprising the following steps: 1, 1-chloromethyl methyl carbonate is dissolved in a mixed solvent, the mixed solvent comprises an organic phase and a water phase, and the water phase is deionized water; adding a catalytic amount of iodized salt and an excessive amount of acidic fluorination reagent, and carrying out nucleophilic fluorination reaction at 25-80 DEG C; the iodized salt is selected from one of sodium iodide, potassium iodide and tetrabutylammonium iodide, and the feeding molar ratio of the iodized salt to the 1-chloromethyl methyl carbonate is 0.05-0.2; and 2, after the reaction is completed, washing the reaction liquid with water, concentrating to remove the organic solvent, and carrying out reduced pressure rectification on the concentrated liquid to obtain the 1-fluoromethyl methyl carbonate product. The method has the advantages that reaction conditions are mild and controllable, the process is simple, aftertreatment is convenient, the product purity is 99.6% or above, the yield is generally 91% or above, the highest yield can reach 96.76%, the product purity and yield are both greatly improved, and industrial production is greatly facilitated.

The present invention discloses a preparation method of cobalt-doped and synergistically MXene-coated sodium vanadate composite powder. Using water as a solvent, sodium iodide anhydrous and vanadyl phosphate monohydrate as the sodium source and vanadium source, and introducing cobalt acetate tetrahydrate, by synergistically controlling parameters such as concentration and ratio, reaction temperature, reaction time, filling ratio, etc., the synthesis of HNaV6O embedded with cobalt ions assembled by nanosheets through a one-step hydrothermal method is achieved. 16 Using CTAB, the etched Ti3C2Tx and HNaV6O 16 ·4H2O are compositely assembled through electrostatic coupling, and finally cobalt-doped and synergistically Ti3C2Tx-coated HNaV6O 16 ·4H2O is prepared; the present invention improves the crystal structure and electronic conductivity of HNaV6O 16 ·4H2O, enhances its capacity and cycle stability, and the present invention also discloses the application of this material in the cathode material of sodium-ion batteries.

The invention belongs to the technical field of organic synthesis. The invention particularly relates to a synthesis method of chiral beta-diaryl ethanol. The physiological activity, the pharmacological action and the material performance of the chiral molecule are directly determined by the spatial configuration of the chiral molecule. Therefore, efficient construction of chiral compounds is always the core research direction of organic synthesis and medicinal chemistry. Wherein the chiral beta-diaryl ethanol is a kind of key intermediates with irreplaceable application value. According to the invention, the Suzuki-Miyaura type asymmetric ring-opening coupling reaction of nickel catalyzed aryl epoxy and aryl boric acid with high stereoselectivity is realized, and the asymmetric ring-opening coupling reaction is used for synthesizing chiral beta-diaryl alcohol compounds. The method is wide in substrate compatibility and raw material source, mild in reaction condition, free of exogenous alkali and convenient to operate. An aryl epoxy compound and arylboronic acid are used as raw materials, diethylene glycol dimethyl ether nickel bromide is used as a catalyst, chiral biimidazoline is used as a ligand, under the promotion of sodium iodide, reaction is performed in an ethanol solvent according to the following reaction formula at the temperature of 50 DEG C for 10 hours, and the chiral beta-diaryl ethanol compound with the high ee value is obtained.

The invention discloses a method for preparing 2, 5-diformyl furan by selectively oxidizing 5-hydroxymethylfurfural, which comprises the following steps of: reacting 5-hydroxymethylfurfural serving as a raw material, air or oxygen serving as an oxidant, nitrate or ferric salt and sodium iodide serving as main active components of a catalyst and DMSO (dimethylsulfoxide) serving as a solvent at the temperature of between 80 and 160 DEG C for a certain time under the condition of normal pressure, and separating a product to obtain the 2, 5-diformyl furan. The ferric salt is ferric nitrate nonahydrate, and the catalyst is 2, 5-diformyl furan. The dosage of the ferric salt is 0 to 0.50 mmol; the use amount of the sodium iodide is 0 to 0.50 mmol. According to the method, DMSO is adopted as a solvent, the used catalyst is cheap and easy to obtain, the yield of 2, 5-diformyl furan can reach 95% at most after the reaction is carried out at 140 DEG C for 20 h, the requirement for equipment is low, and the method is suitable for industrial production.

The present invention provides a method for producing a high-purity carboxylic acid containing aryl ester that suppresses generation of oligomers and does not require a purification step with low productivity such as column chromatography and the like, and a method for producing cationic lipids. A method for producing an aryl ester-containing carboxylic acid (1), including the following steps: 1) a step of reacting a compound (7) using potassium tert-butoxide and tert-butyl alcohol in the presence of an aprotic solvent to obtain a compound (11), 2) a step of reacting the compound (11) with a compound (13) using a condensing agent to obtain a compound (12), and 3) a step of deprotecting the tert-butyl group of the compound (12) by using trifluoromethanesulfonic acid, methanesulfonic acid, a combination of TMS-Cl and sodium iodide, or TMS-I in an organic solvent to obtain the compound (1) (A is phenyl having -O-C(=O)R20 group, etc., and B is phenyl having hydroxy group, etc.).

The invention discloses a nuclear waste liquid gamma detection device which is communicated with a nuclear waste liquid discharge pipeline and comprises a measuring cylinder for containing nuclear waste liquid and an annular sodium iodide crystal detector fixedly assembled in the measuring cylinder. The maximum outer diameter of the annular sodium iodide crystal detector is smaller than the inner diameter of the measuring cylinder, and the distance between the bottom of the annular sodium iodide crystal detector and the bottom of the measuring cylinder is L; the annular sodium iodide crystal detector is provided with an annular sodium iodide crystal and an annular shell, the sodium iodide crystal is arranged in the shell, and the top of the shell is fixedly connected with a plurality of photomultiplication and signal processing assemblies coupled with the sodium iodide crystal. The nuclear waste liquid gamma detection device has the characteristics of low detection lower limit and high efficiency.

The invention relates to the field of organic synthesis, in particular to a synthetic method of (2R, 4S)-N-BOC-4-hydroxypiperidine-2-methyl formate. The synthesis method of (2R, 4S)-N-BOC-4-hydroxypiperidine-2-methyl formate comprises the following steps: mixing a material A, a material B, potassium carbonate, sodium iodide and a solvent, and reacting to obtain a material C; mixing the material C, the material D, triethylamine and a solvent, and reacting to obtain a material E; mixing the material E, ammonia water and a solvent, and reacting to obtain a material F; and mixing the material F, di-tert-butyl dicarbonate, a palladium carbon catalyst and a solvent, and carrying out a reaction to obtain the (2R, 4S)-N-BOC-4-hydroxypiperidine-2-methyl formate. The process route is easy to operate and has no special dangerous reaction. Reaction materials are cheap and easy to obtain, and the prepared product is high in purity.

The invention discloses a method for underwater online rapid analysis of nuclear pollution of a seawater environment, namely a method for rapidly detecting 137Cs in the seawater environment. An indoor simulation experiment is carried out by using a sodium iodide gamma energy disperse spectroscopy, and counting contribution of natural nuclides in seawater and the instrument per se at [640, 700] keV energy is deduced by adopting an exponential decay fitting mode, so that the technical index that the detection limit of 137Cs in seawater is reduced to 60 mBq / L when the test is carried out for 24 hours is realized. In addition, when the method is applied to a shipborne sodium iodide gamma spectrometer to test surface seawater for 17.6 hours on site, the detection limit of 137 Cs is calculated to be 6.08 mBq / L. The system and the method can be applied to emergency monitoring of radioactive sites in seawater, are helpful for improving the existing seawater environment radioactivity monitoring capability, and provide technical support for marine radioactivity supervision.

The present invention belongs to the technical field of automatic analysis and measurement in uranium purification and hydrometallurgical processes, and specifically relates to an online high-concentration uranium analysis and detection device for uranium purification processes. A sodium iodide crystal is disposed within a shielding component, a photomultiplier tube is coupled below the sodium iodide crystal, an electronic circuit is disposed below the photomultiplier tube, and a cable is disposed below the electronic circuit. The cable passes through the shielding component, which is provided with a support frame connected to the photomultiplier tube. A through-hole is formed in the sodium iodide crystal, through which a polytetrafluoroethylene (PTFE) tube passes. The two ends of the PTFE tube respectively serve as a solution inlet and a solution outlet, both of which pass through the shielding component. The present invention is suitable for measuring high-concentration uranium in the automatic analysis of uranium purification and hydrometallurgical processes, and measures the uranium concentration in the solution without the addition of any chemical reagents.

The application provides a method for preparing alpha-sulfonamidyl acetal compounds from fatty aldehyde and sulfonamide, and belongs to the technical field of organic chemical synthesis, and comprises the following steps: step 1: fatty aldehyde, sulfonamide, sodium iodide, sodium carbonate peroxide and methanol or ethanol are added into a reaction container for mixing, a reaction mixture is obtained by reacting at a temperature of 50-80 DEG C for 16-24 hours; step 2: after the reaction mixture is purified, alpha-sulfonamidyl acetal compounds are obtained. The sulfonamide drugs used in the method are all commercially available, the fatty aldehyde is commercially available or is prepared by simply oxidizing commercially available fatty alcohol, and the pre-catalyst sodium iodide and the oxidant sodium carbonate peroxide are also cheap and easy to obtain; the method has a wide applicable range of substrates and good compatibility for sensitive groups; the reaction does not need transition metal catalysis, the alcohol used is used as a raw material and a solvent, and the only by-product is water, so that the method has the characteristics of high atom economy and green environmental protection.

The invention belongs to the field of chemical reagents, and particularly relates to a preparation method of alcohol-free acetone. The preparation method comprises the following steps: S1, carrying out primary adsorption by using a 4A molecular sieve and a 5A molecular sieve; s2, carrying out secondary adsorption by using a 4A molecular sieve, a 5A molecular sieve and a 10X molecular sieve; s3, adding sodium iodide into the acetone solution subjected to secondary adsorption treatment according to a solid-to-liquid ratio of 1: 4; s4, washing the crystal with absolute ether at least twice, then carrying out solid-liquid separation, and heating and distilling at 80-100 DEG C; s5, repeating S3 and S4, and carrying out secondary crystallization and crystal cleaning; s6, carrying out dehydration treatment on a crude product subjected to secondary distillation by using a 3A molecular sieve; and S7, carrying out rectification on the dehydrated crude product alcohol-free acetone in a temperature range of 80-100 DEG C. According to the technical scheme, before sodium iodide is added for adduct crystallization and purification, a step-by-step molecular sieve adsorption pretreatment process is introduced. According to the process, two molecular sieves with matched pore diameters and polarities are adopted, an industrial-grade acetone raw material is sequentially subjected to two times of adsorption treatment, and the purpose of synergistic purification is achieved by targeting different impurities.

The invention relates to the field of organic synthesis, in particular to a synthetic method of (2R, 4S)-N-BOC-4-hydroxypiperidine-2-methyl formate. The synthesis method of (2R, 4S)-N-BOC-4-hydroxypiperidine-2-methyl formate comprises the following steps: mixing a material A, a material B, potassium carbonate, sodium iodide and a solvent, and reacting to obtain a material C; mixing the material C, the material D, triethylamine and a solvent, and reacting to obtain a material E; mixing the material E, ammonia water and a solvent, and reacting to obtain a material F; and mixing the material F, di-tert-butyl dicarbonate, a palladium carbon catalyst and a solvent, and carrying out a reaction to obtain the (2R, 4S)-N-BOC-4-hydroxypiperidine-2-methyl formate. The process route is easy to operate and has no special dangerous reaction. Reaction materials are cheap and easy to obtain, and the prepared product is high in purity.

The invention provides a method for synchronously extracting and quantifying micro-plastics and tire abrasives in sludge and application of the method, and belongs to the technical field of residual sludge pollution monitoring. The method comprises the following steps: firstly, freeze-drying and grinding the excess sludge, pre-oxidizing by using a hydrogen peroxide solution to destroy aggregates formed among MPs and TWP, clay, sand and other substances, and then heating to remove the hydrogen peroxide solution; and the residual hydrogen peroxide solution in the pre-oxidation process is prevented from being continuously decomposed in the subsequent density separation process to generate bubbles for jacking impurities to float upwards. A saturated sodium bromide solution and a saturated sodium iodide solution are adopted as flotation reagents for primary density separation and secondary density separation correspondingly, it is guaranteed that MPs and TWP with different densities are separated, impurities are removed through Fenton oxidation digestion, and interference on recognition of specific thermal cracking products of MPs and TWP is reduced. The method provided by the invention can quickly and accurately evaluate the mass concentration pollution status of MPs and TWP in the excess sludge.

The application discloses a preparation and purification method of high-purity radioiodine-labeled antigen. The method comprises the following steps: pre-activating carrier-free sodium iodine[125I] solution in an orthogonal solvation sensitization buffer containing lithium sulfate, 18-crown-6 and beta-cyclodextrin; adding antigen and chloramine-T for a labeling reaction; and performing magnetic separation and purification by using a suspension containing adamantane-modified magnetic microspheres and quaternary ammonium salt-modified strong anion exchange magnetic microspheres after the reaction. The orthogonal solvation effect is used to enhance the nucleophilic activity of iodine ions, and the amount of oxidizing agent is reduced to reduce protein damage; impurities are quickly removed through the double mechanisms of electrostatic adsorption and host-guest recognition. The application has the advantages of high labeling efficiency, high radiochemical purity of the product and complete retention of biological activity.

Methods and compositions for treating various indications by lessening oxidative stress in a patient are provided. A pharmaceutical composition comprises between about 0.001% to about 10.0%, or more specifically between about 0.015% to about 5%, sodium iodide or catalase by weight. The iodine ion or the catalase dissociates hydrogen peroxide into water and molecular oxygen to interrupt biological events that result in negative side effects. The pharmaceutical composition further comprises in some cases a reducing agent or various carrier materials. The pharmaceutical composition is in some cases formulated for a variety of delivery methods.

The invention belongs to the technical field of terahertz (THz) wave absorbing materials, and particularly provides a transparent flexible terahertz absorbing material based on ionic conduction loss and a preparation method thereof, which are used for meeting electromagnetic interference suppression requirements in high-transmittance scenes such as aviation optical windows, radomes and sensors. The transparent flexible terahertz absorbing material is composed of an upper anti-reflection layer, a lower anti-reflection layer and polymer-based hydrogel sealed between the upper anti-reflection layer and the lower anti-reflection layer, and the polymer-based hydrogel takes polyacrylamide (PAM) as a framework and water as a filling medium; the filling medium contains salt ions, and the salt ions are one or more of lithium chloride, sodium chloride, potassium chloride, cesium chloride, sodium fluoride, sodium bromide and sodium iodide; the transparent flexible terahertz absorber has the advantages of high wave absorbing performance, excellent flexibility and high transparency.

The invention discloses a high-barrier puncture-resistant food packaging film and a preparation method thereof, and relates to the technical field of food packaging films. When the high-barrier puncture-resistant food packaging film is prepared, firstly, polystyrene is grafted with 2-vinylhexafluoroisopropanol, then the grafted polystyrene reacts with 2-chloro-2-oxo-1, 3, 2-dioxaphospholane, and then the grafted polystyrene reacts with 4-(dimethylamino)-2-methoxybenzonitrile to obtain modified polystyrene, and then the modified polystyrene reacts with 2-chloro-2-oxo-1, 3, 2-dioxaphospholane and 4-(dimethylamino)-2-methoxybenzonitrile to obtain the high-barrier puncture-resistant food packaging film. Secondly, reacting the pretreated vermiculite flakes with hydrogen-containing silicone oil and 1-(5-vinyl-2-hydroxyphenyl) ethanone, then reacting with phosphorus oxychloride and N, N-dimethylformamide, and then reacting with hydroxylamine hydrochloride and sodium iodide to obtain modified vermiculite flakes; and finally, carrying out melt blending on the modified polystyrene, the modified vermiculite sheets and zinc chloride, preparing into a film through a blow molding machine, and reacting with iodine and aluminum powder to prepare the high-barrier puncture-resistant food packaging film. The high-barrier puncture-resistant food packaging film prepared by the invention has good barrier property, antibacterial property and anti-aging property.

The invention relates to a reductive coupling method of aryl sulfide and nitrous oxide, which only needs to use an air bag and a common reaction tube, does not need to use a pressure-resistant tube with potential safety hazards, and takes cobalt bromide (CoBr2) as a catalyst, 4, 7-diphenyl-1, 10-phenanthroline (4, 7-diphe-1, 10-phen) as a ligand, sodium iodide (NaI) as an additive and zinc powder (Zn) as a reducing agent to prepare the aryl sulfide and nitrous oxide reductive coupling method. The method comprises the following steps: under the condition of nitrous oxide of one atmospheric pressure, putting thiazole thioether and derivatives thereof into N, N-dimethylacetamide (DMA), reacting for 12 hours under the condition of 100 DEG C, and then performing column chromatography purification through an automatic column chromatography machine to obtain thiazolone and derivatives thereof. Some important drug molecules can be synthesized by adopting the method.

The invention relates to a synthetic method of optically pure (2R, 3R)-dihydroquercetin, which comprises the following steps of: a, reacting m-dimethoxybenzene with ethyl oxalyl chloride under the protection of inert gas and catalysis of Lewis acid to obtain a compound V; b, under the catalysis of divalent cobalt salt, selectively activating the ortho-position C-H bond of the compound V, and reacting with 3, 4-dimethoxybenzyl alcohol to obtain a compound IV; c, carrying out intramolecular cyclization on the compound IV under the alkaline condition of inert gas protection to obtain a compound III; d, under protection of inert gas and catalysis of a rhodium complex formed by monovalent rhodium salt and a chiral phosphine ligand in situ, hydrogenation reduction of double bonds is correspondingly and selectively realized by the compound III, and a compound II is obtained; e, under the catalysis of sodium bromide or sodium iodide, the compound II reacts with aluminum trichloride for demethylation, and optically pure (2R, 3R)-dihydroquercetin is obtained.The synthetic raw materials are low in price and easy to obtain, operation is easy, the yield and optical purity are high, and the method is suitable for industrial production.

The invention discloses a preparation method of L-2, 4-diaminobutyric acid dihydrochloride, which comprises the following steps: (1) taking L-homoserine as an initial raw material, and reacting with concentrated hydrochloric acid in the presence of a zinc chloride / ferrous chloride synergistic catalyst to prepare L-2-amino-4-chlorobutyric acid hydrochloride; (2) after neutralization, carrying out an acylation reaction with ethyl chloroformate to generate N-ethoxycarbonyl-L-4-chlorobutyric acid; (3) carrying out esterification with ethanol so as to obtain N-ethoxycarbonyl-L-4-chlorobutyl amino acid ethyl ester; (4) under the catalysis of sodium iodide, carrying out nucleophilic substitution reaction with phthalimide potassium salt, and cooling, crystallizing and purifying the key intermediate by dropwise adding water to obtain L-2-[(ethoxycarbonyl) amino]-4-phthalimide ethyl butyrate; and (5) finally, hydrolyzing for deprotection, and concentrating and crystallizing to obtain the L-2, 4-diaminobutyric acid dihydrochloride. The method has the advantages of mild reaction conditions, simplicity and convenience in operation, high total yield and the like, and is suitable for large-scale industrial production.

The invention belongs to the field of drug synthesis, and particularly relates to a preparation method of sodium 2, 3-dimercaptopropanesulfonate, which comprises the following steps: cooling a sodium hydroxide solution, reacting with thioacetic acid, adding 2, 3-dibromopropanesulfonic acid and sodium iodide, and heating to react to obtain a 2, 3-bis (acetylthio) propanesulfonic acid solution; the preparation method comprises the following steps: heating a 2, 3-bis (acetylthio) propanesulfonic acid solution and dilute sulphuric acid to react to obtain a 2, 3-dimercaptopropanesulfonic acid solution; the preparation method comprises the following steps: adding sodium acetate into a 2, 3-dimercaptopropanesulfonic acid solution to react to obtain a 2, 3-sodium dimercaptopropanesulfonate crude product, and refining to obtain a 2, 3-sodium dimercaptopropanesulfonate finished product. By optimizing the molar ratio of 2, 3-dibromopropanesulfonic acid, thioacetic acid, sodium hydroxide and sodium iodide, the reaction temperature, the solvent volume, the refining temperature, the refining solvent volume and other parameters, the purity of 2, 3-sodium dimercaptopropanesulfonate reaches 99.4%, and the yield reaches 54.5%. Sodium iodide is added as a catalyst to effectively improve the reaction efficiency and the product purity. The reaction does not need to adopt one-class metal lead, and the pollution is small.

The application provides a bromine-based leaching reagent system and a method for recycling precious metals from waste circuit boards, and belongs to the technical field of hydrometallurgy. The application takes stable bromine-based strong oxidant, sodium bromide and sodium iodide as the leaching reagent system, controls the bromine volatilization loss to be below 5% through the slow-release bromine mechanism, reduces the bromine consumption by more than 15% compared with the traditional liquid bromine leaching process, simultaneously introduces sodium iodide as a catalytic additive, and significantly reduces the sodium bromide consumption. The weak acid leaching environment is adopted, the leaching efficiency is ensured, and the equipment corrosion problem is effectively reduced. The developed "distillation-precipitation" coupling process realizes efficient recovery of silver and synchronous regeneration of bromine reagent, so that the bromine recycling rate is more than 80%. Through the construction of a gold selective reduction-silver distillation precipitation-palladium solvent extraction hierarchical separation system, efficient recovery of precious metals is realized. The application greatly reduces the processing cost through the recycling of bromine reagent, has significant industrial application value and broad market prospect.