181 results about "Hydroxylamine Hydrochloride" patented technology

The application discloses a method for preparing a CGRP receptor antagonistic intermediate, and belongs to the field of synthesis of medical intermediates. Compound 1 is used as a raw material, reacts with hydroxylamine hydrochloride in an organic solvent to generate an intermediate 2, and then reacts in the presence of a reducing agent to obtain a remikiren intermediate 3. The application is characterized in that a large steric hindrance silicon group is used as the R substituent in the compound 1, so that high stereoselectivity is ensured in the reduction reaction. The key intermediate obtained by using the method has high chiral purity, and the operation is simple, so that the industrial production of the product in the later stage can be realized.

The invention relates to a method for synthesizing trifloxystrobin through a one-pot method, and belongs to the technical field of organic synthesis.The method comprises the following steps that 1, E-2-(2-halomethylphenyl)-2-methoxyiminoacetic acid methyl ester, m-trifluoromethyl acetophenone, hydroxylamine hydrochloride or hydroxylamine sulfate and a solvent are added into a reaction flask, then alkali is added, and after addition is completed, a heat preservation reaction is conducted; and Step 2, after the reaction is finished, filtering to remove salt, and concentrating filtrate under reduced pressure to obtain trifloxystrobin. Compared with a traditional synthesis method of the trifloxystrobin, the synthesis method of the trifloxystrobin has the advantages that the 3-trifluoromethyl acetophenone and the E-2-(2-halomethylphenyl)-2-methoxyiminoacetic acid methyl ester are used as raw materials, the trifloxystrobin is directly synthesized by a one-pot method, the reaction route is short, the raw material cost is low, and the synthesis method of the trifloxystrobin by the one-pot method has the advantages that the synthesis efficiency is high, and the synthesis cost is low. The preparation method has the advantages that the preparation of m-trifluoromethyl acetophenone oxime from m-trifluoromethyl acetophenone is not needed, the whole synthesis process is simpler and more efficient, the reaction conditions are mild, and the preparation method is suitable for industrial large-scale production.

The invention relates to the technical field of benzamide, in particular to a preparation process of 4-hydroxythiobenzamide, which comprises the following steps: S1, preparing raw materials: preparing the 4-hydroxythiobenzamide from the following raw materials in parts by weight: 80-100 parts of formic acid, 80-100 parts of hydrochloric acid, 20-30 parts of 4-hydroxybenzaldehyde, 8-12 parts of hydroxylamine hydrochloride, 8-12 parts of thioacetamide and 4-6 parts of sodium hydroxide. According to the preparation method, after 4-hydroxybenzaldehyde is subjected to activating treatment reaction, part of positive charges on aldehyde carbon are dispersed, oxygen atoms in an acetal structure are connected with the aldehyde carbon through covalent bonds to generate an electron withdrawing induction effect, the reaction sequence and the reaction path of the 4-hydroxybenzaldehyde can be controlled through aldehyde activation, and the reaction efficiency of the 4-hydroxybenzaldehyde is improved. Therefore, the generation of byproducts is reduced, and the purity of a reaction product obtained from 4-hydroxybenzaldehyde is improved.

The invention relates to a method for efficiently preparing hydroxylamine hydrochloride. The method comprises the following steps: mixing a diacetylmonoxime solution and a hydrochloric acid solution, pretreating through a pressurized nano-bubble fluidized bed, and carrying out reaction distillation under heating and pressurizing; after the reaction is finished, cooling reaction liquid, performing primary filtration and suction filtration through cross-flow filtration equipment, and collecting hydroxylamine hydrochloride crystals; and washing the crystal with absolute ethyl alcohol, recovering ethyl alcohol through cross-flow filtration equipment, and finally freeze-drying to obtain the high-purity hydroxylamine hydrochloride. The preparation method comprises the following steps: stirring quinoline-8-yl acrylate, tributyltin acrylate, 4-vinyl benzocyclobutene, ethanol and benzoyl peroxide to obtain a mixed solution; immersing the PTFE membrane subjected to low-temperature plasma pretreatment into the mixed solution, and then carrying out ultrasonic cleaning and vacuum drying to obtain a polymer modified PTFE membrane; the hydroxylamine hydrochloride prepared by the method disclosed by the invention has relatively high purity and yield, and meanwhile, the content of heavy metal ions and the content of water are effectively reduced.

The invention relates to the technical field of precious metal recovery, in particular to a method and system for recovering gold, silver, palladium and platinum from silver anode slime. S2, palladium precipitation: adding a potassium-magnesium mixture and sodium chlorate into the pre-impregnation liquid obtained in S1 to obtain palladium precipitation residues and platinum precipitation liquid; s3, separating gold; s4, platinum and palladium precipitation: adding a potassium-magnesium mixture and sodium chlorate into the gold separation liquid obtained in S3 to obtain platinum and palladium precipitation residues and platinum and palladium precipitation post-liquid; s5, gold is reduced; s6, platinum and palladium separation, wherein hydroxylamine hydrochloride is added into the platinum and palladium precipitation residues obtained in the step S4, and palladium separation liquid and platinum precipitation residues are obtained; 7, platinum purification, wherein hydroxylamine hydrochloride is added into the platinum precipitation residues obtained in the step 6, and platinum separation liquid is obtained; s8, carrying out primary palladium deposition; s9, carrying out secondary palladium deposition; and S10, palladium is reduced. The recovery rate of palladium is 99% or above, the recovery rate of platinum is 99% or above, the purity of platinum is 99.9%, the purity of palladium is 99.95%, the recovery rate of silver is 98.5% or above, and the recovery rate of gold is 99% or above.

The invention provides a preparation method of milbemycin oxime A4, which comprises the following steps: under an acidic condition, carrying out hydrolysis disaccharide removal reaction on tenvermectin B to obtain tenvermectin B aglycone; the preparation method comprises the following steps: carrying out silicon-based protection on tenvermectin B aglycone by adopting a silicon-based protection reagent to obtain 5-hydroxyl silicon-based tenvermectin B aglycone; the preparation method comprises the following steps: brominating 5-hydroxyl silicon-based tenvermectin B aglycone by adopting a brominating reagent to obtain 13-bromine-5-hydroxyl silicon-based protected tenvermectin B aglycone; the preparation method comprises the following steps: reducing 13-bromo-5-hydroxyl silicon group protected tenvermectin B aglycone by using a reducing agent to obtain 5-hydroxyl silicon group protected milbemycins A4; the milbemycins A4 protected by the 5-hydroxyl silicon group is subjected to desilicication protection treatment, and the milbemycins A4 is obtained; oxidizing milbemycins A4 by adopting an oxidizing agent to obtain 5-ketomilbemycins A4; the preparation method comprises the following steps: reacting 5-ketomilbemycins A4 with hydroxylamine hydrochloride to obtain milbemycins A4, and efficiently preparing the active component milbemycins A4 single component by taking tenvermectin B as a raw material.

The invention relates to the technical field of palladium recovery, in particular to a method for recovering palladium. According to the technical scheme, the method comprises a precipitant pre-synthesis stage, a targeted palladium precipitation stage and a multi-stage reduction purification stage, and the precipitant pre-synthesis stage comprises the step of adding 10-15 parts by mass of butanedione, 18-30 parts by mass of hydroxylamine hydrochloride and 0.1-0.3 part by mass of iron phthalocyanine into a reaction kettle. Through a composite precipitator system and a multi-stage reduction process, the method has safety and high efficiency: flammable and explosive solvents such as ethanol and highly toxic reducing agents such as hydrazine hydrate are not needed, so that the potential safety hazard of production and the environment-friendly treatment cost are remarkably reduced; high-selectivity capture and efficient reduction of palladium are achieved through magnetic separation of magnetic nano-microspheres, induced precipitation of nitrogen-doped graphene quantum dots and a staged temperature-control and pressure-control reduction technology, the palladium recovery rate and purity are high, the process period is short, operation is controllable, and the method is suitable for industrial continuous production.

The invention belongs to the technical field of rare earth material analysis, and particularly relates to an ultra-trace analysis method for a copper element in a rare earth material based on an extraction principle, and the analysis method comprises the following steps: dissolving a rare earth oxide sample with 1: 1 hydrochloric acid, and drying by distillation to obtain a sample solution; sequentially adding an ammonium citrate solution, a hydroxylamine hydrochloride solution and a copper reagent solution into the sample solution, stirring for 1-2 minutes at the rotating speed of 150-200rpm, dropwise adding ammonia water with the ratio of 1: 5 to adjust the pH value to be 9-10, and forming a complex by Cu < 2 + > and a copper reagent to obtain a complex solution; adding an extracting agent into the complex solution, oscillating and extracting for 1-2 minutes, standing and layering for 10-15 minutes, and taking a lower layer organic phase; when ultra-trace analysis is carried out on the copper in the rare earth element, through specific chemical treatment, other elements or compounds which may interfere with determination are reduced, and through collaborative optimization of chemical extraction and spectrophotometry, the lower detection limit of the copper in the rare earth element is reduced to 0.1 ppm from traditional 2ppm.

The application discloses a synthesis method of afugan, which comprises the following steps: 1-[3-chloro-5-(trifluoromethyl)phenyl]-2,2,2-trifluoroacetone and 4-acetylnaphthalene carboxylic acid are added into a solvent, a base is added, DMAP is added after complete reaction at 50-80 DEG C, acetic anhydride is added dropwise, tetrabutylammonium bromide is added after complete reaction, and an aqueous solution of sodium hydroxide and hydroxylamine hydrochloride is added, and reaction is carried out at 0-5 DEG C, so that an intermediate is obtained; the intermediate is reacted with acyl chloride under the action of DMF and dichloromethane, so that 4-(5-(3-chloro-5-(trifluoromethyl)phenyl)-5-(trifluoromethyl)-4,5-dihydroisoxazole-3-yl)-1-naphthalene carboxylic chloride is prepared; 2-amino-N-(2,2,2-trifluoroethyl)acetamide hydrochloride and a dichloromethane solution of a base are added dropwise, and reaction is carried out at 0-5 DEG C, so that afugan is obtained. The method has a short route, high yield and suitability for large-scale industrial production.

The invention relates to the technical field of uranium extraction fiber membranes, and discloses a preparation method of an MXene / PVDF / PAO photo-thermal-piezoelectric composite fiber membrane, and the preparation method comprises the following steps: S1, dissolving PAN in DMF, adding hydroxylamine hydrochloride and NaOH, and stirring to obtain a spinning solution I; s2, PVDF is dissolved in DMF, multiple layers of MXene materials are added, and a uniform spinning solution II is obtained through stirring; and S3, preparing the MXene / PVDF / PAO fiber membrane from the spinning solution I and the spinning solution II in a double-spinning form by using an electrostatic spinning device. And jointly assembling the PAO, the PVDF nano particles and the Mxene nano sheets into the electrostatic spinning membrane. Wave energy excites the piezoelectric effect of PVDF, and light energy is absorbed by Mxene. Compared with an existing scheme, water flow resistance is smaller, adsorption sites are more, and large-scale sea tests are better facilitated.

The present invention relates to a corrosion gel for weld detection, a preparation method, a corrosion method and a weld surface crack detection method, belonging to the technical field of weld detection. The corrosion gel for weld detection comprises the following raw materials: agar, water, 98% sulfuric acid, 10% hydroxylamine hydrochloride solution, p-tolylthiourea, stannous sulfate, thiourea, 10% Triton X-100 solution and 0.05% ethanol solution of o-phenanthroline derivative. The preparation method of the corrosion gel for weld detection comprises the following steps: weighing agar and dissolving it in water; sequentially adding 98% sulfuric acid, hydroxylamine hydrochloride solution, p-tolylthiourea, stannous sulfate, thiourea, Triton X-100 solution and ethanol solution of o-phenanthroline derivative; adding 100 mL of ethanol solution of o-phenanthroline derivative and mixing evenly to obtain a hot corrosion gel. A weld surface crack detection method comprises the following steps: making an indicating electrode; preparing a corrosion gel; treating the weld with the corrosion gel; evaluating the weld crack.

This invention belongs to the field of soil manganese extraction technology, and discloses a stepwise extraction method and application for manganese species in soil. First, exchangeable manganese is extracted using magnesium chloride; then, manganese carbonate and sulfides are extracted using hydrochloric acid; next, active Mn(III) bound to organic matter is extracted using pyrophosphate solution under alkaline pH; then, manganese oxides are dissolved using hydroxylamine hydrochloride; and finally, manganese bound to crystalline iron and manganese oxides is extracted using sodium dithionite solution. This stepwise extraction scheme accurately quantifies the concentration of active Mn(III) species bound to organic matter in the soil. Experimental results show that the extraction method of this invention can effectively separate different forms of manganese in soil. In particular, PP extraction successfully distinguishes Mn(III) bound to organic matter without introducing interfering substances such as iron minerals that may interfere with dissolution.

The invention discloses an organic peroxide reaction endpoint rapid detection method and application thereof, and belongs to the technical field of organic chemistry. The invention aims to solve the technical problems that the reaction endpoint of an organic peroxide initiator is difficult to judge, the generated organic peroxide is easy to decompose due to too long reaction time, and the reaction is incomplete and raw materials are remained due to too short reaction time, and provides a rapid detection method for acyl chloride residues in the organic peroxide reaction process. Therefore, the reaction endpoint is determined. According to the technical scheme, the method for rapidly detecting the reaction endpoint of the organic peroxide is characterized in that in the reaction process of an organic peroxide initiator, acyl chloride is gradually consumed, the content is reduced, and the acyl chloride completely reacts when the reaction endpoint is reached. Through reaction of different acyl chloride concentrations and hydroxylamine hydrochloride, a standard curve or a color card is established, the residual amount of acyl chloride is judged, and the reaction endpoint is accurately judged.

The application discloses a hydroxylamine hydrochloride detection method in azithromycin dry suspension, and relates to the trace detection field. The method uses isoamyl aldehyde as a derivatizing agent, generates isoamyl aldoxime by performing derivatization treatment on a sample to be measured, and then uses N-nitrosodiisopropylamine as an internal standard substance to quantitatively determine the isoamyl aldoxime by using liquid chromatography-tandem mass spectrometry. The detection method adopts an isoamyl aldehyde derivatizing agent-N-nitrosodiisopropylamine internal standard substance system, can correct detection errors caused by factors such as matrix effect, pretreatment loss and derivatization efficiency fluctuation, and improves the accuracy and sensitivity of the trace hydroxylamine hydrochloride detection result, thereby guaranteeing the safety of the medicine.

The invention relates to the technical field of graphene modification, and particularly discloses a preparation method of modified graphene for lubricating oil, which comprises the following steps: ultrasonically dispersing graphene in water to obtain a graphene dispersion liquid; potassium octadecyl benzene sulfonate is added into the graphene dispersion liquid, and a stirring reaction is performed for 10-20 min; then adding ammonium molybdate and sodium sulfide into the system, adjusting the pH value of the reaction system to 4.5-6, and reacting for 1-2 hours under the reflux stirring action at 60-110 DEG C; adding hydroxylamine hydrochloride into the reaction system, and continuously stirring to react for 2-4 hours; and finally, carrying out centrifugal separation on the reaction liquid, washing with ethanol and distilled water for multiple times, and carrying out centrifugal separation to obtain the modified graphene. According to the preparation method of the modified graphene provided by the invention, a stable and uniform lubrication enhancement layer can be constructed on the surface of the graphene in situ, so that the graphene is endowed with excellent oil solubility and oil phase dispersion stability.

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 invention relates to the technical field of organic synthesis, in particular to the field of IPC C07D239, and more particularly relates to a synthesis method of a phenyl isoxazoline compound. Comprising the following steps: step 1, using a benzaldehyde compound as an initial raw material, and reacting with hydroxylamine hydrochloride to generate a benzaldoxime compound; 2, carrying out a chlorination reaction on the benzaldoxime compound generated in the step 1 and liquid chlorine through a microchannel reactor to generate a chlorinated benzaldoxime compound; and 3, carrying out ring closing on the chlorobenzaldoxime compound generated in the step 2 and an alkene compound to obtain the phenyl isoxazoline compound. A metal catalyst is not used in the preparation method, so that the solid waste treatment cost is reduced; in the step 2, a continuous flow reaction technology of a microchannel reactor is adopted, the reaction time is shortened, compared with a kettle type intermittent process, the productivity is greatly improved, and the reaction safety is higher.

This invention relates to the field of bionanomaterials technology, and particularly to mitochondrial-targeting nanomaterials capable of releasing HNO, their preparation methods, and applications. The preparation method of the mitochondrial-targeting nanomaterials capable of releasing HNO includes the following steps: synthesis of a silanized HNO donor: hydroxylamine hydrochloride is dissolved in a mixed solvent of anhydrous tetrahydrofuran and anhydrous pyridine, and a dichloromethane solution of 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane is added. The mixture is stirred at room temperature, and after post-treatment, a silanized HNO donor is obtained; synthesis of aminated carbon dots: chitosan, ethylenediamine, and mercaptosuccinic acid are dispersed in deionized water, and concentrated hydrochloric acid is added and stirred until dissolved. This preparation method can prepare mitochondrial-targeting nanomaterials capable of releasing HNO, achieving precise delivery, controlled release, and visual tracking of HNO to cardiac mitochondria, solving the technical problems of traditional HNO donors' inability to achieve stable loading on carriers and lack of mitochondrial targeting ability.

The invention provides a preparation process and system of N-benzyl hydroxylamine hydrochloride, and the preparation process utilizes a microchannel reactor and a film concentration device to realize synthesis of a target product through a two-step method. The method comprises the following steps: firstly, continuously pumping dibenzylamine, an auxiliary agent and hydrogen peroxide into a micro-channel reactor, and carrying out accurate temperature control and efficient mixing under a micro-scale to promote an oxidation reaction to be rapidly completed so as to generate a key nitrone intermediate; the step effectively avoids the dangerous thermal runaway phenomenon possibly occurring in a traditional reaction kettle, and the operation safety is improved. Then, introducing the nitrone intermediate and hydrochloric acid into a film concentration device; in the device, the nitrone intermediate is hydrolyzed under an acidic condition, and meanwhile, a reaction solution can be quickly evaporated by a film concentration technology, so that a solvent and byproducts generated along with the reaction are efficiently removed. The thin film concentration technology not only inhibits the occurrence of side reactions, but also ensures the high yield and high purity of the final product.

The invention relates to the technical field of high polymer materials, and discloses a fully biodegradable mulching film for corn for seed production and a preparation method thereof, the fully biodegradable mulching film comprises the following components by weight: 65-75 parts of polylactic acid, 4-6 parts of modified polyester, 8-12 parts of biomass charcoal, 2-3 parts of acetyl tributyl citrate, and 0.4-0.5 part of an antioxidant 1010; the preparation method of the modified polyester comprises the following steps: synthesizing an intermediate 1 by taking 2-hydroxyadipaldehyde and hydroxylamine hydrochloride as raw materials, and then esterifying, oxidizing and curing to obtain the modified polyester. The full-biodegradable mulching film for the corn for seed production has relatively good tensile property and degradable effect.

The invention discloses a preparation method of a biochar-zinc sulfide-tungsten sulfide heterojunction composite material, and the scheme comprises the following steps: S1, dissolving sodium tungstate, hydroxylamine hydrochloride, sodium hydroxide, thiourea and zinc chloride in deionized water, and uniformly stirring to obtain a light yellow transparent reaction solution; s2, biological carbon is prepared, the reaction liquid and the biological carbon are mixed in a reaction kettle and then subjected to a hydrothermal reaction for 8-48 h at the constant temperature, and the constant temperature is any one of the temperature values ranging from 180 DEG C to 240 DEG C; s3, filtering, cleaning and drying a product obtained in the step S2 to obtain a heterojunction composite material precursor; s4, the heterojunction composite material precursor is subjected to calcination treatment in the inert gas atmosphere, the biochar-zinc sulfide-tungsten sulfide heterojunction composite material is obtained, and the calcination temperature ranges from 850 DEG C to 950 DEG C.

The invention discloses a method for sequentially extracting forms of heavy metals in an organic fertilizer, which comprises the following steps: (1) mixing the organic fertilizer with a magnesium chloride solution, and separating to obtain a first filtrate and a first residue; (2) mixing and separating the first residue and an acetic acid-sodium acetate buffer solution to obtain a second filtrate and a second residue; (3) mixing and separating the second residue and a sodium pyrophosphate solution to obtain a third filtrate and a third residue; (4) mixing and separating the third residue and the hydrogen peroxide and nitric acid solution, and mixing and separating the obtained residue and an ammonium acetate solution to obtain a fourth filtrate and a fourth residue; (5) mixing and separating the fourth residue and a hydroxylamine hydrochloride solution to obtain a fifth filtrate and a fifth residue; (6) mixing the fifth residue with aqua regia, and filtering to obtain a sixth filtrate; (7) mixing the organic fertilizer with aqua regia, and filtering to obtain a seventh filtrate; and (8) detecting the contents of heavy metal elements in the first filtrate, the second filtrate, the third filtrate, the fourth filtrate, the fifth filtrate, the sixth filtrate and the seventh filtrate.

The invention discloses a method for co-production of 2, 4-dichloro-5-fluoroacetophenone and hydroxylamine hydrochloride, and belongs to the technical field of organic chemical industry, 2, 4-dichlorofluorobenzene is used as a raw material, alkylation and reaction with tert-butyl nitrite are performed to generate oxime, and then hydrochloric acid hydrolysis is performed to generate 2, 4-dichloro-5-fluoroacetophenone and hydroxylamine hydrochloride; according to the method, co-production of the 2, 4-dichloro-5-fluoroacetophenone and the hydroxylamine hydrochloride is innovatively realized, not only are high yield and high purity of the target product 2, 4-dichloro-5-fluoroacetophenone ensured, but also the nitrogen element in the reaction is recycled and converted into the hydroxylamine hydrochloride with high additional value, and the atom economy is remarkably improved; according to the method, the operation process is greatly simplified, the use of dangerous reagents is avoided, and the intrinsic safety and environmental friendliness of the process are improved from the source; the method is simple to operate, safe and environment-friendly, the production cost is effectively reduced, and the market competitiveness of the product is enhanced.

The utility model discloses a filtering device for 3, 4-dihydroxybenzonitrile, which is suitable for decoloring and filtering a 3, 4-dihydroxybenzonitrile crude product solution by using a precision filter after the 3, 4-dihydroxybenzonitrile crude product solution is synthesized from materials such as hydroxylamine hydrochloride, methanol, vanillin, powdered activated carbon and the like, and a titanium filter element coated with a polytetrafluoroethylene film is arranged in the precision filter. The titanium filter element coated with the polytetrafluoroethylene film is a special device special for the 3, 4-dihydroxybenzonitrile through special design, a 3, 4-dihydroxybenzonitrile solution with high chromaticity and turbidity requirements can be obtained through the filtering device, and a 3, 4-dihydroxybenzonitrile product with high purity can be obtained through crystallization.

The invention provides a preparation method of acacia gum nano-composite hydrogel. The preparation method comprises the following steps: S1, mixing an acacia gum aqueous solution with a free radical initiator, and then sequentially adding acrylonitrile, CuFe2O4 nanoparticles and a cross-linking agent into the mixture to obtain the acacia gum nano composite hydrogel. The acacia gum nano-composite hydrogel combines the characteristics of a natural polymer, a synthetic polymer and inorganic nanoparticles, and is an effective adsorbent for removing heavy metals in an aqueous solution, the prepared magnetic hydrogel is treated by hydroxylamine hydrochloride, so that a nitrile group is converted into an amidoxime group to serve as a bidentate ligand, and the adsorption capacity of the hydrogel is improved. The existence of CuFe2O4 in the acacia gum nano-composite hydrogel makes the recoverable magnetic hydrogel possible, the recoverable magnetic hydrogel can be easily removed from an aqueous solution and regenerated, and after three continuous cycles, the recoverable magnetic hydrogel still has high heavy metal adsorption capacity.

The invention provides a synthesis method of a medical intermediate (3R, 5R)-3-Boc-amino-5-fluoropiperidine, which comprises the following steps: step S1, trans-4-hydroxy-D-proline methyl ester hydrochloride is used as a raw material, under the action of triethylamine, a reaction is carried out for 2-4 hours, and the reaction product is subjected to post-treatment to obtain the (3R, 5R)-3-Boc-amino-5-fluoropiperidine. Dichloromethane is used as a solvent to react with triphenylchloromethane to obtain (4S)-4-hydroxy-1-(triphenylmethyl)-D-proline methyl ester; s2, the (4S)-4-hydroxy-1-(triphenyl methyl)-D-proline methyl ester is subjected to oxidation, and 4-oxy-1-(triphenyl methyl)-D-proline methyl ester is obtained; s3, enabling the compound 4-oxo-1-(triphenyl methyl)-D-proline methyl ester to react with hydroxylamine hydrochloride, so as to obtain a compound hydroxylamino-1-(triphenyl methyl)-D-proline methyl ester; step S9, the compound (3R, 5R)-3-Boc amino-1-triphenyl-5-fluoropiperidine is subjected to Trt removal under the action of hydrochloric acid, and a compound (3R, 5R)-3-Boc amino-5-fluoropiperidine is obtained; according to the method disclosed by the invention, the (3R, 5R)-3-Boc amino-5-fluoropiperidine can be efficiently and economically synthesized by optimizing a reaction route.

The invention discloses a preparation method of a chiral intermediate (S)-3-methyl-1-tert-butoxycarbonyl-1,4-diazepane for treating ocular hypertension, relating to the technical field of pharmaceutical chemicals. The invention comprises the following steps: using 1-benzyl-3-methylpiperidin-4-one as a starting raw material, performing chiral resolution to obtain an intermediate 1, performing an addition-elimination reaction on the intermediate 1 and hydroxylamine hydrochloride to obtain an intermediate 2, performing a Beckmann rearrangement reaction on the intermediate 2 to obtain an intermediate 3, performing an amino deprotection reaction on the intermediate 3 to obtain an intermediate 4, performing an amino protection reaction on the intermediate 4 and di-tert-butyl dicarbonate to obtain an intermediate 5, and performing a decarbonylation reaction on the intermediate 5 to obtain the (S)-3-methyl-1-tert-butoxycarbonyl-1,4-diazepane. The preparation method has the characteristics of readily available raw materials, a simple process and a high product yield, and is suitable for the industrial production of the (S)-3-methyl-1-tert-butoxycarbonyl-1,4-diazepane.

The present invention belongs to the technical field of electrode materials and heavy metal wastewater treatment, and discloses a WS2 pseudocapacitor interface material, its preparation method and application. The preparation method comprises the following steps: uniformly dispersing sodium tungstate, thiourea, hydroxylamine hydrochloride and a surfactant in deionized water to obtain a mixed solution; heating the mixed solution to 160-200°C for hydrothermal reaction, separating, washing and drying the reaction product to obtain a WS2 pseudocapacitor interface material. The preparation method of the present invention is simple, the reaction conditions are mild and the cost is low. The obtained WS2 pseudocapacitor interface material can be used for capacitor adsorption to remove heavy metal ions, and has a great effect on Cr 3+ 、Cd 2+ , Pb 2+ 、Ni 2+ 、Co 2+ 、Cu 2+ The removal efficiency of heavy metal ions can reach over 90%. Compared with conventional methods, it has the advantages of high energy efficiency, environmental friendliness and no pollution.

The invention discloses a preparation method of salicylhydroxamic acid, and relates to the technical field of flotation reagents and preparation thereof, in particular to the preparation method of salicylhydroxamic acid, which comprises the following steps: in the presence of an organic solvent and water, adding a phase transfer catalyst, alkali and a hydroxylamine hydrochloride aqueous solution into a reaction tank, uniformly stirring, adding methyl salicylate, and reacting for 2-4 hours at the temperature of 50-60 DEG C; after the reaction is finished, concentrated sulfuric acid is added to obtain salicylhydroxamic acid, through the arrangement of the reaction tank, a stirring rod, an extrusion bag and a slope ring plate, the stirring rod can be driven by a driving column to rotate, and the downward moving-resetting circulation of the stirring rod is achieved through the cooperation of an adjusting rod, a top block and the slope ring plate; the extrusion bag is driven to press and grind sodium hydroxide particles gathered on the inner bottom surface of the reaction tank, particle aggregation is broken, the particles are refined, the sodium hydroxide dissolution rate is increased, local high temperature is prevented from damaging key components such as hydroxylamine and methyl salicylate, generation of non-target substances is reduced, and the yield and purity of salicylhydroxamic acid are improved.

The invention discloses a low-toxicity method for measuring soil nitrate nitrogen 15N based on an optical cavity ring-down technology, which comprises the following steps: extracting 1 g of fresh soil with 10 ml of 2M KCl, determining the content of nitrate nitrogen in the soil through a flow analyzer, and diluting to 0.14-0.28 mgN / ml to obtain a soil extract for later use; the method comprises the following steps: adding 2ml of a soil leaching solution into a headspace bottle for later use, and then sequentially adding 0.2 ml of a 0.01 M VCl3 solution and 0.5 ml of 0.02 M hydroxylamine hydrochloride; transferring to a constant-temperature shaking table at the temperature of 37 DEG C, reacting for 16 hours at the speed of 125 rpm / min, extracting a gas sample by using a gas-tight injector, and injecting into an isotope measuring instrument based on an optical cavity ring-down technology to measure 15N of N2O as 15N of nitrate nitrogen. According to the method, the analysis efficiency of the whole experiment can be effectively improved, environmental hazards caused by use of high-toxicity chemical reagents are reduced, and meanwhile, the analysis cost is effectively reduced.