23 results about "Methylhydrazine" patented technology

The present application relates to a kind of preparation method of trifluoromethyl pyrazole compound, belong to the technical field of organic synthesis.The specific method is: (1) trifluoroacetyl ethyl acetate is first with hydrazine hydrate cyclization reaction and generates compound of formula III;(2) under the catalysis of base, compound of formula III is reacted with difluoromethylation reagent and generates compound of formula II;(3) compound of formula II is reacted with methylating agent and obtains compound of formula I;The difluoromethylation reagent is difluoro-monochloromethane or sodium difluoro-monochloroacetate;The methylating agent is chloromethane, bromomethane, iodomethane, dimethyl sulfate or dimethyl carbonate.The present application is prepared by changing reaction route, and the higher-priced raw material methylhydrazine is replaced, and isomer impurity is no longer generated in the product prepared.Not only raw material cost is reduced, but also the purity of product is improved.

The invention discloses a pyrimidine derivative containing a thiosemicarbazide structure and application of the pyrimidine derivative, and relates to the technical field of medicines, the compound has good oxidation resistance and alpha-glucosidase resistance activity, and the compound is 2-(4, 4 '-difluorophenyl)-2-(4, 4'-difluorophenyl)-2-(4, 4 '-difluorophenyl)-2-(4, 4' The IC50 values of the compound 2-(4, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1-methylsulfamide on DPPH (1, 1-diphenyl-2-picrylhydrazyl) scavenging activity and ABTS (2, 2, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1-methylsulfamide are 3.96 mu g / mL and 2.01 mu g / mL respectively, the IC50 value of the compound 2-(4, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1-methylsulfamide on alpha-glucosidase inhibitory activity is 38.62 mu g / mL, the effect is best, and the compound 2-(4, 6-dimethyl pyrimidine-2-yl)-N-methylhydrazine-1 The pyrimidine derivative containing the thiosemicarbazide structure has a general formula shown in the specification, and is superior to control medicaments such as vitamin C, vitamin E and acarbose.

This invention belongs to the field of compound synthesis, specifically relating to a method for synthesizing 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid. The invention involves a condensation reaction of difluoroacetaldehyde half-ethanol and cyanoacetaldehyde under a catalyst; the resulting intermediate is then washed with water and reacted directly with hydrazine hydrate to obtain an intermediate product. Finally, the intermediate product is reacted with formaldehyde under a catalyst to undergo cyclization and aromatization, followed by hydrolysis to the final product. This invention provides a novel method for synthesizing 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, using difluoroacetaldehyde half-ethanol as the fluorinating agent in the reaction process, resulting in a simple synthesis method. This invention is the first to use the less expensive hydrazine hydrate instead of methylhydrazine to synthesize 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, resulting in lower cost, simpler operation, and less waste generation, thus possessing higher economic and environmental value and being more suitable for industrial production.

The present application relates to the technical fields of reaction kettle, and discloses a reaction kettle for preparing methylhydrazine aqueous solution, which comprises a reaction kettle, a rotating shaft arranged in the reaction kettle, an end cover arranged at the top end of the reaction kettle, a stirring frame arranged on the rotating shaft, the stirring frame comprising an upper cross beam, a lower cross beam and a connecting rod, the two ends of the connecting rod being connected with the upper cross beam and the lower cross beam respectively, a conveying belt arranged on the stirring frame, the conveying belt being rotatably arranged on the stirring frame, a first driving mechanism arranged on the stirring frame and used for driving the conveying belt to rotate, a discharge chute arranged on the side wall of the rotating shaft, the side of the conveying belt being abutted against the side wall of the discharge chute, the other side of the conveying belt having a gap with the side wall of the discharge chute, the rotating shaft being a hollow shaft, a screw blade being arranged in the rotating shaft, a liquid passage being arranged on the rotating shaft close to the bottom of the reaction kettle, and a discharge port being arranged at the bottom end of the reaction kettle; the reaction kettle for preparing methylhydrazine aqueous solution can separate the catalyst from the liquid after reaction.

The invention relates to the field of preparation of fluxapyroxad, and discloses a preparation method of fluxapyroxad. The preparation method comprises the following steps: 1, heating 4, 4-difluoro-3-oxobutanamide and triethyl orthoformate in an organic solvent for reaction to obtain a compound a; 2, adding the compound a into a mixed solution of methylhydrazine and an organic solvent under an ice bath condition, and then reacting under a heating condition; and after the reaction is completed, evaporating out the solvent and concentrating to obtain a compound b. 3, under the action of an alkaline reagent and a metal catalyst, adding the compound b and 2-bromochlorobenzene into an organic solvent, and heating for condensation reaction to generate a compound c; and 4, adding the compound c and 3, 4, 5-trifluorophenylboronic acid into a solvent to carry out Suzuki reaction under the protection of nitrogen and the action of an alkaline reagent and a metal catalyst. And after the reaction is completed, evaporating out the solvent and concentrating to obtain the fluxapyroxad. The method disclosed by the invention has the characteristics of overall economy, environmental protection, safety and high efficiency, and also has relatively strong industrial application potential.

The invention provides a method for preparing 1-methyl-3-difluoromethyl-1H-pyrazole-4-carboxylic acid with high selectivity, which comprises the following steps: reacting methylhydrazine with a protective agent in an inert solvent to obtain single-protection methylhydrazine (IV); in the presence of alkali, carrying out condensation reaction on the single protection methylhydrazine (IV) and 2-ethoxymethylene-4, 4-difluoro-3-oxobutyric acid ethyl ester (I) to obtain an intermediate (V); adding acid into the reaction system obtained in the step S2 to synchronously remove the protecting group R and form a pyrazole ring, so as to obtain 1-methyl-3-difluoromethyl-1H-pyrazole-4-ethyl formate (II); alkali is added into the 1-methyl-3-difluoromethyl-1H-pyrazole-4-ethyl formate (II) for hydrolysis, then the hydrolysis product is acidified with acid, and suction filtration is performed to obtain the 1-methyl-3-difluoromethyl-1H-pyrazole-4-carboxylic acid (III). The content of regioisomers in the prepared product is less than or equal to 1%, the HPLC purity of the product is more than or equal to 98.0%, the content of single impurities is less than or equal to 0.15%, the moisture content is less than or equal to 0.1%, the residual acid content is less than or equal to 50 ppm, and the downstream reaction requirement can be met without secondary refining.

The invention discloses a methylhydrazine continuous flow synthesis process based on coupling of a microchannel reactor and a tubular reactor, and relates to the technical field of chemical engineering. The method comprises the following steps: by taking hydrazine hydrate, hydrochloric acid and methanol as raw materials, continuously introducing the raw materials into a micro-channel reactor through a metering pump to realize rapid mixing, preheating and preliminary methylation reaction so as to generate a reactant flow containing methylhydrazine hydrochloride; introducing the material flow into a series tubular reactor, carrying out constant-temperature and constant-pressure curing reaction, and prolonging the retention time so as to improve the conversion rate; and carrying out continuous dissociation and rectification separation to obtain a high-purity methylhydrazine product. The process overcomes potential safety hazards and efficiency limitation of traditional intermittent kettle reaction, enhances heat and mass transfer, improves reaction controllability and industrial applicability, and is suitable for continuous production of high-heat-release and high-risk methylation reaction.

The invention relates to a method for industrial production of 1-methyl-5-hydroxypyrazole. The method comprises the following steps: taking methyl 3-methoxyacrylate and methylhydrazine as raw materials, taking organic alkali as an acid-binding agent, desolventizing after reaction, and recrystallizing by using a proper solvent to obtain the high-purity 1-methyl-5-hydroxypyrazole. The method has the advantages that excessive methylhydrazine, high-temperature reaction and generation of isomers and tar are avoided, meanwhile, crystallization conditions of 1-methyl-5-hydroxypyrazole are developed, and the obtained product is good in solid character and quantitative in purity gt; the content is 99.5%. The technology has the advantages of simple three-waste treatment and high yield, can obtain high-purity 1-methyl-5-hydroxypyrazole, and has great industrial value.

The application provides a monomethylhydrazine production process and device, relates to the monomethylhydrazine production technical field, and comprises a salting kettle, a reaction kettle, a methanol distillation kettle, a rectification kettle and a refining distillation kettle, two groups of symmetrically-distributed U-shaped heat medium pipes and U-shaped cold medium pipes are welded through the circumferential wall of the tank body, and an arc-shaped spacing space is formed between each group of U-shaped heat medium pipes and U-shaped cold medium pipes and the inner circumferential wall of the tank body; four circumferentially-distributed pump cylinders are fixedly installed on the inner circumferential wall of the tank body, a water spraying ball is integrally formed at the bottom end of the vertical guide pipe, the water spraying ball is a hollow structure, a plurality of water spraying grooves are uniformly distributed on the spherical sidewall of the water spraying ball, and the water spraying ball and the vertical guide pipe are located in the arc-shaped spacing space; a bottom end portion of the vertical transmission shaft is fixedly sleeved with an impeller, and the impeller is located in the pump cylinder. The application can eliminate the restriction of the U-shaped heat medium pipes and the U-shaped cold medium pipes on the stirring effect of the chemical materials in the arc-shaped spacing space, and promote the overall uniform stirring of all chemical materials in the salting kettle and the reaction rate.

This invention discloses a continuous method for preparing 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid based on a cascaded process of cyclization-de-alcoholization-scraped membrane fluorination, belonging to the field of continuous synthesis technology in fine chemicals. The method includes: cyclizing ethyl 2-ethoxymethylene-4,4-dichloroacetoacetate with methylhydrazine in a loop reactor with forced external circulation, controlling the circulation ratio boundary at 15:1 to 18:1 to improve the selectivity of the target isomer; continuously removing at least some ethanol from the cyclized liquid and adding sulfolane for solvent replacement, ensuring that the ethanol content in the system before entering the fluorination stage is no higher than 1.0% (wt) and the water content is 0.1-0.2% (wt); subsequently, the resulting intermediate material, along with anhydrous potassium fluoride and 18-crown-6 to form a heterogeneous slurry, is fed into a vertical scraped membrane reactor, with a residence time strictly controlled at 169-171°C for 80-100 seconds, and rapid cooling within 3 seconds after discharge; finally, the target product is obtained through hydrolysis and acidification. This specific combined process can achieve high 1,3-isomer selectivity, high fluorination conversion, low aldehyde byproduct levels, and good long-term continuous operation stability without separating the cyclization intermediate.

The invention relates to the technical field of reaction kettles, and particularly discloses a reaction kettle for preparing a methylhydrazine aqueous solution, which comprises a reaction kettle, a rotating shaft arranged in the reaction kettle, an end cover arranged at the top end of the reaction kettle, a stirring frame arranged on the rotating shaft, the stirring frame comprises an upper cross beam, a lower cross beam and a connecting rod, and two ends of the connecting rod are respectively connected with the upper cross beam and the lower cross beam. A conveying belt is arranged on the stirring frame and rotationally matched with the stirring frame, a first driving mechanism is arranged on the stirring frame and used for driving the conveying belt to rotate, a discharging groove is formed in the side wall of the rotating shaft, one side of the conveying belt abuts against the side wall of the discharging groove, a gap is formed between the other side of the conveying belt and the side wall of the discharging groove, and the rotating shaft is a hollow shaft. A liquid through hole is formed in the rotating shaft close to the bottom of the reaction kettle, and a discharge hole is formed in the bottom end of the reaction kettle; the reaction kettle for preparing the methylhydrazine aqueous solution can separate a catalyst from reacted liquid.

The invention discloses a continuous catalysis system and method for synthesizing methylhydrazine, and relates to the technical field of methylhydrazine synthesis. Comprising the following steps: mixing hydrazine hydrochloride with pure water, heating in a water bath, and stirring until solids are completely dissolved to form a clear and transparent solution to obtain a methanol catalytic solution; the hydrazine hydrochloride raw material liquid and the methanol catalytic liquid are synchronously conveyed to a continuous reaction device with a microchannel connected with a subsequent reaction section in series, and a continuous catalytic alkylation reaction is completed; the method comprises the following steps: removing methanol from reaction discharge liquid through normal-pressure distillation, recovering, adding caustic soda liquid into residual liquid, stirring, standing for layering, taking an organic phase, carrying out reduced-pressure rectification, collecting a target fraction to obtain a methylhydrazine product, and carrying out gradient heating and precise pressure regulating technologies to realize stable control of reaction pressure. The small-volume continuous flow design is used for replacing the traditional large-volume intermittent kettle reaction, so that the core problems of prominent high-pressure risk and high danger coefficient of the traditional process are solved, and the intrinsic safety level of methylhydrazine synthesis is improved.

The invention discloses a preparation method of fluxapyroxad, aiming at the defects of high raw material cost and low yield in the existing process method, raw materials and intermediates required by reaction are prepared autonomously, and the yield of the intermediates is further improved by using a catalyst p-toluenesulfonic acid in the synthesis of 2-(ethoxymethylene)-4, 4-difluoro-3-oxobutyric acid ethyl ester. In the cyclization reaction of 2-(ethoxymethylene)-4, 4-difluoro-3-oxobutyric acid ethyl ester and methylhydrazine, the reaction system is optimized, so that the generation of an isomer is avoided, and the yield and the selectivity of the 3-difluoromethyl-1-methyl-pyrazole-4-carboxylic acid are remarkably improved.

The application belongs to the technical field of organic synthesis, and provides a preparation method and production equipment of 1,6-hexamethylene-bis(N,N-dimethylamino urea). Hexamethylene diisocyanate and methylhydrazine are gasified, and the hexamethylene diisocyanate gas and the methylhydrazine gas pass through the membrane layer into the reaction solvent to contact and perform nucleophilic addition reaction. The application adjusts the pore diameter of the hexamethylene diisocyanate gas, the methylhydrazine gas and the membrane layer, controls the amount of the hexamethylene diisocyanate gas and the methylhydrazine gas into the reaction solvent, and then controls the speed and process of the nucleophilic addition reaction, so that the nucleophilic addition reaction is more complete. The product is less wrapped around the raw material, the product has less impurities, the problem of sticky material difficult to centrifuge caused by excessive hexamethylene diisocyanate or insufficient methylhydrazine is avoided, the synthesized yellowing inhibitor has high purity, and the yellowing inhibitor purity is greater than or equal to 98.2%.

The application provides a preparation method and application of a high-nitrogen compound HZT and a high-energy-density mixed fuel; the application takes sodium azotetrazolate pentahydrate and monohydrochloric hydrazine as raw materials, and through heating reaction, low-temperature crystallization, recrystallization purification and low-temperature vacuum dehydration, anhydrous azotetrazolate dihydrazine salt (HZT) is prepared; the method has the advantages of safe and non-toxic raw materials, simple process, higher yield and purity, and solves the problems of existing synthesis routes, such as danger, toxic raw materials, and difficulty in industrialization. The obtained anhydrous HZT is dissolved in hydrazine, monomethylhydrazine or unsymmetrical dimethylhydrazine to prepare a stable and transparent high-energy-density mixed fuel, which can significantly improve the fuel density and the specific impulse of propellant density, and simultaneously reduce the freezing point of the fuel, and has excellent compatibility with conventional oxidizing agents (nitric acid, N2O4 and liquid oxygen). The HZT and the mixed fuel prepared by the application have outstanding energy performance, good compatibility and green and safe preparation, and are suitable for normal-temperature binary liquid propellants, and effectively break through the problem of improving the energy density of existing propellants.

The utility model belongs to the technical field of chemical equipment, and particularly relates to a hydrazine hydrochloride and hydrazine hydrate recovery device and methylhydrazine production equipment, which comprise a film evaporator, a discharge pipe at the bottom end of the film evaporator is connected with a hydrazine hydrochloride purification tank, and a two-stage serial condenser is connected behind an air outlet pipe at the upper part of one side of the film evaporator. The bottom end of the first-stage condenser is connected with a hydrazine hydrate recovery tank, an air outlet pipe of the first-stage condenser is in butt joint with an air inlet pipe of the second-stage condenser, and the bottom end of the second-stage condenser is connected with a mixture collection tank. According to the device, hydrazine hydrochloride and hydrazine hydrate can be purified more accurately, the requirement of secondary purification is reduced, a high-quality mechanically-applied raw material is provided for production of methylhydrazine, the production cost is remarkably reduced, meanwhile, the stability and the safety of a gas-liquid separation process are ensured, and the quality and the recovery efficiency of a product are further improved.

The invention provides an n-type 4H-SiC epitaxial growth control method and device, electronic equipment and a storage medium, and relates to the technical field of semiconductor material epitaxial growth. The method comprises the following steps: in an epitaxial layer growth stage, taking out methylhydrazine molecules in methylhydrazine liquid pre-stored in a doping source input part through hydrogen, and inputting the methylhydrazine molecules into a reaction chamber, so that methylhydrazine is used as an n-type doping source to grow an epitaxial layer on a substrate. The method aims at solving the problems that in the prior art, when nitrogen is adopted as an n-type doping source, the doping concentration consistency is poor, and when ammonia is adopted as the n-type doping source, a gas path system is complex, the equipment cost is high, the operation and maintenance difficulty is large, and the pollution risk is possibly introduced. According to the invention, methylhydrazine is adopted as the doping source, so that a gas path can be simplified, the doping concentration can be accurately regulated and controlled, and meanwhile, the residual nitrogen element in the growth environment can be reduced, thereby effectively reducing the fluctuation of the nitrogen element concentration in the epitaxial layer, and further realizing stable doping.

The application provides an n-type 4H-SiC epitaxial growth control method and device, electronic equipment and storage medium, and relates to the technical field of semiconductor material epitaxial growth. The steps of the method comprise: in the epitaxial layer growth stage, methylhydrazine molecules in the methylhydrazine liquid stored in the doping source input part in advance are taken out and input into the reaction chamber by hydrogen, so that the methylhydrazine grows the epitaxial layer on the substrate as an n-type doping source. The method aims to solve the problems in the prior art that when nitrogen is used as an n-type doping source, the doping concentration consistency is poor, and when ammonia is used as an n-type doping source, the gas path system is complex, the equipment cost is high, the operation and maintenance are difficult, and the pollution risk may be introduced. The application uses methylhydrazine as a doping source to simplify the gas path and accurately control the doping concentration, and at the same time, the residual of nitrogen elements in the growth environment can be reduced, thereby effectively reducing the fluctuation of the nitrogen element concentration in the epitaxial layer, and stable doping is realized.

The application discloses a hydrazide derivative-based carbon dot and a preparation method and application thereof, relates to the technical field of antibacterial materials, and discloses a preparation method, which comprises the following steps: taking a hydrazide derivative as raw material, and preparing a hydrazide derivative-based carbon dot through a one-step hydrothermal method; the hydrazide derivative is at least one of phenylhydrazine, methylhydrazine, isophthalic dihydrazide, thio-diacid hydrazide, salicylic hydrazide, acetic hydrazide, 3-pyridine carbohydrazide, benzhydrazine, p-carboxyphenylhydrazine and carbon hydrazide; the application also protects the hydrazide derivative-based carbon dot prepared through the above method and the application of the hydrazide derivative-based carbon dot in the preparation of antibacterial materials and antibacterial drug resistance materials. The application has the beneficial effect that 10 kinds of hydrazide derivative-based carbon dots are prepared through a simple one-step hydrothermal method with 10 kinds of hydrazide derivatives as precursors; the 10 kinds of hydrazide derivative-based carbon dots all have antibacterial activity, and the carbon hydrazide-based carbon dot shows excellent antibacterial activity and can effectively eradicate biofilms.

The application belongs to the field of pharmaceutical chemical industry, and particularly relates to a production method of a key intermediate of alamorelin, i.e. trimethylhydrazine hydrochloride. The technical scheme of the application comprises the following steps: step 1. synthesis of compound 2 is divided into two stages: stage 1. under the action of an alkali, hydrazine formic acid tert-butyl ester is reacted with a methylating agent to generate a mixture of compound 3 and compound 2. The mixture does not need to be further purified and separated, and is directly used in the second stage; stage 2. the mixture in the above step is further reacted with the methylating agent to be completely converted into compound 2, and step 2. compound 2 is removed from Boc protection in the presence of hydrochloric acid, and is salified to obtain trimethylhydrazine hydrochloride. The application provides a preparation method of trimethylhydrazine hydrochloride suitable for industrial production, and solves the problems of high production cost and safety hazards existing in the prior art.

This invention discloses a method for preparing 1-methyl-3-trifluoromethyl-5-hydroxypyrazole and its pesticide application, providing a method for preparing 1-methyl-3-trifluoromethyl-5-hydroxypyrazole (II) from 1-methyl-3-trichloromethyl-5-hydroxypyrazole (I) under normal pressure. The process is as follows: 40% methylhydrazine and ethyl trichloroacetoacetate are added dropwise to glacial acetic acid at 40±3℃, and the temperature is maintained at 40±3℃ before being raised to 90-100℃ and maintained thereafter. The endpoint is set by HPLC detection of a residual ester content of ≤1.0%. Acetic acid is recovered under reduced pressure, water is added twice, and solvent removal continues. Crystallization is performed at 0-15℃ to obtain I. Subsequently, 0.8-1.5 equivalents of hydrofluoric acid are added dropwise to toluene / triethylamine at 70-80℃ for 1-2 hours, and the temperature is maintained for 3-5 hours until the residual I content is ≤1.0% to obtain II. Preferred conditions are a two-stage constant-rate addition at 72-76℃ using Et3N·nHF (n=3-5). This method is simple, has controllable EHS (Environment, Health, and Safety), and allows for solvent recovery, making it suitable for industrial application. It can be used to synthesize pre-emergence herbicides such as sulfonylpyrazine.

The invention belongs to the technical field of biological medicines, and particularly relates to a 2-phenyl methylene hydrazine-1-amino sulfamide derivative as well as a preparation method and application of the 2-phenyl methylene hydrazine-1-amino sulfamide derivative. The antitumor cell proliferation activity of the compound is evaluated through an MTT method cancer cell proliferation inhibition experiment, and experimental data shows that the compounds with the structures as shown in the formulas I and II have definite and high antitumor cell proliferation activity, and can be used for preparing antitumor drugs. The conclusion proves that the 2-phenyl methylene hydrazine-1-sulfanilamide derivatives with the structures shown in the formula I and the formula II can be used for preparing the anti-tumor drugs and have application prospects in the anti-tumor aspect.

The hydrazine-containing composition is a liquid mixture that includes from 5 mol % to 95 mol % of unprotonated hydrazine selected from hydrazine, monomethylhydrazine, dimethylhydrazine, ethylhydrazine, and combinations thereof, and from 5 mol % to 90 mol % of at least one oxygen-containing solute or solvent selected from acetals, acetyls, alcoxyamines having two or more carbon atoms, aldehydes, amides, amides and particularly carboxamides, aminoalcohols, carbazides, semicarbazides, carbon-containing nitrate salts comprising cations with logarithmic dissociation constants less than 9.2, hydroxyalkyl nitro compounds, hydroxyalkylhydrazines, carbonates, carboxylic acids and anhydrides of carboxylic acids, esters, ethers, ketals, ketones, mono- and poly-alcohols in 31% or greater mass fraction, nitrate esters, nitrosamines, sugars, and combinations thereof. The unprotonated hydrazine has a first vapor pressure and the oxygen-containing solvent has a second vapor pressure that is less than the first vapor pressure.