200 results about "Paraformaldehyde" patented technology

The invention discloses a lignin-based epoxy anticorrosive paint and a preparation method thereof. The anticorrosive paint is prepared by mixing a lignin-based epoxy anticorrosive paint component, a lignin-based phenolic amine curing agent and a diluent. According to the lignin-based epoxy anticorrosive paint disclosed by the invention, on one hand, a lignin epoxy resin acetylation modification method based on lipase is introduced, and the content of hydrophilic groups is reduced, so that formation of a compact lignin cross-linked network structure is promoted, and the barrier ability, heat resistance and aging resistance of an anticorrosive coating on a chemical medium are improved on the resin level; on the other hand, lignin and furfural are respectively used for partially replacing phenol and paraformaldehyde to prepare a lignin-based phenolic aldehyde amine curing agent with high chemical inertness, so that the protection effect of a coating in an extreme corrosion environment and the adhesive force to a metal base material are improved on the curing agent level. The lignin-based epoxy anticorrosive paint prepared by the invention has good corrosion resistance, aging resistance, thixotropy and adhesive force.

The invention discloses a triazine desulfurizer and a preparation method thereof, and belongs to the technical field of gas purification. The triazine desulfurizer is mainly prepared from the following raw materials in percentage by weight: 20 to 50 weight percent of triazine derivative, 10 to 15 weight percent of sterically hindered amine, 3 to 7 weight percent of stabilizer, 1 to 3 weight percent of synergist, 0.5 to 1.5 weight percent of penetrant, 0.5 to 1.5 weight percent of inhibitor, 1 to 2 weight percent of additive and the balance of water, the preparation method of the triazine derivative comprises the following steps: adding 2-(diphenylphosphino) ethylamine into a toluene solvent, adding a paraformaldehyde aqueous solution in batches under a stirring condition, and reacting for 2-8 hours to obtain the triazine derivative. According to the triazine desulfurizer and the preparation method thereof provided by the invention, the triazine derivative and the sterically hindered amine are taken as a host, and the stabilizer, the synergist, the penetrant, the inhibitor and the assistant are compounded, so that the scaling trend of the triazine desulfurizer in an oil and gas well can be slowed down, the dissolution rate of hydrogen sulfide and the mass transfer rate in a solution are increased, and the desulfurization reaction is promoted; the desulfurization effect and the desulfurization rate are improved, and meanwhile, a very good scale inhibition effect is also achieved.

The invention discloses a strong acid and alkali resistant plastic material for fume hood surface decoration and a preparation method of the strong acid and alkali resistant plastic material, belongs to the technical field of plastic material processing, and aims at solving the technical problem that in the prior art, the acid and alkali resistance and the bending modulus of a plastic material for fume hood surface decoration need to be further improved. The preparation method specifically comprises the following steps: stirring amino-modified fluorosilicone resin, paraformaldehyde and 1, 4-dioxane in a reaction kettle, dropwise adding an anacardol solution, heating the reaction kettle to 85-95 DEG C, carrying out heat preservation reaction for 6-8 hours, and carrying out post-treatment to obtain the anacardol-based benzoxazine resin. Perfluoro-modified polysiloxane benzoxazine is prepared, naphthalene-containing epoxy resin and imidazole-modified silicon carbide microspheres are compounded, in-situ catalysis synergistic curing is carried out by using filler interface imidazole, a compact organic-inorganic hybrid interpenetrating network is constructed, and the strong acid and alkali corrosion resistance and bending modulus of the material are remarkably improved.

The invention discloses a phosphorus-nitrogen synergistic flame-retardant benzoxazine / epoxy resin composite material and a preparation method thereof. Firstly, a phenolic compound and DOPO react to generate an intermediate product, and then the intermediate product, an amine compound and paraformaldehyde are subjected to a dehydration condensation reaction to generate the phosphorus-nitrogen synergistic flame retardant benzoxazine. The phosphorus-nitrogen synergistic flame-retardant benzoxazine is added into epoxy resin for thermocuring to obtain the composite material. The prepared benzoxazine flame retardant contains phosphorus and nitrogen elements, the nitrogen-based flame retardant has the advantages of low pollution, low smoke, good compatibility with EP and the like, and a quenching effect, a dilution effect and a carbon layer barrier effect can be generated in the combustion process to prevent further combustion of flames. The composite material has better flame retardant property, can effectively reduce the risk of fire hazard caused by overheating or short circuit of equipment, and ensures the safe and stable operation of energy equipment.

The invention provides a method for preparing p-chloromethyl styrene, which comprises the following steps: (1) in the presence of a catalyst and an assistant, carrying out reaction on paraformaldehyde and hydrogen chloride to obtain a chloromethylation reagent; (2) reacting beta-halogenated ethyl benzene with the chloromethylation reagent obtained in the step (1) to obtain chloromethyl halogenated ethyl benzene; (3) adding an extracting agent into the chloromethyl halogenated ethylbenzene reaction liquid obtained in the step (2) for extraction to obtain an oil layer containing chloromethyl halogenated ethylbenzene and a water-containing acid layer, and crystallizing the oil layer to obtain purified p-chloromethyl halogenated ethylbenzene; and (4) in the presence of a solvent, carrying out elimination reaction on the purified p-chloromethyl halogenated ethyl benzene and alkali to obtain p-chloromethyl styrene.

The invention provides a fullerene pyrrolidine enantiomer mediated cholesteric liquid crystal with circular polarization luminescence property and nonlinear anti-saturated absorption property, and a preparation method and application thereof. The method comprises the following steps: dissolving C60, paraformaldehyde and (R / S)-(+ / -)-alpha-methylbenzylamine in an organic solvent, and carrying out heating reflux reaction to obtain fullerene pyrrolidine enantiomer molecules; dissolving in carbon disulfide to obtain an enantiomer solution; dissolving achiral dye molecules in a solvent to obtain a dye solution; and dropwise adding the enantiomer solution and the dye solution into thermotropic liquid crystal molecules, and drying to obtain the thermotropic liquid crystal. The method is simple, the obtained cholesteric liquid crystal system shows a characteristic fingerprint texture and has a periodic spiral structure, and the doping proportion of chiral molecules is easy to adjust; the composite system has good time stability and is not prone to phase separation; the liquid crystal platform shows good circular polarization luminescence performance and third-order nonlinear optical property, and is a cholesteric liquid crystal platform with an integrated function.

The invention relates to the field of pipes, and discloses a high-strength CPVC pipe and a preparation method thereof.The pipe comprises CPVC resin, modified multi-walled carbon nanotubes, modified nano silicon dioxide and auxiliaries; the modified multi-walled carbon nanotubes are prepared by grafting phosphorus-containing cardanol derivative based benzoxazine and oxidized multi-walled carbon nanotubes; phosphorus-containing cardanol derivative benzoxazine reacts with 1, 5-naphthylenediamine to prepare an aldehyde cardanol intermediate, the aldehyde cardanol intermediate is prepared by reacting paraformaldehyde with hydrogenated cardanol, the obtained cardanol derivative and DOPO are subjected to addition, and then the obtained phosphorus-containing cardanol derivative reacts with paraformaldehyde and 3-aminopropyltriethoxysilane to prepare the flame retardant. The modified nano silicon dioxide is prepared by introducing polyethylene glycol into the surface of isocyanated nano silicon dioxide and grafting with 3, 5-bis (tert-butyl)-4-hydroxybenzene propionyl chloride, and the pipe prepared by the invention is high in tensile strength and impact strength and has good long-acting oxidation resistance, high temperature resistance and flame retardance.

The invention relates to the technical field of catalytic synthesis, in particular to a chloromethylation catalyst, a preparation method of the chloromethylation catalyst and a method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene through the chloromethylation catalyst, and the chloromethylation catalyst is prepared by loading sulfonic acid compounds and (or) pyridine compounds and (or) copper salt on a molecular sieve. The method can improve the localization selectivity of chloromethylation. The method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene comprises the following steps of: reacting beta-bromophenylethane, paraformaldehyde and lewis acid in the presence of the chloromethylation catalyst to generate chloromethyl beta-bromophenylethane, and then performing elimination reaction under an alkaline condition to generate a chloromethyl styrene crude product; the high-purity ortho-position, meta-position and para-position chloromethyl styrene is obtained after the crude product is rectified, the brand-new catalyst is adopted in the method, the reaction selectivity is enhanced, the process is simple, and industrial production is facilitated.

The application provides a cell fixing solution for a myasthenia gravis antibody spectrum (IgG) detection kit (cellular immunofluorescence method) and a product and application thereof, and relates to the technical field of in-vitro detection. The cell fixing solution provided by the application is composed of polyoxymethylene, formaldehyde, acetic acid, raffinose and a buffer solution, can effectively fix the cell morphology, maximally retains the natural spatial conformation and antigen epitope integrity of myasthenia gravis related antigens AChR, Titin, RyR1, MuSK and LRP4, reduces the problems of antigen denaturation, epitope shielding and protein loss in the fixing process, can efficiently and accurately realize the synchronous joint detection of various specific antibodies, and the myasthenia gravis antibody spectrum (IgG) detection kit (cellular immunofluorescence method) prepared by the application has stable detection results, and has important clinical application value and industrial popularization prospect.

This invention provides a method for preparing and applying a highly insecticidal diamide compound, relating to the chemical and pesticide fields. The method includes: reacting 2-fluoro-3-nitrobenzoic acid with thionyl chloride (a chlorinating agent) and dimethylformamide (a catalyst) to obtain compound A; condensing compound A with 2-trifluoromethyl-4-heptafluoroisopropyl-6-bromoaniline amide to obtain compound B; reducing compound B to obtain compound C; and, during the reaction under a hydrogen atmosphere, determining the reaction temperature and hydrogen flow rate in each hydrogenation reaction zone based on the concentration of compound B; reacting compound C with paraformaldehyde to obtain compound D; chlorinating 3-chloro-4-fluorobenzoic acid with thionyl chloride (a chlorinating agent) and dimethylformamide (a catalyst) to obtain compound E; and amide condensing compound E with compound D to obtain the novel diamide compound of this invention. The diamide compound of this invention exhibits excellent insecticidal effects when used in pesticide compositions.

The invention discloses a synthesis method of 4-bromo-3-(ethoxymethyl) benzoic acid, which comprises the following steps: (1) activating carboxyl of p-bromobenzoic acid serving as a raw material in the presence of an organic anhydride activator, and then performing chloromethylation reaction with paraformaldehyde in the presence of a chlorine-containing Lewis acid catalyst to obtain 4-bromo-3-(ethoxymethyl) benzoic acid; after the reaction is completed, carrying out post-treatment to obtain an intermediate 4-bromo-3-(chloromethyl) benzoic acid; and (2) carrying out nucleophilic substitution reaction on the intermediate obtained in the step (1) in ethanol under the action of inorganic alkali to prepare the target product 4-bromo-3-(ethoxymethyl) benzoic acid. According to the invention, through one-pot activation and chloromethylation of p-bromobenzoic acid, concise, efficient and highly economical synthesis from cheap raw materials to the sparsentan key intermediate is realized.

The invention discloses a continuous production process of 1, 3-dimethyl-2-imidazolinone, and relates to the technical field of chemical processes, the process takes ethylene urea, formic acid, paraformaldehyde and water as raw materials, and the whole-process continuous production is realized through the steps of material preparation, batching, continuous reaction and post-treatment. The method is characterized in that water is used as a solvent, the reaction temperature is 150-250 DEG C, the pressure is 1-8 MPa, and the purity of the rectified product is greater than or equal to 99.5%. The method overcomes the defects of insufficient reaction and high cost of the existing intermittent process, has the advantages of high conversion rate, few impurities, few three wastes, easiness in automation and the like, and is suitable for industrial large-scale production.

The invention belongs to the technical field of synthesis of extraction agents, and particularly relates to a preparation method and application of amido diphosphinic acid. The preparation method comprises the following steps: (1) mixing a solvent, primary amine, cyclohexylphosphinic acid and inorganic acid, and heating until the solution is clear and transparent; (2) adding a formaldehyde solution or paraformaldehyde into the clear and transparent solution for reaction; and (3) removing a water phase from the mixture obtained after the reaction in the step (2) is finished, dissolving jelly obtained after the water phase is removed by using dichloromethane, and carrying out washing, rotary evaporation and drying to obtain the amido diphosphinic acid.

The invention discloses a hydrogen sulfide scavenger for acid fracturing and a preparation method thereof, and relates to the technical field of hydrogen sulfide scavengers, the hydrogen sulfide scavenger comprises the following raw materials by weight: 30-45 parts of an aldehyde compound, 30-45 parts of an alcohol amine compound, 10-18 parts of a diamine bridging agent, 2-6 parts of a solubilizing compounding agent, 20-30 parts of a solvent and 1-3 parts of a catalyst; the aldehyde compound is divided into a component A and a component B, the mass ratio of the component A to the component B is 2: 1-3: 1, the component A is paraformaldehyde, and the component B is at least one of glyoxal or glutaraldehyde. By optimizing a molecular skeleton and introducing a hydrophilic group, the sulfur removal capacity and chemical stability in a strong acid environment are improved, compatibility with acid liquor is good, generation of acid sludge and insoluble precipitates is effectively inhibited, secondary damage to a stratum is avoided, and the high efficiency and mass transfer performance of a product are guaranteed through the preparation process.

The application discloses a preparation method of energy storage long-cycle COPNA carbon material, and belongs to the technical field of lithium battery energy storage materials, and is characterized by comprising the following steps: first, composite carbonaceous raw materials are heated to 100 DEG C, and after being uniformly stirred, a compounded crosslinking agent and a compounded catalyst are added, and the stirring is continued for 10-15 min until the mixture is uniformly mixed, and then a crosslinking reaction is carried out at 120 DEG C-160 DEG C, and the reaction time is 4-6 h, so that COPNA resin is obtained; the obtained COPNA resin is carbonized at 460 DEG C-520 DEG C, so that COPNA carbon material is obtained. The application has the beneficial effects that: oil slurry pitch, coking wax oil and ethylene tar are used as the composite carbonaceous raw materials, the proportion of the three is controlled to accurately control the polarizing structure proportion of the COPNA carbon material, the structural stability of the material is improved, and the long-cycle requirement is adapted; the COPNA carbon material can consider the conductivity and the regularity of the layered orientation by using the furfural-polyformaldehyde compounded crosslinking agent and the compounded catalyst, and the structure damage or the conductivity decline in the long-term cycle process is avoided.

This invention discloses a method for preparing furanyl diisocyanate and its applications, relating to the field of organic polymer compounds. Under nitrogen atmosphere, furoic acid is added to concentrated sulfuric acid and mixed, followed by the addition of paraformaldehyde and a temperature-controlled reaction to obtain bis(5-formic acid-2-furan)methane. An organic base is added to a solvent containing bis(5-formic acid-2-furan)methane, and diphenyl azide phosphate is added dropwise to react and obtain bis(5-acyl azide-2-furan)methane. The bis(5-acyl azide-2-furan)methane is dissolved in an organic solvent and reacted to obtain furanyl diisocyanate. This invention provides a high-yield, high-selectivity one-step method for obtaining the intermediate bis(5-formic acid-2-furan)methane, shortening the synthetic route, improving synthetic efficiency, avoiding the use of sodium azide, increasing safety, and reducing production costs. The production of bio-based polyurethane is environmentally friendly, economical, and industrially applicable, and can be used to develop environmentally friendly coatings, adhesives, and sealants.

The invention discloses a hydroxymethyl phosphonate flame retardant and a preparation method and application thereof.The method comprises the steps that phosphorus trichloride and epoxide serve as starting raw materials and react in the presence of a catalyst to generate trichloro alkyl phosphite, the obtained triester structure is dropwise added into phosphorous acid, heat preservation reaction is conducted, and dichloro alkyl phosphite is obtained; and adding a catalyst 2 into the diester product, heating, slowly adding paraformaldehyde, and continuously reacting to obtain the hydroxymethyl phosphate flame retardant. The method is low in cost, mild in reaction condition, solvent-free, capable of being efficiently completed without extreme conditions, high in reaction speed and high in conversion efficiency, is compatible with existing chemical production equipment, and provides a solid foundation for large-scale industrial production.

The invention discloses application of jellyfish and snow rabbits in inhibition of ERK phosphorylation level and MAPK pathway and an evaluation method of the jellyfish and snow rabbits, and relates to the technical field of biological medicines.The method comprises the following steps that 1, a treated jellyfish and snow rabbits breast cancer cell group and a control breast cancer cell group are established; and step 2, respectively dividing the two groups of samples in the step 1 into two parts, fixing one part in paraformaldehyde with the mass concentration of 10%, treating, embedding in paraffin for immunohistochemical analysis, and quickly freezing the other part for transcriptomics analysis and the like. According to the invention, UPLC-MS is adopted to determine the main components of SMM, the influence of SMM on breast cancer (BC) is evaluated through in-vivo experiments, in order to deeply clarify the mechanism, network pharmacology and transcriptomics analysis are integrated, finally, immunohistochemistry (IHC) is adopted to verify and explore the exact breast cancer resisting mechanism of SMM, and a scientific basis is provided for potential clinical application of SMM.

The present application relates to the technical field of formaldehyde production, in particular to a polyoxymethylene recovery equipment for formaldehyde production and a use method thereof, which comprises a tank body, an inlet and outlet mechanism is arranged on the tank body, a feeding mechanism is arranged on the tank body, a stirring mechanism is arranged on the feeding mechanism, a transmission mechanism is arranged in the tank body, a temperature rising mechanism is arranged in the tank body, and a support seat is fixedly connected to the bottom of the tank body; through the feeding mechanism and the stirring mechanism, the corresponding lye can be added into the tank body in time, the polyoxymethylene is promoted to react to formaldehyde under the condition of strong alkali, and the reaction is more sufficient; through the transmission mechanism, the desalted water added into the tank body is stirred to accelerate the mixing; through the temperature rising mechanism, the polyoxymethylene particles deposited in the bottom of the tank body are heated, and the raw materials in the bottom of the tank body are further stirred and mixed, so that the deposition of polyoxymethylene is reduced.

The invention discloses a non-degreasing biological tissue dyeing method and device. The dyeing method of the non-degreasing biological tissue comprises the following steps: a sample fixing step: fixing a biological tissue sample by adopting paraformaldehyde and / or glutaraldehyde; and a dyeing step: carrying out electrophoresis dyeing on the fixed biological tissue sample which is not degreased by using a nucleic acid dye and a beta-amyloid protein small molecule dye. According to the non-degreasing biological tissue dyeing method disclosed by the invention, the non-degreasing biological tissue is directly dyed, so that the damage of degreasing operation to a sample is avoided; moreover, the nucleic acid dye is combined with the beta-amyloid protein small molecule dye, so that the whole brain sample can be quickly and efficiently dyed, and high-resolution fluorescence labeling and three-dimensional space distribution imaging of beta-amyloid protein plaques in the whole brain range can be realized; the method is of great significance in revealing the spatial distribution pattern of beta-amyloid protein and explaining the pathogenesis of Alzheimer's disease.

The invention discloses an alpha-dideuterium methylated sulfone compound as well as a synthesis method and application thereof, and belongs to the field of organic chemistry. In an air atmosphere, benzyl methyl sulfone and 2-((3, 5-dimethyl-4-methoxypyridine-2-yl) methylsulfonyl)-5-methoxy-1H-benzo [d] imidazole are used as substrates, in the presence of a catalyst [Cp * IrCl2] 2 and cesium carbonate, deuterated paraformaldehyde is used as a carbon source, sodium formate is used as an additive, and the alpha-dideuterium methylated sulfone compound is obtained through a reaction in an acetonitrile solvent at 120 DEG C. The reaction does not need to use a ligand and hydrogen, the reaction is simple and efficient, the potential value of the compound in medicinal chemistry is shown, and the compound has a certain inhibition effect on H3N2 subtype influenza viruses and has remarkable application potential.

The application provides a preparation method of 3,7-dinitro-1,3,5,7-tetraazabicyclononane, comprising the following steps: 1) feeding a first material comprising urea and concentrated sulfuric acid and a second material comprising fuming nitric acid and concentrated sulfuric acid into a microchannel reactor to perform a first-stage nitration reaction, to obtain a first-stage nitration reaction liquid; 2) feeding the first-stage nitration reaction liquid into a first tubular reactor to perform a second-stage nitration reaction, to obtain a second-stage nitration reaction liquid; 3) feeding the second-stage nitration reaction liquid and water into a second tubular reactor to perform a hydrolysis reaction, to obtain a hydrolysis liquid; 4) feeding the hydrolysis liquid and a third material comprising polyoxymethylene and ammonia water into a third tubular reactor to perform a condensation cyclization reaction, to obtain 3,7-dinitro-1,3,5,7-tetraazabicyclononane. The preparation method has the advantages of high safety, less waste pollution and simple operation.

This invention proposes a sperm staining kit based on a sequential staining strategy of tail pre-staining – rapid differentiation – enhanced nuclear staining. A gentle fixation with 4% paraformaldehyde and acetate buffer preserves the complete nucleic acid of the sperm head and the protein structure of the tail. The addition of PVP K30 and Tween-20 effectively inhibits non-specific adsorption and reduces staining background interference. Brilliant Green SF combined with sodium tartrate is used for specific staining of the sperm tail, followed by rapid differentiation to wash away non-specific staining. Nuclear staining is performed using toluidine blue O combined with sodium chloride and sodium tetraborate hydrate, specifically binding to DNA and enhancing color development stability, resulting in a blue sperm head and a light green tail with clear color contrast. This invention produces a clean staining background, accurately distinguishing the morphology of the sperm head, acrosome, and tail, significantly improving the accuracy of microscopic identification of abnormal sperm such as large-headed, small-headed, curled-tailed, broken-tailed, and short-tailed sperm. It is suitable for detecting sperm morphology and abnormality rates in breeding males.

The application belongs to the technical field of thermosetting resin materials, and provides a main chain type benzoxazine resin and a preparation method thereof.The preparation method comprises the following steps: adding a solvent, an allyl-containing bisphenol and paraformaldehyde into a reaction container, continuously adding indan diamine into the reaction container after temperature rising, reducing the temperature after temperature rising reaction, then adding or adding monobasic amine into the reaction container, continuously reacting after temperature rising after adding the monobasic amine, and distilling to obtain the main chain type benzoxazine resin after the reaction is completed.The preparation method uses the allyl-containing bisphenol and the indan diamine as the main chain, and uses the monobasic amine for end capping, so that the main chain type benzoxazine resin with the thermal performance and the dielectric performance is obtained.

The invention relates to the field of coatings, and discloses a high-temperature-resistant protective coating for an alloy surface and a preparation method of the high-temperature-resistant protective coating. The protective coating is prepared from waterborne epoxy resin, high-temperature-resistant filler, cardanol-based modified benzoxazine resin, a hyperbranched modifier, a curing agent and auxiliaries; according to the cardanol-based modified benzoxazine resin, paraformaldehyde is utilized to introduce an aldehyde group into a hydrogenated cardanol matrix to prepare a cardanol-based aldehyde-containing intermediate, then the cardanol-based aldehyde-containing intermediate reacts with 1, 5-naphthalene diamine, and then the cardanol-based aldehyde-containing intermediate reacts with gamma-aminopropyltriethoxysilane and paraformaldehyde through Mannich reaction to prepare the cardanol-based modified benzoxazine resin. The hyperbranched modifier is prepared by carrying out addition on 2, 4-dihydroxybenzophenone and isocyanatopropyltriethoxysilane, initiating hydrolytic condensation by utilizing a sol-gel method and then introducing triglycidyl isocyanurate to carry out a ring-opening reaction, and the protective coating prepared by the preparation method is strong in adhesive force, high in mechanical strength, good in wear resistance, good in wear resistance, good in wear resistance and good in wear resistance. Meanwhile, good corrosion resistance, high temperature resistance, ultraviolet aging resistance and flame retardance are achieved.

The invention relates to a method for preparing a hydroxyl naphthaldehyde derivative by using a cobalt complex, which comprises the following step: by taking naphthol and paraformaldehyde as raw materials and the cobalt complex containing an ortho-carborane benzothiazole structure as a catalyst, reacting at room temperature to synthesize the hydroxyl naphthaldehyde derivative. Compared with the prior art, the cobalt complex containing the ortho-carborane benzothiazole structure is applied to the reaction for catalytically synthesizing the hydroxyl naphthaldehyde derivative through the one-pot method, the use equivalent of the catalyst is low, the reaction condition is mild, the substrate universality is high, and the yield is high.

The invention relates to the technical field of organic synthesis, and provides a synthesis method of an important organic synthesis intermediate methyl diethyl phosphonate. Comprising the following steps: firstly, adding paraformaldehyde and alkali into a solvent, heating and stirring, and filtering to obtain an intermediate solution; and adding cation exchange resin and the intermediate solution into a reaction flask, dropwise adding diethyl phosphite, carrying out a heat preservation reaction after dropwise adding is completed, filtering to remove the cation exchange resin (which can be recycled for multiple times) after the reaction is completed, and carrying out reduced pressure distillation to remove the solvent and a trace amount of diethyl phosphite residue, so as to obtain the product. The method has the main advantage that paraformaldehyde is used as a methylation reagent and reacts with diethyl phosphite in one step under the action of a catalyst to obtain a target product.

The invention relates to the technical field of tromethamine synthesis, in particular to a continuous flow synthesis process of tromethamine. Comprising the following steps: adding nitromethane and a solvent A into a container A to obtain a solution A; adding a depolymerizing agent, a solvent B and paraformaldehyde into a container B to obtain a solution B; the first feeding pump and the second feeding pump respectively convey the solution A and the solution B to a micro-channel reactor at the same time for condensation reaction to obtain condensation reaction liquid; transferring the condensation reaction solution to an acidification kettle, and adding a quenching solution for reaction to obtain a quenching reaction solution; diluting the quenching reaction solution, adding a decolorizing agent, and filtering to obtain a decolorizing reaction solution; adding the decolorization reaction liquid and a solvent C into a hydrogenation reaction system by using a circulating pump, and carrying out hydrogenation reaction under the action of hydrogen and a catalyst to obtain hydrogenation reaction liquid; concentrating the hydrogenation reaction liquid to remove the solvent to obtain a tromethamine crude product, and refining the tromethamine crude product to obtain a tromethamine finished product. The method has the effects of low safety risk, continuous and smooth continuous flow pipeline and high product yield and purity.

This invention discloses the preparation of a high-efficiency paraformaldehyde sulfonic acid catalyst and its application in the catalytic synthesis of C14 secondary alcohols, relating to the field of olefin catalytic hydration technology. The catalyst is prepared by high-temperature polymerization of p-toluenesulfonic acid and paraformaldehyde under concentrated sulfuric acid catalysis. C14 olefins, the paraformaldehyde sulfonic acid catalyst, isopropanol, and deionized water are added to a reactor, and a catalytic reaction is carried out at a certain temperature. The product conversion rate is 0.46%, and the selectivity is >99%. The catalyst of this invention is simple to prepare, has a well-developed mesoporous structure and sufficient acidic sites, provides mild catalytic hydration reaction conditions, exhibits good olefin conversion and secondary alcohol selectivity, and is easily recoverable and reusable. The process is green and environmentally friendly, with high atom economy, and is beneficial for the industrial conversion and application of high-value utilization of Fischer-Tropsch olefins from coal-to-oil.

The invention relates to the technical field of preparation of fluorine-containing intermediates, and discloses a synthesis method for preparing 4, 4 '-difluorobenzophenone through a one-pot domino reaction. The invention aims to solve the problems of expensive raw materials, complex process, serious pollution, low yield and purity and the like in the prior art. According to the method, 4-fluorobenzoic acid and fluorobenzene are taken as raw materials, any one or more of trifluoromethanesulfonic anhydride, phosphorus pentoxide, trifluoroacetic anhydride or paraformaldehyde is taken as an acid catalyst under a solvent-free condition, and a target product is directly prepared through a one-pot reaction. After the reaction is finished, excessive fluorobenzene is recovered, a high-purity product is obtained through extraction, alkali washing, drying and concentration, and unreacted 4-fluorobenzoic acid can be recovered by acidifying a water phase. The method has the advantages of simple process, easily available raw materials, mild conditions and environmental protection, realizes the excellent effects that the conversion rate of 4-fluorobenzoic acid is greater than 99%, the product yield is greater than 95% and the purity is greater than 99%, and is suitable for industrial production.