579 results about "Phase-transfer catalyst" patented technology

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 3, 4 '-diaminodiphenyl ether.The preparation method comprises the steps that m-dinitrobenzene is dissolved with alcohol, and selective hydrogenation is conducted in a high-temperature and high-pressure reaction kettle with a palladium catalyst; and co-heating and refluxing the product after selective hydrogenation, a strong alkali aqueous solution, a first solvent and a phase transfer catalyst to obtain the m-aminophenol salt. M-aminophenol salt, p-nitroiodobenzene, alkali and a second solvent are subjected to a co-heating reaction, and then 3-amino-4 '-nitrodiphenyl ether is obtained through post-treatment; the method comprises the following steps: dissolving 3-amino-4 '-nitrodiphenyl ether with alcohol, carrying out hydrogenation reduction with a palladium catalyst, and carrying out post-treatment purification to obtain 3, 4'-diaminodiphenyl ether. According to the method, common m-dinitrobenzene is used as a raw material, m-nitroaniline is obtained through selective hydrogenation, m-aminophenol salt is prepared through the m-nitroaniline, then etherification reaction is carried out, the reaction yield is higher, the purity is better, and side reactions are few.

The invention discloses coal tar mixed phenol novolac epoxy resin as well as a preparation method and application thereof. The preparation method of the coal tar mixed phenol novolac epoxy resin comprises the following steps: S1, in an inert atmosphere, mixing and stirring refined coal tar mixed phenol, a solvent and an acid catalyst, then adding an aldehyde solution, and reacting to obtain phenolic resin; s2, in an inert atmosphere, mixing and stirring phenolic resin, a phase transfer catalyst and epoxy chloropropane, preheating to 70-100 DEG C, reacting for 1-4 hours, cooling to 65-70 DEG C, dropwise adding a basic catalyst, heating to 80-85 DEG C, continuously reacting for 2-3 hours, and naturally cooling; and carrying out post-treatment. According to the preparation method and application of the coal tar mixed phenol novolac epoxy resin, operation is easy and convenient, control is easy, and batch production can be achieved conveniently; in addition, the refined coal tar mixed phenol is low in price, the production cost of the anticorrosive paint is greatly reduced, the performance of the paint is improved, and the economic benefits of enterprises are improved.

The invention discloses cardanol basic characteristic mechanical enhanced flame-retardant epoxy resin containing aliphatic amine and a preparation method of the cardanol basic characteristic mechanical enhanced flame-retardant epoxy resin, and belongs to the technical field of flame retardance. The preparation method comprises the following steps: introducing an aldehyde group on a benzene ring of cardanol, and reacting with diamine to form an epoxy resin precursor substance; the preparation method comprises the following steps: fully mixing an epoxy resin precursor substance, epoxy chloropropane, a phase transfer catalyst and an alkaline substance for reaction to obtain cardanol basic intrinsic flame-retardant and mechanically-reinforced epoxy resin; the problems that raw materials of traditional bisphenol A type epoxy resin are non-renewable, the brittleness is large due to the molecular structure, flammability is caused, and the flame retardant property and the mechanical property cannot be considered at the same time are solved, biomass cardanol which is wide in source and low in cost is used as the raw material, and flexibility of an aliphatic chain and rigidity of aromatic hydrocarbon are combined; the Schiff base structure improves the flame-retardant efficiency of the matrix and also improves the mechanical properties of the matrix; the cured epoxy resin system has excellent thermal stability, flame retardance and mechanical properties, and has excellent popularization and application prospects.

The invention belongs to the field of preparation of ether substances, and particularly relates to a preparation method of perfluoro-2-alkoxy propionyl fluoride and perfluoroalkyl vinyl ether. The preparation method of the perfluoro-2-alkoxy propionyl fluoride comprises the following steps: carrying out addition reaction on acyl fluoride and hexafluoropropylene oxide in a polar aprotic solvent in the presence of an organic base catalyst, a phase transfer catalyst and a phase transfer cosolvent to prepare the perfluoro-2-alkoxy propionyl fluoride, the phase transfer cosolvent is selected from a hexafluoropropylene dipolymer, a hexafluoropropylene tripolymer or 1, 3-bis (trifluoromethyl) benzene. The method provided by the invention can effectively reduce the generation of HFPO polymer by-products, thereby improving the yield of the target product.

The invention discloses a phase transfer catalyst of metal ion complexing crown ether for efficiently preparing aquacide dichloride and application of the phase transfer catalyst. The catalyst is prepared by taking crown ethers as 18-crown-6 and dicyclohexyl-18-crown-6 ether and complex ions as lewis acid active components such as potassium ions, lithium ions, cobalt ions, copper ions and the like through a direct chemical method. The catalyst synergistically catalyzes a nucleophilic substitution reaction of a pyridine derivative and alkyl halide in an aprotic polar solvent such as acetonitrile or nitrobenzene, and synthesis of diquat dichloride can be realized under the conditions of 60-140 DEG C, normal pressure and no oxygen. The mass ratio of the pyridine derivative to the catalyst to the solvent in a reaction system is 1: (0.001-0.05): (5-8), and real-time monitoring and regulation are performed through an online infrared spectrum, a liquid chromatograph and a gas chromatograph-mass spectrometer. The purity of the product is more than 99% after the product is subjected to filtration, recrystallization with an ethanol-water mixed solvent and vacuum drying. The catalyst provided by the invention has the characteristics of high activity, strong stability and recoverability, obviously improves the atom economy of the reaction, simplifies the production process, reduces the energy consumption and pollution, and is suitable for large-scale industrial production.

A method for preparing 1,2-propanediol involves reacting propene with hydrogen peroxide in the presence of a catalyst mixture containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The process then involves separating the reaction mixture into an aqueous phase (Pa) containing 1,2-propanediol and an organic phase (Po); recycling at least part of the separated organic phase (Po) to the reaction; and recovering 1,2 propanediol from the separated aqueous phase (Pa). In the recovery, 1,2-propanediol is separated from the aqueous phase (Pa) by distillation and the apparent pH of the separated aqueous phase (Pa) is adjusted to at least 9 prior to the distillation to reduce the content of formic acid and acetic acid in the recovered 1,2-propanediol.

The invention relates to a preparation method of propargyl alcohol, and belongs to the technical field of organic chemistry. The reaction formula is as follows: # imgabs0 #; comprising the following steps: (1) taking Z-1, 3-dichloropropene as a raw material, adding dimethyl sulfoxide and solid alkali into an organic solvent, heating, carrying out heat preservation reaction until the content of the Z-1, 3-dichloropropene is less than or equal to 1%, and cooling to room temperature; (2) adding a phase transfer catalyst and water into the reaction liquid obtained in the step (1), heating, and carrying out a heat preservation reaction until an intermediate 3-chloropropyl-2-ene-1-ol is less than or equal to 0.5%; cooling to room temperature; (3) filtering, separating liquid, and adding an extracting agent into a water phase for extraction; and rectifying the extracted organic phase to obtain propargyl alcohol. By controlling the alkaline strength and reaction parameters in the reaction, the production of organic impurity ether compounds can be effectively controlled, the purity and yield of the product are improved, and meanwhile, the reaction time is shortened.

The invention provides a method for comprehensively utilizing phenolic ketone tar and a petroleum fracturing proppant, and the method comprises the following steps: (1) mixing phenolic ketone tar and an acid catalyst to carry out a first heating reaction, and then adding an aldehyde compound to carry out a second heating reaction to obtain a phenolic resin mixture; (2) carrying out negative pressure rectification on the phenolic resin mixture to obtain a tower top material and a tower kettle material; wherein acetophenone is obtained after the tower top material is layered, and the tower kettle material comprises phenolic resin; (3) carrying out ring-opening reaction on the mixed phase transfer catalyst, epoxy chloropropane and phenolic resin, then adding alkali to carry out ring-closing reaction, and separating to obtain novolac epoxy resin; and (4) mixing the curing agent, the accelerant and the novolac epoxy resin for stirring reaction to obtain the petroleum fracturing propping agent. According to the method provided by the invention, acetophenone in the phenolic ketone tar can be separated out, the petroleum fracturing propping agent can be produced at the same time, the recovery energy consumption can be reduced, no solid waste is discharged, and the environmental protection requirement is met.

The invention belongs to the technical field of compounds, and provides a preparation method of 2-methyl-L-leucine hydrochloride. The method comprises the following steps: dissolving 2-amino propionate or hydrochloride thereof, an aldehyde ketone compound and alkali in a first solvent, heating for reaction, reacting with a chiral biphenyl quaternary ammonium salt phase transfer catalyst, performing deprotection reaction, performing catalytic hydrogenation reaction in a hydrogen atmosphere, and finally performing ester hydrolysis reaction to obtain the 2-methyl-L-leucine hydrochloride. The raw materials needed by the method are easy to obtain, the used catalyst and solvent can be used mechanically by 90% or above, the stereoselective chiral biphenyl quaternary ammonium salt phase transfer catalyst is adopted, the ee value of the obtained product can reach 99.5% or above without chiral resolution, the yield is high (even can reach 77.6%), no highly toxic cyanide participates in the preparation process, and the method is safe and environmentally friendly.

The invention discloses a synthesis method of 2, 4, 5-trifluorophenylacetic acid, which comprises the following steps: by taking cheap and easily available o-chloronitrobenzene as a raw material, reacting with sodium nitrate in a sulfuric acid and trifluoroacetic acid system, separating generated 2, 4-dinitrochlorobenzene through melt crystallization, and continuing to synthesize 2, 4-dinitrochlorobenzene in methyl chloroacetate to obtain 2, 4, 5-trifluorophenylacetic acid. The method comprises the following steps: carrying out indirect aromatic nucleophilic substitution reaction on 2, 4-dinitrophenylacetic acid under the condition of sodium hydride to generate 5-chloro-2, 4-dinitrophenylacetic acid methyl ester, separating, carrying out fluorination reaction on the 5-chloro-2, 4-dinitrophenylacetic acid methyl ester and potassium fluoride under the action of a phase transfer catalyst, carrying out rectification separation to obtain 2, 4, 5-trifluorophenylacetic acid, and carrying out hydrolytic acidification on the 2, 4, 5-trifluorophenylacetic acid in a sodium hydroxide aqueous solution to obtain 2, 4, 5-trifluorophenylacetic acid. And the process route is safer, more environment-friendly, more efficient and lower in cost.

The present invention relates to a process for preparing N-hydroxypyridone compounds (I) from pyrone compounds using a phase transfer catalyst. # imgabs0 #

The invention relates to a binder composition for manufacturing a wood-based material, a method for manufacturing such a wood-based material and such a wood-based material. In order to provide a binder composition for manufacturing a wood-based material, in which the speed of curing can be specifically controlled and at the same time diffusion of the binder into the wood material to be bound is prevented in the best possible way, thereby ensuring a safe, fast and cost-effective manufacturing process with the lowest possible use of binder, fast and cost-effective manufacturing process with the lowest possible binder consumption without reducing the product quality, it is provided that the binder composition comprises an organic phase having at least one polymer adhesive, an aqueous phase, at least one phase transfer catalyst for accelerating the curing of the polymer adhesive and a hydrophilizing agent comprising or formed from at least one silane compound for increasing the hydrophilicity of the polymer adhesive and / or for reducing the penetration of the polymer adhesive into the material of the wood-based material to be bonded.

The invention relates to the field of comprehensive utilization of biomass resources and preparation of high polymer materials, in particular to a green preparation method of high-deacetylation-degree chitin capable of recycling reaction waste liquid. The invention aims to solve the problems of serious environmental pollution, resource waste, low product purity and incomplete waste liquid recycling in chitin extraction. The method comprises the following steps: by taking crustacean biomass as a raw material, firstly carrying out high-voltage pulse electric field pretreatment to crush the tissue structure of the raw material and improve the reaction activity, and then heating and extracting in a choline chloride-lactic acid deep eutectic solvent system to realize efficient removal of proteins and inorganic salts in the raw material; according to the method, the chitin and the alkali liquor are subjected to a rapid deacetylation reaction by adopting microwave assistance and cooperating with the action of the phase transfer catalyst; according to the method, a waste liquid graded recycling system is adopted, hydrochloric acid in waste acid liquid generated by decalcification is recycled through electrodialysis, alkali liquid is recycled through ultrafiltration-nanofiltration double-membrane combination, deep eutectic solvent components are recycled through reduced pressure distillation, and recycling of acid, alkali and a solvent is achieved.

A method for preparing 1,2-propanediol involves continuously reacting propene with hydrogen peroxide in the presence of a catalyst mixture, containing a quaternary ammonium salt and a polytungstophosphate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase containing an alkylaromatic hydrocarbon solvent. The method then involves withdrawing the liquid reaction mixture from the reaction and adding a water-soluble sulfate salt or sulfuric acid to provide a mixture containing from 500 to 10,000 mg / kg of sulfate ions in the aqueous phase. The method further involves separating the mixture obtained into an aqueous phase (Pa) containing 1,2-propanediol and an organic phase (Po), recycling at least a part of the organic phase (Po) to the reaction, and recovering 1,2-propanediol from the aqueous phase (Pa). The method allows for extended operation of the reaction with little loss of tungsten and phase transfer catalyst.

This invention discloses a method for preparing a high-temperature resistant, strongly basic anion exchange resin, belonging to the field of ion exchange resins. The method includes three steps: First, white spheres with a crosslinking degree of 6-10 undergo a chloromethylation reaction by sequentially adding zinc dichloride and tin tetrachloride to improve the uniformity of the chloromethyl group distribution in the chlorospheres; second, the chlorospheres undergo an etherification reaction using tetrabutylammonium bromide as a phase transfer catalyst, and the dropping rate of sodium methoxide solution is controlled to improve the etherification conversion rate; finally, the etherification product undergoes a quaternization reaction with a trimethylamine aqueous solution to obtain the strongly basic anion exchange resin. This invention, by selecting the degree of crosslinking and optimizing the catalyst addition method for chloromethylation and the sodium methoxide dropping rate for the etherification reaction, results in a more uniform distribution of quaternary ammonium groups in the resin, significantly improving the ion exchange capacity and high-temperature resistance of the resin.

The invention discloses a preparation method of fluoroethylene carbonate, and belongs to the technical field of organic synthesis. According to the method, a three-in-one catalytic system of a fluorine source, a promoter and a phase transfer catalyst is constructed, so that the technical bottleneck of a traditional fluorination process is broken through. The method for in-situ generation of hydrogen fluoride comprises the following steps: taking a fluoro basic salt (such as potassium fluoride) as a fluorine source and concentrated sulfuric acid as a promoter to generate hydrogen fluoride (HF) in situ, and avoiding direct use of dangerous fluorine gas; reaction conditions are optimized: mild reaction and uniform precipitation of a byproduct (potassium chloride) are realized by adopting a composite fluorinating agent, and solid-liquid separation is facilitated. The method is high in reaction selectivity, and the yield reaches 93.5%. Raw materials are cheap and easy to obtain, equipment requirements are low, and large-scale production is facilitated. The FEC purity after rectification is gt; the lithium ion battery electrolyte additive meets the requirements of lithium ion battery electrolyte additives, and is especially suitable for the field of high-performance lithium ion batteries.

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

The invention relates to a synthetic method of 1, 4-butanediol diglycidyl ether, 1, 4-butanediol and epichlorohydrin are synthesized in one step under the action of a phase transfer catalyst, in the one-step process, once 1, 4-butanediol and epichlorohydrin are subjected to ring-opening reaction to produce a chlorohydrin ether intermediate, the chlorohydrin ether intermediate is subjected to ring-opening reaction, and the chlorohydrin ether intermediate is subjected to ring-opening reaction to produce the 1, 4-butanediol diglycidyl ether. The intermediate can be subjected to ring-closure production immediately under the action of solid alkali to produce an epoxy group, the obtained 1, 4-butanediol diglycidyl ether is relatively low in easily saponifiable chlorine content, and the target product is relatively high in purity. After the reaction is finished, sodium chloride generated by the reaction and unreacted solid caustic soda can be removed through direct suction filtration to obtain a neutral system, washing is not needed, no waste liquid is generated, operation is easy, and the method is suitable for clean industrial production.

The invention belongs to the technical field of insulating materials of high-voltage direct-current power transmission equipment, and discloses a pure epoxy crosslinking system and a preparation method and application thereof.The preparation method comprises the steps that fluorenyl bisphenol, epoxy chloropropane, a phase transfer catalyst and an alkaline solution are mixed to obtain a mixture, the mixture is subjected to impurity removal to obtain fluorenyl epoxy resin DGEBF, and the fluorenyl epoxy resin DGEBF is subjected to high-voltage direct-current power transmission equipment insulating materials. The preparation method comprises the following steps: uniformly mixing fluorene group epoxy resin DGEBF and an anhydride curing agent MTHPA, and then carrying out curing reaction to obtain a pure epoxy crosslinking system; according to the invention, the epoxy resin can have higher glass transition temperature and thermal decomposition temperature, the mechanical strength, modulus and dimensional stability of the material are improved, and good electrical insulation performance can still be maintained in a high-temperature environment.

The present invention discloses a method for preparing furfural, which includes: under the action of a heteropolyacid-based phase transfer catalyst, an intramolecular dehydration reaction occurs for xylose-based carbohydrates in a ternary two-phase reaction medium composed of a low-boiling organic solvent, a protic solvent, and an ionic organic ammonium chloride. The catalyst used in the present invention has the property of phase transfer, that is, its solubility in the reaction medium increases at high temperature, and it catalyzes the dehydration of xylose in the form of a liquid acid; after the reaction, the solubility decreases and it precipitates in the form of a solid, which is convenient for the recovery and separation of the catalyst, and largely solves the problems of low efficiency of solid acid catalysts and difficult separation of liquid acid catalysts. And an advanced reaction medium is coupled to increase the solubility of xylose-based carbohydrates and the solvation effect on xylose. Through the optimization of the catalyst and the reaction medium, the reaction performance of the reaction system is effectively improved.

The invention discloses a method for preparing a fatty alcohol ether carboxylic acid, and belongs to the technical field of synthesis of anionic nonionic-anionic surfactants in organic chemistry. The method uses a fatty alcohol as a raw material, and under the protection of an inert gas, first uses an organic base to react with a fatty alcohol ether to undergo alkalization, and under the action of a phase transfer catalyst, reacts with chloroacetate to undergo carboxymethylation, and obtains a fatty alcohol ether carboxylic acid through acidification and washing. The method for preparing a fatty alcohol ether carboxylic acid of the invention has a simple process, is easy to control in production, has high product purity, and has stable quality.

The invention relates to the technical field of bio-based high polymer materials, in particular to a vanillin-based diepoxy monomer compound as well as a preparation method and application thereof. The invention provides a brand new vanillin-based diepoxy monomer compound. A preparation method of the compound comprises the following steps: 1, synthesizing a bio-based bisphenol intermediate from bio-based platform compounds such as vanillin and vanillin under the catalysis of pyrrolidine acetate; 2, adding epichlorohydrin to synthesize a diepoxy monomer under the catalytic action of a phase transfer catalyst and base; and the epoxy resin can be reacted with a commercial curing agent to prepare high-performance bio-based epoxy resin. The glass transition temperature of the prepared high-performance bio-based epoxy resin is 170-220 DEG C, the initial decomposition index in nitrogen is 300-380 DEG C, the tensile strength is 85-120 MPa, and the high-performance bio-based epoxy resin has good mechanical properties and thermal stability.

The invention provides a synthesis method of 3-ethyl-3-[(2-oxirane methoxy) methyl] oxetane (EGMO), and belongs to the technical field of fine chemical engineering. According to the method, sodium hydroxide is taken as an alkaline reagent, and a quaternary ammonium salt or quaternary phosphonium salt phase transfer catalyst is adopted to promote the effective contact of sodium salt and epichlorohydrin, so that the conversion process of preparing 3-ethyl-3-[(2-oxirane methoxy) methyl] oxetane from 3-ethyl-3-oxetane and epichlorohydrin is catalyzed. According to the method disclosed by the invention, the EGMO is synthesized by dropwise adding the epoxy chloropropane through a one-pot method, and a product with relatively high content and relatively low color number can be obtained without distillation, so that the reaction time is shortened, the side reaction of the epoxy chloropropane is reduced, the production efficiency, the product yield and the purity are improved, and the color number of the product is reduced. The preparation process is convenient to operate, simple and suitable for industrial production.

The invention relates to a preparation method of fluoro-ether, which comprises the following steps: providing a first reaction system which comprises paratoluensulfonyl chloride, fluorine-containing alcohol, an alkali metal hydroxide aqueous solution, a phase transfer catalyst and an organic solvent which is insoluble in water; performing a first reaction on the first reaction system to generate p-toluenesulfonate, then standing for layering, and taking an organic phase; providing a second reaction system, wherein the second reaction system comprises the organic phase, fluorine-containing alcohol and an alkali metal hydroxide aqueous solution; and carrying out a second reaction on the second reaction system to generate fluoroether. The preparation method is simple in operation steps, does not need or reduces the steps of extraction, separation and the like, and has the advantage of saving reagent cost.

A process for producing a halogenated isoolefin copolymer involves contacting an unsaturated isoolefin copolymer cement, the cement comprising an unsaturated isoolefin copolymer dissolved in an organic solvent, under halogenation conditions with a halogenating agent and an aqueous solution of an oxidant and a phase transfer catalyst to form a two-phase reaction medium comprising an organic phase and an aqueous phase, the oxidant capable of converting hydrogen halide to free halogen and the phase transfer catalyst being a compound of Formula (I): Formula (I) where: M+ is a cation of a Group VA element; X− is an anion that dissociates from the cation in an aqueous solution; and, R1, R2, R3 and R4 are the same or different and are independently a C1-30 organic moiety. The process provides improved halogen recovery, is less sensitive to the presence of water, and can make use of a variety of different oxidants.

The invention belongs to the technical field of organic peroxides, and particularly relates to a preparation method of peroxide (2-ethylhexyl) tert-amyl carbonate. The preparation method comprises the following steps: (1) carrying out temperature control reaction on a tert-amyl hydroperoxide crude product and a salt-forming agent under the action of a phase transfer agent to obtain an intermediate; (2) compounding a phase transfer catalyst system, blending the phase transfer catalyst system with chloroformic acid-2-ethylhexyl ester, adding the mixture and the intermediate into a reaction kettle for substitution reaction, and after the substitution reaction is finished, standing and collecting an upper organic phase to obtain a TAEC crude product; and (3) adding a detergent into the TAEC crude product, stirring, standing, collecting an upper oil phase, and washing until the oil phase is neutral to obtain TAEC. By compounding the phase transfer catalyst system, the problems of more dicarbonate byproducts, lower TAEC yield and difficulty in catalyst recovery in the existing TAEC synthesis method are solved.

The present invention relates to a process for the preparation of Pyroxasulfone of Formula (I) or salts thereof from a compound of Formula (II) by reacting the compound of Formula (II) with a suitable oxidizing agent in presence of a metal catalyst, an inorganic acid and optionally a phase transfer catalyst. Formula (I) Formula (II).

The invention discloses a green synthesis method of 4, 6-dimethoxy-2-(methylthio) pyrimidine, which comprises the following steps of: synthesizing 4, 6-dimethoxy-2-(methylthio) pyrimidine; according to the method, 4, 6-dihydroxypyrimidine-2-sodium sulfide is taken as a raw material, low-toxicity and harmless dimethyl carbonate is taken as a methylation reagent, lewis acid is added to serve as a catalyst, a reaction is performed in a phase transfer catalyst, and a 4, 6-dimethoxy-2-methylthio pyrimidine solid is prepared. The synthesis method disclosed by the invention has the advantages of cheap raw materials, simple synthesis method and high yield, toxic and harmful reagents in a fractional step method are avoided, the used phase transfer catalyst can be recycled and reused, and the synthesis method is suitable for commercial production.

The invention provides hydrogenated bisphenol A epoxy resin and a preparation method thereof, and belongs to the technical field of epoxy resin preparation, the preparation method comprises the following steps: (1) dissolving hydrogenated bisphenol A in a solvent, heating, and carrying out reflux dehydration; (2) mixing the hydrogenated bisphenol A subjected to reflux dehydration with a catalyst, and then adding epoxy chloropropane for etherification ring-opening reaction to obtain chlorohydrin ether; (3) adding an alcohol auxiliary agent, then adding alkali, and carrying out closed-loop epoxidation reaction; (4) supplementing a solvent and water, stirring, standing for layering, removing lower-layer saline water, and taking an upper-layer organic layer; and (5) post-processing to obtain the hydrogenated bisphenol A epoxy resin. According to the method disclosed by the invention, by adding the alcohol auxiliary agent, the closed-loop epoxidation reaction can be thorough by adding alkali under normal pressure, the effect of the closed-loop epoxidation reaction can be remarkably improved, a phase transfer catalyst does not need to be added in the reaction process, and decompression reflux dehydration is also not needed, so that reaction equipment and operation are greatly simplified.

The invention relates to the field of silane coupling agents, and discloses a preparation method of a sulfur-containing silane coupling agent, which comprises the following steps: step 1, mixing alkali metal sulfide with sulfur, stirring, and reacting to obtain a sodium polysulfide solution; step 2, adding a pH regulator, a hydrolysis inhibitor and a phase transfer catalyst into the sodium polysulfide solution, dropwise adding 3-halogen propyl trialkoxysilane, and stirring for condensation reaction to obtain a crude product reaction solution; 3, the crude product reaction liquid is sequentially subjected to distillation, decolorization with a decolorizing agent and filtration, and the sulfur-containing silane coupling agent is prepared after the steps are completed. The crystal water contained in the raw materials is used as a reaction medium, so that additional addition of an organic solvent and pre-drying and dehydration treatment are not needed, the spontaneous combustion risk of sodium sulfide is avoided, raw material pretreatment and solvent recovery procedures are omitted, and the whole technological process is simplified, so that the operation is simple and convenient, and the cost is low. The method is suitable for large-scale industrial production.