437 results about "Phase-transfer catalyst" patented technology

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 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 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 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 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.

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.

The invention provides a carbon fiber recovery method and a carbon fiber. The carbon fiber recovery method comprises the following steps: treating a carbon fiber prepreg into a chopped material with a preset size; placing the chopped material in an acidic medium, and carrying out first treatment under the action of a phase transfer catalyst to obtain an intermediate fiber product; and placing the intermediate fiber product in an alkaline medium, and carrying out second treatment under the action of a phase transfer catalyst to obtain the carbon fiber. According to the carbon fiber recovery method provided by the invention, through sequential design of acidolysis (first treatment)-alkali washing (second treatment), the problem of interface pollutant residues in carbon fiber recovery is solved. A first treatment process in an acidic medium exfoliates the polymer matrix, clearing obstacles for a subsequent second treatment in an alkaline medium. In the second treatment process in the alkaline medium, the interface of the intermediate fiber product is cleaned, the sizing agent is thoroughly removed, the performance of the carbon fibers can be reserved through the recycling method, and the clean carbon fibers can be obtained.

The invention provides a preparation method of bis-[3-(triethoxysilyl) propyl]-disulfide. The preparation method comprises the following steps: S1, under the protection of nitrogen, dropwise adding chloropropene and trichlorosilane into a non-polar solvent, a first catalyst and tripropylamine, reacting at room temperature, taking filtrate, dropwise adding the filtrate into alcohol in a micro-reflux state, reacting, adding a sodium alkoxide / alcohol solution for neutralizing, filtering, and distilling to obtain allyltriethoxysilane; and S2, under ultraviolet light, mixing allyltriethoxysilane, mercaptopropyltriethoxysilane and benzoin dimethyl ether, reacting at room temperature for 2-3 hours, adding sulfur and a second catalyst, carrying out heating reaction, removing low boiling points, cooling, and filtering. According to the preparation method provided by the invention, bis-[3-(triethoxysilyl) propyl]-disulfide is successfully and effectively synthesized, a phase transfer catalyst does not need to be introduced for catalysis, hydrolysis of silane and treatment of saline water are reduced, the yield of single-kettle synthesis is high, and the utilization rate of equipment is high.

This invention discloses a method for synthesizing dialkylphosphinates, belonging to the field of organic synthesis technology. The method uses hypophosphite and haloalkanes as starting materials. First, a hypophosphite is generated through a heated and pressurized reaction under the action of a phase transfer catalyst. The obtained hypophosphite does not require complex purification; it is directly reacted with an olefin under heated and pressurized conditions in the presence of a free radical initiator to obtain the target product, dialkylphosphinate. The method of this invention uses inexpensive and readily available raw materials, has a simple process route, includes only two core reactions, operates under mild conditions, is safe and convenient, produces few and easily treatable byproducts, has a high product yield, and is simple to purify. It is very suitable for large-scale industrial production, providing an economical and efficient synthetic route for the preparation of high-performance halogen-free flame retardants.

The invention provides a preparation method for synthesizing 5-hydroxymethylfurfural by catalyzing glucose through a phosphotungstic acid modified molecular sieve catalyst. Organic amine is adopted as a template to synthesize a silicoaluminophosphate (SAPO) molecular sieve, the SAPO molecular sieve subjected to high-temperature activation is adopted as a catalyst, the SAPO molecular sieve and phosphotungstic acid are subjected to composite roasting, a phase transfer catalyst is added into a two-phase medium of an organic solvent and water, glucose is dehydrated and converted into 5-hydroxymethylfurfural (5-HMF), the yield of the 5-HMF is 50% or above, and the selectivity of the 5-HMF exceeds 90%. After the catalyst is recycled for multiple times, the yield of 5-HMF exceeds 40%.

The present disclosure relates to the synthesis of Vitamin K2 bearing varying prenyl side chains. The synthesis comprises the reaction of phenyl sulfone of tert-butyl dimethyl silyl (TBDMS) protected mono prenyl menadiol with prenyl halides bearing varying prenyl units in the presence of the phase transfer catalyst followed by reductive desulphonation to yield TBDMS ether of Vitamin K2. The TBDMS ether is then oxidized in the presence of chromium trioxide and periodic acid to yield the corresponding Vitamin K2.

The invention discloses a synthesis method of mannitol carbonate sulfate, and belongs to the technical field of organic synthesis. The synthesis method provided by the invention comprises the following steps: reacting 1, 3, 4, 6-tetrachloro-2, 5-hexanediol with chlorosulfonic acid in the presence of an acid-binding agent to obtain an intermediate solution as shown in a formula (II); formula (II); and mixing the intermediate solution as shown in the formula (II) with anhydrous carbonate, heating to a first set temperature for reaction, and then heating to a second set temperature for reaction in the presence of a phase transfer catalyst to obtain the mannitol carbonic sulfate. The whole process route is short, the yield is high, and the total yield of two steps reaches 88% or above; meanwhile, few by-products are generated, the purification difficulty is low, the reaction time is short, few hazardous wastes are generated, operation is easy and convenient, and industrial large-scale production is facilitated.

The application relates to a preparation method and application of a performance-adjustable reactive cationic polymer, and belongs to the field of textile printing and dyeing. The preparation method of the performance-adjustable reactive cationic polymer comprises the following process steps: mixing an epoxy reactive monomer with concentrated hydrochloric acid, reacting for a certain time under ice bath, and adjusting the pH of the reaction system to be neutral; adding a cationic monomer into the above reaction system, simultaneously adding a phase transfer catalyst or an organic solvent, adding an initiator drop by drop under a nitrogen atmosphere, stirring to carry out a free radical polymerization reaction, naturally cooling after the reaction is completed, and drying to obtain the reactive cationic polymer. According to the application, salt-free high-color-yield dyeing of reactive dyes can be realized when the amount of the cationic polymer is very low.

The invention belongs to the technical field of preparation of 3-cyclohexylamino propanesulfonic acid, and particularly relates to a preparation method of 3-cyclohexylamino propanesulfonic acid. The preparation method of the 3-cyclohexylamino propanesulfonic acid comprises the following steps: (1) preparing a sodium hydroxypropanesulfonate aqueous solution; (2) dissolving cyclohexylamine in an organic solvent, adding a phase transfer catalyst, then stirring and heating until reflux, and then dropwise adding a sodium hydroxypropanesulfonate aqueous solution for reaction; (3) acidification reaction; and (4) preparing the 3-cyclohexylamino propanesulfonic acid. According to the preparation method of the 3-cyclohexylaminopropanesulfonic acid, the adopted phase transfer catalyst can be combined with the hydroxy propanesulfonic acid sodium salt in the aqueous solution, transferred into the organic phase and reacted with cyclohexylamine in the organic phase to generate the 3-cyclohexylaminopropanesulfonic acid, and then the solvent is evaporated out instead of layering, so that the 3-cyclohexylaminopropanesulfonic acid is obtained. And the condition that the 3-cyclohexylamino propanesulfonic acid is taken out when the organic solvent is delaminated and removed is effectively avoided.

1,2-propanediol is prepared by a process comprising the steps of: step a) reacting propene with hydrogen peroxide in the presence of a catalyst mixture comprising a phase transfer catalyst and a polytungstophosphate at 50-110°C in a liquid reaction mixture comprising an aqueous phase having a maximum apparent pH of 6 and an organic phase; step b) separating the reaction mixture into an aqueous phase (P a ) and an organic phase (P o ) comprising 1,2-propanediol; step c) recycling at least a portion of the separated organic phase (P o ) to step a); step d) recovering 1,2-propanediol from the aqueous phase (P a ); and step e) reacting a tungstate with hydrogen peroxide and phosphoric acid in the presence of a phase transfer catalyst in a liquid mixture comprising an aqueous phase and an organic phase at 5-40°C, followed by passing at least a portion of the resulting organic phase comprising polytungstophosphate and phase transfer catalyst to reaction step a).

The invention belongs to the technical field of medicine synthesis processes, and particularly relates to a preparation method of high-yield and high-purity tandospirone citrate. According to the method, pyrimido piperazine quaternary ammonium salt and isoindoledione are used as raw materials, a toluene and n-butanol and / or n-amyl alcohol mixed solvent is used as a solvent, tandospirone can be generated under the alkaline condition without adding a phase transfer catalyst, after acid adjustment extraction and specific organic solvent reverse phase impurity removal, a water phase is adjusted to be alkaline, and the tandospirone is obtained. And extracting with toluene, and adding a citric acid ethanol solution to directly separate out a citric acid tandospirone solid. The preparation process disclosed by the invention has a very good impurity removal effect, and the obtained tandospirone citrate is high in purity, high in process yield, good in atom economy and low in output of three wastes.

The method for producing an aromatic polysulfone has a step for reacting an aromatic polysulfone precursor with a compound represented by (A). The aromatic polysulfone precursor has a repeating unit including a structure represented by formula (S-1) in the main chain and has a halogen atom at a main chain end. The step is carried out in an aprotic organic solvent in the presence of an alkali metal salt and a phase transfer catalyst. -ph1-SO2-ph2-O- … (S-1) [ph1, ph2: optionally substituted phenylene group] (Ra)x-Ar-OM … (A) [Ar: optionally substituted aromatic hydrocarbon group. Ra: one or more polar groups selected from the group consisting of acidic groups having a pKa equal to or less than the pKa of a carboxy group, salts of the acidic groups, and functional groups containing a nitrogen atom. x: integer of 1 or more. M: hydrogen atom or monovalent cation ]