44 results about "Phthalimide" patented technology

The present invention provides a method for neutralizing the odor (purifying), of a technical phthalimide-based fungicide comprising (1) mixing (i) slurry of phthalimide-based fungicide in water with (ii) ammonium hydroxide solution, preferably followed by, (2) filtration of the phthalimide-based fungicide and (3) drying.

The invention discloses a PBT (polybutylene terephthalate) composition as well as a preparation method and application thereof. The PBT composition is prepared from the following components in parts by weight: 44 to 56 parts of PBT resin; 10 to 15 parts of ethylene bis (tetrabromo) phthalimide; 25 to 35 parts of glass fiber; and 0.5-1 part of an ultraviolet light absorber. According to the glass fiber reinforced PBT composition disclosed by the invention, the specific ethylene bis (tetrabromo-phthalimide) is added into the glass fiber reinforced PBT composition and is matched with the specific ultraviolet light absorber, so that the prepared PBT composition has an effect of small color difference change after aging; and the method is particularly suitable for workpieces with long-time outdoor working condition requirements, such as intelligent ship outdoor units, photovoltaic supports, air conditioner outdoor unit components, new energy battery parts and the like.

The invention relates to the technical field of organic synthesis, in particular to a preparation method of N, N '-dichloro-1, 4-benzenedicarboxamide, which comprises the following steps: taking terephthalamide as an initial raw material and tert-butyl hypochlorite as a chlorination reagent; the method comprises the following steps: carrying out a chlorination reaction on terephthalamide and tert-butyl hypochlorite in a solvent under the protection of inert gas by controlling the reaction temperature, and after the reaction is finished, carrying out post-treatment to obtain N, N-dichloro-1, 4-phthalimide. The preparation method of the N, N '-dichloro-1, 4-benzenedicarboxamide comprises the following steps: taking terephthalamide and tert-butyl hypochlorite as raw materials, and carrying out one-step reaction to generate a dichloro product. Compared with a traditional N, N '-dichloro-1, 4-benzenedicarboxamide production method, the preparation method has the advantages that the amount of three wastes generated is small, the product yield is high, the product purity is high, the operation is safe and convenient, and the preparation method is more suitable for industrial application.

The invention discloses four-arm polyethylene glycol amine as well as a preparation method and application thereof, relates to the technical field of high polymer materials, and solves the problems of poor comprehensive properties such as strength, fatigue resistance and swelling resistance when traditional dual-network hydrogel is applied to preparation of a cartilage repair material in the prior art. The molecular weight of four-arm polyethylene glycol amine provided by the invention is 10 kDa or 40 kDa, four-arm polyethylene glycol, phthalimide, diisopropyl azodicarboxylate and triphenylphosphine are subjected to a Mitsunobu reaction and hydrazinolysis, and the four-arm polyethylene glycol amine with the molecular weight of 10 kDa is obtained; four-arm polyethylene glycol, phthalimide, diisopropyl azodicarboxylate and triphenylphosphine are subjected to a Mitsunobu reaction and hydrazinolysis, and four-arm polyethylene glycol amine with the molecular weight of 40 kDa is obtained. The double-network hydrogel prepared from the four-arm polyethylene glycol amine has excellent comprehensive performance such as high mechanical strength, fatigue resistance, self-recovery performance and swelling resistance, and can be applied to preparation of cartilage-like materials.

The application provides a preparation method of a rare earth metal adsorption and separation resin and a resin extraction column. The preparation method comprises the following steps: adding an oil phase composed of styrene, divinylbenzene, a pore former and an initiator into an aqueous phase containing a dispersant and an inorganic salt to perform suspension polymerization, so as to obtain a white ball resin; performing phthalimide and hydrolysis on the white ball resin, so as to obtain a primary amine resin; performing reaction on the primary amine resin with chloroacetic acid and an alkaline medium, so as to perform carboxymethylation on part of the primary amine sites; and performing reaction on the obtained intermediate resin with phosphorous acid, formaldehyde and an acidic medium, so as to perform phosphonic acid methylation on the remaining part of the primary amine sites. The white ball resin is first subjected to amination, and then part of the carboxymethylation and part of the phosphonic acid methylation are sequentially performed, so that the carboxyl type chelation sites and the phosphonic acid type chelation sites are simultaneously reserved in the same resin bead, thereby being beneficial to improving the comprehensive adsorption performance and separation performance of the resin on the rare earth metal.

Four-arm polyethylene glycol amine and preparation method and application thereof, relate to the technical field of high polymer materials, and solve the problem of poor comprehensive performance such as strength, fatigue resistance and swelling resistance when the traditional double network hydrogel is applied to the preparation of cartilage repair materials in the prior art. The four-arm polyethylene glycol amine provided by the application has a molecular weight of 10 kDa or 40 kDa. Four-arm polyethylene glycol, phthalimide, diisopropyl azodicarboxylate and triphenylphosphine are subjected to Mitsunobu reaction and hydrazinolysis to obtain four-arm polyethylene glycol amine with a molecular weight of 10 kDa. Four-arm polyethylene glycol, phthalimide, diisopropyl azodicarboxylate and triphenylphosphine are subjected to Mitsunobu reaction and hydrazinolysis to obtain four-arm polyethylene glycol amine with a molecular weight of 40 kDa. The double network hydrogel prepared from the four-arm polyethylene glycol amine has excellent comprehensive performance such as high mechanical strength, fatigue resistance, self-recovery and swelling resistance, and can be applied to the preparation of cartilage-like materials.

The application discloses a synthesis method of C3-substituted quinoxaline ketone derivatives and application thereof. A series of C3-substituted quinoxaline ketone derivatives with both terpene and quinoxaline ketone biological activity skeletons are obtained by using N-alkoxy phthalimide and quinoxaline ketone as starting substrates, under the catalysis of a photocatalyst and visible light irradiation, and at a temperature of 55-65 DEG C for 10-15 h. The application has the advantages of stable and easy-to-prepare raw materials, mild reaction conditions, simple experimental operation, good chemical selectivity and functional group tolerance, and is a green chemical synthesis method with good application prospect. The activity experiment results show that the synthesized C3-substituted quinoxaline ketone derivatives have good inhibiting effect on the growth of plant pathogenic fungi.

The invention provides a method for preparing a cyano compound from N-acyloxy phthalimide and olefin, which specifically comprises the following steps: by taking N-acyloxy phthalimide and olefin as reactants, adding a catalyst, a ligand, a photosensitizer and trimethylsilyl cyanide, and carrying out alkyl cyanation reaction and / or amino cyanation reaction to obtain the cyano compound. An alkyl cyano compound and / or an amino cyano compound are / is obtained; the catalyst is Cu (CH3CN) 4BF4, and the ligand is a chiral bisoxazoline ligand; and the photosensitizer is 3DPA2FBN (3, 4 '- According to the invention, controllable generation of free radicals at a carbon center and a nitrogen center can be realized by accurately regulating and controlling a metal / ligand ratio, and high-selectivity olefin alkyl cyanation and amino cyanation reactions are realized under mild conditions, so that an accessible chemical space is expanded, the multifunctionality of a synthetic route is improved, and the method is suitable for industrial production. The application range of the N-acyloxy phthalimide in free radical chemistry is obviously expanded.

The application discloses a production process of trans-zeatin, which comprises the following steps: refluxing E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide with sodium hydroxide in methanol to obtain (E)-4-amino-1-hydroxy-2-methyl-2-butene; filtering and collecting the filtrate and concentrating the filtrate; and reacting the concentrated filtrate with 6-chloropurine in n-propanol and triethylamine as an acid-binding agent to finally obtain trans-zeatin. The application uses E-2-(4-hydroxy-3-methyl-2-butene)-phthalimide as a raw material, and high-purity trans-zeatin is obtained through two steps. The preparation method can effectively improve the yield of trans-zeatin, is simple and convenient to operate, is convenient for industrial popularization, and has good economic and social benefits.

The utility model provides an aromatic hydrocarbon separation device which comprises an extractive distillation tower and a solvent recovery tower, the bottom of the extractive distillation tower is connected with the solvent recovery tower through a connecting pipe, the bottom of the solvent recovery tower is connected with the extractive distillation tower through a solvent recovery pipe, and an N-hydroxymethyl phthalimide feeding pipe is arranged on the connecting pipe. A triethanolamine feeding pipe is arranged on the N-hydroxymethyl phthalimide feeding pipe; a triethanolamine feeding pipe is arranged on the N-hydroxymethyl phthalimide feeding pipe; a sulfolane inlet pipe, an N-hydroxymethyl phthalimide inlet pipe, a triethanolamine inlet pipe and a crude aromatic hydrocarbon inlet pipe are arranged on one side of the extractive distillation tower; the bottom of the solvent recovery tower is connected with the extractive distillation tower through a solvent recovery pipe. The device can improve the recovery rate of aromatic hydrocarbon and is simple in structure.

The present invention relates to a resin composition using an imide curing agent, comprising components counted by weight parts: 50 - 70 parts of a phosphorus-containing epoxy resin, 15 - 25 parts of a bisphenol A epoxy resin, 15 - 30 parts of a composite curing agent composed of a nitrogen-containing phenolic resin and N-(4'-amino)-phenyl-(4-amino)phthalimide, and 0.02 - 0.30 parts of an imidazole curing accelerator; The advantages of the present invention are that a resin composition containing an imide curing agent is adopted. This composition is based on a phosphorus-containing epoxy resin and combines with a nitrogen-containing curing agent to form a synergistic flame retardant effect. Without adding other organic or inorganic flame retardants, a prepreg made of this composition can be used. The laminate prepared using this prepreg reaches UL94 V0 level, achieving halogen-free flame retardancy, and the laminate also has excellent glass transition temperature, peel strength, heat resistance and alkali resistance.

The invention discloses modified asphalt mortar for road repair and a preparation method thereof, and relates to the field of asphalt mortar. When the modified asphalt mortar for road repair is prepared, 4-allyloxy-2-hydroxybenzophenone and octa-aminopropyl cage-like polysilsesquioxane are subjected to a reaction, and modified cage-like polysilsesquioxane is prepared; the preparation method comprises the following steps: sequentially reacting quartz sand with 3-aminopropyltrimethoxysilane and maleic anhydride to prepare modified quartz sand; the preparation method comprises the following steps: polymerizing glycidyl methacrylate, N, N-dimethylacrylamine and 2-allyl furan, and then reacting with N-(trifluoromethylthio) phthalimide to prepare a modified epoxy polymer; asphalt is heated and then mixed with the modified epoxy polymer, the modified quartz sand and the modified polyhedral oligomeric silsesquioxane, and the modified asphalt mortar for road repairing is prepared. The prepared modified asphalt mortar for road repairing has waterproof, self-repairing, high-temperature-resistant and anti-aging capabilities.

The invention relates to the technical field of gas dust removal, in particular to a phthalimide drying dust removal filtering device which comprises a dust removal box body, a conveying opening is formed in one side of the dust removal box body, a backflow pipe is fixedly installed in the conveying opening, and a heat exchange box is fixedly installed at the other end of the backflow pipe. A heat exchange assembly is fixedly mounted in the heat exchange box; dust gas enters the multiple heat exchange pipes through the gas flow dividing shell and makes contact with heat exchange water in the heat exchange box when entering the heat exchange pipes, the dust gas is cooled, meanwhile, the temperature of a water body is increased, particulate matter in filtered purified water is filtered through a liquid exchange filter plate, and the particulate matter in the purified water is filtered through circulation of a water pump; and the high-temperature dust gas is pretreated and cooled, so that the problem that the dust removal efficiency is seriously reduced due to instant gasification when the high-temperature dust gas is in contact with water mist when the temperature of the high-temperature dust gas is too high is prevented.

The invention relates to the field of isopropyl alcohol preparation, and discloses a chelate resin and a preparation method thereof, and a method for preparing electronic grade isopropyl alcohol, the method comprises the following steps: styrene-divinylbenzene polymeric microspheres are contacted with N-hydroxymethyl phthalimide, and an imidization reaction, a hydrolysis reaction and a carboxylation reaction are sequentially carried out. By using the chelate resin and the method for preparing the electronic-grade isopropanol, the content of isopropanol in the product can be effectively increased, and the content of water, zwitterions and particles can be reduced.

The invention provides a preparation method of an ompacycline intermediate, which comprises the following steps: by taking minocycline hydrochloride and N-hydroxymethyl phthalimide as starting raw materials, directionally generating a 9-site substituent through a catalyst, and then synthesizing 9-aminomethyl minocycline. The method has the advantages of simple process operation, few side reaction products, high purity of the obtained intermediate, and suitableness for the production of the OMM.

The invention relates to a preparation method of 3-bromo-2-methyl-6-methylsulfonyl benzaldoxime, and belongs to the technical field of pesticides. The preparation method comprises the following steps: by taking 2, 3-dimethyl-4-methylsulfonyl bromobenzene as a raw material and adopting an organic solvent, adding a metal salt catalyst and N-hydroxyphthalimide, dropwise adding n-butyl nitrite into a system at a certain temperature, carrying out a heat preservation reaction after dropwise adding, and carrying out post-treatment after the reaction is finished, so as to obtain the 3-bromo-2-methyl-6-methylsulfonyl benzaldoxime. According to the invention, the dosage of the oximation reagent n-butyl nitrite is reduced, and the yield of oximation reaction is improved. According to the method, the reaction conditions are mild, low-temperature dropwise adding and high-temperature reaction are converted into normal-temperature reaction, meanwhile, the reaction time is shortened, and the production energy consumption is reduced.

A method for direct decarboxylative iodination of alkyl carboxylic acids by photo-oxidative reduction / copper co-catalysis relates to the field of organic compound synthesis. The method is to add alkyl carboxylic acid, iodine reagent, N-hydroxy phthalimide compound, alkaline substance, ligand, copper catalyst, photocatalyst and olefin additive into a solvent under an argon atmosphere, to produce an active ester intermediate in situ under the driving of visible light, and then to occur free radical-mediated decarboxylative iodination to synthesize a series of alkyl iodides. The reaction condition is mild, the operation is simple, has a wide substrate range and good functional group tolerance. The method can realize the late-stage modification of complex natural products and drug molecules, further proving the practicability of the method. The method uses stable, low-toxicity, cheap and easily available alkyl carboxylic acid to directly realize the synthesis of alkyl iodide, without the need for additional steps to pre-activate it, and is more in line with the concept of modern green chemistry.

The invention belongs to the technical field of preparation of chemical intermediates, and particularly relates to a method for recovering N-hydroxymethyl phthalimide from 4-AA key intermediate residues. Comprising the following steps: (1) distillation: filtering and distilling toluene mother liquor generated in preparation of 4-AA key intermediate 2-(N-phthalimido methyl)-3-oxobutyric acid methyl ester to obtain a toluene solvent and concentrated residues, and recycling the toluene solvent; (2) hydrolysis: a hydrolysis reagent is added into the concentrated residues, the weight ratio of the concentrated residues to the hydrolysis reagent is 1: (1.1-4), the temperature is increased to 30-100 DEG C, heat preservation hydrolysis is conducted for 1-10 h under stirring, and a hydrolysis product is obtained; and (3) recovery: cooling the hydrolysis product, crystallizing, filtering, and washing with water to obtain the N-hydroxymethyl phthalimide. According to the method, effective components in the hazardous waste can be recovered, so that the discharge of the hazardous waste is reduced, and the hazardous waste treatment cost is reduced.

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 3, 4-dichlorobenzotrifluoride, which comprises the following steps: firstly, adding dibenzoyl peroxide and N-hydroxyphthalimide into parachlorotoluene, and performing side chain chlorination reaction under ultraviolet irradiation and chlorine atmosphere to generate parachlorobenzotrifluoride; secondly, the obtained p-chlorobenzotrifluoride and tetrabutylammonium fluoride and potassium fluoride composite fluorination reagent are subjected to a fluorination reaction in the presence of a copper powder-1, 10-phenanthroline complex, and p-chlorobenzotrifluoride is prepared; and finally, under the catalysis of the mesoporous silica supported ferric trichloride catalyst, performing aromatic electrophilic chlorination on chlorobenzotrifluoride and sulfuryl chloride to obtain the high-purity 3, 4-dichlorobenzotrifluoride. Through synergistic application of photochemical chlorination, a composite fluorination system and the supported catalyst, the method has the advantages of mild reaction conditions, safe operation, high yield and good selectivity, and is suitable for industrial production.

The invention relates to a resin composition using an imide curing agent. The resin composition comprises the following components in parts by weight: 50-70 parts of phosphorus-containing epoxy resin, 15-25 parts of bisphenol A epoxy resin, 15-30 parts of a composite curing agent consisting of nitrogen-containing phenolic resin and N-(4 '-amino)-phenyl-(4-amino) phthalimide, and 0.02-0.30 part of an imidazole curing accelerator, the invention has the advantages that the resin composition containing the imide curing agent is adopted, the composition takes the phosphorus-containing epoxy resin as a main body and is combined with the nitrogen-containing curing agent to form a synergistic flame-retardant effect, a prepreg prepared from the composition can also be used without adding other organic or inorganic flame retardants, a laminated board prepared from the prepreg reaches UL94V0 level, and the flame-retardant property of the laminated board is greatly improved. And moreover, the laminated board also has excellent glass transition temperature, peel strength, heat resistance and alkali resistance.

The present invention discloses a modified asphalt mortar for road repair and its preparation method, which relates to the field of asphalt mortar. When preparing the modified asphalt mortar for road repair in the present invention, 4-acryloxy-2-hydroxybenzophenone is reacted with octaaminopropylcage polyhedral oligomeric silsesquioxane to obtain modified cage polyhedral oligomeric silsesquioxane; quartz sand is successively reacted with 3-aminopropyltrimethoxysilane and maleic anhydride to obtain modified quartz sand; glycidyl methacrylate, N,N-dimethylallylamine, and 2-allylfuran are polymerized and then reacted with N-(trifluoromethylthio)phthalimide to obtain modified epoxy polymer; the asphalt is heated and mixed with the modified epoxy polymer, modified quartz sand, and modified cage polyhedral oligomeric silsesquioxane to obtain the modified asphalt mortar for road repair. The modified asphalt mortar for road repair prepared by the present invention has the abilities of waterproofing, self-healing, high temperature resistance, and anti-aging.

The application discloses a preparation method of functionalized polyolefin and belongs to the technical field of polymer modification. The preparation method comprises the following preparation steps: uniformly mixing polyolefin, grafting monomers and high-valence iodine compounds, and then heating and reacting to obtain the functionalized polyolefin; wherein the grafting monomers are at least one selected from N-hydroxy phthalimide and derivatives thereof and N-hydroxy succinimide and derivatives thereof. The preparation method uses high-valence iodine compounds as initiators, can preferentially activate polyolefin molecular chains, and forms a pre-combination body with the grafting monomers, thereby greatly inhibiting the non-selective initiation of beta-scission degradation and inter-chain crosslinking of free radicals on the polyolefin main chain, maintaining the stability of the base molecular weight, and realizing efficient grafting of the grafting monomers.

The application discloses a kind of synthesis methods of high-purity 2-bromo-6-nitrobenzaldehyde, belong to organic synthesis technical field, the synthesis method is at 20-30 ℃, 1,2-dichloroethane, 2-bromo-6-nitrotoluene is mixed, stirring is dissolved, N-bromine phthalimide and initiator are mixed, heating to 70-100 ℃, reflux reaction, cooling to 20-30 ℃, post-processing is obtained compound A;Compound A is mixed with acetonitrile, temperature control is 0-10 ℃, batch is added urotropine, stirring is at 20-40 ℃, acetic acid is added, stirring is at 70-100 ℃, post-processing is obtained 2-bromo-6-nitrobenzaldehyde;The synthesis method of the application can solve the problems of low product yield, low purity, poor quality, serious three waste pollution, high cost and difficult industrialization existing in the prior art of 2-bromo-6-nitrobenzaldehyde synthesis method.

The invention relates to the technical field of organic synthesis, and particularly discloses a preparation method of bisphenol-type phthalimide, which comprises the following steps: adding a solvent E into a reaction flask under the protection of inert gas, then adding a raw material bisphenol compound A, a raw material halogenated or nitro substitute B, an alkali compound C and a catalyst D, and reacting for 2-4 hours; and finally, adding the solvent E again to adjust the solid content of the reaction system to be 5-40%, heating to 25-180 DEG C, reacting for 8-72 hours, and after the reaction is finished, sequentially filtering, concentrating under reduced pressure, purifying, performing rotary evaporation and drying to obtain the bisphenol phthalimide. The bisphenol-substituted phthalimide is prepared from the bisphenol monomer and the halogenated or nitro-substituted phthalimide through a one-step oxidative coupling method under the action of the catalyst, and the preparation method is simple in process operation, mild in reaction condition, mature and stable in process route and beneficial to industrial stable production.

The application belongs to the field of medicine synthesis, and particularly discloses a preparation method of 7-demethylomaline. The application takes 7-aminoomaricin as a starting material, carries out N-benzyl and N-methyl, then carries out substitution reaction by using N-hydroxymethyl phthalimide, carries out amine reduction reaction by using sodium borohydride and tert-pentanol, and finally carries out benzyl removal by using pd / C hydrogenation to obtain 7-methylomaline. The route can prepare the target product with a total yield of 55%. The application can prepare the impurity control of 7-methylomaline with high purity, improve the accuracy of qualitative and quantitative analysis of the impurity, is conducive to strengthening the control of the impurity, and further improves the quality of omaline finished products.

This invention discloses a method for preparing 1,2,3,6-tetrahydrophthalimide, comprising the following steps: using cis-1,2,3,6-tetrahydrophthalic anhydride as the reaction substrate and a gradient-release composite ammonia source as the ammonia donor, a cyclization reaction is carried out in an ionic liquid reaction system to obtain a crude reaction solution containing 1,2,3,6-tetrahydrophthalimide; the obtained crude reaction solution is cooled to crystallize, solid-liquid separation is performed, and drying is carried out to obtain 1,2,3,6-tetrahydrophthalimide; the ionic liquid reaction system uses an imidazole-based ionic liquid as the main reaction medium; the gradient-release composite ammonia source is composed of a first ammonia source and ammonium acetate; the preparation method provided by this invention, through the buffering effect of the gradient-release composite ammonia source combined with the imidazole-based ionic liquid, combined with a segmented temperature-controlled reaction scheme, matches the ammonia consumption requirements at different stages of the cyclization reaction, effectively suppresses the carbon-carbon double bond polymerization side reaction, reduces impurity generation, and significantly improves the yield and purity of the product.

This invention belongs to the field of chemical intermediate preparation technology, and particularly relates to a method for recovering N-hydroxymethyl phthalimide from the residue of a key intermediate of 4-AA. The method includes the following steps: (1) Distillation: The toluene mother liquor produced from the preparation of methyl 2-(N-phthaliminomethyl)-3-oxobutyrate, a key intermediate of 4-AA, is filtered and distilled to obtain toluene solvent and concentrated residue. The toluene solvent is recovered and reused. (2) Hydrolysis: A hydrolysis reagent is added to the concentrated residue, with a weight ratio of concentrated residue to hydrolysis reagent of 1:(1.1-4). The mixture is heated to 30-100℃ and kept at this temperature for 1-10 hours with stirring to obtain a hydrolysis product. (3) Recovery: The hydrolysis product is cooled, crystallized, filtered, and washed with water to obtain N-hydroxymethyl phthalimide. This invention can recover effective components from hazardous waste, thereby reducing the discharge of hazardous waste and lowering the cost of hazardous waste treatment.

The present application relates to the fields of medicine, organic chemical industry and fine chemical industry, and particularly relates to an alkyl trifluoromethyl sulfide compound and a synthesis method thereof. Under the protection of inert gas, a non-activated alkene is used as a substrate, N-trifluoromethyl thiosaccharin or N-trifluoromethylthio phthalimide is used as a trifluoromethylthio source, cyclohexyl mercaptan, p-methyl phenyl mercaptan or 2-methyl mercaptoacetate is used as a hydrogen source, inorganic alkali and organic photocatalyst are added in a reaction system, blue light is irradiated, and different substituted alkyl trifluoromethyl sulfide compounds are synthesized under room temperature conditions. The trifluoromethylthio reagent used in the present application is easy to prepare and has good stability, and the participation of noble metal silver salt is avoided. A 7.5% sodium hypochlorite solution is used for post-treatment to remove the unreacted mercaptan. The synthesis reaction condition involved in the present application is mild, the reaction efficiency is high, the regioselectivity is good, the universality is excellent, and the functional group compatibility is good.

The invention discloses a preparation method of phthaloyl amlodipine, and belongs to the technical field of chemical synthesis of medicines. In order to solve the problems of more byproducts, low intermediate purity, high cost and the like in the existing process, a process route is constructed by adopting a step-by-step convergent cyclization thought, and a four-step continuous reaction route is designed; comprising the following steps: carrying out negative pressure dehydration synthesis on high-purity N-(2-ethoxyl) phthalimide, carrying out etherification reaction under low temperature, inert gas protection and an anhydrous system, carrying out condensation reaction under reflux water separation, and carrying out Michael addition-closed-loop cyclization reaction, so as to prepare the high-purity phthaloyl amlodipine with the melting point of 149-150 DEG C; by optimizing the raw material ratio and process parameters in the reaction process, the production cost is remarkably reduced, and a high-stability raw material is provided for producing amlodipine.

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing 4-acetylpyridine from pyridine, which comprises the following steps: reacting pyridine serving as an initial raw material with acetic anhydride and iron powder to obtain an intermediate 4-ethylpyridine; and carrying out catalytic oxidation to obtain the target product 4-acetylpyridine. According to the method for preparing 4-acetylpyridine, the reaction steps are few, the raw material price is low, and the catalyst used in the oxidation reaction can be recycled, when 4-ethylpyridine is synthesized, after iron powder is added, the problems that in the heat preservation reaction stage, the fluidity of reaction liquid becomes poor, and a stirring paddle is locked are solved by adopting a xylene adding mode; water is removed before rectification, so that the problem of ternary azeotropy of water, pyridine and 4-ethylpyridine is solved; before the oxidation reaction, the conversion rate is obviously improved by vacuumizing oxygen replacement and adopting a micro-positive pressure reaction mode, and the catalyst N-hydroxyphthalimide can be recycled, so that the method has a relatively good application value.