128 results about "Pentanone" patented technology

The invention relates to the technical field of fire extinguishing materials, and discloses an active fire extinguishing microcapsule, a preparation method and application thereof, an ultraviolet curing resin plate and a preparation method thereof. The microcapsule has a core-shell structure, a core material is perfluoro (2-methyl-3-pentanone) (PFMP), and the microcapsule is used as an efficient fire extinguishing agent and is suitable for inhibiting the heat rise rate of an ultraviolet curing polymer in thermal runaway and fire scenes; and the shell layer is a polymer wall material formed by gelatin, has a certain thickness and can be broken at a preset temperature. Through simple condensation, PFMP is used as a core material for microencapsulation, and the microcapsule with specific particle size distribution is prepared, so that the microcapsule can quickly release a fire extinguishing agent under a high-temperature condition, and flames are effectively inhibited.

The invention discloses a preparation method of 6-methyl-5-octylene-2-ketone, and belongs to the technical field of organic synthesis. According to the method, 5-chloro-2-pentanone is taken as a starting raw material, carbonyl protection is carried out with trimethyl orthoformate under the catalysis of acid, then a Grignard reagent is prepared, condensation dehydration is carried out on the Grignard reagent and 2-butanone, deprotection is carried out under the acidic condition, and 6-methyl-5-octylene-2-ketone is prepared with high yield, the raw materials are easy to obtain and low in price, and the reaction can be catalyzed by using a conventional catalyst.

The invention discloses a bio-based gemini quaternary ammonium salt compound as well as a preparation method and application thereof. The bio-based gemini quaternary ammonium salt compound is a compound with a structural formula as shown in a formula I, wherein R1 is selected from one of cyclohexanone, cyclopentanone, acetone, 2-octanone and 2-pentanone; r2 is selected from C4-C24 alkyl groups (except C19 and C21); x is at least one of Cl, I and Br. The bio-based gemini quaternary ammonium salt compound disclosed by the invention takes 5-hydroxymethylfurfural as a raw material, has a furan ring, a quaternary ammonium salt substituent group and a long alkyl chain in the structure and can be used as a corrosion inhibitor, and a quaternary ammonium salt functional group and an alkyl long chain are constructed in the structure and respectively serve as a hydrophilic functional group and a hydrophobic functional group, so that the biological activity of the compound is improved. When the gemini quaternary ammonium salt corrosion inhibitor is in contact with steel (metal), a protective film can be formed on the surface of the steel (metal), so that the effect of protecting the steel (metal) is achieved, the corrosion speed of the steel (metal) is slowed down, and the economic benefit is extremely high; # imgabs0 #

The invention discloses colloid, porous carbon and a preparation method and application thereof. The preparation method of the colloid comprises the following steps: S1, extracting aromatic hydrocarbon-rich oil by adopting a first solvent to obtain a soluble component which is a component A; wherein the first solvent is selected from one or more of o-dichlorobenzene, dipropyl ether and 3-pentanone; s2, the component A is adsorbed to an aluminum oxide chromatographic column, petroleum ether or n-heptane, methylbenzene and a second solvent are sequentially adopted to wash the chromatographic column, then desorbed matter is obtained, and the second solvent is a mixture of methylbenzene and ethyl alcohol. The colloidal pyrrole is high in nitrogen content, and the porous carbon prepared from the colloidal pyrrole is excellent in conductivity.

The invention discloses a mixed fire extinguishing agent and a testing method thereof, and the mixed fire extinguishing agent comprises 2-bromo-3, 3, 3-trifluoropropene and perfluoro-2-methyl-3-pentanone; the test method comprises the following steps: S100, mixing the 2-bromo-3, 3, 3-trifluoropropene and the perfluoro-2-methyl-3-pentanone according to a preset mass ratio, and adding the 2-bromo-3, 3, 3-trifluoropropene and the perfluoro-2-methyl-3-pentanone into the mixture, s200, controllable flames are generated; s300, a mixture of the 2-bromine-3, 3, 3-trifluoropropene and the perfluoro-2-methyl-3-pentanone is adopted to carry out fire extinguishing on the controllable flame, and a mixture of the 2-bromine-3, 3, 3-trifluoropropene and the perfluoro-2-methyl-3-pentanone is adopted to carry out fire extinguishing on the controllable flame And S400, the minimum fire extinguishing concentration of the mixture is measured. The mixed fire extinguishing agent and the testing method thereof have the advantage that the mixed fire extinguishing agent capable of effectively extinguishing fire and the testing method thereof are provided.

The invention provides a preparation method of 2-pentyl-2-cyclopentenone, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: carrying out a first-stage isomerization reaction on 2-pentylidene cyclopentanone and a first composite catalyst in a first atmosphere to obtain an intermediate, carrying out a second-stage isomerization reaction on the intermediate and a second composite catalyst in a second atmosphere, and controlling the volume ratio of nitrogen to hydrogen in the first atmosphere and the second atmosphere to obtain the 2-pentylidene cyclopentanone. In the first-stage isomerization reaction, the conversion rate of converting 2-pentylidene cyclopentanone into 2-pentyl-2-cyclopentenone is increased, and in the second-stage isomerization reaction, the use amount of hydrogen in the second atmosphere is reduced, the temperature of the second-stage isomerization reaction is increased, generation of by-products is inhibited, and the yield of 2-pentylidene cyclopentanone is increased. Further, the yield and the purity of the 2-pentyl-2-cyclopentenone can be improved. According to the preparation method, the first-stage isomerization reaction and the second-stage isomerization reaction are continuous reactions, intermittent reactions are not needed, and the preparation method is more suitable for industrial application.

The invention provides a method for extracting, rectifying and separating an ethano-2-pentanone azeotropic system by using a tetramethylammonium chloride eutectic solvent, and relates to the technical field of extracting, rectifying and separating the ethano-2-pentanone azeotropic system, which comprises the following steps: taking an ethano-2-pentanone mixture as a raw material to be separated; the method comprises the following steps: mixing and stirring a hydrogen bond acceptor and a hydrogen bond donor according to a certain proportion and temperature to obtain the eutectic solvent, firstly heating a material S01 to be separated by a heat exchanger E101 and then entering the middle part of a T101 tower, adjusting a eutectic solvent material flow S02 to a proper temperature and then entering the upper part of the T101 tower, carrying out heat exchange on a tower top ethanol material flow S03, enabling a part of material flow S05 to flow back to the tower top, and carrying out heat exchange on a tower top ethanol material flow S03; according to the method, a specific eutectic solvent is adopted as an extracting agent, an extractive distillation process is matched, an ethano-2-pentanone azeotropic system can be effectively broken, the yields of ethanol and 2-pentanone can reach 99% or above finally, the purities of ethanol and 2-pentanone can reach 99.5% (mass percent) or above finally, and efficient separation is achieved.

The invention belongs to the technical field of synthesis of 5-methyl-2-heptene-4-ketone, and particularly relates to a preparation method of spice 5-methyl-2-heptene-4-ketone, which comprises the following steps: S100: reacting butanone with 2-methylbutyryl chloride under alkaline conditions to obtain an intermediate 3-methyl-2-pentanone; and S200, enabling the intermediate 3-methyl-2-pentanone to react with acetaldehyde under an acidic condition, so as to obtain the spice 5-methyl-2-heptene-4-ketone. The 5-methyl-2-heptene-4-ketone prepared by the method not only has good yield, but also can reduce the production cost and improve the production efficiency.

The invention belongs to the technical field of organic matter preparation, and particularly relates to a preparation method of 2-pentylcyclopentyl-2-ketene. According to the method, methanol is used as a solvent, sulfonic acid type resin doped with lewis acid is used as a catalyst to catalyze the isomerization reaction of 2-pentylidene cyclopentanone, the catalyst and the methanol solvent can jointly promote the isomerization reaction of 2-pentylidene cyclopentanone, and the catalytic efficiency is high, so that the reaction yield is remarkably increased, and the catalyst cost is reduced; in addition, a fixed bed reactor continuous production mode is adopted, waste salt is prevented from being generated when the acid catalyst is quenched by processes such as HCl / HBr / p-toluenesulfonic acid, and methanol is used as a solvent, so that the byproduct dimethyl ether is simply separated from water and the solvent methanol. In addition, when the sulfonic acid type resin doped with the lewis acid is used for catalyzing the isomerization reaction of 2-pentylidene cyclopentanone, the stability is high, and the service life is long.

The invention relates to an insulating flame-retardant automatic fire extinguishing paste and a preparation method thereof. The insulating flame-retardant fire extinguishing patch comprises a bottom film, an adhesive layer and an insulating flame-retardant layer, the insulating flame-retardant layer is prepared from the following components in parts by weight: 20 to 60 parts of perfluoro-2-methyl-3-pentanone microcapsules, 20 to 30 parts of polydimethylsiloxane, 0.1 to 5 parts of magnesium hydroxide, 0.1 to 5 parts of triphenyl phosphate, 0.5 to 5 parts of tributyl phosphate, 0.1 to 5 parts of tris (2-ethylhexyl) phosphate, 0.2 to 5 parts of tris (2, 3-dichloropropyl) phosphate, 0.2 to 5 parts of tetrabromobisphenol A epoxy resin, 0.5 to 3 parts of antimony trioxide and 0.1 to 5 parts of borate. 0.1 to 5 parts of dichlorobromomethane and 0.1 to 5 parts of trichlorobromomethane. The insulating flame-retardant fire extinguishing paste is easy to install, does not need maintenance, actively extinguishes fire when a fire occurs in the initial stage, can achieve the effect of multiple times of fire extinguishing, can effectively prevent reburning and fire expansion, and is safe, green and environmentally friendly.

The invention belongs to the technical field of pesticides and chemical engineering, and particularly relates to a green preparation method of metconazole, which comprises the following steps: under the catalysis of alkali A, carrying out condensation reaction on cyclopentanone and benzaldehyde to obtain alpha, beta-unsaturated ketone; under the catalysis of alkali B, the alpha, beta-unsaturated ketone reacts with a methylation reagent to obtain double methylated alpha, beta-unsaturated ketone; under the action of a catalyst, the double-methylated alpha, beta-unsaturated ketone reacts with hydrogen to obtain 2, 2-dimethyl-5-benzyl cyclopentanone of which the double bonds are reduced; and reacting the 2, 2-dimethyl-5-benzyl cyclopentanone with a chlorination reagent under the action of a catalyst to obtain the 2, 2-dimethyl-5-(4-chlorobenzyl) cyclopentanone. According to the invention, cyclopentanone is used as a raw material to synthesize 2, 2-dimethyl-5-(4-chlorobenzyl) cyclopentanone through four-step simple reactions, metconazole is obtained through epoxidation and ring-opening substitution, and metconazole is finally obtained through recrystallization, so that the method has the advantages of cheap and easily available raw materials, simple process, environmental protection and the like, is suitable for long-term industrial development, and has wide application prospects. Good application prospects are realized.

Fire protection structure, at least comprising or consisting of: a first case and a second case; where the first shell surrounds or encloses an interior space, the interior space is suitable for accommodating a cable, a conduit or a pipe or sections thereof; wherein the first shell contains or consists of at least one aerogel; wherein the second shell surrounds or encloses the first shell; wherein the second shell contains or consists of a material that expands when exposed to heat, preferably a fire-resistant material; wherein the heat-expandable material is expandable graphite, a combination of a first coating material and a primer, or a combination of the first coating material and a second coating material and the primer; wherein the primer contains or consists of a primer, a hardener and a thinner, the primer contains: Xylene (CAS No. 1330-20-7); Hydrocarbons, C9, Aromatics (CAS No. 64742-95-6); Reaction product: Bisphenol-A-epichlorohydrin resins with an average molecular weight of 700 to 1100 (CAS No. 25068-38-6); Butan-1-ol (CAS No. 71-36-3); Trizinc bis(orthophosphate) (CAS No. 7779-90-0); Ethylbenzene (CAS No. 100-41-4); 4-Hydroxy-4-methyl-pentan-2-one (CAS No. 123-42-2); Solvent naphtha (petroleum), lightly flavored (CAS No. 64742-95-6); and Silicon dioxide (CAS No. 7631-86-9); the hardener contains: Hexamethylene-1,6-diisocyanate, homopolymer (CAS No. 28182-81-2); Hydrocarbons, C9, Aromatics (CAS No. 64742-95-6); Hexamethylene-1,6-diisocyanate (CAS No. 822-06-0); Dimethylbis[(1-oxoneodecyl)oxy]stannan (CAS No. 68928-76-7); and n-Butyl acetate (CAS No. 123-86-4); and containing the thinner: Xylene (CAS No. 1330-20-7); Butan-1-ol (CAS No. 71-36-3); Ethylbenzene (CAS No. 100-41-4); and n-Butyl acetate (CAS No. 123-86-4.

The invention belongs to the technical field of fine chemical engineering, and particularly relates to a process method for producing 3-pentanone by dehydrogenation of 3-pentanol. According to the method, 3-pentanol is used as a raw material, a supported copper-based catalyst is used, 3-pentanol is fed into a dehydrogenation reactor for dehydrogenation reaction, 3-pentanol reaction liquid is subjected to continuous rectification, light components are removed in a light component removal tower, and high-purity 3-pentanone is obtained at the top of the heavy component removal tower. The specific catalyst is adopted for preparing the 3-pentanone through dehydrogenation of the 3-pentanol, so that the dehydrogenation efficiency of the 3-pentanol is remarkably improved, and the selectivity of the 3-pentanone is 99.5% or above, so that the single-pass preparation of the 3-pentanone from the 3-pentanol is remarkably improved, and meanwhile, the production energy consumption cost is greatly reduced. According to the method, normal-pressure multi-tower continuous rectification is adopted, separation and purification of the product are achieved, and the 3-pentanone product meeting the standard is obtained.

A preparation method of N '-((2S, 3S)-2-(benzyloxy) pent-3-yl) formylhydrazine oxalate enzyme belongs to the field of medical intermediates, and comprises the following steps: step 1, preparing a buffer solution of a compound enzyme preparation; step 2, adding (2S)-2-benzyloxy-3-pentanone into a solvent A, and then adding a buffer solution of the compound enzyme preparation for reaction; 3, filtering, and carrying out an activation reaction on the filtrate; 4, filtering, removing the solvent, adding the obtained solid into a solvent B, and then adding formylhydrazine for reaction; 5, filtering, removing the solvent, adding the obtained solid into a solvent C, and then adding oxalic acid for reaction; and 6, drying the solid obtained by filtering to obtain the N '-((2S, 3S)-2-(benzyloxy) pent-3-yl) formylhydrazine oxalate. According to the method, the yield of the N '-((2S, 3S)-2-(benzyloxy) pent-3-yl) formylhydrazine oxalate can be increased, and the production cost is effectively reduced.

The present invention provides a 3-chloro-5-hydroxy-2-pentanone synthesis method, which comprises: mixing furfural, water and hydrogen, introducing the mixture into a fixed bed reactor filled with a first catalyst, and sequentially carrying out a hydroxylation reaction, a 1, 4-hydrogenation reaction and a ring-opening reaction to obtain a 5-hydroxy-3-ene-2-pentanone crude product; and mixing the 5-hydroxy-3-ene-2-pentanone crude product and hydrogen chloride gas, introducing the mixture into a fixed bed reactor filled with a second catalyst, and carrying out an addition reaction to obtain the 3-chloro-5-hydroxy-2-pentanone. The preparation method has the following advantages: the raw material furfural is low in price, and meanwhile, a relatively dangerous oxidant is prevented from being used; the process route is simple, the yield is high, and green chemical requirements are met; a fixed bed reactor is adopted for continuous catalytic preparation, the technological process is uninterrupted, and the automation degree is high; the bottleneck problem of scale limitation of kettle type reaction is solved, the reaction time is prolonged, the reaction efficiency is improved, and side reaction is inhibited to the greatest extent.

This invention discloses a method for producing 4-methyl-2-pentanone, which is implemented using a 4-methyl-2-pentanone production apparatus. The apparatus includes a reactive distillation column, a condenser connected to the top of the reactive distillation column, and a reboiler connected to the bottom of the column. The reactive distillation column has a rectification section, a reaction section, and a stripping section arranged sequentially from top to bottom. During operation, a catalyst is placed in the reaction section, and 4-methyl-2-pentanol is introduced into the reaction section. The temperature of the reaction section is controlled at 180–280°C. The gas phase produced by the reaction is condensed by the condenser to produce 4-methyl-2-pentanone. This production method features high conversion rate, stable product quality, and low energy consumption.

The invention belongs to the technical field of aliphatic ketone preparation, and particularly relates to a preparation method and device of 2-pentylidene cyclopentanone. The method comprises the following steps: by taking activated solid alkali as a catalyst, carrying out catalytic synthesis reaction on cyclopentanone and n-valeraldehyde in a fixed bed reactor to obtain a catalytic synthesis reaction solution; the solid alkali comprises a carrier and an active component loaded on the carrier; the catalytic synthesis reaction liquid is separated and purified through a concentration tower, and 2-pentylidene cyclopentanone and fractions containing n-valeraldehyde, cyclopentanone and water are obtained respectively; and carrying out oil-water separation on the fraction containing n-valeraldehyde, cyclopentanone and water to obtain n-valeraldehyde and cyclopentanone, and circularly carrying out catalytic synthesis reaction on the n-valeraldehyde and cyclopentanone as raw materials. The activated solid alkali is used as the catalyst, the use of an alkaline aqueous solution is avoided, the discharge of wastewater is reduced, the raw material conversion rate is high, and the product yield is high.

The invention discloses an exhaled gas VOC (volatile organic compound) marker for detecting inflammatory bowel diseases and a detection system thereof. The marker is a combination of one or more of the following components: methyl propyl sulfide, propionaldehyde, cyclohexanone, allyl methyl sulfide, octanal, 2-pentanone, phenol, butyric acid, propionic acid and 3-methylheptane. The detection system comprises an exhaled air sampling module, a sample preprocessing module, a detection analysis module and a data analysis module. The marker provided by the invention has the advantages of high specificity and good stability, can realize accurate noninvasive diagnosis of IBD, and can assist in realizing early screening and dynamic monitoring in a clinical environment.

The invention discloses a method for separating 2-pentanone and 2-pentanol by using a symmetric conjugated column [5] arene derivative crystalline non-porous material, which is characterized in that the symmetric conjugated column [5] arene derivative crystalline non-porous material is used as an adsorbent to selectively adsorb and separate 2-pentanone from a 2-pentanone / 2-pentanol mixture so as to realize adsorption separation of 2-pentanone and 2-pentanol. Industrial rectification is not needed in the adsorption separation process, the energy consumption is low, and the separation cost of the 2-pentanone and the 2-pentanol is reduced. The selected crystalline non-porous material is simple to prepare, has good economic feasibility and stability, and is short in adsorption separation time, low in equipment requirement and good in separation effect.

The invention discloses a photoelectric functional material 2-(4-fluorophenyl) propionic acid-2-propenyl ester synthesis method, which comprises: 1, adding alkaline earth metal, an initiator and a solvent I into a reaction bottle, carrying out heating reflux in an inert gas atmosphere, firstly dropwise adding a p-bromofluorobenzene solution, observing the change of the reaction solution, determining the initiation success, then dropwise adding the residual p-bromofluorobenzene solution, and carrying out heating reflux in an inert gas atmosphere, adding dropwise under a controlled reflux condition, carrying out heat preservation and stirring after dropwise adding, then cooling in an inert atmosphere, dropwise adding a 3-pentanone solution, controlling the temperature until the reaction is finished, and carrying out post-treatment to obtain an intermediate 1; and 2, dissolving the intermediate 1 in a solvent II, cooling in a nitrogen atmosphere, dropwise adding an alkyl metal solution, heating after dropwise adding, cooling, dropwise adding methacrylic anhydride, controlling the temperature until the reaction is finished, adding a polymerization inhibitor into the reaction liquid, and carrying out post-treatment to obtain the 2-(4-fluorophenyl) propionic acid-2-propenyl ester. According to the invention, the cheap p-bromofluorobenzene is used as the raw material, so that the material cost is saved, and the 2-(4-fluorophenyl) propionic acid-2-propenyl ester with high purity and high yield is prepared.

This invention relates to "an efficient and safe method for synthesizing perfluoropentanone," belonging to the field of organic chemical synthesis. The method for synthesizing perfluoropentanone is characterized by the following steps: under the action of hexafluoropropylene CF2=CF-CF3, fluorophosgene CF2O, and trifluorobromomethane CF3Br, perfluoropentanone (C5F) is generated in the gas phase. 10 O. The raw materials of this invention are inexpensive and readily available; the product separation and purification are simple; it is easy to industrialize; and it produces less industrial waste.

The application discloses a preparation method of an amido pyrazole compound and a method for preparing sildenafil by using the same. The amido pyrazole compound is shown as formula I. The compound of formula I is prepared by using 2-pentanone as an industrial chemical, and can be used for synthesizing sildenafil which is a selective inhibitor of type 5 phosphodiesterase (PDE5). The method has the advantages of easy availability of raw materials, simple operation, avoidance of nitration reaction, avoidance of safety hidden dangers caused by the nitration reaction from a technical source, and avoidance of environmental protection pressure caused by a large amount of nitration waste liquid, and is suitable for development into a green and sustainable production process of sildenafil bulk drug.

The present invention provides a preparation method of a posaconazole intermediate. In this method, 3-pentanone is used as the starting material, and the posaconazole intermediate is prepared through an asymmetric catalytic oxidation reaction, a substitution reaction and an asymmetric reductive amination reaction. The product obtained by this method has high purity and good yield. The preparation method has fewer steps, the raw materials are cheap and easily available, the operation is simple, the total yield is high, and it is more suitable for industrial production.

This invention belongs to the field of chemical technology, specifically relating to a method for preparing glutaric acid. The method includes: reacting cyclopentanone with an oxygen-containing gas in the presence of a solvent and a catalyst, and separating the glutaric acid; the contact is carried out in the presence of an auxiliary, wherein the auxiliary is a C5-C6 alcohol and / or a C6 ketone. This invention, by adding a suitable auxiliary to the cyclopentanone oxidation catalytic reaction, improves the conversion rate of cyclopentanone, enhances the selectivity of glutaric acid, reduces the occurrence of side reactions, and alleviates the burden of impurities in the synthesis liquid, achieving better technical results.

The application relates to the technical field of alpha-olefin preparation, and discloses a method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanone, which comprises the following steps: (1) mixing 4-methyl-2-pentanone with hydrogen in the presence of a hydrogenation catalyst to perform a hydrogenation reaction, so as to obtain a 4-methyl-2-pentanol-containing stream; (2) performing ketone removal on the 4-methyl-2-pentanol-containing stream, so as to obtain 4-methyl-2-pentanone and 4-methyl-2-pentanol crude products; and (3) performing dehydration reaction on the 4-methyl-2-pentanol crude products obtained in the step (2) in the presence of a dehydration catalyst, so as to obtain a 4-methyl-1-pentene-containing stream. The method for preparing 4-methyl-1-pentene from 4-methyl-2-pentanone can be simply and effectively used for preparing 4-methyl-1-pentene products, 4-methyl-2-pentanone raw materials are easy to obtain, the reaction conditions are relatively mild, the product distribution is simple, and high-purity 4-methyl-1-pentene products can be prepared.

Described herein are perfuming compositions and perfumed consumer products including, as perfuming ingredients, cyclopentanone compounds of formulain a form of any one of its stereoisomers or a mixture thereof, where n represents 1.

The invention discloses a carbonyl reductase mutant and application of the carbonyl reductase mutant in synthesis of a posaconazole intermediate. The mutant protein is a non-natural protein, and the mutant protein can significantly improve the activity of catalyzing reduction of carbonyl in (S)-2-benzyloxy-3-pentanone to generate R-configuration alcohol. When the carbonyl reductase mutant strain with improved activity is applied to the production process of a posaconazole intermediate, 100-200 g / L of a substrate can be completely converted, and (2S, 3R)-2-benzyloxy-3-pentanol is generated.

The invention relates to a method for a palladium-catalyzed cyclization extension reaction of butadienes. Specifically, under the condition that tert-butyl nitrite is oxidized under the catalysis of palladium, the cyclopentanone compound is obtained through a ring extension reaction of butyl fulvene and water. According to the invention, green and rich water is used as a raw material, and a series of cyclopentanone compounds are obtained under mild conditions.

The application belongs to the technical field of organic chemical synthesis and heterogeneous catalysis, and particularly relates to a catalyst for preparing 2,4-dimethyl-3-pentanone from isobutyric acid or isobutyric anhydride and a preparation method thereof. The application overcomes key technical bottlenecks in the existing gas-phase ketonization reaction, such as serious cracking side reactions, quick deactivation of the catalyst due to carbon deposition, and low selectivity of the target product. The application provides a method for efficiently preparing 2,4-dimethyl-3-pentanone from isobutyric acid or isobutyric anhydride. The method innovatively constructs a modified HZSM-5 molecular sieve catalyst with a micropore-mesopore multi-level pore structure, and introduces specific metal oxide active components to construct acid-base synergistic active centers, thereby realizing directional regulation of the reaction path. The method not only significantly inhibits the competitive monomolecular cracking reaction, greatly improves the selectivity of the bimolecular coupling ketonization reaction for generating 2,4-dimethyl-3-pentanone, but also effectively eliminates the diffusion resistance of macromolecular products by using mesoporous channels, thereby fundamentally solving the problem of easy carbon deposition and deactivation of the catalyst, and having excellent industrial application prospects and technical progress.

The invention belongs to the technical field of organic synthesis, and provides a method for synchronously preparing 3-methyl-2-butanone and 3-pentanone, butanone, methanol, ion exchange resin and a catalyst are mixed for alcohol ketone condensation reaction, and 3-methyl-2-butanone and 3-pentanone are obtained at the same time. Methanol and butanone are used as raw materials and react under the action of ion exchange resin and an activated carbon supported metal catalyst. According to the method, directional control of the molar ratio of 3-methyl-2-butanone to 3-pentanone is realized by accurately regulating and controlling reaction conditions, and generation of other by-products in the reaction process is relatively low. Specifically, when anion exchange resin is added into reactants, alpha-H at the edge of butanone is strong in acidity and small in steric hindrance, so that 3-pentanone is a main product (selectivity is greater than or equal to 75%); when cation exchange resin is added into reactants, alpha-H in butanone is good in stability, and 3-methyl-2-butanone is a main product (selectivity is greater than or equal to 70%).