352 results about "Decarboxylation" patented technology

The invention belongs to the field of organic synthetic chemistry, and relates to a preparation method of melatonin and meerythrine indole derivatives and compounds. Specifically, the indole derivative is efficiently synthesized by taking arylamine and carboxylic acid as raw materials through a one-pot two-step reaction in the presence of catalysis of ferric chloride hexahydrate (FeCl3. 6H2O), a ligand, a diazotization reagent, an additive and a solvent under the conditions of visible light irradiation, inert atmosphere and room temperature. According to the method, visible light induced iron-based LMCT catalysis and iron lewis acid catalysis functions are integrated, and efficient integration of diazotization, decarboxylation, free radical coupling and cyclization reaction is achieved. The method has the advantages that raw materials are cheap and easy to obtain, reaction conditions are mild, substrate applicability is wide, functional group compatibility is good, operation is easy, convenient and safe, and environment friendliness is achieved, gram-level scale preparation can be achieved, and a green and efficient synthesis path is provided for indole compounds with biological activity such as melatonin and meerythrine.

The invention belongs to the technical field of separation of drug intermediates, and particularly relates to a control method for a process impurity 2-ethyl valeric acid (EP-B) in preparation of valproic acid or sodium valproate by a diethyl malonate method. According to the method disclosed by the invention, the content of 2-ethyl-2-propylmalonic acid process impurities in dipropylmalonic acid is controlled, so that the content of 2-ethylvaleric acid (EP-B) which is a process impurity in valproic acid or sodium valproate is accurately controlled; adding a polar solvent into the dipropylmalonic acid crude product, heating, pulping for a certain time, cooling, filtering and drying to obtain a high-purity dipropylmalonic acid refined product; high-purity valproic acid (RRT is equal to 1.00) is prepared through decarboxylation of the dipropyl malonic acid fine product, and the purity is 99.779%; 0.020% of 2-ethyl valeric acid (RRT is equal to 0.90); and valeric acid (RRT = 0.77), 0.039%. The valproic acid product quality meets the requirements of European Pharmacopoeia. According to the method, the problems of quality control and process evaluation of valproic acid or sodium valproate prepared by a diethyl malonate method are solved.

The invention relates to a method for preparing high-molecular-weight polyethylene furandicarboxylate by a one-step method, and belongs to the technical field of bio-based polyester materials. The method comprises the following steps: weighing raw materials including 2, 5-furandicarboxylic acid, ethylene glycol, an end group regulator, a protective agent, a decarboxylation inhibitor and a catalyst, mixing and adding into a reaction container, introducing nitrogen, maintaining the pressure of the nitrogen in the reaction container to be 50-150 kPa, carrying out esterification reaction, heating and vacuumizing until the pressure is less than or equal to 50 Pa after the esterification reaction is completed, and carrying out polycondensation reaction to obtain the 2, 5-furandicarboxylic acid. And carrying out extrusion and drying so as to obtain the high-molecular-weight polyethylene furandicarboxylate, wherein the high-molecular-weight polyethylene furandicarboxylate is obtained. According to the method, the FDCA conversion rate is larger than or equal to 98%, the number-average molecular weight of the obtained product is larger than or equal to 32 kg / mol, no heavy metal residues exist, and the method is suitable for large-scale production of high-end bio-based packaging materials.

The invention belongs to the technical field of separation of drug intermediates, and particularly relates to a method for preparing a high-purity dipropylmalonic acid refined product by adding a polar solvent into a dipropylmalonic acid crude product, heating, pulping for a certain time, cooling, filtering and drying. Decarboxylating the refined dipropylmalonic acid product to obtain high-purity valproic acid; distilling the filtrate to recover the polar solvent to obtain 2-methyl-2-propylmalonic acid, and carrying out decarboxylation on the 2-methyl-2-propylmalonic acid to obtain 2-methylpentanoic acid; 2-methylvaleric acid is used as a perfume additive. According to the method disclosed by the invention, the process impurity 2-methyl-2-propylmalonic acid in dipropylmalonic acid is separated, and the process impurity 2-methylvaleric acid (EP-L) in valproic acid or sodium valproate is precisely separated; the quality of the valproic acid product prepared by the method disclosed by the invention meets the requirements of European Pharmacopoeia EP-11 (2023). According to the invention, the problems of quality control and process evaluation of valproic acid or sodium valproate prepared by a dimethyl malonate method are solved.

The invention provides a preparation method of an omariglitazone intermediate, which comprises the following steps: by taking p-halogenated benzaldehyde as a raw material, carrying out aldol condensation reaction, hydrolysis, decarboxylation, reduction, ring closing and the like to obtain an intermediate as shown in a formula 9, carrying out catalytic reaction, reduction reaction, ring closing and the like to obtain an intermediate as shown in a formula 13, and finally hydrolyzing to obtain a target product omariglitazone intermediate A. According to the invention, links of precious metal use and chiral resolution (key steps influencing cost and yield) in the prior art are avoided, and a method for synthesizing a single configuration through a chemical method is adopted, so that the yield is greatly improved, and the production cost is greatly reduced; meanwhile, a synthesis route is broken through, a target product is synthesized through cheap initial materials, and post-treatment is simpler and more controllable.

The invention relates to a synthesis method of milobalin or acid salt thereof, and belongs to the technical field of medicine synthesis. In order to solve the problem that chiral resolution needs to be adopted in the prior art, the invention provides a synthesis method of miloabalin or an acid salt thereof, which comprises the following steps: under the action of an organic strong base, carrying out Michael addition reaction on a compound shown as a formula III and acetonitrile in a non-polar organic solvent at a low temperature of-50 DEG C or below to obtain an intermediate product; under the alkaline condition, the intermediate product is subjected to an oxidation reaction and a hydrolysis reaction under the action of an oxidizing agent, after the reaction is finished, an intermediate product is obtained through acidification, and the intermediate product is subjected to a high-temperature decarboxylation reaction in an aprotic solvent to obtain a compound of a formula VI; and carrying out Hofmann degradation reaction on the compound of formula VI to obtain the compound of formula I miloabalin or miloabalin acid salt. The method has the advantages of high stereoselectivity, no need of chiral resolution operation, avoidance of the problem of large material loss caused by resolution, high chiral purity and high yield.

The invention discloses a salicylic acid decarboxylase mutant and application of the salicylic acid decarboxylase mutant in degradation of salicylic acid. The mutant is obtained by carrying out site-specific modification on salicylic acid decarboxylase NahG, and specifically, valine at the 46th site, tyrosine at the 380th site and leucine at the 382nd site of an amino acid sequence shown in SEQ ID NO.2 are mutated into cysteine, phenylalanine and phenylalanine at the same time. The mutant shows remarkably improved catalytic efficiency, and salicylic acid can be efficiently and thoroughly decarboxylated and converted into catechol under mild conditions. The invention also provides a coding gene, a recombinant vector and an engineering bacterium of the mutant. The mutant not only can be used for efficient bioremediation of salicylic acid pollution, but also can effectively break through and accelerate a naphthalene catabolism pathway due to the characteristic of directionally generating catechol, and has important application value in the fields of environmental pollution abatement and biological catalysis.

The invention discloses a ZnTi-LDH modified UiO-66 nano composite material modified electrode rich in defects, a preparation method of the electrode and application of the electrode to detection of glyphosate pesticides. The preparation method comprises the following steps: firstly, treating UiO-66 by adopting a surface controlled decarboxylation defect technology to obtain defect-rich UiO-66, then preparing ZnTi-LDH on the surface of the UiO-66 in situ by adopting a hydrothermal method to obtain the ZnTi-LDH-coated D-UiO-66 heterostructure, and the structure can provide a large specific surface area and rich active sites, simultaneously contains Zr and Ti two metal types capable of complexing with organic phosphine molecules, and can be used for preparing a high-specific-surface-area catalyst. The adsorption and capture of the catalyst on an analyte are greatly improved, and the sensing analysis performance of a corresponding sensor on an organic phosphine pesticide is improved. An electrochemical sensing platform constructed on the basis of the ZnTi-LDH-coated D-UiO-66 nanocomposite modified electrode obtains a wide detection range (0.05-50 [mu] mol L1), a low detection limit of 0.19 [mu] mol / L (S / N = 3) and high sensitivity (1.220 [mu] A.[ mu] mol / L) when glyphosate is detected, and has good selectivity, reproducibility and stability.

The application relates to the technical field of catalysts and compound preparation, in particular to a metal-modified zeolite catalyst and a method for catalyzing lactone compounds to generate terminal olefins. ‑ SiO2; wherein the metal M is selected from any one of Ti, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, W, Ta and Hf; in the provided metal-modified zeolite catalyst, metal atoms are arranged on the skeleton end points of a zeolite molecular sieve to form a monatomic catalyst; on one hand, the obtained catalyst has Lewis metal sites, can be beneficial to catalyzing lactone compounds to realize decarboxylation, and can ensure that the lactone compounds can be directly catalyzed to generate terminal olefins, and can be widely applied.

The invention discloses a preparation method of 3-quinuclidinone hydrochloride, which comprises the following steps: carrying out temperature control reaction on 4-picolinic acid and chloroacetic acid under alkaline water conditions to obtain an aqueous solution of a compound a, and directly entering the next reaction without post-treatment after the reaction is finished; adding a reducing agent alkaline water system into the aqueous solution of the compound a, controlling the temperature to react, controlling the temperature to adjust the pH value to 5-5.5 after the reaction is finished, extracting with n-butyl alcohol, and drying to obtain an n-butyl alcohol solution of a compound b, and directly entering the next reaction step; wherein the reducing agent is one of sodium borohydride and potassium borohydride; dropwise adding thionyl chloride into an n-butyl alcohol solution of the compound b, controlling the temperature to react after dropwise adding is ended, and concentrating to remove the solvent and unreacted thionyl chloride after the reaction is ended, so as to obtain a compound c; carrying out Dieckmann condensation reaction on the compound c at controlled temperature under the condition of organic alkali by using toluene as a solvent, carrying out hydrochloric acid quenching reaction after the reaction is finished, and directly carrying out next-step reaction after extracting and removing impurities from a water phase containing a hydrochloride solution of a compound d by using toluene; and carrying out a decarboxylation reaction on the compound d in a hydrochloric acid aqueous solution at controlled temperature, after the reaction is finished, adjusting the pH value to 10-13, extracting, and salifying to obtain a target compound TM, namely 3-quinuclidinone hydrochloride. The preparation method of 3-quinuclidinone hydrochloride provided by the invention has the advantages of economical and easily available raw materials, mild reaction conditions, efficient reaction, simple operation and low cost, and is suitable for industrial application.

The invention discloses application of bismuth vanadium tetraoxide as a photocatalyst in preparation of allantoin. According to the method, a decahedral single crystal micron material bismuth vanadium tetroxide is used as a photocatalyst, uric acid is used as a substrate, a photocatalytic reaction is performed under the irradiation of visible light, and uric acid is oxidized, hydrolyzed, decarboxylated and converted into allantoin; compared with a traditional chemical synthesis method, the method has the advantages that the bismuth vanadium tetraoxide serves as a photocatalyst, uric acid is converted into allantoin through photocatalytic reaction, selective activation of chemical bonds is achieved through directional regulation and control of photo-induced electron-hole pairs, and the method is mild in reaction condition, low in energy consumption and the like.

The application belongs to the technical field of preparation and application of spermidine, and particularly relates to application of fusarium NF01 in preparation of spermidine and catalysis of lignite liquefaction. The fusarium NF01 is fusarium strain Fusarium sp. NF01. The application finds that the fusarium strain Fusarium sp. NF01 can secrete spermidine synthetase, and then catalyze putrescine and decarboxylated S-adenosyl methionine to biosynthesize spermidine through the spermidine synthetase, so that the spermidine acts on lignite, and then the lignite is liquefied, which can promote the technical progress and application expansion in the field of coal development.

The application belongs to the technical field of compound synthesis, and particularly relates to an alpha-ketoamide derivative and a preparation method thereof, wherein the preparation method of the alpha-ketoamide derivative comprises the following steps: S1, first, a graphite carbon rod electrode and a platinum sheet electrode are respectively assembled on two sides of a 10mL three-port glass bottle; S2, then, a magnetic son is added into the three-port glass bottle, the bottle mouths on two sides are sealed, the three-port glass bottle is transferred to a glove box for feeding, and benzoylformic acid, morpholine and 10mol% of ferrocene in 4mL hexafluoroisopropanol are sequentially added; S3, after the feeding is completed, the last bottle mouth of the three-port glass bottle is sealed, and a constant current of 3mA is introduced for electrolysis. The application realizes the amination reaction of alpha-keto acid by using an electrocatalytic decarboxylation strategy, selectively synthesizes alpha-ketoamide derivatives, and the reaction is suitable for primary amine compounds, secondary amine compounds, is also suitable for aromatic and aliphatic alpha-keto acids, and excellent functional group tolerance is exhibited.

The invention relates to the technical field of cosmetics, in particular to a skin repairing composition for whitening and resisting light damage and a preparation method. The composition comprises polypeptides such as acetyl tetrapeptide-11, glutathione, decarboxylated carnosine, tripeptide-1 and the like, the effects of whitening and brightening the skin, resisting light aging and repairing the skin are achieved through multi-way, multi-azimuth and multi-target combined action and mutual cooperation, and the effects of improving the skin quality and repairing the skin can be better achieved. The composition disclosed by the invention can be widely applied to various cosmetics.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to lithium carboxylate as well as a preparation method and application thereof. The carboxylic acid lithium salt provided by the invention has a monoclinic system structure, and the space group is P21 / c; the purity of the lithium carboxylate is greater than or equal to 99.7%. The carboxylic acid lithium salt has a complete crystal structure, relatively high purity and low lithium removal potential, and no residue is generated when the carboxylic acid lithium salt is used as the positive electrode lithium supplement agent. The lithium carboxylate provided by the invention has high purity, crystal integrity and excellent electrochemical performance, and reaches the standard of a power battery additive; the positive electrode material prepared by using the carboxylic acid lithium salt provided by the invention as a positive electrode lithium supplement agent has excellent physical and chemical properties and environmental friendliness, irreversible decarboxylation lithium release can be realized through a Kolbe electrolytic reaction, and active lithium loss in the first cycle is effectively compensated; and when applied to the lithium ion battery, the lithium ion battery has relatively low decomposition working voltage and stability.

A method to produce a mixture comprising poacic acid (X) and poacidiene (Y) and the resulting product-by-process. The method includes the steps of subjecting a solution of ferulic acid to a free-radical coupling reaction to yield an intermediate mixture comprising ferulic acid dehydrodimers and decarboxylating the intermediate mixture to yield a product mixture containing poacic acid (X) and poacidiene (Y).

The invention relates to the field of chemical production, and discloses a method for preparing 1, 3-cyclohexanedione. The method comprises the following steps: 1, dissolving a raw material A in a solvent, adding a raw material B into a constant-pressure dropping funnel, and dropwise adding the raw material B into a reaction system; continuously stirring and reacting at room temperature for 1 hour after dropwise adding; 2, after the reaction is finished, heating to 50 DEG C, adding the raw material C into a constant-pressure dropping funnel, and dropwise adding the raw material C into a reaction system; after dropwise adding, heating to reflux, continuously stirring and reacting for 6 hours, and extracting by using dichloromethane; sequentially washing the organic extract twice with water, a sodium bicarbonate solution and saline water, drying on anhydrous sodium sulfate, and finally removing the solvent to obtain a cyclization product; and 3, dropwise adding hydrochloric acid into the cyclization product, carrying out decarboxylation reaction, concentrating under reduced pressure to remove low-boiling-point byproducts, cooling to separate out the product, centrifuging, leaching with a small amount of ice water, pulping with ethyl acetate, filtering, and drying to obtain the 1, 3-cyclohexanedione product.

The present invention belongs to the technical field of organic chemical synthesis and discloses a method for preparing asymmetric ketone compounds. This invention, for the first time, achieves the denitrogenation and decarboxylation coupling of vinyl azide with alkyl carboxylates / Katritz salts in the absence of a photocatalyst, filling a gap in the prior art. The method of the present invention features mild process conditions, a short flow, simple steps, and a wide range of substrate applicability, meeting industrial production requirements. Research has found that the product yield can reach as high as 88%, and the resulting ketone compounds have broad application prospects in organic synthesis and drug development. Therefore, the present invention has significant application value.

The invention discloses a collagen peptide composition with a skin saccharification resisting effect and a preparation method of the collagen peptide composition, and belongs to the technical field of health care products. The composition is prepared from the following raw materials in parts by mass: 50-60 parts of collagen peptide, 9-15 parts of decarboxylated carnosine, 5-8 parts of peony peptide, 2-4 parts of fucoxanthol, 5-8 parts of tricholoma lobayense heim polysaccharide, 1-2 parts of sesamin and 3-7 parts of cyclodextrin. The collagen peptide composition is prepared through a reasonable material compounding agent inclusion technology, the anti-saccharification activity of the collagen peptide composition is remarkably improved, and a better scheme is provided for resisting skin saccharification.

The present invention provides a method for producing biodiesel fuel containing saturated hydrocarbons as a main component under relatively mild conditions using vegetable oils or animal fats as a raw material. [Solution] This is a method for producing biodiesel fuel from vegetable oils or animal fats, comprising a decarboxylation step in which carbon dioxide is removed from ester groups in the vegetable oils or animal fats using a decarboxylation catalyst to produce hydrocarbons, and a hydrogenation step in which the resulting hydrocarbons are hydrogenated using a hydrogenation catalyst to produce diesel fuel consisting of saturated hydrocarbons, wherein the decarboxylation step and the hydrogenation step are carried out in the stated order, and each of the decarboxylation step and the hydrogenation step is carried out under a pressure of 0.2 MPa or less.

This invention relates to the field of organic synthesis technology, specifically disclosing a method for preparing 1H-imidazolium-4-carboxylic acid based on a supported copper-based catalyst. The method includes the following steps: preparing a supported copper-based catalyst; adding imidazolium-4,5-dicarboxylic acid and a solvent to a reaction flask, stirring and heating, then adding the catalyst, performing a first stirring reaction, followed by slow heating and a second stirring reaction, monitoring the reaction progress until the reactants have reacted completely, and cooling to room temperature; adding deionized water to the reaction solution, stirring and washing, then cooling to room temperature, filtering the reaction solution, washing the precipitate, and drying to obtain the target product, 1H-imidazolium-4-carboxylic acid. This invention uses imidazolium-4,5-dicarboxylic acid as the starting material, and synthesizes the target product through a decarboxylation reaction under a self-made catalyst. The reaction conditions are mild, the process is simple and easy to control, with few side reactions and high safety, significantly improving the purity and yield of the product.

The application belongs to the field of organic synthesis chemistry and relates to a method for preparing alkyl-substituted glycine derivatives by using a visible light-driven decarboxylation alkylation reaction. The method comprises the following steps: mixing glycine derivatives, N-hydroxyphthalimide (NHPI) ester, 2D-COF-4 and an organic solvent, reacting under a blue LED lamp for 24 hours in an argon environment, and obtaining alkyl-substituted glycine derivatives. The method avoids the use of noble metal photocatalysts, the heterogeneous photosensitizer in the reaction is easy to recycle and reuse, the scope of the substrate is wide, and the functional group compatibility is good; the method can be successfully applied to a kilogram-scale amplification experiment, has a good industrial application prospect, and uses a green solvent, ethanol, which is conducive to reducing production cost and production risk and meets the requirements of developing green and environment-friendly chemistry.

The present application relates to a kind of preparation methods and systems of electronic grade dimethyl carbonate prepared from dimethyl oxalate, the method comprises the following steps: dimethyl oxalate is preheated and sent into decarboxylation reactor to carry out decarboxylation reaction, carbon monoxide, dimethyl carbonate and other light components are extracted from the top of decarboxylation reactor, and heavy components are extracted from the bottom of decarboxylation reactor;Carbon monoxide, dimethyl carbonate and other light components extracted are separated after gas-liquid, and liquid phase dimethyl carbonate is sent into rectifying column to carry out rectification purification;Electronic grade dimethyl carbonate product is obtained by crystallization purification in refrigeration crystallization device after rectification, and crystallization mother liquor returns rectifying column;Decarboxylation reactor is three-stage reaction tower, and rectifying section, reaction section, stripping section are sequentially from top to bottom.The present application is completely reacted by the design of three-stage decarboxylation reactor;Heavy components generated are extracted in real time, and catalyst stability is high;Electronic grade DMC is prepared by using rectifying column coupled with crystallization tower, and the yield of DMC is significantly improved.

A method includes exposing a composition comprising at least one fluorinated carboxylic acid to at least one degrading agent under conditions effective to decarboxylate at least 10% of the at least one fluorinated carboxylic acid. The at least one fluorinated carboxylic acid is selected from the group consisting of a perfluoroalkyl carboxylic acid, a perfluoroether carboxylic acid, and combinations thereof. A degradation composition includes a fluoropolymer, at least one fluorinated carboxylic acid, and at least one degradation agent.

The present invention provides a novel room-temperature extraction system and method for cannabis and hemp, utilizing custom membrane filtration to efficiently isolate cannabinoids, terpenes, and other bioactive compounds while reducing energy consumption. This multi-stage system begins with a custom milling machine that preprocesses biomass by separating non-target components, such as cellulose-rich stalks, to improve extraction efficiency. The core extraction process employs a series of custom membranes designed to selectively filter cannabinoids and terpenes, minimizing impurities without the need for traditional sub-zero cooling. Each membrane stage incorporates solvent recovery to recycle ethanol, reducing waste and operational costs. In the final stage, a custom concentrator removes residual ethanol, decarboxylates THCa to THC, and crystallizes sugars to prevent downstream clogging. This room-temperature extraction system significantly enhances yield, purity, and sustainability, making it a scalable and cost-effective solution for cannabis and hemp processing industries, as well as applicable for pharmaceutical and nutraceutical uses.

The invention belongs to the technical field of medicine preparation, and particularly relates to a fenoprofen calcium preparation method which comprises the following steps: 1) m-hydroxyacetophenone and bromobenzene generate an intermediate 1, namely m-phenoxyacetophenone under the action of alkali and cuprous iodide; 2) reacting the intermediate 1 with ethyl chloroacetate under the action of strong base, and then performing hydrolysis and decarboxylation reaction to generate an intermediate 2, namely 2-(3-phenoxy phenyl) propionaldehyde; the invention discloses a preparation method of fenoprofen calcium, which comprises the following steps: (1) preparing fenoprofen, (2) preparing fenoprofen, (3) carrying out oxidation reaction on an intermediate 2 to obtain fenoprofen, (4) reacting fenoprofen with a sodium hydroxide solution to obtain fenoprofen sodium, and (5) salifying fenoprofen sodium with a calcium chloride solution to obtain fenoprofen calcium.

The present invention relates to a process for the enantioselective preparation of chiral 4-substituted 2-oxazolidinones of formula (la) or (lb) via asymmetric hydrogenation of the corresponding 4-substitued 2-oxazolones of formula (II) using a combination of palladium or nickel and a chiral bidentate P-ligand as catalyst. The oxazolidinones can then be converted to important chiral building blocks such as enantiopure chiral aminoalcohols and haloamines via decarboxylative ring opening reaction.

The invention relates to the technical field of cosmetics, in particular to a compound active peptide with skin anti-aging, anti-inflammatory and soothing functions and application of the compound active peptide. The compound active peptide is prepared from acetyl hexapeptide-1, palmitoyl tripeptide-5, acetyl dipeptide-1 cetyl ester, copper peptide and decarboxylated carnosine hydrochloride. The compound peptide acts on dermal fibroblasts, so that expression of p16 and p21 genes is reduced, and cell cycle arrest is improved; the compound acts on epidermal keratinocytes and dermal fibroblasts and inhibits COX-2 gene expression; the compound peptide acts on epidermal keratinocytes and dermal fibroblasts, and the ROS level is reduced; the compound peptide acts on PC12 cells, inhibits secretion of acetylcholine, blocks transmission of neural signals, and plays a role in immediate wrinkle removal.

The invention discloses a novel acetonitrile catalyst and a preparation method thereof, and belongs to the field of chemical catalysts. The catalyst provided by the invention takes nano-scale porous carbon as a carrier and zirconium-tungsten bimetal as an active component, an acid path is synergistically inhibited through phosphorus-potassium elements, and acetone is prevented from being generated by acetic acid decarboxylation; and cerium-molybdenum is utilized to regulate and control an ammoniation path, and the directional reaction of acetic acid and NH3 is accelerated. The catalyst provided by the invention promotes the yield of acetonitrile to reach 99% or above, and the conversion rate reaches 99.99%; the generation amount of acetone is only 0.1 mol%. And the catalyst can keep high activity and selectivity for a long time, and can be revived and used for multiple times, so that the service life is prolonged.

The invention belongs to the field of pharmaceutical chemical engineering and fine chemical engineering, and relates to a method for recovering 2-cyano-2-methylvaleric acid as shown in a chemical structural formula I. The method comprises the following steps: selecting methyl 2-cyanoacetate and 1-chloropropane, and carrying out catalytic dipropylation under the action of potassium carbonate to prepare methyl 2-cyano-2-valproate; hydrolyzing the latter to obtain 2-cyano-2-valproic acid (crude product) as shown in a formula III; adding water, alcohol and other polar solvents into the 2-cyano-2-valproic acid crude product, pulping, carrying out gradient crystallization, filtering, and carrying out low-temperature vacuum drying to obtain 2-cyano-2-valproic acid monohydrate and 2-cyano-2-methylvalproic acid monohydrate; the 2-cyano-2-valproic acid monohydrate is subjected to high-temperature decarboxylation hydrolysis through sulfuric acid, and valproic acid is prepared; and carrying out high-temperature decarboxylation hydrolysis on the 2-cyano-2-methylpentanoic acid monohydrate by using sulfuric acid to obtain the essence 2-methylpentanoic acid.