23results about How to "High reaction yield" patented technology

This invention discloses a method for synthesizing cefotiam, using 7-aminocephalosporanic acid (7-ACA) as the parent nucleus and introducing a 4-dimethylaminopyridine-dimethyl carbonate composite catalytic system. The reaction is carried out in a one-pot process involving 3-position nucleophilic substitution, 7-position amidation, and simultaneous deprotection in a green mixed solvent of ionic liquid [BMIM]BF₄-water with 1-(2-dimethylaminoethyl)-1H-5-mercapto-tetrazole and compound I. This method simplifies the process, improves selectivity, produces a high-purity product with stable yield, and is suitable for industrial production.

A method for preparing a substituted acrylate compound of general formula (I) is provided.

The application discloses acetoacetamide modified polyvinyl alcohol and a preparation method thereof, and the preparation method comprises the following steps: reacting p-ester and an acetoacetamide reagent at 20-80 DEG C for 1-3h in a polar solvent to generate N-acetoacetyl p-ester; then, the N-acetoacetyl p-ester is mixed with an alkaline catalyst and polyvinyl alcohol, and is added into a double-screw reaction extruder to generate N-acetoacetyl p-ester modified polyvinyl alcohol crude product; finally, the crude product is powdered, washed with methanol for three times to remove the catalyst and reaction inorganic salt, and is filtered and dried to obtain the N-acetoacetyl p-ester modified polyvinyl alcohol. The AAE-PVA prepared by the application can be used as a protective colloid for polyvinyl acetate emulsion polymerization, has better water resistance than common polyvinyl alcohol, and the water resistance, tensile strength and stability of the prepared emulsion adhesive are obviously improved. The synthesis steps of the application are simple, the safety risk is low, and the reaction yield is high.

This invention discloses a lens-type ion mobility tube. An ion optical lens with radial divergence and then radial convergence of the ion beam is disposed within the ionization region of the ion mobility tube. This increases the probability of contact between the reactant ions generated by the ion source and neutral sample molecules, thereby enabling a sufficient ion-molecule reaction to generate high-abundance sample product ions and improving the detection sensitivity of the ion mobility tube. This ion mobility tube technology organically combines increasing the ion-molecule contact probability to improve the ion-molecule reaction yield with radial convergence of the ion beam to improve the ion number density, providing a novel approach to enhancing the detection sensitivity of ion mobility spectrometry. This technology does not require modification of the existing ion mobility tube structure; it can be achieved simply by changing the voltage applied between adjacent electrodes within the ionization region, facilitating its widespread application in the field of ion mobility spectrometry.

The application discloses a kind of photocontrol chiral ligand based on diarylethene, structural general formula is as shown in following formula:After the photocontrol chiral ligand based on diarylethene synthesized in the application and rhodium catalyst coordination, when catalyzing asymmetric carbon hydrogen amidation at room temperature, higher reaction yield and higher ee value can be obtained by using ligand in open loop state to catalyze, and lower reaction yield and lower ee value can be obtained by using ligand in light stable state to catalyze.The application makes up the deficiency that there is currently lack of photo-thermal bistable photocontrol catalyst in the field of photocontrol asymmetric catalysis, and widens the application of diarylethene in photocontrol asymmetric catalysis.

This invention relates to an industrial preparation method for 2-methylphenylacetic acid, comprising the following steps: under an inert solvent, 2-methylhalobenzene and malonate diester undergo a coupling reaction in the presence of a catalyst and base A to obtain compound one; compound one is hydrolyzed and decarboxylated under the presence of base B to prepare 2-methylphenylacetic acid; the chemical structural formula of compound one is: [formula missing], where R is a C1-C8 alkyl group. Compared with existing technologies, this invention uses inexpensive raw materials, is simple to operate, can react under normal pressure, has relatively mild conditions, is safe and environmentally friendly, and is easy to industrialize.

The present application relates to the field of organic synthesis, in particular to a kind of preparation of flubendiamide intermediate compound I method, the method includes the following steps: compound a occurs reduction in the presence of catalyst and base and obtains compound I.The present application is by adding basic compound in the process of catalytic hydrogenation reaction, effectively 2,5-dichloro-4-(1,1,2,3,3,3-hexafluorophenoxy) nitrobenzene is reduced to only obtain 2,5-dichloro-4-(1,1,2,3,3,3-hexafluorophenoxy) aniline, and the content of dechlorination by-product is low, and the product purity is high.

This invention provides a method for the catalytic hydroboration of nitrile compounds, belonging to the field of nitrile reduction technology. The method uses nitrile compounds as substrates, molybdenum hexacarbonyl as a catalyst, and pinacolborane as a hydrogen source, with the hydroboration reaction occurring at 78-82°C for 7.5-8.5 h. The reaction utilizes molybdenum hexacarbonyl as a catalyst, which is simple and readily available, requiring no complex synthesis. Furthermore, the reaction process does not require the participation of ligands. Using pinacolborane as a hydrogen source eliminates the need for strictly nitrogen-protected experimental conditions, enabling the hydroboration of nitriles. The substrate applicability is broad, applicable not only to aromatic nitriles but also to aliphatic nitriles and even some dinitriles. The reaction process does not require solvents, making it environmentally friendly. The corresponding hydroboration product is obtained directly after the reaction without further purification, and the reaction yield is high, ranging from 84-100%.

This invention relates to an electroactive porphyrin-based conjugated microporous polymer material, its preparation method, and its applications. The porphyrin-based conjugated microporous polymer is obtained from raw materials containing porphyrin-based monomers and aromatic amine monomers through a coupling reaction. The electroactive porphyrin-based conjugated microporous polymer material of this invention exhibits excellent electrochemical performance as an electrode material. Lithium-ion capacitors constructed using this material possess characteristics such as high specific capacitance, high energy density, fast charging rate, and long cycle life. This invention has good application potential in lightweight, high-specific-energy, fast-charging energy storage devices.

This invention belongs to the field of catalyst preparation and application technology, and discloses a method for preparing sulfur-bridged bimetallic alkyne complexes and their application in the dehydrogenation coupling synthesis of 1,4-diyne. The method uses thiols or thiophenol salts as bridging ligands, with each metal center coordinated with a cyclopentadienyl group or a substituted cyclopentadienyl group. This invention achieves coordination activation of the terminal alkyne by controlling the oxidation state of the metal center and altering the bonding mode of the terminal alkyne at the metal center. In this system, the sulfur-bridged ligand not only assists the metal center in activating the terminal alkyne but also stabilizes a key intermediate in the catalytic process. Subsequently, the coordinated-activated terminal alkyne undergoes a reductive elimination process to generate 1,4-diyne. This reaction can be carried out in a temperature range of -100℃ to 25℃, with a reaction time of 0.5 to 48 hours. This method can synthesize a series of novel sulfur-bridged bimetallic alkyne complexes with high yield and high selectivity, providing a novel catalytic system for the activation of C-H bonds in terminal alkynes mediated by inexpensive metals and the further synthesis of 1,4-diyne.

This invention relates to a pyridine-imine type metal complex, its preparation method, and its applications. The pyridine-imine type metal complex is an NNN-pyridine-imine type metal complex or an NN-pyridine-imine type metal complex; its structural formula is shown in Formulas 1-4. The pyridine-imine type metal complex and its preparation method described in this invention, as well as its application in hydrosilylation and silanization reactions, allow for the one-pot synthesis of the desired metal complex. The preparation method is simple and low-cost, eliminating the cumbersome separation steps in traditional two-step methods, significantly reducing reaction time, increasing the maximum yield to over 95%, and exhibiting high catalytic activity and selectivity in hydrosilylation and silanization reactions.

The application discloses a synthesis method of 2-chloro-N-[4-chloro-3-(2-pyridyl)phenyl]-4-(methylsulfonyl)benzamide, which comprises the following steps: reacting an azido trimethylsilane compound shown in formula V with an oxidant in a solvent in the presence of a catalyst and a ligand to prepare a target product, wherein the catalyst is selected from the combination of one or more of MnCl2, manganese acetylacetone Mn(acac)2, manganese acetate Mn(OAc)2, MnBr2, MnCO3, MnF2, Mn2(CO) 10 10)CoCl2 and cobalt acetylacetone Co(acac)2. The synthesis method has the advantages of short reaction route, mild reaction condition, fast reaction rate, short reaction time, high yield, high product purity, green environmental protection, and low cost.

This invention discloses a method for preparing 5,5-disubstituted-4,5-dihydroisoxazole. Specifically, the method involves the following steps: under acid catalysis, a compound of formula III undergoes a cyclization reaction with hydroxylamine and / or a hydroxylamine salt to obtain a compound of formula V. This invention provides a low-cost, economical, and environmentally friendly method for preparing 5,5-disubstituted-4,5-dihydroisoxazole, suitable for industrial-scale use.

The application provides a synthesis method of deoxycholic acid (DCA). The method takes phytosterol as a starting material, and synthesizes deoxycholic acid (DCA) through a series of steps such as primary alcohol oxidation reaction, witting reaction, hydrogenation reaction, selective reduction reaction, hydroxyl protection reaction, elimination reaction, allyl oxidation reaction and hydrolysis reaction. The synthesis method has high reaction yield and high product purity, the intermediates in each step are all solid, easy to purify, the post-treatment method is simple, the cost is low, suitable for quality control, convenient for industrialized production, and has a good application prospect. Moreover, the deoxycholic acid (DCA) synthesized by the method also avoids the risk of containing animal pathogens and other harmful factors.

This invention relates to the field of organic synthesis technology, specifically to an iodinated fatty acid ester, its preparation method, and its applications. The preparation method involves carrying out an iodination reaction of an unsaturated fatty acid ester in a mixed system of triphenylphosphine and elemental iodine. The preparation method of this invention is efficient, controllable, highly selective, and capable of generating stable iodinated fatty acid esters, thus expanding the application fields of iodinated polyunsaturated fatty acids.

This application discloses a method for synthesizing 2,6-difluorostyrene, belonging to the field of organic chemical synthesis technology, including the following steps: (1) 2,6-dichlorobenzonitrile undergoes a halogen exchange fluorination reaction with a fluorinating agent in a polar aprotic solvent to obtain 2,6-difluorobenzonitrile; (2) the obtained 2,6-difluorobenzonitrile undergoes an addition reaction with methyl magnesium halide in an inert solvent, followed by hydrolysis to obtain 2,6-difluoroacetophenone; (3) the obtained 2,6-difluoroacetophenone undergoes a carbonyl reduction reaction in a solvent to obtain 1-(2,6-difluorophenyl)ethanol; (4) the obtained 1-(2,6-difluorophenyl)ethanol undergoes a dehydration reaction in an alkane solvent under protic acid catalysis to obtain 2,6-difluorostyrene. This synthesis method has the advantages of inexpensive and readily available raw materials, good atom economy, simple reaction operation, high synthesis yield, and good product purity, making it suitable for industrial application.

The application discloses a preparation method and production process of a six-membered aromatic ring fused pyrrole compound, and belongs to the field of organic synthesis. The six-membered aromatic ring fused pyrrole compound of the target compound can be obtained in a high yield even under normal pressure by using specific low-boiling-point solvents (a mixed system of toluene and water). In addition, in the post-treatment process after the reaction is completed, a method of sequentially using sodium chloride aqueous solution washing and t-butyl methyl ether beating is used, so that the by-products can be effectively removed in the post-treatment process, and the product properties are improved.

This invention belongs to the field of catalytic synthesis technology for fine chemical products, and discloses a method for photochemical reductive coupling of aryl α-keto esters to synthesize 2,3-diaryl tartrate esters. The method includes the following steps: in an inert atmosphere, the substrate aryl α-keto ester, an electron-sacrificing reagent, a proton-sacrificing reagent, and an organic solvent are mixed, and a selective reductive coupling reaction is carried out under visible light irradiation. After the reaction, 2,3-diaryl tartrate esters are obtained by separation and purification. This invention achieves the reductive coupling of aryl α-keto esters through a hydrogen transfer strategy, avoiding the use of hazardous hydrogen gas, eliminating the formation of reduction products, providing mild reaction conditions, and achieving high reaction yields, thus showing great application potential.

The application discloses a supported nickel-based bimetallic catalyst and a preparation method and application thereof, and comprises the following steps: step one, preparing dicyanamide nickel salt and dicyanamide cobalt salt; step two, according to a certain proportion, an ionic liquid with anion of dicyanamide radical and the dicyanamide nickel salt and the dicyanamide cobalt salt prepared in the step one are weighed, and are stirred and reacted at a certain temperature, and the obtained product is dried to obtain a catalyst precursor; step three, the catalyst precursor obtained in the step two is moved into a tube furnace, is programmed to heat to a set temperature under nitrogen or inert atmosphere and is kept for a certain time, and after acid treatment, a supported nickel-based bimetallic catalyst is obtained. According to the scheme, specific raw materials are selected, and the raw material ratio and related process parameters are strictly controlled, so that the finally obtained supported nickel-based bimetallic catalyst has excellent catalytic performance, and the yield of o-chloro-p-phenylenediamine is obviously improved.

A method for the comprehensive utilization of residual C5 from cracked ethylene involves using residual C5 from cracked ethylene as a reactant, employing organic peroxides as oxidants, and conducting a catalytic oxidation reaction under the action of a catalyst to obtain a first reaction product containing 1,2-epoxypentane, 2,3-epoxypentane, 1,2-epoxy-2-methylbutane, and 2,3-epoxy-2-methylbutane. The first reaction product is then mixed with cyclopentene, and a further catalytic oxidation reaction is conducted under the action of a catalyst, causing the unreacted organic peroxides in the first reaction product to undergo an epoxidation reaction with the cyclopentene to generate cyclopentane oxide, thus obtaining a second reaction product containing 1,2-epoxypentane, 2,3-epoxypentane, 1,2-epoxy-2-methylbutane, 2,3-epoxy-2-methylbutane, and cyclopentane oxide. The catalyst is a modified Ti-HMS molecular sieve catalyst with mesoporous characteristics. Further, the 1,2-epoxypentane is hydrolyzed and separated by distillation to obtain 1,2-pentanediol. This invention provides a green and environmentally friendly method for the high-value utilization of C5 residue from cracked ethylene.

This invention discloses a preparation process for antimony glycolate with low heavy metal residues, belonging to the field of antimony glycolate production technology. The process first involves acid washing of industrial-grade antimony trioxide with dilute nitric acid and washing with high-purity water, followed by chelation resin adsorption purification of industrial-grade ethylene glycol. Subsequently, under an inert atmosphere, a stepwise feeding method is used for a controlled synthesis reaction. After the reaction, the reaction solution is pressurized at a specific high temperature and passed through a composite purification medium column composed of a specific volume ratio of thiol-based resin, molecular sieve, and diatomaceous earth for deep purification. Finally, the final product is obtained through programmed cooling crystallization, washing with mixed solvents, and vacuum drying. This invention, through a systematic purification design throughout the entire process, can reduce the content of key heavy metal impurities such as lead and arsenic in the product, significantly improving the purity of the product and its activity and stability as a polyester catalyst. Furthermore, the process exhibits good reproducibility and is suitable for industrial production.

The invention relates to a crystal form B of (S)-2-aminobutanamide hydrochloride, a preparation method of the crystal form B and a method for preparing levetiracetam by using the novel crystal form. The novel crystal form can improve the reaction yield and product purity of subsequent levetiracetam.

The application discloses a method for continuously preparing 4,4'-dichloromethyl biphenyl, which comprises the following steps: pumping a paraformaldehyde, hydrochloric acid and a catalyst solution into a first-stage tubular reactor to perform a formaldehyde depolymerization reaction, and then pumping the depolymerization reaction solution into a second-stage tubular reactor to perform a chloromethylation reaction in the presence of biphenyl and a chlorinating reagent, and finally discharging the reaction solution from the tubular reactor to perform cooling crystallization and filtration to obtain a 4,4'-dichloromethyl biphenyl crude product, and recycling and reusing the catalyst in the system. The method has the advantages of high reaction efficiency, simple system, low cost, high yield and easy industrial production.