113 results about "Ester hydrolysis" patented technology

Disclosed herein are a catalyst for polyester depolymerization or cyclic ester synthesis, a preparation method therefor and a use thereof. The catalyst is a long-chain catalyst having a main chain carbon atom number greater than or equal to 8, and containing a terminal ion group and a terminal hydroxyl structure; the catalyst may be used to catalyze polyester hydrolysis, alcoholysis or cyclic depolymerization, so as to recover corresponding monomers or monomers and oligomers, or used to catalyze hydroxy acid or hydroxy acid esters to synthesize cyclic ester monomers or cyclic ester monomers and cyclic oligomers by means of polycondensation and cyclization reactions. The catalyst may reduce the viscosity of a reaction system, and may greatly improve the utilization rate of a catalytic active center, reduce the consumption of the catalyst and improve overall catalytic efficiency, achieving high-efficiency, high-yield and selective depolymerization of polyester homopolymers, copolymers, blends or compounds.

The present disclosure provides PEG lipids and transfer vehicle compositions including the same. Incorporation of the PEG lipids of this disclosure into a transfer vehicle can provide for one or more desirable properties, including low immune response and / or immunogenicity, fast-shedding of the PEG lipid from the transfer vehicle, and / or degradability of the PEG lipid, e.g., via ester hydrolysis or cleavage.

The invention relates to the technical field of nanofiber membrane materials, in particular to a heat-insulation and warm-keeping nanofiber membrane material and a preparation method thereof.A mixed solution of tetraethoxysilane hydrolysate and a polyvinyl alcohol aqueous solution serves as a precursor of electrostatic spinning, modified titanium dioxide hollow microspheres are added in the preparation process, and the nanofiber membrane material is prepared; a near-vacuum environment is formed in the titanium dioxide hollow microspheres, heat is conducted by inhibiting collision of gas molecules, so that radiation heat transfer is blocked, the prepared nanofiber membrane material has a good heat preservation and heat insulation effect, a silane coupling agent forms hybrid bonds on the surfaces of the microspheres and is combined with polyvinyl alcohol molecular chains through chemical bonds, and the heat preservation and heat insulation effects are improved. The interface adhesion force is obviously improved, so that the hollow microspheres are prevented from collapsing during mechanical friction or bending; secondly, different types of quaternary ammonium salt antibacterial agents are compounded, the synergistic sterilization effect can be achieved, four quaternary ammonium salts are synergistic through different action targets, and the problem that a single antibacterial agent is prone to generating drug resistance can be solved.

The invention discloses a FeNi soft magnetic composite material based on tetrabutyl orthosilicate hydrolysis coating and a preparation method of the FeNi soft magnetic composite material. According to the method, through a controllable sol-gel process, tetrabutyl orthosilicate is hydrolyzed to generate SiO2 gel, then a uniform and ultrathin SiO2 gel layer is generated on the surface of FeNi powder in situ, and then heat treatment densification is performed to obtain the FeNi soft magnetic composite material coated with SiO2 in an insulation mode. The SiO2 insulating layer is firmly combined with the matrix metal powder, the thermal stability is good, high frequency and high resistivity are achieved, and meanwhile dilution of non-magnetic relative magnetic performance is reduced to a great extent. The final magnetic core is obtained through compression molding and annealing heat treatment, has the excellent characteristics of high effective magnetic conductivity and low high-frequency magnetic core loss, and is particularly suitable for various efficient and miniaturized power electronic devices in the MHz frequency band.

The invention discloses a preparation method of an arfamarana key intermediate, which comprises the following steps: carrying out nucleophilic addition reaction on a compound I and 1-[3-chloro-5-(trifluoromethyl) phenyl]-2, 2, 2-trifluoroethanone under the action of an organic solvent A and alkali to obtain a compound II; dissolving the compound II in an organic solvent B, adding concentrated sulfuric acid, carrying out intramolecular dehydration and cyanogen hydrolysis, and after the reaction is finished, cooling to room temperature for crystal growing to obtain a compound III; dissolving the compound III in an organic solvent C, carrying out intramolecular cyclization and ester hydrolysis reaction on the compound III and hydroxylamine hydrochloride under the action of a certain amount of sodium hydroxide aqueous solution, and after the reaction is finished, collecting a water phase and adjusting the pH value of the water phase, so as to obtain the key intermediate of arfampanaga. The reaction in each step has a high conversion rate, the purity of the prepared arfamarin intermediate is high, and powerful support and guarantee are provided for preparation of high-purity arfamarin.

The invention relates to a preparation method of a Pd-based catalyst and application of the Pd-based catalyst in catalytic synthesis of biphenyltetracarboxylic dianhydride. According to the method, an alkaline substance is added, and nickel oxide is modified and regulated through hydroxyl, so that the specific surface area of the Pd / NiO catalyst is increased, and the effect between Pd and NiO is enhanced; the obtained catalyst can promote coupling of halogenated phthalic anhydride, and the synthesis efficiency of biphenyl tetracarboxylic dianhydride is improved. The catalyst is simple in preparation process and excellent in performance and is applied to synthesis of biphenyltetracarboxylic dianhydride, and esterification and ester hydrolysis steps do not need to be added.

The utility model relates to the technical field of chemical production equipment, and discloses an ester hydrolysis reactor, which is characterized in that a gas channel and a liquid channel are arranged in a spray head, gas is conveyed into a tank body through the gas channel, and liquid is injected into the tank body through the liquid channel. In the process, the gas and the liquid can be injected into the tank body through the spray head at the same time. Meanwhile, the gas and the liquid are immediately mixed after being sprayed out from the spray head, and hydrolysis is carried out to generate corresponding acid and alcohol. And secondly, in the downward scattering process of the gas and the liquid sprayed by the spray head, the gas and the liquid are further mixed. In addition, the liquid is sputtered when being scattered to the bottom of the tank body, and the sputtered liquid is mixed with surrounding gas again. Therefore, the mixing efficiency can be improved, and the hydrolysis reaction of gas and liquid is more sufficient.

The application discloses a preparation method of a titanium dioxide coated MIL-53(Fe) electrocatalyst. First, a catalyst MIL-53(Fe) is obtained through a hydrothermal method, then the catalyst is heated, stirred and dried under mild conditions, and titanium dioxide obtained by hydrolysis of tetra-n-butyl titanate is uniformly coated on the MIL-53(Fe) under the action of dodecyl sulfate, finally, the catalyst is improved in contact with nitrogen through heat treatment, so that the titanium dioxide coated MIL-53(Fe) with good stability is prepared.

The application discloses a Pseudomonas atacamensis STR8 and an application thereof, and belongs to the technical field of microorganisms. The strain is classified and named as Pseudomonas atacamensis STR8, and the preservation number is CCTCC NO: M 2025609. The hydrolysis circle HC value of the strain on a tributyrin plate is 2.78, and the lipase activity reaches 139.86 U / mL. The application also provides an application of the strain and a lipase produced by the strain in catalyzing hydrolysis of tocopherol succinate to prepare tocopherol. The strain STR8 is fermented to obtain a crude enzyme liquid, and the crude enzyme liquid is added into a reaction system containing the tocopherol succinate to perform a hydrolysis reaction. After 9 hours of reaction, the content of the tocopherol is increased by 750% compared with a control group. The strain and the method provided by the application have high catalytic efficiency, mild reaction conditions and environmental friendliness, and are suitable for green industrialized production of the tocopherol.

The invention belongs to the technical field of electrolysis, and discloses a method for preparing p-hydroxyanisole through electrolytic oxidation of anisole. The method comprises the following steps: S1, adding anisole, an acylation reagent, an organic alkali proton trapping agent and an alkaline amine group-containing solvent into a single-chamber electrolytic bath together, starting electrification, carrying out electrolysis, and obtaining a product liquid containing p-methoxytrifluoroacetic acid phenyl ester in the single-chamber electrolytic bath after electrolysis is finished; the organic base proton trapping agent is at least one of N, N-diisopropylethylamine, tributylamine and tripropylamine; and S2, adding a saturated sodium bicarbonate aqueous solution into the product liquid containing p-methoxytrifluoroacetic acid phenyl ester in the step S1 to hydrolyze p-methoxytrifluoroacetic acid phenyl ester, and extracting to obtain p-hydroxyanisole. The selectivity of para-position and ortho-position products of methoxyl on anisole is regulated and controlled, so that the selectivity of p-hydroxyanisole prepared by the method is higher.

This invention belongs to the field of chemical pharmaceutical technology, and particularly relates to a method for preparing an anti-puncture flash evaporation material. Addressing the issue that the hydrophilicity of the molecular structure in existing technologies needs improvement, this invention provides a maleic methylamine polyethylene glycol activated ester and its preparation method, comprising a reaction condensation of 3-maleimide propionic acid and tert-butyl methylamine polyethylene glycol propionate, followed by acid hydrolysis of the ester, and then adding the activated ester for a catalytic reaction to obtain the final product Mal-CH2CH2COO-N(CH3)-(PEG). n -CH2CH2COONHS. This invention creatively designs a maleic methylamine polyethylene glycol activated lipid structure. The methylamine structure can increase solubility in aqueous media, making it more hydrophilic than the existing Mal-CH2CH2COO-PEG-COONHS molecular structure, which is more conducive to the binding of drugs to the human body environment.

The invention provides a preparation method of polypeptide, which comprises the following steps: dissolving a compound as shown in a formula I, a compound as shown in a formula II, pivaloic anhydride, an alkaline substance and N-methylimidazole in an organic solvent to obtain a reaction mixed solution, reacting at 15-80 DEG C for 3-10 hours, performing post-treatment on the obtained reaction solution to obtain a dipeptide compound as shown in a formula III, and performing ester hydrolysis on the dipeptide compound as shown in the formula III to obtain the polypeptide. The preparation method comprises the following steps: dissolving a compound as shown in a formula I in an organic solvent to obtain a dipeptide compound only containing an Fmoc protecting group, dissolving the dipeptide compound only containing the Fmoc protecting group, a compound as shown in a formula II, pivaloic anhydride, an alkaline substance and N-methylimidazole in the organic solvent, reacting at 15-80 DEG C for 4-10 hours, and post-treating the obtained mixed solution to obtain the polypeptide. According to the invention, pivaloic anhydride is used as a condensing agent, the structure is simple, the reaction is safe, cheap and non-toxic, only a catalytic amount of N-methylimidazole is needed in the reaction, a large amount of nitrogen-containing by-products are not generated, and purification is easy; various amino acid side chains can be tolerated, and racemization isomerization cannot occur in the reaction; environment-friendly solvents such as ethyl acetate are used, and the reaction conditions are mild.

The present invention generally pertains to methods of quantifying free fatty acids in a pharmaceutical formulation. In particular, the present invention pertains to a method of quantifying free fatty acids released from polysorbate hydrolysis in a pharmaceutical formulation comprising a pharmaceutical product, polysorbate and free fatty acids, using liquid chromatography-mass spectrometry, without the use of an extraction step.

Methods for preparing an L-6-hydroxytryptophan (HTP) derivative and intermediates thereof are provided. The methods for preparing the various intermediates of the L-6-HTP derivative are provided, on the basis of which the L-6-HTP derivative could be obtained. Specifically, the L-6-HTP derivative is obtained by using a compound A6-0 with a structure shown in Formula 1 as a starting reaction raw material, and subjecting the compound A6-0 to triisopropylsilyl (TIPS) protection, coupling, carbon-boron bond oxidation, hydroxyl-targeted benzyl protection, TIPS protective group removal, tert-butoxycarbonyl (Boc) protective group removal, methyl ester hydrolysis, and amino-targeted 9-fluorenylmethoxycarbonyl (Fmoc) protection in sequence.

The application relates to a preparation method and application of an azobenzene-based pH / UV intelligent response information reversible load hydrogel robot, and belongs to the technical field of hydrogels. The application aims to solve the problem that a light response information load material cannot be rewritable, high-strength, fast in response speed and multifunctional. The azobenzene-based pH / UV intelligent response information reversible load hydrogel robot is prepared by the following steps: synthesizing 4-hydroxy azobenzene by a diazo method; taking 4-hydroxy azobenzene, potassium carbonate, 6-bromohexyl acetate and acrylamide as raw materials; adopting Williamson ether reaction, nucleophilic substitution reaction, ester hydrolysis and amide reaction to prepare azobenzene-based gel monomers; taking acrylamide and the azobenzene-based gel monomers as a gel matrix; taking N,N'-methylene bisacrylamide as a crosslinking agent; and adopting free radical polymerization, hydrogen bond crosslinking and hydrophobic crystallization crosslinking strategies to prepare the azobenzene-based pH / UV intelligent response information reversible load hydrogel robot, which is applied to intelligent information load and rewritable code transmission.

The present invention proposes a polyester fiber super-hydrophilic fabric and a preparation method thereof, which belongs to the technical field of super-hydrophilic textiles, and is used to solve the technical problems of poor rapid tiling and rapid transmission effect of liquid water in polyester fabrics. Specifically, it includes five steps: blending, weaving, finishing, washing and baking. Polyester fiber and wool fiber are blended to prepare polyester / wool blended yarn with a certain mixing ratio, and polyester / wool blended fabric is prepared by weaving. The yarn is placed in a finishing liquid containing a certain amount of reducing agent with a pH value between 12-14 for treatment. The wool is hydrolyzed to form free amino acids and react with the products of polyester ester hydrolysis, thereby constructing a rough hydrophilic interface on the surface of the polyester fiber. After washing and baking, the polyester fiber super-hydrophilic fabric is obtained. The present invention provides a method for preparing a polyester fiber super-hydrophilic fabric. The prepared polyester fiber super-hydrophilic fabric has super-hydrophilicity, simple process, strong operability, and high market application value.

The invention discloses a preparation method of lithium difluoro (oxalato) borate. Lithium hydroxide, trimethyl borate, dimethyl oxalate and anhydrous ammonium bifluoride steam are used as raw materials to react in an ionic liquid medium. The method adopts a plasma activation technology, can be efficiently carried out in a low-temperature environment without traditional heating, not only shortens the reaction period, but also can inhibit fluorine source decomposition, oxalate hydrolysis and other side reactions, improves the selectivity of a target product, and uses the ionic liquid as a reaction medium, and the high polarity and low volatility of the ionic liquid can ensure the uniform dispersion of raw materials. Meanwhile, supercritical carbon dioxide extraction replaces traditional recrystallization, one-step purification is achieved by means of the selective dissolution characteristic of supercritical carbon dioxide extraction, the process steps are simplified, and solvent residues are reduced.

This invention relates to a method for preparing trinitromethyl tricyclic compounds containing nitrogen-rich groups, belonging to the field of energetic materials technology. The specific preparation steps are as follows: Scheme 1 uses 2,3-diaminomaleonitrile to obtain the corresponding methyl ester-substituted intermediate through multiple steps of cyclization, acidification, and esterification. Then, through multiple steps of hydrazine substitution, cyclization with ethyl 3-ethoxy-3-iminopropionate hydrochloride, ester hydrolysis, and nitration, the target compound trinitromethyl tricyclic compound 2 is successfully synthesized. Scheme 2 uses ethyl diazonium acetate to obtain the corresponding methyl ester-substituted intermediate through multiple steps of cyclization, acidification, and esterification. Then, through multiple steps of hydrazine substitution, cyclization with ethyl 3-ethoxy-3-iminopropionate hydrochloride, nitration, salt formation, and renitration, the target compounds trinitromethyl tricyclic compounds 1, 3, and 4 are synthesized. The target compound has advantages such as high nitrogen content, high density, good thermal stability and excellent detonation performance, and can be used as a component of energetic materials, showing potential application value.

This invention relates to the field of molecular sieves, specifically to titanium-silicon molecular sieve TS-1 nanosheets, their preparation method, and applications. The invention uses tetrapropylammonium hydroxide, tetraethyl orthosilicate, tetrabutyl titanate, and urea as raw materials. The process involves crystallization followed by calcination to prepare titanium-silicon molecular sieve TS-1 nanosheets. This invention employs a urea-assisted synthesis method, where urea spontaneously disperses on the surface of the crystals perpendicular to the b-axis, inhibiting crystal growth along the b-axis direction. This results in the formation of sheet-like titanium-silicon molecular sieve TS-1 after calcination. This invention eliminates the need for isopropanol as a solvent and the regulation of hydrolysis of tetraethyl orthosilicate and tetrabutyl titanate, achieving low-cost synthesis of titanium-silicon molecular sieve TS-1 nanosheets and overcoming the technical defects of existing technologies where calcination leads to structural collapse.

The invention relates to a synthesis method of an etogliflozin impurity (a compound as shown in a formula I). The method comprises the following steps: by taking a compound in a formula II as a starting raw material, firstly carrying out oxidation reaction to prepare carboxylic acid, and then carrying out hydrogenation debenzylation and ester hydrolysis to obtain a compound in a formula I, according to the present invention, with the method, the etogliflozin impurity can be efficiently and simply synthesized, and the etogliflozin bulk drug and the etogliflozin preparation can be conveniently subjected to quality research and analysis so as to ensure the safety of etogliflozin production and medication.

The application provides a kind of imaging photothermal gold shell coated long afterglow nanomaterial and its preparation and application.The nanomaterial includes Cr doped zinc-gallium-germanium oxide long afterglow nanometer core, mesoporous silica shell layer coated on the surface of the nanometer core and gold shell layer coated on the outer surface of the mesoporous silica shell layer.The preparation method includes: hydrothermal reaction and calcination to prepare long afterglow nanometer core;Under the condition of alkali, make tetraethyl orthosilicate (TEOS) hydrolysis and condensation to form mesoporous silica shell layer, remove template and carry out amination under cetyltrimethylammonium bromide (CTAB) template;Gold ions are adsorbed on the aminated surface and reduced to form gold seeds using borohydride, and gold shell layer is formed by promoting growth using hydroxylamine salt in a gold precursor solution containing carbonate.The obtained nanomaterial has near-infrared long afterglow luminescence capability, and generates photothermal heating under 808 nm laser irradiation, which can be used for bacterial imaging and photothermal treatment of bacterial samples.

This invention provides a method for preparing pyrrolidine derivatives, belonging to the field of organic synthesis. The method comprises the following steps: Step 1, reacting compound 1 in the presence of an alkaline ester hydrolysis reagent to obtain compound 2; Step 2, adding compound 2 to an aqueous solution of hydrogen bromide, followed by the addition of sodium nitrite to react and obtain compound 3; Step 3, reacting compound 3 in the presence of a dehalogenating reducing agent to obtain compound 4; Step 4, reacting compound 4 in the presence of a carbonyl reducing agent to obtain compound 5. The preparation method provided by this invention enables the industrial production of compound 5 and its derivatives.

The application discloses a preparation method of 2-acetylamino-4-[(2-hydroxyethyl)sulfonyl]benzoic acid. The 2-acetylamino-4-[(2-hydroxyethyl)sulfonyl]benzoic acid is prepared from 4-fluoro-2-nitrobenzoic acid methyl ester as a starting material through aromatic nucleophilic substitution reaction, nitro reduction reaction, ester hydrolysis reaction, amino acylation reaction, thioether oxidation reaction and the like. The method has the advantages of mild reaction condition, high yield, low cost, easy availability of raw materials, and the like. The synthesis process meets the requirements of green chemistry, the synthesis route is innovative, the reaction post-treatment is simple, and the product is easy to purify.

The invention provides a one-pot preparation method of a bepedioic acid intermediate, which comprises the following steps: S1, taking DMSO (dimethylsulfoxide) as a reaction solvent, adding 7-bromo-2, 2-dimethyl ethyl heptanoate and p-methylbenzenesulfonyl methyl isocyanide, and carrying out addition reaction under the catalysis of alkali; s2, water is added for quenching excessive alkali, and then an organic solvent is added for extraction; s3, dropwise adding concentrated hydrochloric acid to carry out an acid hydrolysis reaction; s4, washing; s5, carrying out vacuum concentration on the organic phase, and carrying out ester hydrolysis reaction by taking an alkali metal compound as a catalyst; s6, adding water and dichloromethane for extraction, collecting a water layer, dropwise adding concentrated hydrochloric acid, crystallizing, filtering and drying to obtain a product. The target product is directly obtained through condensation, acid hydrolysis, ester hydrolysis and other basic chemical reactions through a one-pot method, the process is simple, operation is convenient, the reaction efficiency is improved, and the usage amount of solvents and reagents is reduced; and the method is energy-saving and environment-friendly, can further reduce environmental pollution, and has a good industrial application prospect.

The application relates to a chiral triazole-oxazoline compound and a preparation method and application thereof, and belongs to the technical field of organic synthesis. The chiral triazole-oxazoline compound has the structural formula: the preparation method comprises the steps of click reaction, triazole N2 substitution reaction, Suzuki coupling, triazole ester hydrolysis, amidation with a chiral amine alcohol and dehydration condensation. After a chiral triazole-oxazoline compound and a palladium salt compound are added to generate a catalyst in situ, asymmetric addition of aryl boronic acid on a carbon-carbon double bond of a prochiral organic compound is carried out to prepare a chiral organic compound. The application has the advantages of low raw material cost, few synthesis steps, low experiment site requirement, relatively mild reaction conditions and simple operation for preparing the novel triazole-oxazoline compound.

The present invention belongs to the technical field of fluorescent probes, and specifically relates to a formaldehyde fluorescent probe based on formaldehyde-induced catalytic hydrolysis of aminocarboxylic acid hydroxylamine esters, a preparation method thereof, and applications thereof. The preparation of the formaldehyde fluorescent probe specifically comprises the following steps: S1: a naphthalimide derivative A is refluxed with triphosgene and 4-dimethylaminopyridine in a toluene solution to obtain an intermediate B; S2: the intermediate B is reacted with a hydroxylamine derivative C in a dichloromethane solution at room temperature to obtain a probe compound I; the molar ratio of the naphthalimide derivative A, triphosgene, and 4-dimethylaminopyridine in S1 is 1:1.5:3; the molar ratio of the intermediate B to the hydroxylamine derivative C in S2 is 1:1.3; the fluorescent probe of the present invention can selectively and rapidly react with formaldehyde to generate a product with strong fluorescence, and exhibits high selectivity and sensitivity to formaldehyde.

The invention provides a synthesis method of an etogliflozin impurity (a compound as shown in a formula III). The method comprises the following steps: by taking etogliflozin as an initial raw material, firstly carrying out acetylation reaction to prepare a peracetylated intermediate (a compound in a formula I), then carrying out selective deethylation reaction to obtain a compound in a formula II, and finally carrying out ester hydrolysis reaction to remove an acetyl protecting group to obtain a compound in a formula III. According to the present invention, the Eutogliflozin impurity can be efficiently and simply synthesized, and the quality research and analysis can be conveniently performed on the Eutogliflozin bulk drug and the Eutogliflozin preparation so as to ensure the safety of Eutogliflozin production and medication.

A method for synthesis of Lorazepam in a continuous flow using continuous flow reactor, in which method comprises five steps including N-acylation, diazepine ring closure, imine N-oxidation, Polonovski-type rearrangement, and ester hydrolysis; a green reagent comprising a peroxide reagent and rhenium oxide catalyst for N-oxidation of delorazepam; and an ammonium source combination for the synthesis of delorazepam.

This invention discloses a method for preparing lentilana-degraded impurities. Starting with 3-methyl-5-[5-(3,4,5-trichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazol-3-yl]-thiophene-2-carboxylic acid and glycine ester, a condensation reaction is carried out under a condensing agent catalysis, followed by ester hydrolysis under alkaline conditions to obtain lentilana-degraded impurities. This invention features a concise synthetic route, mild reaction conditions, simple operation, and a purity exceeding 96.0%, avoiding the problem of low purification efficiency associated with chromatographic column separation.

This document discloses methods for generating peptides, including liquid-phase peptide synthesis methods in which peptide elongation is carried out in one-pot cycles of one or more. Specifically, this disclosure provides liquid-phase peptide synthesis methods using a solvent system comprising 2-methyltetrahydrofuran for condensation reactions, and aggregation liquid-phase peptide assembly methods in which benzyl alcohol anchor groups are selectively removed from N-protected C-protected peptides via base-catalyzed ester hydrolysis.