28 results about "Reductive amination" patented technology

This application relates to a terphenylamine skeleton compound, its preparation method, and its application, belonging to the field of chemical synthesis technology. The preparation method of the terphenylamine skeleton compound of this application includes the following steps: dissolving 2,4,6-triphenylaniline with thiazole-4-carboxaldehyde or thiophene-3-carboxaldehyde in a solvent, conducting a reductive amination reaction under reducing agent conditions, quenching, extraction, washing, concentration to remove solvent, and purification to obtain the terphenylamine skeleton compound. This application provides a simple and mild synthetic method for the natural active products 5'-phenyl-N-(thiazol-4-ylmethyl)-[1,1':3',1''-terphenyl]-2'-amine and 5'-phenyl-N-(thiophene-3-ylmethyl)-[1,1':3',1''-terphenyl]-2'-amine, which can only be extracted from the secondary metabolites of the marine fungus Aspergillus sp. Furthermore, this method utilizes widely available raw materials, which is beneficial for large-scale industrial production of these natural active products.

Mutants M203A and M203A / S241L of the reductive amination enzyme IR-G36-M5 are provided, as well as the use of said mutants in the catalytic asymmetric reductive amination synthesis of (R)-N-Boc-3-cyclopropylpiperidine or (R)-N-Boc-3-cyclopropylazheptanane.

This invention discloses a compound of formula I and a method for preparing minocycline hydrochloride. The method for preparing compound I involves dissolving 6-demethyltetracycline in acidic water, adding a chlorination reagent for chlorination, then adding p-aminobenzenesulfonic acid diazonium hydrochloride and alkaline solution for coupling reaction, followed by post-treatment. The method for preparing minocycline hydrochloride uses 6-demethyltetracycline as a starting material, proceeding through the intermediate of compound I, and removing the C7 chlorine, p-aminobenzenesulfonic acid group, and C6 hydroxyl group via catalytic hydrogenation, followed by reductive amination and post-treatment. This invention achieves low-pressure palladium-carbon catalytic removal of the C6 hydroxyl group by introducing an electron-donating amino group at the C7 position, eliminating the need for expensive rhodium-carbon catalysts. The reaction conditions are mild, column chromatography purification is unnecessary, the overall yield is ≥85%, and the product purity is ≥96%, making it suitable for industrial production.

This invention relates to a high-efficiency outdoor flame retardant additive, its preparation method, and its application, belonging to the field of polymer material additives technology. This high-efficiency flame retardant additive has N,N'-di(3-aminopropyl)-1,2-ethylenediamine as its main chain, linked with dialkoxy-monochlorotriazine, containing six N-cyclohexyloxy hindered amine groups, with a purity ≥99.5% and a total yield ≥80%. It is prepared from 2,2,6,6-tetramethylpiperidone nitroxide radical, cyclohexane, etc., via N-cyclohexyloxylation, reductive amination, N-acylation, and nucleophilic substitution reactions. Adding 0.5~3.0 wt% of this stabilizer to polypropylene materials can impart UL-94 VTM-0 flame retardancy and excellent photothermal stability. Furthermore, the preparation process is low-cost and environmentally friendly, solving the technical problems of easy deactivation of hindered amines, functional separation of additives, and low yield in traditional synthesis processes. It is suitable for polypropylene fibers, films, nonwoven fabrics, and other polyolefin products.

The present application relates to Cu-based multimetallic catalyst and preparation method and application in the preparation of binary amine by the amination of binary acid / dimethyl ester compound; the catalyst is Cu 0 -Cu⁺‑M X , M is one or more metal elements selected from one or more of Zn, Al, Cu 0 Coexist with Cu⁺ in the form of bivalent state; the catalyst preparation method is simple, the raw material is cheap, and the catalyst can be reused, and after 5 cycles, the catalytic performance remains stable, and the conversion rate and yield decrease less than 5%; it is suitable for one-pot reduction amination reaction of binary acid and dimethyl ester, and high-efficiency conversion is realized under mild conditions, and the product yield and selectivity are significantly higher than those of traditional single-metal catalyst. The product is directly subjected to GC-MS and FID qualitative and quantitative analysis; the product yield is high, the yield of nonanediamine and decanediamine reaches 99.9%, and the problem of difficult reaction selectivity control, many side reactions and complex product distribution in the prior art is solved.

The application relates to the technical field of synthesis, and particularly discloses a preparation method of a levocetirizine hydrochloride intermediate. The method comprises the following steps: 4-chlorobenzophenone and anhydrous piperazine are subjected to a reductive amination reaction in an organic solvent containing a catalyst to obtain 1-[(4-chlorophenyl)benzyl]piperazine; the 1-[(4-chlorophenyl)benzyl]piperazine is subjected to resolution in an organic solvent by using L-di-p-methylbenzoyl tartaric acid as a resolution agent, and then is subjected to isolation under alkaline conditions to obtain a levocetirizine hydrochloride intermediate (R)-1-[(4-chlorophenyl)benzyl]piperazine. The raw materials and auxiliary materials used in the application are easy to obtain, a novel, efficient and green process route is developed, the whole reaction route is short and simple to operate, the obtained levocetirizine hydrochloride intermediate (R)-1-[(4-chlorophenyl)benzyl]piperazine has high yield, the total yield reaches up to 40% calculated from 4-chlorobenzophenone, and the industrialized production can be realized.

The application discloses a preparation method of a dispersant for ceramics and belongs to the technical field of ceramic dispersants. The method uses 4-carboxyl-4'-bromoterphenyl, 4-formylphenylboronic acid, dopamine and amino-terminated polyethylene glycol monomethyl ether as raw materials, and the target dispersant is prepared through three-step reactions of Suzuki coupling, reductive amination and amidation. The prepared dispersant has an accurate structure of "dopamine double-site anchoring-terphenyl rigid skeleton-pure polyether hydrophilic end", is firmly anchored on the ceramic surface through synergistic adsorption of coordination bonds and double hydrogen bonds, and realizes spontaneous vertical orientation adsorption of molecules by relying on the solvation pulling force of the polyether chain and the leverage effect of the rigid skeleton. The dispersant can significantly reduce the viscosity of ceramic slurry, improve the storage stability and green strength, and has low high-temperature residual ash content, and is suitable for various ceramic systems. The synthesis process is simple and easy for industrial production.

This invention discloses a method for surface-modified biomaterials and a modified pericardial material, relating to the field of biomedical materials technology. The method includes the following steps: S1, providing animal pericardial material cross-linked with glutaraldehyde; providing a bridging molecule containing a first bridging group and a second bridging group, and a phosphorylcholine polymer with a third bridging group at its end; binding the first bridging group to an aldehyde group on the surface of the pericardial material via a first covalent reaction; binding the second bridging group to the third bridging group via a second covalent reaction, thereby achieving grafting of the phosphorylcholine polymer onto the material surface; the first covalent reaction and / or the second covalent reaction include Schiff base formation and reductive amination processes. The modified pericardial material prepared in this application introduces a phosphorylcholine biomimetic coating, which can improve blood compatibility on the material surface, reduce activation of the coagulation system and platelet adhesion, and inhibit the initiation of calcium ion deposition on the material surface, while exhibiting high safety.

Process for continuously preparing N-methyl-diethanolamine (MDEOA), the process comprising: a) feeding diethanolamine (DEOA), a methanolic formaldehyde solution and hydrogen into a reactor equipped with a heterogenous hydrogenation catalyst; and b) subjecting DEOA, hydrogen and formaldehyde to a reductive amination in the presence of the heterogenous hydrogenation catalyst to obtain MDEOA; and c) withdrawing from the reactor a reactor effluent comprising the MDEOA.

This invention belongs to the field of medicinal chemistry, specifically relating to a method for synthesizing ivcarboxylate. The specific technical solution includes: a method for synthesizing ivcarboxylate, comprising: reductive amination of a chiral amine with a benzyl-protected nitrogen atom with a pyrrolidone, followed by catalytic hydrogenation to remove the protecting group, thereby obtaining ivcarboxylate. The preparation method provided by this invention has a short synthetic route, relatively mild preparation conditions, and great application potential.

The application discloses a method for preparing phenylethylamine by reducing and aminating acetophenone and a catalyst used in the method. The catalyst is prepared by a preparation method comprising the following steps: 1) loading active metal oxide on a support to obtain an active metal oxide / support; 2) synthesizing a molecular sieve carrier in the presence of the active metal oxide / support to obtain a catalyst precursor; 3) treating the catalyst precursor with an acid solution to obtain an acid-modified catalyst precursor; and 4) calcining and reducing the acid-modified catalyst precursor to obtain the catalyst. The acid is selected from citric acid and / or naphthalene carboxylic acid; and the molar concentration of the acid solution is 0.05-0.2 mol / L. The catalyst is used to accurately control the adsorption mode of acetophenone, the reaction selectivity is improved, the target product is easy to separate, and the purity of the target product is very high after purification.

The application is suitable for the technical field of drug synthesis, and provides a continuous flow preparation method and system of a secondary amine derivative of C9 position of omadacycline, the method is that minocycline C9-amino methylate, alkyl aldehyde compound and tertiary amine acid acceptor are dissolved in an organic solvent to form a raw material liquid, hydrogen is continuously introduced into a microreactor filled with a solid palladium carbon catalyst, and a reductive amination reaction is carried out under the condition of 50-70 DEG C and 1.0-2.5 MPa, the residence time of the material is 10-30 minutes, and high-purity product is obtained after post-treatment. The special system includes a feeding module, a mixing and preheating module, a microreaction module, a detection and control module and a product collection module, and each module cooperates to realize continuous and high-precision reaction. The application solves the defects of low efficiency, high safety risk and unstable product quality of the traditional kettle process, the product yield is more than 95%, the HPLC purity is higher than 98.5%, and the application is intrinsically safe, easy to industrialize, and environmentally friendly.

The application discloses a method for preparing cyclohexylamine by catalytic reduction and amination of phenol, which takes lignin-derived phenol as raw material, takes ammonia as ammonia source, takes water as solvent, and is prepared by reaction in a hydrogen atmosphere under the action of a supported bimetallic multifunctional catalyst. The catalyst takes SAPO-5 as a carrier, and effective active ingredients include oxides of ruthenium and manganese. The method for preparing cyclohexylamine is green and environmentally friendly, has low production cost, high product yield, high catalyst activity and recycling, and has obvious industrial production advantages.

This invention discloses a continuous preparation method and application of a core-shell Cu-based catalyst. The method utilizes membrane dispersion microreactor technology, precisely controlling the solution pH and total flow rate to uniformly coat the metal core with SiO2 at a moderate condensation rate, forming a core-shell structure with uniform particle size and regular morphology. This structure provides abundant active sites and enhances the catalyst's hydrogenation activity. Simultaneously, the mutual doping of Cu and Ni creates a synergistic effect; the introduction of Ni significantly improves the catalyst's ability to dissociate H2 to generate activated hydrogen, promoting the adsorption and activation hydrogenation of the imine intermediate. The catalyst prepared by this invention exhibits excellent catalytic activity and stability in the reductive amination of 2,2,6,6-tetramethyl-4-piperidinone and n-butylamine to N-butyl-2,2,6,6-tetramethyl-4-piperidinamine.

This invention discloses a mutant of PjTA-R6 transaminase, its construction method, and its applications. Using schizosphingine, a key precursor of large-volume monoterpene indole alkaloids, as the target for reductive amination, this invention rationally designs the PjTA-R6 transaminase through a global free energy optimization strategy, obtaining 10 mutants with significantly higher catalytic efficiencies than the original PjTA-R6 transaminase. Recombinant *E. coli* strains based on these mutants are then constructed, resulting in a substantial improvement in reductive amination catalytic efficiency. The PjTA-R6 L164E / L57F mutant provided by this invention achieves a 99% conversion rate of schizosphingine to bacamargine via whole-cell reductive amination, a 46% increase compared to the original strain. The PjTA-R6 transaminase mutant provided by this invention exhibits significant catalytic efficiency, offering a powerful tool enzyme for overcoming the industrial bottleneck of transaminase catalysis of large-volume substrates, and possesses broad application prospects.

The application relates to the technical field of chiral organic compound synthesis, and particularly discloses a preparation method of (R)-1-(tetrahydrofuran-2-yl)ethylamine. The method uses cheap and readily available (R)-tetrahydrofuran-2-carboxylic acid as a starting material, and sequentially carries out methyl esterification, nucleophilic substitution, Grignard methylation, reductive amination, and salt precipitation-alkali dissociation purification steps under the catalysis of a tertiary amine sulfonic acid inner salt type polymeric ionic liquid resin, so as to obtain a target product with high optical purity. The application introduces a polymeric ionic liquid resin catalyst with a specific structure, inhibits racemization of an alpha-chiral center in an esterification process from the source, ensures complete retention of chiral configurations in each process step, fundamentally solves the problem of optical purity reduction caused by a traditional concentrated sulfuric acid catalysis process, can stably maintain the ee value of the target product at more than 99%, the product has high optical purity, and the method is easy to realize large-scale industrial production, so the method has remarkable industrial application value and economic benefits.

This invention provides a method for preparing benzoxazine film-forming resin precursor materials and their applications, belonging to the fields of organic synthesis and semiconductor photoresist technology. The method uses substituted o-aminophenol as a starting material and proceeds through four steps: nucleophilic substitution cyclization, regioselective bromination, amide-selective reduction, and reductive amination, to prepare N-substituted brominated dihydrobenzoxazine compounds. This invention achieves specificity of the sequential reaction sites through differences in reactivity and control of process parameters, resulting in products with high purity and ultra-low or even no metal ion residue. The N-substituted brominated dihydrobenzoxazine compounds prepared by this invention have low curing temperatures, high crosslinking activity, and possess both bromine atom active sites and a rigid benzoxazine framework, making them suitable as precursor materials for film-forming resins in photoresists.

The application discloses a method for preparing alanine. The method comprises the following steps: loading pyruvic acid and ammonia water into a reaction kettle loaded with a catalyst, introducing hydrogen into the reaction kettle, and reacting at 90 DEG C to 120 DEG C for 1 to 3 hours to generate alanine through a reductive amination reaction; the catalyst is a core-shell structure, and is composed of a silica shell and a metal core; the metal core is metal M1 and metal M2, and is Ni and Co respectively; the total molar amount of Ni and Co accounts for 75% to 91% of the whole catalyst, and the molar ratio of metal Ni to Co is 1 to 9: 9 to 1. The application avoids the essential safety hazard existing in the original process, and realizes green and sustainable production of alanine.

This invention relates to a carbon nitride-anchored Ru-based catalyst, its preparation method, and its application in the reductive amination of alcohols to prepare amines. The catalyst is based on Ru... n -M n -N x -C indicates that M is a second metal including Pd, Pt, Cu, and Co, and Ru in the catalyst is represented by Ru. 0 With Ru δ+ The coexistence of two valence states, Ru 0 They account for 70%–80% of all Ru species, of which Ru... δ+ The proportion of ruthenium nanoclusters is 20%–30%, and M is the second metal, accounting for 0.01–10 wt% of the total catalyst mass. This invention introduces a nitrogen coordination structure between ruthenium nanoclusters and a carbon support, effectively inhibiting ammonia poisoning and carbon deposition deactivation while maintaining the ruthenium-ruthenium synergistic active sites; it achieves efficient conversion under mild conditions, with significantly improved product yield and selectivity; it is applicable to various types of alcohol substrates, especially suitable for the green synthesis of long-chain aliphatic diamines and functional amine compounds, and has good prospects for industrial application.

The application discloses an organic amine small-molecule catalyst with a chiral ure structure, a preparation method and application, and belongs to the technical field of organic amine compound preparation. The preparation method uses an o-phenylenediamine compound as a starting material, and sequentially performs steps of selective amino protection, ure bond construction, removal of an amino protecting group and reductive amination, so that the target catalyst can be efficiently constructed with good yield. The catalyst is applied to a kinetic ester exchange resolution reaction of a carboxylic acid phthalimide ester, can effectively resolve chiral substrates, and provides an efficient candidate approach for new drug creation.

The application provides a synthesis method of relugolix, comprising the following steps: reacting compound 2 with di-tert-butyl dicarbonate to obtain compound 3; reacting compound 3 with dibromohydantoin to obtain compound 4; reacting compound 4 with dimethylamine hydrochloride to obtain compound 5; hydrolyzing compound 5 to obtain compound 6; condensing compound 6 with 6-methoxy-3-aminopyridazine to obtain compound 7; deprotecting the amino group of compound 7 to obtain compound 8; performing reductive amination on compound 8 with 2,6-difluorobenzaldehyde to obtain compound 9; performing nitro reduction on compound 9 to obtain compound 10; and reacting compound 10 in the presence of carbonyldiimidazole and methoxyamine hydrochloride to obtain relugolix. The synthesis method is more efficient than prior art, avoids potential genotoxic impurities in the prior art, has mild process conditions, high reaction yield in each step, effectively reduces industrial production cost and safety risk, and is suitable for industrial production.

This invention belongs to the field of petroleum extraction technology, specifically relating to a modified sophorolipid surfactant and its preparation method. The preparation method includes: in a weakly acidic solvent, under the action of a reducing agent, sodium benzaldehyde-2,4-disulfonate and a secondary amine undergo a Borch reduction amination reaction to obtain a sulfonated tertiary amine salt; next, in a weakly alkaline environment, the sulfonated tertiary amine salt undergoes a quaternization reaction with epoxy halopropane to obtain an etherifying agent; and finally, under alkaline conditions, the etherifying agent undergoes an etherification reaction with sophorolipid ester to obtain the modified sophorolipid surfactant. The modified sophorolipid surfactant of this invention has the advantages of simple synthesis process, high interfacial activity, and good crude oil viscosity reduction effect.

This invention proposes a method for efficiently catalyzing the reductive amination of alcohols to prepare high-value amines using an alloy catalyst with 100% atom utilization of precious metals. In this catalyst, the precious metal is in a monolayer atomic dispersion form, achieving 100% atom utilization. Compared to existing research and patents, the catalyst preparation method of this invention is simple, significantly improves the utilization rate of precious metals, has lower catalyst costs, and operates under milder reaction conditions, resulting in considerable yields of primary amines. The method of this invention is suitable for batch reactors, the reaction process is environmentally friendly, and the catalyst has good renewability. The catalyst prepared by this invention exhibits good applicability to various types of alcohol substrates. The technical solution of this invention provides a route for the efficient synthesis of high-value primary amines from inexpensive alcohols, with excellent prospects for industrial application.

The present application provides a thermostable reductive aminase, its preparation method and application. Specifically, the present application relates to a thermostable reductive aminase and its functional identification and in vitro directed evolution. The reductive aminase of the present application is a reductive aminase from bacteria (BaRedAm) and its mutants (including a reductive aminase mutant with significantly improved enantiomeric selectivity of product rasagiline). The present application also provides an in vitro reductive amination method, comprising the steps of: (i) in the presence of a thermostable reductive aminase BaRedAm, subjecting (S1) a ketone substrate or an aldehyde substrate to a reductive amination reaction with (S2) an amine substrate. The enzyme and mutant of the present application can be used for in vitro enzymatic synthesis of different products such as enantiomerically pure rasagiline.

The present application relates to a preparation method and application of an important intermediate compound of formula I of a drug Maralixibat. The compound of formula (I) can be synthesized by taking compound (5) or compound (2) as a starting substrate, wherein compound (2) is reacted with compound (S5), compound 5 is obtained after two reductions, compound 5 is sequentially subjected to amino protection, chiral catalytic sulfoxidation, terminal hydroxyl oxidation, cyclization, again sulfoxidation and reductive amination to obtain the compound of formula (I), wherein R 1 and R 2 as defined herein. The present application provides a new method for synthesizing the compound of formula (I) as an important intermediate of the drug Maralixibat by using different starting substrates, and the method of the present application has the advantages of simple steps, mild reaction conditions, high yield and purity, and is suitable for industrial production. In addition, the obtained compound of formula I and the intermediate compounds involved in the synthesis process can be applied to the preparation of the drug Maralixibat.