46 results about "Methylating Agent" patented technology

The invention relates to the field of analysis and detection, and discloses a method for detecting multiple chelating agents in daily chemical products, which comprises the following steps: methylating a to-be-detected sample by using a diazomethane methylation reagent to obtain a to-be-detected solution; carrying out liquid chromatography-mass spectrometry detection on the to-be-detected liquid by adopting a specific elution program to obtain a chromatogram; and performing qualitative and / or quantitative analysis on the chelating agent in the to-be-detected sample according to the chromatogram. By adopting the detection method disclosed by the invention, efficient detection of various chelating agents (including DTPA, DTPMP, EDTMPA, HDTEPA, EGTA, HEDP, EDTA, NTA, GLDA, PBTC, MGDA, IDS, HEEDTA, HPAA, DTPA-OH, CA and ATMP) can be realized, meanwhile, interference of other components in daily chemical products on detection can be avoided, and relatively high detection sensitivity and accuracy of the chelating agents can be realized.

The invention relates to a method for preparing bio-based isosorbide dimethyl ether through resin catalysis, and belongs to the technical field of organic synthesis. Adding corn starch into a sulfuric acid solution, hydrolyzing into glucose, and filtering to obtain a glucose solution; adding a solid acid catalyst into the concentrated glucose solution, and filtering after reaction; carrying out reduced pressure distillation on the filtrate to obtain an isosorbide crude product, and purifying through recrystallization; the preparation method comprises the following steps: adding isosorbide, a methylation reagent and a basic catalyst into a reaction kettle, stirring for reaction, cooling and filtering; and distilling the filtrate, and collecting fractions to obtain high-purity isosorbide dimethyl ether. The solid acid catalyst is sorbic acid based styryl macroporous cation exchange resin; the styryl macroporous cation exchange resin is soaked in sulfuric acid to be activated and then is mixed with sorbic acid chloride, 2-thiophenecarbonyl chloride and zinc chloride to react, and then washing and drying are performed to prepare the solid acid catalyst; the isosorbide dimethyl ether prepared by the method disclosed by the invention is high in purity and relatively high in yield.

The invention discloses a preparation process of 7-AMCA, and relates to the technical field of preparation of 7-AMCA. The method comprises the following steps: adjusting the pH value of a starting material D-7-ACA ultrafiltrate to uniformly crystallize D-7-ACA; growing the crystal to enable the crystal to grow; processing the D-7-ACA crystal subjected to crystal growing into D-7-ACA dry powder; and reacting the D-7-ACA dry powder with a methylation reagent under the action of a strong acid catalyst to obtain a 7-AMCA solution. The method provided by the invention improves the crystallization efficiency, purity and yield of D-7-ACA by optimizing crystallization process parameters of D-7-ACA, including crystal adjustment duration, crystal adjustment stirring speed and crystal growing duration, so that the lactone content in 7-AMCA reaction liquid is reduced, and the product purity of 7-AMCA is improved.

The present application relates to a kind of preparation method of trifluoromethyl pyrazole compound, belong to the technical field of organic synthesis.The specific method is: (1) trifluoroacetyl ethyl acetate is first with hydrazine hydrate cyclization reaction and generates compound of formula III;(2) under the catalysis of base, compound of formula III is reacted with difluoromethylation reagent and generates compound of formula II;(3) compound of formula II is reacted with methylating agent and obtains compound of formula I;The difluoromethylation reagent is difluoro-monochloromethane or sodium difluoro-monochloroacetate;The methylating agent is chloromethane, bromomethane, iodomethane, dimethyl sulfate or dimethyl carbonate.The present application is prepared by changing reaction route, and the higher-priced raw material methylhydrazine is replaced, and isomer impurity is no longer generated in the product prepared.Not only raw material cost is reduced, but also the purity of product is improved.

The present invention provides a method for preparing an α-cadaverine-based compound of the following general formula (3): wherein R 2 represents a monovalent hydrocarbon group having 1 to 9 carbon atoms, the method comprising: making a 3,5,5-trimethyl-3-cyclopentene compound of the following general formula (1): wherein R 2 As defined above, and X represents a leaving group, and the methylating agent of the following general formula (2): wherein M represents Li, Mg, Z 1 、ZnZ 1 、Cu、CuZ 1 or CuLiZ 1 , and Z 1 represents a halogen atom or a methyl group, undergoing a nucleophilic substitution reaction to form an α-cadaverine-based compound (3). The present invention also provides a method for preparing a γ-cadaverine-based compound of the following general formula (4): wherein R 2 represents a monovalent hydrocarbon group having 1 to 9 carbon atoms, and the method comprises: subjecting the thus obtained α-cadaverine-based compound (3) to positional isomerization reaction at the double bond to form a γ-cadaverine-based compound (4). #imgabs0#

The invention discloses a method for pyridine alkylation, comprising the following steps: using anhydrous titanium chloride and anhydrous ferric chloride solution as raw materials, adding a dispersant and then heating and stirring evenly, then adding ammonia to adjust the pH to a fixed value, grinding and sieving to obtain a catalyst support; immersing an equal volume of the catalyst support into a rare earth metal oxide solution dissolved in dilute sulfuric acid for aging, grinding and sieving to obtain a rare earth metal-modified solid superacid catalyst; after activation of the rare earth metal-modified solid superacid catalyst, the reaction temperature is lowered to be loaded into a fluidized bed reaction tube, pyridine and dimethyl carbonate are mixed and fed, and nitrogen is introduced into the air inlet valve at the same time. The raw material mixed nitrogen reacts in the catalyst layer to achieve high-selectivity pyridine alkylation. Using pyridine and green methylating agent dimethyl carbonate as raw materials, under the action of a rare earth metal-modified solid superacid catalyst, 2-methylpyridine can be synthesized with high selectivity.

The application discloses an amplification preparation method of dimethylheptyl methylphosphonate, and belongs to the technical field of medical intermediates. The core point of the application is that 2-octanol and phosphorus trichloride are used as raw materials, and tri-2-octyl phosphite is generated in an organic solvent in the presence of a catalyst A, then the tri-2-octyl phosphite is reacted with a methylating agent in the presence of a catalyst B to generate dimethylheptyl methylphosphonate. The method avoids the use of dangerous reagents and expensive reagents, reduces the raw material cost, reduces the generation amount of isomers, improves the reaction yield, greatly reduces the amount of three wastes, and makes the whole preparation process more green and environment-friendly. The process is simple and reliable, easy to industrial production, and provides a new reaction path for the synthesis of dimethylheptyl methylphosphonate.

This invention discloses a method for iron-catalyzed methylation of quinone compounds, comprising the following steps: in a solvent, using 2-aryl-2-propanols as methylating agents, peroxides as oxidants, iron as catalysts, and amino acids or their derivatives as ligands, oxidizing the C(sp) group of aromatic compounds. 2 The H-bond undergoes methylation to generate methyl-substituted quinone compounds. This invention offers advantages such as readily available, inexpensive, and environmentally friendly catalysts; readily available, inexpensive oxidants that do not generate hazardous waste; mild, stable, and inexpensive methylating agents; mild reaction conditions with high selectivity and high yield; widely available and stable substrates; good compatibility of substrate functional groups and a wide range of substrate applications; compatibility with complex molecules and natural products, enabling effective methylation of quinone compounds. Under optimized reaction conditions, the yield of the target product after separation can reach 80%.

This invention discloses a method for synthesizing potassium 4-methoxysalicylate based on supramolecular-assisted methylation, belonging to the field of organic synthesis technology. The process is based on supramolecular chemistry principles and includes the following steps: (1) Preparation of a macrocyclic host molecule-methylating agent complex loaded with a methylating agent: The macrocyclic host molecule and the methylating agent are reacted at pH 7-9 and 25-40℃ to form a complex solution; (2) One-pot preparation of the target product: 2,4-dihydroxybenzoic acid is salted with potassium hydroxide, potassium carbonate is added, and the above complex solution is added dropwise. A selective methylation reaction is carried out at 55-65℃. After the reaction is complete, post-treatment yields the product. This invention utilizes the molecular recognition function of the macrocyclic host to achieve highly selective methylation of the 4-hydroxyl group under mild conditions. This process has the advantages of simple operation, high safety, low waste, and recyclable host molecules. The yield of potassium 4-methoxysalicylate can reach over 85%, and the purity exceeds 99.0%.

The present invention provides a method for preparing enantiopure α-methoxyphenylacetic acid. The method comprises: using (R / S)-mandelic acid as the main raw material, performing an O-alkylation reaction with a methylating agent in the presence of an alkaline reagent, followed by purification and dissociation using an organic base to obtain enantiopure α-methoxyphenylacetic acid with a purity of up to 99.0%. The method achieves a maximum yield of 88.6% in an aprotic mixed solvent. This process reduces the amount of methylating agent used and increases the conversion rate to 99.5%. The organic base salt formation purification is efficient, produces a good crystal form, and is easily filtered. The process is simple, highly safe, and suitable for industrial-scale production.

The invention discloses a synthesis method of a metribuzin isomer. Triazinone is used as a raw material, dimethyl carbonate is used as a methylation reagent, and the metribuzin isomer is prepared under base catalysis. The synthesis method is simple and convenient to operate, the used dimethyl carbonate replaces a traditional virulent methylation reagent, virulent by-products are eliminated, the method has the characteristics of low cost and environmental protection, a standard substance is provided for qualitative and quantitative analysis of impurities in metribuzin production, an optimized technical scheme is provided for production of triazinone herbicides, and the method is suitable for industrial production. The method is suitable for industrial application.

This invention discloses a method for preparing diosmin impurity compounds and their application, relating to the field of pharmaceutical impurity preparation technology. The preparation method includes the following steps: S1, preparation of compound IM-1: compound SM-1 and a methylating agent are heated under alkaline conditions to obtain compound IM-1; S2, preparation of compound formula 1: compound IM-1 is added to an alcohol solution, and an inorganic base is added under stirring. After the addition is complete, the mixture is kept warm and stirred, then cooled to 15-20°C, and dilute hydrochloric acid is added dropwise until the pH reaches 6.5-7. The mixture is concentrated to obtain the crude product of formula 1, and finally purified by thin-layer chromatography to obtain the pure product of formula I. This product can be used as a reference standard for the quality control of diosmin raw material, which helps to obtain a higher quality product.

The invention relates to a preparation method of ceftriaxone sodium, which comprises the following steps: (1) mixing aminothiazole acetic acid, an organic solvent and ethylene glycol, dropwise adding thionyl chloride to carry out primary reaction, concentrating the reaction liquid after the reaction is finished, then adding the organic solvent again and dropwise adding thionyl chloride to carry out secondary reaction to obtain chloroethanol aminothiazole acetate; (2) reacting the chloroethanol aminothiazole acetate with 7-ACT in the presence of immobilized penicillin acylase for synthesis to generate a first intermediate product; (3) reacting the first intermediate product with tert-butyl nitrite under an acidic condition to generate a second intermediate product; (4) reacting the second intermediate product with a methylation reagent under the action of a base catalyst to generate ceftriaxone acid; and (5) reacting the ceftriaxone acid with an inorganic base to generate the ceftriaxone sodium. The preparation method disclosed by the invention is mild in reaction, green and environment-friendly, high in yield and high in purity.

The application belongs to the field of medicine and provides a new method for preparing a lumerabenzine intermediate compound shown in formula II. The method is that a compound of formula I is reacted with a methylating agent in the presence of an acid binding agent, an organic solvent and water to prepare a compound of formula II. The reaction can be carried out at a lower temperature, high-pressure reaction containers and flammable and explosive materials are avoided, energy consumption is lower, post-reaction treatment is simple, and the method is suitable for industrial production.

This invention provides a method for synthesizing 4-methoxypyrrole derivatives, relating to the field of organic chemical intermediate synthesis technology. The 4-methoxypyrrole derivative is prepared by first reacting m-difluorobenzene as a starting material with oxaloyl chloride monoester under Lewis acid catalysis. The reaction product then undergoes cyclization with aminopropionitrile under alkaline conditions. The subsequent product reacts with methanol in a boron trifluoride complex, followed by methylation with a methylating agent under alkaline conditions. This invention overcomes the shortcomings of existing technologies, providing a simple, low-cost, and easily industrialized method for preparing 4-methoxypyrrole derivatives. It offers advantages such as readily available raw materials, high yield, good quality, simple operation, and suitability for industrial production.

The present application relates to a kind of toluene, methylating agent is obtained in the production method of paraxylene concentration greater than 80% of dimethylbenzene with water vapor as medium to promote reaction.The main problem is that in the existing toluene shape selective methylation fixed bed reaction process, hydrogen and / or nitrogen are used as carrier gas to promote the reaction, which causes high fixed equipment investment, high device material requirements and other problems.The present application solves the problem by shape selective methylation of toluene and methylating agent, adding water vapor instead of hydrogen and / or nitrogen as carrier gas as medium to promote the reaction, and the catalyst para-selectivity is 80-95%, the laboratory life can reach 1000 hours, which can better solve the problem.The method has the advantages of high product purity, no complex separation, simple operation, low fixed asset investment, low material consumption, etc., and can be used for the industrial production of paraxylene.

This invention provides an ionic polymer based on fluorophenyl crosslinked polyarylpiperidine, its preparation method, and its applications, belonging to the field of polymer materials technology. The preparation method includes the following steps: placing a fluorophenyl crosslinking agent, an N-substituted R-4-piperidine, a ketone reactant, and an aromatic reactant in a first organic solvent, adding an acid catalyst to react and obtain a polymer solution with a piperidine structure; subsequently, washing, filtering, and drying in a first precipitant to obtain a polymer powder with a piperidine structure; then dissolving it in a second organic solvent, adding a methylating agent and a basic reagent to react and obtain a quaternized polymer solution; subsequently adding it to a second precipitant, washing, filtering, and drying to obtain an ionic polymer containing fluorophenyl crosslinked polyarylpiperidine. This invention provides a simple preparation method with low raw material costs and is suitable for large-scale production, applicable to fields such as water electrolysis.

This invention belongs to the field of new materials and polymer materials, and relates to an in-situ ATRP-initiated organic / inorganic hybrid anion exchange membrane and its preparation method. The specific steps are as follows: using brominated carbon nanotubes as an initiator, the atom transfer radical polymerization of N,N-dimethylaminomethyl methacrylate is initiated; further, a quaternary ammonium functional ion is added through a Mensutkin reaction with a methylating agent, thereby obtaining an organic / inorganic hybrid anion exchange membrane material initiated by in-situ atom transfer radical polymerization (ATRP). The anion exchange membrane material prepared by this invention possesses both ionic conductivity and dimensional stability, exhibiting excellent performance in alkaline water electrolysis and fuel cells, and can also be used in anion dialysis, etc. This invention is simple and easy to implement, the raw materials can be industrially produced, and it has broad application prospects.

The application discloses a method for removing half ester in bisphenol A bis(diphenyl phosphate), relates to the technical field of organic synthesis, and has the following steps: mixing bisphenol A bis(diphenyl phosphate) material containing half ester with a methylating agent in the presence of a Lewis acid catalyst to make P-OH groups in the half ester undergo a methylation reaction, wherein the methylating agent is selected from one or more of dimethyl phosphate, dimethyl carbonate and dimethyl sulfate; and performing vacuum distillation on the reaction material after the reaction is completed to remove unreacted methylating agent and by-products, and further performing solvent dissolution, acid washing, alkali washing, water washing and desolvent treatment. The method has the beneficial effects that the half ester impurities containing acidic P-OH groups are converted into corresponding phosphate esters through the methylation reaction, and the half ester content and acid value in the BDP product are reduced.

The invention relates to the field of N-methylaniline production, and discloses a method for continuously producing N-methylaniline. The method comprises the following steps: synthesizing N-methylaniline, regenerating a solvent of a spent catalyst, and returning the regenerated catalyst to the synthesis of N-methylaniline for reuse, the synthesis of the N-methylaniline comprises the following steps: in the presence of a fresh catalyst, reacting a methylation reagent with aniline to obtain a spent catalyst; the fresh catalyst comprises a molecular sieve, an inorganic oxide and a modified component, and the modified component is selected from at least one of copper, alkali metal, alkaline earth metal and iron; the sum of the weak acid amount and the middle weak acid amount of the fresh catalyst accounts for more than 80% of the total acid amount; the regeneration of the solvent of the spent catalyst comprises the following steps: sequentially carrying out first-stage solvent regeneration, second-stage hydrogen regeneration and third-stage solvent hydrogen regeneration on the spent catalyst. According to the method, complete regeneration of the deactivated catalyst can be realized, the stability of the catalyst is improved, and long-period operation of the device and continuous production of N-methylaniline are realized.

The application discloses a process for the preparation of saflufenacil comprising reacting 2-chloro-5-(2,6- dioxo-4-(trifluoromethyl)-3,6-dihydropyrimidin-l(2H)-yl)-4-fluoro-N-(N-isopropyl-N- methylsulfamoyl)benzamide with a methylating agent in the presence of a phase transfer catalyst to obtain a final reaction mixture comprising saflufenacil and the phase transfer catalyst, characterized in that the phase transfer catalyst is removed or partially removed before separating or purifying saflufenacil.

The invention discloses light-color lignin and an oxidation preparation method thereof, and belongs to the technical field of industrial by-product recycling. The method for preparing light-color lignin through oxidation comprises the following steps: dissolving industrial recovered lignin in a sodium hydroxide solution, adding a methylation reagent, and carrying out first heating and stirring reaction to obtain methylated lignin; adding the sodium hydroxide solution into the methylated lignin again, then adding hydrogen peroxide, and carrying out secondary heating and stirring reaction to obtain light-colored lignin; wherein the methylation reagent comprises dimethyl sulfate and / or methyl iodide. According to the method, methylation pretreatment is combined with a hydrogen peroxide oxidation bleaching process, so that the defect of dark color of industrial lignin can be effectively overcome.

The invention relates to the technical field of organic synthesis, in particular to a preparation method of difluropyrazole acid, which comprises the following steps: reacting hydrazine hydrate serving as a raw material with di-tert-butyl dicarbonate to generate tert-butyloxycarboryl hydrazine, reacting the tert-butyloxycarboryl hydrazine with a compound obtained by reacting unsaturated ester with 2, 2-difluoroacetyl halide, and removing Boc protecting groups from the obtained product to obtain the difluropyrazole acid. And then carrying out an N-methylation reaction with an N-methylation reagent to obtain the difluopyrazole acid. The yield and purity of the difluopyrazole acid are improved by introducing a protecting group and adjusting a reaction route, and the preparation method has the advantages of low cost, low toxicity, high safety, mild reaction conditions and suitability for industrial production by replacing a highly toxic product methylhydrazine with the cheap hydrazine hydrate.

The invention relates to the field of N-methylaniline production, and discloses a method for producing N-methylaniline. The method comprises the following step: in the presence of a catalyst, reacting reaction raw materials, namely a methylation reagent and aniline, the catalyst comprises a molecular sieve, an inorganic oxide and a modified component, and the modified component is selected from at least one of copper, alkali metal, alkaline earth metal and iron; wherein the sum of the amount of weak acids and the amount of medium and weak acids in the catalyst accounts for more than 80% of the total acid amount. When the method provided by the invention is used for producing the N-methylaniline, the selectivity of the target product N-methylaniline is relatively high.

This invention discloses a method for preparing cyclopentanone and its intermediates. Specifically, this invention discloses a method for preparing a compound as shown in formula (II), which includes the following steps: Step S1: In a solvent, under the action of a base, cyclopentanone undergoes a methylation reaction with a methylating agent to prepare a crude compound as shown in formula (I); Step S2: In a solvent, under the action of a base, the crude compound as shown in formula (I) undergoes a condensation reaction with p-chlorobenzaldehyde to prepare a compound as shown in formula (II).

The application relates to a phenanthridone skeleton-containing compound and a preparation method and application thereof, and belongs to the technical field of chemical synthesis. The preparation method of the phenanthridone skeleton-containing compound comprises the following steps: S1, a substitution reaction of compound 1 and an alkylating agent to obtain compound 2; S2, hydrolysis of an ester bond of compound 2 to obtain compound 3; S3, reaction of compound 3 and compound 4 to obtain compound 5; S4, a substitution reaction of compound 5 and an alkylating agent to obtain compound 6; S5, intramolecular coupling reaction of compound 6 to obtain compound 7; S6, reduction reaction of compound 7 to obtain compound 8; S7, reaction of compound 8 and a methylating agent to obtain compound 9; and S8, reaction of compound 8 and an alkylating agent to obtain compound 10. The application provides a simple and mild synthesis method for natural active products which can only be extracted from secondary metabolites of marine fungi aspergillus and have limited sources.

The application discloses a kind of 4,16 bis (m-methoxyphenyl) -[2,2] -p-xylene ring diatomic for preparing parylene coating resistant to electrochemical corrosion and its preparation method and application, specifically relates to a kind of 4,16 bis (m-methoxyphenyl) -[2,2] -p-xylene ring diatomic, its preparation method includes the following steps: S1, p-xylene ring diatomic is reacted with liquid bromine in the presence of catalyst, first solvent, and intermediate 1 is obtained;S2, intermediate 1 is reacted with 3-hydroxyphenylboronic acid in the presence of base salt, palladium catalyst and second solvent, and intermediate 2 is obtained;S3, intermediate 2 is reacted with methylating agent in the presence of base salt, third solvent, and the ring diatomic monomer is obtained.The phenyl parylene coating prepared from the above monomer shows excellent resistance to electrochemical corrosion, compared with the corrosion-resistant coating formed by the existing parylene monomer, not only the corrosion current density is low, and corrosion potential is high, has good application prospect in electronic product protection or medical instrument protection and the like.

This invention relates to carbon-13 labeled psychoactive substances, the chemical structural formula of which is: . This invention also provides a method for preparing the aforementioned carbon-13 labeled psychoactive substances, comprising the following steps: (1) 13 C-C3-alanine reacts with Boc2O and a methylating agent to form N-methyl-N-Boc- 13 (2) The product obtained in step (1) is reacted with N,O-dimethylhydroxylamine to obtain an intermediate; (3) The intermediate obtained in step (2) is reacted with a phenyl nucleophile to obtain 13 C-C3-2-N-Boc-methylamino-1-phenyl-1-propanone; (4) The product obtained in step (3) is subjected to a Boc protecting group removal reaction to obtain the carbon 13-labeled psychoactive substance. The present invention also provides the use of the carbon 13-labeled psychoactive substance in detecting the content of methcathinone in biological or environmental samples.

This invention discloses a method for preparing deuterated methyl ether compounds based on visible light / nickel synergistic catalysis. A mixed solution comprising a trideuterium-containing methylating agent (Formula 1), an aryl halide (Formula 2), a photocatalyst and a nickel catalyst, a base additive, and a solvent is reacted in a reaction apparatus irradiated with visible light to produce an aryl deuterated methyl ether compound (Formula 3). This method utilizes inexpensive metal catalysts and low-toxic solvents, uses visible light as an energy source, and is carried out at room temperature. The reaction conditions are clean, green, and environmentally friendly, while achieving a product yield of up to 85%. This method effectively overcomes the problems of traditional synthetic pathways, such as complex operations, long reaction times, the need for expensive catalysts, and low atom economy. #imgabs0#

Anticancer conjugates combining a DNA methylation agent and an anticancer drug are provided herein, as well as uses of the same in cancer treatment.