85 results about "Dimethyl sulfate" patented technology

The present invention discloses an imidazole derivative, a preparation method thereof, and an application, belonging to the field of organic chemistry. The preparation method of the imidazole derivative of the present invention includes: adding compound 2a and dimethyl sulfate into an organic solvent, heating and reacting to obtain compound 3a; wherein, compound 2a is prepared by adding compound 1a, TrtCl, and a base reagent into a solvent, controlling the temperature at 0-10 °C, mixing evenly and reacting. The present invention also further prepares 2-(1-methylimidazol-5-yl)ethylamine (4a) by using the imidazole derivative. The present invention selects dimethyl sulfate as a methylation reagent and cooperates with a specific protecting group design to achieve the efficient preparation of 2-(1-methylimidazol-5-yl)ethylamine, with a total yield of 82.4%.

The invention discloses a continuous kettle type nitromethane production process, and relates to the technical field of basic chemical raw material synthesis and flow chemical reaction process control, which comprises the following steps: quantitatively and continuously pumping a temperature-regulated sodium nitrite mixed solution into a raw material mixer in a closed-loop automatic control mode through a variable-frequency feeding pump matched with a mass flow meter; synchronously, quantitatively and continuously pumping dimethyl sulfate into the raw material mixer in a closed-loop automatic control manner by matching a feeding pump with a stop valve and a mass flow meter, and uniformly mixing the two raw materials in the raw material mixer according to the stoichiometric molar ratio of the dimethyl sulfate to the sodium nitrite, according to the tandem type segmented design, each reaction kettle can be subjected to customized temperature field control and heat transfer design specially aiming at the special thermodynamic and dynamic requirements of the reaction stage where the reaction kettle is located, the heat transfer efficiency of the whole system is greatly improved, and due to the fact that reaction heat is taken away timely and accurately, the heat transfer efficiency is greatly improved. And a by-product generation path induced by local abnormal high temperature is effectively restrained.

The invention relates to an L-proline heterocyclic intermediate, alpha-methyl-L-proline hydrochloride and a preparation method thereof, which comprises the following steps: step 01, cyclization upper protection: taking L-proline as a raw material, which is shown in a formula (1), to react with trichloracetic aldehyde hydrate under an acidic condition, and performing upper protection to obtain a heterocyclic intermediate as shown in a formula (2); the molar weight of chloral hydrate is 1-2.5 times of the molar weight of the L-proline shown in the formula (1), preferably 1.5 times of the molar weight of the L-proline shown in the formula (1). 02, methylation: reacting the heterocyclic intermediate as shown in the formula (2) obtained in the step 01 with lithium diisopropylamide, and after the reaction is completed, adding dimethyl sulfate for methylation to obtain an intermediate as shown in a formula (3); 03, deprotection: adding the intermediate as shown in the formula (3) obtained in the step 02 into a deprotection reagent for hydrolysis so as to obtain the alpha-methyl-L-proline hydrochloride as shown in the formula (4), so that the problems that the preparation cost of the existing alpha-methyl-L-proline hydrochloride is relatively high and the yield is relatively low can be solved.

The invention belongs to the technical field of drug synthesis, and relates to a dotenorad synthesis method, which comprises: weighing 100 g of a compound 1 as a raw material, and carrying out a substitution reaction with dimethyl sulfate to obtain a compound 2; taking the compound 2 as a raw material, and carrying out esterification reaction with methanol under an acidic condition; taking the compound 3 as a raw material, and obtaining a compound 4 after chlorination; hydrolyzing the compound 4 serving as a raw material to obtain a compound A; reacting the compound 5 serving as a raw material with a formaldehyde aqueous solution to obtain a compound 6; taking the compound 6 as a raw material, and performing thioether oxidation to obtain a compound B; taking a compound A as a raw material, and carrying out amide condensation reaction with a compound B to obtain a compound C; and 6, demethylating the compound C serving as a raw material under the action of lithium chloride to obtain a compound D, namely the final product dotenorad. According to the synthesis method of dotenorad, oxidation after condensation is not needed, generation of by-products is avoided, raw materials are low in cost and easy to obtain, and the synthesis method is suitable for industrial production.

The invention provides a method for detecting trace dimethyl sulfate in nicergoline, which comprises the following steps of: carrying out derivatization reaction on an azacyclo-compound serving as a derivatization agent and dimethyl sulfate in nicergoline to generate a derivatization product, and determining the amount of the derivatization product by using a high performance liquid chromatograph-mass spectrometer, therefore, the content of dimethyl sulfate in nicergoline is obtained. Compared with the prior art, the detection method provided by the invention has the characteristics of good specificity, high sensitivity, good reproducibility and the like, and makes up the vacancy of how to detect trace dimethyl sulfate in nicergoline in the prior art.

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 application relates to a kind of preparation methods of 2-methylamino-3-formylpyridine, comprising the following steps: 3-cyanopyridine and dimethyl sulfate are heated to reflux reaction in organic solvent I, then base is added, continue to react under heating reflux condition, and obtain intermediate product 2-methylamino-3-formylpyridine.The raw material used in the preparation method of the present application is cheap and easy to obtain, the preparation process has few side reactions, and is easy to purify.Only the steps of extraction and heavy crystallization are needed to achieve high purity, and strict control of anhydrous reaction conditions is not required.The yield and purity are high, and the prepared 2-methylamino-3-formylpyridine is suitable for industrial large-scale production of 2-methylamino-3-hydroxymethylpyridine, and further preparation of eslicarbazepine acetate and / or eslicarbazepine acetate sulfate.

The invention relates to a catalyst for preparing anisole through phenol methanol etherification as well as a preparation method and application of the catalyst. The catalyst takes aluminum phosphate as a carrier and is doped with zirconium oxide; on the basis of the mole number of Al, the mole ratio of P to Al is (0.05-2): 1, and the mole ratio of Zr to Al is (0.08-0.20): 1. Dropwise adding the aluminum-zirconium mixed aqueous solution into the phosphorus source aqueous solution, stirring, standing and washing to obtain a solid sample; and drying and roasting the solid sample to obtain the aluminum phosphate catalyst. Under the action of the catalyst, phenol and methanol are catalyzed to generate anisole. Compared with the prior art, the phenol conversion rate is greater than or equal to 50%, the anisole selectivity is greater than or equal to 85%, highly toxic dimethyl sulfate and a large amount of alkali are not needed, the process is green, the cost is low, separation is simple, and the method is suitable for large-scale industrial production of anisole.

The invention relates to an application of N, N-diisopropylethylamine as an organic acid binding agent in preparation of dimethyl sulfate, N, N-diisopropylethylamine is used for purifying a crude dimethyl sulfate product into a dimethyl sulfate product, N, N-diisopropylethylamine is added into the crude dimethyl sulfate product, stirring reaction is carried out, and the N, N-diisopropylethylamine is obtained. And carrying out reduced pressure distillation or reduced pressure rectification purification to obtain a dimethyl sulfate product. According to the method, N, N-diisopropylethylamine is used as an organic acid-binding agent, so that various acidic residues in the crude dimethyl sulfate product can be effectively removed, the acidity of the dimethyl sulfate product is reduced, and the product quality is correspondingly improved. And moreover, the residual liquid amount of dimethyl sulfate can be reduced, the treatment amount of three wastes is reduced, and the method is suitable for industrial production of high-purity dimethyl sulfate.

The invention discloses modified lignin as well as a preparation method and application thereof, the preparation method comprises the following steps: adding lignin into a reaction kettle, adding an organic solvent, and stirring and dispersing; the preparation method comprises the following steps: adding an alkaline agent into a reaction kettle, stirring, condensing, refluxing, heating to 80-110 DEG C, adding a modifier A which is dimethyl carbonate or dimethyl sulfate, and reacting for 3-6 hours; after the reaction is finished, a modifier B is added for continuous reaction, negative pressure distillation is performed to remove the organic solvent, modified lignin is obtained, and the modifier B is epichlorohydrin. According to the method, the polarity of the lignin is remarkably reduced through two-step modification, the compatibility and dispersity of the lignin and a rubber matrix are enhanced, meanwhile, introduced active groups can be chemically bonded with rubber molecules, and the reinforcing effect is improved. The prepared modified lignin can be used as a rubber reinforcing agent, the tensile strength and hardness of a rubber product are effectively improved, the process is environment-friendly, the solvent can be recycled, and the method is suitable for preparing a green high-performance rubber material.

The application discloses a preparation method of triclabendazole, and relates to the technical field of raw medicine synthesis. The method comprises the following steps: taking 4-chloro-5-(2,3-dichlorophenoxy)-2-nitroaniline as raw material, and sequentially performing reduction in an iron powder ethanol system, ring closure with a sulfur-containing ring closure reagent, methylation with dimethyl sulfate, and crystallization and purification in ethanol to obtain triclabendazole finished products. In the reaction process, iron mud is removed through pressure filtration, ethanol is recovered through distillation, and the ring closure intermediate is precipitated under acidic conditions. The process condition is clear, the operation is simple, the emission of hazardous waste can be reduced, the utilization rate of solvents and the purity of products can be improved, and the method is suitable for industrialized production of triclabendazole raw medicine.

The method for manufacturing an intermediate compound for shikonin synthesis of the present invention comprises the steps of: reacting 1,5-dihydroxynaphthalene with dimethyl sulfate to prepare 1,5-dimethoxynaphthalene; reacting 1,5-dimethoxynaphthalene with N-bromosuccinimide (NBS) to prepare 1,5-dibromo -4,8-dimethoxynaphthalene; introducing a methoxy group into 1,5-dibromo-4,8-dimethoxynaphthalene using copper iodide (CuI) and 1,10-phenanthroline as a catalyst to prepare 1,4,5,8-tetramethoxynaphthalene; performing formylation of 1,4,5,8-tetramethoxynaphthalene using phosphoryl chloride (POCl3) to prepare 2-formyl-1,4,5,8-tetramethoxynaphthalene; and forming a boron complex using pinacolborane (HBpin) and 3,3-dimethylallyl bromide and reacting the boron complex with 2-formyl -1,4,5,8-tetramethoxynaphthalene to prepare a prenylated shikonin intermediate. Compared to conventional synthetic methods, the method of the present invention offers milder reaction conditions, shorter reaction time, and improved yield, thereby greatly enhancing the economic feasibility of shikonin synthesis.

The invention relates to a method for efficiently preparing flurbiprofen based on a Suzuki-Miyaura coupling reaction. The preparation method comprises the following steps: taking ethyl cyanoacetate as a raw material, and carrying out methylation reaction on the ethyl cyanoacetate and methyl iodide or dimethyl sulfate to prepare racemic ethyl 2-cyanopropionate; the racemic ethyl 2-cyanopropionate and 4-bromine-2-fluorobiphenyl are subjected to a similar Suzuki-Miyaura reaction under the combined action of a zero-valent palladium metal catalyst, a metal stabilizer phosphine ligand and alkali, and the racemic ethyl 2-cyano-2-(2-fluoro4-biphenyl) propionate is obtained; and carrying out hydrolysis and decarboxylation on the racemic 2-cyano-2-(2-fluoro-4-biphenyl) ethyl propionate to obtain racemic 2-(2-fluoro-4-biphenyl) propionic acid, namely, the flurbiprofen. The process route comprises three steps of reaction, materials are cheap and easy to obtain, operation is simple, aftertreatment is convenient, and the obtained product is high in purity.

The application belongs to the technical field of compound synthesis, and particularly relates to a preparation method of dipyrone with controlled content of 4-N methylene sulfonic acid sodium dipyrone impurity, which comprises the following steps: dissolving 4-formylaminoantipyrine in water, and then adding dimethyl sulfate and lye to react to obtain a methylation liquor; the obtained methylation liquor is hydrolyzed and neutralized, and then is left to stand and separate into layers, the upper 4-methylaminoantipyrine oil is cooled and crystallized to obtain 4-methylaminoantipyrine solid; the obtained 4-methylaminoantipyrine solid, ethanol, sodium pyrosulfite, activated carbon and formaldehyde are mixed to react to obtain dipyrone; the mass percentage of 4-aminoantipyrine in the 4-formylaminoantipyrine is not more than 1.5%. The content of 4-N methylene sulfonic acid sodium dipyrone (unknown impurity) in the prepared dipyrone is less than or equal to 0.05%, which meets the requirements of the European Pharmacopoeia.

The invention discloses a continuous preparation technology of O-methyl-N-nitroisourea, and belongs to the technical field of fine chemical engineering. The O-methyl-N-nitroisourea is prepared by using the continuous flow reactor, compared with the prior art, the whole reaction process is completely sealed, the phenomena of running, emitting, dripping and leaking in the reaction process can be completely eradicated, meanwhile, the dosage of dimethyl sulfate is reduced, and personnel injury caused by leakage of highly toxic dimethyl sulfate can be effectively avoided; according to the invention, all the materials are fed in a liquid phase form, the preparation process of a sulfuric acid solution and a mixed acid solution is avoided, the operation procedures are reduced, the dissolution heat of sulfuric acid is effectively utilized, and the temperature rise is accelerated; the reaction can be completed by using a relatively low amount of concentrated nitric acid, and compared with fuming nitric acid, the cost of the concentrated nitric acid is greatly reduced; the whole operation process is simple, side reactions are few, the yield is high, the method is suitable for industrial production, and compared with a traditional intermittent kettle reaction, the method has great advantages.

The present invention provides a method for preparing O-methyl-N-benzyloxycarbonyl-L-homoserine, which relates to the field of organic synthesis. The preparation method of the present invention comprises the following steps: (1) reacting compound 1, a base, and di-tert-butyl dicarbonate in a solvent to obtain compound 2; (2) reacting compound 2, a base, and dimethyl sulfate in a solvent to obtain compound 3; (3) reacting compound 3 with thionyl chloride in a solvent to obtain compound 4; (4) reacting compound 4 with benzyl chloroformate in an alkaline environment in a solvent to obtain compound 5; (5) reacting compound 5 with a base in a solvent to obtain. The raw materials used in the present invention are easily available and low-priced, the reaction conditions are mild, the intermediate reaction steps do not require purification, and column chromatography separation is not required, and the steps are simple; and the reaction steps of the present invention are safe, non-toxic, and environmentally friendly. The product obtained by the preparation method of the present invention has high purity, high yield, low cost, is suitable for scale-up production, and has broad application prospects. #imgabs0#

The invention provides a method for catalytic continuous synthesis of aryl methyl ether, and belongs to the field of aryl methyl ether. The method for catalytically and continuously synthesizing the aryl methyl ether is carried out in a manner of combining continuous reaction and continuous rectification. According to the method for catalytically and continuously synthesizing the aryl methyl ether, the continuous production of the aryl methyl ether can be realized while dimethyl sulfate is not adopted and a large amount of high-toxicity wastewater and solid wastes are prevented from being generated in the production process, and the continuous production of the aryl methyl ether is mild in reaction condition, low in requirement on production equipment, small in production risk and high in production efficiency; the yield of the aryl methyl ether prepared through large-scale production is high, and large-scale industrial production is facilitated.

The invention relates to the technical field of methyl isocyanate, in particular to a methyl isocyanate preparation method based on a dimethyl sulfate route, which comprises the following steps: raw material preparation: raw materials comprise sodium cyanate, orthodichlorobenzene and dimethyl sulfate, the mass ratio of sodium cyanate to dimethyl sulfate is 1: (0.6), and the mass of orthodichlorobenzene is 3-5 times that of sodium cyanate; the method comprises the following steps: raw material pretreatment: respectively pretreating sodium cyanate, o-dichlorobenzene and dimethyl sulfate for later use; according to the method, uniform slurry is formed through grinding, the specific surface area of sodium cyanate particles is increased, full contact between the sodium cyanate particles and dimethyl sulfate is promoted, the effect of improving the reaction efficiency is achieved, after heating and negative-pressure dehydration treatment, hydrolysis of dimethyl sulfate and hydrolysis side reaction of methyl isocyanate can be prevented through reduction of moisture, and therefore generation of impurities is reduced, and the product quality is improved. The product purity is improved, the product is prevented from being decomposed or subjected to secondary reaction at high temperature due to lower rectification temperature, and the product stability is ensured.

The present application relates to a kind of preparation methods of 3,4-dihydroxy-5-methoxybenzoic acid methyl ester, with gallic acid as raw material, it is reacted with trimethyl orthoformate or trimethyl orthoacetate, trimethyl orthoformate or trimethyl orthoacetate can realize the protection of adjacent diphenol hydroxyl on one hand, on the other hand, carboxyl esterification and 5-hydroxyl are methylated, form the methyl ester of 5-phenolic hydroxyl methylation and 3,4-orthoester protection benzoic acid shown in formula 1a or formula 1b, further by acidic solution treatment, deprotection is carried out, and the target product 3,4-dihydroxy-5-methoxybenzoic acid methyl ester is prepared.The preparation method is mild in reaction condition, process is simple, easy to operate, product yield and purity are high, solve the wastewater problem in borax protection method, and avoid using toxic dimethyl sulfate for methylation, process condition is simple, easy to operate, convenient for industrialization, with very high application value.

The invention belongs to the field of synthesis of drug intermediates, and discloses a process for industrially producing 2-allyl-3-methoxybenzaldehyde. The synthesis method comprises the following three steps: 1, alkylation reaction: reacting a raw material 3-hydroxybenzaldehyde with allyl bromide under an alkaline condition to obtain an allyl ether intermediate (3-allyl ether benzaldehyde); and 2, Claisen rearrangement reaction of the allyl ether intermediate: under a brand new flowing chemical reaction device (240 DEG C, 2MPa back pressure), dissolving the raw materials in a solvent, pumping the solvent into a microchannel, carrying out rearrangement reaction, and recrystallizing to remove an isomer, so as to obtain the intermediate 2-allyl-3-hydroxybenzaldehyde. And 3, methylation reaction: enabling the 2-allyl-3-hydroxybenzaldehyde to react with dimethyl sulfate under an alkaline condition, so as to obtain the product 2-allyl-3-methoxybenzaldehyde. The total yield of the three steps is 40%. According to the process, the raw materials are low in price and easy to obtain, the process operation is simple and convenient, and the process is suitable for industrial production of the 2-allyl-3-methoxybenzaldehyde.

The invention discloses a preparation method of N1, N2-dimethylbenzene-1, 2-diamine, and belongs to the technical field of preparation of medical intermediates. O-phenylenediamine is used as a raw material and reacts with ethyl formate, then dimethyl sulfate is adopted for a nitrogen-methylation reaction, finally formyl is removed under the action of acid, and N1, N2-dimethylbenzene-1, 2-diamine is obtained. According to the method, all the raw materials can be conveniently purchased on the market, the process of each step of reaction is simple and convenient, no expensive catalyst is used, the yield is high, and industrial production is easy.

The invention discloses a clean production process for cationic dyes. A parent substance and dimethyl sulfate undergo a methylation reaction, followed by expansion and hydrolysis. Salt and zinc chloride are added for transformation and crystallization. After crystallization, the product and mother liquor wastewater are filtered. Zinc chloride and sodium chloride are added to the mother liquor wastewater obtained after crystallization for neutralization. After nanofiltration, the concentrated solution is applied to the hydrolysis and expansion process of the next batch. The wastewater after nanofiltration enters a biochemical treatment system. The clean production process of the invention can solve the problems of generating and applying crystallization wastewater, reduce wastewater treatment costs, increase product yield, reduce wastewater generation and salt usage, and recover a small amount of cationic dye dissolved in the wastewater.

The present application relates to a kind of preparation methods of 4-acetamido-5-chloro-2-methoxybenzoic acid methyl ester, steps include: S1, m-amino phenol is reacted with acetic anhydride to generate m-acetylamino phenol;S2, the m-acetylamino phenol is reacted with carbon dioxide to generate 4-acetylamino salicylic acid;S3, the 4-acetylamino salicylic acid is reacted with dimethyl sulfate to generate 2-methoxy-4-acetylamino benzoic acid methyl ester;S4, the 2-methoxy-4-acetylamino benzoic acid methyl ester is reacted with hydrochloric acid to generate 4-acetamido-5-chloro-2-methoxybenzoic acid methyl ester.The preparation method of the present application not only improves product quality and production efficiency, but also reduces cost, simplifies operation, and is friendly to environment, with significant industrial application prospect and market competitiveness.

The invention provides a method for treating excessive halogen in an ionic photoacid generator, which comprises the following steps: adding a crude product of the ionic photoacid generator to be treated into a reactor, adding a solvent, stirring, then adding a sulfate reagent, reacting, then adding an anion raw material, continuing reacting, and after the reaction is completed, carrying out post-treatment to obtain the excessive halogen in the ionic photoacid generator. The ionic photoacid generator with qualified halogen content is obtained. The halogen content is less than or equal to 10 ppm. And the sulfate reagent is dimethyl sulfate, diethyl sulfate, dipropyl sulfate or dibutyl sulfate. The method for treating the residual halogen in the ionic photoacid generator is mild in reaction condition, simple in technological process, environment-friendly and high in yield, and can be widely applied to preparation of iodonium salt and sulfonium salt photoacid generators.

This invention discloses a continuous flow synthesis method for nitromethane. The method includes mixing dimethyl sulfate, nitrite, a catalyst, and water to obtain a mixture; continuously feeding the mixture into a first reactor and reacting it at a first temperature to obtain a first reaction solution; continuously feeding the first reaction solution into a second reactor and reacting it at a second temperature to obtain a second reaction solution; continuously feeding the second reaction solution into a distillation column to obtain crude nitromethane, which is then purified by distillation to obtain the final nitromethane product. Both the first and second reactors are plug flow reactors, and the first temperature is lower than the second temperature. This method provides milder reaction conditions, easier process control, and by refining and precisely controlling the reaction temperatures of the two stages, it reduces the generation of byproducts and energy costs, avoids the safety hazards caused by violent foaming and material surges during the reaction, and significantly improves both process safety and efficiency.

The invention relates to the technical field of pesticide preparation, and particularly discloses a green synthesis process of pyraclostrobin. According to the preparation method, N-hydroxy-N-2-[(N-p-chlorphenyl)-3-pyrazoloxymethyl] phenyl carbamate and N, N-dimethylformamide dimethyl acetal are taken as raw materials, an organic amine compound is taken as a catalyst, and pyraclostrobin is prepared through an etherification reaction. According to the invention, the low-toxicity N, N-dimethylformamide dimethyl acetal is adopted to replace a highly toxic reagent dimethyl sulfate, so that the safety and environmental protection property of the process are improved from the source; meanwhile, an organic amine substance is adopted as a catalyst, so that the etherification reaction is effectively promoted, the reaction is more sufficient, and the yield and the purity of the pyraclostrobin product are remarkably improved; and the etherification reaction process is mild, the energy consumption is greatly reduced, the energy consumption and the equipment loss are reduced, the wastewater generated by the process is low in toxicity and easy to treat, the wastewater treatment cost and the environmental risk are remarkably reduced, and the method has relatively high economic benefits and environmental benefits.

The invention relates to the technical field of detection of dimethyl sulfate, in particular to a gas chromatography-mass spectrometry detection method of dimethyl sulfate in soil and sediment, which at least comprises the following steps: (1) collecting a sample, and measuring moisture in the sample; (2) adding an extracting agent into the sample, and carrying out vortex oscillation, ultrasonic extraction and solid-liquid separation to obtain supernate; and (3) filtering the supernate through a needle filter into a chromatographic sampling bottle, testing by adopting a gas chromatograph-mass spectrometer, comparing the retention time, characteristic ions and abundance of the sample and the standard solution to determine whether the dimethyl sulfate exists in the sample, quantifying by adopting an external standard method, and calculating the content of the dimethyl sulfate in the sample through a formula. According to the method, matching of all steps in the method is optimized, interference caused by complex environment matrixes is effectively overcome, accurate detection of the dimethyl sulfate in the soil and the sediments is achieved, and the method is simple and easy to promote daily monitoring of the DMS in the soil and the sediments.

The invention discloses a gas chromatography-mass spectrometry detection method for dimethyl sulfate in solid waste. The gas chromatography-mass spectrometry detection method comprises the steps of sample collection and preservation, pretreatment (preparation, extraction, concentration, purification and internal standard addition) and instrumental analysis. By optimizing extraction conditions, a purification process and chromatographic mass spectrometry parameters, high-sensitivity and high-precision detection is realized, the detection limit is 0.47 mg / kg, the lower determination limit is 1.88 mg / kg, and the method is suitable for quantitative analysis of the substance in the solid waste.

The invention provides a preparation method of 4-methoxymethyl-N-phenyl-1-benzyl-4-piperidylamine dihydrochloride, which comprises the following steps: taking a compound (III) as an initial raw material, generating a compound (IV) under the action of a reducing agent, reacting the compound (IV) with dimethyl sulfate to generate a compound (V), and salifying the compound (V) with hydrogen chloride gas to generate a compound (VI). The synthesis method disclosed by the invention is mild in reaction condition, simple and convenient in post-treatment procedure, high in production efficiency, high in product purity and yield, low in industrial production cost and capable of realizing industrial production.

The invention relates to a synthesis method of an azoxystrobin intermediate, and belongs to the technical field of organic synthesis.The synthesis method comprises the steps that benzofuranone serves as a raw material and is directly condensed with formate under the action of alkali, then dimethyl sulfate is methylated, and 3-(alpha-methoxyl) methylene benzofuranone is obtained. The use of expensive trimethyl orthoformate is avoided, and the cheap and easily available formate is adopted, so that the raw material cost of the azoxystrobin intermediate is greatly reduced, and the method is simple in process route, high in yield and suitable for industrial production.