33 results about "Dimethyl acetal" patented technology

The invention relates to a bis (2, 2-methylene disulfide) episulfide compound with an ultrahigh refractive index and a preparation method thereof, and belongs to the technical field of optical materials, and the preparation method comprises the following preparation steps: taking chloroacetaldehyde dimethyl acetal, a solvent, disulfur dichloride and an acidifying agent, and carrying out a sulfuration substitution reaction to prepare 2-chloro-1, 2-dithiol; the preparation method comprises the following steps: carrying out nucleophilic substitution reaction on methoxycarbonyl sulfonyl chloride, a low-boiling-point solvent and 2-chloro-1, 2-ethanedithiol, and dropwise adding a bicarbonate saturated aqueous solution to carry out cyclization reaction so as to prepare a methoxycarbonyl disulfide-episulfide compound; and adding dimercaptomercaptan, and reacting to obtain a product. The process route provided by the invention solves the problems of tedious step-by-step reaction, more byproducts and high cost in the prior art.

The invention provides a solid polyamine adsorption material and a preparation method thereof, and belongs to the field of adsorption materials. Comprising the following steps: carrying out selective protection reaction on polyamine and N, N-dimethylformamide dimethyl acetal in an organic solvent, so that part of active sites of the polyamine form a polyamine protecting group, and obtaining imidazoline polyamine; the preparation method comprises the following steps: carrying out a grafting reaction on imidazoline polyamine and Merrifield resin in an organic solvent, and filtering and purifying a mixed solution after the grafting reaction to obtain grafted resin spheres; and carrying out a hydrolysis reaction on the grafted resin balls and a strong alkali solution to hydrolyze and activate the polyamine protecting group, and then filtering and purifying the hydrolyzed and activated mixed solution to obtain the solid polyamine adsorption material. Compared with direct grafting of polyamine, part of active sites are protected through imidazoline of the polyamine, additional consumption of the active sites during direct grafting of the polyamine chain is avoided, and the grafting rate of the polyamine chain is high.

The invention discloses a method for oxidative depolymerization of a beta-O-4 lignin model compound based on an electrochemical continuous flow reactor, the reactor comprises an anode plate, a cathode plate and a snakelike reaction channel located between the anode plate and the cathode plate, and the anode plate and the cathode plate are respectively connected with an anode and a cathode of a power supply; the method comprises the following steps: dissolving a beta-O-4 lignin model compound and tetraethylammonium perchlorate in a mixed solvent of acetonitrile and methanol to obtain a homogeneous solution, continuously introducing the homogeneous solution into a snakelike reaction channel of a reactor, and applying current to carry out an electrolytic reaction to prepare an aromatic compound; continuous depolymerization of the beta-O-4 lignin model compound can be achieved, products can be discharged in time, over-reaction can be relieved, enlargement is easy, meanwhile, due to the narrow gap and the large specific surface area of the reactor, the electrolyte concentration and the electrolytic tank pressure can be remarkably reduced, single-time conversion is achieved, the reaction rate is remarkably increased, the products are mainly benzaldehyde dimethyl acetal, and the cost is low. And the conversion rate and the yield are relatively high.

The invention discloses a preparation process of a swimsuit fabric, belonging to the field of textile technology, and comprising a weaving process and a sunscreen treatment process. The invention adopts an emulsion interfacial polymerization method to transfer CeO2 particles into polyurethane shell microcapsules, thereby preparing microcapsules with anti-ultraviolet function; ultrasonic treatment is performed to allow fiber pores of the swimsuit fabric to accommodate the formed sol-gel, and the swimsuit fabric is filled with the sol-gel through ultrasonic penetration; formaldehyde is used to cause an acetalization reaction of the gel film layer under sulfuric acid, and acrylic acid is polymerized with acrolein dimethyl acetal during curing to form a dense cured film layer, thereby protecting CeO2 particles in the pores between fibers and providing a hydrophobic interface, preventing the swimsuit fabric from increasing light transmittance due to water adhesion, thereby improving the anti-ultraviolet performance; and the cured film layer protects the CeO2 particles so that they can still exist after multiple washings, thereby improving the durability of the anti-ultraviolet performance.

This invention discloses a highly efficient method for synthesizing proxalutamide intermediates, belonging to the field of pharmaceutical synthesis technology. First, dimethyl malonate and 2-chloro-5-nitropyridine are used as raw materials, condensed in the presence of potassium carbonate to generate dimethyl 2-(5-nitropyridine-2-yl)malonate. This is then reacted with tert-butyl acrylate and acid-hydrolyzed to obtain 4-(5-nitropyridine-2-yl)butyric acid. After activation with N,N'-carbonyl diimidazole, it is coupled with aminoacetaldehyde dimethyl acetal to form N-(2,2-dimethoxyethyl)-4-(5-nitropyridine-2-yl)butyramide. Then, a cyclization reaction mediated by phosphorus pentoxide and methanesulfonic acid is used to generate crude 2-(3-(5-nitropyridine-2-yl)propyl)oxazole. After purification, the nitro group is reduced by catalytic hydrogenation, and finally, it reacts with 1,5-naphthalenedisulfonic acid to form a salt, yielding the proxalutamide intermediate. This method achieves highly efficient synthesis of proxalutamide intermediates.

The application discloses a preparation method of 1,1,4,4-tetramethoxy-2-butene and application thereof, and belongs to the field of organic chemical synthesis. The method comprises the following steps: chloroacetaldehyde dimethyl acetal and triphenylphosphine are reacted to generate acetaldehyde dimethyl acetal phosphonium salt; and the acetaldehyde dimethyl acetal phosphonium salt is reacted with glyoxal monoacetal to generate 1,1,4,4-tetramethoxy-2-butene. The method is high in efficiency, environmental protection, simple in operation and friendly to the environment.

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 synthesis of compounds, in particular to a synthesis method of 2, 4-dihydroxy-5-cyanopyrimidine, which specifically comprises the following steps: S1, mixing N-cyano acetyl urethane and N, N-dimethylformamide dimethyl acetal according to a mass ratio of 1: (0.8-1) in a solvent at the temperature of 10-30 DEG C, and adding the mixture into a reaction kettle to obtain a primary mixed solution; s2, stirring the primary mixed solution, heating to 60-70 DEG C, keeping the temperature, and reacting for 2-4 hours until the raw materials are completely converted, so as to obtain a secondary mixed solution; s3, reducing the temperature of the mixed solution obtained in the step S2 to 0-10 DEG C, dropwise adding stronger ammonia water within 1-2 hours, heating to 60-70 DEG C, and keeping the temperature for 1-2 hours; and S4, cooling the solution obtained in the step S3 to 0-10 DEG C again, dropwise adding concentrated hydrochloric acid, adjusting the pH value to 1-2, keeping the temperature for 1-2 hours, filtering, washing and drying to finally obtain the 2, 4-dihydroxy-5-cyanopyrimidine. According to the method, the yield is increased to 92-95%, the purity is stabilized at 99.5% or above, the usage amount of an organic solvent and waste discharge are reduced, and the method conforms to the green chemistry concept.

The invention belongs to the field of biomass molecule high-valued conversion, and discloses a method for high-valued conversion of a levulinic acid derivative, in particular to a method for converting the levulinic acid derivative into an organic synthesis building block, which aims at the levulinic acid derivative 4, 5-dihydro-6-methylpyridazine-3 (2H)-ketone, and converting glyoxal dimethyl acetal and 4, 5-dihydro-6-methylpyridazine-3 (2H)-ketone into an organic synthesis building block. The preparation method comprises the following steps: carrying out condensation reaction on 2, 5-dihydro-6-methylpyridazine-3 (2H)-ketone in a solvent under an alkaline condition to obtain a target acetal synthesis building block; the structural formula of the building block is shown as a formula B-1. According to the synthetic method disclosed by the invention, a synthetic route is designed, a levulinic acid derivative, namely 4, 5-dihydro-6-methylpyridazine-3 (2H)-ketone, is converted into a universal organic synthetic building block (as shown in a formula B-1), and high-value chemicals including quinoline compounds and sitroxazine can be synthesized by utilizing the synthetic building block.

The present application relates to the technical field of chemical material production, and particularly relates to a preparation method of N-(2,2-dimethoxyethyl)-1H-imidazole-1-formamide (183660-46-0); clean dichloromethane is added into a clean reaction kettle; the temperature of the reaction kettle is reduced to -5-5 DEG C, N,N'-carbonyldiimidazole is added; aminoacetaldehyde dimethyl acetal is added dropwise, and reaction is carried out for 2h; the temperature of the reaction kettle is increased, and stirring is continuously carried out at 18-25 DEG C for 12-16h, so that white suspension is obtained; normal heptane is slowly added dropwise at 18-25 DEG C, the dropwise adding time is 1-2h, stirring is continuously carried out at 18-25 DEG C for 2h, filtration is carried out under the protection of nitrogen, and the filter cake is washed once with a mixed solution of dichloromethane and normal heptane; dichloromethane and crude N-(2,2-dimethoxyethyl)-1H-imidazole-1-formamide are added, stirring is carried out at 20-25 DEG C for 30min, normal heptane is slowly added and stirred for 1h, the filter cake is collected, and drying is carried out; the fine operation of the product processing process is realized, the generation of by-products is effectively reduced, impurity wrapping and raw material residue are avoided, and the purity of the target product is improved.

The invention belongs to the field of organic synthesis, and discloses a method for preparing an indole-dipyrromethene derivative, which comprises the following steps: firstly, carrying out Ugi reaction on glyoxal dimethyl acetal, isonitrile, trifluoroacetic acid and amine to obtain an alpha-acylamino amide compound; and then under the action of an acid catalyst, carrying out [3 + 2] cyclization aromatization on the indole-dipyrromethene derivative, 4-methoxy ethyl acetoacetate and an indole derivative to obtain the indole-dipyrromethene derivative. According to the method, the indole-dipyrromethene derivative is prepared from the Ugi adduct prepared through the Ugi reaction in which glyoxal dimethyl acetal participates through [3 + 2] cyclization aromatization with ethyl 4-methoxyacetoacetate and the indole derivative, precious metal is not used in the overall reaction, the final target product can be obtained through a one-pot two-step method, and the step operation is simple. In addition, no additional ligand or additive needs to be added, and the method has the advantages of being good in reaction selectivity, high in yield, easy in product separation and the like.

The invention discloses a production process of aminoacetaldehyde dimethyl acetal, and relates to the field of organic chemical synthesis, and the production process comprises the following steps: (1) ammonification reaction: firstly mixing ammonia water and strong base to form a mixed system, adding a phase transfer catalyst into the mixed system, heating to a preset reaction temperature, slowly dropwise adding chloroacetaldehyde dimethyl acetal, and reacting for 1-2 hours at the temperature of 30-60 DEG C; according to the invention, the phase transfer catalyst is introduced as an acid-binding agent and an accelerant, the reaction temperature is controlled at 30-100 DEG C, and the whole process can be carried out at normal pressure or near normal pressure, so that the dependence of the existing process on high temperature and high pressure is thoroughly abandoned; due to the mild reaction conditions, the requirements for pressure resistance and high temperature resistance of equipment are greatly reduced, the equipment investment and the daily maintenance cost are reduced, and meanwhile, the safety risk in a high-pressure environment is avoided; on the other hand, energy consumption in the production process is remarkably reduced through the low-temperature reaction, the low-carbon chemical development trend is met, and the production cost is reduced for enterprises.

This invention relates to a method for synthesizing 1-cyclopropyl-4-oxo-7-fluoro-8-methoxy-1,4-dihydroquinoline-3-carboxylic acid, a key intermediate for numonoxacin. The method uses 2,4-difluoro-3-methoxyacetophenone as a starting material and proceeds through four steps: haloform reaction, acyl chloride formation and Maxwell's acid condensation, reaction with dimethylformamide dimethyl acetal and cyclopropylamine, and base-catalyzed cyclization and acid deprotection. This efficient method yields the target intermediate. The synthetic route of this invention utilizes readily available raw materials, mild reaction conditions, and simple operation. The multi-step reaction can be carried out in a one-pot process, achieving a total conversion rate of approximately 85% and a product purity exceeding 99.5%, making it suitable for industrial production.

The invention relates to the technical field of perfumes, in particular to an efficient condensation process in perfume synthesis, which comprises the following steps: adding styrene oxide into a methylation reagent, and reacting under the catalysis of acid; after the reaction is finished, adding an alkaline solution to adjust the pH value to 7-8, standing for layering, and taking an organic phase; and evaporating the organic phase at 50-70 DEG C to remove the solvent, and rectifying to obtain the phenylacetaldehyde dimethyl acetal. The high-efficiency condensation process in the synthesis of the perfume-phenylacetaldehyde dimethyl acetal provided by the invention has the advantages of low cost, simple process procedure, low production energy consumption, high yield, total yield of 93% or more, good product quality, purity of 98.5% or more, and wide industrial application prospect.

The utility model discloses an autoclave sampling device for aminoacetaldehyde dimethyl acetal production, which belongs to the technical field of autoclave sampling and comprises a supporting unit, a sliding unit, a driving unit and a sampling unit. An inlet is formed in the upper surface of the fixing block, the sliding unit comprises a sliding groove formed in the top of the fixing barrel, a T-shaped sliding block sliding in the sliding groove in a lifting mode and a telescopic rod vertically and fixedly connected with the top of the T-shaped sliding block, and the driving unit comprises an air cylinder arranged at the top of the supporting frame. A driving rod is arranged at the bottom of the air cylinder, a top block is fixedly connected with the bottom of the driving rod, and the side surface of the top block is fixedly connected with the side wall of the telescopic rod. The sampling device has the advantages that the sampling work can be carried out by adjusting the atmospheric pressure through the sampling unit, the internal pressure of the kettle body is not required to be matched for use, and the operation and the sampling are convenient.

The invention relates to a synthesis method of 1H-pyrrolo [3, 2-B] pyridine-6-amine. Comprising the following steps: carrying out a reaction on 5-bromo-2-methyl-3-nitropyridine and N, N-dimethyl formamide dimethyl acetal to obtain (E)-2-(5-bromo-3-nitropyridine-2-yl)-N, N-dimethyl ethylene-1-amine, and carrying out a reaction on the (E)-2-(5-bromo-3-nitropyridine-2-yl)-N, N-dimethyl ethylene-1-amine and the N, N-dimethyl formamide dimethyl acetal to obtain the 5-bromo-2-methyl-3-nitropyridine. Adding the 6-bromine-4-azaindole into acetic acid, and performing reduction and cyclization reaction by using an iron-based catalyst to obtain 6-bromine-4-azaindole; and then adding into ammonia water, and reacting under a copper-based catalyst to obtain the 1H-pyrrolo [3, 2-B] pyridine-6-amine. The 1H-pyrrolo [3, 2-B] pyridine-6-amine is effectively obtained through three-step synthesis. A compound of Fe-coated PMMA-b-PDMAEMA and PE wax coated iron powder is used as an iron-based catalyst, and the ratio of the Fe-coated PMMA-b-PDMAEMA to the PE wax coated iron powder is reasonably adjusted, so that the catalytic effect of the reduction and cyclization reaction is remarkably improved and further optimized, and the conversion rate is improved, thereby realizing high yield of the product.

The invention belongs to the technical field of medicine synthesis, and provides a synthesis method of a medical intermediate 7-hydroxyfuro [3, 2-b] pyridine and an intermediate compound thereof. The preparation method comprises the following steps: taking maltol as a raw material, carrying out hydroxyl protection to obtain a compound shown in a formula II, reacting with N, N-dimethylformamide dimethyl acetal to obtain a compound shown in a formula III, reacting with alcohol under an acidic condition to obtain a compound shown in a formula IV, reacting with ammonia water to obtain a compound shown in a formula V, and carrying out dehydroxylation protection to obtain a compound shown in a formula VI. And performing dealcoholization and cyclization under an acidic condition to obtain the target compound 7-hydroxyfuro [3, 2-b] pyridine. The method has the advantages of simple synthesis steps, convenient process, simple and easily available raw materials, low cost, convenient operation method and high overall yield, and is suitable for industrial large-scale production. The intermediate compounds shown in the formula IV and the formula V and tautomers of the intermediate compounds can be used for preparing 7-chloro-6-nitrofuro [3, 2-b] pyridine as a key starting material of a JAK1 / TYK2 dual inhibitor.

The application provides a method for synthesizing an alpha, beta-unsaturated aldehyde compound by using copper as a catalyst, using an alkyne as a reaction raw material, using silane as a hydrogen source, using N, N-dimethylformamide dimethyl acetal as a formyl source, and using a carbene copper as a catalyst to efficiently synthesize the alpha, beta-unsaturated aldehyde compound. The method avoids the use of flammable and explosive and toxic synthesis gas, the raw material is cheap and easy to obtain, the reaction condition is mild, the operation is simple, the substrate has a wide application range, and excellent stereoselectivity and regioselectivity are obtained. The product alpha, beta-unsaturated aldehyde compound is an important intermediate for synthesizing complex molecules such as drugs and natural products, and the method has important significance in the fields of medicines, pesticides and fine chemicals.

The invention belongs to the field of organic matter preparation, and particularly relates to a method for purifying N, N-dimethylformamide dimethyl acetal, which comprises the following steps: amidating an amino-containing silane coupling agent by using low-molecular-weight organic acid to prepare an amide group-containing silane coupling agent; the preparation method comprises the following steps: modifying nano silicon dioxide by adopting a silane coupling agent containing an amide group to obtain modified silicon dioxide; mixing the modified silicon dioxide with a polymer, and combining with a membrane matrix to obtain a filter membrane; the method comprises the following steps: removing substances with a boiling point of below 80 DEG C in a filtrate obtained after synthesis of N, N-dimethylformamide dimethyl acetal, completing primary purification, and then continuously purifying the N, N-dimethylformamide dimethyl acetal obtained by primary purification by using a filter membrane. The method provided by the invention realizes low energy consumption, low cost and high efficiency purification of N, N-dimethylformamide dimethyl acetal.

The application provides a preparation method of roxadustat, and the roxadustat (compound 1) is prepared from 4-hydroxy-7-phenoxyisoquinoline-3-carboxylic acid methyl ester (compound 2) through condensation reaction with N,N-dimethylformamide dimethyl acetal, reduction reaction and ammonolysis reaction. The synthesis method has the advantages of short steps, low cost, safety, environmental protection, simple operation and industrialization value. The roxadustat prepared by the method has good quality, and can be used for preparing roxadustat preparations for clinical use.

The invention relates to a method for separating alcohol mixtures with high water content using an extraction solvent. In particular, the present invention relates to a process for liquid-liquid extraction of a C2-C3 alcohol or a mixture of C2-C4 alcohols from a C2-C3 alcohol or a mixture of C2-C4 alcohols and water with an extraction solvent selected from the group consisting of isobutyraldehyde and n-pentane / dimethylacetal mixtures.

The utility model relates to a production line for biphenyl amylene fine chemicals. An intermediate propyl cyclohexyl biphenyl formaldehyde production line, an intermediate propyl cyclohexyl biphenyl acrolein dimethyl acetal production line, a propyl cyclohexyl biphenyl propionaldehyde dimethyl acetal toluene solution production line, a propyl cyclohexyl biphenyl propionaldehyde toluene solution production line and a propyl cyclohexyl biphenyl pentene cis-trans mixture production line are adopted; the trans-propyl cyclohexyl biphenyl pentene production line and the trans-propyl cyclohexyl biphenyl pentene finished product production line are sequentially connected, and finally the trans-propyl cyclohexyl biphenyl pentene finished product is prepared through concentration of the multi-stage reaction kettle, crystallization of the crystallization kettle, filter pressing of the filter press and drying of the dryer. The production line has the functions of high efficiency and recycling, has better cost control and production efficiency, and is suitable for industrial mass production.

The invention discloses a synthesis method of 4-(diacetoxyphosphoryl)-2-methyl-2-ethyl crotonate and application of the 4-(diacetoxyphosphoryl)-2-methyl-2-ethyl crotonate, and relates to the technical field of fine chemical engineering. The synthesis method comprises the following steps: carrying out condensation reaction on halogenated acetaldehyde dimethyl acetal and ethyl propionate to form a first compound; removing methanol from the first compound to form a second compound; and carrying out a reaction on the second compound and triethyl phosphite to obtain the ethyl 4-(diacetoxyphosphoryl)-2-methyl-2-butenoate. According to the present invention, the new 4-(diacetoxyphosphoryl)-2-methyl-2-ethyl crotonate synthesis route is provided, the halogenated acetaldehyde dimethyl acetal is adopted as the starting material, the synthesis route is simple, the raw material is simple and easy to obtain, the 4-(diacetoxyphosphoryl)-2-methyl-2-ethyl crotonate yield is high, and the product yield can achieve more than 88%.

The utility model discloses an aminoacetaldehyde dimethyl acetal moisture detection liquid return prevention moisture titration device, which belongs to the technical field of titration devices, and comprises a detection unit, a driving unit and a pressure intensity adjusting unit, the detection unit comprises a machine body, a detection mechanism arranged on the upper surface of the machine body, and a bottle body positioned on the detection mechanism; the supporting plate is installed on the machine body, the stand column is vertically arranged on the supporting plate, the air cylinder is located in the stand column and extends upwards, the adjusting plate is installed at the top of the extending end of the air cylinder, and a connecting rod is arranged at the bottom, away from the side of the air cylinder, of the adjusting plate. The bottom of the connecting rod is in threaded connection with a threaded rod; the pressure intensity adjusting unit comprises a cover body installed on the bottle body and a sealing block connected with the top of the cover body, and a movable groove is formed in the top of the sealing block. The pressure intensity adjusting device has the advantages that internal pressure intensity and external pressure intensity can be conveniently adjusted to a certain extent, and the liquid return condition is reduced.

The present invention provides a method for preparing high-purity vinyl methyl ether by gas-phase cracking of acetaldehyde dimethyl acetal, and relates to the technical field of preparation of vinyl methyl ether. The present invention adopts a solid inorganic acid catalyst for cracking reaction, and the catalyst is prepared by a mixing method. The cracking reaction is carried out in a fixed bed reactor. After being gasified and preheated, acetaldehyde dimethyl acetal passes through the reaction bed and, under the action of the catalyst, is cracked into vinyl methyl ether and methanol gas. Vinyl methyl ether with higher purity is obtained by step-by-step cooling and separation. The catalyst preparation process of the present invention is simple, low in cost, high in catalytic activity, strong in selectivity, and has few cracking product components. It also has good preparation process stability, mild reaction conditions, can be continuously produced and operated for a long period of time, has simple equipment, low investment, high product purity, less three wastes, and high energy efficiency, and has good application prospects.

The invention relates to a preparation method of 3-fluoro-1, 3-propane sultone, and belongs to the technical field of preparation of battery electrolyte additives, and the preparation method comprises the following steps: S1, dissolving a sulfonating reagent in water, adding an initiator and acrolein dimethyl acetal, heating to 40-100 DEG C, and reacting for 2-10 hours to generate an intermediate 3, 3-dimethoxy propyl sulfonic acid; s2, cooling, adjusting to acidity, spin-drying a water phase, extracting, carrying out suction filtration, and spin-drying a solvent to obtain 3-formyl propyl sulfonic acid; s3, the temperature is increased to 50 DEG C to 200 DEG C, and 3-hydroxy-1, 3-propane sultone is obtained through cyclization; and S4, carrying out a fluorination reaction on the 3-hydroxy-1, 3-propane sultone and a fluorination reagent, removing the solvent after the reaction is completed to obtain a crude product, and carrying out recrystallization purification to obtain the product 3-fluoro-1, 3-propane sultone. The preparation method disclosed by the invention is simple to operate, and the obtained 3-fluoro-1, 3-propane sultone is high in purity and high in yield.

The invention belongs to the technical field of chemical synthesis, and particularly relates to a preparation method of a fenerenone intermediate 4-cyano-2-methoxybenzaldehyde. The method comprises the following steps: adding 3-methoxy-4-methylbenzonitrile into chlorobenzene, adding N, N-dimethylformamide dimethyl acetal while stirring, carrying out a heating reaction, after the reaction is finished, carrying out vacuum concentration to remove the chlorobenzene, adding an organic solvent and water, adding sodium periodate at a controlled temperature, after the heat preservation reaction is finished, carrying out centrifugal filtration to remove sodium iodate, and separating the filtrate to obtain the 3-methoxy-4-methylbenzonitrile. And concentrating and drying an organic phase, adding a saturated alkane solvent, and crystallizing to obtain the 4-cyano-2-methoxybenzaldehyde. The method has the advantages of simple synthetic route, convenience in operation, low cost, small amount of three wastes, environment friendliness, recyclable solvent and high product purity, and is more suitable for industrial mass production.

This invention belongs to the field of catalyst technology, specifically relating to the application of amino-functionalized rare earth cluster-based MOFs as catalysts in the catalytic deacetalization-Knoevenagel condensation reaction. The application method is as follows: Activated amino-functionalized rare earth cluster-based MOFs material Yb-BPDC-(NH2)2 or Dy-BPDC-(NH2)2 is placed in a reaction tube, followed by the sequential addition of the reaction substrates benzaldehyde dimethyl acetal and malononitrile. Acetonitrile is used as the solvent medium, and deionized water is added as a reaction promoter. Under continuous mechanical stirring and nitrogen protection, the reaction mixture is placed in an 80°C constant temperature oil bath for 12 hours. The amino-functionalized rare earth cluster-based MOFs material prepared by this invention exhibits excellent catalytic performance and can efficiently catalyze the deacetalization-Knoevenagel condensation reaction.

The application provides a preparation method of a compound 5,6-dihydroxyindole, which comprises the following steps: taking phenolic hydroxyl-protected 4-methyl-5-nitro-o-benzoquinone as raw material, reacting with N,N-dimethylformamide dimethyl acetal and a secondary amine to obtain compound IV, then performing a reduction ring closure reaction to obtain compound V, and removing a phenolic hydroxyl protection group to obtain 5,6-dihydroxyindole. The method is a brand-new process route, the raw material is cheap and easy to obtain, the reaction yield is high, the side reaction is less, and the method is suitable for industrial production. In addition, the method has the advantages of less operation steps, short reaction flow, simple reaction post-treatment, and high product purity.

The invention belongs to the field of chemical drug synthesis, and particularly relates to a preparation method of an antibacterial drug sitafloxacin intermediate. The preparation method comprises the following steps: carrying out condensation reaction on a compound I and N, N-dimethylformamide dimethyl acetal to prepare an intermediate IV; the intermediate IV and (1R, 2S)-1-amino-2-fluorocyclopropane are subjected to a substitution reaction, and an antibacterial drug sitafloxacin intermediate compound III is prepared. The preparation method disclosed by the invention has the advantages of mild reaction conditions, short reaction time, small and single solvent dosage, high reaction conversion rate and high selectivity, and meets the requirements of industrial large-scale production.