47results about How to "Sources are cheap and readily available" patented technology

The present invention discloses a kind of catalyst for water vapor reformation of ethanol to prepare hydrogen and its preparation process and use. The catalyst includes composite carrier of alumina and magnesia and at least one of carried transition metal, transition metal alloy, and transition metal-RE metal mixed oxide. The preparation process includes the following steps: preparing catalyst carrier, compounding water solution of nitrate, setting the carrier into the water solution of nitrate and adding urea via stirring, evaporating to eliminate water, stoving, grinding and roasting. The catalyst has low carrier cost and simple preparation process, is used in water vapor reformation of ethanol to prepare hydrogen, and can result in low reaction temperature, high hydrogen selectivity and no generation of side products ethylene, acetaldehyde, etc.

The invention discloses near-full-spectrum fluorescent nanocarbon dots and a preparation method thereof and belongs to the field of carbon nano-luminescence materials. The wavelength of an emission peak of the carbon point synthesized by the method is 470nm-700nm; the fluorescent emission peak of the carbon point almost has no change along with the change of the emission wavelength; the carbon dots have the characteristics of high fluorescence intensity and stable quantum yield. The synthesis and preparation method comprises the following steps: adding carboxyl-containing organic acid and organic amine into a certain amount of deionized water according to a mole ratio of (1 to 1)-(1 to 0), uniformly stirring and then transferring the deionized water to a hydrothermal reactor, carrying out hydrothermal reaction, then naturally cooling the hydrothermal reactor to room temperature and preparing a carbon dot aqueous solution. According to the near-full-spectrum fluorescent nanocarbon dots and the preparation method of the carbon dots, the raw materials used for synthesizing the carbon dot are wide in sources and low in cost, and are easily available and almost non-toxic; the carbon dot synthesizing period is short; the carbon dot synthesizing equipment is simple.

The invention provides a method for synthesizing difluprednate from a sterol fermentation product. The sterol fermentation product, namely 9 Alpha-hydroxyl-androstane-1,4-diene-3,17-diketone (9 Alpha-OH-AD) obtained by fermenting phytosterol of which the content in byproducts of the grease industry is very high, serves as a starting raw material. The method comprises the following 15 reaction steps in total: dehydrating steride 9-hydroxyl to form a double-bond; adding 17-carbonyl with acetylene; dehydrating; producing 21-copper carbonyl under an acid condition; epoxidizing 16,17-double bond; oxidizing periodide and introducing 21-hydroxyl; performing ring opening on 16,17 Alpha-epoxy hydrobromate; hydrogenating for removing 16 Beta bromine; forming a ring on orthoester; performing ring opening; esterifying; epoxidizing 9,11-double bond-Beta; enolizing and esterifying; performing ring opening on 6-electrophilic fluoro; and performing ring opening on 9,11-epoxy fluoro. According to the method, steride 17 Alpha and 21-dyhydroxyl are efficiently built by means of periodide oxidization, epoxide ring-opening and debromination and an important intermediate type 11 compound is obtained; in the whole process, a large quantity of heavy metal pollutant chromium which is generated when producing corticoid medicines in the traditional industry is effectively avoided, so that the method is green, environment-friendly and suitable to industrialized production.

The invention belongs to the technical field of medicines and particularly relates to a preparation method of cefditoren pivoxil. The preparation method particularly includes following steps: (1) carrying out a reaction between cefditoren mother nucleus 7ATCA and AE-activated ester with dichloromethane as a solvent under an alkaline condition at 0-5 DEG C; (2) performing extraction with pure water and adding a sodium iso-octoate / acetone solution to obtain cefditoren sodium; (3) carrying out a reaction between the cefditoren sodium and iodomethyl pivalate under the alkaline condition at -40 DEG C to obtain a cefditoren pivoxil solution; (4) adding pure water to separate out a crystal to obtain a crude product of the cefditoren pivoxil. The technical scheme also comprises steps of dissolving the crude product of the cefditoren pivoxil in a mixed solution including dichloromethane and anhydrous ethanol, washing the material solution with a 1% sodium bicarbonate solution and pure water, collecting an organic phase, and performing a pressure-reducing evaporate-drying process to obtain the cefditoren pivoxil being higher than 99% in purity and less in impurities. The preparation method is simple in operation, is easy to control, is high in yield, allows the raw material to be obtained easily and is suitable for industrialized large-scale production.

The invention relates to a tumor-targeted multifunctional nano probe with MRI (Magnetic Resonance Imaging) / SPECT (Single Photon Emission Computed Tomography) bimodal images as well as a preparation method and application thereof. The nano probe comprises an MNPs-DSPE-PEG-RGD nano probe composed of Fe@Fe3O4 nano particles and liposome DSPE-PEG-RGD and liposome DSPE-PEG which are coupled on the surface layer of the Fe@Fe3O4 nano particles, and radionuclide I125 can also be marked on the MNPs-DSPE-PEG-RGD nano probe to form an MNPs-DSPE-PEG-RGD-I125 nano probe. The preparation method comprises the following steps: dissolving DSPE-PEG-RGD and DSPE-PEG in an organic solvent, adding an Fe@Fe3O4 nano particle solution, and mixing uniformly to obtain the MNPs-DSPE-PEG-RGD nano probe; and marking with I125 by a chloramine-T method to obtain the MNPs-DSPE-PEG-RGD-I125 nano probe. The prepared MNPs-DSPE-PEG-RGD nano probe is used for MRI of human brain glioma, and the prepared MNPs-DSPE-PEG-RGD-I125 nano probe is used for SPECT. Compared with the prior art, the probe provided by the invention has the advantages of strong targeting property and the like, and multiple molecular imaging probes can be achieved on the same molecule.

The invention discloses a novel synthesis method of (R)-9-(2-phosphorylmethoxypropyl)adenyl-di(isopropoxycarbonylmethyl)ester, which comprises the following steps; after tenofovir used as a raw material and triethylamine are salified in acetonitrile, evaporating to remove acetonitrile, remaining triethylamine and water in the tenofovir triethylamine salt, and carrying out condensation reaction with chloromethylisopropyl carbonate to obtain the (R)-9-(2-phosphorylmethoxypropyl)adenyl-di(isopropoxycarbonylmethyl)ester. The method disclosed by the invention has the advantages of cheap and accessible raw material, easily controlled technological operation, high yield and low cost, and is suitable for industrial production.

The invention discloses a method for synthesizing a 1, 4-diene-6-methylene steroid as formula (I) and an intermediate. The method comprises the following steps: substituting the first position and the third position or only the third position of a 1, 4-diene-androstane compound as a raw material by pyrrolidine to generate 5, 6-ethylenic linkage compound; and introducing 6-methylene to the compound through Mannich reaction and elimination reaction to obtain the compound in the formula (I). Particular reaction formulas are shown as the above, and the method has the advantages of cheap and easily obtained raw materials, easily controlled process operation, high yield and low cost, and is suitable for industrialized production.

The invention relates to a novel method for synthesizing oxiracetam key intermediate ethyl 2-(2, 4-dioxopyrrolidine-1-yl) acetate. The method comprises the following step: by taking 4-halogenated acetoacetic ester and glycine ethyl ester hydrochloride as raw materials, under the effect of alkali, condensing in an organic solvent to obtain ethyl 2-(2, 4-dioxopyrrolidine-1-yl) acetate. The 4-halogenated acetoacetic ester and the glycine ethyl ester hydrochloride are taken as the raw materials and reacted in the organic solvent in the existence of the alkali in one step to obtain the target product; the 4-halogenated acetoacetic ester and the glycine ethyl ester hydrochloride are common merchant materials, convenient in source, cheap and easy to obtain, the reaction step is short, the operation is simple, the yield is high, the product purity is high, the product structure is authenticated, the after treatment is convenient, the three wastes are few and the method has good industrial application prospect.

The invention relates to a preparation method of a red mud-based catalyst for biomass pyrolysis, which comprises the following steps of: (1) grinding red mud and alkali together to obtain uniformly mixed solid particles; (2) carrying out high-temperature roasting, crushing, water adding, magnetic stirring and vacuum filtration on the solid particles obtained in the step (1) to remove Fe elements in the solid particles, so as to obtain a solution only containing Si and Al; and (3) carrying out baking and vacuum filtration on the Si and Al solution obtained in the step (2) to obtain the solid red mud-based catalyst. By the adoption of the method, solid waste generated in the aluminum industry can be effectively utilized, the high-quality catalyst can be prepared and applied to biomass pyrolysis, biomass resources are fully utilized, and high-quality oil and gas resources are generated.

The invention provides a cleaning effervescent tablet for fruits and vegetables, belonging to the technical field of cleaning of fruits and vegetables. The cleaning effervescent tablet is safe to useand capable of efficiently removing pesticide residues. The cleaning effervescent tablet adopts NaCl and starch as active ingredients and sodium carbonate, citric acid and talcum powder as auxiliary materials, and has the advantage that the components are natural, non-toxic, widely available and low in cost. The novel cleaning effervescent tablet for fruits and vegetables can quickly and effectively remove pesticide residues on the surfaces of fruits and vegetables and protect human health.

The invention provides a preparation method and denitration application of bimetal MOF-74(Co-Cu) with a meso-scale regulation and control multi-level core-shell structure. According to the catalyst, cobalt-containing long-chain organic molecular salt is selected to be efficiently coordinated with an organic ligand, special surface treatment is conducted on the cobalt-containing long-chain organic molecular salt and the organic ligand, then synthesis modification is conducted in a low-temperature steam environment through crystals, and Cu metal nanometer modified by a surface active agent grows on the surface of a Co precursor to form a multi-level core-shell structure composite material with different thicknesses. The prepared catalyst has the advantages of large specific surface area, good dispersibility and high selectivity. The prepared catalyst has excellent low-temperature catalytic denitration activity, and the conversion rate of nitric oxide reaches 96% or above within an operation window of 200-275 DEG C.

The invention provides a method for preparing a novel steroid aldosterone acceptor antagonist eplerenone. The method comprises the following steps: producing 9alpha-hydroxyandrostenedione (9alpha-OH-AD) through carrying out microbial conversion on a raw material androstenedione (4-AD), carrying out 17-keto epoxidation, condensation and carboxyl removal, introducing double bonds to 9(11) and 6(7), and carrying out 6(7) furanization, oxidation and esterification, and carrying out 9, 11 double bond epoxidation to generate eplerenone. The method which utilizes the cheap and easily available raw material and adopts a semisynthetic technology of microbial fermentation has the advantages of environmental protection, easy control of the operation, high yield, and low cost, and is suitable for industrialized production.

The invention discloses a preparation method of a silicon dioxide / cellulose composite porous material. The method comprises the following steps: simultaneously dissolving silicon dioxide and celluloseby a one-step technology by using an alkali / urine solution as a solvent, and forming silicon dioxide particles on the cellulose surface in situ to prepare the silicon dioxide / cellulose composite porous material. The method is simple to operate and short in process. In addition, the related raw materials are wide in source, are all solid wastes, and are cheap and easy to obtain; and the porous material prepared in the invention has a good CO2 trapping effect under an environmental condition, the maximum trapping capacity can reach 35%, the maximum CO2 / N2 selectivity can reach 32.69, and the material has a good CO2 trapping application prospect.

The invention discloses a near-full-spectrum fluorescent carbon point and a preparation method thereof, belonging to the field of carbon nano-luminescent materials. The emission peak wavelength of the carbon dot synthesized by this method is between 470nm-700nm, and the fluorescence emission peak of the carbon dot hardly changes with the change of the excitation wavelength, and has the characteristics of high fluorescence intensity and stable quantum yield. The synthesis preparation method comprises: organic acid containing carboxyl group and organic amine, the molar ratio of organic amine and organic acid is 1:0-1:1, adding a certain amount of deionized water, stirring evenly and transferring to a hydrothermal kettle , carry out a hydrothermal reaction, and after the reaction, the hydrothermal kettle is naturally cooled to room temperature to obtain an aqueous solution of carbon dots. The carbon dots synthesized by the invention have cheap and easy-to-obtain raw materials and are almost non-toxic, and the synthesis cycle of the carbon dots is short and the equipment for synthesizing the carbon dots is simple.

A synthesis method of a boron-nitrogen benzocarbazole derivative comprises the following steps: adding an o-amino styrene derivative, an aryl fluoroborate derivative, ammonia gas or organic amine, and a composite catalyst into a solvent in a nitrogen atmosphere, conducting heating to 25-100 DEG C, conducting reacting for 1-24 hours, and extracting, drying and recrystallizing the product to obtain the boron-nitrogen benzocarbazole derivative. In terms of per millimole of the aryl fluoborate derivative, the amount of the solvent is 5 mL, the amount of the o-amino styrene derivative is 1.2-1.5 mmol, the amount of the ammonia gas or the organic amine is 0.35-6 mmol, the amounts of the organic palladium and the phosphine compound are respectively 0.5-10% and 1-20% of the mole percentage of the aryl fluoborate derivative, and the amount of the alkaline compound is 1-6 mmol. The method is mild in reaction condition, wide in raw material application range, high in reaction specificity, high in yield and small in environmental pollution.

The present invention relates to a kind of novel synthetic method of 4a, 8a borazine and derivatives thereof, and its synthetic steps comprise: (1) diallylamine reacts with boron trichloride at low temperature, generates diallyl Amino boron dichloride; (2) diallylamino boron dichloride reacts with allyl Grignard reagent at low temperature to generate diallylamino diallyl borane; (3) diallyl Aminodiallylborane uses Grubbs first-generation catalyst to trigger olefin metathesis into ring reaction; (4) the ring-forming product and dichlorodicyanobenzoquinone undergo dehydroaromatization reaction to generate 4a, 8a-borazepine Naphthalene; (5) 4a, 8a-borazine and halogenated succinimide undergo a halogenation reaction under Lewis acid catalysis to generate 4a, 8a-borazine derivatives substituted by halogen at the 4 / 5 position. The invention has simple steps, cheap and easy-to-obtain raw material sources, mild reaction conditions, less side reactions, and simple and efficient post-treatment process.

The invention discloses a catalytic supported polymer. The structural formula is any one of a formula (I) or a formula (II). In the formulas, A is a urea or thiourea group, B is onium salt with positive charges, M is a comonomer, and X is a corresponding negative charge balance ion; and m represents the number of A and is any integer between 1 and 100000, and n represents the number of onium salt groups and is any integer between 1 and 100000. The invention also discloses a preparation method of the catalytic supported polymer, and application in catalysis of polymerization of one or more cyclic monomer bodies for obtaining amacromolecular polymer or a reaction of one or more cyclic monomers with carbon dioxide, carbon disulfide, carbon oxysulfide and carbon monoxide to obtain small molecular compounds and macromolecular polymers of cyclic carbonate cyclic lactone, and cyclic thiocarbonate. The catalytic supported polymer has relatively high catalytic activity and selectivity when applied to catalytic preparation of organic micromolecule and macromolecular polymers.

The invention discloses a novel synthesis method of (R)-9-(2-phosphorylmethoxypropyl)adenyl-di(isopropoxycarbonylmethyl)ester, which comprises the following steps; after tenofovir used as a raw material and triethylamine are salified in acetonitrile, evaporating to remove acetonitrile, remaining triethylamine and water in the tenofovir triethylamine salt, and carrying out condensation reaction with chloromethylisopropyl carbonate to obtain the (R)-9-(2-phosphorylmethoxypropyl)adenyl-di(isopropoxycarbonylmethyl)ester. The method disclosed by the invention has the advantages of cheap and accessible raw material, easily controlled technological operation, high yield and low cost, and is suitable for industrial production.

The invention discloses an ammonia nitrogen adsorbing material and a preparation method thereof. The preparation method specifically includes the steps that a sediment sample is selected, freeze-dried and ground into powder, the powder is screened, and sediment powder is obtained; under the condition that nitrogen is introduced, the sediment powder is anaerobically heated at the temperature of 500-800 DEG C; natural zeolite is cleaned, dried and ground into powder, the powder is screened, and natural zeolite powder is obtained; the heated sediment powder and the natural zeolite powder are evenly mixed, and the ammonia nitrogen adsorbing material is obtained. The preparation method further can include the steps of modification, heat treatment and the like. The material has the good ammonia nitrogen adsorbing effect, the ammonia nitrogen removal rate of water reaches 70%, and the material is suitable for removing ammonia nitrogen in natural water. The purpose of treating waste with waste is achieved through sediment in a lake, a raw material source is cheap and easy to obtain, and production cost is greatly reduced. The ecological risk to the lake water is low, the preparation method is simple and feasible, and market application prospects are good.

The invention discloses an idesia polycarpa fruit meal fish feed additive, and a preparation method and application thereof, which solve the problem that in the prior art, a feed rich in protein and fat is used for promoting the growth of fish pond algae, so that the water quality is poorer. The idesia polycarpa fruit meal fish feed additive is prepared from the following components in parts by weight: 1 to 8 parts of Chinese herb extract, 5 to 10 parts of idesia polycarpa fruit meal, 5 to 12 parts of corn flour, 10 to 20 parts of soyabean protein, 15 to 30 parts of earthworm powder, and 10 to 25 parts of bone meal, wherein the Chinese herb extract is prepared from the following raw materials in parts by weight: 10 to 30 parts of herba taraxaci, 12 to 30 parts of radix sophorae flavescentis, 13 to 28 parts of herba houttuyniae, and 14 to 22 parts of herba violae. The preparation method comprises the following steps of preparing the Chinese herb extract for standby application; weighing the components in parts by weight, mixing the idesia polycarpa fruit meal, the corn flour and the soyabean protein, smashing, adding the earthworm powder, the bone meal and the Chinese herb extract, uniformly mixing, drying, smashing, and obtaining the idesia polycarpa fruit meal fish feed additive.

The invention provides a method for preparing detomidine and the intermediate thereof. The method for preparing the intermediate of the detomidine comprises the steps that: 4-imidazolecarboxamide is condensed with 2, 3-Dimethylbromobenzene to produce 4-(2, 3- dimethylbenzoyl)-imidazole. The 4-(2, 3- dimethylbenzoyl)-imidazole can be reduced to produce the detomidine. The method of the invention has cheap and easy-to-get raw materials, easy-to-control technological processes, high yield factor and low cost and is suitable for being produced in an industrialized manner.

The invention provides a sound-absorbing light-insulating heat-preserving material and a preparation method thereof. The sound-absorbing light-insulating heat-preserving material comprises the following materials in percentage by volume: 10%-15% of resin, 55%-60% of clay or lime, 12-18% of cement, 12%-18% of gypsum and 12%-18% of fibers or rock wool. The method comprises the following steps of: firstly placing the resin, cement, clay or lime and gypsum into a container in proportion and stirring; after the resin, cement, the clay or lime and gypsum are uniformly stirred, slowly blowing the fibers or rock wool into the stirring container by utilizing an air blower, and stirring while blowing till the fibers or rock wool prepared in proportion is completely delivered into the stirring container; uniformly stirring the mixed material, naturally foaming and solidifying for 24 hours in a mold, then taking out of the mold, and drying for 5-7 days. The sound-absorbing light-insulating heat-preserving material provided by the invention is mainly used for the heat preservation and heat insulation of building houses and used for filling materials of bridges, highway isolation strips and the like and can meet the actual requirements for wind prevention, rain prevention, collision prevention, ventilation, light insulation, sound absorption, heat preservation, cold protection and the like of roads and bridges.

The invention provides compound fuel. The compound fuel is prepared from, by weight, 20-40% of methyl alcohol, 30-50% of naphtha, 5-20% of mixed aromatic hydrocarbons and 10-30% of coking toluene through chemical reactions. The invention further provides a preparation method of the compound fuel. The method includes the following steps of firstly, mixing and stirring mixed aromatic hydrocarbons and coking toluene to obtain cosolvent; secondly, mixing and stirring methyl alcohol and naphtha, adding the cosolvent obtained in the first step to the reaction system to obtain the finished product. The invention further provides application of the compound fuel as automotive petroleum. The fuel is prepared through the cosolvent according to the specific ratio, the mixing effect is good, and the water resistance and the cold start performance are good. The fuel can be independently used as automobile fuel to replace petroleum, and existing devices of automobiles do not need to be changed in use.

The invention belongs to the technical field of composite materials, and relates to a preparation method of a modified biomass charcoal composite chitosan-based adsorbent, which comprises the following steps: weighing potassium hydroxide, dissolving in deionized water, placing in an ice bath, dropwise adding acrylic acid for neutralization, adding modified biomass charcoal when the neutralization degree reaches 60-80%, and ultrasonically stirring uniformly to obtain a solution A; ultrasonically dissolving chitosan and disodium ethylene diamine tetraacetate in deionized water, and obtaining a solution B; uniformly mixing potassium persulfate and N'N-methylene bisacrylamide according to a volume ratio of 1: 1 to obtain a solution C, adding potassium persulfate serving as an initiator and N'N-methylene bisacrylamide serving as a cross-linking agent, carrying out ultrasonic treatment for 1 hour, reacting at 70 DEG C for 2 hours to obtain a hydrogel crude sample, soaking and washing with absolute ethyl alcohol for multiple times, carrying out vacuum drying at 70 DEG C for 24 hours, grinding into powder, drying and storing. The prepared adsorbent can be applied to adsorption of pollutants in water. The raw materials are low in cost and easy to obtain, the synthesis process is simple, the adsorption performance of the hydrogel is improved, waste is turned into wealth, and the product has a great application prospect.

The invention relates to the technical field of drying of meat products and particularly relates to a drying method of beef jerky. The drying method comprises the following steps: spraying bio-film liquid on the surface of pickled beef; then, putting the beef into a container containing modified kieselguhr; covering the upper surface of the beef with gauze and rice hull / fly ash mixture sequentially; then, putting the container into an oven; and performing constant-temperature treatment under the condition that the temperature is 35-47 DEG C until the moisture content of the meat products is less than or equal to 15%, thereby obtaining the beef jerky. The drying method provided by the invention has the characteristics of low cost, cheap and easily-available materials, no need of large-scaleor expensive equipment, low energy consumption and little pollution, effectively shortens the drying time and lowers the drying requirement. In addition, the obtained beef jerky is uniform and stablein quality, good in color and luster, good in taste and low in content of heterocyclic amines, and environmental friendliness and health of the beef jerky are improved.

The present invention discloses a high molecular weight polyester based on biomass as a monomer, a preparation method and a use thereof, and belongs to the field of polyester synthesis. A monomer of 2,5-dimethoxyterephthalate dimethyl ester and diol, and a catalyst are heated to 120 DEG C-180 DEG C under a protection of nitrogen for atmospheric pressure transesterification for 2 h-4 h to obtain atransesterification product; the transesterification product is heated to 220 DEG C to 250 DEG C under a high vacuum of less than 20 Pa for a polycondensation reaction for 2 h-4 h to obtain a polyester crude product; and finally, solvent extraction, precipitant precipitation, filtration, and drying are carried out to obtain the target product: high molecular weight polyester. The polyester obtained by the method has a weight-average molecular weight (Mw) value of 110,000-150,000 Da, and a molecular weight distribution Mw / Mn value of 1.7-2.2. The synthesized polyester has a high molecular weight, a high heat performance, good mechanical properties and other characteristics. The prepared high molecular weight polyester based on the biomass can be used as a main component of bottle-level polyester material processing and can also be used as a component raw material for preparation of other polyester processing materials.

The invention provides a method for synthesizing difluprednate from a sterol fermentation product. The sterol fermentation product, namely 9 Alpha-hydroxyl-androstane-1,4-diene-3,17-diketone (9 Alpha-OH-AD) obtained by fermenting phytosterol of which the content in byproducts of the grease industry is very high, serves as a starting raw material. The method comprises the following 15 reaction steps in total: dehydrating steride 9-hydroxyl to form a double-bond; adding 17-carbonyl with acetylene; dehydrating; producing 21-copper carbonyl under an acid condition; epoxidizing 16,17-double bond; oxidizing periodide and introducing 21-hydroxyl; performing ring opening on 16,17 Alpha-epoxy hydrobromate; hydrogenating for removing 16 Beta bromine; forming a ring on orthoester; performing ring opening; esterifying; epoxidizing 9,11-double bond-Beta; enolizing and esterifying; performing ring opening on 6-electrophilic fluoro; and performing ring opening on 9,11-epoxy fluoro. According to the method, steride 17 Alpha and 21-dyhydroxyl are efficiently built by means of periodide oxidization, epoxide ring-opening and debromination and an important intermediate type 11 compound is obtained; in the whole process, a large quantity of heavy metal pollutant chromium which is generated when producing corticoid medicines in the traditional industry is effectively avoided, so that the method is green, environment-friendly and suitable to industrialized production.

The invention provides a method for preparing detomidine and the intermediate thereof. The method for preparing the intermediate of the detomidine comprises the steps that: 4-imidazolecarboxamide is condensed with 2, 3-Dimethylbromobenzene to produce 4-(2, 3- dimethylbenzoyl)-imidazole. The 4-(2, 3- dimethylbenzoyl)-imidazole can be reduced to produce the detomidine. The method of the invention has cheap and easy-to-get raw materials, easy-to-control technological processes, high yield factor and low cost and is suitable for being produced in an industrialized manner.

The invention discloses a preparation method of 2,3,6-trichloropyridine, which uses 3-picoline and chlorine gas as raw materials, and uses a molecular sieve catalyst to catalyze one-step gas phase chlorination and detrichlorination in the presence of water vapor Methyl preparation of 2,3,6‑trichloropyridine. The molecular sieve catalyst is prepared by using molecular sieve raw powder as an active component. The raw material 3-picoline used in the present invention is a by-product of pyridine synthesized by the aldehyde-ammonia method, and the source is cheap and easy to obtain. Molecular sieve catalyst has strong processing ability. Using 3-picoline and chlorine gas as raw materials, adding appropriate amount of water, under the action of molecular sieve acid center and water vapor molecules, gas-phase chlorination and detrichloromethylation reactions occur, and one-step synthesis of 2,3 , 6-trichloropyridine, the process is simple, the product is pure, the conversion rate is high, and the yield can generally be maintained at more than 85%, the highest can reach 95%, and it has a good industrial application prospect.