1537 results about "Reaction step" patented technology

The invention discloses a synthetic method of a water soluble ultraviolet light absorber BP-9. The method mainly comprises the following process steps: (1) carrying out methylation on the main raw materials of 2, 2', 4, 4'-tetrahydroxyl benzophenone, a transition metal salt catalyst and a mixed solvent which is prepared from dichloroethane and anhydrous ethanol in equal parts by weight to obtain 2, 2'-dihydroxyl-4, 4'-dimethoxyl benzophenone; (2) carrying out sulfonation reaction on the main raw materials of methylate, sulfamic acid and C1-C3 halohydrocarbon to obtain 2, 2'-dihydroxyl-4, 4'-dimethoxyl benzophenone-5, 5'-disulfonic acid; and (3) carrying out neutral reaction on the main raw materials of sulfonated product, inorganic base and ethanol water to finally obtain the BP-9 product. The synthetic method disclosed by the invention is few in reaction step, low in cost, high in product purity and stable in quality, and raw materials are easily available.

The present invention relates to a method and an apparatus for producing nitrile with controlled spray liquid input pressure. According to the manufacturing method, spraying liquid can be atomized, the contact area with ammonia is increased, and the mass transfer efficiency is improved. The present invention relates to a method for producing nitrile, comprising a step (referred to as a reaction step) for producing a nitrile-containing reaction product by subjecting a hydrocarbon raw material to an ammoxidation reaction, and a step (referred to as a cooling step) for cooling the reaction product by spraying a spray liquid onto the reaction product by means of a spraying device, the spraying device comprises a spraying liquid inlet, a first spraying pipe in fluid communication with the spraying liquid inlet, and a plurality of second spraying pipes which are in fluid communication with the first spraying pipe, are perpendicular to the first spraying pipe and extend towards the two sides of the first spraying pipe. The first spraying pipe is communicated with the first spraying pipe through fluid, the second spraying pipe is communicated with the second spraying pipe through fluid, the third spraying pipes are communicated with the second spraying pipe through fluid and extend towards the two sides of the second spraying pipe perpendicular to the second spraying pipe, the nozzles are located at the tail ends of the third spraying pipes and communicated with the third spraying pipes through fluid, and in the cooling step, the spraying liquid input pressure of a spraying liquid inlet is controlled to be 0.06-1.00 MPaG.

The invention provides a method for preparing squaric acid and a method for preparing a lithium supplement agent of lithium squarate. The method for preparing squaric acid comprises the steps of preparing an intermediate I, preparing an intermediate II and preparing squaric acid. The method for preparing the squaric acid is a novel squaric acid synthesis route, and the squaric acid is obtained through cycloaddition / substitution reaction of perchloroprene serving as an initial raw material and morpholine, hydrolysis / rearrangement reaction in a buffer system and acid hydrolysis reaction in sequence. The method for preparing squaric acid has the advantages of simple reaction steps, mild reaction conditions, high yield, low cost and the like. The invention also provides a method for preparing the lithium squarate lithium supplement agent, and the prepared squaric acid and lithium-containing alkali are blended in a solvent for reaction to generate the lithium squarate. The method for preparing the lithium squarate lithium supplement has the advantages of simple reaction steps, mild reaction conditions, high yield, low cost and the like.

The invention provides a production process for reducing the nitrogen content in reagent-grade sulfuric acid, and relates to the technical field of sulfuric acid. Comprising the following steps: adding urea solid powder into sulfuric acid at 55-65 DEG C according to the mass ratio of urea to sulfuric acid of (0.001-0.01): 100, and stirring until the urea solid powder is completely dissolved; s100, heating the mixture in the step S100 to 83-87 DEG C in a gradient manner, adding ammonium sulfate powder according to the mass ratio of ammonium sulfate to sulfuric acid of (0.05-0.1): 100 in the heating process, and stirring to react for 0.8-1.2 hours; performing reduced pressure distillation on the sulfuric acid after the reaction in the step S200 at 80-150 DEG C, introducing inert gas in a synchronous pulse manner for purging in the heating process, repeating for 2-3 times, and collecting a main fraction; treating tail gas. According to the method, the total nitrogen content and the content of NH4 < + > ions and NO3 <-> ions in the reagent-grade sulfuric acid are effectively reduced, the electronic-grade sulfuric acid is obtained, and the yield of the sulfuric acid can reach 97.5%.

The invention belongs to the field of preparation of medical intermediates, and particularly relates to a preparation method of an On-DNA sulfinic acid structure compound. The method for preparing the On-DNA sulfinic acid structure compound comprises a step of oxidizing On-DNA thiol (phenol) into the On-DNA sulfinic acid structure compound under alkaline and heating or illumination conditions, a solvent used in the reaction step is a mixed solution of water, dimethyl sulfoxide, N, N-dimethylformamide, acetonitrile, ethanol or tetrahydrofuran, the reaction temperature is not more than 80 DEG C, and the reaction time is not more than 2 hours. And the illumination wavelength ranges from 365 nanometers to 535 nanometers. The On-DNA sulfinic acid structure compound obtained in the invention can be directly used for constructing a structure compound with a sulfonyl group, the reaction condition is mild and convenient, a new method and a new idea are provided for construction of a DNA coding compound library, and the On-DNA sulfinic acid structure compound has a very good application prospect in lead drug development.

The invention relates to the technical field of chemistry and chemical engineering, and particularly discloses a production process of low-molecular-weight bisphenol A type polycarbonate polyether polyol and an intelligent gas control method, the production process comprises a premixing step, a feeding step, a CO2 pressure maintaining step, a heating step and a circular reaction step, in the circular reaction process, the reaction temperature is monitored in real time, and the reaction time is shortened; and performing multi-dimensional time sequence analysis on the time sequence data of the reaction temperature by adopting an intelligent industrial control technology so as to excavate the time sequence change trend of the reaction temperature and the fluctuation information of the temperature change rate, and judging whether CO2 gas needs to be supplemented in the current temperature state or not through an intelligent classification algorithm by taking the fluctuation information as an adjustment basis. Therefore, the temperature fluctuation in the reaction process can be responded in real time, and the self-adaptive supplement control of the CO2 gas is realized to ensure that the temperature of the reaction system is maintained in a safe and efficient range, so that the problem of yellowing of the temperature-sensitive micromolecular polycarbonate polyether polyol product is solved.

The invention relates to a multi-carbonyl enol compound which has a structure as shown in a general formula I. The compound has a plurality of carbonyl enol structures. The invention further provides a synthesis method of the compound, the multi-carbon-based enol compound is prepared through an acylation reaction, a Willgerodt-Kindler reaction, a Vilsmeier-Haack-Arnold reaction and a hydrolysis reaction, the intermediate reaction step does not involve a noble metal catalyst, and the synthesis route is economical and efficient. The invention also provides a diazo naphthoquinone photoinitiator prepared by esterification and condensation of the compound as a monomer and diazo naphthoquinone sulfonyl chloride, and an application of the photoinitiator in I-line photoresist configuration. The compound disclosed by the invention is highly symmetrical in structure, has a unique enol interconversion and multi-carbonyl and hydroxyl functional group coexisting structure, and has an extremely wide application prospect.

The present invention provides a method for preparing coffee diglyceride, belonging to the field of biotechnology. The present invention provides a method for preparing coffee diglyceride, comprising the following steps: 1) mixing coffee oil and glycerol, then adding a composite catalyst and choline chloride to fully mix to obtain a mixed solution; 2) subjecting the mixed solution to catalytic reaction, filtration, and molecular distillation in sequence to obtain coffee diglyceride; the catalytic reaction steps include: first vacuum catalysis, first nitrogen bubbling; second vacuum catalysis, second nitrogen bubbling, and adding a composite catalyst; third vacuum catalysis, third nitrogen bubbling; fourth vacuum catalysis, fourth nitrogen bubbling, and adding a composite catalyst; fifth vacuum catalysis, fifth nitrogen bubbling. The above preparation method is simple, low-cost, and the obtained coffee diglyceride has a high yield, high purity, and good flavor.

The invention belongs to the field of chemistry and chemical engineering, and discloses a method for preparing high-purity 1, 4-dioxane-2-ketone at low cost. A large amount of high-purity 1, 4-dioxane-2-ketone can be prepared at one time by taking a large amount of glycollic acid or glycollic acid derivatives and ethylene oxide as raw materials and adopting a one-step synthesis process route and a purification mode suitable for industrial production. According to the method, cheap bulk commodities are adopted as raw materials, and high-value conversion of low-value chemicals is achieved; according to the method disclosed by the invention, the 1, 4-dioxane-2-ketone is rapidly synthesized in one step under mild conditions without a catalyst or with a trace amount of a catalyst, so that the synthesis yield of a target product is improved, the reaction steps are greatly shortened, the energy consumption is greatly reduced, and the production cost is obviously reduced.

The invention provides an antistatic polypropylene material as well as a preparation method and application thereof, and belongs to the technical field of polypropylene materials. The preparation method comprises the following steps: modifying graphene, preparing a graphene / titanium dioxide compound, reacting, and performing extrusion molding. The method comprises the following reaction steps: putting a functionalized graphene / titanium dioxide compound into a reaction container, introducing N, N-dimethylformamide, uniformly stirring, adding modified graphene, dicyclohexylcarbodiimide and 4-dimethylaminopyridine, heating to 73-77 DEG C, carrying out ultrasonic treatment, and after ultrasonic treatment is finished, carrying out heat preservation stirring for 1.8-2.2 hours to obtain the graphene / titanium dioxide composite material. Then heating to 116-123 DEG C at the speed of 1.7-2.3 DEG C / min, stirring for 1.8-2.2 hours while keeping the temperature, after stirring is finished, filtering, washing, freeze-drying, and naturally recovering to room temperature, so as to obtain a graphene-graphene / titanium dioxide compound; the antistatic polypropylene material prepared by the invention is good in antistatic property, excellent in mechanical property and good in aging resistance.

The invention discloses a method for efficiently synthesizing berberine hydrochloride by adopting a solid resin catalyst, and belongs to the field of medical chemical synthesis. The berberine hydrochloride can be efficiently synthesized by optimizing reaction steps and reaction conditions and adopting a solid resin catalyst for catalytic reaction. The method has relatively high reaction yield and product purity, and the catalyst can be repeatedly used, so that the environmental pollution and the production cost are effectively reduced.

The invention relates to a nitrogen-containing heterocyclic compound as well as a preparation method and application thereof, belongs to the technical field of heterocyclic compound synthesis, and solves the problems of low reaction efficiency and high energy consumption caused by the fact that an existing method for synthesizing an indole maleimide derivative needs to be carried out step by step. The preparation method comprises the following steps: step 1, adding indoleacetamide and a nucleophilic reagent into a mixed solution, and reacting; 2, performing post-treatment to obtain a nitrogen-containing heterocyclic compound; the mixed solution comprises alkali, an additive and an organic solvent; the alkali comprises one of triethylamine (Et3N), N, N-diisopropylethylamine, pyridine and 1, 8-diazabicyclo [5.4. 0] undec-7-ene, and the alkali comprises one of 1, 8-diazabicyclo [5.4. 0] undec-7-ene.

The present invention discloses a pimobendan intermediate synthesis method, which comprises: 1, carrying out a Friedel-Crafts acylation reaction on a compound I and a compound A in an aprotic solvent under the effect of a Lewis acid to generate a compound II; 2, ether is used as a solvent, under the alkaline condition, the compound II and dimethyl malonate or diethyl malonate are subjected to a substitution reaction, the generated compound is subjected to a hydrolysis reaction in an aqueous alkali solution, and a compound III is generated; and 3, heating the compound III under the conditions of hydrazine hydrate and acid to generate a compound IV, namely the pimobendan intermediate. The synthesis method cancels a nitration reaction step which is high in risk and generates a large amount of waste acid water, and is short in route step and simple to operate.

The invention relates to the field of biological medicine preparation, and provides a semi-synthesis preparation method of semeglutide and a preparation method of a semeglutide side chain, the semi-synthesis preparation method comprises the following steps: 1, in the presence of a first base catalyst, mixing a compound SMG-1 solution with a compound III solution, reacting to obtain a compound IV, and filtering to obtain a compound III; wherein the addition amount of the first base catalyst is such that the pH value of the SMG-1 solution is 11.2-11.6; 2, in the presence of a coupling agent and a second base catalyst, a compound IV solution and a compound SMG-3 solution are mixed and coupled to obtain a compound V, and the pH value in the step 2 is 9.5-10.0; and 3, carrying out deprotection on the compound V by using a deprotection agent to finally obtain the semeglutide. The method provided by the invention has the advantages of few reaction steps, reduced cost, high semeglutide purity and high yield, and is suitable for large-scale industrial production.

The invention relates to the field of medicine synthesis and preparation, in particular to a synthesis method of toxyanib phosphate. The use amount of acetic acid is greatly reduced in the preparation process, so that excessive acid does not need to be neutralized in the post-treatment process, and a large amount of wastewater is not generated; in addition, the use amount of sodium nitrite is reduced, and the environment and health are facilitated; the enamine reduction reaction does not use acetic acid as a solvent and a hydrogenation reaction catalyzed by heavy metal palladium, so that the safety of the reaction is improved, and the purity of the product is also improved; a decarboxylation reaction and a Vilsmeier-Haack reaction are carried out by a one-pot method, so that the reaction steps are reduced, and the product purity is improved; when aldol reaction is carried out in side chain splicing, side reaction and generation of isomer impurities are reduced. The method is short in route, mild in reaction condition, low in equipment requirement and convenient to operate, industrial production is easy to achieve, and a complex purification method is not needed.

The invention discloses a method for preparing inositol, particularly relates to a method for converting glucose into inositol through in-vitro multi-enzyme catalysis, and belongs to the field of enzyme catalysis preparation of inositol. According to the invention, the phosphoglucose synthase capable of realizing phosphorylation of glucose by using inorganic phosphate is screened, and the inositol can be generated through conversion by taking glucose as a substrate, so that a novel method for synthesizing the inositol through enzyme catalytic conversion is provided. In addition, the invention further provides hexokinase capable of improving the yield of inositol, and the conversion efficiency of glucose is greatly improved. Furthermore, the invention provides a multi-enzyme molecular machine containing the glucose phosphate synthase and / or hexokinase, the multi-enzyme molecular machine is applied to preparation of inositol, and the reaction steps are simple, green and pollution-free.

The invention discloses a core-shell catalyst for preparing polyoxymethylene dimethyl ethers through methanol dehydrogenation and preparation and application thereof.The catalyst comprises an acidic molecular sieve, a metal active component and aluminum-containing mesoporous silica, the acidic molecular sieve serves as a core structure, the metal active component is coated on the surface of the acidic molecular sieve to form a first coating layer, and the aluminum-containing mesoporous silica serves as a second coating layer; and the aluminum-containing mesoporous silica is coated on the surface of the metal active component to form a second coating layer. According to the prepared core-shell catalyst, a middle acidic molecular sieve and aluminum-containing mesoporous silica on the outermost layer are used as acidic sites, a metal active component on the middle layer is used as a dehydrogenation site, and the two reaction sites are integrated to construct a bifunctional catalyst; in-situ coupling of two-step reaction of preparing formaldehyde through methanol dehydrogenation reaction and preparing polyoxymethylene dimethyl ether through condensation reaction of methanol and formaldehyde is realized, so that the reaction steps are simplified, and the reaction selectivity is also improved.

The invention discloses a method for preparing 1, 2, 3-trichloropropene with high selectivity by dehydrochlorination of 1, 2, 2, 3-tetrachloropropane, and belongs to the technical field of catalysis. The method comprises the following steps: stirring 1, 2, 2, 3-tetrachloropropane and a sodium hydroxide solution under the conditions of normal pressure and 40-100 DEG C for reflux reaction, after the reaction is finished, cooling the reaction liquid to room temperature, separating the liquid by using a separating funnel, rectifying the obtained oil phase to obtain 1, 2, 3-trichloropropene, adding an improver into the reaction system, and carrying out solid-liquid separation to obtain the 1, 2, 3-trichloropropene. The improver is a complex system composed of a metal salt and a bidentate phosphine ligand or a metal composite oxide. The method provided by the invention has the advantages of fewer reaction steps and simpler equipment, the yield of 1, 2, 3-trichloropropene is as high as 86%, the conversion rate of 1, 2, 2, 3-tetrachloropropane is as high as 92%, the selectivity of the target product is as high as 98%, and the conversion rate and the selectivity of the target product are remarkably improved.

The invention discloses a trimethoprim hapten as well as synthesis and application thereof. The structure of the trimethoprim hapten is as shown in a formula I. The trimethoprim hapten provided by the invention can fully expose the antigenic determinant of trimethoprim and maintain the spatial conformation of trimethoprim, has good immunogenicity, and is mild in synthesis conditions, few in reaction steps, high in yield and capable of reducing the cost of raw materials. The trimethoprim colloidal gold detection product provided by the invention has the characteristics of strong specificity and high sensitivity, can realize accurate and rapid detection of trimethoprim in a sample, and has no cross reaction with other drugs. And the formula I of the # imgabs0 # is shown in the specification.

The synthesis method comprises the following steps: S1, adding furandicarboxylic acid into a reaction container, adding a certain amount of methanol, adding a double-acid-site strong acid solid catalyst, starting stirring, controlling the reaction temperature to carry out esterification reaction, and after the reaction is finished, filtering, washing and drying to obtain furandihydrazide; separating out the double-acid-site strong acid solid catalyst to obtain clear liquid, namely dimethyl furandicarboxylate; s2, transferring dimethyl furandicarboxylate serving as a raw material into another reaction container, adding a certain amount of sodium formate serving as a catalyst, then adding a proper amount of hydrazine hydrate, controlling the reaction temperature, keeping a reflux state, reacting for a period of time, cooling to room temperature after the reaction is finished, and performing centrifugal separation to obtain white solid furandihydrazide. The synthesis method has the advantages of simple reaction steps, no need of toxic and harmful catalysts, mild reaction conditions, high conversion rate and high yield, and can realize efficient, green and low-cost production of furandihydrazide.

The invention provides a preparation method and application of an asymmetric dicyclopentadienyl dialkoxy zirconium compound, and the preparation method comprises the following steps: (1) mixing a solvent with ZrCl4 and sodium cyclopentadienyl CpNa, and carrying out a reaction to obtain CpZrCl3; (2) the CpZrCl3 obtained in the step (1) and R1 substituted sodium cyclopentadienyl R1CpNa are subjected to a mixed reaction, and (R1Cp) CpZrCl2 is obtained; and (3) mixing the (R1Cp) CpZrCl2 obtained in the step (2) with alkoxy sodium salt R2Na, and carrying out a reaction so as to obtain the asymmetric dicyclopentadiene dialkoxy zirconium compound. According to the method, the substitution reaction of three sodium salts is used for replacing the ligand replacement reaction in the prior art, so that the reaction steps are shortened, the use of unnecessary raw materials is avoided, the production cost is reduced, and the obtained target product is high in yield and high in purity.

The invention discloses a paclobutrazol hapten as well as synthesis and application thereof. The structure of the paclobutrazol hapten is shown as a formula I. Compared with 3-6 carbon chains, the synthetic method of the paclobutrazol hapten provided by the invention has the characteristics of mild reaction conditions, high yield, few reaction steps and capability of reducing the cost of raw materials. The paclobutrazol colloidal gold detection product provided by the invention has the characteristics of strong specificity, high sensitivity and the like, can realize accurate detection of paclobutrazol in a sample, and has no cross reaction with other drugs. # imgabs0 #

The invention provides a continuous process for preparing aromatic hydrocarbon by supercritical carbon dioxide hydrogenation, which comprises the following steps: 1) adding a reaction liquid containing a solvent and a catalyst into a reaction kettle, spraying supercritical carbon dioxide and hydrogen into a reactor by adopting a Venturi ejector, and contacting with the catalyst in the reaction kettle to react; (2) after the reaction in the step (1), the gas in the reactor is sequentially subjected to primary condensation and secondary condensation to respectively condense the solvent and the water, the solvent of the primary condensation returns to the reaction kettle, the water of the secondary condensation is discharged, and the gas after the secondary condensation sequentially passes through an absorption tower and a desorption tower to capture non-aromatic hydrocarbon, the residual gas is used as recycle gas and returns to the Venturi ejector to enter the reaction kettle; and (3) pressurizing the reaction liquid discharged from the reaction kettle after the reaction in the step (1) through a circulating pump, feeding the reaction liquid into a heat exchanger to remove reaction heat, dividing the reaction liquid subjected to heat exchange into two streams through a cross-flow filter, feeding one stream of penetrating fluid into a rectification device, and feeding the other stream of concentrated liquid back to the reaction kettle for continuous reaction.

The invention relates to a method for directly preparing (methyl) anisole from phenol and methanol, which comprises the following steps: under the action of a composite catalyst, phenol and methanol are catalyzed to generate methyl anisole, and the composite catalyst is prepared by mixing a Ho / beta molecular sieve catalyst and Ti / UiO-66 according to a mass ratio of Ho / beta: Ti / UiO-66 of 0.3-0.6: 1. According to the process, the reaction steps are simple, synthesis is achieved through one step, the total selectivity of methyl anisole reaches 76% or above, and continuous and stable operation can be conducted for 3000 h.

To provide means for producing silver nanoparticles having a narrow particle size distribution and a fine particle size in a high yield.SOLUTION: A method for producing silver nanoparticles comprises: a raw material preparation step for preparing an aqueous solution of a silver salt and an aqueous solution of a reducing agent including an alkali metal hydroxide or an alkaline earth metal hydroxide; a temperature-raising step for mixing the aqueous solution of the silver salt and the aqueous solution of the reducing agent and raising the temperature of the mixture to a reaction temperature of 100°C or higher within 30 seconds from the start of mixing; and a reaction step for maintaining the mixture obtained in the temperature-raising step at the reaction temperature.SELECTED DRAWING: Figure 1

The invention relates to a preparation method of rotigotine, which solves the technical problems of unreasonable reaction steps and higher production cost in the prior art, and comprises the following steps: carrying out chiral amination reduction reaction on 5-methoxy-2-tetralone, chiral phosphate, pinacol borane and p-methoxyaniline to obtain a compound 1; reacting the compound 1 with bromopropane to obtain a compound 2; reacting the compound 2 with ceric ammonium nitrate to obtain a compound 3; dissolving the compound 3 in hydrobromic acid, and reacting to obtain a compound 4; and carrying out a reaction on the compound 4 and 2-thiophene ethyl methanesulfonate to obtain a crude product rotigotine. The method can be applied to the field of preparation of rotigotine.

The invention discloses a method for preparing poly (butylene adipate-co-terephthalate) by a one-step method. The method comprises the steps of terephthalic acid esterification, adipic acid esterification, secondary esterification of terephthalic acid esterification liquid and adipic acid esterification liquid, and condensation polymerization, wherein terephthalic acid esterification and adipic acid esterification are synchronously carried out; in the terephthalic acid esterification process, a catalyst and a heat stabilizer are mixed and heated to obtain a mixed catalyst, and after terephthalic acid esterification reaction generates water, the mixed catalyst is added into a reaction system in a manner of feeding under the liquid level, so that on one hand, hydrolysis of the catalyst is reduced, and the catalytic efficiency of the catalyst is improved; on the other hand, the heat exchange efficiency is reduced and the energy consumption is increased due to the fact that a catalyst hydrolysis product covers a heat exchange pipeline; under the condition of not supplementing a catalyst, the synthesized product with qualified indexes such as PBAT melt index, color value, terminal carboxyl group and the like can be realized through subsequent secondary esterification and polycondensation.

The invention relates to an LDHs (Layered Double Hydroxides) bifunctional catalyst for preparing CO through CO2 selective absorption in-situ relay coupling low-energy-consumption conversion as well as a preparation method and application of the LDHs bifunctional catalyst. Controlling the thickness of a laminate to prepare an ultrathin NO3-intercalated LDHs carrier, adding a metal salt solution in N2 atmosphere, and reducing metal to obtain the catalyst. The method comprises the following steps of: applying the LDHs to a reaction device, introducing CO2-containing feed gas, realizing the trapping process that CO2 is stored between the LDHs in the form of CO3 < 2-> in the presence of water vapor, and then performing low-temperature in-situ conversion on the CO3 < 2-> in the interlayer into a high-added-value product in an H2 atmosphere. After the reaction, the catalyst continues to selectively capture CO2 and is repeatedly used, and CO2 capture-in-situ conversion integration is achieved. According to the invention, H < + > transfer and interlayer carbonate reduction are promoted; meanwhile, desorption of a CO intermediate on the surface of the catalyst is accelerated, subsequent reaction steps are prevented, and therefore the process of preparing CO from CO2 at low temperature is achieved, energy consumption is low, efficiency is high, and selectivity is high.

According to the preparation method of the oral PCSK9 inhibitor intermediate, the used intermediate and the synthesis method of the intermediate, the key intermediates are innovatively designed and synthesized, the operation conditions of the steps are mild, the yield is high, the cost is low, toxic impurities are few, the steps are few, and industrial production is facilitated. The synthesis thought of the oral PCSK9 inhibitor intermediate MK-A is constructed through the key intermediates, the 5-bromo-1-pentene is innovatively used as the starting material, the reaction steps are shortened, the yield is obviously improved, the cost is reduced, and the method is suitable for large-scale production.

The invention discloses a reagent combination, an analyzer and a detection method for detecting beryllium element content in a water sample. The reagent combination is composed of a color developing agent, a masking agent, a buffer solution and a catalytic solution. The color developing agent comprises chrome cyanine R; the masking agent comprises EDTA (Ethylene Diamine Tetraacetic Acid), ascorbic acid, tartaric acid and ethylene glycol amine; the buffer solution comprises ammonium acetate and hydrochloric acid; the catalytic liquid comprises hexadecylpyridinium chloride. Compared with a standard method, the adopted reagents have the advantages that the reaction steps are simplified, the stability of the reagents is better, the shelf life is longer, the reagents such as ammonia water and hexamethylenetetramine used in the standard method not only have pungent smell and larger environmental pollution, but also are easy to volatilize and deteriorate, and are not beneficial to long-term storage, so that the long-term measurement result is deviated, and the accuracy of the detection result is improved. Reagents used in the method do not have the defects, and can be stored for a long time at normal temperature, so that the method can be suitable for unattended automatic instruments and automatic water quality monitoring stations.