83 results about "Chlorobenzoic Acids" patented technology

The invention belongs to the field of preparation of halogen-containing substituted benzoic acid, and particularly relates to a method for preparing o-chlorobenzoic acid through hydrogenation selective debromination. According to the invention, hydrogen is used as a reducing agent, a palladium catalyst is used as a catalyst, a methanol aqueous solution is used as a solvent, and 2-chloro-3-bromobenzoic acid, 2-chloro-5-bromobenzoic acid or a mixture thereof are used as raw materials to prepare o-chlorobenzoic acid. According to the method, debromination is controlled through selective hydrogenation instead of dechlorination, so that generation of a byproduct benzoic acid is inhibited. The scheme is reasonable in design, simple in process and mild in reaction condition, and a new thought is provided for the synthesis method of o-chlorobenzoic acid.

The invention relates to the technical field of organic synthesis processes, and provides a method for preparing methyl o-chlorobenzoate from o-chlorotoluene, which comprises the following steps: adding o-chlorotoluene, acetic acid and a supported catalyst into a mixing kettle, heating to 60-120 DEG C, and stirring to obtain a mixed solution; pouring the mixed solution into a reaction kettle, introducing air to pressurize, heating to 130-180 DEG C, reacting for 2-4 hours, discharging, cooling, filtering, washing and distilling to obtain o-chlorobenzoic acid; the method comprises the following steps: mixing o-chlorobenzoic acid and methanol, stirring, adding a catalyst, heating to 70-90 DEG C, reacting for 2-4 hours, cooling, extracting, washing, standing and layering to obtain an upper phase, namely methyl o-chlorobenzoate. The preparation method has the advantages of low production cost, less waste gas and waste water, and realization of the coordinated development of economic benefits and environmental benefits, and the methyl o-chlorobenzoate prepared from o-chlorotoluene has the advantages of high yield, high purity, and good application value.

The invention discloses a preparation method of chloroprocaine hydrochloride, and belongs to the technical field of chloroprocaine hydrochloride synthesis. Comprising the following steps: (1) preparing 4-amino-2-chlorobenzoic acid: dissolving 2-chloro-4-nitrobenzoic acid in a solvent, and uniformly stirring; adding a ruthenium catalyst Ru / SNC into the system, and carrying out heat preservation reaction in a hydrogen atmosphere; the 4-amino-2-chlorobenzoic acid is obtained through a reaction; (2) preparation of chloroprocaine hydrochloride: dissolving 4-amino-2-chlorobenzoic acid, 2-chloroethyl diethylamine and a solid base catalyst K / r-GO in a reaction solvent, and carrying out an esterification reaction; the 2-(diethylamino)-2-chlorine-4-nitrobenzoic acid ethyl ester is obtained; and then salifying and drying to obtain the chloroprocaine hydrochloride. The catalyst provided by the invention realizes efficient catalytic reaction at lower temperature and pressure, can be recycled for dozens of times, and is suitable for large-scale industrial production.

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 2-sulfydryl-6-chlorobenzoic acid, which comprises the following steps: dissolving chlorobenzoic acid in dimethyl sulfoxide, adding sodium hydrogen sulfite, and stirring at room temperature; the preparation method comprises the following steps: dissolving mercaptobenzoate in dimethyl sulfoxide, adding sodium carbonate and dimethylamino, and reacting at high temperature; cooling to room temperature, and adjusting the pH value to be neutral by using dilute acid; adding into diethyl ether, uniformly mixing, adding into dilute acid, and standing for layering to obtain 2-sulfydryl-6-chlorobenzoic acid; the preparation method of the chlorobenzoic acid comprises the following steps: mixing parachlorotoluene with water, adding a supported catalyst, stirring and heating; after the temperature rises to 80 DEG C, adding potassium permanganate in batches for reaction; and filtering, adjusting the pH value to be acidic by using dilute acid, and then carrying out suction filtration and drying to obtain the chlorobenzoic acid. According to the preparation method disclosed by the invention, chlorobenzoic acid and mercaptobenzoate are subjected to a reaction to obtain 2-mercapto-6-chlorobenzoic acid with high yield; the method has the characteristics of simplified operation, energy consumption reduction, shortened production period and low production cost.

The present invention discloses a process for preparing m-chloroperbenzoic acid by using a molecular sieve catalyst, belonging to the technical field of chemical catalytic preparation, and comprising the following steps: S1, dissolving m-chlorobenzoic acid in an organic solvent, adding the molecular sieve catalyst, uniformly stirring, and then dropwise adding an aqueous oxidant solution with a mass fraction of 15% to 30% for an oxidation reaction; S2, after the oxidation reaction is completed, separating the molecular sieve by using a filter for the next reaction; S3, after separation, extracting and separating the organic phase, distilling and recovering the organic solvent to obtain m-chloroperbenzoic acid crystals. The present invention overcomes the defects and deficiencies in the existing process methods, such as low effective yield and serious wastewater pollution. A solid molecular sieve is used as the catalyst. The catalyst has stable properties, simple separation, the solvent can be recycled and reused in the process, the product yield is high, environmental problems caused by other oxidation methods are avoided, and it is beneficial to large-scale industrial production.

The invention relates to a dapagliflozin impurity and a preparation method thereof, 5-bromo-2-chlorobenzoic acid (IV) is used as a raw material, (5-bromo-2-chlorphenyl) (4-ethyoxyl phenyl) ketone (III) is prepared through chlorination and Friedel-Crafts acylation, (5-bromo-2-chlorphenyl) (4-ethyoxyl phenyl) methanol (II) is obtained through reduction, and the benzhydryl ether impurity (I) is obtained through condensation under the catalysis of iodine. The preparation method has the advantages of simple operation, low cost, easily available raw materials and good product purity.

The application belongs to the technical field of medicine synthesis, and particularly relates to a preparation method of furosemide. The preparation method of furosemide comprises the following steps: chlorosulfonation: reacting chlorosulfonic acid and 2,4-dichlorobenzoic acid, hydrolyzing, filtering, and obtaining 2,4-dichloro-5-sulfonyl chlorobenzoic acid; amination: adding 2,4-dichloro-5-sulfonyl chlorobenzoic acid into ammonia water, reacting, neutralizing, filtering, purifying, and obtaining 2,4-dichloro-5-sulfonamidobenzoic acid; condensation: reacting 2-furfurylamine and 2,4-dichloro-5-sulfonamidobenzoic acid, and obtaining furosemide crude product; decolorization: adding the furosemide crude product into a saturated sodium bicarbonate solution, adding activated carbon for decolorization, neutralizing, and crystallizing, and thus furosemide product is obtained. The raw material used in the application is easy to obtain and low in price, the comprehensive reaction period is short, the amount of hazardous waste generated is small, the prepared furosemide is high in purity and high in total yield, the comprehensive cost of the whole preparation process is low, and the application is suitable for industrial production.

The invention discloses a preparation method of a mesalazine intermediate, which comprises the following steps: carrying out nitration reaction by using 2-chlorobenzoic acid as an initial raw material, and hydrolyzing in an alkaline aqueous solution to obtain a synthetic intermediate 5-nitrosalicylic acid of mesalazine. The method is mild in process condition, the used raw materials are cheap and easy to obtain, dangerous and toxic reaction conditions are not involved, the content of 3-site isomer impurities in the intermediate 5-nitrosalicylic acid product is 5% or below, and the total content of other impurities is lower than 0.5%.

This invention belongs to the field of organic electrochemical synthesis and microchemical technology, and relates to a method for preparing 2-chlorobenzoic acid by electrochemical reduction debromination in a continuous flow microreactor. The method includes: dissolving 3-bromo-2-chlorobenzoic acid, a supporting electrolyte, and a proton source in a polar aprotic solvent to prepare a cathode reaction solution; continuously feeding this solution into the cathode channel of a microchannel electrochemical reactor using a metering pump, while simultaneously pumping the anolyte into the anode channel; connecting a DC power supply and conducting a selective electrochemical debromination reaction under set current density, reaction temperature, and material residence time conditions; and obtaining high-purity 2-chlorobenzoic acid from the outlet material through gas-liquid separation, neutralization, extraction, and recrystallization. This invention combines a continuous flow microreactor with electrochemical debromination technology, significantly enhancing mass and heat transfer, resulting in a shorter reaction time, higher conversion and yield, and the addition of a reducing agent, ease of scale-up, and intrinsic safety, demonstrating promising industrial application prospects.

The invention provides a synthesis method of 2-amino-3-methyl-5-chlorobenzoic acid, which comprises the following steps: respectively pumping m-xylene and liquid chlorine into a microchannel reactor for reaction, and purifying to obtain 2-chloro m-xylene; s2, adding a catalyst into the 2-chloro-m-xylene obtained in the step S1, introducing the mixture into a micro-channel reactor, introducing an oxidizing reagent, carrying out a reaction, and purifying a product to obtain 2-chloro-3-methyl benzoic acid; s2, dissolving the 2-chloro-3-methyl benzoic acid obtained in the step S2 and alkali in a solvent 1, introducing ammonia gas, reacting under the pressure condition, and purifying a product to obtain 2-amino-3-methyl benzoic acid; and S3, diluting the 2-amino-3-methyl benzoic acid obtained in S3 with a solvent 2, pumping the diluted 2-amino-3-methyl benzoic acid into a tubular reactor, introducing liquid chlorine for reaction, and purifying the product to obtain the 2-amino-3-methyl-5-chlorobenzoic acid. Ammonia gas is adopted as a nucleophilic reagent to avoid nitration reaction, so that the amount of acid wastewater can be reduced from the source, hydrogenation reduction is not needed, and the route atom utilization rate is greatly increased.

The invention provides a method for recovering an effective ingredient in p-chlorobenzaldehyde wastewater, including the preparation, refinement and wastewater recovery process of p-chlorobenzaldehyde, wherein the preparation of p-chlorobenzaldehyde includes chlorination reaction, hydrolysis reaction and neutralization reaction, the oily substance after the neutralization reaction enters the p-chlorobenzaldehyde refining process, the wastewater after the neutralization reaction enters the recovery process, the wastewater after the p-chlorobenzaldehyde neutralization reaction is passed into an oxidation reactor in the recovery process, an active oxidant is provided in the oxidation reactor, the oxidant is instantly generated as the wastewater is passed, and the p-chlorobenzaldehyde in the wastewater is oxidized to p-chlorobenzoic acid. The wastewater of p-chlorobenzaldehyde is used for the production and preparation of p-chlorobenzoic acid, the p-chlorobenzoic acid in the wastewater is recovered, and the effective ingredient p-chlorobenzaldehyde therein is converted into p-chlorobenzoic acid simultaneously, reducing wastewater treatment pressure, reducing pollution to the environment, and avoiding waste of materials.

The application provides a preparation method of bumetanide, taking p-chlorobenzoic acid as a starting material, performing chlorosulfonation, nitration, and ammonolysis to obtain a key intermediate of 3-(N-(tert-butyl) sulfamoyl)-4-chloro-5-nitrobenzoic acid, then performing phenoxylation, nitro reduction, n-butylation, and tert-butyl removal, and finally obtaining the bumetanide. Compared with the synthesis process of the prior art, the method has less side reactions, low cost, high yield, high safety, and is beneficial to industrial production.

The invention relates to the fields of chemistry and chemical engineering, organic synthesis and medicinal chemistry, in particular to a method for synthesizing 5-bromo-2-chlorobenzoic acid by adopting a microchannel reaction device. The method comprises the following steps: I, mixing 2-chlorobenzoic acid and sulfuric acid to obtain a reaction solution A; mixing bromine, sodium periodate, liquid organic acid and water to obtain a reaction solution B; and II, feeding the reaction liquid A and the reaction liquid B into a micro mixer of a micro-channel reaction device for mixing, then feeding the mixture into a micro reactor of the micro-channel reaction device for contact reaction, and carrying out post-treatment on contact reaction effluent to obtain the 5-bromo-2-chlorobenzoic acid. The method has the advantages of high product selectivity, high yield, high purity, convenient process, low production cost, and less by-product and three-waste pollution.

The invention provides a system for separating p-chlorobenzaldehyde and p-chlorobenzoic acid. The system comprises a crystallization tank, a circulating material tank, a desublimation tank, a temperature control device and a finished product tank. A plurality of coil pipes are arranged in the crystallization tank, the outer wall is wrapped by a jacket, and the top and the bottom are respectively provided with an upper air inlet and a lower air inlet; a plurality of devitrification plates are arranged in the desublimation tank, and a discharge port is formed in the bottom; and the temperature control device is used for regulating and controlling the temperatures of the coil pipe, the jacket and the devitrification disc. Based on the system, the p-chlorobenzoic acid is crystallized from p-chlorobenzaldehyde at a proper temperature by utilizing the solidification and sublimation characteristics of p-chlorobenzaldehyde and p-chlorobenzoic acid, then the p-chlorobenzoic acid is sublimated to the desublimation tank for desublimation by heating according to the sublimation characteristic of p-chlorobenzoic acid, and the two materials are separated in such a manner, so that the quality of p-chlorobenzoic acid is improved, and the quality of p-chlorobenzoic acid is improved. The purity of p-chlorobenzaldehyde is improved, the purity of p-chlorobenzoic acid is high after separation, no water or other solvents are added, no other hazardous waste is generated, operation is easy and convenient, and the purpose of clean production is achieved.

The invention relates to the technical field of organic synthesis, and provides a method for preparing o-sulfonyl chloride / amine methyl benzoate by using o-chloromethyl benzoate. The preparation method comprises the following steps: 1, mixing methyl o-chlorobenzoate and pure water, stirring, adding sodium thiosulfate, and heating for reaction to obtain a solution; the preparation method comprises the following steps: adding dichloroethane and pure water into a reaction kettle, stirring, cooling, introducing chlorine, dropwise adding a solution, controlling the dropwise adding time and the temperature of the reaction kettle, carrying out a heat preservation reaction, removing chlorine, and drying to obtain o-sulfonyl chloride methyl benzoate; and 2, on the basis of the prepared o-sulfonyl chloride methyl benzoate, adding the o-sulfonyl chloride methyl benzoate into methanol while stirring, cooling, adding an ammonia solution, heating for reaction to generate a crude o-sulfonamide methyl benzoate product, and adding an adsorbent for purification to obtain the o-sulfonamide methyl benzoate. The preparation method disclosed by the invention is relatively low in production cost, less in waste gas and waste water and capable of realizing coordinated development of economic benefits and environmental benefits, and the o-sulfonyl chloride / methyl aminobenzoate is high in purity.

The invention discloses a synthetic method of cyantraniliprole, and belongs to the technical field of production of cyantraniliprole, and the synthetic method comprises the following steps: step 1, taking o-chlorobenzoic anhydride as an initial raw material, and adding the o-chlorobenzoic anhydride and other raw materials into synthesis equipment; step 2, firstly carrying out amidation reaction on the ester group at the 1-position of the benzene ring and amino to generate an intermediate product, then carrying out amidation reaction on the ester group at the 2-position of the benzene ring, and using 2-amino-2-methylpropionitrile as a reactant; 3, after the two amidation reactions are completed, post-treatment is conducted, a product is purified and crystallized, and finally the cyantraniliprole product is obtained. The raw materials can be slowly pushed in batches, a large amount of raw materials are prevented from entering the reaction cylinder in a concentrated mode, the raw materials are ground before being added, the caked raw materials are prevented from directly entering the reaction cylinder, and efficient reaction is facilitated.

The invention provides a preparation method of furosemide, which comprises the following specific steps: (1) adding 2-amino-4-chlorobenzoic acid and 2-chloromethyl furan into a deep eutectic solvent, and carrying out microwave heating reaction to obtain a reaction solution; and (2) sequentially adding chlorosulfonic acid and thionyl chloride into the reaction liquid to react, adding ammonia water, and then performing supercritical CO2 fluid extraction to obtain furosemide. The synthetic method of the furosemide is simple, efficient and low in energy consumption, unnecessary side reactions can be avoided, extra impurities are not generated, post-treatment mother liquor does not exist, the synthesized furosemide is high in yield and purity, and the synthetic method is suitable for large-scale actual production. According to the method, the deep eutectic solvent is selected as a novel solvent, and compared with a single solvent, the deep eutectic solvent can improve the reaction rate and the product yield and can reduce environmental pollution.

The invention provides a preparation method of a 2-amino-3-methyl-5-chloro-benzoic acid compound, which comprises the following synthesis route: wherein the definitions of R1 and R2 are the same as those in the specification.

The invention discloses a continuous synthesis method of 1-(2-chlorphenyl)-2-(2-tetrazolyl) ethanone, which comprises the following steps: (1) introducing a trimethylsilylated diazomethane solution and a strong alkali solution into a micro-channel reactor 1 for reaction, introducing the obtained intermediate reaction solution and a 2-chloromethyl benzoate solution into a micro-channel reactor 2 for continuous reaction, the preparation method comprises the following steps: adding 2-chlorophenyl to generate 1-(2-chlorophenyl)-2-(2-tetrazolyl-trimethylsilane) ethanone; and (2) removing a TMS group from the 1-(2-chlorphenyl)-2-(2-tetrazolyl-trimethylsilane) ethanone, and then carrying out post-treatment to obtain the 1-(2-chlorphenyl)-2-(2-tetrazolyl) ethanone. The continuous synthesis method uses a fluid process, has the advantages of small amplification effect, high production efficiency and environmental protection, improves the selectivity of 2-tetrazole, and avoids partial sensitization of intermediates.

The invention provides a preparation method of 2-chloro-6-mercaptobenzoic acid. The 2-chloro-6-mercaptobenzoic acid is used as a raw material. Comprising the following steps: in a protective gas atmosphere, mixing a bivalent palladium catalyst, a phosphine ligand, an alcohol solvent and an aromatic solvent, and adding water for pre-activation to obtain a reaction solution; and in a protective gas atmosphere, mixing the reaction liquid, a compound 2, 6-dichlorobenzoic acid, a vulcanizing reagent and inorganic alkali, performing vulcanization reaction, and adding reducing metal and acid for reaction to obtain the 2-chloro-6-mercaptobenzoic acid. The preparation method provided by the invention is simple and convenient to operate and high in yield, and can be amplified to industrial production.

The application belongs to the technical field of medical intermediates, and relates to a production method of a clotrimazole intermediate (2-chlorophenyl)diphenylmethanol. In the method, 2-methyltetrahydrofuran or cyclopentyl methyl ether is used as a reaction solvent, an ethyl o-chlorobenzoate solution is added dropwise into a phenyl magnesium bromide solution with a concentration of 2.5-3.5 M under the conditions of 60-80 DEG C and inert atmosphere, the reaction is continuously carried out after the dropwise addition is completed, a water solution of a quenching agent is added after the reaction to quench, then, liquid separation is carried out, and the organic phase after the liquid separation is concentrated to obtain a crude product; the crude product is refined by using a reaction solvent and petroleum ether, and (2-chlorophenyl)diphenylmethanol is obtained. The production method can efficiently and stably produce high-quality (2-chlorophenyl)diphenylmethanol, reduces production cost and safety hazards, and can be used for large-scale industrial production.

The invention provides a novel N / P co-coordinated Co-Mn bimetallic monatomic catalytic ozonation water quality purification method, which comprises the following steps: mixing an N / P co-coordinated Co-Mn bimetallic monatomic catalyst with water to be treated, and carrying out ozone aeration, the N / P co-coordinated Co-Mn bimetal monatomic catalyst comprises a carrier and active sites loaded on the carrier, wherein the active sites comprise N / P co-coordinated Co-Mn bimetal monatomic sites. According to the method, rapid removal of various refractory organic micropollutants, such as acetaminophen, sulfamethoxazole, parachlorobenzoic acid and nitrobenzene, can be realized, and the retention time of the reaction can be reduced while the dosage of the ozone catalyst is reduced.

The invention belongs to the technical field of polyurethane, and provides a coal mine reinforcing polyurethane material and a preparation method thereof, the coal mine reinforcing polyurethane material comprises a component A and a component B according to a mass ratio of 0.8-1.2: 1; the component A is prepared from 70 to 90 parts of polyether polyol A, 10 to 30 parts of polyether polyol B, 0.1 to 3.0 parts of a catalyst, 10 to 40 parts of a flame retardant, 1 to 20 parts of a cross-linking agent and 0.5 to 3 parts of fumed silica; the component B comprises the following components in parts by weight: 100-140 parts of an isocyanate prepolymer, 10-30 parts of a flame retardant and 5-20 parts of a toughening agent; the cross-linking agent is selected from one or more of 3-chloro-4, 4 '-diaminodiphenylmethane, 3, 5-diamino-4-chlorobenzoic acid isobutyl ester and 4, 4'-methylenebis (2-methyl-6-diethylaniline), and the cross-linking agent is selected from one or more of 3-chloro-4, 4 '-diaminodiphenylmethane, 3, 5-diamino-4-chlorobenzoic acid isobutyl ester and 4, 4'-methylenebis (2-methyl-6-diethylaniline); the preparation method comprises the following steps: mixing 5-30 parts of polyether polyol C and 70-120 parts of polyphenyl polymethylene polyisocyanate, and keeping the temperature at 70-90 DEG C for 3-5 hours to prepare an isocyanate prepolymer. The highest reaction temperature of the polyurethane material is less than or equal to 100 DEG C, the compressive strength is more than or equal to 60MPa, and the polyurethane material has a wide application prospect in the field of coal and rock mass reinforcement.

The invention discloses a method for preparing an S-isomer of montelukast sodium, which belongs to the technical field of chemical raw material medicines, and is characterized by comprising the following steps: dissolving a starting material montelukast sodium mother nucleus in an organic solvent, and carrying out configuration inversion under the action of an initiator and the catalysis of a composite catalyst to generate the S-isomer of the montelukast sodium mother nucleus; and adding 1-mercaptomethyl cyclopropyl acetic acid, reacting under the catalysis of a catalyst, filtering, cooling, growing crystal, carrying out suction filtration and drying to obtain the montelukast S-isomer. The preparation method has the beneficial effects that azodiisobutyronitrile is creatively used as an initiator, and under the catalysis of a composite catalyst tributylphosphine and m-chlorobenzoic acid, a montelukast mother nucleus is subjected to an isomerization reaction to obtain a montelukast mother nucleus S-isomer; and reacting with 1-mercaptomethyl cyclopropyl acetic acid under the catalysis of H < + >-montmorillonite to obtain the S-isomer of montelukast sodium.

The invention relates to 3-hydroxy-2, 4-dichloroacetophenone prepared by a one-pot method and a preparation method of the 3-hydroxy-2, 4-dichloroacetophenone, and belongs to the technical field of organic synthesis. The 3-hydroxy-2, 4-dichloroacetophenone prepared by the one-pot method is prepared from the following raw materials: ethyl 3-hydroxy-2, 4-dichlorobenzoate, an organic solvent, a catalyst and a photosensitizer. The preparation method of the 3-hydroxy-2, 4-dichlorobenzoic acid ethyl ester comprises the following steps: corn bran extraction, acidification, chlorination, reflux, extraction and evaporation. The 3-hydroxy-2, 4-dichlorobenzoic acid ethyl ester containing a benzene ring is introduced into a reaction route disclosed by the invention, the 3-hydroxy-2, 4-dichloroacetophenone is obtained through a Fries light rearrangement reaction route, an acyl compound can be specifically generated on an aromatic ring without influencing other functional groups, and the method has the characteristics of simple operation and mild reaction conditions. The 3-hydroxy-2, 4-dichlorobenzoic acid ethyl ester is a byproduct corn bran from corn processing, and has the characteristics of high additional value utilization and environmental friendliness.

The invention relates to application of m-chlorobenzoic acid in promoting growth of panax notoginseng and preventing and treating diseases. It is found that m-chlorobenzoic acid has a good pseudo-ginseng fusarium and rust rot fungus inhibiting effect, and therefore m-chlorobenzoic acid can be used for preventing and treating pseudo-ginseng root rot. In addition, the invention also finds that m-chlorobenzoic acid can promote the growth of beneficial bacteria such as trichoderma and penicillium. Therefore, after the metachlorobenzoic acid is applied to the panax notoginseng, the metachlorobenzoic acid can promote seedling storage of annual panax notoginseng, increase the dry weight of single plants of the overground part and the underground part of the panax notoginseng and promote growth of fibrous roots of the panax notoginseng.

The invention relates to the technical field of o-chlorobenzoic acid preparation, in particular to a method for preparing o-chlorobenzoic acid through electrochemical selective debromination. The method comprises the following steps: (1) taking a sulfuric acid aqueous solution as anolyte and a sodium hydroxide aqueous solution as catholyte; adding a reaction raw material chlorobromobenzoic acid into the cathode liquor, uniformly mixing, and carrying out electrolytic debromination; (2) adjusting the pH value of the reacted catholyte to be acidic, separating to obtain a solid and an acid solution, and washing and drying the solid to obtain a white filter cake, namely o-chlorobenzoic acid; and (3) carrying out electrodialysis dissociation on the obtained acid liquor to respectively obtain sodium hydroxide and recovered acid liquor. According to the method, chlorobromobenzoic acid is adopted as a raw material to carry out electrochemical selective debromination to prepare o-chlorobenzoic acid, and the raw material chlorobromobenzoic acid is only debrominated but not dechlorinated through accurate control of electrodes, electrolyte and electrolysis conditions.

The invention provides a preparation method of 4-chloro-6, 7-dihydro-5H-cyclopenta [B] pyridine-7-alcohol, and relates to the technical field of organic synthesis. A compound 1 and first m-chloroperoxybenzoic acid are subjected to a first oxidation reaction to obtain a compound 2 crude product, the compound 2 crude product and acid anhydride are directly subjected to a Boekelhede reaction to obtain a compound 3, the water solubility of the compound 3 is poor, the compound 3 is easily separated from a water-soluble byproduct m-chlorobenzoic acid, and a large amount of loss of the compound 3 in the subsequent separation process cannot be caused; the yield of the compound 3 is improved; and carrying out a second oxidation reaction on the compound 3 and second m-chloroperoxybenzoic acid, carrying out a chlorination reaction on the obtained compound 4 and phosphorus oxychloride, and carrying out a hydrolysis reaction on the obtained compound 5 to obtain the 4-chloro-6, 7-dihydro-5H-cyclopenta [B] pyridine-7-ol. According to the preparation method provided by the invention, the total yield of the 4-chloro-6, 7-dihydro-5H-cyclopenta [B] pyridine-7-alcohol is high.

The application discloses a synthesis process of chlorobenzoic acid, and the NiMo-Sb2O3 / TiO2-CeO2-MgO composite catalyst prepared by the method can better prepare ortho-chlorotoluene, has high selectivity and long service life, and has mild process conditions and small carbon deposition amount, so that the application has important significance for improving product quality, reducing production cost and promoting green development of the industry.

The present invention discloses the preparation and application of a cannabinoid monoclonal antibody, belonging to the field of biotechnology. The specific steps for the preparation of the cannabinoid monoclonal antibody include: (1) hapten preparation: reacting a cannabinoid molecule with methyl 4-chlorobenzoate to obtain the hapten; (2) complete antigen preparation: coupling the hapten with hemocyanin to obtain the complete antigen. The present invention prepares the complete antigens of tetrahydrocannabinol, cannabigerol or cannabidiol, further prepares the corresponding monoclonal antibodies, and then uses the prepared monoclonal antibodies to prepare a colloidal gold test strip. The prepared colloidal gold test strip has strong specificity and high sensitivity. The complete antigen is obtained by coupling a tetrahydrocannabinol, cannabigerol or cannabidiol molecule with hemocyanin.