13 results about "O-chloronitrobenzene" patented technology

The invention discloses a synthesis method of 2, 4, 5-trifluorophenylacetic acid, which comprises the following steps: by taking cheap and easily available o-chloronitrobenzene as a raw material, reacting with sodium nitrate in a sulfuric acid and trifluoroacetic acid system, separating generated 2, 4-dinitrochlorobenzene through melt crystallization, and continuing to synthesize 2, 4-dinitrochlorobenzene in methyl chloroacetate to obtain 2, 4, 5-trifluorophenylacetic acid. The method comprises the following steps: carrying out indirect aromatic nucleophilic substitution reaction on 2, 4-dinitrophenylacetic acid under the condition of sodium hydride to generate 5-chloro-2, 4-dinitrophenylacetic acid methyl ester, separating, carrying out fluorination reaction on the 5-chloro-2, 4-dinitrophenylacetic acid methyl ester and potassium fluoride under the action of a phase transfer catalyst, carrying out rectification separation to obtain 2, 4, 5-trifluorophenylacetic acid, and carrying out hydrolytic acidification on the 2, 4, 5-trifluorophenylacetic acid in a sodium hydroxide aqueous solution to obtain 2, 4, 5-trifluorophenylacetic acid. And the process route is safer, more environment-friendly, more efficient and lower in cost.

The invention discloses a nitrogen-doped carbon-coated catalyst and a preparation method and application thereof, and the preparation method of the nitrogen-doped carbon-coated catalyst comprises the following steps: 1, dissolving anhydrous zinc chloride in a solvent, and adjusting the pH value of the mixed solution to 9.5-11.5; adding 1H-1, 2, 3-triazole, and stirring at room temperature, so as to obtain an MET-Zn precursor; 2, respectively dissolving the MET-Zn precursor and Fe, Co or Ni metal nitrate in a solvent, then mixing the two solutions, and carrying out ion exchange under the protection of nitrogen to obtain an M-MET precursor subjected to ion exchange; and 3, carbonizing the M-MET precursor subjected to ion exchange in an inert atmosphere to obtain the nitrogen-doped carbon-coated catalyst. The invention provides an application of the nitrogen-doped carbon-coated catalyst in a liquid-phase catalytic hydrogenation reaction of o-chloronitrobenzene. The nitrogen-doped carbon-coated catalyst has the characteristics of high catalytic activity, selectivity and stability and capability of being magnetically recycled.

The invention relates to a one-pot synthesis method of a fluxapyroxad intermediate 3 ', 4', 5 '-trifluoro-2-nitrobiphenyl, and belongs to the technical field of organic synthesis.The method comprises the following steps that 1, under nitrogen protection, magnesium chips, a catalyst and a solvent are added into a reaction flask, then a mixed solution of 3, 4, 5-trifluorobromobenzene, o-chloronitrobenzene and boric acid ester is dropwise added, a reaction is conducted for 1-2 h, and a reaction solution is obtained; after dropwise adding, carrying out heat-preservation reaction; 2, after the reaction is finished, 10% diluted hydrochloric acid is added for acidification and water washing, after phase splitting, an obtained organic phase is subjected to vacuum concentration, and 3 ', 4', 5 '-trifluoro-2-nitrobiphenyl is obtained. Compared with a traditional synthesis method of the fluxapyroxad intermediate, the synthesis method of the fluxapyroxad intermediate has the advantages that 3, 4, 5-trifluorophenylboronic acid does not need to be prepared firstly, 3, 4, 5-trifluorobromobenzene and o-chloronitrobenzene are directly used as raw materials, the one-pot synthesis method is short in reaction route and high in raw material utilization rate, and the raw material cost can be greatly reduced.

The present invention relates to a one-pot synthesis method of the fluxapyroxad intermediate 3',4',5'-trifluoro-2-nitrobiphenyl, belonging to the technical field of organic synthesis. The method process includes the following steps: Step 1: Under nitrogen protection, add magnesium chips, a catalyst and a solvent to a reaction flask, and then dropwise add a mixed solution of 3,4,5-trifluorobromobenzene, o-chloronitrobenzene and borate ester. After the dropping is completed, keep the reaction under heat preservation; Step 2: After the reaction is completed, acidify and wash with 10% dilute hydrochloric acid, and after phase separation, the obtained organic phase is concentrated under reduced pressure to obtain 3',4',5'-trifluoro-2-nitrobiphenyl. In the present invention, compared with the traditional synthesis method of the fluxapyroxad intermediate, the synthesis method of the present fluxapyroxad intermediate does not need to prepare 3,4,5-trifluorophenylboronic acid first, but directly uses 3,4,5-trifluorobromobenzene and o-chloronitrobenzene as raw materials. The "one-pot" synthesis method has a short reaction route, high raw material utilization rate, and can greatly reduce the raw material cost.

The invention relates to a preparation method of 2, 5-disulfonic acid aniline sodium salt, which comprises the following steps: heating and melting o-chloronitrobenzene in a reaction device, and dropwise adding sulfur trioxide; heating and sulfonating twice, and keeping the temperature to the sulfonation end point; dropwise adding the sulfonated product into water for dilution, adding activated carbon for decoloration, and filtering to obtain sulfonated diluent; adding alkali liquor into the sulfonation diluent, adjusting the pH value of the system, then adding sulfite, and heating, refluxing, replacing and sulfonating to the end point; adjusting the system to be neutral with acid; oxidation pretreatment: dropwise adding an oxidant into a neutral reaction system, and carrying out heat preservation reaction to an oxidation end point; catalytic hydrogenation: adding a noble metal catalyst into a reaction system, introducing hydrogen, and carrying out catalytic hydrogenation; and adding inorganic salt for salting out, cooling, preserving heat, growing crystals, separating out, filtering and drying to obtain a finished product. Through an integrated route of SO3 sulfonation, oxidation pretreatment and catalytic hydrogenation, one-pot method continuous operation can be performed under mild conditions, the product purity is greater than or equal to 99%, the yield is greater than or equal to 90%, and the catalyst can be stably and mechanically applied for more than 20 times.

The application discloses a nitrogen-doped carbon-coated catalyst and a preparation method and application thereof. The preparation method of the nitrogen-doped carbon-coated catalyst is carried out according to the following steps: step one: dissolving anhydrous zinc chloride in a solvent, and then adjusting the pH of the mixed solution to 9.5-11.5; adding 1H-1,2,3-triazole and stirring at room temperature to obtain a MET-Zn precursor; step two: dissolving the MET-Zn precursor and Fe, Co or Ni metal nitrate in solvents respectively, then mixing the two solutions, and carrying out ion exchange under nitrogen protection to obtain an ion-exchanged M-MET precursor; and step three: carbonizing the ion-exchanged M-MET precursor under an inert atmosphere to obtain the nitrogen-doped carbon-coated catalyst. The application provides application of the nitrogen-doped carbon-coated catalyst in a liquid-phase catalytic hydrogenation reaction of o-chloronitrobenzene, and the nitrogen-doped carbon-coated catalyst has the characteristics of high catalytic activity, selectivity and stability and can be magnetically recovered.

This invention belongs to the field of fine chemical technology, specifically relating to a process for the hydrogenation of o-chloronitrobenzene to o-chloroaniline. The process includes the following steps: o-chloronitrobenzene reacts with hydrogen in the presence of a Pd / N,B-C catalyst to obtain o-chloroaniline; the Pd / N,B-C catalyst comprises an N,B co-doped carbon support and a Pd active component supported on the support. This invention utilizes a Pd / N,B-C catalyst combined with a solvent-free preparation process to achieve a highly efficient and selective conversion of o-chloronitrobenzene to o-chloroaniline.

The present application belongs to the field of organic chemistry, and particularly relates to a green preparation method of 4'-chloro-2-nitrobiphenyl. The present application uses o-chloronitrobenzene and 4-chlorophenylboronic acid as raw materials, and synthesizes high-purity 4'-chloro-2-nitrobiphenyl through a Suzuki-Miyaura cross-coupling reaction. The process uses a low-palladium catalyst system, di-tert-butylphenyl phosphine as a ligand, and sodium bicarbonate as a base, and the whole process uses water as a green reaction medium, without using toxic and harmful organic solvents. The cross-coupling reaction can be successfully completed under mild conditions, and the reaction has good selectivity and high conversion efficiency. Compared with the traditional synthesis process, the preparation method has multiple advantages: the overall reaction operation is simple and easy to implement, the procurement channel of the core raw material is smooth, the cost is controllable, the water-phase reaction system has little environmental pollution, the yield of the target product is excellent, the product purity is high, the quality is stable and controllable, the overall process safety is high, the repeatability is high, and the process completely has the feasibility and popularization value of industrial large-scale production.

The application provides a method for preparing 2-nitro diphenyl compounds, comprising the following steps: reacting phenylboronic acid or phenylboronic ester compounds with o-chloronitrobenzene compounds in the presence of a catalyst in an oxygen-free environment to obtain 2-nitro diphenyl compounds; the catalyst is a complex formed by a noble metal or a salt thereof and a ligand; and the ligand is a ferrocene compound with a tert-butyl phosphine group. In the preparation method, the ligand molecule used does not have a benzene ring, and in the case of a lower dosage of the noble metal salt and the ligand, the reaction can be efficiently catalyzed in an oxygen-free environment, the reaction yield is high, and in the preparation method, a self-polyoxyethylene type or a polyhydric alcohol type non-ionic surfactant does not need to be added, the preparation method is simple and efficient, and is suitable for industrial production.

The invention discloses a preparation method of 3 ', 4', 5 '-trifluoro-2-nitrobiphenyl, which comprises the following steps: reacting 3, 4, 5-trifluorophenylboronic acid or 3, 4, 5-phenylboronic acid ester compounds with o-chloronitrobenzene in the presence of an organic solvent-water system, an acid-binding agent and a complex to obtain 3', 4 ', 5'-trifluoro-2-nitrobiphenyl, and reacting 3, 4, 5-trifluorophenylboronic acid or 3, 4, 5-phenylboronic acid ester compounds with o-chloronitrobenzene to obtain 3 ', 4', 5 '-trifluoro-2-nitrobiphenyl. The complex is prepared from a palladium salt and an alkyl-4-alkyl amino phenyl phosphine compound. According to the preparation method, by optimizing the type of the complex, under the combined action of an organic solvent-water system, the acid-binding agent and the complex, the sensitivity of the complex to oxygen can be reduced while the dosage of the catalyst is small, then raw materials can be efficiently catalyzed to generate the Suzuki coupling reaction, the product with high yield and high content is obtained, and the method is suitable for industrial production. The method has the advantages of simple process, simple operation, cheap and easily available raw materials, low cost and the like, cannot cause production limitation due to raw material problems, and is beneficial to industrial production.

The utility model provides a device for producing o-fluoronitrobenzene and recovering a catalyst. The device comprises a reaction kettle, a cooling kettle, a plate-and-frame filter, a rectifying tower and a finished product storage tank which are communicated, the reaction kettle is communicated with a DMF (Dimethyl Formamide) metering tank, an o-chloronitrobenzene metering tank and a potassium fluoride metering tank, and the reaction kettle is also provided with a catalyst adding port; a gas outlet of the reaction kettle is communicated with the first condenser through a reflux pipeline, and a liquid outlet of the first condenser is communicated with the reaction kettle; a gas outlet of the first condenser is sequentially communicated with an alkali spray tower and a water spray tower; a solid outlet of the plate-and-frame filter is communicated with the drying tank and the catalyst recovery tank; a filtrate outlet of the plate-and-frame filter communicates with the rectifying tower; a gas outlet of the rectifying tower is communicated with a solvent recovery tank and a finished product storage tank through a second condenser. According to the device, the catalyst in the reaction process can be recycled, the solvent can be recycled, tail gas generated in the production process is effectively treated, and the whole process is more environment-friendly.

The invention discloses an ultralow-impurity mercaptobenzothiazole rubber accelerator and a preparation method thereof in the technical field of rubber assistants, and the method comprises the following steps: taking o-chloronitrobenzene, carbon disulfide and sulfur as raw materials, and carrying out cyclization reaction at high temperature in the presence of a specific catalyst to generate mercaptobenzothiazole sodium salt; the method is characterized in that two newly designed modified compounds are added step by step in the reaction process, firstly, a benzothiazole derivative which is used as a crystallization regulating agent and contains thioether bonds and carboxyl is added, and then, a symmetric bis-benzothiazolyl urea derivative which is used as an impurity trapping agent is added; and after acidification and crystallization, purifying through solvent recrystallization and activated carbon decoloration. The two modified compounds effectively control the crystallization process and selectively remove impurities through intermolecular interaction, and finally a mercaptobenzothiazole product with extremely high purity is prepared. The accelerator is extremely low in impurity content, shows excellent scorching resistance and vulcanization efficiency in the rubber vulcanization process, and is suitable for production of high-performance rubber products.

The invention belongs to the technical field of catalytic hydrogenation, and particularly relates to a preparation method and application of a mercaptan-modified carbon-coated nickel catalyst. The preparation method of the catalyst comprises the following steps: uniformly mixing nickel nitrate and citric acid according to a molar ratio of 1: (1-3) to obtain a precursor; completely pyrolyzing the precursor in a nitrogen atmosphere at the temperature of 400-650 DEG C to obtain a carbon-coated nickel Ni-C catalyst; soaking in a mercaptan-ethanol solution, carrying out hydrothermal reaction at 80-140 DEG C for 3-24 hours, and carrying out mercaptan modification, so as to obtain a mercaptan modified carbon-coated nickel catalyst; the mercaptan-modified carbon-coated nickel catalyst is applied to selective hydrogenation of o-chloronitrobenzene to obtain o-chloroaniline, long-reaction-time experiments prove that the mercaptan-modified carbon-coated nickel catalyst can completely selectively hydrogenate o-chloronitrobenzene into a target product o-chloroaniline without generating a by-product aniline, and the conversion rate of the mercaptan-modified carbon-coated nickel catalyst can be ensured in short reaction time; the catalyst is stable in structure, can be recycled for reaction, and is simple in synthesis process, easy to repeat, high in operability and beneficial to large-scale production.