31881-89-7Relevant academic research and scientific papers
Synthesis method of 3, 5-difluorophenol
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Paragraph 0082-0089, (2021/04/07)
The invention discloses a synthetic method of 3, 5-difluorophenol, and belongs to the technical field of chemical synthesis. According to the method, 3,5-difluorophenolate is obtained through a one-pot reaction of 2,4,6-trifluorobenzoic acid in a solvent under the action of alkali, 3,5-difluorophenol is obtained after acid regulation and dissociation, and the method has the advantages of cheap and easily available raw materials, short synthesis steps, simple operation, mild reaction conditions, high synthesis yield, good product quality, suitability for industrial production and the like. According to the method, cheap and easily available pentachloronitrile is taken as a raw material, 2, 4, 6-trifluoro-3, 5-dichlorobenzonitrile is obtained through a fluorination reaction, 2, 4, 6-trifluoro-3, 5-dichlorobenzoic acid is obtained through a hydrolysis reaction, and finally, the raw material 2, 4, 6-trifluoro-3, 5-dichlorobenzoic acid is synthesized through a selective dechlorination reaction, so that simple, cheap and efficient preparation of the raw material 2, 4, 6-trifluorobenzoic acid is realized, and the industrial application value of the synthesis process is improved.
Preparation method of compound 2,4,6-trifluorobenzylamine
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Paragraph 0024; 0031; 0032, (2021/03/11)
The invention discloses a preparation method of a compound 2,4,6-trifluorobenzylamine, and relates to the field of organic synthesis. According to the preparation method, pentachlorobenzonitrile is used as a starting raw material and is subjected to a fluorination reaction with a fluorinating agent in an organic solvent under the action of a catalyst to obtain 3,5-dichloro-2,4,6-trifluorobenzonitrile. The obtained 3,5-dichloro-2,4,6-trifluorobenzonitrile is added into water and reacts with zinc powder and mixed acid, and then reflux dechlorination is performed to obtain 2,4,6-trifluorobenzonitrile. The obtained 2,4,6-trifluorobenzonitrile is added into an organic solvent, and hydrogenation reduction is carried out under the action of an organic alkali and a catalyst to obtain the product 2,4,6-trifluorobenzylamine. The method has the advantages of short synthesis route, simple operation, mild reaction conditions, cheap and easily available raw materials and stable product quality, andis suitable for large-scale industrial production.
PROCESS FOR PREPARATION OF 2,4,6-TRIFLUOROBENZOIC ACID
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Page/Page column 9, (2021/08/14)
The present invention provides a process for the preparation of 2,4,6-trifluorobenzoic acid, having less than 0.05% of 2,6-difluorobenzoic acid and/or 2,4-difluorobenzoic acid impurities. The 2,4,6-trifluorobenzoic acid is crucial and an important raw material for preparing the photosensitizers, medicines and pesticides, and also finds applications in pharmaceutical and agrochemical industries.
SYNTHESIS METHOD OF 2,4,6-TRIFLUOROBENZYLAMINE
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Paragraph 0043-0051; 0073-0075, (2020/07/16)
The disclosure provides a synthesis method of 2,4,6-trifluorobenzylamine, belonging to the technical field of chemical synthesis. The synthesis method is characterized by comprising the following steps: (1) allowing pentachlorobenzonitrile as a raw material to undergo fluoridation reaction with a fluoridation agent based on 2,4,6-trifluoro-3,5-dichlorobenzonitrile as a solvent to obtain 2,4,6-trifluoro-3,5-dichlorobenzonitrile; (2) hydrogenating the obtained 2,4,6-trifluoro-3,5-dichlorobenzonitrile with hydrogen in the presence of organic carboxylic acid, based, on palladium carbon as a catalyst to obtain 2,4,6-trifluoro-3,5-dichlorobenzylamine; and (3) hydrogenating the obtained 2,4,6-trifluoro-3,5-dichlorobenzylamine with hydrogen in a solvent in the presence of a catalyst to obtain 2,4,6-trifluorobenzylamine. The synthesis method has the advantages of low raw material cost, short reaction steps, high reaction yield, good product purity simple operation and the like, and is suitable for industrial production.
Preparation method of 2,4,6-trifluorobenzylamine
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Paragraph 0043; 0045; 0046; 0048; 0050, (2018/03/24)
The invention provides a preparation method of 2,4,6-trifluorobenzylamine. The preparation method comprises the following steps: S1, by taking pentachloro benzonitrile as a starting material, adding the pentachloro benzonitrile into anhydrous potassium fluoride for fluorination reaction in a first organic solvent, thus obtaining 3,5-dichloro-2,4,6-trifluoro-cyanophenyl; S2a, adding the 3,5-dichloro-2,4,6-trifluoro-cyanophenyl prepared in the step S1 into a second organic solvent, adding organic alkali, feeding hydrogen, and carrying out dehydrochlorination reaction under the action of a firstcatalyst, thus obtaining 2,4,6-trifluoro-cyanophenyl serving as an intermediate; S3, adding the 2,4,6-trifluoro-cyanophenyl prepared in the step S2a into a third organic solvent, adding acid, feedinghydrogen, and reducing the 2,4,6-trifluoro-cyanophenyl serving as the intermediate through a cyanogroup under the action of a second catalyst, thus obtaining 2,4,6-trifluorobenzylamine. By the adoption of the technical scheme, the preparation method has the advantages that steps of a synthesis route are simple and short, conditions are mild, operation is simple and convenient, the raw materials are low in cost and readily available, and the production cost is low; the catalysts and solvents can be recycled for use, so that pollution is reduced; the preparation method is environmentally friendly and suitable for industrial large-scale production.
Preparation method of 2,4,6-trifluorobenzylamine
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Paragraph 0020; 0045-0058, (2018/10/11)
The invention discloses a preparation method of 2,4,6-trifluorobenzylamine, and belongs to the technical field of chemical synthesis. The method comprises the following steps: (1), carrying out fluorination reaction on pentachloro benzonitrile and a fluorinating agent in a polar aprotic solvent at the presence of a catalyst so as to obtain 2,4,6-trifluoro-3,5-dichlorobenzonitrile; (2), carrying out hydrogen hydrogenation reduction on 2,4,6-trifluoro-3,5-dichlorobenzonitrile obtained in the step (1) by using palladium charcoal as a catalyst at the presence of organic carboxylic acid so as to obtain 2,4,6-trifluoro-3,5-dichlorobenzylamine; (3) carrying out hydrogen hydrogenation reduction on 2,4,6-trifluoro-3,5-dichlorobenzylamine obtained in the step (2) in the solvent under an effect of the catalyst so as to obtain 2,4,6-trifluorobenzylamine. The preparation method has the advantages of low costs of the raw materials, short reaction steps, high reaction yield, high purity of products and the like, and is suitable for industrial production and application.
METHOD FOR PRODUCING AROMATIC FLUOROCOMPOUND
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Page/Page column 8-9, (2008/06/13)
PROBLEM TO BE SOLVED: To provide a method for producing an aromatic fluorocompound, by which an corresponding aromatic fluorocompound (for example, pentafluorobenzonitrile) can be produced in a high yield by the halogen exchange reaction of an aromatic halogen compound (for example, pentachlorobenzonitrile) with a fluorinating agent (for example, potassium fluoride). SOLUTION: This method for producing the aromatic fluorocompound is characterized by supplying the aromatic halogen compound of raw material as particles having an average particle diameter of 20 to 200μm.
