327-52-6Relevant articles and documents
Novel preparation method of 2, 4, 5-trifluorophenylacetic acid
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Paragraph 0037; 0075; 0086-0087; 0097-0100; 0102-0103; ..., (2021/06/23)
The invention discloses a novel preparation method of 2, 4, 5-trifluorophenylacetic acid, which belongs to the technical field of preparation of medical intermediates, and comprises the following preparation steps: carrying out nitration reaction on sulfuric acid and m-dichlorobenzene to obtain an intermediate II; adding the intermediate II, a phase transfer catalyst and potassium fluoride into an aprotic solvent to obtain an intermediate III; performing hydrogenation reaction on the intermediate III to obtain an intermediate IV; carrying out diazotization reaction on the intermediate IV, nitrosyl sulfuric acid and sodium fluoborate to obtain an intermediate V; performing cracking reaction on the intermediate V to obtain an intermediate VI; carrying out reduction reaction on the intermediate VI, and then carrying out bromination reaction on the intermediate VI and liquid bromine to obtain an intermediate VII; subjecting the intermediate VII to a substitution reaction with diethyl malonate, and obtaining 2, 4, 5-trifluorophenylacetic acid after hydrolysis and purification. A novel synthesis route is provided, the problem that technological operation is tedious is solved, the requirements for reaction and operation conditions are low, anhydrous and oxygen-free reaction conditions are not needed, the method is suitable for industrial production, and the yield and purity are greatly improved.
Efficient preparation method of 2, 4, 5-trifluorophenylacetic acid
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Paragraph 0015; 0016; 0017; 0018, (2018/03/26)
The invention discloses an efficient preparation method of 2, 4, 5-trifluorophenylacetic acid and belongs to the technical field of synthesis of a pharmaceutical intermediate. The preparation method comprises synthesis of 2, 3, 5-trifluoroaniline, synthesis of 1, 2, 4-trifluorobenzene, synthesis of trifluorobromobenzene and synthesis of a desired product 2, 4, 5-trifluorophenylacetic acid. The preparation method is simple and easy to operate, utilizes cheap and easily available raw materials and has high reaction efficiency and good repeatability.
PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
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Paragraph 00139, (2017/07/28)
The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.