209995-38-0Relevant articles and documents
Novel preparation method of 2, 4, 5-trifluorophenylacetic acid
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Paragraph 0037; 0075; 0088-0089; 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.
Preparation method of 2, 4, 5-trifluorophenylacetic acid
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Paragraph 0065-0067; 0069-0070, (2021/07/28)
The invention provides a preparation method of 2, 4, 5-trifluorophenylacetic acid. The method comprises the following steps: 1) reacting 2, 4, 5-trifluorobromobenzene with metal magnesium to obtain 2, 4, 5-trifluorophenyl magnesium bromide; 2) reacting 2, 4, 5-trifluorophenyl magnesium bromide with halogenated acetate to prepare an intermediate A; 3) hydrolyzing the intermediate A in an alkaline solution or an acidic solution to obtain 2, 4, 5-trifluorophenylacetic acid. The structure of the intermediate A is shown as the following structure, wherein R represents a C1-C10 alkyl group. The preparation method of 2, 4, 5-trifluorophenylacetic acid provided by the invention has the advantages of simple process flow, low cost, environmental friendliness and mild conditions.
Hydrogen Bond Directed Photocatalytic Hydrodefluorination and Methods of Use Thereof
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Paragraph 0138, (2021/01/22)
Methods of synthesizing compounds comprising fluorinated aryl groups are disclosed, wherein said methods utilize hydrogen bond directed photocatalytic hydrodefluorination.