209995-38-0Relevant articles and documents
Novel preparation method of 2, 4, 5-trifluorophenylacetic acid
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, (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.
Industrial preparation method of 2,4,5-trifluorophenylacetic acid
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, (2021/03/11)
The invention relates to the technical field of preparation of chemical drug intermediates, and particularly discloses an industrial preparation method of 2,4,5-trifluorophenylacetic acid. The preparation method comprises the following steps: carrying out a nitration reaction, a fluorination reaction, a hydrogenation reduction reaction, a diazotization reaction, a halogenation reaction, a cyaniding reaction, a thermal decomposition reaction and a hydrolysis reaction on 2,4-dichlorotoluene to prepare the 2,4,5-trifluorophenylacetic acid. The method has the advantages of low preparation cost andhigh product yield.
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.
Preparation method of 2,4,5-trifluorophenylacetic acid
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, (2021/05/29)
The invention belongs to the technical field of preparation of drug intermediates, and discloses a preparation method of 2,4,5-trifluorophenylacetic acid, wherein the preparation method comprises the steps: step 1, reacting raw materials, a quaternary ammonium salt catalyst, sulfolane and potassium fluoride to obtain a first intermediate; step 2, carrying out hydrogenation catalytic reaction on the first intermediate to obtain a second intermediate; step 3, carrying out salt forming reaction on the second intermediate and a fluorinating reagent, quenching, and carrying out diazotization reaction on the second intermediate and a sodium nitrite aqueous solution to obtain diazonium salt; step 4, carrying out high-temperature cracking on the diazonium salt, to obtain 2,4,5-trifluorotoluene; and step 5 to step 7, carrying out halogenation, cyanidation and hydrolysis reactions on 2,4,5-trifluorotoluene in sequence, and thus obtaining 2,4,5-trifluorophenylacetic acid. The raw materials adopted by the method are easy to obtain and low in cost, the yield of the corresponding product obtained in each step is high, and large-scale production of the 2,4,5-trifluorophenylacetic acid is facilitated.
Synthesis method of 2,4,5-trifluorophenylacetic acid
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Paragraph 0008-0009, (2020/01/12)
The invention discloses a synthesis method of 2,4,5-trifluorophenylacetic acid. 2,4,5-trifluorobromobenzene is used as starting material and condensed with diethyl malonate under the action of magnesium ethylate to obtain 2,4,5-trifluoro-diethyl malonate, 2,4,5-trifluoro-diethyl malonate is hydrolyzed under acidic conditions to obtain 2,4,5-trifluorophenylacetic acid. The invention is simple and easy to operate, the raw materials are cheap and easily available, the total reaction yield is high, and the invention is suitable for industrial production.
Hydrogen Bond Directed Photocatalytic Hydrodefluorination and Methods of Use Thereof
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, (2021/01/22)
Methods of synthesizing compounds comprising fluorinated aryl groups are disclosed, wherein said methods utilize hydrogen bond directed photocatalytic hydrodefluorination.
Preparation method of 2,4,5-trifluorophenylacetic acid
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Paragraph 0025; 0027-0028, (2020/07/21)
The invention provides a preparation method of 2,4,5-trifluorophenylacetic acid. 1,2,4-trifluorobenzene as a raw material and glycolide are catalyzed by a Lewis acid to obtain a final product that issitagliptin intermediate 2,4,5-trifluorophenylacetic acid. The method is mild in reaction condition, and convenient to operate, raw materials are cheap and easily available, steps are simple, and operability is high. High-pressure reaction equipment is not used in the production process, harmful and toxic reagents are not involved, the method has the advantages of being high in safety and environmentally friendly, the obtained 2,4,5-trifluorophenylacetic acid is high in purity, a more valuable synthetic route is provided for preparation of sitagliptin, good social benefits and economic benefits can be brought, and the economic value potential is large.
Synthesis method of sitagliptin intermediate 2,4,5-trifluorophenylacetic acid
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Paragraph 0145-0148, (2020/06/09)
The present invention provides a synthesis method of a sitagliptin intermediate 2,4,5-trifluorophenylacetic acid. The method comprises a substitution reaction, a hydrolysis reaction and a decarboxylation reaction, and specifically comprises: A, carrying out a substitution reaction on a compound 4, or sequentially carrying out a substitution reaction and a hydrolysis reaction to prepare a compoundrepresented by a formula 5; B, carrying out a hydrolysis reaction on the compound represented by the formula 5 to prepare a compound represented by a formula 6; and C, carrying out a decarboxylation reaction on the compound represented by the formula 6 under the catalysis of a catalyst to prepare 2,4,5-trifluorophenylacetic acid, wherein the catalyst is a metal oxide. According to the synthesis process, the 2,4,5-trifluorophenylacetic acid compound is prepared with low cost and high yield, and the industrial scale-up production applicability is high.
Preparation method of 1,3-dicarbonyl compound and intermediate of the 1,3-dicarbonyl compound
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, (2020/05/02)
The invention discloses a preparation method of a 1,3-dicarbonyl compound and an intermediate of the 1,3-dicarbonyl compound, and particularly discloses a preparation method of a compound as shown ina formula I. The preparation method comprises the following step: in a solvent, performing an elimination reaction as shown in the specification on a compound as shown in a formula II to obtain the compound as shown in the formula I, wherein R is a tert-butoxy group, a methoxy group, an ethoxy group or a methyl group. The preparation method disclosed by the invention is relatively low in cost andbeneficial to industrial production.
EFFICIENT PROCESS FOR THE PREPARATION OF SITAGLIPTIN THROUGH A VERY EFFECTIVE PREPARATION OF THE INTERMEDIATE 2,4,5-TRIFLUOROPHENYLACETIC ACID
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, (2019/01/21)
Object of the present invention is an efficient process for the preparation of the active pharmaceutical ingredient Sitagliptine and the 2,4,5-trifluorophenylacetic acid (TFAA) and salt thereof, which is a key intermediate for the synthesis of Sitagliptine.