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Synthesis method of 1,2,4-trifluoro benzene

A synthesis method and technology of trifluorobenzene, applied in chemical instruments and methods, halogenated hydrocarbon preparation, organic chemistry and other directions, can solve the problems of unsatisfactory product purity, harsh reaction conditions, high price, etc., and achieve less impurities and operating conditions. The effect of stable and simplified operation

Active Publication Date: 2015-02-25
ZHEJIANG ZHONGXIN FLUORIDE MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0019] Although the method has easy-to-obtain raw materials and simple synthesis steps, it is expensive and difficult to obtain because the catalyst used is a special catalyst. At the same time, the reaction conditions are very harsh and the purity of the product is not ideal.

Method used

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  • Synthesis method of 1,2,4-trifluoro benzene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0064] Add 166 grams of 30% methylamine aqueous solution into a 500 ml reaction bottle, stir at room temperature, add 114.4 grams of tetrachlorophthalic anhydride (I) in batches, and after the addition is completed, heat up to 40-50o C was reacted for 3 hours and cooled to room temperature to obtain compound (II).

[0065] To the above-mentioned system containing compound (II), add 240 grams of 20% sodium hydroxide solution, stir and cool to -10~0 o C, add 65 grams of zinc powder, temperature control -10 ~ 0 o C reacted for 20 hours, removed the low-temperature bath, returned to room temperature, filtered, and washed the filter cake with water. The filtrate and the washing liquid were combined, the pH was adjusted to acidic with concentrated hydrochloric acid, filtered, and the filter cake was drained to obtain a mixture of compound (III') and compound (III"), with a wet weight of 102 grams.

[0066] In a 500 ml reaction flask, add the mixture of the above compound (III...

Embodiment 2

[0071] Add 155 grams of 40% methylamine aqueous solution in 1 liter reaction bottle, stir and cool to 10 o C, add 286 grams of tetrachlorophthalic anhydride (I) in batches, after adding, control the temperature for 10-20 o C was reacted for 6 hours to obtain compound (II).

[0072] To the above system containing compound (II), add 530 g of 15% sodium hydroxide solution, stir at room temperature, add 130 g of zinc powder, react at room temperature for 10 hours, filter, and wash the filter cake with water beating. Combine the filtrate and the washing liquid, adjust the pH to acidic with concentrated hydrochloric acid, filter, and drain the filter cake to obtain a mixture of compound (III') and compound (III"), with a wet weight of 260 grams.

[0073] In a 1-liter reaction flask, add the mixture of the above-mentioned compound (III') and compound (III"), add 130 grams of toluene, 650 grams of sulfolane, reflux for 15 hours, distill the toluene off, and cool down to room temp...

Embodiment 3

[0078] Add 186 grams of 35% methylamine aqueous solution into a 1-liter reaction bottle, stir at room temperature, add 200 grams of tetrachlorophthalic anhydride (I) in batches, and react at room temperature for 5 hours to obtain compound (II).

[0079] To the above-mentioned system containing compound (II), add 350 grams of 12% sodium hydroxide solution, and control the temperature for 10 to 20 o C, add 68.5 grams of zinc powder, after adding, in 10 ~ 20 o C was reacted for 15 hours. Filter, wash the filter cake twice with 50 g of 1% sodium hydroxide solution, combine the filtrate and washing liquid, adjust the pH to acidic with concentrated hydrochloric acid, filter, and drain the filter cake to obtain compound (III') and compound (III" ) with a wet weight of 168 grams.

[0080] In a 1-liter reaction flask, add the mixture of the above-mentioned compound (III') and compound (III"), add 380 grams of toluene, 420 grams of sulfolane, reflux for 18 hours, distill out the...

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Abstract

The invention discloses a synthesis method of 1,2,4-trifluorobenzene, which belongs to the technical field of chemical synthesis, and is characterized in that it comprises the following reaction steps: (1) reacting tetrachlorophthalic anhydride with methylamine aqueous solution, Obtain 6-carboxy-2,3,4,5-tetrachlorobenzamide; (2) react 6-carboxy-2,3,4,5-tetrachlorobenzamide with zinc powder to obtain 6 -A mixture of carboxy-2,3,5-trichlorobenzamide and 6-carboxy-2,4,5-trichlorobenzamide; (3) 6-carboxy-2,3,5- The mixture of trichlorobenzamide and 6-carboxy-2,4,5-trichlorobenzamide is refluxed in sulfolane and toluene for water separation and ring closure to obtain 3,4,6-trichloro-phthalic acid A mixture of dimethylamide and sulfolane; (4) a mixture of 3,4,6-trichlorophthalamide and sulfolane, reacted with potassium fluoride to obtain 3,4,6-trifluorophthalamide Dicarboxamide; (5) 3,4,6-trifluorophthalamide, hydrolyzed to 3,4,6-trifluorophthalic acid; (6) 3,4,6-trifluorophthalic acid Fluorophthalic acid can be decarboxylated to obtain 1,2,4-trifluorobenzene. The invention has the advantages of easy-to-obtain raw materials, simple and convenient operation, good product purity, etc., and has high industrial application value.

Description

Technical field: [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a synthesis method of 1,2,4-trifluorobenzene. Background technique: [0002] 1,2,4-Trifluorobenzene is an important pharmaceutical intermediate used in the synthesis of Sitagliptin, a drug for treating diabetes. At present, there are not many reports on the synthesis route of 1,2,4-trifluorobenzene at home and abroad, mainly as follows: [0003] (1) Using difluoroaniline as raw material, 1,2,4-trifluorobenzene was synthesized by diazotization and Schiemann reaction: [0004] For example, CN102643160 uses 2,4-difluoroaniline as raw material to synthesize 1,2,4-trifluorobenzene. [0005] . [0006] Another example is CN101817724, which uses 3,4-difluoroaniline as a raw material to synthesize 1,2,4-trifluorobenzene. [0007] . [0008] Although this method has shorter reaction steps, the price of starting materials is more expensive, the reaction c...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C25/13C07C17/363
Inventor 袁其亮杨燕施正军陈寅镐王超
Owner ZHEJIANG ZHONGXIN FLUORIDE MATERIALS CO LTD
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