Preparation method of 1, 3-dichloro-2, 4, 6-trifluorobenzene

A technology of trifluorobenzene and trifluorobenzonitrile, which is applied in the preparation of organic compounds, nitriles, and carboxylic acid nitrile, can solve the problems of long time and high reaction temperature, and achieves easy operation, high yield and content, Process saving effect

Pending Publication Date: 2022-03-11
FUXIN RUIGUANG FLUORINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The patented hydrolysis method adopts acid hydrolysis, which produces a large amo

Method used

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  • Preparation method of 1, 3-dichloro-2, 4, 6-trifluorobenzene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] First step response:

[0025] Take a 2000mL four-neck bottle, connect the stirring, condenser and thermometer casing, add 275.3g of pentachlorobenzonitrile, 680g of DMF, 232g of potassium fluoride and 8.5g of hexamethylguanidine fluoride, stir evenly and raise the temperature to 110°C, and keep it warm for 8h , until the content of difluorotrichlorobenzonitrile ≤ 3%, cooling and filtering. DMF was then concentrated to obtain 185 g of 3,5-dichloro-2,4,6-trifluorobenzonitrile, with a yield of 82%.

[0026] Second step reaction:

[0027] Prepare a total of 540g of 30% sodium hydroxide solution, raise the temperature to 100°C, add 185g of 3,5-dichloro-2,4,6-trifluorobenzonitrile dropwise while stirring, and keep it warm for 6 hours until the raw materials are complete The response is over. The temperature was raised to 130° C., and the decarboxylation reaction was continued for 6 hours until the content of 3,5-dichloro-2,4,6-trifluorobenzoic acid was ≤0.5%, and the react...

Embodiment 2

[0029] First step response:

[0030] Take a 2000mL four-neck bottle, connect the stirring, condenser and thermometer sleeve, add 275.3g of pentachlorobenzonitrile, 720g of DMF, 261g of potassium fluoride and 15g of hexaethylguanidine chloride, stir evenly and raise the temperature to 130°C, keep the temperature for 5h, Until the content of difluorotrichlorobenzonitrile is ≤3%, cool down and filter. DMF was then concentrated to obtain 189.8 g of 3,5-dichloro-2,4,6-trifluorobenzonitrile, with a yield of 84%. Second step reaction:

[0031] Prepare a total of 600g of 20% sodium hydroxide solution, raise the temperature to 105°C, add 189.8g of 3,5-dichloro-2,4,6-trifluorobenzonitrile dropwise while stirring, and keep warm for 7.5h after the dropwise addition, until The raw materials are completely reacted. The temperature was raised to 140° C., and the decarboxylation reaction was continued for 5 hours until the content of 3,5-dichloro-2,4,6-trifluorobenzoic acid was ≤0.5%, and ...

Embodiment 3

[0033] First step response:

[0034] Take a 2000mL four-necked bottle, connect the stirring, condenser and thermometer casing, add 330g of pentachlorobenzonitrile, 924g of DMF and 243.6g of potassium fluoride, stir evenly and raise the temperature to 150°C, keep the temperature for 10h, until difluorotrichlorobenzonitrile Content ≤ 3%, cool down and filter. DMF was then concentrated to obtain 184.4 g of 3,5-dichloro-2,4,6-trifluorobenzonitrile, with a yield of 68%.

[0035] Second step reaction:

[0036] Prepare a total of 540g of 30% sodium hydroxide solution, raise the temperature to 100°C, add 184.4g of 3,5-dichloro-2,4,6-trifluorobenzonitrile dropwise while stirring, and keep warm for 7 hours after the dropwise addition until the raw material Completely reacted. The temperature was raised to 140° C., and the decarboxylation reaction was continued for 5.5 hours until the content of 3,5-dichloro-2,4,6-trifluorobenzoic acid was ≤0.5%, and the reaction was completed. Cool ...

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Abstract

The invention discloses a preparation method of 1, 3-dichloro-2, 4, 6-trifluorobenzene, and belongs to the technical field of pharmaceutical chemicals. The method comprises the following steps: by taking pentachlorobenzonitrile and alkali metal fluoride as raw materials and N, N, N-hexa-substituted guanidine as a catalyst, carrying out fluorination reaction in an organic solvent; the preparation method comprises the following steps: firstly hydrolyzing 3, 5-dichloro-2, 4, 6-trifluorobenzonitrile under the alkaline condition of sodium hydroxide, and then decarboxylating to finally obtain the 1, 3-dichloro-2, 4, 6-trifluorobenzene. The preparation method is simple in process, easy to operate, low in cost and suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of medicine and chemical industry, and mainly relates to the synthesis of 1,3-dichloro-2,4,6-trifluorobenzene. Background technique [0002] 1,3-Dichloro-2,4,6-trifluorobenzene, formula C 6 HCl 2 f 3 , molecular weight 200.97; CAS: 2368-53-8, mainly used in pharmaceutical and chemical intermediates. There are few reports on the synthesis of 1,3-dichloro-2,4,6-trifluorobenzene: [0003] 1) Patent CN105622333 A uses pentachloronitrobenzene as a raw material to obtain a fully halogenated compound through fluorination, reduction, and iodation. The reaction conditions of the method are harsh, the reaction time is long, and the steps are complicated; in particular, the fluorination reaction time is long and the reaction temperature is high, which is unfavorable for industrial production. [0004] 2) Patent CN112608220 A uses pentachlorobenzonitrile as a raw material, undergoes fluorination, hydrolysis and dec...

Claims

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Application Information

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IPC IPC(8): C07C17/363C07C25/13C07C51/08C07C63/70C07C253/30C07C255/50
CPCC07C17/363C07C51/08C07C253/30C07C255/50C07C63/70C07C25/13Y02P20/584
Inventor 李萌萌姜殿宝张洪学昝书金宫春波
Owner FUXIN RUIGUANG FLUORINE CHEM
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