Safe and green production method of high-quality 2, 6-difluoroaniline

A green production technology for difluoroaniline, applied in chemical instruments and methods, preparation of organic compounds, preparation of amino compounds, etc., can solve the problems of reducing the purity of raw materials and products, and achieve the effect of reducing the amount of waste water produced

Inactive Publication Date: 2020-10-16
恒劲生物技术(大连)有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Adopting the method of the present invention can effectively solve the problem that the degradation reaction is violently exothermic, resulting in the reduction of raw material and produ

Method used

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  • Safe and green production method of high-quality 2, 6-difluoroaniline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Hofmann degradation reaction stages:

[0027] 2050 kilograms of water and 407 kilograms of sodium hydroxide are dropped into the reactor. Cool down to 25-35°C, and add 800 kg of 2,6-difluorobenzamide. Control the temperature at 25-35°C and add 4360 kg of sodium hypochlorite from the elevated tank. After sodium hypochlorite was added, the reaction was continued for 1.5 hours. At this point the system clarifies.

[0028] Steam distillation stage:

[0029] Put 2050 kilograms of water into another reactor, heat up to reflux with steam. Pump the above-mentioned reaction solution after the reaction to the high-level tank, and add the above-mentioned boiling water at 25-35°C while keeping it warm. At this time, a product will be formed and evaporated with water vapor. When the reaction solution was added, continue to distill until the distillate was clear and free of oil. Distillation continues until 4500 kg of recovered water is collected. The residual waste water wei...

Embodiment 2

[0033] Hofmann degradation reaction stages:

[0034] 2050 kilograms of water and 567 kilograms of potassium hydroxide are dropped into the reactor. Cool down to 25-35°C, and add 800 kg of 2,6-difluorobenzamide. Control the temperature at 25-35°C and add 4360 kg of sodium hypochlorite from the elevated tank. After sodium hypochlorite was added, the reaction was continued for 1.5 hours. At this point the system clarifies.

[0035] Steam distillation stage:

[0036] Put 2050 kilograms of water into another reactor, heat up to reflux with steam. Pump the above-mentioned reaction solution after the reaction to the high-level tank, and add the above-mentioned boiling water at 25-35°C while keeping it warm. At this time, a product will be formed and evaporated with water vapor. When the reaction solution was added, continue to distill until the distillate was clear and free of oil. Distillation continues until 4500 kg of recovered water is collected. The residual waste water ...

Embodiment 3

[0038] 2050 kilograms of embodiment one reclaimed water and 407 kilograms of sodium hydroxide are dropped in the reactor. Cool down to 25-35°C, and add 800 kg of 2,6-difluorobenzamide. Control the temperature at 25-35°C and add 4360 kg of sodium hypochlorite from the elevated tank. After sodium hypochlorite was added, the reaction was continued for 1.5 hours. At this point the system clarifies.

[0039] Steam distillation stage:

[0040] In another reactor, drop into 2050 kilograms of the reclaimed water in embodiment one, heat up to reflux with steam. Pump the above-mentioned reaction solution after the reaction to the high-level tank, and add the above-mentioned boiling water at 25-35°C while keeping it warm. At this time, a product will be formed and evaporated with water vapor. When the reaction solution was added, continue to distill until the distillate was clear and free of oil. Distillation continues until 4500 kg of recovered water is collected. The residual wast...

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Abstract

The invention discloses a safe and green production method of high-quality 2, 6-difluoroaniline, and belongs to the field of fine chemical engineering. 2, 6-difluoroaniline, sodium hypochlorite, water/recycled water and sodium hydroxide/potassium hydroxide are used as raw materials for reaction; the violent heating process of the Hofmann degradation reaction is avoided in a manner of steaming outthe product while feeding, and meanwhile, the product is rapidly separated from a high-temperature system through steam distillation, so that the generation amount of impurities is reduced, and the high-purity 2, 6-difluoroaniline is obtained. The purity of the obtained 2, 6-difluoroaniline is greater than 99.9%, the maximum single impurity content is less than 0.10%, and the water content is lessthan 0.10%. According to the method, the water phase separated from the water vapor distillate is directly reused, so that the wastewater discharge is greatly reduced, the green production of the 2,6-difluoroaniline is realized, the pollution in the whole operation process is small, and the production process is safe and reliable.

Description

technical field [0001] The invention relates to a safe and green production method of high-quality 2,6-difluoroaniline, which belongs to the technical field of fine chemicals. Background technique [0002] 2,6-Difluoroaniline, CAS: 5509-65-9, colorless or pale yellow liquid, boiling point 144°C-148°C. It is mainly used as a key intermediate for the synthesis of new pesticides, insecticides and herbicides, and can also be used to prepare liquid crystal materials for fuel cells and electronics industries. [0003] The synthesis method reported in the current literature is mainly to use 2,6-difluorobenzamide as raw material to obtain 2,6-difluoroaniline after Hoffman degradation reaction, and the typical reagents of Hoffmann amide degradation reaction are sodium hypochlorite or hypobromide Sodium acid. Its reaction mechanism is shown in the following formula: [0004] [0005] Above-mentioned mechanism shows: 1, substrate benzamide reacts with sodium hypochlorite to gener...

Claims

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Application Information

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IPC IPC(8): C07C209/62C07C209/86C07C211/52
CPCC07C209/62C07C209/86
Inventor 张同斌姜殿平
Owner 恒劲生物技术(大连)有限公司
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