Synthetic method of 2, 6-dichloroaniline

A technology of dichloroaniline and a synthesis method, which is applied in chemical instruments and methods, preparation of amino compounds, preparation of organic compounds, etc., can solve the problem that the cooling effect of decomposition and chlorination reaction equipment is also very high, and 1,3-diphenylene High quality requirements of urea, large equipment and environmental impact, etc., to achieve the effect of less corrosion, simple post-treatment, and small equipment investment

Inactive Publication Date: 2014-01-22
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The process route of this method is long, the operation is complicated, and the quality requirements for 1,3-diphenylurea are high. It must be refined in the production process, and then chlorosulfonic acid is used as a sulfonating agent in the chlorosulfonation process, which has an impact on equipment and the environment. In addition, the cooling effect of decomposition and chlorination reaction equipment is also very high

Method used

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  • Synthetic method of 2, 6-dichloroaniline
  • Synthetic method of 2, 6-dichloroaniline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Embodiment 1, a kind of synthetic method of 2,6-dichloroaniline, take aniline as raw material, carry out the following steps successively:

[0043] (1) Put 13.8g (0.15mol) of aniline, 350mL of 35% concentrated hydrochloric acid (4.0mol) and 350mL of water into a 1L three-necked flask, add 56.3g (0.45mol) of 30wt% hydrogen peroxide dropwise under mechanical stirring, and control the temperature at 60 °C, react for 2h. After the reaction was completed, the reaction solution was cooled in an ice bath to precipitate a solid, which was filtered to obtain 2,4,6-trichloroaniline hydrochloride. The solid 2,4,6-trichloroaniline hydrochloride was added to 300 mL of water, followed by steam distillation to obtain 27.3 g (0.14 mol) of solid 2,4,6-trichloroaniline, with a yield of 92.5%.

[0044] (2) Add the solid 2,4,6-trichloroaniline obtained in step 1) into a 500mL three-necked flask, add 23.1g (0.23mol) of acetic anhydride dropwise under ice bath conditions and mechanical stir...

Embodiment 2

[0047] Embodiment 2, a kind of synthetic method of 2,6-dichloroaniline, take aniline as raw material, carry out the following steps successively:

[0048] (1) Put 13.8g (0.15mol) of aniline, 350mL of 35% concentrated hydrochloric acid and 350mL of water into a 1L three-necked flask, add 56.3g (0.45mol) of 30wt% hydrogen peroxide dropwise under mechanical stirring, control the temperature at 80°C, and react for 1h. After the reaction was completed, the reaction solution was cooled in an ice bath to precipitate a solid, which was filtered to obtain 2,4,6-trichloroaniline hydrochloride. The solid 2,4,6-trichloroaniline hydrochloride was added to 300 mL of water, and steam distillation was performed to obtain 27.0 g (0.14 mol) of solid 2,4,6-trichloroaniline, with a yield of 91.7%.

[0049](2) Add the solid 2,4,6-trichloroaniline obtained in step 1) into a 500mL three-neck flask, add 30.6g (0.30mol) of acetic anhydride dropwise under ice bath conditions and mechanical stirring, an...

Embodiment 3

[0052] Embodiment 3, a kind of synthetic method of 2,6-dichloroaniline, take aniline as raw material, carry out the following steps successively:

[0053] (1) Put 13.8g (0.15mol) of aniline, 350mL of 35% concentrated hydrochloric acid and 350mL of water into a 1L three-neck flask, add 56.3g (0.45mol) of 30wt% hydrogen peroxide dropwise under mechanical stirring, control the temperature at 40°C, and react for 3h. After the reaction was completed, the reaction solution was cooled in an ice bath to precipitate a solid, which was filtered to obtain 2,4,6-trichloroaniline hydrochloride. The solid 2,4,6-trichloroaniline hydrochloride was added to 300 mL of water, and steam distillation was performed to obtain 27.4 g (0.14 mol) of solid 2,4,6-trichloroaniline, with a yield of 93.1%.

[0054] (2) Add the solid 2,4,6-trichloroaniline obtained in step 1) into a 500mL three-necked flask, add 45.9g (0.45mol) of acetic anhydride dropwise under ice bath conditions and mechanical stirring, a...

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Abstract

The invention discloses a synthesis method of 2, 6-dichloroaniline. The method uses aniline as a raw material, and comprises the following steps: 1) adding aniline into dilute hydrochloric acid, then dropwise adding hydrogen peroxide for a chlorination reaction, and adding water into the obtained 2, 4, 6- trichloroaniline hydrochloride to carry out steam distillation, so as to obtain 2, 4, 6-trichloroaniline; 2) reacting 2, 4, 6-trichloroaniline with acetic anhydride to obtain 2, 4, 6-trichloroacetanilide; 3) adding the obtained 2, 4, 6-trichloroacetanilide into an autoclave, then adding a solvent and a catalyst, and filling in hydrogen for a reduction reaction, so as to obtain 2, 6-dichloroacetanilide; and 4) adding 2, 6-dichloroacetanilide into an alkali solution and heating for reaction, so as to finally obtain 2, 6-dichloroaniline. The synthetic method of 2, 6-dichloroaniline has the advantages of low cost, high conversion rate and simple post-treatment, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a synthesis method of 2,6-dichloroaniline. Background technique [0002] 2,6-Dichloroaniline, which has the molecular formula C 6 h 5 Cl 2 N, its structural formula is as follows: [0003] [0004] The pure product of 2,6-dichloroaniline is white needle-like crystal or crystal, which is an important intermediate in the synthesis of diclofenac and 2,3,4-trifluoronitrobenzene, and is the basic product of the third generation of fluoroquinolone acid drugs . [0005] Currently reported mainly contain the following several methods of producing 2,6-dichloroaniline: [0006] Method 1. Using p-aminobenzenesulfonic acid as the starting material, it is prepared through two steps of chlorination and hydrolysis to remove the sulfonic acid group. The yield is 49.4%. The method has low yield and poor quality, and consumes a lot of sulfuric acid, causing great pollution to the three wastes. In addition, the sulfonic acid groups and a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/52C07C209/62
Inventor 陈新志苏佳辉葛新潘炯彬钱超
Owner ZHEJIANG UNIV
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