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Method for synthesizing 2,6-dichloroaniline at low cost

A dichloroaniline, low-cost technology, applied in chemical instruments and methods, preparation of organic compounds, preparation of amino compounds from amines, etc., can solve the problems of expensive raw materials, large amount of sulfuric acid, and high cost, and achieve low cost and product quality. The effect of high yield and low equipment requirements

Inactive Publication Date: 2020-05-08
SHANGYU XIES CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the synthesis methods of 2,6-dichloroaniline are mainly as follows: 1. Using p-nitroaniline as a starting material, after chlorination first, the product is hydrolyzed to remove the sulfonic acid group, and the reported yield is 50%; the raw material of this route is cheap Easy to obtain, but the yield is low, and the amount of sulfuric acid is large, and there are many wastes. The amine group and the sulfonic acid group will form an inner salt to passivate the benzene ring and affect the chlorination.
Two, take p-aminobenzenesulfonamide as starting raw material, methanol as solvent, direct chlorine chlorination, hydrolysis to remove sulfonamide group to obtain product, the reported yield is 60%; the raw material price of this route is expensive, and the cost is high, and the yield is the same lower

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A low-cost method for synthesizing 2,6-dichloroaniline, comprising the following steps:

[0025] (1) Add 5 mol of aniline, 1 mol of urea, 1 mol of xylene, and 0.005 mol of catalyst into the reactor, stir and mix evenly, then raise the temperature to 165°C, and react at constant temperature for 1 hour; The obtained solid was washed successively with deionized water and absolute ethanol, and dried at 75°C for 3 hours to obtain N,N-diphenylurea;

[0026] Wherein, the catalyst used is a mixture of p-toluenesulfonic acid, nickel chloride, and cobalt acetate, and the mass ratio of the three is 3:1:1;

[0027] (2) Add 0.2mol chlorosulfonic acid into the reactor, control the temperature at 10°C, add 0.1mol N,N-diphenylurea under stirring conditions, stir while adding dropwise, and control the temperature of the reaction system during the stirring process to At 10°C, a mixture of 1,3-diphenylureasulfonyl chloride was prepared;

[0028] (3) Add 100ml of deionized water to 0.1mo...

Embodiment 2

[0031] A low-cost method for synthesizing 2,6-dichloroaniline, comprising the following steps:

[0032] (1) Add 5 mol of aniline, 1 mol of urea, 1 mol of xylene, and 0.008 mol of catalyst into the reactor, stir and mix evenly, then heat up to 175°C, and react at a constant temperature for 4 hours; after the reaction is completed, cool to room temperature, and vacuum filter, The obtained solid was washed with deionized water and absolute ethanol in sequence, and dried at 85°C for 6 hours to obtain N,N-diphenylurea;

[0033] Wherein, the catalyst used is a mixture of p-toluenesulfonic acid, nickel chloride, and cobalt acetate, and the mass ratio of the three is 3:1:3;

[0034] (2) Add 0.3mol chlorosulfonic acid into the reactor, control the temperature at 15°C, add 0.1mol N,N-diphenylurea under stirring conditions, stir while adding dropwise, and control the temperature of the reaction system during the stirring process to At 15°C, a mixed solution of 1,3-diphenylureasulfonyl c...

Embodiment 3

[0038] A low-cost method for synthesizing 2,6-dichloroaniline, comprising the following steps:

[0039] (1) Add 5 mol of aniline, 1 mol of urea, 1 mol of xylene, and 0.0055 mol of catalyst into the reactor, stir and mix evenly, then heat up to 168°C, and react at a constant temperature for 2 hours; after the reaction is completed, cool to room temperature, and vacuum filter, The obtained solid was washed successively with deionized water and absolute ethanol, and dried at 75°C for 4 hours to obtain N,N-diphenylurea;

[0040] Wherein, the catalyst used is a mixture of p-toluenesulfonic acid, nickel chloride, and cobalt acetate, and the mass ratio of the three is 3:1:1.5;

[0041] (2) Add 0.22mol chlorosulfonic acid to the reactor, control the temperature to 11°C, add 0.1mol N,N-diphenylurea under stirring conditions, stir while adding dropwise, control the temperature of the reaction system during the stirring process to At 11°C, a mixture of 1,3-diphenylureasulfonyl chloride ...

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Abstract

The invention discloses a method for synthesizing 2,6-dichloroaniline at low cost, which comprises the following steps: preparing N,N-diphenyl urea from aniline, urea, a solvent and a catalyst; then preparing a 1,3-diphenyl urea sulfonyl chloride mixed solution by using a chlorosulfonic acid non-sulfonating agent and using N,N-diphenyl urea as a reaction raw material; feeding chlorine into the reaction system, and carrying out a chlorination reaction to prepare 3,5-dichloro-4-aminobenzenesulfonyl chloride; and finally, carrying out evaporative hydrolysis reaction to obtain the target product 2,6-dichloroaniline. The method is low in raw material cost and high in target yield, and sulfuric acid can be recycled.

Description

Technical field: [0001] The invention relates to the field of organic preparation, in particular to a low-cost method for synthesizing 2,6-dichloroaniline. Background technique: [0002] 2,6-dichloroaniline is an important intermediate in the synthesis of diclofenac and 2,3,4-trichloronitrobenzene, and it is the extrusion product of the third generation of fluoroquinolone acids. 2,6-Dichloroaniline is a white needle-like crystal or crystal, soluble in alcohol, ketone and other organic solvents, slightly soluble in water, toxic and flammable, with a melting point of 3710-3910°C. In recent years, with the rise of new antibacterial drugs containing fluoroquinolone acid accumulation, especially the large-scale production and marketing of ofloxacin, the research on the production technology of the starting material 2,6-dichloroaniline has made rapid progress. The annual demand continues to increase, and at the same time, higher requirements are put forward for the production tec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C209/68C07C273/18C07C211/52C07C275/28
CPCC07C209/68C07C273/1809C07C211/52C07C275/28
Inventor 解卫宇陈少君
Owner SHANGYU XIES CHEM IND