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2,6-dichlorotoluene preparation method

A technology of dichlorotoluene and methylaniline, applied in 2 fields, can solve the problems of high product cost, achieve low production cost, high safety, and be conducive to the effect of resource recycling

Active Publication Date: 2013-09-18
山东福尔有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

And the yield of this method can only reach 40%, and the product cost is also relatively high

Method used

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  • 2,6-dichlorotoluene preparation method
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  • 2,6-dichlorotoluene preparation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Add 3 mol of hydrogen chloride into a 1000 ml three-necked flask equipped with mechanical stirring, a reflux condenser, and a thermometer, then drop 1 mol of 3-chloro-2-methylaniline into the three-necked flask, stir to form off-white particles, and cool to -10 Slowly add 1 mol of sodium nitrite after ℃, control the feeding speed so that the temperature is not higher than 10 ℃, after the addition, stir until the system is brownish red. Then thermal decomposition is carried out, the temperature is controlled at 15°C, and the following chemical reactions occur in the system:

[0015]

[0016] After the reaction is completed, first separate the lower organic phase, absorb the unreacted hydrogen chloride with a graphite absorption tower for recovery, wash the organic phase with water until neutral, remove a small amount of o-chlorotoluene generated in the reaction at 180-196 ° C, and then carry out purification Distillation, collecting 196 ~ 200.5 ° C fractions, to obtai...

Embodiment 2

[0024] Add 2 mol of hydrogen chloride into a 1000 ml three-necked flask equipped with mechanical stirring, a reflux condenser, and a thermometer, then add 1.5 mol of 3-chloro-2-methylaniline dropwise into the three-necked flask, stir to form off-white particles, and cool to - Slowly add 2 mol of potassium nitrite after 10°C, control the feeding speed so that the temperature is not higher than 10°C, and stir until the system is brown-red after adding. Then thermal decomposition is carried out, the temperature is controlled at 40°C, and the following chemical reactions occur in the system:

[0025]

[0026] After the reaction is completed, first separate the lower organic phase, absorb the unreacted hydrogen chloride with a graphite absorption tower for recovery, wash the organic phase with water until neutral, remove a small amount of o-chlorotoluene generated in the reaction at 180-196 ° C, and then carry out purification Distillation, collecting 196 ~ 200.5 ° C fractions t...

Embodiment 3

[0034] Add 1 mol of hydrogen chloride into a 1000 ml three-necked flask equipped with mechanical stirring, reflux condenser, and thermometer, then add 2 mol of 3-chloro-2-methylaniline dropwise into the three-necked flask, stir to form off-white particles, and cool to -10 After ℃, slowly add 2 mol of ammonium nitrite, control the feeding speed so that the temperature is not higher than 10 ℃, after the addition, stir until the system is brown-red. Then thermal decomposition is carried out, the temperature is controlled at 60°C, and the following chemical reactions occur in the system:

[0035]

[0036] After the reaction is completed, first separate the lower organic phase, absorb the unreacted hydrogen chloride with a graphite absorption tower for recovery, wash the organic phase with water until neutral, remove a small amount of o-chlorotoluene generated in the reaction at 180-196 ° C, and then carry out purification Distillation, collecting 196 ~ 200.5 ° C fractions to ob...

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Abstract

The invention discloses a 2,6-dichlorotoluene preparation method which comprises the following steps: mixing and stirring 3-chloro-2-toluidine and acid, cooling the above mixture to a temperature of -10-15 DEG C, adding nitrite, wherein a speed of adding the nitrite is controlled that the temperature of the mixture is not higher than 15 DEG C, followed by stirring, and carrying out a thermal decomposition reaction, wherein the temperature of the mixture is controlled at 15-60 DEG C; after finish of the thermal decomposition reaction, separating lower organic phase, and recycling unreacted acid with a graphite absorbing tower; washing the organic phase with water to a neutral state, carrying out distillation, in a temperature of 180-196 DEG C removing o-chlorotoluene generated in the reaction, carrying out rectification and collecting distillate of 196-200.5 DEG C to obtain the 2,6-dichlorotoluene. The 2,6-dichlorotoluene preparation method in the invention has the advantages of high product yield and low production cost.

Description

technical field [0001] The invention relates to a preparation method of 2,6-dichlorotoluene. Background technique [0002] 2,6-dichlorotoluene is used in the production of 2,6-dichlorobenzaldehyde, 2,6-dichlorobenzonitrile, and intermediates for the preparation of herbicides and dyes. In the prior art, the preparation of 2,6-dichlorotoluene is mainly in the prior art, mainly is to obtain through chlorination reaction with toluene as raw material, expresses as follows with chemical reaction formula: [0003] [0004] Where X is one of Cu, Fe, Sb and Al, and Solvent is chloroform, dichloromethane, water, etc. or no solvent. And the yield of the method can only reach 40%, and the product cost is relatively high. Contents of the invention [0005] The purpose of this invention is to provide a kind of preparation method of 2,6-dichlorotoluene that product yield is high, production cost is low. [0006] The preparation method of 2,6-dichlorotoluene provided by the present ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C25/08C07C17/35
Inventor 于俊田张玲孙志国王洛
Owner 山东福尔有限公司