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Method for preparing 2,4-dichlorophenol by catalytic chlorination of phenol

A phenol-catalyzed chlorine and dichlorophenol technology, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of complex processing, high cost, increased production cost, etc., and achieve high yield and low impurity content low effect

Active Publication Date: 2019-11-15
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] There are some shortcomings in the above process. The first process uses dichloroethane as solvent, which is complicated to handle and high in cost.
The 2,4-dichlorophenol obtained by the second process has a purity of only 95%. If it is not purified, it cannot be directly used in the production of 2,4-D, etc., and the raw material of o-chlorophenol and sulfonyl chloride are used as the chlorination agent. increased production costs

Method used

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  • Method for preparing 2,4-dichlorophenol by catalytic chlorination of phenol
  • Method for preparing 2,4-dichlorophenol by catalytic chlorination of phenol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Serial number Retention time, min Component name 113.837 2-chlorophenol 217.778 phenol 321.724 2,4-Dichlorophenol 435.387 4-chlorophenol

[0025] *The retention time of each component will have a small deviation every time the gas chromatographic detection is performed

[0026] The chlorinated phenol product was diluted with toluene and then tested in the gas phase. Under the same conditions, pure toluene, 2-chlorophenol, phenol, 2,4-dichlorophenol, and 4-chlorophenol were tested in the gas phase. The retention time of each substance was determined as shown in the table above. , The retention time is toluene at 4.0min, which is not considered here.

[0027] After the reaction, the GC test results are as follows figure 1 As shown, the dilution solvent toluene with a retention time of about 4.0 is not discussed here. According to the previous description, the retention time at 21.733 min is 2,4-dichlorophenol. According to the area normalization method, the content of 2,4-...

Embodiment 2

[0030] Except that the co-catalyst was changed to 0.120g o-aminothiophenol, the rest was the same as in Example 1. The gas phase detection reaction mixture, the content of 2,4,-dichlorophenol was 97.2%.

Embodiment 3

[0032] Except that the co-catalyst was changed to 0.191g of phenothiazine, the rest was the same as in Example 1; the gas phase detection reaction mixture, the content of 2,4,-dichlorophenol was 97.8%.

[0033] Examples 1-3 tested the influence of the method by changing the promoter. It can be seen from the results that when Fe powder is used as the catalyst, the effect of using phenothiazine as the promoter is better.

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Abstract

The invention belongs to the field of preparation of fine chemical intermediate 2,4-dichlorophenol, and particularly relates to a method for preparing 2,4-dichlorophenol by catalytic chlorination of phenol. According to the method, phenol and chlorine are used as raw materials, Fe powder or FeCl3 is added as a catalyst, p-toluenethiol or o-aminobenzenethiol or phenothiazine is added as a cocatalyst, and the phenol is chlorinated to prepare 2,4-dichlorophenol. The method is simple and convenient to operate, the conversion rate of phenol is 100%, and the yield is high. The prepared 2,4-dichlorophenol can be directly used as a raw material of a 2,4-D raw drug, and in addition, the content of impurities such as by-product 2,6-dichlorophenol, 2,4,6-trichlorophenol and the like is low.

Description

Technical field [0001] The invention belongs to the field of preparation of fine chemical intermediate 2,4-dichlorophenol, and specifically relates to a method for preparing 2,4-dichlorophenol by catalytic chlorination of phenol. Background technique [0002] 2,4-Dichlorophenol, the English name: 2,4-Dichlorophenol, is a synthetic pesticide herbicide, 2,4-D, Toxan, Ibiphos, pharmaceutical thiobisdichlorophenol and antifungal agent TCS, etc. body. Its structural formula is as follows: [0003] [0004] The output of 2,4-dichlorophenol produced by the traditional phenol catalytic chlorination method does not exceed 90% and cannot be directly used for production. The impurity 2,6-dichlorophenol is the same as 2,4-dichlorophenol due to its physical properties. The phenol is close and cannot be separated. With the demand for high-purity 2,4-dichlorophenol in the pharmaceutical and pesticide industries, there is an urgent need to synthesize and prepare high-purity 2,4-dichlorophenol....

Claims

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Application Information

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IPC IPC(8): C07C37/62C07C39/30
CPCC07C37/62C07C39/30Y02P20/52
Inventor 王明亮叶婷婷乔宾江周宇王萌
Owner SOUTHEAST UNIV
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