Preparation method of p-chlorophenol

A technology for p-chlorophenol and phenol, applied in the field of preparation of p-chlorophenol, can solve problems such as a large number of by-products, low para-selectivity, easy environmental pollution, etc., and achieve the effect of high para-selectivity

Pending Publication Date: 2018-04-27
南京大学扬州化学化工研究院
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is simple and easy to operate, but its disadvantage is that the para-selectivity is not high and a large number of by-products are generated
[0004] The sulfuryl chloride method uses sulfuryl chloride as the chlorination agent, and reacts to generate p-chlorophenol in the presence of a catalyst. The catalysts used mainly include iron trichloride, aluminum trichloride, etc., and the selectivity of the target product p-chlorophenol is very high , so this process route is a mature process commonly used in western industrialized countries, but the preparation process of the chlorinating agent sulfuryl chloride is complicated, the cost is high, it is uneconomical, and the reaction of ferric chloride is easy to pollute the environment as waste
[0005] The copper chloride method uses copper chloride as the chlorinating agent, and the selectivity of the target product of this route is relatively high. Japanese patent JPS5436221 uses copper chloride as the chlorinating agent, hyd

Method used

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  • Preparation method of p-chlorophenol

Examples

Experimental program
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Effect test

Example Embodiment

[0026] Example 1:

[0027] Under normal pressure, add 20g of phenol, 36g of copper chloride and 60g of hydrochloric acid to the chlorination reactor. Heat to a reaction temperature of 90°C. Under the protection of nitrogen, let chlorine gas to react until the phenol is completely chlorinated. Cool and remove the upper organic phase. , Get mixed chlorophenol, sample GC analysis content, phenol conversion rate is 97.6%, selectivity of p-chlorophenol is 81.1%, selectivity of o-chlorophenol is 7.6%, and the ratio of p-to-n is 10:1; the lower layer is hydrochloric acid-chlorinated After copper was added to phenol, the chlorination reaction was repeated under the same conditions, and the selectivity to chlorophenol remained stable at about 80% after repeated 8 times.

Example Embodiment

[0028] Example 2:

[0029] Under normal pressure, add 20g of phenol, 60g of copper chloride and 120g of dimethyl sulfoxide into the chlorination reactor, heat the oil bath to 110℃, react for a certain period of time under the protection of nitrogen, cool and filter to obtain copper chloride Solid, sampling GC analysis content, phenol conversion rate is 90.0%, p-chlorophenol selectivity is 82.0%, o-chlorophenol selectivity is 6.1%, and the p-ortho ratio is as high as 12:1.

Example Embodiment

[0030] Example 3:

[0031] Under normal pressure, add 20g of phenol, 36g of copper chloride, 40g of hydrochloric acid and 8g of dimethyl sulfoxide into the chlorination reactor, and heat to a reaction temperature of 90°C. Under the protection of nitrogen, let chlorine gas to react until the phenol is completely chlorinated. Cool, take out the upper organic phase, get the organic solvent and mixed chlorophenol, sample GC to analyze the content, the conversion rate of phenol is 99.6%, the selectivity of p-chlorophenol is 83.5%, the selectivity of o-chlorophenol is 5.9%, and the p-ortho ratio reaches 12:1; After adding phenol and dimethyl sulfoxide to the lower layer of hydrochloric acid-copper chloride, repeat the chlorination reaction under the same conditions. After repeating 5 times, the selectivity of p-chlorophenol is maintained at about 82.5%, and the ratio of to neighbor is maintained at 12:1 keep it steady.

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Abstract

The invention discloses a preparation method of p-chlorophenol. The preparation method comprises feeding chlorine gas into a mixture of phenol, copper chloride and a polar solvent under the normal pressure so that the mixture undergoes a full phenol chlorination reaction, and collecting p-chlorophenol from the chlorination reaction products, wherein the polar solvent is hydrochloric acid, dimethylsulfoxide or their mixed solvent. The preparation method utilizes a one-step reaction method, copper chloride as a chlorinating agent and the polar solvent, solves the problem that the existing copper chloride method needs harsh conditions such as high temperature and high pressure and the copper chloride conversion rate is low because of use of single copper chloride, and has high para-selectivity. After the reaction, the copper chloride-polar solvent can be used for the circular chlorination reaction.

Description

technical field [0001] The invention relates to a preparation method of p-chlorophenol. Background technique [0002] P-Chlorophenol is widely used in medicine, pesticide, dyestuff and other industries, and is an important organic chemical intermediate. Because the dye intermediate 1,4-dihydroxyanthraquinone has a large demand for the raw material p-chlorophenol, the domestic production of p-chlorophenol and the research on process optimization have become a hot spot. [0003] At present, there are three preparation methods of p-chlorophenol, chlorine gas method, sulfuryl chloride method and copper chloride method. In the direct chlorination method, phenol can be chlorinated directly with chlorine gas without a catalyst to generate p-chlorophenol, o-chlorophenol and a small amount of m-chlorophenol. The reaction conditions have a great influence on the selectivity of the target product p-chlorophenol. This method is simple in process and easy to operate, but its disadvanta...

Claims

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Application Information

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IPC IPC(8): C07C37/62C07C39/28
CPCC07C37/62
Inventor 赵兵范以宁张忠良陆海孟惠恩娟周静卫松雪
Owner 南京大学扬州化学化工研究院
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