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Method for preparing m-chlorophenol

A technology of chlorophenol and chloroaniline, which is applied in the field of m-chlorophenol preparation, can solve the problems of high cost of dichlorosulfuryl, corrosion of production equipment, low production capacity, etc., and achieve easy industrial large-scale use and reduce the amount of waste acid produced , The effect of simplifying the production process

Inactive Publication Date: 2019-06-28
海门市五洋化工有限公司
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  • Description
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AI Technical Summary

Problems solved by technology

[0003] Its preparation method has following three kinds at present: Dichlorosulfuryl is used as chlorinating agent to chlorinate phenol, and the para-isomer productive rate of this method is higher, reaches 70%~75%, but, carries out under the presence of iron catalyst The chlorination reaction time is long, the production capacity is low, and the cost of sulfuryl dichloride is higher; another method is to directly chlorinate phenol by feeding chlorine gas. Serious corrosion to production equipment; Another method is to hydrolyze p-chloroaniline to obtain products after diazotization, but more waste liquid is generated, which is easy to cause environmental pollution and waste of resources

Method used

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  • Method for preparing m-chlorophenol
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  • Method for preparing m-chlorophenol

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Preparation of the silica gel-supported catalyst: at 40° C., 162 kg of silica gel was soaked in 98% sulfuric acid for 20 minutes, and then the acid washed off the surface was taken out and dried to obtain 434 kg of silica gel-supported catalyst.

[0023] Diazotization: Add 300kg of water into the reaction kettle, start stirring at 62 rpm, then add 310kg of silica gel-loaded sulfuric acid catalyst, cool with ice-salt water to make the temperature 0°C, and then add 82kg of m-chloroaniline at one time And 150kg of sodium nitrite solution of 20% by mass percentage, control temperature at 15 ℃. After adding, cool it with ice-salt water to lower the temperature below 10°C. After reacting at 10°C for 4 hours, measure the blueness with starch potassium iodide test paper, adjust it with urea solution until it does not turn blue, and filter it with an 80-mesh filter cloth , the filtrate was prepared for hydrolysis, and the filtered silica gel was loaded with a sulfuric acid catal...

Embodiment 2

[0027] Preparation of silica gel supported catalyst: at 37°C, soak 210.6 kg of silica gel in 98% sulfuric acid for 35 minutes, take out the acid washed off the surface and dry to obtain 564.2 kg of silica gel supported catalyst.

[0028] Diazotization: Add 300kg of water into the reaction kettle, start stirring, and the rotation speed is 62 rpm, then add 310kg of silica gel-loaded sulfuric acid catalyst, cool it with ice-salt water to make the temperature 10°C, and then add 82kg of m-chloroaniline and mass Percentage 28% sodium nitrite solution 150kg, control temperature at 35 ℃. After the addition, the temperature was lowered to below 10°C by cooling with ice-salt water. After reacting at 10°C for 5.5 hours, it turned blue with starch potassium iodide test paper, then adjusted with urea solution until it did not turn blue, and filtered with 80-mesh filter cloth , the filtrate was prepared for hydrolysis, and the filtered silica gel was loaded with a sulfuric acid catalyst, pu...

Embodiment 3

[0032] Preparation of silica gel-supported catalyst: at 45° C., 178.2 kg of silica gel was soaked in 98% sulfuric acid for 30 minutes, and then the acid washed off the surface was taken out and dried to obtain 477.4 kg of silica gel-supported catalyst.

[0033] Diazotization: Add 328kg of water into the reaction kettle, start stirring at 62 rpm, then add 328kg of silica gel-supported sulfuric acid catalyst, cool it with low-temperature ethylene glycol to make the temperature 5°C, and then add 82kg of sulfuric acid catalyst at a time Chloroaniline and 30% sodium nitrite solution of mass percentage 164kg, control temperature at 25 ℃. After the addition, the temperature was lowered to below 10°C by cooling with ice-salt water. After reacting at 10°C for 5 hours, it turned blue with starch potassium iodide test paper, then adjusted with urea solution until it did not turn blue, and filtered with 80-mesh filter cloth , the filtrate was prepared for hydrolysis, and the filtered sili...

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Abstract

The invention provides a method for preparing m-chlorophenol. The method comprises the following steps: adding m-chloroaniline and a sodium nitrite solution into a mixture of silica-loaded sulfuric acid catalyst and water, cooling, and performing diazo-reaction to obtain a diazonium salt solution, wherein the weight ratio of the m-chloroaniline, the sodium nitrite solution, the silica-loaded sulfuric acid catalyst and water is 2:(3-4):(6.5-8):(7-8); adjusting the pH value, and filtering to obtain filtrate; adding the filtrate into the mixture of silica-loaded sulfuric acid catalyst and water,performing hydrolysis reaction, wherein the weight ratio of the filtrate, the silica-loaded sulfuric acid catalyst and water is (9-13):(2-3):1; and performing extraction layering and distillation to obtain m-chlorophenol. According to the preparation method, the m-chlorophenol yield is 80 percent or more and is easy for industrial large-scale application; the silica-loaded sulfuric acid catalyst slowly releases concentrated sulfuric acid adsorbed in a silica body in the reacting process; the silica body can repeatedly absorb and utilize remained concentrated sulfuric acid remained after the catalyzing reaction, and waste acid output is remarkably reduced.

Description

technical field [0001] The invention relates to a synthesis method of phenolic compounds, in particular to a preparation method of m-chlorophenol. Background technique [0002] m-Chlorophenol is an important fine chemical raw material, widely used in organic synthesis, pesticides, textiles, medical industry, medicine and other fields. The compound is a colorless solid; its melting point is 33-35°C, its boiling point is 214°C, and its density is 1.218g / cm3 at room temperature; it is easily soluble in alcohol, ether, benzene, and alkali aqueous solution. [0003] Its preparation method has following three kinds at present: Dichlorosulfuryl is used as chlorinating agent to chlorinate phenol, and the para-isomer productive rate of this method is higher, reaches 70%~75%, but, carries out under the presence of iron catalyst The chlorination reaction time is long, the production capacity is low, and the cost of sulfuryl dichloride is higher; another method is to directly chlorinat...

Claims

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Application Information

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IPC IPC(8): C07C39/28C07C37/045C07C37/72C07C245/20
Inventor 陆春辉冯随意
Owner 海门市五洋化工有限公司
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