阅读说明：本技术 4.4-二氯二苯砜制备方法 (Preparation method of 4, 4-dichlorodiphenyl sulfone ) 是由 郑会金 于 2019-09-13 设计创作，主要内容包括：一种4.4-二氯二苯砜制备方法,具体步骤为：先将氯化苯、三氯化铝加入到反应釜搅拌,滴加氯化亚砜,滴加完后保温、升温；之后转入水解釜中,搅拌、升温回流、静止分出三氯化铝,然后启动搅拌,降温,离心得产品亚砜。再将二氯丙烷,催化剂和水、亚砜投入到氧化釜中,升温回流后,再滴入双氧水,保温、静止,蒸馏、分离得到粗品氯苯砜。再将粗品氯苯砜投入反应釜中,加入甲苯,氢氧化钠,硫化钠,升温回流、静止分出不溶物；继续加入氢氧化钠,焦亚硫酸钠,三氧化硫脲和水,再回流、静止分出下层的水,最后加入中性活性炭,回流、脱色、冷却得产品4.4-二氯二苯砜。本发明投料比适中,物料反应彻底,产品收率高,污水排放量少,保护环境。(A preparation method of 4, 4-dichlorodiphenyl sulfone comprises the following specific steps: adding benzene chloride and aluminum trichloride into a reaction kettle, stirring, dropwise adding thionyl chloride, preserving heat and heating after dropwise adding; then transferring into a hydrolysis kettle, stirring, heating up for reflux, standing to separate out aluminum trichloride, starting stirring, cooling, and centrifuging to obtain the product sulfoxide. And then putting dichloropropane, a catalyst, water and sulfoxide into an oxidation kettle, heating and refluxing, then dripping hydrogen peroxide, preserving heat, standing, distilling and separating to obtain a crude product of the chlorosulfonyl. Adding the crude chlorobenzene sulfone into a reaction kettle, adding toluene, sodium hydroxide and sodium sulfide, heating, refluxing, standing and separating out insoluble substances; continuously adding sodium hydroxide, sodium pyrosulfite, sulfur trioxide urea and water, refluxing and standing to separate out the water on the lower layer, finally adding neutral activated carbon, refluxing, decoloring and cooling to obtain the product of 4, 4-dichlorodiphenyl sulfone. The invention has moderate feeding ratio, thorough material reaction, high product yield, less sewage discharge and environmental protection.)

1. A preparation method of 4, 4-dichlorodiphenyl sulfone is characterized by comprising the following steps:

the method comprises the following steps: carrying out a Friedel-crafts reaction; firstly, pumping chlorobenzene into a 3000L reaction kettle through a metering pump, then adding anhydrous aluminum trichloride into the reaction kettle, covering a feeding cover, stirring, dropwise adding thionyl chloride below 25 ℃, preserving heat for 1 hour after dropwise adding is finished, and then heating to 75 ℃; then transferring the mixture into a hydrolysis kettle which is added with 1000kg of purified water, stirring the mixture after transferring the mixture into the hydrolysis kettle, heating the mixture to reflux for 2 hours, stopping stirring the mixture, standing the mixture for 1 hour, separating out aluminum trichloride water, starting stirring, opening cooling water, cooling the mixture to below 20 ℃, and centrifuging the mixture to obtain a product sulfoxide;

step two: carrying out an oxidation reaction; adding the prepared chloropropane, a catalyst and water into an oxidation kettle, adding the sulfoxide obtained in the step one into the oxidation kettle, heating to 80 ℃, refluxing for 30 minutes, dripping 50% hydrogen peroxide into the kettle for 4-4.5 hours, preserving heat for 1 hour, standing for 1 hour, transferring the reaction liquid into a distillation kettle for distillation, cooling for crystallization after dichloropropane is evaporated out, cooling to below 50 ℃, and performing centrifugal separation to obtain a crude product of chlorobenzenesulfone;

step three: refining; putting the dried crude chlorobenzene sulfone into a 5000L reaction kettle, adding toluene in the reaction kettle, adding sodium hydroxide and sodium sulfide, heating to 75 ℃ to start dissolving, refluxing for 1 hour, standing for 40 minutes to separate out insoluble substances, continuing to add sodium hydroxide, sodium pyrosulfite, sulfur trioxide urea and water for the second time after separation, refluxing for 1 hour again, standing for 40 minutes to separate out water at the lower layer, finally adding neutral activated carbon, refluxing for 1 hour, decoloring, transferring into a cooling kettle, cooling for 25 ℃, crystallizing to obtain a product of 4.4 dichlorodiphenyl sulfone, drying, weighing and packaging.

2. The preparation method according to claim 1, wherein the mass ratio of the materials fed in the first step is as follows: the mass ratio of the benzene chloride, the aluminum trichloride and the thionyl chloride is 3-4: 1.1-1.3: 1.

3. The preparation method according to claim 1, wherein the mass ratio of the materials fed in the step two is as follows: the mass ratio of the sulfoxide to the dichloropropane to the water to the 50% hydrogen peroxide to the glacial acetic acid to the sulfuric acid is 25-27: 38-42: 39-41: 9-10: 3.5-4: 1.

4. The preparation method according to claim 1, wherein the material feeding mass ratio in step three is as follows: the mass ratio of the crude chlorobenzene sulfone 13 to the toluene to the sodium hydroxide to the sodium sulfide to the sodium pyrosulfite to the sulfur trioxide urea to the water to the neutral activated carbon is 420-440: 850-870: 13-14: 1.6-1.8: 13-14: 1: 30-35: 13-14.

Technical Field

The invention belongs to the technical field of organic chemical synthesis, and relates to a preparation method of 4, 4-dichlorodiphenyl sulfone.

Background

4, 4-dichlorodiphenyl sulfone is an important organic synthesis product, is a main raw material for preparing engineering plastics such as polysulfone, polyether sulfone and the like, is an intermediate of medicines, fuels, pesticides and the like, can be used for preparing an intermediate of leprosy drugs such as 4, 4-diaminodiphenyl sulfone and the like, and has wide application in the fields of engineering plastics and fine chemical engineering. With the wide application of sulfone series high molecular materials, the demand of 4, 4-dichlorodiphenyl sulfone is increasing.

The industrial production methods of 4, 4-dichlorodiphenyl sulfone are many, and mainly include chlorosulfonic acid method, sulfuric acid method, sulfur trioxide method, sulfoxide oxidation method and the like. The chlorosulfonic acid method is characterized in that chlorobenzene is sulfonated by sulfuric acid to generate p-chlorobenzenesulfonic acid, thionyl chloride is added dropwise to react to prepare p-chlorobenzenesulfonyl chloride, and then the p-chlorobenzenesulfonyl chloride and the chlorobenzene are mixed and catalytically reacted to generate the 4, 4-dichlorodiphenyl sulfone. The chlorosulfonic acid method has mature process, good product quality, high production cost and serious three wastes. The sulfuric acid method is characterized in that chlorobenzene and sulfuric acid are heated to boil, the reaction pressure is controlled, the temperature of reflux reaction liquid is raised to more than 200 ℃, the high-pressure reaction is carried out for more than 10 hours to obtain a mixture containing 4, 4-dichlorodiphenyl sulfone, and the product can be obtained through crystallization and separation. The sulfuric acid method has the advantages of simple raw materials, low production cost, continuity, high reaction temperature, long reaction time, serious equipment corrosion, unstable product quality and lower yield. The method for preparing 4, 4-dichlorodiphenyl sulfone by a sulfur trioxide method is an improved method, and reports that the method is adopted by UCC (American national center of Care) company, a sulfur trioxide sulfonation and thionyl chloride acyl chlorination route is adopted, the process is relatively complex, strong corrosive acid and hazardous gas are involved, and the method is a potential huge hazard to production equipment and human bodies. The sulfoxide oxidation method is characterized in that thionyl chloride and chlorobenzene are subjected to Friedel-crafts reaction under the action of a catalyst to prepare 4, 4-dichlorodiphenyl sulfoxide, and then oxidation reaction is carried out to obtain the 4, 4-dichlorodiphenyl sulfone. The method has the advantages of simple process, low cost, high product purity and easy industrial production. However, the prior art has the disadvantages of overlarge material charging ratio, too short reaction time, incomplete material reaction, low product yield, large sewage discharge amount and environmental pollution.

Disclosure of Invention

In order to solve the defects of the prior art, the invention aims to: provides a preparation method of 4, 4-dichlorodiphenyl sulfone. The method has the advantages of moderate material feeding ratio, thorough material reaction, high product yield and less sewage discharge.

The purpose of the invention is realized by the following technical scheme:

a preparation method of 4, 4-dichlorodiphenyl sulfone comprises the following steps:

the first step is as follows: and (4) carrying out a Friedel-crafts reaction. Firstly, pumping chlorobenzene into a 3000L reaction kettle through a metering pump, then adding anhydrous aluminum trichloride into the reaction kettle, covering a feeding cover, stirring, dropwise adding thionyl chloride below 25 ℃, preserving heat for 1 hour after dropwise adding is finished, and then heating to 75 ℃; and then transferring the mixture into a hydrolysis kettle which is added with 1000kg of purified water, stirring the mixture, heating the mixture to reflux for 2 hours, stopping stirring the mixture, standing the mixture for 1 hour, separating out aluminum trichloride water, starting stirring, opening cooling water, cooling the mixture to a temperature below 20 ℃, and centrifuging the mixture to obtain the product sulfoxide.

In the scheme, the material feeding mass ratio is as follows: the mass ratio of the benzene chloride, the aluminum trichloride and the thionyl chloride is 3-4: 1.1-1.3: 1.

The second step is that: and (4) carrying out oxidation reaction. Adding the prepared chloropropane, glacial acetic acid, sulfuric acid and water into an oxidation kettle, adding the sulfoxide obtained in the step one into the oxidation kettle, heating to 80 ℃, refluxing for 30 minutes, dripping 50% hydrogen peroxide into the kettle for 4-4.5 hours, preserving heat for 1 hour, standing for 1 hour, transferring the reaction liquid into a distillation kettle for distillation, cooling and crystallizing after dichloropropane is evaporated out, cooling to below 50 ℃, and performing centrifugal separation to obtain a crude product of the chlorobenzenesulfone.

In the above scheme, the mass ratio of the materials is as follows: the mass ratio of the sulfoxide to the dichloropropane to the water to the 50% hydrogen peroxide to the glacial acetic acid to the sulfuric acid is 25-27: 38-42: 39-41: 9-10: 3.5-4: 1.

The third step: and (5) refining. Putting the dried crude chlorobenzene sulfone into a 5000L reaction kettle, adding toluene in the reaction kettle, adding sodium hydroxide and sodium sulfide, heating to 75 ℃ to start dissolving, refluxing for 1 hour, standing for 40 minutes to separate out insoluble substances, continuing to add sodium hydroxide, sodium pyrosulfite, sulfur trioxide urea and water for the second time after separation, refluxing for 1 hour again, standing for 40 minutes to separate out water at the lower layer, finally adding neutral activated carbon, refluxing for 1 hour, decoloring, transferring into a cooling kettle, cooling for 25 ℃, crystallizing to obtain a product of 4.4 dichlorodiphenyl sulfone, drying, weighing and packaging.

In the above scheme, the mass ratio of the materials is as follows: the mass ratio of the crude chlorobenzene sulfone 13 to the toluene to the sodium hydroxide to the sodium sulfide to the sodium pyrosulfite to the sulfur trioxide urea to the water to the neutral activated carbon is 420-440: 850-870: 13-14: 1.6-1.8: 13-14: 1: 30-35: 13-14.

Compared with the prior art, the invention has the beneficial effects that: the invention has the advantages of moderate charge ratio of the chlorobenzene, the aluminum trichloride and the thionyl chloride, thorough material reaction and high product yield. The oxidation section prolongs the reaction time, adjusts the components and the proportion of the materials, has thorough material reaction, small danger coefficient, less sewage discharge and environmental protection. The refining section changes the material feeding ratio to ensure thorough reaction, and the sodium metabisulfite and the sodium sulfide are added to remove metal ions which do not exceed the standard and cause environmental pollution.

Detailed Description

The technical solution of the present invention is illustrated below by way of examples, but the present invention is not limited to the following examples.