CN108069834B

CN108069834B - Method for continuously preparing 3, 4' -dichlorodiphenyl ether

Info

Publication number: CN108069834B
Application number: CN201611014778.3A
Authority: CN
Inventors: 孙亮; 郑卓; 徐雪峰; 薛兴亚; 梁鑫淼
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2016-11-18
Filing date: 2016-11-18
Publication date: 2020-11-10
Anticipated expiration: 2036-11-18
Also published as: CN108069834A

Abstract

The invention discloses a new method for continuously preparing 3, 4' -dichlorodiphenyl ether, which comprises the following steps: (1) preparing parachlorophenol into sodium phenolate, dehydrating, and adding a solvent, an emulsifier and a copper-series, zinc-series or iron-series catalyst to prepare a mixed system; (2) pumping the mixed system into a tubular reactor by using a liquid phase pump, wherein the reaction temperature is 140-. Compared with the traditional kettle type reaction, the invention greatly improves the reaction speed and shortens the reaction time. The reaction selectivity is improved from 85% to 90%, the reaction yield is improved from 80% to 85%, and the reaction yield and the selectivity are improved, so that the production efficiency and the safety are improved, the waste discharge is reduced, and the investment of reaction equipment is greatly reduced. Is a novel method with safety, high efficiency and environmental protection.

Description

Method for continuously preparing 3, 4' -dichlorodiphenyl ether

Technical Field

The invention relates to a new method and a new process for preparing 3, 4 '-dichlorodiphenyl ether by high-selectivity catalysis and continuous preparation, wherein the 3, 4' -dichlorodiphenyl ether is an important pesticide intermediate, the applied catalysts are copper, iron and zinc series catalysts, and the technical field of the invention belongs to the field of catalytic chemistry and fine chemical engineering.

Background

Diaryl ether compounds are important medical and pesticide intermediates, wherein 3, 4' -dichlorodiphenyl ether is an important intermediate of pesticide difenoconazole. The difenoconazole, also called difenoconazole, has a trade name of 'shigao', belongs to triazole bactericides, is a sterol demethylation inhibitor, has the characteristics of high efficiency, broad spectrum, low toxicity and low dosage, is an excellent variety of the triazole bactericides, has extremely strong systemic property, can destroy the cell membrane structure and function of pathogenic bacteria by inhibiting the biosynthesis of bacterial cell ergosterol, is used for crops such as fruit trees, vegetables, wheat, potatoes, beans, melons and the like, has good protection and treatment effects on various fungal diseases such as vegetables, melons and fruits and the like, has the characteristics of 'three-in-one' (no environmental pollution, no agricultural product pollution and no natural enemy killing), and is an ideal bactericide for preventing and treating the resistance diseases of crops such as scab, alternaria leaf spot and the like in China and all countries in the world at present. At present, the domestic yield is about 4000 tons, five manufacturers exist, and the requirement on 3, 4' -dichlorodiphenyl ether exceeds 3000 tons.

The current literature reports (such as domestic patents CN101423460, CN102516044 and CN103073408) that the methods for producing 3, 4' dichlorodiphenyl ether are all batch type kettle reaction methods, and the specific reaction process is as follows: CuCl is used as a catalyst, DMSO is used as a solvent, and p-chlorophenol and m-dichlorobenzene react for at least 10 hours under the action of NaOH at the reaction temperature of 180-220 ℃ to generate 3, 4' -dichlorodiphenyl ether. The reaction selectivity is low, the highest yield is about 80%, and simultaneously, about 20% of solid waste is generated, so that the method is a low-efficiency and non-environment-friendly process technology.

Disclosure of Invention

The invention applies nanometer or soluble Cu series, Fe series and Zn series catalysts, adopts a tubular reactor, and prepares the 3, 4' -dichlorodiphenyl ether by a continuous reaction mode, and the generated product quickly flows out of the system in the continuous reaction process, thereby avoiding the generation of byproducts by further reaction with the raw material of sodium parachlorophenolate and further improving the selectivity.

The reaction is as follows:

side reaction:

the technical scheme of the invention is as follows: provides a method for continuously preparing 3, 4' -dichlorodiphenyl ether, which comprises the following steps:

(1) adding p-chlorophenol, sodium hydroxide and m-dichlorobenzene into a reaction kettle, starting stirring, heating, decompressing and dehydrating, and adding a solvent, an emulsifier and a catalyst to prepare a mixed system.

(2) Pumping the mixed solution into a tubular reactor by a liquid phase pump, wherein the tubular reactor is pre-treated with N₂After displacement, the pressure is set at a certain value. The residence time of the reaction liquid in the tubular reactor is 20-50min, and the reaction liquid enters a collector after passing through a condenser. And filtering the reaction liquid in the collector, distilling to recover the solvent and purifying to obtain the final product.

The method comprises the step (1) that the molar ratio of p-chlorophenol to sodium hydroxide to m-dichlorobenzene is 1: 1-1.05: 7-10, preferably 1: 1-1.02: 9 to 10.

The catalyst in the step (1) of the method is nano copper powder, nano CuCl, nano CuI, nano CuO or nano Cu₂O、CuSO₄、Cu(OAc)₂、C₃-C₁₈The dosage of the fatty acid copper or the nanometer zinc powder and the nanometer iron powder is 1 to 2 percent of the mass of the parachlorophenol.

The solvent in the step (1) of the method is dimethyl sulfoxide, N dimethylformamide, N dimethylacetamide and N-methylpyrrolidone, and the molar ratio of the dosage of the solvent to p-chlorophenol is 0.4-1.2: 1.

the emulsifier in the step (1) of the method is polyvinylpyrrolidone, octadecylbenzotriazole, polyglycerol stearate, emulsifier OP-10, tween-80, oleic acid, SPAN-80, polyethylene glycol 4000, methyl methacrylate and stearic acid, and the using amount of the emulsifier is 1-4% of the mass fraction of the catalyst.

The pressure in step (2) of the above method is set to 0.1 to 0.4MPa, preferably 0.2 to 0.3 MPa. The temperature of the tubular reactor is 140-200 ℃, and the flow rate of the reaction solution is 1-1.2 ml/min.

The reaction speed is greatly improved by adopting the nano-scale copper catalyst and the tubular reactor, the reaction is finished within 1h, the production period is shortened, the treatment capacity is increased, and the productivity can be effectively improved.

The yield of the method is 80-85%.

Compared with the traditional kettle type reaction, the invention greatly improves the reaction speed and shortens the reaction time. The reaction selectivity is improved from 85% to 90%, the reaction yield is improved from 80% to 85%, and the reaction yield and the selectivity are improved, so that the production efficiency and the safety are improved, the waste discharge is reduced, and the investment of reaction equipment is greatly reduced. Is a novel method with safety, high efficiency and environmental protection.

Drawings

FIG. 1 is a schematic diagram of a tubular reactor apparatus for the continuous preparation of 3, 4' -dichlorodiphenyl ether in accordance with the present invention.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.

Example 1

A500-ml round-bottomed flask was charged with 50g (0.39mol) of p-chlorophenol, 16.3g of NaOH (0.41mol), 572g (3.9mol) of m-dichlorobenzene, 15.5g (0.2mol) of DMSO, reacted at 90 ℃ for 1 hour, then charged with 1g of CuCl catalyst, and reacted at 175 ℃ for 2 hours. Detecting the reaction condition of the reaction solution by high performance liquid chromatography, wherein the residual p-chlorophenol sodium is within 1%. After the reaction solution was filtered, m-dichlorobenzene and DMSO were recovered by distillation, and the remaining fraction was distilled under reduced pressure to obtain 74.4g of a product having a content of 98.9% and a yield of 80%.

Example 2

A500-ml round-bottomed flask was charged with 50g (0.39mol) of p-chlorophenol, 15.5g of NaOH (0.39mol), 572g (3.9mol) of m-dichlorobenzene, reacted at 90 ℃ for 1 hour, and then, water was removed under reduced pressure. DMSO (30.3 g, 0.39mol), polyvinylpyrrolidone (0.2 g) and CuCl catalyst (1 g) were added. Tubular reactor through N₂After three replacements, the pressure was set at 0.3 MPa. Pumping the mixed system into a tubular reactor through a high-pressure liquid phase pump, wherein the flow rate is 1.2ml/min, the retention time is 40min, and the reaction temperature is 175 ℃. Detecting the reaction condition of the reaction solution in the collector by high performance liquid chromatography, wherein the residual p-chlorophenol sodium is within 1%. After the reaction solution is filtered, m-dichlorobenzene and DMSO are recovered by distillation, and the residual fraction is subjected to reduced pressure distillation to obtain 76.2g of a product with the content of 99.3 percent and the yield of 85 percent.

Example 3

A500 ml round bottom flask was charged with 50g (0.39mol) of p-chlorophenol, 15.5g of NaOH (0.39mol), 572g (3.9mol) of metachlorDichlorobenzene is reacted for 1 hour at 90 ℃, and then water is removed under reduced pressure. 30.3g (0.39mol) of DMSO, 0.2g of polyvinylpyrrolidone and 1g of nanoscale iron powder catalyst are added. Tubular reactor through N₂After three replacements, the pressure was set at 0.3 MPa. Pumping the mixed system into a tubular reactor through a high-pressure liquid phase pump, wherein the flow rate is 1.2ml/min, the retention time is 40min, and the reaction temperature is 175 ℃. Detecting the reaction condition of the reaction liquid in the collector by high performance liquid chromatography. After the reaction solution was filtered, m-dichlorobenzene and DMSO were recovered by distillation, and the remaining fraction was distilled under reduced pressure to obtain 35.3g of a product with a content of 98.6% and a yield of 38%.

Example 4

A500-ml round-bottomed flask was charged with 50g (0.39mol) of p-chlorophenol, 15.5g of NaOH (0.39mol), 572g (3.9mol) of m-dichlorobenzene, reacted at 90 ℃ for 1 hour, and then, water was removed under reduced pressure. 30.3g (0.39mol) of DMSO, 0.2g of polyvinylpyrrolidone and 1g of nano-zinc powder catalyst are added. Tubular reactor through N₂After three replacements, the pressure was set at 0.3 MPa. Pumping the mixed system into a tubular reactor through a high-pressure liquid phase pump, wherein the flow rate is 1.2ml/min, the retention time is 40min, and the reaction temperature is 175 ℃. Detecting the reaction condition of the reaction liquid in the collector by high performance liquid chromatography. After the reaction solution was filtered, m-dichlorobenzene and DMSO were recovered by distillation, and the remaining fraction was distilled under reduced pressure to obtain 51.2g of a product with a content of 98.4% and a yield of 55%.

Example 5

A500-ml round-bottomed flask was charged with 50g (0.39mol) of p-chlorophenol, 15.5g of NaOH (0.39mol), 572g (3.9mol) of m-dichlorobenzene, reacted at 90 ℃ for 1 hour, and then, water was removed under reduced pressure. DMSO 30.3g (0.39mol), polyvinylpyrrolidone 0.2g, nano-sized CuCl catalyst 1g were added. Tubular reactor through N₂After three replacements, the pressure was set at 0.3 MPa. Pumping the mixed system into a tubular reactor through a high-pressure liquid phase pump, wherein the flow rate is 1ml/min, the retention time is 48min, and the reaction temperature is 165 ℃. Detecting the reaction condition of the reaction liquid in the collector by high performance liquid chromatography. After the reaction solution was filtered, m-dichlorobenzene and DMSO were recovered by distillation, and the remaining fraction was distilled under reduced pressure to give 77.9g of a product with a content of 99% and a yield of 83.8%.

Example 6

A500 ml round bottom flask was charged with 50g (0.39mol) of p-chlorophenol, 15.5g of NaOH (0.39mol), 572g (3.9mol)mol) m-dichlorobenzene, reacting for 1h at 90 ℃, and then removing water under reduced pressure. DMSO 30.3g (0.39mol), polyvinylpyrrolidone 0.2g, nano-sized CuCl catalyst 1g were added. Tubular reactor through N₂After three replacements, the pressure was set at 0.3 MPa. Pumping the mixed system into a tubular reactor through a high-pressure liquid phase pump, wherein the flow rate is 1.2ml/min, the retention time is 40min, and the reaction temperature is 175 ℃. Detecting the reaction condition of the reaction liquid in the collector by high performance liquid chromatography. After the reaction solution is filtered, m-dichlorobenzene and DMSO are recovered by distillation, and the residual fraction is subjected to reduced pressure distillation to obtain 79.5g of a product with the content of 99.5 percent and the yield of 85.6 percent.

Claims

1. The continuous preparation process of 3, 4' -dichloro diphenyl ether includes the following steps:

adding p-chlorophenol, sodium hydroxide and m-dichlorobenzene into a reaction kettle, dehydrating, adding a solvent, an emulsifier and a catalyst, and preparing a mixed system; the system carries out continuous reaction in a tubular reactor; the solvent used in the system is one or more than two of dimethyl sulfoxide, N dimethylformamide, N dimethylacetamide and N-methylpyrrolidone, and the catalyst is nano CuCl, nano CuI, nano CuO and nano Cu₂One or more than two of O, the dosage of which is 1 to 2 percent of the mass of the parachlorophenol;

the emulsifier used in this system is polyvinylpyrrolidone.

2. The method as set forth in claim 1, wherein the molar ratio of the solvent to the p-chlorophenol is 0.4 to 1.2: 1.

3. the method as set forth in claim 1, wherein the emulsifier is used in an amount of 0.1 to 4% by mass based on the catalyst.

4. The method as set forth in claim 1, wherein the reaction temperature of the system is in the range of 140 ℃ to 200 ℃.

5. The method as set forth in claim 1 or 4, wherein the reaction retention time of the system is 20 to 50 min.

6. The method as set forth in claim 1, characterized in that the molar ratio of the materials of the system is p-chlorophenol: sodium hydroxide: m-dichlorobenzene = 1: 1-1.05: 7 to 10.

7. The method as set forth in claim 1 or 4, wherein the reaction pressure of the system is 0.1 to 0.4MPa, and the carrier gas is N₂。