Synthesis method of 3-chloro-2-(4-chlorphenyl)-1-(2-chlorphenyl)-propylene

Abstract

The invention belongs to the field of compound preparation, and particularly relates to a synthesis method of 3-chloro-2-(4-chlorphenyl)-1-(2-chlorphenyl)-propylene. The method comprises the following steps: reacting 1-chloro-2-(4-chlorphenyl)-3-(2-chlorphenyl)-2-propanol with thionyl chloride under the action of a catalyst to generate 3-chloro-2-(4-chlorphenyl)-1-(2-chlorphenyl)-propylene. According to the method, thionyl chloride is used as a hydrophilic agent, the selectivity of the product 3-chloro-2-(4-chlorphenyl)-1-(2-chlorphenyl)-propylene Z body is improved, byproducts are fewer, the product yield is higher, water generated in the reaction reacts with thionyl chloride to generate hydrogen chloride and sulfur dioxide, water generated in the reaction reacts with thionyl chloride to generate hydrogen chloride and sulfur dioxide, and the product yield is higher. Hydrochloric acid is absorbed and recycled by hydrogen chloride water, and sulfur dioxide is prepared into sodium sulfite for sale after alkali absorption, so that generation and treatment of high-COD (Chemical Oxygen Demand) wastewater are avoided, and the production and environmental protection cost is greatly reduced while the reaction yield is improved.

Description

Technical Field

[0001] The invention belongs to the field of compound preparation, and specifically relates to a method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene. Background Art

[0002] Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene is an important intermediate in the synthesis of epoxiconazole and is also the process step with the lowest yield in the production process of epoxiconazole, which restricts the total yield and production cost of the synthesis of epoxiconazole. The existing preparation method has poor selectivity. Since acetic anhydride is used as a hydrophilic agent, acetic anhydride is hydrolyzed to generate acetic acid, and acetic acid is dissolved in water during the product separation process, resulting in a large amount of high COD wastewater with poor biodegradability. Wastewater treatment requires another set of treatment processes to remove acetic acid in water before biochemical treatment, which uses more equipment and labor, and consumes more energy, raw materials and costs.

[0003] Therefore, a synthetic process with high product selectivity and environmental protection is needed. Summary of the invention

[0004] In view of the above-mentioned shortcomings and deficiencies of the prior art, the object of the present invention is to provide a synthesis process with high product selectivity, and the process provides a more environmentally friendly method for preparing the fluopicolide intermediate Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for synthesizing a 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene isomer is disclosed. 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol reacts with thionyl chloride in the presence of a catalyst to generate a 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene isomer.

[0007] The reaction formula is as follows:

[0008]

[0009] Specifically, 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol is dissolved in a solvent, a catalyst is added, thionyl chloride is added dropwise at 0-80°C, and after the addition is completed, reflux for 1-2 hours to obtain 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0010] Furthermore, after the reflux is completed, the oil phase is washed with water, washed with alkali, and desolventized to obtain a crude oily substance, which is then refined by recrystallization to obtain a fine product 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene Z-isomer.

[0011] Wherein, the molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:1 to 1:2.5.

[0012] The catalyst is one or more of sulfuric acid, phosphoric acid, p-toluenesulfonic acid or anhydrous oxalic acid; the mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to the catalyst is 1:0.01 to 1:0.5.

[0013] The solvent is toluene, ether, tetrahydrofuran, dichloroethane, chloroform, and dichloromethane.

[0014] The recrystallization solvent is one or more of toluene, methanol, ethanol, isopropanol, and cyclohexane; the mass ratio of the crude oil to the recrystallization solvent is 1:0.3 to 1:2.

[0015] The advantages of the present invention are:

[0016] The invention uses thionyl chloride as a hydrophilic agent, improves the selectivity of the product 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene Z-form, has fewer by-products and higher product yield, reacts water generated by the reaction with thionyl chloride to generate hydrogen chloride and sulfur dioxide, reacts water generated by the reaction with thionyl chloride to generate hydrogen chloride and sulfur dioxide, absorbs the hydrogen chloride water to recover hydrochloric acid for use, and absorbs the sulfur dioxide with alkali to prepare sodium sulfite for sale, thereby avoiding the generation and treatment of high COD wastewater, improving the reaction yield and greatly reducing the production and environmental protection costs.

[0017] 1. The present invention uses thionyl chloride as a hydrophilic agent to replace traditional acetic anhydride, significantly improves the selectivity of the target product Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene, reduces the generation of by-products, and thus improves the product yield.

[0018] 2. In the reaction process of the present invention, thionyl chloride reacts with water to generate hydrogen chloride and sulfur dioxide, which can be recycled or sold, thus avoiding the generation of high COD wastewater and reducing the complexity and cost of wastewater treatment.

[0019] 3. Since the generation of high COD wastewater is avoided, the present invention is more environmentally friendly and reduces environmental pollution.

[0020] 4. The present invention reduces the overall production cost and improves economic benefits by improving raw material utilization and reducing wastewater treatment costs.

[0021] 5. The hydrogen chloride and sulfur dioxide produced in the present invention can be recycled or sold, achieving effective recycling and reuse of resources and further reducing production costs. DETAILED DESCRIPTION

[0022] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods.

[0023] Example 1

[0024]

[0025] Dissolve 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol in dichloroethane, add p-toluenesulfonic acid as a catalyst, add thionyl chloride dropwise at 20°C, heat and reflux for 1 hour after the addition is complete, filter the oil phase, wash with water, wash with alkali, and desolventize to obtain a crude oily substance, which is then refined by recrystallization from methanol and toluene to obtain a fine product Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0026] The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:1.5.

[0027] The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to p-toluenesulfonic acid is 1:0.05.

[0028] The mass ratio of crude 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to methanol and toluene is 1:1, and the mass ratio of methanol to toluene is 1:0.05.

[0029] The reaction yield was 70%, and the content of Z-1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was 99%.

[0030] Example 2

[0031]

[0032] Dissolve 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol in ether, add anhydrous oxalic acid and phosphoric acid mixed acid as catalyst, add thionyl chloride dropwise at 35°C, continue to reflux for 2 hours after the addition is completed, wash the oil phase with water, wash with alkali, and desolventize to obtain a crude oily product, which is then refined by recrystallization from methanol and toluene to obtain a fine product 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0033] The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:2.5.

[0034] The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to the mixed acid is 1:0.25, and the mass ratio of phosphoric acid to anhydrous oxalic acid is 4:1.

[0035] The mass ratio of crude 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to methanol and toluene is 1:1, and the mass ratio of methanol to toluene is 1:0.1.

[0036] The reaction yield was 64%, and the content of Z-1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was 98%.

[0037] Example 3

[0038]

[0039] 1-Chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was dissolved in dichloroethane, sulfuric acid as a catalyst was added, thionyl chloride was added dropwise at a micro-reflux temperature of about 80°C, and reflux was continued for 2 hours after the addition was completed. After the reaction, the oil phase was washed with water, washed with alkali, and desolventized to obtain a crude oily product, which was then recrystallized and refined with methanol and toluene to obtain a fine product 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0040] The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:2.5.

[0041] The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to sulfuric acid is 1:0.025.

[0042] The mass ratio of crude 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to methanol and toluene is 1:1, and the mass ratio of methanol to toluene is 1:0.1.

[0043] The reaction yield was 66%, and the content of Z-1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was 96%.

[0044] Comparative Example 1

[0045] The difference from Example 1 is that the hydrophilic agent is acetic anhydride, and there is no temperature rise and reflux process after the dropwise addition is completed. The other conditions are the same as those in Example 1, specifically:

[0046] Dissolve 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol in dichloroethane, add p-toluenesulfonic acid as a catalyst, add acetic anhydride dropwise at 20°C, keep warm for 2 hours after the addition is completed, filter the oil phase after the reaction, wash with water, wash with alkali, and desolventize to obtain a crude oily substance, which is then refined by recrystallization from methanol and toluene to obtain the fine product Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0047] The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to acetic anhydride is 1:1.5.

[0048] The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to p-toluenesulfonic acid is 1:0.05.

[0049] The mass ratio of crude 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to methanol and toluene is 1:1, and the mass ratio of methanol to toluene is 1:0.05.

[0050] The reaction yield was 60%, and the content of Z-1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was 95%.

[0051] Comparative Example 2

[0052] The difference from Example 1 is that the reaction temperature is -5°C to -10°C, and the other conditions are the same as those in Example 1, specifically:

[0053] Dissolve 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol in dichloroethane, add sulfuric acid as a catalyst, add thionyl chloride dropwise at 5°C to -10°C, heat and reflux for 1 hour after the addition is completed, wash the oil phase with water, wash with alkali, and desolventize to obtain a crude oily substance, which is then refined by recrystallization from methanol and toluene to obtain a fine product Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0054] The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:1.5.

[0055] The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to sulfuric acid is 1:0.05.

[0056] The mass ratio of crude 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to methanol and toluene is 1:1, and the mass ratio of methanol to toluene is 1:0.05.

[0057] The reaction yield was 61%, and the content of Z-1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was 96%.

[0058] Comparative Example 3

[0059] The difference from Example 1 is that the catalyst is oxalic acid, and the other conditions are the same as those in Example 1, specifically:

[0060]

[0061] Dissolve 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol in dichloroethane, add oxalic acid as a catalyst, add thionyl chloride dropwise at 20°C, heat and reflux for 1 hour after the addition is completed, filter the oil phase, wash with water, wash with alkali, and desolventize to obtain a crude oily substance, which is then purified by recrystallization from methanol and toluene to obtain the fine product Z-3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

[0062] The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:1.5.

[0063] The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to oxalic acid is 1:0.05.

[0064] The mass ratio of crude 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to methanol and toluene is 1:1, and the mass ratio of methanol to toluene is 1:0.05.

[0065] The reaction yield was 36%, and the content of Z-1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol was 95%.

[0066] As can be seen from the above embodiments and comparative examples, the embodiments of the present invention use thionyl chloride as a hydrophilic agent, and at the same time, by controlling a specific reaction temperature and reaction conditions, the selectivity of the product 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene Z body is improved, and the product yield is higher. The waste water generated in the separation process can be used for tail gas absorption of hydrogen chloride and sulfur dioxide, and the tail gas absorption water can be recycled for use of aqueous hydrochloric acid and sodium sulfite for sale, thereby reducing the cost of wastewater treatment. Comparative Example 1 uses conventional acetic anhydride as a hydrophilic agent, and the product selectivity is poor, and acetic anhydride is hydrolyzed to generate acetic acid, and acetic acid is dissolved in water during the product separation process, producing a large amount of high COD wastewater. Comparative Examples 2-3 affect the selectivity of the product 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene Z body due to changes in reaction conditions, and the product yield is reduced.

Claims

1. A method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene, characterized in that: 1-Chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol reacts with thionyl chloride in the presence of a catalyst to generate 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

2. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 1, characterized in that: 1-Chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol is dissolved in a solvent, a catalyst is added, thionyl chloride is added dropwise at 0-80°C, and after the addition is completed, reflux for 1-2 hours to obtain 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

3. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 2, characterized in that: After the reflux, the oil phase is washed with water, washed with alkali, and desolventized to obtain a crude oily substance, which is then refined by recrystallization to obtain 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene.

4. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 2, characterized in that: The catalyst is one or more of sulfuric acid, phosphoric acid, p-toluenesulfonic acid or anhydrous oxalic acid.

5. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 2, characterized in that: The mass ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to the catalyst is 1:0.01 to 1:0.

5.

6. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 2, characterized in that: The molar ratio of 1-chloro-2-(4-chlorophenyl)-3-(2-chlorophenyl)-2-propanol to thionyl chloride is 1:1 to 1:2.

5.

7. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 2, characterized in that: The solvent is one or more of toluene, ether, tetrahydrofuran, dichloroethane, chloroform and dichloromethane.

8. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 3, characterized in that: The recrystallization solvent is one or more of toluene, methanol, ethanol, isopropanol and cyclohexane.

9. The method for synthesizing 3-chloro-2-(4-chlorophenyl)-1-(2-chlorophenyl)-propylene according to claim 3, characterized in that: The mass ratio of the crude oil to the recrystallization solvent is 1:0.3 to 1:2.

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