Catalyst for producing 2, 6-dichlorotoluene and method for catalytically producing 2, 6-dichlorotoluene by applying catalyst
By using a mixed catalyst of aluminum trichloride and tetrachlorobenzene, the synthesis of 2,6-dichlorotoluene was optimized, and the problems of poor catalyst catalytic effect and by-product generation were solved, achieving efficient and economical 2,6 -Dichlorotoluene production improves reaction selectivity and safety.
Patent Information
- Application Number
- CN202411471421.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2024-12-24
AI Technical Summary
The catalyst catalytic effect in the existing 2,6-dichlorotoluene synthesis scheme is poor, resulting in low selectivity and large catalyst usage, and there is a problem of by-product generation.
Using a mixed catalyst of aluminum trichloride and tetrachlorobenzenequinone, the yield of 2,6-dichlorotoluene is improved by adjusting its mass ratio to optimize catalytic activity and selectivity, combined with appropriate reaction conditions and chlorine gas introduction time, and the yield of 2,6-dichlorotoluene and purity, reduce by-product generation.
Under milder conditions, the yield of 2,6-dichlorotoluene is significantly improved, the by-product generation is reduced, the reactant conversion efficiency is improved, the production cost and energy consumption is reduced, and the reaction safety and environmental friendliness are enhanced. .
Smart Images
Figure CN119175112A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of 2,6-dichlorotoluene production, and in particular to a catalyst for 2,6-dichlorotoluene production and a method for catalytically producing 2,6-dichlorotoluene using the catalyst. Background Art
[0002] 2,6-Dichlorotoluene is an important organic raw material intermediate, widely used as a fine chemical intermediate for pesticides, dyes and medicines. 2,6-Dichlorotoluene is used as a raw material to synthesize 2,6-Dichlorobenzaldehyde and 2,6-Dichlorobenzonitrile derivatives. It is used in the pharmaceutical industry to synthesize dicloxacillin sodium, in the pesticide industry to synthesize herbicides dichlorvos and insecticides dichlorvos, and in the dye industry to synthesize the dye acid mordant blue B.
[0003] The synthesis of 2,6-dichlorotoluene in industry usually uses toluene or o-chlorotoluene as the starting material, chlorine gas as the chlorine source, iron powder or Lewis acid such as ferric chloride as the catalyst, and catalytic chlorination under appropriate conditions by introducing a directing group on the benzene ring or adding an auxiliary catalyst to obtain the product. The existing preparation scheme usually uses toluene as the raw material, and produces dichlorotoluene isomers, namely 2,3-dichlorotoluene, 2,4-dichlorotoluene, 2,5-dichlorotoluene, 2,6-dichlorotoluene and 3,4-dichlorotoluene under the catalytic chlorination reaction of the catalyst.
[0004] In view of the above-mentioned prior art, the applicant has found that in the existing synthesis scheme of 2,6-dichlorotoluene, due to the poor catalytic effect of the catalyst, the selectivity of the finally prepared 2,6-dichlorotoluene is low, and there is also the disadvantage of a large amount of catalyst used. Summary of the invention
[0005] Based on the technical problems existing in the above-mentioned prior art, the present invention provides a catalyst for producing 2,6-dichlorotoluene and a method for catalytically producing 2,6-dichlorotoluene using the catalyst.
[0006] In the first aspect, the present application provides a catalyst for the production of 2,6-dichlorotoluene, using the following technical solution: A catalyst for producing 2,6-dichlorotoluene, which is a mixture of aluminum trichloride and tetrachlorobenzoquinone.
[0007] Through the above technical scheme, the present application optimizes the components of the catalyst. By selecting aluminum chloride and tetrachlorobenzoquinone, aluminum chloride, as a strong acid catalyst, can effectively activate the reaction substrate and promote the chlorination reaction. Tetrachlorobenzoquinone can be used as an oxidant to enhance the selectivity and speed of the reaction. The application of this mixed catalyst can improve the yield of 2,6-dichlorotoluene under milder conditions and significantly reduce the formation of by-products. In addition, the composition of the catalyst improves the conversion efficiency of the reactants in the catalytic process, thereby achieving higher economic benefits in industrial production. Such a catalyst formulation not only reduces the energy consumption in the production process, but also improves the safety and environmental friendliness of the reaction.
[0008] Furthermore, the mass ratio of aluminum chloride to tetrachlorobenzoquinone is 1:3-3:1.
[0009] Through the above technical scheme, the present application can further optimize the catalytic activity and selectivity of the catalyst by adjusting the mass ratio, thereby accurately controlling the degree of chlorination during the reaction. Specifically, when the ratio of aluminum chloride is appropriate, the chlorination reaction of o-chlorotoluene can be effectively promoted, and the yield of the target product 2,6-dichlorotoluene can be increased. At the same time, the appropriate addition of tetrachlorobenzoquinone helps to adjust the redox environment of the reaction and further reduce the occurrence of side reactions. Reasonable proportion configuration can not only increase the reaction rate, but also realize the economical use of the catalyst and reduce production costs, which has important industrial application value.
[0010] In a second aspect, the present application provides a method for catalytically producing 2,6-dichlorotoluene, comprising the following technical scheme: A method for catalytically producing 2,6-dichlorotoluene comprises the following technical steps: Take the raw material and the catalyst, mix them and introduce chlorine gas; The preparation of 2,6-dichlorotoluene can be completed by adjusting the temperature in the reaction device and controlling the time of introducing chlorine gas, keeping the temperature to react, collecting dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0011] Through the above technical scheme, the present application clarifies the steps of mixing the raw materials and the catalyst and introducing chlorine, which effectively improves the generation efficiency of 2,6-dichlorotoluene. By adjusting the temperature of the reaction unit and controlling the introduction of chlorine, the reaction process can be accurately grasped to avoid side reactions caused by excessive temperature or excessive chlorine. In addition, the step of heat preservation reaction ensures that the raw materials react under suitable temperature conditions, further improving the selectivity and yield of the reaction. By collecting and separating the isomers of dichlorotoluene, the target product can be efficiently extracted, reducing resource waste, conforming to the concept of green chemistry, and providing a feasible operation process for industrial production.
[0012] Furthermore, the raw material is o-chlorotoluene.
[0013] Through the above technical scheme, the present application selects ortho-chlorotoluene as the starting material for the reaction. Since ortho-chlorotoluene has a suitable molecular structure, it can efficiently carry out chlorination reaction to generate 2,6-dichlorotoluene under the action of a catalyst. The use of ortho-chlorotoluene makes the reaction more selective, can effectively suppress the formation of other isomers, and improve the purity and yield of the target product. In addition, the stability of ortho-chlorotoluene in the production process and the relatively low reaction activation energy further reduce the energy required in the reaction process and reduce production costs. In summary, the choice of ortho-chlorotoluene as a raw material not only optimizes the reaction performance, but also provides a good foundation for industrial large-scale production.
[0014] Furthermore, the addition ratio of the catalyst to the raw material is (0.01-1):100.
[0015] Through the above technical scheme, the present application optimizes the addition ratio of the catalyst and the raw material, and can exert its catalytic effect at a lower dosage, thereby reducing the production cost. While the catalyst accelerates the reaction rate in the reaction, it also ensures the conversion rate of the raw material, thereby increasing the output of 2,6-dichlorotoluene. In addition, a reasonable catalyst addition ratio can reduce the consumption of the catalyst, improve the utilization efficiency of resources, and make the entire reaction process more sustainable. By accurately controlling the amount of catalyst, side reactions caused by excessive catalyst can also be avoided, ensuring the stability of the reaction system and the purity of the product, providing good protection for industrial applications.
[0016] Furthermore, the insulation reaction temperature is 30-50°C.
[0017] Through the above technical scheme, the present application optimizes the reaction temperature. Within this temperature range, the reaction rate is moderate, which is conducive to improving the conversion rate of the reactants, while not causing the deactivation of the catalyst or the occurrence of side reactions. Excessively high temperatures may cause unnecessary side reactions or degradation, so reasonable temperature control is an important measure to ensure a high yield of 2,6-dichlorotoluene. In addition, the reaction conditions within this temperature range help to ensure the safety of the reaction and reduce the potential risks caused by temperature fluctuations, thereby providing a more reliable operating environment for industrial production.
[0018] Furthermore, the time for introducing chlorine gas is 2-6 hours.
[0019] Through the above technical scheme, the present application clarifies the time for passing chlorine, and by adjusting the chlorine passing time, it is possible to ensure that the chlorination reaction is fully carried out, promote the effective contact between the raw material and the chlorine, and thus improve the yield of 2,6-dichlorotoluene. At the same time, controlling the reaction time also helps to avoid side reactions caused by excessive chlorine and ensure the purity of the target compound in the generated product. In industrial applications, a reasonable chlorine passing time can not only improve production efficiency, but also reduce resource waste and further optimize production costs.
[0020] In summary, this application has the following beneficial effects: First, the present application optimizes the components of the catalyst by selecting aluminum chloride and tetrachlorobenzoquinone. Since aluminum chloride is used as a strong acid catalyst, it can effectively activate the reaction substrate and promote the chlorination reaction. Tetrachlorobenzoquinone can be used as an oxidant to enhance the selectivity and speed of the reaction. The application of this mixed catalyst can improve the yield of 2,6-dichlorotoluene under milder conditions and significantly reduce the formation of by-products. In addition, the composition of the catalyst improves the conversion efficiency of the reactants in the catalytic process, thereby achieving higher economic benefits in industrial production. Such a catalyst formulation not only reduces the energy consumption in the production process, but also improves the safety and environmental friendliness of the reaction.
[0021] Second, this application clarifies the steps of mixing the raw materials and the catalyst and introducing chlorine, which effectively improves the generation efficiency of 2,6-dichlorotoluene. By adjusting the temperature of the reaction unit and controlling the introduction of chlorine, the reaction process can be accurately grasped to avoid side reactions caused by excessive temperature or excessive chlorine. In addition, the step of heat preservation reaction ensures that the raw materials react under suitable temperature conditions, further improving the selectivity and yield of the reaction. By collecting and separating the isomers of dichlorotoluene, the target product can be efficiently extracted, reducing resource waste, conforming to the concept of green chemistry, and providing a feasible operation process for industrial production.
[0022] Third, the present application optimizes the addition ratio of catalyst and raw material, and can exert its catalytic effect at a lower dosage, thereby reducing production costs. While the catalyst accelerates the reaction rate in the reaction, it also ensures the conversion rate of the raw material, thereby increasing the output of 2,6-dichlorotoluene. In addition, a reasonable catalyst addition ratio can reduce the consumption of the catalyst, improve the utilization efficiency of resources, and make the entire reaction process more sustainable. By accurately controlling the amount of catalyst, side reactions caused by excessive catalyst can also be avoided, ensuring the stability of the reaction system and the purity of the product, providing good protection for industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a gas chromatogram of the dichlorotoluene isomers prepared in Example 1 of the present application; Figure 2 This is the gas chromatogram of the dichlorotoluene isomers prepared in Example 2 of the present application. DETAILED DESCRIPTION
[0024] The present application is further described in detail below with reference to the embodiments.
[0025] In the examples of the present application, the raw materials and instruments used are as follows, but not limited thereto. Raw materials not otherwise specified are of analytical grade.
[0026] Example 1 A method for preparing 2,6-dichlorotoluene comprises the following steps: Take 20 mg of aluminum chloride and 20 mg of tetrachlorobenzoquinone in a mass ratio of 1:1, and add them into 30 ml of o-chlorotoluene solution at a total mass of the catalyst of 0.13% of the mass of the o-chlorotoluene solution. Slowly and evenly pass chlorine gas for about 3 hours. The temperature during the chlorination process is controlled at 40°C. Samples are taken during the reaction for gas chromatography monitoring.
[0027] The preparation of 2,6-dichlorotoluene can be completed by keeping the reaction warm to collect dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0028] Example 2 A method for preparing 2,6-dichlorotoluene comprises the following steps: Take 20 mg of aluminum chloride and 10 mg of tetrachlorobenzoquinone in a mass ratio of 2:1, and add them into 30 ml of o-chlorotoluene solution at a total mass of the catalyst of 0.1% of the mass of the o-chlorotoluene solution. Pass chlorine gas evenly and slowly for about 3 hours. The temperature during the chlorination process is controlled at 42°C. Samples are taken during the reaction for gas chromatography monitoring.
[0029] The preparation of 2,6-dichlorotoluene can be completed by keeping the reaction warm to collect dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0030] Example 3 A method for preparing 2,6-dichlorotoluene comprises the following steps: Take 10 mg of aluminum chloride and 20 mg of tetrachlorobenzoquinone in a mass ratio of 1:2, and add them to 30 ml of o-chlorotoluene solution at a total mass of the catalyst of 0.1% of the mass of the o-chlorotoluene solution. Slowly and evenly pass chlorine gas for about 3 hours. The temperature during the chlorination process is controlled at 45°C. Samples are taken during the reaction for gas chromatography monitoring.
[0031] The preparation of 2,6-dichlorotoluene can be completed by keeping the reaction warm to collect dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0032] Example 4 A method for preparing 2,6-dichlorotoluene comprises the following steps: Take 20 mg of aluminum chloride and 20 mg of tetrachlorobenzoquinone in a mass ratio of 1:1, and add them into 40 ml of o-chlorotoluene solution at a total mass of the catalyst of 0.1% of the mass of the o-chlorotoluene solution. Pass chlorine gas evenly and slowly for about 3 hours. The temperature during the chlorination process is controlled at 42°C. Samples are taken during the reaction for gas chromatography monitoring.
[0033] The preparation of 2,6-dichlorotoluene can be completed by keeping the reaction warm to collect dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0034] Comparative Example Comparative Example 1 A method for preparing 2,6-dichlorotoluene comprises the following steps: Take 60 mg of aluminum trichloride and add it to 30 ml of o-chlorotoluene solution. Pass chlorine gas evenly and slowly for about 3 hours. The temperature during the chlorine passing process is controlled at 42°C. During the reaction, samples are taken for gas chromatography monitoring.
[0035] The preparation of 2,6-dichlorotoluene can be completed by keeping the reaction warm to collect dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0036] Comparative Example 2 A method for preparing 2,6-dichlorotoluene comprises the following steps: Take 30 mg of iron powder and add it to 30 ml of o-chlorotoluene solution. Pass chlorine gas evenly and slowly for about 3 hours. The temperature during the chlorine passing process is controlled at 42°C. During the reaction, samples are taken for gas chromatography monitoring.
[0037] The preparation of 2,6-dichlorotoluene can be completed by keeping the reaction warm to collect dichlorotoluene isomers and separating 2,6-dichlorotoluene.
[0038] Performance Testing The conversion rate and composition of o-chlorotoluene in the process of preparing 2,6-dichlorotoluene in Example 1-4 and Comparative Example 1-2 were detected by gas chromatography: The results are shown in Table 1 below: Table 1 Performance test table
[0039] From the above examples 1-4 and comparative examples 1-2, combined with the test results in Table 1, it can be found that: This application optimizes the components of the catalyst by selecting aluminum chloride and tetrachlorobenzoquinone. Since aluminum chloride is a strong acid catalyst, it can effectively activate the reaction substrate and promote the chlorination reaction. Tetrachlorobenzoquinone can be used as an oxidant to enhance the selectivity and speed of the reaction. The application of this mixed catalyst can improve the yield of 2,6-dichlorotoluene under milder conditions and significantly reduce the formation of by-products. In addition, the composition of the catalyst improves the conversion efficiency of the reactants in the catalytic process, thereby achieving higher economic benefits in industrial production.
[0040] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.
[0041] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.
[0042] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.
[0043] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.
Claims
1. A catalyst for the production of 2,6-dichlorotoluene, characterized in that: The catalyst is a mixture of aluminum chloride and chloranil.
2. A catalyst for producing 2,6-dichlorotoluene according to claim 1, characterized in that: The mass ratio of aluminum chloride to chlorobenzoquinone is 1:3-3:
1.
3. A method for catalytically producing 2,6-dichlorotoluene according to any one of claims 1 to 2, characterized in that: The following steps are involved: Take the raw material and the catalyst, mix them and introduce chlorine gas; The preparation of 2,6-dichlorotoluene can be completed by adjusting the temperature in the reaction device and controlling the time of introducing chlorine gas, keeping the temperature to react, collecting dichlorotoluene isomers and separating 2,6-dichlorotoluene.
4. A method for catalytically producing 2,6-dichlorotoluene according to claim 3, characterized in that: The raw material is o-chlorotoluene.
5. The method for catalytically producing 2,6-dichlorotoluene according to claim 3, characterized in that: The addition ratio of the catalyst to the raw material is (0.01-1):
100.
6. The method for catalytically producing 2,6-dichlorotoluene according to claim 3, characterized in that: The insulation reaction temperature is 30-50°C.
7. The method for catalytically producing 2,6-dichlorotoluene according to claim 3, characterized in that: The time for introducing chlorine gas is 2-6h.