Synthesis method of 2-ethyl anthrone

Abstract

The invention discloses a synthesis method of 2-ethyl anthrone, which comprises the following steps: (1) adding a catalyst into a reactor, adding a solvent, slowly heating to 70-80 DEG C, stirring and dissolving, the catalyst being tin powder or a mixture of tin powder and a palladium carbon catalyst; (2) introducing nitrogen into the reactor in the step (1) to replace into a nitrogen atmosphere; (3) simultaneously and slowly adding hydrochloric acid and 2-ethyl anthraquinone into the reactor through a charging pump, keeping the reaction temperature between 70 DEG C and 80 DEG C in the charging process, keeping the gauge pressure between 0.01 MPa and 0.08 MPa, and continuing the reaction after the charging is completed; (4) after the reaction is finished, filtering to obtain a reaction solution; and (5) carrying out post-treatment on the reaction liquid obtained in the step (4) to obtain the 2-ethyl anthrone. The synthesis method disclosed by the invention is simple to operate, the used reagents are cheap and easy to obtain, the product purity is high, and the method has relatively good popularization and application values.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen peroxide production, and in particular to a method for synthesizing degradation products in a working solution for producing hydrogen peroxide. Background Art

[0002] Hydrogen peroxide is a colorless, transparent liquid that is miscible with water in any proportion. It can be used for bleaching, three wastes treatment, organic and polymer synthesis, electroplating liquid purification, food industry disinfection, as a surface treatment agent and cleaning agent in the electronics industry, as disinfection in the medical and pharmaceutical industries, and as a rocket propellant.

[0003] With the successful application of hydrogen peroxide in the green process of preparing caprolactam and propylene oxide, the application field of hydrogen peroxide in chemical synthesis has been continuously expanded, and the production efficiency and capacity of the equipment have been greatly improved. In recent years, the annual growth rate of domestic hydrogen peroxide production capacity has been around 10%, and the annual production capacity of a single unit has reached 100,000 to 800,000 tons. The total domestic production capacity has exceeded 15 million tons / year (equivalent to 27.5% hydrogen peroxide).

[0004] The operation of a super-large hydrogen peroxide unit places higher demands on the performance of the working fluid, especially the content of degradation products, which has an important influence on the performance of the working fluid. The content determination of degradation products requires standard substances for accurate quantitative determination. 2-Ethylanthrone, as a degradation product in the working fluid, has a great influence on the performance of the working fluid. Therefore, how to obtain high-purity 2-Ethylanthrone is of great significance for the quantitative determination of the content of degradation products in the working fluid and the judgment of the physical properties of the working fluid. Summary of the invention

[0005] The invention aims to provide a method for synthesizing 2-ethylanthraquinone, which is simple to operate, uses cheap and readily available reagents, has high product purity, and has good promotion and application value.

[0006] The present invention adopts the following technical solution: A method for synthesizing 2-ethylanthraquinone comprises the following steps: (1) adding a catalyst into a reactor, adding a solvent, and slowly heating to 70-80° C. and stirring to dissolve, wherein the catalyst is tin powder or a mixture of tin powder and palladium carbon catalyst; (2) introducing nitrogen into the reactor in step (1) to replace the atmosphere with nitrogen; (3) Slowly adding hydrochloric acid and 2-ethylanthraquinone into the reactor at the same time through a feeding pump, maintaining the reaction temperature between 70 and 80° C. and the gauge pressure between 0.01 and 0.08 MPa during the feeding process, and continuing the reaction after the feeding is completed; (4) After the reaction is completed, filter to obtain the reaction solution; (5) The reaction solution obtained in step (4) is post-treated to obtain 2-ethylanthrone.

[0007] Furthermore, when the catalyst in step (1) is tin powder, the mass of the catalyst is 65% to 85% of the mass of 2-ethylanthraquinone; when the catalyst is a mixture of tin powder and palladium-carbon catalyst, the mass of the catalyst is 30% to 50% of the mass of 2-ethylanthraquinone, wherein the mass of tin powder accounts for 50 to 70% of the total mass of tin powder and palladium-carbon catalyst. When the catalyst is a mixture of tin powder and palladium-carbon catalyst, although the catalyst price is relatively high, the palladium-carbon catalyst can be reused more than 50 times; when the catalyst is tin powder, the cost is relatively low, but it is a one-time consumption.

[0008] Furthermore, in step (1), the solvent is one of ethanol, isopropanol and butanol, and the amount of solvent added is 5 to 8 times the mass of 2-ethylanthraquinone.

[0009] Furthermore, in step (1), the purity of the tin powder is greater than 99%, and the palladium content in the palladium carbon catalyst is between 5% and 12%.

[0010] Furthermore, in step (3), the purity of 2-ethylanthraquinone is greater than 99%, the concentration of hydrochloric acid is 36% to 37%, and the amount of hydrochloric acid added is 1.5 to 2.5 times the mass of 2-ethylanthraquinone.

[0011] Furthermore, in step (3), the addition time is 1 to 2 hours, and the reaction is continued for 2 to 3 hours after the addition is completed.

[0012] Furthermore, in step (1), when the catalyst is a mixture of tin powder and palladium-carbon catalyst, the wet palladium-carbon catalyst can be obtained by filtering in step (4), and can be reused after drying.

[0013] Furthermore, in step (5), the post-treatment includes: removing the solvent under reduced pressure, washing, and low-temperature reduced pressure drying. The obtained solvent can be recycled and reused.

[0014] Furthermore, in step (5), 2-ethylanthraquinone includes 2-ethyl-10-anthraquinone and 2-ethyl-9-anthraquinone, and the purity of the sum of the two is greater than 99%.

[0015] Furthermore, in step (5), the storage method of 2-ethylanthrone is to replace the sample bottle with nitrogen and store it at low temperature. Because 2-ethylanthrone is easily oxidized in the air, it must be stored in a low-temperature nitrogen atmosphere and can be stored for more than 1 year without significant reduction in purity.

[0016] By adopting the preparation method of the present invention, the purity of the prepared 2-ethylanthraquinone is greater than 99%, the yield is greater than 95%, and the prepared product can be used as a standard sample of anthraquinone degradation products. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with embodiments. The present invention is not limited to the embodiments. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0018] Example 1 A method for synthesizing 2-ethylanthraquinone comprises the following steps: (1) Add 11 g of 99.2% pure tin powder into a reactor, add 83 g of ethanol, and slowly heat to 70-80 °C and stir to dissolve; (2) introducing nitrogen into the reactor in step (1) to replace the atmosphere with nitrogen; (3) 27 g of 37% hydrochloric acid and 16.5 g of 2-ethylanthraquinone were slowly added to the above reactor at the same time through a feeding pump, and the gauge pressure was maintained at 0.01 MPa. During the feeding process, the reaction temperature was maintained between 70 and 80 °C. The feeding time was 2 hours. After the feeding was completed, the reaction was continued for 3 hours; (4) After the reaction is completed, the temperature is naturally lowered and filtered to obtain the reaction solution; (5) The reaction solution obtained in step (4) is subjected to reduced pressure to remove the solvent, washed, and dried under reduced pressure at low temperature to obtain 2-ethylanthrone with a purity of 99.1% and a yield of 96%. The solvent can be recycled and reused. The 2-ethylanthrone is placed in a sample bottle and filled with nitrogen. It can be stored at -5 to 5°C for more than one year without a significant decrease in purity.

[0019] Example 2 A method for synthesizing 2-ethylanthraquinone comprises the following steps: (1) Add 14 g of 99.2% pure tin powder into a reactor, add 130 g of ethanol, and slowly heat to 70-80 °C and stir to dissolve; (2) introducing nitrogen into the reactor in step (1) to replace the atmosphere with nitrogen; (3) 38 g of 36% hydrochloric acid and 16.5 g of 99.2% pure 2-ethylanthraquinone were slowly added to the above reactor simultaneously through a feeding pump. During the feeding process, the reaction temperature was maintained between 70 and 80 °C, and the gauge pressure was maintained at 0.05 MPa. The feeding time was 1.8 h. After the feeding was completed, the reaction was continued for 2.5 h. (4) After the reaction is completed, the temperature is naturally lowered and filtered to obtain the reaction solution; (5) The reaction solution obtained in step (4) is subjected to reduced pressure to remove the solvent, washed, and dried under reduced pressure at low temperature to obtain 2-ethylanthrone with a purity of 99.4% and a yield of 97.2%. The solvent can be recycled and reused. The 2-ethylanthrone is placed in a sample bottle and filled with nitrogen. It can be stored at -5 to 5°C for more than one year without a significant decrease in purity.

[0020] Example 3 A method for synthesizing 2-ethylanthraquinone comprises the following steps: (1) Add 5.5 g of a mixture of tin powder and palladium-carbon catalyst into a reactor, add 84 g of ethanol, and slowly heat to 70-80 °C and stir to dissolve, wherein the mass of tin powder accounts for 65% of the total mass of tin powder and palladium-carbon catalyst; (2) introducing nitrogen into the reactor in step (1) to replace the atmosphere with nitrogen; (3) 30 g of 37% hydrochloric acid and 16.5 g of 2-ethylanthraquinone were slowly added to the above reactor simultaneously through a feeding pump. During the feeding process, the reaction temperature was maintained between 70 and 80 °C, and the gauge pressure was maintained at 0.02 MPa. The feeding time was 2 h. After the feeding was completed, the reaction was continued for 3 h. (4) After the reaction is completed, the temperature is naturally lowered and filtered to obtain the reaction solution; (5) The reaction solution obtained in step (4) is subjected to reduced pressure to remove the solvent, washed, and dried under reduced pressure at low temperature to obtain 2-ethylanthrone with a purity of 99.3% and a yield of 98.3%. The solvent can be recycled and reused. The 2-ethylanthrone is placed in a sample bottle and filled with nitrogen. It can be stored at -5 to 5°C for more than one year without a significant decrease in purity.

[0021] Example 4 A method for synthesizing 2-ethylanthraquinone comprises the following steps: (1) Add 6.5 g of a mixture of tin powder and palladium-carbon catalyst into a reactor, add 130 g of ethanol, and slowly heat to 70-80 °C and stir to dissolve, wherein the mass of tin powder accounts for 65% of the total mass of tin powder and palladium-carbon catalyst; (2) introducing nitrogen into the reactor in step (1) to replace the atmosphere with nitrogen; (3) 38 g of 36% hydrochloric acid and 16.5 g of 99.5% pure 2-ethylanthraquinone were slowly added to the above reactor simultaneously through a feeding pump. During the feeding process, the reaction temperature was maintained between 70 and 80 °C, and the gauge pressure was maintained at 0.08 MPa. The feeding time was 1 hour. After the feeding was completed, the reaction was continued for 2 hours; (4) After the reaction is completed, the temperature is naturally lowered and filtered to obtain the reaction solution; (5) The reaction solution obtained in step (4) is subjected to reduced pressure to remove the solvent, washed, and dried under reduced pressure at low temperature to obtain 2-ethylanthrone with a purity of 99.6% and a yield of 98.9%. The solvent can be recycled and reused. The 2-ethylanthrone is placed in a sample bottle and filled with nitrogen. It can be stored at -5 to 5°C for more than one year without a significant decrease in purity.

[0022] Comparative Example 1 The difference between Comparative Example 1 and Example 4 is that the gauge pressure in step (3) is 0 MPa, and the rest is the same as Example 4 and will not be repeated; the product purity in the final step (4) is 78.4% and the yield is 96.1%, indicating that when tin powder and palladium carbon catalyst are used, the reaction is incomplete without pressure and the product purity is low.

[0023] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that the gauge pressure in step (3) is 0 MPa, and the rest is the same as in Example 2 and will not be repeated; the purity of the product in the final step (4) is 89.2% and the yield is 95.2%. This indicates that when using tin powder, the pressure has an effect on the reaction but it is not significant.

[0024] Comparative Example 3 The difference between Comparative Example 3 and Example 4 is that in step (5), the sample bottle is not filled with nitrogen and is stored at room temperature. The rest is the same as Example 4 and will not be repeated. After two months of storage, the purity is reduced to 81.2%.

[0025] Comparative Example 4 The difference between Comparative Example 1 and Example 4 is that the gauge pressure in step (3) is 0.3 MPa, and the rest is the same as Example 4 and will not be repeated; the product purity in the final step (4) is 50.2%, and the yield is 94.3%, indicating that when tin powder and palladium carbon catalyst are used, the pressure is too high, and more other by-products are generated by hydrogenation, resulting in a significant decrease in product purity.

[0026] Comparative Example 5 The difference between Comparative Example 1 and Example 4 is that 16.5 g of 99.5% pure 2-ethylanthraquinone is added in step 1 at one time, and the rest is the same as Example 4 and will not be repeated; the purity in the final step (4) is 93.1% and the yield is 91.2%, indicating that the slow addition of 2-ethylanthraquinone is more conducive to the reaction proceeding in the forward direction and the yield is higher.

Claims

1. A method for synthesizing 2-ethylanthraquinone, The following steps are involved: (1) adding a catalyst into a reactor, adding a solvent, and slowly heating to 70-80° C. and stirring to dissolve, wherein the catalyst is tin powder or a mixture of tin powder and palladium carbon catalyst; (2) introducing nitrogen into the reactor in step (1) to replace the atmosphere with nitrogen; (3) Slowly adding hydrochloric acid and 2-ethylanthraquinone into the reactor at the same time through a feeding pump, maintaining the reaction temperature between 70 and 80° C. and the gauge pressure between 0.01 and 0.08 MPa during the feeding process, and continuing the reaction after the feeding is completed; (4) After the reaction is completed, filter to obtain the reaction solution; (5) The reaction solution obtained in step (4) is post-treated to obtain 2-ethylanthrone.

2. The synthesis method according to claim 1, It is characterized in that When the catalyst in step (1) is tin powder, the mass of the catalyst is 65% to 85% of the mass of 2-ethylanthraquinone; when the catalyst is a mixture of tin powder and palladium-carbon catalyst, the mass of the catalyst is 30% to 50% of the mass of 2-ethylanthraquinone, wherein the mass of the tin powder accounts for 50 to 70% of the total mass of the tin powder and the palladium-carbon catalyst.

3. The synthesis method according to claim 1, It is characterized in that In step (1), the solvent is one of ethanol, isopropanol and butanol.

4. The synthesis method according to claim 1, It is characterized in that In step (1), the amount of solvent added is 5 to 8 times the mass of 2-ethylanthraquinone.

5. The synthesis method according to claim 1, It is characterized in that When the catalyst in step (1) is a mixture of tin powder and palladium-carbon catalyst, the wet palladium-carbon catalyst can be obtained by filtering in step (4), which can be dried and reused.

6. The synthesis method according to claim 1, It is characterized in that In step (1), the purity of the tin powder is greater than 99%, and the palladium content in the palladium-carbon catalyst is between 5% and 12%.

7. The synthesis method according to claim 1, It is characterized in that The amount of hydrochloric acid added is 1.5 to 2.5 times the mass of 2-ethylanthraquinone.

8. The synthesis method according to claim 1, It is characterized in that In step (5), the post-treatment includes: removing the solvent under reduced pressure, washing, and low-temperature reduced pressure drying.

9. The synthesis method according to claim 1, It is characterized in that The purity of 2-ethylanthrone is >99%.

10. The synthesis method according to claim 1, It is characterized in that The storage method of 2-ethylanthrone is to replace the sample bottle with nitrogen and store it at low temperature.