Method for efficiently preparing 1, 3-cyclohexanedione through selective hydrogenation

Abstract

The invention relates to the technical field of organic synthesis, and provides a method for efficiently preparing 1, 3-cyclohexanedione through selective hydrogenation, which comprises the following steps: preparing hexagonal mesoporous silicon oxide by taking tetraethoxysilane as a silicon source and dodecylamine as a structure-directing agent, compounding the hexagonal mesoporous silicon oxide with titanium oxide to obtain a carrier, and taking palladium as a catalytic active component to prepare a catalyst I; preparing a copper-based coordination polymer by taking copper chloride dihydrate and phenylacetylene as raw materials; preparing a catalyst II by taking nickel as a catalytic active component; the method comprises the following steps: reacting resorcinol with hydrogen under the combined action of alkali, water, a catalyst I and a catalyst II, and then acidizing and recrystallizing to obtain the target product 1, 3-cyclohexanedione. According to the method, resorcinol is taken as a raw material, the self-made catalyst I and the self-made catalyst II are adopted for concerted catalytic hydrogenation, 1, 3-cyclohexanone with relatively high purity is prepared, and the catalysts are high in catalytic activity, easy to separate and still have very good catalytic performance after being recycled for multiple times.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation. Background Art

[0002] 1,3-Cyclohexanedione is an important chemical intermediate that is widely used in the synthesis of drugs and pesticides and has important research significance and commercial value.

[0003] At present, the synthesis routes of 1,3-cyclohexanedione mainly include γ-acetobutyrate condensation method and resorcinol reduction method. γ-acetobutyrate condensation method uses γ-acyl carboxylic acid ester as raw material and strong base as condensation agent to condense and cyclize to generate 1,3-cyclohexanedione; resorcinol reduction method uses resorcinol as raw material, hydrogen, formate and isopropanol as hydrogen donors, and precious metals or Ni as catalysts to reduce the raw materials to 1,3-cyclohexanedione. In the above methods, γ-acetobutyric acid methyl ester is not easy to obtain and the reaction conditions are harsh, while the resorcinol reduction method has the characteristics of simple method, high product yield, easy separation and stable quality, and is currently the mainstream method for producing 1,3-cyclohexanedione.

[0004] Patent application number 201510616238.1 provides a method for preparing 1,3-cyclohexanedione, comprising the following steps: (1) fully stirring 90-95 parts of resorcinol, 5-10 parts of sodium hydroxide solution, and 10-20 parts of deionized water; (2) placing the stirred resorcinol solution into a pressure vessel, and heating the pressure vessel; (3) adding 10-15 parts of a catalyst to the heated and pressure-maintained resorcinol solution, stirring for 10-15 minutes, reacting for 15-20 hours, and obtaining a black solid after the metal ions in the solution are completely reduced; (4) washing the black solid with distilled water, and then washing with ethanol, and finally placing the product in ethanol to obtain a finished product; the catalyst is a mixture of lanthanum chloride and palladium dichloride. Although the above method can effectively improve the purity of the target product, the amount of catalyst used is large, and the catalyst stability needs to be further improved. It is not easy to recover and has poor recycling performance. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, a method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation is provided. The method uses resorcinol as a raw material and adopts a self-made catalyst one and a catalyst two for coordinated catalytic hydrogenation to prepare 1,3-cyclohexanone with high purity. The catalyst has high catalytic activity, is easy to separate, and still has good catalytic performance after being recycled for multiple times.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: A method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation comprises the following steps: S1: Preparation of Catalyst 1: Under vigorous stirring, ethyl orthosilicate is embedded in a mixed solution of dodecylamine, ethanol and deionized water, and then aged. The reaction solution is filtered, the precipitate is dried and calcined to obtain hexagonal mesoporous silica, the hexagonal mesoporous silica and titanium oxide are mixed and added to a palladium chloride solution and stirred, sodium hydroxide solution is added to adjust the pH of the reaction solution, stirred until no new precipitate is generated, filtered, the precipitate is added to hydrazine hydrate, mixed and stirred for reaction, and finally centrifuged, and the precipitate after centrifugation is dried to obtain catalyst one; S2: Preparation of Catalyst 2: Dissolve cupric chloride dihydrate in ammonia monohydrate, add hydroxylamine hydrochloride, stir and mix, then add phenylacetylene, seal and stir until no new precipitate is generated, then centrifuge the reaction solution, wash the centrifugal precipitate and dry it to obtain a copper-based coordination polymer; disperse the copper-based coordination polymer in deionized water to obtain a dispersion; add nickel nitrate hexahydrate solution to the dispersion, stir and react, then centrifuge, wash the centrifugal precipitate and dry it to obtain catalyst 2; S3: Catalytic hydrogenation: Under the combined action of alkali, water, catalyst one and catalyst two, resorcinol reacts with hydrogen, and then undergoes acidification and recrystallization to obtain the target product 1,3-cyclohexanedione.

[0007] Preferably, in step S1, the mass ratio of dodecylamine, ethanol, deionized water and tetraethyl orthosilicate is 10: (80-90): (50-60): (40-45); and / or the temperature of the aging treatment is room temperature and the time is 10-20 hours; and / or the conditions of the calcination treatment are: heating to 500°C at a rate of 5-10°C / min and calcining for 3-5 hours.

[0008] Preferably, in step S1, the titanium oxide is anatase titanium oxide, and the average particle size of the titanium oxide is 10-20 nm; the mass ratio of the hexagonal mesoporous silica, titanium oxide, and palladium chloride is 1:(1-3):(0.04-0.05).

[0009] Preferably, in step S1, the stirring treatment time is 1-2h; the concentration of the sodium hydroxide solution is 1 mol / L, the pH of the reaction solution is adjusted to 10-11, the molar ratio of hydrazine hydrate to palladium chloride is (8-10):1; the temperature of the mixed stirring reaction is room temperature, and the time is 2-5h.

[0010] Preferably, in step S2, the usage ratio of cupric chloride dihydrate, ammonia monohydrate, hydroxylamine hydrochloride and phenylacetylene is 1 mmol: (30-50) ml: (1-2) mmol: 1 ml; and / or the stirring speed of the sealed stirring treatment is 2000-3000 rpm, and the temperature is room temperature.

[0011] Preferably, in step S2, the mass ratio of the copper-based coordination polymer to nickel nitrate hexahydrate is (3-4):1; and / or the stirring reaction is carried out at room temperature for 1-5 hours.

[0012] Preferably, in step S3, the base is sodium hydroxide, and the mass ratio of resorcinol, sodium hydroxide, water, catalyst one, and catalyst two is 110: (40-50): (300-400): (0.1-0.2): (0.1-0.2).

[0013] Preferably, in step S3, the reaction temperature is 20-40°C, the reaction pressure is 0.5-1.5 MPa, and the reaction time is 0.5-1h; during acidification, hydrochloric acid is used to adjust the pH of the filtrate to 2-2.5, and the temperature during acidification is 5-10°C and the time is 0.5-1.5h.

[0014] Preferably, in step S3, the recrystallization treatment is to perform a primary crystallization treatment on the acidified filtrate, filter to obtain solid one and filtrate one, mix and stir the filtrate one and the recrystallization solvent, let it stand for treatment, and dry the organic phase to obtain solid two; dissolve solid one and solid two and the recrystallization solvent again in the recrystallization solvent, perform a secondary crystallization treatment, filter, and dry the filter cake to obtain the target product.

[0015] Preferably, in step S3, the temperature of the primary crystallization treatment and the secondary crystallization treatment are both 0-5°C, and the time is both 3-5h; and / or the recrystallization solvent is a mixture of dichloromethane and acetonitrile, and the volume ratio of the two is 1:1.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention adopts self-made catalyst 1 and catalyst 2 for synergistic catalytic reaction, and adopts nickel-based catalyst to replace part of palladium-based catalyst, which not only reduces the cost of catalyst, but also significantly improves the conversion rate of m-diphenol and the selectivity of 1,3-cyclohexanedione.

[0017] 2. The present invention uses self-made hexagonal mesoporous silica and titanium oxide as composite carriers, and palladium as the catalytic active component to prepare a supported catalyst. Hexagonal mesoporous silica has a high surface area and a uniform pore size distribution, which can achieve uniform dispersion of palladium active components and prevent palladium particles from aggregating. The presence of surface defects in nano-titanium oxide is conducive to the anchoring of Pd clusters on the carrier surface, resulting in an enhanced strong electronic metal-carrier interaction between the carrier and palladium, which not only enhances the catalytic activity, but also improves the selectivity of the target product. The mesoporous structure of hexagonal mesoporous silica can also selectively adsorb, so that the raw materials are adsorbed on the catalyst surface, thereby improving production efficiency.

[0018] 3. The catalyst 2 of the present invention uses a copper-based coordination polymer as a carrier and nickel as a catalytically active component. The metal-organic interface between the carrier and the catalytically active component can effectively adjust the electronic state of nickel, making it electron-deficient, thereby reducing the adsorption weakening of 1,3-cyclohexanedione on the catalyst, preventing excessive hydrogenation, and improving the selectivity of the product. DETAILED DESCRIPTION

[0019] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0020] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] In the following examples and comparative examples, unless otherwise specified, the raw materials are all commercially available and the conditions are all conventional conditions in the art. Example 1

[0022] A method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation comprises the following steps: (1) Preparation of Catalyst 1: Dodecylamine, ethanol and deionized water were mixed and stirred in a mass ratio of 10:80:50 to obtain a mixed solution. Ethyl orthosilicate (the amount added was 4 times the mass of dodecylamine) was added to the mixed solution under vigorous stirring, and then aged at room temperature for 12 hours. After the aging, the reaction solution was filtered, and the filter cake was dried at 60°C and placed in a muffle furnace. The temperature was raised to 500°C at a rate of 5°C / min in an air atmosphere and calcined for 3 hours to obtain hexagonal mesoporous silica. 0.04g of palladium chloride was dissolved in 50ml of deionized water. to obtain a palladium chloride solution, 1g of hexagonal mesoporous silica and 1g of titanium oxide (anatase, with an average particle size of 10nm) were mixed and added to the palladium chloride solution, stirred for 1h, 1mol / L sodium hydroxide solution was added to adjust the pH of the solution to 11, stirred until no new precipitate was generated, filtered, and the precipitate was added to a 50wt% hydrazine hydrate solution (the molar ratio of palladium chloride to hydrazine hydrate was 1:8), mixed and stirred at room temperature for 3h, and finally centrifuged, and the precipitate after centrifugation was dried to obtain a catalyst 1; (2) Preparation of Catalyst 2: Dissolve 1mmol of cupric chloride dihydrate in 30ml of ammonia monohydrate, add 1.5mmol of hydroxylamine hydrochloride, stir and mix, then add 1ml of phenylacetylene, and stir in a sealed manner at 2000rpm until no new precipitate is generated, then centrifuge the reaction solution, wash the centrifugal precipitate and dry it to obtain a copper-based coordination polymer; disperse 3g of the copper-based coordination polymer in 100ml of deionized water to obtain a dispersion; dissolve 1g of nickel nitrate hexahydrate in 100ml of deionized water to obtain a nickel nitrate hexahydrate solution, mix the above dispersion and the nickel nitrate hexahydrate solution, stir and react at room temperature for 2h, then centrifuge, wash the centrifugal precipitate and dry it to obtain catalyst 2; (3) Catalytic hydrogenation: 110.0g of resorcinol, 44.5g of sodium hydroxide, 320g of water, 0.1g of catalyst 1 and 0.1g of catalyst 2 were added into a reactor, nitrogen was introduced into the reactor to replace the air, the temperature was raised to 40°C, hydrogen was introduced into the reactor, the pressure in the reactor was maintained at 1MPa, and the reaction was kept warm for 1h. After the reaction, the reaction solution was filtered to remove the catalyst, the filtrate was cooled to room temperature, hydrochloric acid was added to adjust the pH of the solution to 2, and the solution was treated at 5°C for 1h; the acidified solution was cooled to 2°C and treated for 4h; filtered to obtain solid 1 and filtrate 1, the filtrate 1 and a recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1) were mixed and stirred, and then allowed to stand for treatment, and the organic phase was dried to obtain solid 2; solid 1 and solid 2 were dissolved again in a recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1), secondary crystallization was carried out at 2°C for 3h, filtered, and the filter cake was dried to obtain the target product. Example 2

[0023] A method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation comprises the following steps: (1) Preparation of Catalyst 1: Dodecylamine, ethanol and deionized water were mixed and stirred in a mass ratio of 10:85:50 to obtain a mixed solution. Tetraethyl orthosilicate (the amount added was 4 times the mass of dodecylamine) was added to the mixed solution under vigorous stirring, and then aged at room temperature for 15 hours. After the aging, the reaction solution was filtered, and the filter cake was dried at 60°C and placed in a muffle furnace. The temperature was raised to 500°C at a rate of 7°C / min in an air atmosphere and calcined for 4 hours to obtain hexagonal mesoporous silica. 0.045g of palladium chloride was dissolved in 50ml of deionized water. A palladium chloride solution is obtained, 1g of hexagonal mesoporous silica and 1g of titanium oxide (anatase, with an average particle size of 10nm) are mixed and added to the palladium chloride solution, and the mixture is stirred for 1.5h. A 1mol / L sodium hydroxide solution is added to adjust the pH of the solution to 11, and the mixture is stirred until no new precipitation is generated, and the mixture is filtered. The precipitation is added to a 50wt% hydrazine hydrate solution (the molar ratio of palladium chloride to hydrazine hydrate is 1:9), and the mixture is stirred and reacted at room temperature for 4h. The mixture is centrifuged and the precipitation after centrifugation is dried to obtain a catalyst 1. (2) Preparation of Catalyst 2: Dissolve 1mmol of cupric chloride dihydrate in 40ml of ammonia monohydrate, add 1.5mmol of hydroxylamine hydrochloride, stir and mix, then add 1ml of phenylacetylene, and stir in a sealed manner at 2500rpm until no new precipitate is generated, then centrifuge the reaction solution, wash the centrifugal precipitate and dry it to obtain a copper-based coordination polymer; disperse 3.5g of the copper-based coordination polymer in 100ml of deionized water to obtain a dispersion; dissolve 1g of nickel nitrate hexahydrate in 100ml of deionized water to obtain a nickel nitrate hexahydrate solution, mix the above dispersion and the nickel nitrate hexahydrate solution, stir and react at room temperature for 2h, then centrifuge, wash the centrifugal precipitate and dry it to obtain catalyst 2; (3) Catalytic hydrogenation: 110.0g of resorcinol, 44.5g of sodium hydroxide, 320g of water, 0.1g of catalyst 1 and 0.15g of catalyst 2 were added into a reactor, nitrogen was introduced into the reactor to replace the air, the temperature was raised to 40°C, hydrogen was introduced into the reactor, the pressure in the reactor was maintained at 1.2MPa, and the reaction was kept warm for 1h. After the reaction was completed, the reaction solution was filtered to remove the catalyst, the filtrate was cooled to room temperature, hydrochloric acid was added to adjust the pH of the solution to 2.2, and the reaction mixture was stirred at 80°C for 24 hours. ℃ for 1h; the acidified solution is cooled to 3℃ and treated for 5h; filtered to obtain solid 1 and filtrate 1, the filtrate 1 and the recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1) are mixed and stirred, and then allowed to stand for treatment, and the organic phase is dried to obtain solid 2; solid 1 and solid 2 are dissolved again in a recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1), and secondary crystallization is carried out at 3℃ for 5h, filtered, and the filter cake is dried to obtain the target product. Example 3

[0024] A method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation comprises the following steps: (1) Preparation of Catalyst 1: Dodecylamine, ethanol and deionized water were mixed and stirred in a mass ratio of 10:90:55 to obtain a mixed solution. Tetraethyl orthosilicate (the amount added was 4 times the mass of dodecylamine) was added to the mixed solution under vigorous stirring, and then aged at room temperature for 18 hours. After the aging, the reaction solution was filtered, and the filter cake was dried at 60°C and placed in a muffle furnace. The temperature was raised to 500°C at a rate of 10°C / min in an air atmosphere and calcined for 4 hours to obtain hexagonal mesoporous silica. 0.04g of palladium chloride was dissolved in 50ml of deionized water. , obtain a palladium chloride solution, mix 1g of hexagonal mesoporous silica and 3g of titanium oxide (anatase, with an average particle size of 10nm), add the mixture to the palladium chloride solution, and stir for 1h, add a 1mol / L sodium hydroxide solution to adjust the pH of the solution to 11, stir until no new precipitate is generated, filter, add the precipitate to a 50wt% hydrazine hydrate solution (the molar ratio of palladium chloride to hydrazine hydrate is 1:9.5), mix and stir at room temperature for 4.5h, and finally centrifuge, and dry the precipitate after centrifugation to obtain catalyst 1; (2) Preparation of Catalyst 2: Dissolve 1mmol of cupric chloride dihydrate in 50ml of ammonia monohydrate, add 2mmol of hydroxylamine hydrochloride, stir and mix, then add 1ml of phenylacetylene, and stir in a sealed manner at 3000rpm until no new precipitate is generated, then centrifuge the reaction solution, wash the centrifugal precipitate and dry it to obtain a copper-based coordination polymer; disperse 3.5g of the copper-based coordination polymer in 100ml of deionized water to obtain a dispersion; dissolve 1g of nickel nitrate hexahydrate in 100ml of deionized water to obtain a nickel nitrate hexahydrate solution, mix the above dispersion and the nickel nitrate hexahydrate solution, stir and react at room temperature for 3h, then centrifuge, wash the centrifugal precipitate and dry it to obtain catalyst 2; (3) Catalytic hydrogenation: 110.0g of resorcinol, 44.5g of sodium hydroxide, 320g of water, 0.1g of catalyst 1 and 0.2g of catalyst 2 were added into the reactor, nitrogen was introduced into the reactor to replace the air, the temperature was raised to 40°C, hydrogen was introduced into the reactor, the pressure in the reactor was maintained at 1.0MPa, and the reaction was kept warm for 1h. After the reaction was completed, the reaction solution was filtered to remove the catalyst, the filtrate was cooled to room temperature, hydrochloric acid was added to adjust the pH of the solution to 2, and the reaction mixture was heated at 7°C. The mixture was stirred for 1.5 hours and the acidified solution was cooled to 1°C and treated for 4 hours. The solid 1 and the filtrate 1 were obtained. The filtrate 1 and the recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1) were mixed and stirred, and then allowed to stand for treatment. The organic phase was dried to obtain the solid 2. The solid 1 and the solid 2 were dissolved again in the recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1), and secondary crystallization was carried out at 2°C for 4 hours. The mixture was filtered and the filter cake was dried to obtain the target product. Example 4

[0025] A method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation comprises the following steps: (1) Preparation of Catalyst 1: Dodecylamine, ethanol and deionized water were mixed and stirred in a mass ratio of 10:85:60 to obtain a mixed solution. Ethyl orthosilicate (the amount added was 4.5 times the mass of dodecylamine) was added to the mixed solution under vigorous stirring, and then aged at room temperature for 15 hours. After the aging, the reaction solution was filtered, and the filter cake was dried at 60°C and placed in a muffle furnace. The temperature was raised to 500°C at a rate of 7°C / min in an air atmosphere and calcined for 5 hours to obtain hexagonal mesoporous silica. 0.05g of palladium chloride was dissolved in 50ml of deionized water. water, to obtain a palladium chloride solution, 1g of hexagonal mesoporous silica and 3g of titanium oxide (anatase, with an average particle size of 10nm) were mixed and added to the palladium chloride solution, stirred for 2h, 1mol / L sodium hydroxide solution was added to adjust the pH of the solution to 11, stirred until no new precipitate was generated, filtered, and the precipitate was added to a 50wt% hydrazine hydrate solution (the molar ratio of palladium chloride to hydrazine hydrate was 1:10), mixed and stirred at room temperature for 5h, and finally centrifuged, and the precipitate after centrifugation was dried to obtain catalyst 1; (2) Preparation of Catalyst 2: Dissolve 1mmol of cupric chloride dihydrate in 50ml of ammonia monohydrate, add 1.5mmol of hydroxylamine hydrochloride, stir and mix, then add 1ml of phenylacetylene, and stir in a sealed manner at 3000rpm until no new precipitate is generated, then centrifuge the reaction solution, wash the centrifugal precipitate and dry it to obtain a copper-based coordination polymer; disperse 3g of the copper-based coordination polymer in 100ml of deionized water to obtain a dispersion; dissolve 1g of nickel nitrate hexahydrate in 100ml of deionized water to obtain a nickel nitrate hexahydrate solution, mix the above dispersion and the nickel nitrate hexahydrate solution, stir and react at room temperature for 5h, then centrifuge, wash the centrifugal precipitate and dry it to obtain catalyst 2; (3) Catalytic hydrogenation: 110.0g, 44.5g of sodium hydroxide, 320g of water, 0.2g of catalyst 1 and 0.1g of catalyst 2 were added to a reactor, nitrogen was introduced into the reactor to replace the air, the temperature was raised to 40°C, and then hydrogen was introduced into the reactor, the pressure in the reactor was maintained at 0.9MPa, and the reaction was kept warm for 1h. After the reaction, the reaction solution was filtered to remove the catalyst, and the filtrate was cooled to room temperature, and hydrochloric acid was added to adjust the pH of the solution to 2, and the solution was treated at 5°C for 1.5h; the acidified solution was cooled to 0°C and treated for 5h; filtered to obtain solid 1 and filtrate 1, the filtrate 1 and a recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1) were mixed and stirred, and then allowed to stand for treatment, and the organic phase was dried to obtain solid 2; solid 1 and solid 2 were dissolved again in a recrystallization solvent (mixed with dichloromethane and acetonitrile in a volume ratio of 1:1), and secondary crystallization was carried out at 0°C for 3h, filtered, and the filter cake was dried to obtain the target product.

[0026] In order to verify the effect of the present invention, the following is a detailed description with reference to Example 4 and combined with a plurality of comparative examples.

[0027] Comparative Example 1 Compared with Example 4, the difference is that only Catalyst 1 is added during the catalytic hydrogenation in step (3).

[0028] Comparative Example 2 Compared with Example 4, the difference is that only Catalyst 2 is added during the catalytic hydrogenation in step (3).

[0029] Comparative Example 3 Compared with Example 4, the difference is that in step (1), an equal amount of spherical silica in the prior art is used to replace the hexagonal mesoporous silica in Example 4.

[0030] Comparative Example 4 Compared with Example 4, the difference is that in step (1), the carrier only uses hexagonal mesoporous silica.

[0031] Comparative Example 5 Compared with Example 4, the difference is that in step (1), the carrier is only titanium oxide.

[0032] Comparative Example 6 Compared with Example 4, the difference is that in step (1), hexagonal mesoporous silica and titanium oxide are not used as carriers.

[0033] Comparative Example 7 Compared with Example 4, the difference is that in step (2), the copper-based coordination polymer is not used as a carrier.

[0034] After testing, the raw material conversion rate and product selectivity in the above embodiments and comparative examples are shown in Table 1.

[0035] Table 1

[0036] It can be seen from the above test results that, compared with the comparative example, the present invention uses self-made catalyst 1 and catalyst 2 to coordinate the catalytic reaction, which effectively improves the conversion rate of m-diphenol and the selectivity of 1,3-cyclohexanedione at a lower catalyst dosage.

[0037] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation, characterized in that: The following steps are involved: S1: Preparation of Catalyst 1: Under vigorous stirring, ethyl orthosilicate is embedded in a mixed solution of dodecylamine, ethanol and deionized water, and then aged. The reaction solution is filtered, the precipitate is dried and calcined to obtain hexagonal mesoporous silica, the hexagonal mesoporous silica and titanium oxide are mixed and added to a palladium chloride solution and stirred, sodium hydroxide solution is added to adjust the pH of the reaction solution, stirred until no new precipitate is generated, filtered, the precipitate is added to hydrazine hydrate, mixed and stirred for reaction, and finally centrifuged, and the precipitate after centrifugation is dried to obtain catalyst one; S2: Preparation of Catalyst 2: Dissolve cupric chloride dihydrate in ammonia monohydrate, add hydroxylamine hydrochloride, stir and mix, then add phenylacetylene, seal and stir until no new precipitate is generated, then centrifuge the reaction solution, wash the centrifugal precipitate and dry it to obtain a copper-based coordination polymer; disperse the copper-based coordination polymer in deionized water to obtain a dispersion; add nickel nitrate hexahydrate solution to the dispersion, stir and react, then centrifuge, wash the centrifugal precipitate and dry it to obtain catalyst 2; S3: Catalytic hydrogenation: Under the combined action of alkali, water, catalyst one and catalyst two, resorcinol reacts with hydrogen, and then undergoes acidification and recrystallization to obtain the target product 1,3-cyclohexanedione.

2. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S1, the mass ratio of dodecylamine, ethanol, deionized water and tetraethyl orthosilicate is 10: (80-90): (50-60): (40-45); and / or the temperature of the aging treatment is room temperature and the time is 10-20 hours; and / or the conditions of the calcination treatment are: heating to 500°C at a rate of 5-10°C / min and calcining for 3-5 hours.

3. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S1, the titanium oxide is anatase titanium oxide, and the average particle size of the titanium oxide is 10-20 nm; the mass ratio of the hexagonal mesoporous silica, titanium oxide, and palladium chloride is 1: (1-3): (0.04-0.05).

4. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S1, the stirring treatment time is 1-2h; the concentration of the sodium hydroxide solution is 1 mol / L, the pH of the reaction solution is adjusted to 10-11, the molar ratio of hydrazine hydrate to palladium chloride is (8-10):1; the temperature of the mixed stirring reaction is room temperature, and the time is 2-5h.

5. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S2, the usage ratio of cupric chloride dihydrate, ammonia monohydrate, hydroxylamine hydrochloride and phenylacetylene is 1 mmol: (30-50) ml: (1-2) mmol: 1 ml; and / or the stirring speed of the sealed stirring treatment is 2000-3000 rpm, and the temperature is room temperature.

6. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S2, the mass ratio of the copper-based coordination polymer to nickel nitrate hexahydrate is (3-4):1; and / or the stirring reaction is performed at room temperature for 1-5 hours.

7. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S3, the base is sodium hydroxide, and the mass ratio of resorcinol, sodium hydroxide, water, catalyst one, and catalyst two is 110: (40-50): (300-400): (0.1-0.2): (0.1-0.2).

8. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S3, the reaction temperature is 20-40°C, the reaction pressure is 0.5-1.5 MPa, and the reaction time is 0.5-1h; during acidification, hydrochloric acid is used to adjust the pH of the filtrate to 2-2.5, and the temperature during acidification is 5-10°C and the time is 0.5-1.5h.

9. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 1, characterized in that: In step S3, the recrystallization treatment is to perform a primary crystallization treatment on the acidified filtrate, filter to obtain solid one and filtrate one, mix and stir the filtrate one and the recrystallization solvent, let it stand for treatment, and dry the organic phase to obtain solid two; dissolve solid one and solid two and the recrystallization solvent in the recrystallization solvent again, perform a secondary crystallization treatment, filter, and dry the filter cake to obtain the target product.

10. The method for efficiently preparing 1,3-cyclohexanedione by selective hydrogenation according to claim 9, characterized in that: In step S3, the temperature of the primary crystallization treatment and the secondary crystallization treatment are both 0-5°C, and the time is both 3-5h; and / or the recrystallization solvent is a mixture of dichloromethane and acetonitrile, and the volume ratio of the two is 1:1.

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