A solid acid catalyst for Friedel-Crafts reaction, its preparation method and application

Abstract

This invention proposes a solid acid catalyst for Friedel-Crafts reactions, its preparation method, and its application, belonging to the field of catalyst preparation technology. By weight, the solid acid catalyst comprises 10 parts of molecular sieve, 5-10 parts of ammonium nitrate, and 1 part of concentrated nitric acid; the molecular sieve is HY molecular sieve, HZSM5 molecular sieve, Beta-2 molecular sieve, SAPO-31 molecular sieve, or SBA-15 molecular sieve. The catalyst provided by this invention not only has good catalytic activity and high efficiency, but also produces few byproducts and has a high product yield. Furthermore, when applied to the preparation of pyrrolidone ethanolamine salt, it eliminates the need for catalyst treatment, enabling continuous production of intermediates and avoiding the problem of excessive wastewater generated by the initial process catalyst quenching of aluminum trichloride.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, and particularly relates to a solid acid catalyst for Friedel-Crafts reactions, its preparation method, and its application. Background Technology

[0002] Piroctone olamine salt, structurally named 1-hydroxy-4-methyl-6-(2,4,4,trimethylpentyl)-2-(1H)-pyridone-2-aminoethanol salt, is also known as hydroxypyrrolidone or anti-dandruff agent OCT. Piroctone olamine salt has broad-spectrum bactericidal effects against bacteria and fungi. It is also an anionic surfactant and can be combined with other drugs to enhance their efficacy.

[0003] In related technologies, the synthesis of 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridineethanolamine salt involves first performing a Friedel-Crafts acylation reaction on the raw materials methyl 3,3-dimethacrylate and 3,5,5-trimethylhexanoyl chloride to obtain the intermediate methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid. This intermediate is then subjected to a ring-closing reaction, a hydroxyoxime reaction, and a salt formation reaction to obtain the target product. In the Friedel-Crafts acylation reaction, aluminum trichloride is generally used as a catalyst. Although aluminum trichloride has high catalytic activity and is inexpensive and readily available, it is difficult to recover and reuse, and its treatment generates a large amount of wastewater, making treatment challenging.

[0004] Patent CN112159352A discloses a preparation process for pyrrolidone ethanolamine salt, employing a supported catalyst for the acylation reaction. The supported catalyst specifically includes an active component and a support; the support is silica gel, and the active component includes anhydrous aluminum chloride, anhydrous lanthanum chloride, and anhydrous lithium perchlorate. Although this simplifies the recovery process, the catalytic effect of the catalyst significantly decreases after dozens of reuses, leading to a substantial reduction in reaction yield. Patent CN119462498A uses a solid acid catalyst for the acylation reaction. While the catalyst is easy to recover and has high reusability, the reaction time is too long, resulting in numerous side reactions and a low product yield (the highest product yield is 94.6%). Summary of the Invention

[0005] This invention provides a solid acid catalyst for the Friedel-Crafts reaction, its preparation method, and its application. The catalyst provided by this invention not only has good catalytic activity and high efficiency, but also produces few byproducts and has a high product yield during use. Furthermore, when applied to the process of preparing pyrrolidone ethanolamine salt, it eliminates the need for catalyst treatment, enabling continuous production of intermediates and avoiding the problem of excessive wastewater generated by the initial process catalyst quenching of aluminum trichloride.

[0006] To achieve the above objectives, the present invention provides a solid acid catalyst for Friedel-Crafts reactions, comprising, by weight, 10 parts of molecular sieve, 5-10 parts of ammonium nitrate and 1 part of concentrated nitric acid; wherein the molecular sieve is HY molecular sieve, HZSM5 molecular sieve, Beta-2 molecular sieve, SAPO-31 molecular sieve or SBA-15 molecular sieve.

[0007] Preferably, the solid acid catalyst further includes a promoter metal element; the promoter metal element is one or more selected from cerium, tin, copper, nickel, cobalt and zinc.

[0008] Preferably, the amount of the auxiliary metal element added is 0.1 to 1 wt% of the total amount of the solid acid catalyst.

[0009] The present invention also provides a method for preparing the solid acid catalyst according to any one of the above claims, comprising the following steps:

[0010] 1) Molecular sieve, ammonium nitrate, concentrated nitric acid and water are mixed, stirred, filtered and the solid is collected. The solid is then calcined to obtain the catalyst preproduct.

[0011] 2) The catalyst preproduct is mixed with water, stirred, filtered, and the solid is collected. The solid is then calcined. After calcination, it is mixed with water again, stirred, filtered, and the solid is collected. The solid is then calcined to obtain a solid acid catalyst.

[0012] Preferably, the temperature during stirring in step 1) is 40~120℃ and the time is 5~10h.

[0013] Preferably, after the final roasting in step 2) is completed and the roasted product is obtained, the auxiliary metal element is impregnated onto the roasted product, and roasting is performed after the impregnation is completed.

[0014] Preferably, the roasting temperature in steps 1) and / or 2) is 400~550℃ and the roasting time is 3~10h.

[0015] The present invention also provides the use of the solid acid catalyst described in any one of the above claims in the preparation of methyl 3,7,9,9-tetramethyl-2-decene-5-keto acid, an intermediate in the preparation of pyrrolidone ethanolamine salt;

[0016] The preparation method of the intermediate methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid includes the following steps:

[0017] (1) Methyl 3,3-dimethacrylate and dichloromethane are mixed to obtain component A;

[0018] (2) After mixing component A and 3,5,5-trimethylhexanoyl chloride, the resulting mixture is passed into a tubular reactor filled with a solid acid catalyst to react and obtain intermediate methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid.

[0019] Preferably, in step (2), component A and 3,5,5-trimethylhexanoyl chloride are mixed in a mass ratio of 1:1 to 4, and the temperature during mixing is controlled at -10 to 20°C.

[0020] Preferably, the feed space velocity of the mixture in step (2) into the tubular reactor is 0.1~4.0; the reaction temperature in step (2) is 30~80℃ and the pressure is 0.1~3.5Mpa.

[0021] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0022] The catalyst provided by this invention uses molecular sieves, ammonium nitrate, and concentrated nitric acid as active components, making it a strong acid catalyst. At the same time, the molecular sieve also serves as a carrier, loading other active components onto the molecular sieve to form dual acidic active sites. This results in not only good catalytic activity and high efficiency, but also fewer by-products and a high product yield during use.

[0023] The catalyst provided by this invention, when applied to the preparation of pyrrolidone ethanolamine salt, eliminates the need for catalyst treatment, enabling continuous production of intermediates and avoiding the problem of excessive wastewater generation caused by the initial process catalyst quenching with aluminum trichloride. Simultaneously, the strong acid solid catalyst is packed in a tubular reactor to achieve a continuous flow reaction, and precise temperature control reduces the generation of byproducts and improves product yield. Attached Figure Description

[0024] Figure 1 The image shows a scanning electron microscope (SEM) image of the catalyst prepared in Example 1.

[0025] Figure 2 The purity detection spectrum of intermediate 1 prepared in Example 1;

[0026] Figure 3 Liquid phase spectrum of the product prepared in Example 1;

[0027] Figure 4 The purity detection spectrum of intermediate 1 prepared in Comparative Example 1 is shown.

[0028] Figure 5 The liquid phase spectrum of the product prepared in Comparative Example 1 is shown. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The present invention provides a solid acid catalyst for Friedel-Crafts reactions, wherein the solid acid catalyst comprises 10 parts by weight of molecular sieve, 5-10 parts by weight of ammonium nitrate and 1 part by weight of concentrated nitric acid.

[0031] The solid acid catalyst provided by this invention comprises 10 parts by weight of molecular sieve. In this invention, the molecular sieve is HY molecular sieve, HZSM5 molecular sieve, Beta-2 molecular sieve, SAPO-31 molecular sieve, or SBA-15 molecular sieve. In this invention, the molecular sieve serves both as a support for loading other components and as an active component, providing acidic sites for the catalytic reaction.

[0032] The solid acid catalyst provided by this invention comprises, by weight, 5-10 parts ammonium nitrate and 1 part concentrated nitric acid. Ammonium nitrate primarily removes basic Na from the framework through ammonium ion exchange, releasing NH3 during calcination to form a porous structure, ensuring the catalyst's high acidity, low basicity, and porous structure. Nitric acid plays a role in proton supply and surface hydroxyl protonation, significantly increasing the number of Brønsted acid sites. Ammonium nitrate and concentrated nitric acid form a strongly acidic buffer system, enabling hydrogen protons to bind tightly to the support during preparation, thus enhancing the acidity of the molecular sieve. In this invention, the mass concentration of the concentrated nitric acid is preferably 60-70%.

[0033] The solid acid catalyst provided by this invention preferably further includes a promoter metal element. In this invention, the promoter metal element is preferably one or more of cerium, tin, copper, nickel, cobalt, and zinc. In this invention, the amount of the promoter metal element added is preferably 0.1~1 wt% of the total solid acid catalyst, more preferably 0.4~0.6 wt%. In this invention, the promoter metal element can enhance the strength of Brønsted acid through electronic effects and also provide Lewis acid sites to generate bifunctional acid sites.

[0034] The solid acid catalyst provided by this invention is a strongly acidic catalyst. Based on a molecular sieve catalyst, impregnation with a strong acid enhances the catalyst's acidity and catalytic activity. Impregnation with metal elements forms Brønsted-Lewis acids, bifunctional acidic sites. The two functions are spatially close, enabling them to synergistically complete different chemical steps in the same reaction cycle, further improving the catalyst's activity. This invention prepares the catalyst as a solid acid catalyst, which is then loaded into a tubular reactor. The reaction occurs as the feedstock flows through the catalyst, and the product flows out of the reaction system immediately after the reaction is complete. This reduces the residence time of the product in the system (generally within 15-200 minutes), minimizing side reactions, resulting in high product yield and few byproducts.

[0035] The present invention also provides a method for preparing the solid acid catalyst according to any one of the above claims, comprising the following steps:

[0036] 1) Molecular sieve, ammonium nitrate, concentrated nitric acid and water are mixed, stirred, filtered and the solid is collected. The solid is then calcined to obtain the catalyst preproduct.

[0037] 2) The catalyst preproduct is mixed with water, stirred, filtered, and the solid is collected. The solid is then calcined. After calcination, it is mixed with water again, stirred, filtered, and the solid is collected. The solid is then calcined to obtain a solid acid catalyst.

[0038] This invention involves mixing molecular sieves, ammonium nitrate, concentrated nitric acid, and water, stirring, filtering, collecting the solid, and calcining the solid to obtain a catalyst preproduct. In this invention, the stirring temperature is preferably 40-120°C, and the stirring time is preferably 5-10 hours. The stirring speed is preferably 50-600 r / min. In this invention, the calcination temperature is preferably 400-550°C, and the calcination time is preferably 3-10 hours.

[0039] After obtaining the catalyst preproduct, the present invention mixes the catalyst preproduct with water, stirs, filters, collects the solid, calcines the solid, and after calcination, mixes it with water again, stirs, filters, collects the solid, and calcines the solid to obtain a solid acid catalyst. In the present invention, the stirring temperature is preferably 40~120℃, and the stirring time is preferably 5~10h. The stirring speed is preferably 50~500r / min. In the present invention, the calcination temperature is preferably 400~550℃, and the calcination time is preferably 3~10h.

[0040] In this invention, after obtaining the calcined product, it is preferable to further impregnate the calcined product with an auxiliary metal element, followed by calcination. In this invention, the concentration of the metal element impregnation solution is preferably 0.1~1 wt%. In this invention, the amount of the auxiliary metal element added is preferably 0.1~1 wt% of the total amount of the solid acid catalyst. In this invention, the calcination temperature is preferably 400~550℃, and the calcination time is preferably 3~10 h.

[0041] The method for preparing solid acid catalysts provided by this invention involves three loadings of ammonium nitrate and nitric acid followed by metal ion impregnation. Through multiple loadings, as many alkaline substances in the framework as possible can be removed. During calcination, NH3 is released to form a porous structure, ensuring the catalyst's high acidity and low alkalinity. After loading is completed, metal impregnation is performed, thereby avoiding the re-elution of metal ions on the catalyst by nitric acid.

[0042] The present invention also provides the use of the solid acid catalyst described in any one of the above claims in the preparation of methyl 3,7,9,9-tetramethyl-2-decene-5-keto acid, an intermediate in the preparation of pyrrolidone ethanolamine salt;

[0043] The preparation method of the intermediate methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid includes the following steps:

[0044] (1) Methyl 3,3-dimethacrylate and dichloromethane are mixed to obtain component A;

[0045] (2) After mixing component A and 3,5,5-trimethylhexanoyl chloride, the resulting mixture is passed into a tubular reactor filled with a solid acid catalyst to react and obtain intermediate methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid.

[0046] In this invention, the mass ratio of methyl 3,3-dimethacrylate to dichloromethane in component A is preferably 1:1 to 5. In this invention, component A and 3,5,5-trimethylhexanoyl chloride are preferably mixed at a mass ratio of 1:1 to 4. In this invention, the temperature during mixing of component A and 3,5,5-trimethylhexanoyl chloride is preferably controlled at -10 to 20°C, more preferably 0 to 10°C. In this invention, the feed space velocity of the mixture into the tubular reactor is preferably 0.1 to 4.0. In this invention, the reaction temperature is preferably 30 to 80°C, more preferably 40 to 60°C; the pressure is preferably 0.1 to 3.5 MPa, more preferably 0.5 to 2 MPa.

[0047] In this invention, after obtaining the intermediate methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid, cyclization, hydroxylation, and salt formation reactions are carried out sequentially to obtain pyrrolidone ethanolamine salt. The specific preparation steps are as follows:

[0048] Methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid, intermediate 1, was washed with water, and the organic phase was subjected to a ring-closing reaction at high temperature to obtain the product 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone, intermediate 2.

[0049] The obtained intermediate 2 was mixed with hydroxylamine hydrochloride and sodium carbonate to undergo hydroxylation reaction, yielding 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone, i.e., intermediate 3;

[0050] The prepared 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone was reacted with ethanolamine to form a salt, yielding pyrrolidone ethanolamine salt.

[0051] In this invention, the reactive synthetic route for preparing pyrrolidone ethanolamine salt is shown below:

[0052]

[0053] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0054] Example 1

[0055] Preparation of strong acid solid catalysts:

[0056] 10g of HY molecular sieve, 9g of ammonium nitrate, 1g of 70% concentrated nitric acid solution, and 84g of water were mixed and stirred at 80℃ for 8h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 400℃ for 9h to obtain the catalyst preproduct.

[0057] The catalyst preproduct was mixed with 84g of water, stirred at 80℃ for 8 hours, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 400℃ for 9 hours. After calcination, it was mixed with 84g of water, stirred at 80℃ for 8 hours, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 400℃ for 9 hours to obtain the calcined product.

[0058] 100 mL of 0.5% nickel nitrate was added dropwise to the calcined product obtained above for impregnation. After impregnation, the product was dried at 120°C and then calcined at 400°C for 8 hours to obtain a strongly acidic solid catalyst. The catalyst was then scanned by electron microscopy, as shown in the figure below. Figure 1 As shown.

[0059] Preparation of pyrrolidone ethanolamine salt:

[0060] S1. Methyl 3,3-dimethacrylate and dichloromethane are mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride is used as component B. Components A and B are simultaneously fed into a mixer at a volume ratio of 1:1.2 and mixed at 0°C. The mixture is then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture is controlled at 0.5, and the mixture is purged with nitrogen before feeding. The quartz tube temperature is controlled at 65°C, and the pressure is controlled at 1.5 MPa to produce methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product is obtained after 120 min of the mixture entering the quartz tube). After neutralization, gas chromatography detection is performed (gas chromatography is as follows). Figure 2 As shown in the figure, the product purity is 99.2% and the yield is 98.9%.

[0061] S2. The methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid obtained in S1 was washed with a 10% sodium hydroxide solution at a mass ratio of 1:1. The organic phase was collected by phase separation and heated in a gradient of 40℃-100℃-230℃-250℃ until no light components were produced, to obtain 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone.

[0062] S3. Take 10g of 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone obtained in S2 and add it to 50mL of n-heptane. Add 11g of hydroxylamine hydrochloride and 21g of sodium carbonate and stir well. Heat to 100℃ and reflux for 10h. Then add 100mL of ethyl acetate for extraction. Repeat three times. Combine the organic phases, wash with 50mL of deionized water, and dry with anhydrous sodium sulfate to obtain 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone.

[0063] S4. Add 3g of ethanolamine to the ethyl acetate solution of 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2-pyridone obtained in S3 and mix thoroughly. Heat to 45℃. When crystals precipitate, lower the temperature to 0℃. When the crystals no longer increase in quantity, filter. Wash the obtained solid twice with 50mL of ethyl acetate at 0℃. After drying, obtain pyrrolidone ethanolamine salt. The product was analyzed by liquid chromatography (HPLC chromatogram shown below). Figure 3 As shown in the figure, the purity is 99.5% and the total yield is 75.8%.

[0064] Example 2

[0065] Preparation of strongly acidic solid acid catalysts:

[0066] 10g of HY molecular sieve, 8g of ammonium nitrate, 1g of 70% concentrated nitric acid solution, and 81g of water were mixed and stirred at 50℃ for 10h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 450℃ for 10h to obtain the catalyst preproduct.

[0067] The catalyst preproduct was mixed with 81g of water, stirred at 50°C for 10h, and then filtered to collect the solid. The solid was dried at 80°C and then calcined at 450°C for 10h. After calcination, it was mixed with 81g of water, stirred at 50°C for 10h, and then filtered to collect the solid. The solid was dried at 80°C and then calcined at 450°C for 10h to obtain the calcined product.

[0068] 100 mL of a 0.8% copper nitrate solution was added dropwise to the calcined product obtained above for impregnation treatment. After drying at 100 °C, the product was calcined at 450 °C for 4 h to obtain a strong acid solid catalyst.

[0069] Preparation of pyrrolidone ethanolamine salt:

[0070] S1. Methyl 3,3-dimethacrylate and dichloromethane are mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride is used as component B. Components A and B are simultaneously fed into a mixer at a volume ratio of 1:3.8 and mixed at 5°C. The mixture is then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture is controlled at 1.5, and the mixture is purged with nitrogen before feeding. The temperature of the quartz tube is controlled at 40°C, and the pressure is controlled at 1.8 MPa for the reaction to obtain methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product is obtained after 40 minutes of the mixture entering the quartz tube). After neutralization, gas chromatography analysis shows that the product purity is 99.0% and the yield is 99.2%.

[0071] Following the method of Example 1, steps S2-S4 were performed to obtain pyrrolidone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 99.6% and the yield was 76.2%.

[0072] Example 3

[0073] Preparation of strongly acidic solid acid catalysts:

[0074] 10g of HZSM5 molecular sieve, 5g of ammonium nitrate, 1g of 60% concentrated nitric acid solution, and 84g of water were mixed and stirred at 120℃ for 5h. The mixture was then filtered to collect the solid. The solid was dried at 120℃ and then calcined at 400℃ for 10h to obtain the catalyst preproduct.

[0075] The catalyst preproduct was mixed with 84g of water, stirred at 120℃ for 5h, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 400℃ for 10h. After calcination, it was mixed with 84g of water, stirred at 120℃ for 5h, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 400℃ for 10h to obtain the calcined product.

[0076] 100 mL of 0.5% cerium nitrate solution was added dropwise to the calcined product obtained above for impregnation treatment. After drying at 80°C, it was calcined at 550°C for 3 hours to obtain a strong acid solid catalyst.

[0077] Preparation of pyrrolidone ethanolamine salt:

[0078] S1. Methyl 3,3-dimethacrylate and dichloromethane were mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride was used as component B. Components A and B were simultaneously fed into a mixer at a volume ratio of 1:3 and mixed at 15°C. The mixture was then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture was controlled at 3.7, and the mixture was purged with nitrogen before feeding. The temperature of the quartz tube was controlled at 60°C, and the pressure was controlled at 0.5 MPa to carry out the reaction, yielding methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product was obtained after 16 minutes of the mixture entering the quartz tube). After neutralization, gas chromatography analysis showed that the product purity was 98.5% and the yield was 98.7%.

[0079] Following the method of Example 1, steps S2-S4 were performed to obtain pyrrolidone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 98.8% and the yield was 72.2%.

[0080] Example 4

[0081] Preparation of strongly acidic solid acid catalysts:

[0082] 10g of Beta-2 molecular sieve, 7g of ammonium nitrate, 1g of 70% concentrated nitric acid solution, and 83g of water were mixed and stirred at 80℃ for 8h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 450℃ for 6h to obtain the catalyst preproduct.

[0083] The catalyst preproduct was mixed with 83g of water, stirred at 80℃ for 8 hours, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 450℃ for 6 hours. After calcination, it was mixed with 83g of water, stirred at 80℃ for 8 hours, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 450℃ for 6 hours to obtain the calcined product.

[0084] 100 mL of 0.5% zinc nitrate solution was added dropwise to the calcined product obtained above for impregnation treatment. After drying at 150 °C, it was calcined at 400 °C for 10 h to obtain a strong acid solid catalyst.

[0085] Preparation of pyrrolidone ethanolamine salt:

[0086] S1. Methyl 3,3-dimethacrylate and dichloromethane were mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride was used as component B. Components A and B were simultaneously fed into a mixer at a volume ratio of 1:2.2 and mixed at 12°C. The mixture was then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture was controlled at 2.0, and the mixture was purged with nitrogen before feeding. The temperature of the quartz tube was controlled at 50°C, and the pressure was controlled at 2.0 MPa to carry out the reaction, yielding methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product was obtained after 30 minutes of the mixture entering the quartz tube). After neutralization, gas chromatography analysis showed that the product purity was 99.2% and the yield was 99.1%.

[0087] Following the method of Example 1, steps S2-S4 were performed to obtain pyrrolidone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 99.5% and the yield was 74.2%.

[0088] Example 5

[0089] Preparation of strongly acidic solid acid catalysts:

[0090] 10g of SAPO-31 molecular sieve, 6g of ammonium nitrate, 1g of 70% concentrated nitric acid solution, and 83g of water were mixed and stirred at 80℃ for 10h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 460℃ for 8h to obtain the catalyst preproduct.

[0091] The catalyst preproduct was mixed with 83g of water, stirred at 80℃ for 10h, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 460℃ for 8h. After calcination, it was mixed with 83g of water, stirred at 80℃ for 10h, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 460℃ for 8h to obtain the calcined product.

[0092] 100 mL of a 1% cobalt nitrate solution was added dropwise to the calcined product obtained above for impregnation treatment. After drying at 100 °C, it was calcined at 400 °C for 9 h to obtain a strong acid solid catalyst.

[0093] Preparation of pyrrolidone ethanolamine salt:

[0094] S1. Methyl 3,3-dimethacrylate and dichloromethane were mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride was used as component B. Components A and B were simultaneously fed into a mixer at a volume ratio of 1:1.2 and mixed at -5°C. The mixture was then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture was controlled at 2.8, and the mixture was purged with nitrogen before feeding. The temperature of the quartz tube was controlled at 50°C, and the pressure was controlled at 1.4 MPa to carry out the reaction, yielding methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product was obtained after 21 minutes of the mixture entering the quartz tube). After neutralization, gas chromatography analysis showed that the product purity was 99.4% and the yield was 98.9%.

[0095] Following the method of Example 1, steps S2-S4 were performed to obtain pyrrolidone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 99.1% and the yield was 75.3%.

[0096] Example 6

[0097] Preparation of strongly acidic solid acid catalysts:

[0098] 10g of SBA-15 molecular sieve, 7g of ammonium nitrate, 1g of 70% concentrated nitric acid solution, and 82g of water were mixed and stirred at 80℃ for 8h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 420℃ for 10h to obtain the catalyst preproduct.

[0099] The catalyst preproduct was mixed with 82g of water, stirred at 80℃ for 8 hours, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 420℃ for 10 hours. After calcination, it was mixed with 82g of water, stirred at 80℃ for 8 hours, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 420℃ for 10 hours to obtain the calcined product.

[0100] 100 mL of 0.3% tin nitrate solution was added dropwise to the calcined product obtained above for impregnation treatment. After drying at 110 °C, it was calcined at 400 °C for 7 h to obtain a strong acid solid catalyst.

[0101] Preparation of pyrrolidone ethanolamine salt:

[0102] S1. Methyl 3,3-dimethacrylate and dichloromethane were mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride was used as component B. Components A and B were simultaneously fed into a mixer at a volume ratio of 1:1 and mixed at 12°C. The mixture was then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture was controlled at 0.5, and the mixture was purged with nitrogen before feeding. The temperature of the quartz tube was controlled at 45°C, and the pressure was controlled at 1.9 MPa to carry out the reaction, yielding methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product was obtained after 120 min of the mixture entering the quartz tube). After neutralization, gas chromatography analysis showed that the product purity was 99.6% and the yield was 99.5%.

[0103] Following the method of Example 1, steps S2-S4 were performed to obtain piroctone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 99.3% and the yield was 77.2%.

[0104] Example 7

[0105] Preparation of strong acid solid catalysts:

[0106] 10g of SBA-15 molecular sieve, 7g of ammonium nitrate, 1g of 70% concentrated nitric acid solution, and 82g of water were mixed and stirred at 80℃ for 8h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 420℃ for 10h to obtain the catalyst preproduct.

[0107] The catalyst preproduct was mixed with 82g of water, stirred at 80℃ for 8h, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 420℃ for 10h. After calcination, it was mixed with 82g of water, stirred at 80℃ for 8h, and then filtered to collect the solid. The solid was dried at 80℃ and then calcined at 420℃ for 10h to obtain a strongly acidic solid acid catalyst.

[0108] Preparation of pyrrolidone ethanolamine salt:

[0109] S1. Methyl 3,3-dimethacrylate and dichloromethane were mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride was used as component B. Components A and B were simultaneously fed into a mixer at a volume ratio of 1:1 and mixed at 12°C. The mixture was then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture was controlled at 0.5, and the mixture was purged with nitrogen before feeding. The temperature of the quartz tube was controlled at 45°C, and the pressure was controlled at 1.5 MPa to produce methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product was obtained after 120 min of the mixture entering the quartz tube). After neutralization, gas chromatography analysis showed that the product purity was 99.2% and the yield was 95.2%.

[0110] Following the method of Example 1, steps S2-S4 were performed to obtain piroctone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 99.5% and the yield was 73.5%.

[0111] Comparative Example 1

[0112] Preparation of pyrrolidone ethanolamine salt:

[0113] S1. Mix 7.63 g of methyl 3,3-dimethacrylate and 20.18 g of dichloromethane, then add 10.56 g of aluminum trichloride. Add 4.11 g of 3,5,5-trimethylhexanoyl chloride dropwise, maintaining the temperature at 10 °C. After the addition is complete, raise the temperature to 45 °C and react for 10 h to obtain methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid. Quench the aluminum trichloride with 38 mL of water, separate the phases, wash the organic phase with 19 mL of water, collect the organic phase, and distill the product to remove dichloromethane for gas chromatography analysis (detection chromatogram as shown). Figure 4 As shown in the figure, the product purity is 85.2% and the yield is 90.4%.

[0114] Following the method in Example 1, steps S2-S4 were performed to obtain piroctone ethanol ammonium salt, which was then analyzed by liquid chromatography (detection chromatogram as shown). Figure 5 (As shown) The product purity is 98.6% and the yield is 70.8%.

[0115] Comparative Example 2

[0116] Preparation of strong acid solid catalysts:

[0117] 10g of HY molecular sieve, 1g of 70% concentrated nitric acid solution, and 89g of water were mixed and stirred at 80℃ for 8h. The solid was then collected by filtration. The solid was dried at 80℃ and then calcined at 400℃ for 9h to obtain the catalyst preproduct.

[0118] The catalyst preproduct was mixed with 89 g of water, stirred at 80 °C for 8 h, and then filtered to collect the solid. The solid was dried at 80 °C and then calcined at 400 °C for 9 h. After calcination, it was mixed with 89 g of water, stirred at 80 °C for 8 h, and then filtered to collect the solid. The solid was dried at 80 °C and then calcined at 400 °C for 9 h to obtain the calcined product.

[0119] Step 3: Add 100 mL of 0.5% nickel nitrate to the calcined product for impregnation. After impregnation, dry at 120°C and then calcine at 400°C for 8 hours to obtain a strong acid solid catalyst.

[0120] Preparation of pyrrolidone ethanolamine salt:

[0121] S1. Methyl 3,3-dimethacrylate and dichloromethane are mixed at a mass ratio of 1:1 as component A. 3,5,5-trimethylhexanoyl chloride is used as component B. Components A and B are simultaneously fed into a mixer at a volume ratio of 1:1.2 and mixed at 0°C. The mixture is then passed through a quartz tube (10 mm in diameter and 1 m in length) filled with the aforementioned strong acid solid catalyst. The feed space velocity of the mixture is controlled at 0.5, and the mixture is purged with nitrogen before feeding. The temperature of the quartz tube is controlled at 65°C, and the pressure is controlled at 1.5 MPa for the reaction to obtain methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid (the reaction product is obtained after 120 min of the mixture entering the quartz tube). After neutralization, gas chromatography analysis shows that the product purity is 94.8% and the yield is 92.8%.

[0122] Following the method of Example 1, steps S2-S4 were performed to obtain piroctone ethanol ammonium salt. Liquid chromatography analysis showed that the product purity was 99.0% and the yield was 71.5%.

[0123] Performance testing

[0124] After using the catalysts from Examples 1 to 7 continuously for 30 days, the purity and yield of intermediate 1 (methyl 3,7,9,9-tetramethyl-2-decen-5-keto acid ester) were determined. The specific results are shown in Table 1.

[0125] Table 1

[0126]

[0127] As can be seen from Table 1, the catalyst prepared in this application has excellent catalytic selectivity and stability. After 30 days of continuous catalysis, the activity did not decrease, indicating that the solid acid catalyst has a long service life.

[0128] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Use of a solid acid catalyst for the preparation of the intermediate 3,7,9,9-tetramethyl-2-decenen-5-one acid methyl ester for the preparation of piroctone olamine, characterized in that, The preparation method of the intermediate 3,7,9,9-tetramethyl-2-deceno-5-ketonic acid methyl ester comprises the following steps: (1) mixing methyl 3,3-dimethyl acrylate and dichloromethane to obtain component A; (2) mixing component A and 3,5,5-trimethyl hexanoyl chloride, and then feeding the obtained mixture into a tubular reactor filled with a solid acid catalyst to perform reaction, so as to obtain the intermediate 3,7,9,9-tetramethyl-2-deceno-5-ketonic acid methyl ester; The solid acid catalyst comprises 10 parts of molecular sieve, 5-10 parts of ammonium nitrate and 1 part of concentrated nitric acid by weight; the molecular sieve is HY molecular sieve, HZSM5 molecular sieve, Beta-2 molecular sieve, SAPO-31 molecular sieve or SBA-15 molecular sieve; The solid acid catalyst is prepared by the following steps: 1) mixing the molecular sieve, ammonium nitrate, concentrated nitric acid and water, stirring, filtering, collecting the solid, and calcining the solid to obtain a catalyst precursor; 2) mixing the catalyst precursor and water, stirring, filtering, collecting the solid, and calcining the solid to obtain the solid acid catalyst; The solid acid catalyst further comprises an auxiliary metal element; the auxiliary metal element is one or more of cerium, tin, copper, nickel, cobalt and zinc; After the calcination of the last time in step 2) is completed, the auxiliary metal element is further impregnated on the calcination product, and then calcination is performed.

2. Use according to claim 1, characterized in that, The addition amount of the auxiliary metal element is 0.1-1wt% of the total amount of the solid acid catalyst.

3. Use according to claim 1, characterized in that, The temperature during stirring in step 1) is 40-80℃, and the time is 5-10h.

4. Use according to claim 1, characterized in that, The temperature during calcination in steps 1) and / or 2) is independently 400-550℃, and the time is independently 3-10h.

5. The use according to claim 1, characterized in that, In step (2), component A and 3,5,5-trimethyl hexanoyl chloride are mixed at a mass ratio of 1:1-4, and the temperature during mixing is controlled at -10-20℃.

6. The use according to claim 1, characterized in that, The temperature during reaction in step (2) is 30-80℃, and the pressure is 0.1-3.5Mpa.

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