Solid catalyst for synthesizing triazole by methyl ethyl ketazine method

Abstract

The invention discloses a solid catalyst for synthesizing triazole by a methyl ethyl ketazine method. The preparation method of the solid catalyst comprises the following steps: (1) enabling mesoporous carbon to react with an oxidizing agent, and introducing carboxyl on the surface of the mesoporous carbon; (2) reacting the carboxylated mesoporous carbon with alkyl diamine, and grafting an alkyl amino chain; (3) reacting the product obtained in the step (2) with an acylating agent, and introducing a fatty acid amide group to the terminal amino group; and (4) reacting the product obtained in the step (3) with alkylsilane to form a hydrophobic layer. Fatty acid amide is adopted as an active group and has nucleophilicity and catalytic activity; a flexible space is provided through alkyl chain connection, and steric hindrance is reduced; hydrophobic modification is adopted, so that good mass transfer efficiency is kept while an active center is protected. The yield of the catalyst in methyl ethyl ketazine synthesis can reach 90-92%, and the catalyst can be recycled 6-8 times, and has the advantages of high activity, good stability, easy recovery and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fine chemical industry and catalysis technology, and particularly relates to a solid catalyst for synthesizing triazole by butanone hydrazine method. BACKGROUND

[0002] 1,2,4-Triazole is an important nitrogen-containing heterocyclic compound, which has wide applications in the fields of medicine, pesticide and functional materials. In the field of medicine, 1,2,4-triazole and its derivatives are the core structural units of various antifungal drugs (such as fluconazole, itraconazole) and antiviral drugs (such as ribavirin), and more than 15 drugs containing this structure are currently sold on the market. In the field of pesticides, 1,2,4-triazole derivatives such as triadimefon and paclobutrazol have become important fungicides and plant growth regulators. With the continuous expansion of downstream applications, the global demand for 1,2,4-triazole is increasing year by year, and it is of great significance to develop efficient, green and economical synthesis technology.

[0003] At present, the industrial synthesis methods of 1,2,4-triazole mainly include hydrazine-formamide method, thiosemicarbazide oxidation method and butanone hydrazine method. The hydrazine-formamide method is the most classic method, which is prepared by the reaction of hydrazine and formamide at 140-210°C. The yield of this method can reach 92-98%, but this method uses dangerous hydrazine as raw material, has high safety risk and high cost, the storage and transportation of hydrazine are strictly regulated, and does not conform to the concept of green chemistry. Although the thiosemicarbazide oxidation method avoids the use of hydrazine, it has many process steps, needs to go through acylation, cyclization, oxidation desulfurization and other steps, the separation and purification of intermediate products are complicated, the total yield is low, and the economic benefit is not high.

[0004] In actual industrial production, there are differences in the stability of raw material supply and cost fluctuation of different synthesis routes. As a regulated chemical, the supply of hydrazine is strictly regulated, and there may be a situation of temporary supply shortage or large price fluctuation in special period (such as equipment maintenance of supplier, transportation regulation, etc.). Therefore, developing multiple alternative synthesis process routes and establishing a flexible production system are of great strategic significance for ensuring the stable supply of triazole and reducing the risk of raw material price fluctuation.

[0005] The butanone azine method is a green synthesis route developed in recent years. The method uses cheap and readily available butanone as raw material to produce 1,2,4-triazole through two-step reaction. The first step is the reaction of butanone with ammonia and hydrogen peroxide to produce butanone azine. The second step is the cyclization of butanone azine with formamide at high temperature of 165-190°C to produce 1,2,4-triazole, and the by-product butanone can be recycled. In the preparation step of butanone azine, organic amide (such as formamide, acetamide) is used as catalyst, which can make the yield reach 75-85%. However, the homogeneous catalyst is mixed with the product, and an excess amount is needed to compensate for the loss of separation. Although formamide can be recovered from the aqueous phase by distillation, in the integrated production process, additional distillation equipment and energy consumption are required.

[0006] CN119930465A discloses a synthesis method of butanone azine. The patent uses cyanogen covalent organic framework material (COF) as a solid catalyst, and uses the cyanogen in the COF skeleton to hydrolyze in situ to amide to catalyze the reaction, and the yield of butanone azine can reach 85-89%. However, the COF material has problems such as complex preparation process, high cost, and poor mechanical strength, and the patent does not provide detailed data on the recycling of the catalyst, and its long-term stability and industrial feasibility need to be verified.

[0007] Therefore, it is of great significance to develop a solid catalyst with high activity, easy separation and recycling for simplifying the process, reducing the cost and improving the safety. SUMMARY

[0008] Based on the problems in the background art, the present application provides a solid catalyst for synthesizing triazole by butanone azine method, which improves the yield and efficiency of butanone azine synthesis and reduces the production cost. It is of great significance for the technical progress and industrial application of 1,2,4-triazole prepared by butanone azine method.

[0009] The present application is implemented by the following technical solutions: The present application discloses a preparation method of a solid catalyst for synthesizing triazole by butanone azine method, comprising the following steps: (1) Carboxylation of mesoporous carbon: reacting mesoporous carbon with an oxidizing agent to introduce carboxyl groups on the surface of mesoporous carbon; (2) Grafting of alkyl diamine: reacting the carboxylated mesoporous carbon obtained in step (1) with alkyl diamine to graft alkyl amino groups on the surface of mesoporous carbon; (3) Terminal acylation: reacting the product obtained in step (2) with an acylating agent to introduce fatty amide groups on the terminal amino groups; (4) Hydrophobic modification: reacting the product obtained in step (3) with alkyl silane to form a hydrophobic layer on the surface.

[0010] Preferably, the mesoporous carbon in step (1) is selected from one of ordered mesoporous carbon, disordered mesoporous carbon, commercial mesoporous carbon, and the specific surface area of the mesoporous carbon is 400-1500 m 2 / g, and the pore size is 3-12 nm.

[0011] Preferably, the oxidizing agent in step (1) is selected from one or more of concentrated nitric acid, concentrated sulfuric acid, hydrogen peroxide, and potassium permanganate; and the reaction conditions are a temperature of 60-100℃ and a time of 4-12 hours.

[0012] Preferably, step (2) further comprises a carboxyl activation step before the carboxylated mesoporous carbon is reacted with the alkyl diamine, and the carboxyl activation converts the carboxyl groups of the carboxylated mesoporous carbon into active intermediates using an activating agent selected from one or more of EDC·HCl, DCC, and CDI, and an auxiliary activating agent selected from one or more of NHS and HOBt.

[0013] Preferably, the alkyl diamine in step (2) is selected from one or more of 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and 1,8-octanediamine; and the amount of the alkyl diamine is 10-20 times the molar amount of the carboxyl groups in the carboxylated mesoporous carbon, so as to ensure single-end grafting; and the reaction conditions are a temperature of 30-60℃ and a time of 12-24 hours.

[0014] Preferably, the acylating agent in step (3) is selected from one or more of formic acid / coupling agent, acetic anhydride, propionic anhydride, butyric anhydride, and isobutyric anhydride; when formic acid / coupling agent is used, the coupling agent is selected from one of EDC·HCl and DCC; when an anhydride is used, a base needs to be added as an acid-binding agent, and the base is selected from one or more of triethylamine, pyridine, and N-methylmorpholine; and the reaction conditions are a temperature of 0-50℃ and a time of 4-12 hours.

[0015] Preferably, the amount of the hydrophobically modified alkyl silane in step (4) is 5-12 wt% of the mass of the product of step (3); the alkyl silane is selected from one or more of C6-C18 alkyl trialkoxysilane and C6-C18 alkyl trichlorosilane; and the reaction conditions are a temperature of 50-80℃ and a time of 2-6 hours.

[0016] The application also discloses a solid catalyst prepared by the above method, which comprises a mesoporous carbon carrier, a fatty amide group connected by an alkyl chain and loaded on the mesoporous carbon carrier, and a hydrophobically modified layer on the surface of the mesoporous carbon carrier.

[0017] Preferably, the fatty amide group is selected from one or more of formamide, acetamide, propionamide, butyramide, and isobutyramide; and the number of carbon atoms in the alkyl chain is 3-8.

[0018] The application finally discloses application of the solid catalyst in synthesis of triazole from butanone azine, which comprises the following steps: adding the solid catalyst, inorganic base and hydrogen peroxide into a reaction container; adding butanone and ammonia water, and reacting at 30-70℃ for 2-10 hours; filtering and separating the catalyst, and separating butanone azine from the filtrate; and butanone azine continues to react with formamide to generate triazole.

[0019] The application has the following beneficial effects: 1. The application uses fatty amide as an active group, which shows high catalytic activity in the synthesis reaction of butanone azine. Through flexible alkyl chain (C3-C8) connection, the active site is far away from the carrier surface, the steric hindrance is greatly reduced, and the contact efficiency of reactants and active sites is significantly improved. In the hydrophobic modification step, the amount of alkyl silane used is only 30-50% of that of the traditional method, the coverage of the formed hydrophobic layer is about 70%, and 30% of the "hydrophilic channel" is reserved, which protects the active center while ensuring that the reactants can fully enter the pore. The hydrophobic layer effectively slows down the hydrolysis rate of the fatty amide group under alkaline aqueous conditions, so that the catalyst can be recycled for 6-8 times, and the butanone azine yield can still be maintained at more than 84-86% after 6 times of recycling (retention rate ≥93%), which is better than that of fatty amide catalyst without hydrophobic protection (3-5 times of recycling).

[0020] 2. The preparation method of the application has clear steps and mild conditions, does not require complex solvothermal synthesis, strict water-free and oxygen-free operation or high-temperature and high-pressure equipment, and all the raw materials used are commercial products with moderate prices and easy availability. The preparation cost is much lower than that of COF catalysts (>2000 yuan / kg), and it has good industrialization prospects. The mesoporous carbon carrier has excellent mechanical strength and chemical stability, and can be formed into particles or microspheres (particle size 0.2-2 mm) which are not easy to break during stirring, filtration and other operations. High-efficiency recovery of the catalyst can be realized through simple filtration. The solid catalyst is easy to accurately weigh and automatically feed, avoiding the metering error and volatilization loss of liquid catalysts, improving the batch stability of production, and being suitable for continuous and automatic production. DETAILED DESCRIPTION

[0021] The technical solutions of the application will be further described below in combination with specific embodiments, but the protection scope of the application is not limited to the following embodiments.

[0022] Example 1: Preparation of hexanediamine-acetamide functionalized mesoporous carbon catalyst (FAM-MC-1).

[0023] Step 1. Carboxylation of mesoporous carbon: 50.0 g of commercially available mesoporous carbon (specific surface area 850 m 2 / g, average pore size 10 nm, pore volume 1.2 cm 3The carboxylated mesoporous carbon (MC-COOH) was added to a 1000 mL three-necked flask, followed by 500 mL of concentrated nitric acid (68% by mass, Sinopharm Chemical Reagent Co., Ltd.). A reflux condenser was then installed. The mixture was refluxed in an oil bath at 80 °C for 8 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered through a Buchner funnel, and washed with deionized water until the pH of the filtrate reached 6-7. The resulting black solid was dried in a vacuum drying oven at 80 °C for 12 hours to obtain 47.2 g of carboxylated mesoporous carbon (MC-COOH).

[0024] Step 2. Carboxyl activation: 20.0 g of MC-COOH (containing 56 mmol of carboxyl groups) was dispersed in 300 mL of anhydrous DMF and sonicated for 10 minutes to ensure uniform dispersion. Then, 16.1 g of EDC·HCl (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) and 9.7 g of NHS (N-hydroxysuccinimide) were added sequentially, and the mixture was magnetically stirred at room temperature for 4 hours. After the reaction, the mixture was filtered through a Buchner funnel and washed sequentially with anhydrous DMF and anhydrous ethanol to remove excess EDC, NHS, and byproducts. The resulting solid was dried in a vacuum oven at 60 °C for 6 hours to obtain 19.8 g of the activated product (MC-NHS).

[0025] Step 3. Grafting hexamethylenediamine: 19.8 g of MC-NHS was dispersed in 350 mL of anhydrous DMF, and 97.5 g of 1,6-hexamethylenediamine was added. The reaction was carried out under magnetic stirring in an oil bath at 40 °C for 18 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered through a Buchner funnel, and washed successively with DMF, ethanol, and deionized water. The resulting black solid was dried in a vacuum drying oven at 80 °C for 12 hours to obtain 18.5 g of amino-functionalized mesoporous carbon (MC-C6-NH2).

[0026] Step 4. Terminal acetylation: 18.5 g of MC-C6-NH2 was dispersed in 250 mL of anhydrous dichloromethane and cooled to 0 °C in an ice-water bath. Under vigorous stirring, 4.7 g of triethylamine and 4.7 g of acetic anhydride were slowly added dropwise over approximately 30 minutes, maintaining a temperature of 0-5 °C during the addition. After the addition was complete, the ice-water bath was removed, the temperature was raised to room temperature, and the reaction was continued with stirring for 6 hours. After the reaction was complete, the mixture was filtered through a Buchner funnel and washed successively with dichloromethane, methanol, and deionized water. The resulting solid was dried in a vacuum drying oven at 80 °C for 12 hours to obtain 17.8 g of acetamide-functionalized mesoporous carbon (MC-C6-NHAc).

[0027] Step 5. Hydrophobic Modification: 17.8 g of MC-C6-NHAc was dispersed in 220 mL of anhydrous toluene and sonicated for 5 minutes to ensure uniform dispersion. 1.42 g of n-octyltriethoxysilane (8.0 wt% of the mass of MC-C6-NHAc) was added. The reaction was refluxed at 60 °C in an oil bath for 3.5 hours. The reaction temperature and time were lower than traditional hydrophobic modification (typically 80 °C, 6 hours) to form a low-density, incomplete hydrophobic layer. After the reaction, the mixture was cooled to room temperature, filtered through a Buchner funnel, and washed successively with toluene and ethanol. The resulting solid was dried in a vacuum oven at 80 °C for 12 hours to obtain 17.2 g of the final catalyst FAM-MC-1 (fatty amide functionalized mesoporous carbon), a light gray-black powder.

[0028] Example 2: Catalysts with different alkyl diamine chain lengths.

[0029] Following the method of Example 1, in step 3, 1,4-butanediamine and 1,8-octanediamine were used instead of 1,6-hexanediamine, respectively, while other conditions and amounts (molar ratio) remained the same. The catalysts FAM-MC-2 (butanediamine-acetamide functionalized) and FAM-MC-3 (octanediamine-acetamide functionalized) were finally obtained.

[0030] Example 3: Catalysts with different acylation types.

[0031] MC-C6-NH2 was prepared according to steps 1-3 of Example 1. In step 4, terminal acylation was performed using the following methods: Method A (Formylation): 18.5 g of MC-C6-NH2 was dispersed in 300 mL of anhydrous DMF, and 1.53 g of formic acid, 6.3 g of EDC·HCl, and 4.5 g of HOBt (1-hydroxybenzotriazole) were added sequentially. The mixture was stirred at room temperature for 12 hours. The post-treatment was the same as step 4 in Example 1, yielding 17.6 g of formamide-functionalized mesoporous carbon (MC-C6-NHCHO).

[0032] Method B (propionylation): 18.5g of MC-C6-NH2 was dispersed in 250mL of anhydrous dichloromethane. Triethylamine 3.9g and propionic anhydride 3.9g were added sequentially at 0℃. The subsequent operations were the same as step 4 of Example 1, to obtain 17.5g of propionamide-functionalized mesoporous carbon (MC-C6-NHPr).

[0033] Hydrophobic modification was carried out according to step 5 of Example 1, and finally catalysts FAM-MC-4 (formamide type) and FAM-MC-5 (propionamide type) were obtained.

[0034] Example 4: Catalysts with different loadings.

[0035] Step 1: Carboxylation of mesoporous carbon: 50.0 g of commercially available mesoporous carbon was added to a 1000 mL three-necked flask, and 500 mL of concentrated nitric acid was added. The mixture was refluxed at 90 °C in an oil bath for 12 hours (4 hours longer than in Example 1). The post-treatment method was the same as in Step 1 of Example 1, yielding 47.5 g of MC-COOH.

[0036] Steps 2-5: Follow steps 2-5 of Example 1, but increase the amounts of EDC·HCl, NHS, hexamethylenediamine, and acetic anhydride according to the carboxyl content to obtain catalyst FAM-MC-6.

[0037] Example 5: Catalysts with different amounts of hydrophobic agent.

[0038] MC-C6-NHAc was prepared according to steps 1-4 of Example 1. In step 5, hydrophobic modification was performed using 0.89 g (5 wt% of the mass of MC-C6-NHAc, low amount) and 2.13 g (12 wt%, high amount) of n-octyltriethoxysilane, respectively, under the same conditions, to obtain catalysts FAM-MC-7 (very low density hydrophobic layer) and FAM-MC-8 (medium density hydrophobic layer).

[0039] Comparative Example 1: Fatty amide catalyst without hydrophobic layer.

[0040] MC-C6-NHAc was prepared according to steps 1-4 of Example 1. Step 5 was skipped (no hydrophobic modification was performed), and it was used directly as a catalyst, denoted as FAM-MC-9 (fatty amide + no hydrophobic layer).

[0041] Comparative Example 2: Fatty amide catalysts with traditional high-density hydrophobic layers.

[0042] MC-C6-NHAc was prepared according to steps 1-4 of Example 1. In step 5, 4.45 g of n-octyltriethoxysilane (25 wt% of the mass of MC-C6-NHAc, conventionally high dosage) was used and refluxed at 80 °C for 6 hours to obtain catalyst FAM-MC-10 (fatty amide + high-density hydrophobic layer).

[0043] Application Example 1: FAM-MC-1 catalyst was used for the synthesis of 1,2,4-triazole via the butanone azotization process.

[0044] Step 1. Synthesis of Butanone Azo: In a 100 mL three-necked flask, add 1.0 g of FAM-MC-1 catalyst, 1.2 g of K₂CO₃, and 0.5 mL of DMSO, followed by 14 g of 30% H₂O₂ aqueous solution. Stir at room temperature for 2 hours. Then, add 40.0 g of butanone and 20 g of 25% ammonia solution sequentially. Heat to 50°C and continue stirring for 5 hours. After the reaction is complete, cool to room temperature, filter using a sintered glass funnel to recover the solid catalyst, and allow the filtrate to separate into layers. Take the upper oil phase as the crude butanone azo product and analyze it using gas chromatography.

[0045] Results: The yield of methyl ethyl ketone (MEK) was 91.5%, and the gas chromatographic purity was 98.1% (the main impurity was 1.2% residual MEK, and other impurities were 0.7%). In this application example, excess MEK was used as a solvent to improve reactant concentration and mass transfer efficiency. Approximately 50% of the MEK actually participated in the reaction, and the remaining MEK was recovered and recycled through distillation.

[0046] Step 2.1, Synthesis of 1,2,4-triazole: 100.0 g of formamide was added to a 250 mL three-necked flask equipped with a distillation column, and the mixture was heated to 165-170°C in an oil bath. At this temperature, 32.8 g of crude butanone azide obtained in Step 1 was slowly added dropwise to the formamide using a constant-pressure dropping funnel over approximately 2 hours. During the addition, the reaction temperature was maintained at 165-170°C, while simultaneously distilling off a mixture of butanone and water. After the addition was complete, the reaction was maintained at this temperature for 4 hours until the amount of butanone distilled off no longer increased. The mixture was cooled to 80°C, diluted with 50 mL of hot water, and further cooled to room temperature, resulting in the precipitation of white crystals. The crystals were filtered, and the formamide was recovered by vacuum distillation of the filtrate. The white crystals were washed with a small amount of cold water and dried at 60°C to obtain white crystalline 1,2,4-triazole with a purity (HPLC method) of 99.3%.

[0047] Application Examples 2-7: Performance Comparison of Different Catalysts

[0048] Following the method in step 1 of Application Example 1, catalysts FAM-MC-2 to FAM-MC-10 prepared in Examples 2-5 and Comparative Examples 1-2 were used for the synthesis of butanone azohydride (step 1 was performed only, without subsequent triazole synthesis), with identical reaction conditions and amounts. The results are summarized in Table 1.

[0049] Table 1. Performance of different catalysts in the first-use synthesis of butanone-azohydride As shown in Table 1, compared to FAM-MC-9 (without hydrophobic layer, 93.2%) and FAM-MC-1 (low-density hydrophobic layer, 91.5%), the low-density hydrophobic layer slightly reduced the initial yield by 1.7 percentage points. This is an acceptable sacrifice, as the main function of the hydrophobic layer is to improve cycling stability (see Application Example 8). Compared to FAM-MC-1 (low density, 91.5%) and FAM-MC-10 (high density, 88.3%), the low-density hydrophobic layer improved the yield by 3.2 percentage points, demonstrating that the low-density hydrophobic design effectively maintains mass transfer efficiency while protecting the active centers.

[0050] Application Example 8: Catalyst Recycling Test.

[0051] The synthesis of methyl ethyl ketone (MEK) azide was carried out using the FAM-MC-1 catalyst, following step 1 of Application Example 1. After the reaction, the catalyst was recovered by filtration, washed with ethanol (20 mL × 2 times), dried at 80°C for 2 hours, and then directly reused without any regeneration. Eight consecutive cycles were performed. The crude MEK azide obtained in each cycle was cyclized to prepare triazole according to step 2 of Application Example 1 to verify the product quality. The catalyst recovery rate was >96% in each cycle, indicating excellent mechanical strength of the mesoporous carbon support and minimal loss during filtration. The results are shown in Table 2.

[0052] Table 2. Cyclic Use Test Results of FAM-MC-1 As shown in Table 2, after 6 cycles, the yield of methyl ethyl ketone (MEK) remained at 85.8%, representing a 93.8% retention rate relative to the initial yield (91.5%), which is superior to the catalyst without a hydrophobic layer (see Application Example 9). After 8 cycles, the yield decreased to 82.7%. The purity of MEK remained above 96.8% throughout the entire cycle, and the purity of triazole remained above 98.9%, indicating that catalyst recycling does not introduce impurities that affect subsequent reactions, and the product quality is reliable.

[0053] Application Example 9: Recycling of catalysts without hydrophobic layers.

[0054] Using the catalyst FAM-MC-9 (fatty amide + no hydrophobic layer) from Comparative Example 2, a recycling test was conducted according to the method in Application Example 7. The results are shown in Table 3.

[0055] Table 3. Cyclic Test Results of FAM-MC-9 (without hydrophobic layer) As shown in Table 3, without a hydrophobic layer, the pores are completely open, mass transfer is unimpeded, and the utilization rate of active sites is the highest, resulting in the highest initial yield. The yield decreases by approximately 4 percentage points after each cycle (compared to approximately 1 percentage point decrease for FAM-MC-1 each cycle). By the third cycle, the yield has dropped to 85.2%, comparable to the sixth cycle of FAM-MC-1; after the fifth cycle, the yield drops to 76.5%, making it unsuitable for further use. Although the catalyst without a hydrophobic layer exhibits the highest initial activity, its poor cycle stability and lower long-term economics compared to catalysts with low-density hydrophobic layers are due to the rapid hydrolysis of aliphatic amide groups under alkaline aqueous conditions. This demonstrates the necessity of hydrophobic protection.

[0056] Finally, it should be noted that the above embodiments are merely illustrative of several implementations of the present invention and are not intended to limit the scope of the invention. For those skilled in the art, any modifications, equivalent substitutions, or improvements made without departing from the concept of the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing a solid catalyst for the synthesis of triazole via the butanone-azonium process, characterized in that, Includes the following steps: (1) Carboxylation of mesoporous carbon: Mesoporous carbon is reacted with an oxidant to introduce carboxyl groups on the surface of mesoporous carbon; (2) Grafting alkyl diamine: The carboxylated mesoporous carbon obtained in step (1) is reacted with alkyl diamine to graft alkyl amino groups onto the surface of the mesoporous carbon; (3) Terminal acylation: The product obtained in step (2) is reacted with an acylation agent to introduce a fatty amide group onto the terminal amino group; (4) Hydrophobic modification: The product obtained in step (3) is reacted with alkylsilane to form a hydrophobic layer on the surface.

2. The preparation method according to claim 1, characterized in that, The mesoporous carbon mentioned in step (1) is selected from ordered mesoporous carbon, disordered mesoporous carbon, and commercially available mesoporous carbon, and the specific surface area of ​​the mesoporous carbon is 400-1500 m². 2 / g, with a pore size of 3-12nm.

3. The preparation method according to claim 1, characterized in that, The oxidant in step (1) is selected from one or more of concentrated nitric acid, concentrated sulfuric acid, hydrogen peroxide, and potassium permanganate; the reaction conditions are a temperature of 60-100℃ and a time of 4-12 hours.

4. The preparation method according to claim 1, characterized in that, In step (2), before the carboxylated mesoporous carbon reacts with the alkyl diamine, there is a carboxyl activation step. The carboxyl activation uses an activator to convert the carboxyl group of the carboxylated mesoporous carbon into an active intermediate. The activator is selected from one or more of EDC·HCl, DCC, and CDI, and the auxiliary activator is selected from one or more of NHS and HOBt.

5. The preparation method according to claim 1, characterized in that, The alkyl diamine mentioned in step (2) is selected from one or more of 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and 1,8-octanediamine; the amount of alkyl diamine used is 10-20 times the molar amount of carboxyl groups in the carboxylated mesoporous carbon to ensure single-end grafting; the reaction conditions are a temperature of 30-60℃ and a time of 12-24 hours.

6. The preparation method according to claim 1, characterized in that, The acylating agent in step (3) is selected from one or more of formic acid / coupling agent, acetic anhydride, propionic anhydride, butyric anhydride, and isobutyric anhydride; when formic acid / coupling agent is used, the coupling agent is selected from one of EDC·HCl and DCC; when acid anhydride is used, a base needs to be added as an acid-binding agent, and the base is selected from one or more of triethylamine, pyridine, and N-methylmorpholine; the reaction conditions are a temperature of 0-50℃ and a time of 4-12 hours.

7. The preparation method according to claim 1, characterized in that, The amount of hydrophobically modified alkylsilane used in step (4) is 5-12 wt% of the product mass in step (3); the alkylsilane is selected from one or more of C6-C18 alkyltrialkoxysilane and C6-C18 alkyltrichlorosilane; the reaction conditions are a temperature of 50-80℃ and a time of 2-6 hours.

8. A solid catalyst prepared by the method according to any one of claims 1-7, characterized in that, It includes a mesoporous carbon support, fatty amide groups linked by alkyl chains and loaded on the mesoporous carbon support, and a hydrophobic modified layer on the surface of the mesoporous carbon support.

9. The solid catalyst according to claim 8, characterized in that, The fatty amide group is selected from one or more of formamide, acetamide, propionamide, butyramide, and isobutyramide; the alkyl chain has 3-8 carbon atoms.

10. The application of the solid catalyst according to claim 8 or 9 in the synthesis of triazole via the butanone-azonium process, characterized in that, The process includes the following steps: adding the solid catalyst, inorganic base, and hydrogen peroxide to a reaction vessel; adding butanone and ammonia; and reacting at 30-70°C for 2-10 hours. The catalyst was separated by filtration, and methyl ethyl ketone (MEK) was obtained from the filtrate. MEK then reacted with formamide to produce triazole.

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