Method for preparing 1H-imidazole-4-formic acid based on supported copper-based catalyst

Abstract

The invention relates to the technical field of organic synthesis, and particularly discloses a method for preparing 1H-imidazole-4-formic acid based on a supported copper-based catalyst, which comprises the following steps: preparing the supported copper-based catalyst; the preparation method comprises the following steps: adding imidazole-4, 5-dicarboxylic acid and a solvent into a reaction bottle, stirring and heating, then adding the catalyst, carrying out a primary stirring reaction, then slowly heating, carrying out a secondary stirring reaction, tracking the completion of the reaction of the raw materials in the reaction process, and cooling to room temperature; and adding deionized water into the reaction solution, stirring and washing, cooling to room temperature, filtering the reaction solution, precipitating and washing, and drying to obtain the target product 1H-imidazole-4-formic acid. According to the invention, imidazole-4, 5-dicarboxylic acid is taken as a starting material, decarboxylation reaction is carried out under the self-made catalyst, a target product is synthesized, the reaction condition is mild, the process is simple and easy to control, side reactions are few, the safety is high, and the purity and yield of the product are greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst. Background Art

[0002] 1H-imidazole-4-carboxylic acid, also known as imidazole-4-carboxylic acid, is an organic compound with the chemical formula C4H4N2O2. It is soluble in acidic aqueous solution and appears as a transparent, colorless liquid. 1H-imidazole-4-carboxylic acid is not only an important intermediate for the synthesis of imidazole drugs with a wide range of pharmacological activities, but also has significant biological activity itself. It can be used to synthesize imidazole-functionalized polypropyleneimine dendritic structure compounds, and thus has important chemical application value.

[0003] Patent application number 201210037792.0 discloses the following technical scheme: a method for preparing 1H-imidazole-4-carboxylic acid, using ethyl acetylglycine as a raw material, and obtaining ethyl 2-mercapto-4-imidazolecarboxylate through cyclization with potassium thiocyanate; using a catalyst to catalyze oxidation to remove the mercapto group, obtaining ethyl imidazole-4-carboxylate without mercapto group, and then hydrolyzing to obtain the target compound 1H-imidazole-4-carboxylic acid. In the above scheme, ethyl 2-mercapto-4-imidazolecarboxylate contains sulfur, and catalyst poisoning is easily caused when using catalytic hydrogenation reduction to remove the mercapto group. A large amount of catalyst is required to complete the reaction, which increases the reaction cost.

[0004] The patent application number is 201610108975.5. The following technical scheme is disclosed: a method for preparing 1H-imidazole-4-carboxylic acid, the steps of which are as follows: dissolving bismuth nitrate and sodium tungstate in deionized water, homogenizing, transferring to a hydrothermal reaction tank, sealing and placing in an oven, reacting, cooling to room temperature, washing, drying, and grinding to obtain bismuth tungstate powder; adding CTAB to distilled water, stirring, adding tetraethyl orthosilicate and bismuth tungstate powder, continuing to stir, aging, filtering, washing, drying, and roasting. The composite catalyst is obtained; 2-mercapto-1H-imidazole-4-carboxylic acid ethyl ester and ethanol solution are added to a three-necked flask, the composite catalyst is added, stirred, cooled, a hydrogen peroxide solution is added dropwise, heated, rotary evaporated, stirred, allowed to stand, and filtered to obtain 1H-imidazole-4-carboxylic acid ethyl ester; 1H-imidazole-4-carboxylic acid ethyl ester is dissolved in distilled water, heated, stirred, added with sodium hydroxide solution and continued to stir, concentrated by rotary evaporation after suction filtration, washed after suction filtration, and recrystallized after drying to obtain 1H-imidazole-4-carboxylic acid. The present invention has a high yield and a low cost. The above reaction also involves a desulfhydrylation process, and a large amount of waste liquid is generated during the reaction, and there are problems such as many side reactions, poor safety, and high cost.

[0005] In summary, it is necessary to provide a method for preparing 1H-imidazole-4-carboxylic acid with high safety, easy process control, few side reactions and low cost. Summary of the invention

[0006] The technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, a method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst is provided. The present invention uses imidazole-4,5-dicarboxylic acid as a starting raw material, performs a decarboxylation reaction under a self-made catalyst, and synthesizes a target product. The reaction conditions are mild, the process is simple, easy to control, has few side reactions, is highly safe, and greatly improves the purity and yield of the product.

[0007] In order to solve the above technical problems, the technical solution of the present invention is:

[0008] A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst comprises the following steps:

[0009] (1) Preparation of supported copper-based catalyst:

[0010] Add copper nitrate trihydrate to the glucose solution, stir and mix, transfer the obtained reaction solution to an autoclave for reaction, cool the reaction solution to room temperature and filter after the reaction, dry the precipitate, calcine the dried solid in an air atmosphere in a muffle furnace to obtain component A, grind the activated carbon and anhydrous cupric chloride, calcine the obtained mixed powder in a nitrogen atmosphere in a muffle furnace to obtain component B, mix component A and component B to obtain a supported copper-based catalyst;

[0011] (2) Catalytic decarboxylation reaction:

[0012] Add imidazole-4,5-dicarboxylic acid and solvent into a reaction bottle, stir and heat, then add the above catalyst, stir and react once, then slowly heat and stir and react twice, follow the reaction of the raw materials until the reaction is complete, and cool to room temperature;

[0013] (3) Post-processing:

[0014] Deionized water was added to the reaction solution, and the mixture was stirred and washed. The mixture was then cooled to room temperature. The reaction solution was filtered, and the precipitate was washed and dried to obtain the target product 1H-imidazole-4-carboxylic acid.

[0015] Preferably, in step (1), the concentration of the glucose solution is 0.001-0.01 g / ml, and the amount of copper nitrate trihydrate added is 1-3% of the mass of the glucose solution.

[0016] Preferably, in step (1), the stirring and mixing conditions are: 1000-1500 rpm, room temperature, and 1-3 h.

[0017] Preferably, in step (1), the reaction conditions are 120° C. and 10-20 h.

[0018] Preferably, in step (1), the primary calcination temperature is 250° C., the heating rate during calcination is 3-5° C. / min, and the calcination time is 1-2 h.

[0019] Preferably, in step (1), the added amounts of activated carbon and cuprous chloride are 1-3% and 10-20% of the mass of copper nitrate trihydrate, respectively.

[0020] Preferably, in step (1), the conditions for the secondary calcination are: 250° C., a heating rate during calcination of 3-8° C. / min, and a calcination time of 10-12 h.

[0021] Preferably, in step (2), the solvent is dimethylacetamide.

[0022] Preferably, in step (2), the usage ratio of imidazole-4,5-dicarboxylic acid, catalyst and solvent is (30-35) g: (0.01-0.012) g: (60-100) ml.

[0023] Preferably, in step (2), the stirring reaction conditions are: 300-600 rpm, 45-55° C., and 7-8 h.

[0024] Preferably, in step (2), the conditions for the secondary stirring reaction are: 300-600 rpm, 85-95° C., and 7-8 h.

[0025] Preferably, in step (3), the temperature during the stirring and washing treatment is 40-45° C. and the time is 20-30 min.

[0026] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. The present invention provides a novel method for synthesizing 1H-imidazole-4-carboxylic acid, which uses imidazole-4,5-dicarboxylic acid as a starting material and performs decarboxylation to generate a target product under the catalysis of a homemade supported copper-based catalyst. The process is simple, the conditions are mild, and there are few side reactions. With the addition of less catalyst, the yield of the product is as high as more than 95%.

[0028] 2. The supported copper-based catalyst prepared by the present invention uses porous activated carbon as a carrier and cupric oxide and cuprous chloride as catalytic active components, which greatly improves the dispersibility of active components. In the above-mentioned catalyst, cuprous chloride can provide electrons in the reaction and promote the activation of reactants. In the decarboxylation reaction, the presence of cuprous chloride helps to reduce the energy barrier of the reaction and accelerates the occurrence of decarboxylation. Cupric oxide, as a catalyst, has excellent oxidizing ability and can promote the oxidation process of the reaction intermediate. With the assistance of cuprous chloride, cupric oxide can effectively capture the intermediate generated in the reaction, thereby further improving the selectivity of the reaction and the yield of the product. And the surface of cupric oxide contains abundant active sites, which helps the adsorption and activation of the reactants. In a word, cuprous chloride and cupric oxide form a good match in the reaction, so that the catalytic reaction is carried out under relatively mild conditions, ensuring the high yield of the product and the safety of the reaction.

[0029] 3. When preparing a supported copper-based catalyst, the present invention first uses glucose as a carbon template and a reducing agent, and uses copper nitrate trihydrate as a copper source, and reacts under certain conditions to obtain porous carbon-supported copper oxide as component A. Then, activated carbon is used as a reducing agent, and copper chloride is used as a precursor material. The process is carried out at a certain temperature, and the copper chloride is reduced to cuprous chloride to obtain component B. Component A and component B are mixed to obtain a catalyst. The catalyst prepared by the present invention has high catalytic activity and good stability, and still has good catalytic activity after multiple cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 For the target product in Example 1 1 H-NMR spectrum (DMSO, 400 MHz);

[0031] Figure 2 1H-imidazole-4-carboxylic acid standard 1 H-NMR spectrum (DMSO, 400 MHz). DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0035] Unless otherwise specified in the following examples, the raw materials are all commercially available and the conditions are all conventional conditions in the art.

[0036] Activated carbon: 200 mesh, purchased from Chengde Xingyuan Activated Carbon Co., Ltd. (China).

[0037] The product yield is calculated as follows:

[0038] 1H-imidazole-4-carboxylic acid yield (%) = (actual yield / theoretical yield) × 100%.

[0039] Example 1

[0040] A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst comprises the following steps:

[0041] S1. Preparation of supported copper-based catalyst:

[0042] To 60 ml of 0.002 g / ml glucose solution, add copper nitrate trihydrate (the amount added is 1% of the mass of the glucose solution), stir and mix at room temperature and 1000 rpm for 2 h, transfer the obtained reaction solution to an autoclave, react at 120° C. for 12 h, and after the reaction is completed, cool the reaction solution to room temperature and filter, and dry the precipitate;

[0043] The dried solid is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 1h in an air atmosphere to obtain component A. Activated carbon and anhydrous cupric chloride are mixed and ground (the amount of activated carbon and cuprous chloride added is 2% and 15% of the mass of copper nitrate trihydrate, respectively). The obtained mixed powder is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 12h in a nitrogen atmosphere to obtain component B. The obtained component A and component B are mixed to obtain a supported copper-based catalyst;

[0044] S2, catalytic decarboxylation reaction:

[0045] 31 g of imidazole-4,5-dicarboxylic acid and 60 ml of dimethylacetamide were added to a reaction bottle, stirred at 500 rpm and heated to 50° C., then 0.01 g of the above-mentioned supported copper-based catalyst was added, and the reaction was continued for 8 h. The temperature was then raised to 90° C., stirred at 500 rpm and the reaction was continued for 8 h. During the reaction, the reaction of the raw materials was completed, and the reaction was cooled to room temperature to obtain a reaction solution.

[0046] S3, post-processing:

[0047] Add 60 ml of deionized water to the above reaction solution, stir and wash at 300 rpm and 40°C for 30 minutes, then cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain 21.2 g of the target product 1H-imidazole-4-carboxylic acid, with a yield of 95.2%. 1 HNMR (400MHz, DMSO), δ: 7.63 (5-H); 7.73 (2-H).

[0048] from Figure 1 and Figure 2 It can be seen that the product prepared by the present invention is 1H-imidazole-4-carboxylic acid.

[0049] Example 2

[0050] A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst comprises the following steps:

[0051] S1. Preparation of supported copper-based catalyst:

[0052] To 60 ml of 0.009 g / ml glucose solution, add copper nitrate trihydrate (the addition amount is 2% of the mass of the glucose solution), stir and mix at room temperature and 1500 rpm for 3 h, transfer the obtained reaction solution to an autoclave, react at 120° C. for 12 h, and after the reaction is completed, cool the reaction solution to room temperature and filter, and dry the precipitate;

[0053] The dried solid is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 1h in an air atmosphere to obtain component A, activated carbon and anhydrous cupric chloride are mixed and ground (the amount of activated carbon and cuprous chloride added is 3% and 15% of the mass of copper nitrate trihydrate, respectively), and the obtained mixed powder is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 12h in a nitrogen atmosphere to obtain component B, and the obtained component A and component B are mixed to obtain a supported copper-based catalyst;

[0054] S2, catalytic decarboxylation reaction:

[0055] 31 g of imidazole-4,5-dicarboxylic acid and 60 ml of dimethylacetamide were added to a reaction bottle, stirred at 500 rpm and heated to 50° C., then 0.011 g of the above-mentioned supported copper-based catalyst was added, and the reaction was continued for 8 h, and then the temperature was raised to 90° C., stirred at 500 rpm and reacted for 8 h. During the reaction, the reaction of the raw materials was completed, and the mixture was cooled to room temperature to obtain a reaction solution;

[0056] S3, post-processing:

[0057] Add 60 ml of deionized water to the reaction solution, stir and wash at 300 rpm and 42° C. for 30 min, then cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain 21.3 g of the target product 1H-imidazole-4-carboxylic acid with a yield of 95.5%.

[0058] Example 3

[0059] A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst comprises the following steps:

[0060] S1. Preparation of supported copper-based catalyst:

[0061] To 60 ml of 0.008 g / ml glucose solution, add copper nitrate trihydrate (the addition amount is 3% of the mass of the glucose solution), stir and mix at room temperature and 1200 rpm for 3 h, transfer the obtained reaction solution to an autoclave, react at 120° C. for 12 h, and after the reaction is completed, cool the reaction solution to room temperature and filter, and dry the precipitate;

[0062] The dried solid is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 1h in an air atmosphere to obtain component A. Activated carbon and anhydrous cupric chloride are mixed and ground (the amount of activated carbon and cuprous chloride added is 2% and 20% of the mass of copper nitrate trihydrate, respectively). The obtained mixed powder is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 12h in a nitrogen atmosphere to obtain component B. The obtained component A and component B are mixed to obtain a supported copper-based catalyst;

[0063] S2, catalytic decarboxylation reaction:

[0064] 31 g of imidazole-4,5-dicarboxylic acid and 60 ml of dimethylacetamide were added to a reaction bottle, stirred at 500 rpm and heated to 50° C., then 0.012 g of the above-mentioned supported copper-based catalyst was added, and the reaction was continued for 8 h. The temperature was then raised to 90° C., stirred at 500 rpm and the reaction was continued for 8 h. During the reaction, the reaction of the raw materials was completed, and the reaction was cooled to room temperature to obtain a reaction solution.

[0065] S3, post-processing:

[0066] Add 60 ml of deionized water to the above reaction solution, stir and wash at 300 rpm and 45°C for 30 minutes, then cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain 21.4 g of the target product 1H-imidazole-4-carboxylic acid, with a yield of 96.0%.

[0067] Example 4

[0068] A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst comprises the following steps:

[0069] S1. Preparation of supported copper-based catalyst:

[0070] To 60 ml of 0.009 g / ml glucose solution, add copper nitrate trihydrate (the addition amount is 3% of the mass of the glucose solution), stir and mix at room temperature and 1400 rpm for 3 h, transfer the obtained reaction solution to an autoclave, react at 120° C. for 12 h, and after the reaction, cool the reaction solution to room temperature and filter, and dry the precipitate;

[0071] The dried solid is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 1h in an air atmosphere to obtain component A, activated carbon and anhydrous cupric chloride are mixed and ground (the amount of activated carbon and cuprous chloride added is 3% and 20% of the mass of copper nitrate trihydrate, respectively), and the obtained mixed powder is placed in a muffle furnace, heated to 250°C at a rate of 5°C / min, and calcined for 12h in a nitrogen atmosphere to obtain component B, and the obtained component A and component B are mixed to obtain a supported copper-based catalyst;

[0072] S2, catalytic decarboxylation reaction:

[0073] 31 g of imidazole-4,5-dicarboxylic acid and 60 ml of dimethylacetamide were added to a reaction bottle, stirred at 600 rpm and heated to 50° C., then 0.012 g of the above-mentioned supported copper-based catalyst was added, and the reaction was continued for 8 h, and then the temperature was raised to 90° C., stirred at 600 rpm and reacted for 8 h. During the reaction, the reaction of the raw materials was completed, and the reaction was cooled to room temperature to obtain a reaction solution;

[0074] S3, post-processing:

[0075] Add 60 ml of deionized water to the reaction solution, stir and wash at 300 rpm and 45° C. for 30 min, then cool to room temperature, filter the reaction solution, wash the precipitate and dry it to obtain 21.5 g of the target product 1H-imidazole-4-carboxylic acid with a yield of 96.5%.

[0076] In order to better verify that the technical solution of the present invention has a better effect, Example 4 is used as a reference and further explained in combination with multiple comparative examples.

[0077] Comparative Example 1

[0078] Compared with Example 4, the difference is that commercially available cuprous chloride and cupric oxide are directly used for compounding, the usage ratio of cuprous chloride and cupric oxide and other conditions are the same as those in Example 4, and the target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 94.9%.

[0079] Comparative Example 2

[0080] Compared with Example 4, the difference is that in step S1, the addition amount of copper nitrate trihydrate is 0.5% of the mass of the glucose solution, and the other conditions are the same as those in Example 4. The target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 90.9%.

[0081] Comparative Example 3

[0082] Compared with Example 4, the difference is that in step S1, in the preparation of component A, the calcination time is 5 hours, and the other conditions are the same as those in Example 4, and the target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 88.3%.

[0083] Comparative Example 4

[0084] Compared with Example 4, the difference is that in step S1, the heating rate in the preparation of component A is 10°C / min, and the other conditions are the same as those in Example 4, and the target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 90.1%.

[0085] Comparative Example 5

[0086] Compared with Example 4, the difference is that in step S1, the calcination time in the preparation of component B is 15 hours, and the other conditions are the same as those in Example 4, and the target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 89.9%.

[0087] Comparative Example 6

[0088] Compared with Example 4, the difference is that in step S1, the catalyst only includes component A, and the other conditions are the same as those in Example 4, and the target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 80.5%.

[0089] Comparative Example 7

[0090] Compared with Example 4, the difference is that in step S1, the catalyst only includes component B, and the other conditions are the same as those in Example 4, and the target product 1H-imidazole-4-carboxylic acid is obtained with a yield of 51.2%.

[0091] In summary, when preparing the catalyst, the amount of glucose, calcination time, calcination temperature, etc. will affect the activity of the catalyst. If the mass ratio of glucose to copper nitrate trihydrate is too large and the calcination time is too long, more metal will be formed during calcination, the amount of copper oxide or cuprous chloride generated will be reduced, and the catalytic activity of the catalyst will be reduced. The present invention optimizes the above preparation conditions to obtain a catalyst with high catalytic activity. When used for synthesizing 1H-imidazole-4-carboxylic acid, a high yield of the target product can be obtained under relatively mild conditions.

[0092] In order to verify the cyclic stability of the catalyst of the present invention, the supported catalyst prepared in Example 4 was recycled 10 times and then reused in the preparation of 1H-imidazole-4-carboxylic acid. The specific preparation method was the same as that in Example 4, and 21.1 g of 1H-imidazole-4-carboxylic acid was obtained, and the product yield was 95.0%. It can be seen that the supported copper-based catalyst prepared by the present invention still has good catalytic activity after being recycled 10 times.

[0093] 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 preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst, characterized in that: The following steps are involved: (1) Preparation of supported copper-based catalyst: Add copper nitrate trihydrate to the glucose solution, stir and mix, transfer the obtained reaction solution to an autoclave for reaction, cool the reaction solution to room temperature and filter after the reaction, dry the precipitate, calcine the dried solid in an air atmosphere in a muffle furnace to obtain component A, grind anhydrous copper chloride and activated carbon, calcine the obtained mixed powder in a nitrogen atmosphere in a muffle furnace to obtain component B, and mix component A and component B to obtain a supported copper-based catalyst; (2) Catalytic decarboxylation reaction: Add imidazole-4,5-dicarboxylic acid and solvent into a reaction bottle, stir and heat, then add the above catalyst, stir and react once, then slowly heat and stir and react twice, follow the reaction of the raw materials until the reaction is complete, and cool to room temperature; (3) Post-processing: Deionized water was added to the reaction solution, and the mixture was stirred and washed. The mixture was then cooled to room temperature. The reaction solution was filtered, and the precipitate was washed and dried to obtain the target product 1H-imidazole-4-carboxylic acid.

2. A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (1), the concentration of the glucose solution is 0.001-0.01 g / ml, and the amount of copper nitrate trihydrate added is 1-3% of the mass of the glucose solution.

3. A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (1), the stirring and mixing conditions are: 1000-1500 rpm, room temperature, and 1-3 h.

4. A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (1), the reaction conditions are 120° C. and 10-20 h.

5. A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (1), the primary calcination temperature is 250° C., the heating rate during calcination is 3-5° C. / min, and the calcination time is 1-2 h.

6. A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (1), the added amounts of activated carbon and cuprous chloride are 1-3% and 10-20% of the mass of copper nitrate trihydrate.

7. A method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (1), the conditions for the secondary calcination are: 250° C., a heating rate during calcination of 3-8° C. / min, and a calcination time of 10-12 h.

8. The method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (2), the solvent is dimethylacetamide, and the usage ratio of imidazole-4,5-dicarboxylic acid, catalyst and solvent is (30-35) g: (0.01-0.012) g: (60-100) ml.

9. The method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (2), the stirring reaction conditions are: 300-600 rpm, 45-55° C., 7-8 h; The conditions of the secondary stirring reaction are: 300-600 rpm, 85-95° C., 7-8 h.

10. The method for preparing 1H-imidazole-4-carboxylic acid based on a supported copper-based catalyst according to claim 1, characterized in that: In step (3), the temperature during the stirring and washing treatment is 40-45° C. and the time is 20-30 min.

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