Method for preparing primary diamine
The preparation of binary primary amines by reducing amination in the ammonia and hydrogen atmosphere by Rainey nickel and Rainey cobalt catalysts is solved, and the problems of high energy consumption, high cost and low selectivity in the prior art are achieved, and high efficiency and low cost preparation of binary primary amines is achieved, which is suitable for industrial production.
Patent Information
- Application Number
- CN202410131202.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-30
- Publication Date
- 2025-08-01
AI Technical Summary
The existing dinitrile hydrogenation method has the problems of high energy consumption, high raw materials, low product selectivity, complex process flow, and the three dicarboxylic acid substrates mainly generate cyclization products during reduction and amination, and the catalyst cost is high.
Using Rainey nickel and/or Rainey cobalt catalysts, a binary primary amine is prepared by a one-step reduction amination reaction under a mixed atmosphere of ammonia and hydrogen. Ether and alcohol ether solvents are used to control the reaction conditions such as temperature, pressure and catalyst ratio, so as to achieve efficient conversion of dicarboxylic acids and product selectivity.
It realizes high selective preparation of binary primary amines, with simple process and no toxic intermediate products, low production cost, easy industrialization, and good environmental and economic benefits.
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Figure CN120398693A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the fields of green chemistry and catalysis, and in particular, to a method for preparing a dibasic primary amine. Background Art
[0002] Dibasic primary amines are important organic raw materials. Existing methods for preparing diamines mainly involve the hydrogenation of corresponding dinitriles. The preparation process of dinitriles has problems such as high energy consumption, highly toxic raw materials, low product selectivity, and complex process flow. Reductive amination is commonly used for the conversion of aldehydes or alcohols to prepare primary amine compounds. Currently, there are few research reports on the reaction process of directly reductive amination of diacids to prepare diamines. Coeck et al. first reported the reaction of one-pot reductive amination of carboxylic acids to prepare primary amines, with the main reaction substrate being monocarboxylic acids and a high yield of monobasic primary amines; however, when three dibasic carboxylic acid substrates are subjected to reductive amination, mainly cyclic products such as lactams or cyclic secondary amines are formed, and the yield of the products is very low. Moreover, the catalyst is an expensive Ru-based catalyst, with a high preparation cost. Summary of the Invention
[0003] The object of the present disclosure is to provide a method for preparing a dibasic primary amine, which has a simple process, no highly toxic intermediate products, low production costs, high production efficiency, and is easy to industrialize.
[0004] To achieve the above object, the present disclosure provides a method for preparing a dibasic primary amine, the method comprising:
[0005] bringing a dibasic carboxylic acid, a catalyst, and a solvent into contact in a closed container, and reacting under a mixed atmosphere of ammonia and hydrogen;
[0006] wherein the dibasic carboxylic acid is an aliphatic dibasic carboxylic acid; the catalyst is Raney nickel and / or Raney cobalt.
[0007] Optionally, the aliphatic dibasic carboxylic acid is selected from one or more of succinic acid, adipic acid, suberic acid, sebacic acid, and azelaic acid; the catalyst is Raney nickel.
[0008] Optionally, the method comprises mixing the dibasic carboxylic acid with the solvent to form a dibasic carboxylic acid solution, and then bringing it into contact with the catalyst for the reaction; the mass concentration of the dibasic carboxylic acid solution is 20 - 40%, preferably 25 - 35%.
[0009] Optionally, the pressure of the ammonia is 0.7 - 2.0 MPa, preferably 0.7 - 1.0 Mpa.
[0010] Optionally, the pressure of the hydrogen is 0.1 - 1 MPa, preferably 0.3 - 0.7 Mpa.
[0011] Optionally, the mass ratio of the dicarboxylic acid to the catalyst is 100:5 - 25, preferably 100:8 - 15.
[0012] Optionally, the reaction conditions include a reaction temperature of 190 - 280°C, preferably 190 - 250°C; and a reaction time of 20 - 50 h, preferably 20 - 30 h.
[0013] Optionally, before starting the reaction, the method further includes heating the reaction system to the reaction temperature at a rate of 1 - 5°C / min; the rate is preferably 2 - 3°C / min.
[0014] Optionally, the solvent includes one or more of ether solvents and alcohol - ether solvents.
[0015] Optionally, the solvent is selected from one or more of propylene glycol methyl ether, propylene glycol ethyl ether, cyclopentyl methyl ether, and isopropyl ether.
[0016] Through the above - mentioned technical solution, the present disclosure uses a Raney cobalt / nickel catalyst to prepare a secondary primary amine by one - step reductive amination under a reducing atmosphere containing ammonia and hydrogen, and the selectivity of the product is high. The method of the present disclosure has a simple process, no highly toxic intermediate products, low production costs, high production efficiency, and is easy to industrialize.
[0017] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification. They are used to explain the present disclosure together with the following specific implementation, but do not constitute a limitation to the present disclosure. In the drawings:
[0019] Figure 1 is the mass spectrum of hexamethylenediamine in Example 1 of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION
[0020] The following will describe in detail the specific implementation of the present disclosure with reference to the drawings. It should be understood that the specific implementation described herein is only for explaining and understanding the present disclosure, and is not used to limit the present disclosure.
[0021] The present disclosure provides a method for preparing a secondary primary amine, and the method includes:
[0022] Bringing a dicarboxylic acid, a catalyst, and a solvent into contact in a closed container, and carrying out a reaction under a mixed atmosphere of ammonia and hydrogen;
[0023] wherein, the dicarboxylic acid is an aliphatic dicarboxylic acid; the catalyst is Raney nickel and / or Raney cobalt.
[0024] Under a reducing atmosphere containing ammonia and hydrogen, a binary primary amine is prepared by one-step reductive amination using a Raney nickel / cobalt catalyst, and the selectivity of the product is high. The method of the present disclosure has a simple process, no highly toxic intermediate products, low production costs, high production efficiency, and is easy to industrialize.
[0025] According to an embodiment of the present disclosure, the dicarboxylic acid is selected from one or more of succinic acid, adipic acid, suberic acid, sebacic acid, and azelaic acid; the catalyst is Raney nickel. The above embodiment is beneficial to the product having higher selectivity.
[0026] According to an embodiment of the present disclosure, the method includes mixing the dicarboxylic acid with the solvent to form a dicarboxylic acid solution, and then contacting with the catalyst to carry out the reaction; the mass concentration of the dicarboxylic acid solution is 20-40%, preferably 25-35%. The above embodiment is beneficial to the product having higher selectivity.
[0027] According to an embodiment of the present disclosure, the pressure of the ammonia is 0.7-2 MPa, preferably 0.7-1.0 Mpa. The pressure of the hydrogen is 0.1-1 MPa, preferably 0.3-0.7 Mpa. The above embodiment is beneficial to the dicarboxylic acid having a higher conversion rate and the product having higher selectivity.
[0028] According to an embodiment of the present disclosure, the mass ratio of the dicarboxylic acid to the catalyst is 100:5-25, preferably 100:8-15. The above embodiment is beneficial to the product having higher selectivity.
[0029] According to an embodiment of the present disclosure, the reaction conditions include a reaction temperature of 190-280 °C, preferably 190-250 °C; the reaction time is 20-50 h, preferably 20-30 h. The above embodiment is beneficial to the dicarboxylic acid having a higher conversion rate and the product having higher selectivity.
[0030] According to an embodiment of the present disclosure, before starting the reaction, the method may include heating the reaction system from a temperature T1 to the reaction temperature at a rate of 1-5 °C / min; the T1 is 20-60 °C; the rate is preferably 2-3 °C / min. The above embodiment is beneficial to the product having higher selectivity.
[0031] According to an embodiment of the present disclosure, the solvent includes one or more of ether solvents and alcohol ether solvents; the ether solvent may be selected from ethers of C3-C8; the alcohol ether solvent may be selected from alcohol ethers of C3-C8; in a further embodiment, the solvent is selected from one or more of propylene glycol methyl ether, propylene glycol ethyl ether, cyclopentyl methyl ether, and isopropyl ether. The above embodiment is beneficial to the product having higher selectivity.
[0032] According to the present disclosure, the qualitative analysis of the product is carried out by high - performance gas chromatography; the quantitative analysis is carried out by the external standard method.
[0033] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereby.
[0034] In the examples, the Raney nickel used was purchased from MACKLIN company, with the product number R817297, 50μm; the Raney cobalt used was purchased from MACKLIN company, with the product number R817300, 50μm; the Ru / C catalyst used was purchased from Shanghai Aladdin company, with the product number A58343. Unless otherwise specified, the remaining chemical reagents used in the examples are all commercially available products.
[0035] In the examples of the present disclosure, the high - performance gas chromatography analysis was carried out on an instrument of model Thermo Scientific Trace1300; the mass spectrometry analysis was carried out on an instrument of model Thermo Scientific ISQ 7000.
[0036] Example 1
[0037] Take 20.00 g of adipic acid and dissolve it in 37.14 g of cyclopentyl methyl ether (the mass fraction of adipic acid in the solution is 35%). After mixing evenly, add it to a high - pressure reactor, and add 2.6 g of Raney nickel catalyst to the reactor. After repeatedly displacing the gas in the high - pressure reactor with nitrogen 3 times, introduce 0.7 MPa of ammonia and 0.5 MPa of hydrogen. Within 1.2 hours, the temperature of the reactor is raised from 35°C to 200°C, with a heating rate of 2.3°C / min, and react at 200°C for 23 hours. In this reaction, the mass ratio of adipic acid to Raney nickel is 100:13. After the reaction is completed, take out the reaction solution for testing, and the conversion rate of adipic acid is analyzed to be 99.9%, and the selectivity of hexamethylenediamine is 46.5%.
[0038] Example 2
[0039] Take 20.00 g of adipic acid and dissolve it in 60.00 g of propylene glycol methyl ether (the mass fraction of adipic acid in the solution is 25%). After mixing evenly, add it to a high - pressure reactor, and add 1.6 g of Raney cobalt catalyst to the reactor. After repeatedly displacing the gas in the high - pressure reactor with nitrogen 3 times, introduce 0.9 MPa of ammonia and 0.6 MPa of hydrogen; within 1.4 hours, the temperature of the reactor is raised from 35°C to 230°C, with a heating rate of 2.3°C / min, and react at 230°C for 20 hours. In this reaction, the mass ratio of adipic acid to Raney cobalt is 100:8. After the reaction is completed, take out the reaction solution for testing, and the conversion rate of adipic acid is analyzed to be 99.9%, and the selectivity of hexamethylenediamine is 39.8%.
[0040] Example 3
[0041] Dissolve 20.00 g of succinic acid in 46.67 g of cyclopentyl methyl ether (the mass fraction of succinic acid in the solution is 30%). After mixing evenly, add it to a high-pressure reactor, and add 2.4 g of Raney nickel catalyst to the reactor. After repeatedly displacing the gas in the high-pressure reactor with nitrogen 3 times, introduce 0.8 MPa of ammonia and 0.6 MPa of hydrogen. Within 1.2 hours, the temperature of the reactor is raised from 35 °C to 215 °C, and the heating rate is 2.5 °C / min. React at 215 °C for 24 hours. In this reaction, the mass ratio of succinic acid to Raney nickel is 100:12. After the reaction is completed, take out the reaction solution for testing, and analyze that the conversion rate of succinic acid is 99.9%, and the selectivity of diamine is 52.6%.
[0042] Example 4
[0043] This example is the same as Example 1, except that the catalyst in this example is Raney cobalt. After the reaction is completed, take out the reaction solution for testing, and analyze that the conversion rate of adipic acid is 99.9%, and the selectivity of hexamethylenediamine is 16.9%.
[0044] Example 5
[0045] This example is the same as Example 1, except that the pressure of ammonia in this example is 1.2 MPa. After the reaction is completed, take out the reaction solution for testing, and analyze that the conversion rate of adipic acid is 87.6%, and the selectivity of hexamethylenediamine is 24.3%.
[0046] Example 6
[0047] This example is the same as Example 1, except that the pressure of hydrogen in this example is 1.0 MPa. After the reaction is completed, take out the reaction solution for testing, and analyze that the conversion rate of adipic acid is 99.9%, and the selectivity of hexamethylenediamine is 18.6%.
[0048] Example 7
[0049] This example is the same as Example 1, except that the amount of Raney nickel catalyst used in this example is 4.0 g, and the mass ratio of adipic acid to Raney nickel is 100:20. After the reaction is completed, take out the reaction solution for testing, and analyze that the conversion rate of adipic acid is 99.9%, and the selectivity of hexamethylenediamine is 22.8%.
[0050] Example 8
[0051] 20.00 g of adipic acid was dissolved in 37.14 g of cyclopentyl methyl ether (the mass fraction of adipic acid in the solution was 35%). After mixing evenly, it was added to a high-pressure reactor, and 2.6 g of Raney nickel catalyst was added to the reactor. After repeatedly displacing the gas in the high-pressure reactor with nitrogen 3 times, 0.7 MPa of ammonia and 0.5 MPa of hydrogen were introduced. Within 54 minutes, the temperature of the reactor was raised from 35 °C to 160 °C at a heating rate of 2.3 °C / min, and the reaction was carried out at 160 °C for 23 hours. In this reaction, the mass ratio of adipic acid to Raney nickel was 7.7:1. After the reaction was completed, the reaction solution was taken out for testing. The conversion rate of adipic acid was analyzed to be 79.6%, and the selectivity of hexamethylenediamine was 8.9%.
[0052] Comparative Example 1
[0053] 20.00 g of adipic acid was dissolved in 37.14 g of cyclopentyl methyl ether (the mass fraction of adipic acid in the solution was 35%). After mixing evenly, it was added to a high-pressure reactor, and 2.6 g of Ru / C catalyst was added to the reactor. After repeatedly displacing the gas in the high-pressure reactor with nitrogen 3 times, 0.7 MPa of ammonia and 0.5 MPa of hydrogen were introduced. Within 1.2 hours, the temperature of the reactor was raised from 35 °C to 200 °C at a heating rate of 2.3 °C / min, and the reaction was carried out at 200 °C for 23 hours. In this reaction, the mass ratio of adipic acid to Ru / C was 7.7:1. After the reaction was completed, the reaction solution was taken out for testing. The conversion rate of adipic acid was analyzed to be 99.9%, and the selectivity of hexamethylenediamine was 2.1%.
[0054] Table 1
[0055] Conversion rate of aliphatic dicarboxylic acid / % Selectivity of product / % Example 1 99.9 46.5 Example 2 99.9 39.8 Example 3 99.9 52.6 Example 4 99.9 16.9 Example 5 87.6 24.3 Example 6 99.9 18.6 Example 7 99.9 22.8 Example 8 79.6 8.9 Comparative Example 1 99.9 2.1
[0056] According to the data in Table 1, it can be seen that the method of the present disclosure realizes the one-step preparation of dibasic primary amines from dibasic carboxylic acids through catalytic hydroamination with Raney nickel or Raney cobalt. The catalyst of the present disclosure uses non-precious metals, has low cost and is non-toxic. The reaction process is simple, the post-treatment of the product is simple, there is no highly toxic intermediate product, the production cost is low, the production efficiency is high, and the selectivity of the product is high, which is easy to industrialize and has good environmental and economic benefits. By comparing Example 1 with Example 4, it can be seen that under the preferred catalyst of the present disclosure, the selectivity of the reaction product is higher. By comparing Example 1 with Example 5, it can be seen that within the pressure range of ammonia of the present disclosure, the conversion rate of dibasic carboxylic acid is higher and the selectivity of the reaction product is higher. By comparing Example 1 with Example 6, it can be seen that within the pressure range of hydrogen of the present disclosure, the selectivity of the reaction product is higher. By comparing Example 1 with Example 7, it can be seen that within the preferred mass ratio range of dibasic carboxylic acid to catalyst of the present disclosure, the selectivity of the reaction product is higher. By comparing Example 1 with Example 8, it can be seen that within the reaction temperature range of the present disclosure, the conversion rate of dibasic carboxylic acid is higher and the selectivity of the reaction product is higher.
[0057] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.
[0058] In addition, it should be noted that, in the above specific embodiments, the various specific technical features described can be combined in any suitable manner without conflict. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination manners.
[0059] Furthermore, any combination can be made among the various different embodiments of the present disclosure as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.
Claims
1. A method for preparing a secondary diamine, characterized in that, The method comprises the following steps: Contacting a dicarboxylic acid, a catalyst and a solvent in a closed container and carrying out a reaction under a mixed atmosphere of ammonia gas and hydrogen gas; Wherein, the dicarboxylic acid is an aliphatic dicarboxylic acid; the catalyst is Raney nickel and / or Raney cobalt.
2. The method according to claim 1, wherein, The aliphatic dicarboxylic acid is selected from one or more of succinic acid, adipic acid, suberic acid, sebacic acid and azelaic acid; the catalyst is Raney nickel.
3. The method according to claim 1, wherein, The method comprises mixing the dicarboxylic acid with the solvent to form a dicarboxylic acid solution, and then contacting with the catalyst to carry out the reaction; the mass concentration of the dicarboxylic acid solution is 20-40%, preferably 25-35%.
4. The method according to claim 1, wherein, The pressure of the ammonia gas is 0.7-2.0 MPa, preferably 0.7-1.0 Mpa.
5. The method according to claim 1, wherein The pressure of the hydrogen gas is 0.1-1 MPa, preferably 0.3-0.7 Mpa.
6. The method according to claim 1, wherein The mass ratio of the dicarboxylic acid to the catalyst is 100:5-25, preferably 100:8-15.
7. The method according to claim 1, wherein, The reaction conditions include a reaction temperature of 190-280 °C, preferably 190-250 °C; the reaction time is 20-50 h, preferably 20-30 h.
8. The method according to claim 7, wherein Before starting the reaction, the method further comprises heating the reaction system to the reaction temperature at a rate of 1-5 °C / min; the rate is preferably 2-3 °C / min.
9. The method according to claim 1, wherein, The solvent includes one or more of ether solvents and alcohol ether solvents.
10. The method according to claim 9, wherein, The solvent is selected from one or more of propylene glycol methyl ether, propylene glycol ethyl ether, cyclopentyl methyl ether and isopropyl ether.