Green synthesis method of alkoxy propylamine
Through the process of alkoxypropylamine synthesis, the Michael addition reaction catalyzed by composite organic base and the continuous flow hydrogenation process of copper and nickel bimetal supported catalysts in the prior art is solved, and the effects of green synthesis and the applicability of industrial applications are achieved.
Patent Information
- Application Number
- CN202510067026.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-15
- Publication Date
- 2025-04-25
AI Technical Summary
In the existing alkoxypropylamine synthesis technology, the first step is easy to fly temperature and there are many by-products, and the second step is high in production safety risks.
The Michael addition reaction system catalyzed by a composite organic base is used to catalyze acrylonitrile. The alkyl alcohol participates in the reaction as both solvents and reactants, reducing the cost of raw materials and by-product content; in the second step of nitrile hydrogenation reaction, copper and nickel bimetal supported catalysts and continuous flow hydrogenation processes are used to replace the traditional Rainey nickel catalyst and reactor hydrogenation process to reduce production safety risks.
The first step of reaction conditions is achieved with gentleness and low by-product generation, and the second step of reaction safety and production cost is improved, which is suitable for modular and industrial applications.
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Abstract
Description
Technical Field
[0001] The present application relates to a green synthesis method of alkoxypropylamine, belonging to the technical field of fine chemical preparation. Background Art
[0002] Alkoxypropylamine is an important primary amine, belonging to an organic compound, which has an alkoxy group connected to the main chain of propylamine. One of its main applications is in the field of organic synthesis. It is an important intermediate in the production of various drugs and agricultural chemicals, and can be widely used in the field of fine chemical preparation. For example, 3-methoxypropylamine (MOPA) is a widely used primary amine compound, mainly used as a mineral flotation agent, and its selectivity for iron ore flotation is higher than that of ordinary surfactants. In addition, 3-methoxypropylamine can be used as an important intermediate for the synthesis of dyes such as dispersed turquoise blue S-GL, and can also be widely used in metal corrosion inhibitor formulations, with the formulation dosage accounting for 5-15% of the total mass of the formulation. Corrosion inhibitors are gradually being promoted and applied in the field of petrochemicals, giving 3-methoxypropylamine a good application prospect.
[0003] 3-Ethoxypropylamine (EOPA) can be used as an intermediate for the synthesis of disperse dye 90# red, and can also be gradually introduced into the petrochemical industry as a new external corrosion inhibitor and ion emulsifier for promotion and application. Now it is also widely used in integrated circuits, OLEDs, mobile phone displays and other fields, and has a wide range of market uses.
[0004] The traditional synthesis method adopted in the prior art for preparing alkoxypropylamine has problems in the two-step reaction: when synthesizing alkoxypropionitrile in the first step, it is difficult to control the reaction temperature for the addition of acrylonitrile and hydroxyl groups, and a large amount of polymers are often produced, with more by-products and a low product yield. In the second step of the nitrile hydrogenation reaction step, the reactor has problems such as low yield, large catalyst loss, high production cost, flammable Raney nickel in the air, and explosiveness of high-pressure hydrogen reactor in combination with Raney nickel hydrogenation. Therefore, the scope of application of the reaction is severely limited, the reaction conditions are harsh, the industrial production safety risk is increased, and the technology development and production costs are also increased. Summary of the invention
[0005] In order to solve the problems existing in the prior art of the synthesis of alkoxypropylamines mentioned above that "the first step reaction is prone to overheating, there are many by-products, and the second step reaction has a high production safety risk", the present application provides a technical solution for the green synthesis of alkoxypropylamines. In the first step addition reaction, a composite organic base is used to catalyze the Michael addition reaction system of acrylonitrile, and alkyl alcohol participates in the reaction as both a solvent and a reactant, which greatly reduces the cost of raw materials, mild catalytic conditions, and extremely low by-product content; in the second step nitrile hydrogenation reaction, a copper and nickel bimetallic supported catalyst is used instead of the traditional Raney nickel catalyst system, and a continuous flow hydrogenation process is used instead of the traditional reactor hydrogenation process to reduce production safety risks. The alkoxypropylamines prepared by the technical solution provided in the present application are suitable for modular and industrial applications.
[0006] This application adopts the following technical solutions:
[0007] The present application provides a green synthesis method of alkoxypropylamine, comprising the following steps:
[0008] S1, subjecting a raw material liquid containing an alkyl alcohol, acrylonitrile, and a composite organic base catalyst to a Michael addition reaction to obtain a reaction liquid containing an alkoxypropionitrile;
[0009] S2. In a mixed atmosphere of hydrogen and alkaline auxiliary agent, the reaction solution obtained in step S1 is continuously contacted with a copper / nickel bimetallic supported catalyst to carry out a hydrogenation reaction to obtain the alkoxypropylamine.
[0010] Optionally, in step S2, the hydrogenation reaction is carried out in a micro-filled reactor, and a copper / nickel bimetallic supported catalyst is loaded in the reactor.
[0011] Optionally, in step S1, the composite organic base catalyst includes an organic base and an inorganic base.
[0012] The organic base is selected from at least one of sodium tert-butoxide, potassium tert-butoxide and lithium tert-butoxide;
[0013] The inorganic base is selected from at least one of potassium carbonate, cesium carbonate, sodium hydroxide and potassium hydroxide.
[0014] Optionally, the organic base is preferably sodium tert-butoxide.
[0015] Preferably, the weight ratio of the organic base to the inorganic base is 1:0.6-1.3.
[0016] The system can be adjusted by adding the inorganic base potassium carbonate. The Lewis acid / base pair synergistically catalyzes and reduces the side reaction of acrylonitrile addition, effectively alleviating the temperature rise of the reaction.
[0017] Optionally, in step S2, the copper / nickel bimetallic supported catalyst comprises an active component and a carrier;
[0018] The active component is loaded on the carrier;
[0019] The active components include active component I and active component II;
[0020] The active component I comprises metallic nickel, and the loading amount of the metallic nickel in the copper / nickel bimetallic supported catalyst is 4-7 wt%;
[0021] The active component II includes metallic copper, and the loading amount of the metallic copper in the copper / nickel bimetallic supported catalyst is 10-15 wt%.
[0022] Optionally, the carrier is alumina;
[0023] Optionally, the copper / nickel bimetallic supported catalyst is obtained by impregnating a carrier in a solution containing active components, calcining at high temperature, and reducing in a hydrogen atmosphere.
[0024] Optionally, the solution of the active component is obtained by mixing a Cu salt and a Ni salt with water, and the salt is selected from at least one of nitrate, acetate, and hydrochloride;
[0025] The immersion conditions include: immersion at 10-30° C. for 12-18 hours;
[0026] The high temperature calcination conditions include: calcination at 320-380°C for 4-8h in air atmosphere;
[0027] The reduction conditions are: heating at 350-500°C for 8-16h under hydrogen atmosphere.
[0028] Optionally, in step S2, the continuous contact conditions include: the mass space velocity of the reaction liquid is 0.5 to 1.5 h -1 .
[0029] Optionally, in step S2, the continuous contact conditions include: the mass space velocity of the reaction liquid is 0.5h -1 、0.6h -1 、0.7h -1 、0.8h -1 、0.9h -1 , 1h -1 , 1.1h -1 , 1.2h -1 , 1.3h -1 , 1.4h -1 , 1.5h -1 , or any range of values between them.
[0030] Optionally, in step S2, the conditions of the hydrogenation reaction include: a reaction temperature of 70 to 200° C., and a reaction pressure of 3 to 7 MPa in terms of hydrogen partial pressure.
[0031] Optionally, in step S2, the conditions of the hydrogenation reaction include: a reaction temperature of 80 to 120° C., and a reaction pressure of 4 to 5 MPa in terms of hydrogen partial pressure.
[0032] Optionally, the hydrogen flow rate is 30 to 60 mL / min.
[0033] Optionally, the flow rate of the alkaline auxiliary agent is 0.1 to 0.3 mL / min.
[0034] Optionally, in step S2, the alkaline auxiliary agent is selected from NH 3 , triethylamine, and diisopropylethylamine.
[0035] The alkaline additive is NH 3 When the liquid ammonia is pressurized separately, it is injected by the injection pump, mixed with hydrogen and then enters the reaction system. When the alkaline auxiliary agent is at least one of triethylamine and diisopropylethylamine, it is mixed with the reaction liquid and enters the reaction system together.
[0036] Optionally, in step S2, the molar ratio of the alkoxypropionitrile to the alkaline auxiliary agent in the reaction solution is 1:10-20.
[0037] Optionally, in step S2, the molar ratio of the alkoxypropionitrile in the reaction solution to the alkaline auxiliary agent is selected from any value of 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, or any range between the two.
[0038] Optionally, in step S1, the weight ratio of acrylonitrile to the composite organic base catalyst is 1:0.001-0.005.
[0039] Optionally, the alkyl alcohol is independently selected from at least one of methanol, ethanol, propanol, isopropanol, butanol and the like.
[0040] Optionally, in step S1, the molar ratio of the alkyl alcohol to acrylonitrile is 2 to 5:1.
[0041] Optionally, in step S1, the conditions of the Michael addition reaction include: a reaction temperature of -10 to 30°C, and a reaction time of 2 to 10 hours.
[0042] Optionally, in step S1, the raw material solution is prepared by the following method:
[0043] The temperature of the mixed solution containing the alkyl alcohol and the composite organic base catalyst is lowered to -10 to 10°C, and then acrylonitrile is added dropwise to the mixed solution. After the addition is completed, the temperature is naturally raised to room temperature to obtain the raw material solution.
[0044] Optionally, the dropping speed is 3 to 10 mL / min.
[0045] Optionally, the temperature of the mixed solution is reduced to -5 to 5°C.
[0046] Optionally, the alkyl alcohol is independently selected from at least one of methanol, ethanol, propanol, isopropanol, n-butanol and the like.
[0047] The beneficial effects of this application include:
[0048] The green synthesis method of alkoxypropylamine provided by the present application, in the first step of the addition coupling reaction, the composite organic base catalyzes the Michael addition reaction of acrylonitrile, and the alkyl alcohol participates in the reaction as both a solvent and a reactant, which greatly reduces the cost of raw materials, the catalytic conditions are mild, and the by-product content is extremely low; in the second step of the nitrile hydrogenation reaction, a copper / nickel bimetallic supported catalyst is used to replace the traditional Raney nickel catalyst system, and a continuous flow hydrogenation process is used to replace the traditional reactor hydrogenation process to reduce production safety risks. The alkoxypropylamine prepared by the technical solution provided by the present application is suitable for modular and industrial applications. The raw material alkyl alcohol substrate of the method has a wide range of applications, convenient reaction operation, mild reaction conditions, simple post-processing, high raw material conversion rate, short reaction cycle, high product purity, is conducive to industrial production, and has high atomic utilization, which is in line with the concept of modern green industrialization. DETAILED DESCRIPTION
[0049] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0050] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.
[0051] Unless otherwise specified, conventional methods were used for testing and instrument settings were those recommended by the manufacturer.
[0052] Preparation Example 1 Preparation of Copper / Nickel Bimetallic Supported Catalyst
[0053] Weigh 5.3 g of copper nitrate and 2.3 g of nickel acetate, add them to 12 mL of water to prepare a mixed solution, immerse the carrier alumina (size 0.8 mm) in the mixed solution for impregnation (immersion at 25 ° C for 12 h), then wash and dry, calcine at 350 ° C in an air atmosphere for 6 h, and then heat at 400 ° C in a hydrogen atmosphere for 12 h to reduce to obtain a copper / nickel bimetallic supported catalyst.
[0054] Example 1
[0055] (1) Methanol (64 g, 2 mol) and catalyst I (sodium tert-butoxide (100 mg) and potassium carbonate (100 mg)) were added into a 250 mL three-necked flask at once, stirred to dissolve, and the temperature in the reaction flask was lowered to 0°C using a hot and cold integrated machine. Then, acrylonitrile (53 g, 1 mol) was added dropwise using a constant pressure funnel. After the addition was completed, the temperature was naturally raised to room temperature and reacted for 5 hours to obtain a methanol solution of 3-methoxypropionitrile (acrylonitrile conversion rate>99%).
[0056] (2) Catalyst II (copper / nickel bimetallic supported catalyst prepared in Preparation Example 1) was filled in the Oushisheng high-pressure hydrogenation reactor, and the fixed bed reaction temperature was set to 80°C, the hydrogen pressure was set to 4 MPa, the hydrogen flow rate was set to 40 mL / min, and the NH 3 The flow rate was 0.2 mL / min, and the reaction liquid feed space velocity was 1 h -1 The methanol solution of all 3-methoxypropionitrile prepared in step (1) is continuously fed into a fixed bed for reaction, so that the addition product can be completely hydrogenated and converted, and the target product 3-methoxypropylamine (85.6 g) can be obtained by separation and purification. The structure of the target product is shown in Table 1. The overall yield of the process is 96%.
[0057] Example 2
[0058] (1) Ethanol (92 g, 2 mol) and catalyst I (sodium tert-butoxide (100 mg) and potassium carbonate (100 mg)) were added to a 250 mL three-necked flask at once, stirred to dissolve, and the temperature in the reaction flask was lowered to 0°C using a hot and cold integrated machine. Then, acrylonitrile (53 g, 1 mol) was added dropwise using a constant pressure funnel. After the addition was completed, the temperature was naturally raised to room temperature and reacted for 5 hours to obtain an ethanol solution of 3-ethoxypropionitrile (acrylonitrile conversion rate>99%).
[0059] (2) Catalyst II (copper / nickel bimetallic supported catalyst in Preparation Example 1) was filled in the Oushisheng high-pressure hydrogenation reactor, and the fixed bed reaction temperature was set to 80°C, the hydrogen pressure was set to 4 MPa, the hydrogen flow rate was set to 40 mL / min, and the NH 3 The flow rate was 0.2 mL / min, and the reaction liquid feed space velocity was 1 h -1 The ethanol solution of all 3-ethoxypropionitrile prepared in step (1) is continuously fed into a fixed bed for reaction, so that the addition product can be completely hydrogenated and converted, and the target product 3-ethoxypropylamine (97 g) can be obtained by separation and purification. The structure of the target product is shown in Table 1. The overall yield of the process is 94%.
[0060] Example 3
[0061] (1) Isopropanol (120 g, 2 mol) and catalyst I (sodium tert-butoxide (100 mg) and potassium carbonate (100 mg)) were added to a 250 mL three-necked flask at once, stirred to dissolve, and the temperature in the reaction flask was lowered to 0°C using a hot and cold integrated machine. Then, acrylonitrile (53 g, 1 mol) was added dropwise using a constant pressure funnel. After the addition was completed, the temperature was naturally raised to room temperature and reacted for 10 hours to obtain an isopropanol solution of 3-isopropoxypropionitrile (acrylonitrile conversion rate>98%).
[0062] (2) Catalyst II (copper / nickel bimetallic supported catalyst in Preparation Example 1) was filled in the Oushisheng high-pressure hydrogenation reactor, and the fixed bed reaction temperature was set to 90°C, the hydrogen pressure was set to 4 MPa, the hydrogen flow rate was set to 40 mL / min, and the NH 3 The flow rate was 0.2 mL / min and the reaction liquid feed space velocity was 0.5 h -1 The isopropanol solution of all 3-isopropoxypropionitrile prepared in step (1) is continuously fed into a fixed bed for reaction, so that the addition product can be completely hydrogenated and converted, and the target product 3-isopropoxypropylamine (110.2 g) can be obtained by separation and purification. The structure of the target product is shown in Table 1. The overall yield of the process is 94%.
[0063] Table 1 Structure of target product
[0064]
[0065] Example 4
[0066] Under the same conditions as in Example 1, a methanol solution of 3-methoxypropionitrile was continuously introduced in step (2) to carry out a cyanide hydrogenation test of methoxypropionitrile. The results showed that the catalyst had a stable life of >250 h, with a conversion rate of methoxypropionitrile >99% and a selectivity of methoxypropylamine >98%.
[0067] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A green synthesis method of alkoxypropylamine, characterized in that: The steps include: S1, subjecting a raw material liquid containing an alkyl alcohol, acrylonitrile, and a composite organic base catalyst to a Michael addition reaction to obtain a reaction liquid containing an alkoxypropionitrile; S2. In a mixed atmosphere of hydrogen and alkaline auxiliary agent, the reaction solution obtained in step S1 is continuously contacted with a copper / nickel bimetallic supported catalyst to carry out a hydrogenation reaction to obtain the alkoxypropylamine.
2. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S1, the composite organic base catalyst includes an organic base and an inorganic base; The organic base is selected from at least one of sodium tert-butoxide, potassium tert-butoxide and lithium tert-butoxide; The inorganic base is selected from at least one of potassium carbonate, cesium carbonate, sodium hydroxide and potassium hydroxide; Preferably, the weight ratio of the organic base to the inorganic base is 1:0.6-1.
3.
3. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S2, the copper / nickel bimetallic supported catalyst includes an active component and a carrier; The active component is loaded on the carrier; The active components include active component I and active component II; The active component I comprises metallic nickel, and the loading amount of the metallic nickel in the copper / nickel bimetallic supported catalyst is 4-7 wt%; The active component II includes metallic copper, and the loading amount of the metallic copper in the copper / nickel bimetallic supported catalyst is 10-15 wt%.
4. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S2, the continuous contact conditions include: the mass space velocity of the reaction liquid is 0.5 to 1.5 h -1 .
5. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S2, the conditions of the hydrogenation reaction include: a reaction temperature of 70 to 200°C, and a reaction pressure of 3 to 7 MPa in terms of hydrogen partial pressure.
6. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S2, the alkaline auxiliary agent is selected from at least one of NH3, triethylamine, and diisopropylethylamine; Preferably, in step S2, the molar ratio of the alkoxypropionitrile to the alkaline auxiliary agent in the reaction solution is 1:10-20.
7. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S1, the weight ratio of acrylonitrile to the composite organic base catalyst is 1:0.001-0.
005.
8. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: The alkyl alcohol is independently selected from at least one of methanol, ethanol, propanol, isopropanol, butanol, etc.; Preferably, in step S1, the molar ratio of the alkyl alcohol to acrylonitrile is 2 to 5:
1.
9. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S1, the conditions of the Michael addition reaction include: reaction temperature of -10 to 30°C, and reaction time of 2 to 10 hours.
10. The green synthesis method of alkoxypropylamine according to claim 1, characterized in that: In step S1, the raw material solution is prepared by the following method: The temperature of the mixed solution containing the alkyl alcohol and the composite organic base catalyst is lowered to -10 to 10°C, and then acrylonitrile is added dropwise to the mixed solution, and the temperature is naturally raised to room temperature after the addition is completed, to obtain the raw material solution; Preferably, the dropping speed is 3 to 10 mL / min.