A process for the hydrocyanation of an olefinic compound

Abstract

The application provides a hydrocyanation reaction method, which is carried out in a reaction system containing an aromatic amine under the action of a nickel-monodentate phosphite ligand catalyst, and the structure of the aromatic amine is: wherein, X 1 - X 3 groups and Y 1 - Y 3 groups each include any one of hydrogen, an alkyl group, an alkoxy group, an alkylamine group, a hydroxyl group and an amino group. The hydrocyanation reaction method of the application includes the nickel-monodentate phosphite ligand catalyst and the aromatic amine with a specific structure, so that the hydrocyanation reaction method can be catalyzed to be shortened in time, the accumulation of ligand hydrolysis products can be significantly reduced or eliminated, and the catalyst loss in the reaction can be reduced. The hydrocyanation reaction method of the application has high reaction efficiency, stable catalyst performance, high raw material conversion rate and high product selectivity, and can be used for the preparation process of preparing adiponitrile by directly hydrocyanating a large amount of butadiene.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, and specifically to a method for hydrocyanation reaction. Background Technology

[0002] Adiponitrile (ADN) is an important raw material intermediate for the production of Nylon 66 and a crucial link in the nylon and specialty polyurethane industry chain. Among the various production methods of adiponitrile, the direct hydrocyanation of butadiene is the mainstream process, accounting for the largest share of global production capacity.

[0003] The process route for producing adiponitrile from butadiene via direct hydrocyanation is as follows:

[0004]

[0005] The specific reaction steps include: a first-step hydrocyanation, in which butadiene undergoes addition with hydrogen cyanide (HCN) in the presence of a nickel catalyst to generate 2-methyl-3-butenonitrile (2M3BN) and 3-pentenonitrile (3PN); 2M3BN isomerization, in which 2M3BN undergoes an isomerization reaction to convert to 3PN in the presence of a nickel catalyst; a second-step hydrocyanation, in which 3PN isomerizes to 4-pentenonitrile (4PN), which then adds with HCN to generate ADN and the byproduct 2-methylglutaronitrile (MGN). This step requires a nickel catalyst and a Lewis acid promoter, and has high requirements for catalyst activity, making it the key step in the entire reaction.

[0006] The direct hydrocyanation method for butadiene involves a two-step hydrocyanation process. Taking the one-step hydrocyanation reaction as an example, the specific hydrocyanation reaction process is as follows:

[0007]

[0008] In this process, the zero-valent nickel-phosphorus catalyst [NiL4] (where L is a ligand) loses one ligand molecule to form [NiL3], which then combines with HCN to generate [HNiL3CN]. It further loses one ligand molecule to generate [HNiL2CN], which then combines with butadiene to form the intermediate [C4H6-HNiL2CN]. This intermediate can react along two pathways to generate two different substances, 3PN and 2M3BN, respectively, and then regenerate [NiL3] to continue participating in the catalytic cycle reaction.

[0009] However, in actual production, the hydrocyanation reaction faces many challenges: First, the presence of water in the reaction system may cause hydrolysis of the phosphite ligands of the nickel catalyst, producing acidic hydrolysis products, which further accelerate ligand hydrolysis and gradually deactivate the nickel-monodentate phosphite ligand catalyst. Second, when the HCN concentration in the reaction system is high, it will attack the active nickel ([NiL3] and [NiL2], etc.) in the hydrocyanation reaction, generating nickel cyanide (Ni(CN)2) precipitate, causing catalyst deactivation. Third, the hydrocyanation reaction (especially the two-step hydrocyanation reaction) has a slow rate and long residence time, resulting in a high amount of catalyst deactivation. Therefore, developing a hydrocyanation reaction process with high reaction efficiency, high stability, and effective avoidance of catalyst deactivation is an urgent technical problem to be solved. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention discloses a hydrocyanation reaction method that can not only shorten the reaction time, but also significantly reduce or eliminate the accumulation of ligand hydrolysis products, reduce the amount of nickel cyanide precipitate, and stabilize the catalyst.

[0011] To achieve the above technical objectives, this invention proposes a hydrocyanation reaction method, wherein the hydrocyanation reaction is carried out in a reaction system containing an aromatic amine under the action of a nickel-monodentate phosphite ligand catalyst, wherein the aromatic amine has the following structure:

[0012]

[0013] Among them, X 1 -X 3 Group and Y 1 -Y 3 The groups include any one of hydrogen, alkyl, alkoxy, alkylamine, hydroxy, and amino groups.

[0014] As mentioned earlier, during the hydrocyanation reaction, the active nickel intermediates (such as [NiL3] and [NiL2]) are exposed due to the partial loss of ligands, making them susceptible to attack by polar molecules such as hydrocyanic acid and water, resulting in the formation of nickel cyanide and hydrolysis products, thus causing catalyst loss. In the above technical solution, the included aromatic amines with specific structures are compounds with strong complexing interactions with nickel. They can coordinate with the active nickel intermediates in a timely manner during the hydrogenation reaction, thereby protecting the active nickel intermediates and reducing catalyst loss. Simultaneously, the aromatic amine compounds can form a hydrophobic environment around the active nickel intermediates, further reducing the possibility of catalyst hydrolysis and inhibiting the formation of hydrolysis products. Furthermore, the improved stability of the active nickel intermediates effectively increases the overall hydrogenation reaction rate.

[0015] The embodiments of the present invention demonstrate the effects of a hydrocyanation reaction method comprising a nickel-monodentate phosphite ligand catalyst and an aromatic amine.

[0016] In a further example of the invention, for X 1 -X 3 Group and Y 1 -Y 3 The structure of the group has been optimized. Optionally, the alkyl group has the structural formula -R, and the alkoxy group has the structural formula [missing information]. The structural formula of the alkylamine group is: The R group includes any one of methyl, ethyl, isopropyl, and tert-butyl.

[0017] In some alternative examples of the present invention, the aromatic amine may be selected from any of those in Table 1.

[0018] Table 1

[0019] Serial Number <![CDATA[X 1 ]]> <![CDATA[X 2 ]]> <![CDATA[X 3 ]]> <![CDATA[Y 1 ]]> <![CDATA[Y 2 ]]> <![CDATA[Y 3 ]]> Aromatic amine A1 hydrogen methoxy hydrogen hydrogen methoxy hydrogen Aromatic amine A2 methyl methyl methyl methyl methyl methyl Aromatic amine A3 methyl methoxy methyl methyl methoxy methyl Aromatic amine A4 Isopropyl methoxy Isopropyl Isopropyl methoxy Isopropyl Aromatic amine A5 Isopropyl tert-butyl Isopropyl Isopropyl tert-butyl Isopropyl Aromatic amine A6 methyl tert-butyl methyl methyl tert-butyl methyl Aromatic amine A7 hydrogen tert-butyl hydrogen hydrogen tert-butyl hydrogen Aromatic amine A8 methyl methoxy tert-butyl methyl methoxy tert-butyl Aromatic amine A9 methyl Dimethylamino methyl methyl Dimethylamino methyl Aromatic amine A10 hydrogen Dimethylamino hydrogen hydrogen Dimethylamino hydrogen Aromatic amine A11 methyl Diethylamino methyl methyl Diethylamino methyl Aromatic amine A12 methyl Diisopropylamino Isopropyl methyl Diisopropylamino Isopropyl

[0020] In a further example of the invention, the structure of the ligand comprising the nickel-monodentate phosphite ligand catalyst was optimized. Optionally, the structure of the monodentate phosphite ligand is as follows:

[0021]

[0022] Among them, R 1 R 2 and R 3 The groups include any one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, and methoxy.

[0023] In a further example of the present invention, the ratio of the nickel-monodentate phosphite ligand catalyst to the aromatic amine in the hydrocyanation reaction method was explored and optimized. Optionally, the mass ratio of the nickel-monodentate phosphite ligand catalyst to the aromatic amine is 1:(0.05-0.8), and more preferably 1:(0.1-0.6), which is beneficial for the effective coordination of the aromatic amine with the active nickel intermediate during the hydrocyanation reaction process and improves the stability of the catalyst.

[0024] In a further example of the present invention, the hydrocyanation reaction method is a hydrocyanation reaction method for preparing adiponitrile.

[0025] Furthermore, the hydrocyanation reaction method includes a one-step hydrocyanation reaction method for preparing pentenonitrile from butadiene.

[0026] Furthermore, the reaction temperature of the one-step hydrocyanation reaction method is 40-110℃, preferably 50-95℃. This temperature range is relatively mild, easy to control, and has strong process operability.

[0027] It should be noted that the pressure for the one-step hydrocyanation reaction method in this invention is not limited and can be selected as 1-5 bar.

[0028] Furthermore, the reaction time of the one-step hydrocyanation reaction method is 1-5 hours. As can be seen from the analysis of the examples and comparative examples, the technical solution of the present invention can significantly improve the reaction rate, shorten the reaction time, and improve the overall process production efficiency.

[0029] Furthermore, when the hydrocyanation reaction method is a one-step hydrocyanation reaction method, the X in the structure of the aromatic amine... 1 X 3 Y 1 Y 3 The groups are selected from hydrogen or alkyl groups, X 2 Y 2 The groups are selected from alkyl or alkoxy groups, respectively.

[0030] Furthermore, in the one-step hydrocyanation reaction method, the mass ratio of nickel-monodentate phosphite ligand catalyst to butadiene is (0.5-3):1000, preferably (0.75-2.5):1000. By adding trace amounts of specific aromatic amine substances, the present invention can significantly improve the stability of the catalyst and increase the reaction rate during the one-step hydrocyanation reaction method. After the reaction is completed, the aromatic amine can be separated and high-purity pentene nitrile product can be obtained by separation and purification processes, such as extraction, distillation or extractive distillation.

[0031] Furthermore, the hydrocyanation reaction method also includes a two-step hydrocyanation reaction method for preparing adiponitrile from pentenonitrile.

[0032] Furthermore, the reaction temperature of the two-step hydrocyanation reaction method is 35-90℃, preferably 40-80℃. This temperature range is relatively mild, easy to control, and the overall process is highly operable.

[0033] It should be noted that the pressure for the two-step hydrocyanation reaction method in this invention is not limited and can be selected as 1-5 bar.

[0034] Furthermore, the reaction time of the one-step hydrocyanation reaction method is 1-10 hours. As can be seen from the analysis of the examples and comparative examples, the technical solution of the present invention can significantly improve the reaction rate, shorten the reaction time, and improve the overall process production efficiency.

[0035] Furthermore, in the two-step hydrocyanation reaction method, the X in the structure of the aromatic amine... 1 X 3 Y 1 Y 3 The groups are selected from any one of hydrogen, alkyl, or alkoxy, X 2 Y 2 The groups are selected from alkoxy or alkylamine groups, respectively.

[0036] Furthermore, in the two-step hydrocyanation reaction method, the mass ratio of the nickel-monodentate phosphite ligand catalyst to the adiponitrile is (0.5-3):1000, preferably (0.75-2.5):1000. This invention significantly improves the catalyst stability and reaction rate during the one-step hydrocyanation reaction by adding trace amounts of a specific aromatic amine. After the reaction is complete, the aromatic amine can be separated through separation and purification processes, such as extraction, distillation, or extractive distillation, to obtain a high-purity adiponitrile product.

[0037] Furthermore, the two-step hydrocyanation reaction method is carried out with the participation of a co-catalyst, the addition of which is beneficial to synergistically improving the stability of the catalyst and the reaction rate; the co-catalyst includes one of zinc chloride, aluminum chloride, ferric chloride, titanium tetrachloride, and triphenylboron.

[0038] Furthermore, the mass ratio of the nickel-monodentate phosphite ligand catalyst to the co-catalyst is (0.2-0.8):1, preferably (0.3-0.7):1. By optimizing the amount of catalyst and co-catalyst, the reaction rate can be improved synergistically with the aromatic amine, the occurrence of side reactions can be reduced, and the reaction efficiency can be improved.

[0039] Compared with existing technologies, the beneficial effects of this invention are as follows: The hydrocyanation reaction method of this invention includes a nickel-monodentate phosphite ligand catalyst and an aromatic amine with a specific structure, which not only shortens the hydrocyanation reaction time but also significantly reduces or eliminates the accumulation of ligand hydrolysis products and reduces catalyst loss during the reaction. The hydrocyanation reaction method of this invention has high reaction efficiency, stable catalyst performance, and high feed conversion rate and product selectivity, and can be used in the preparation process of adiponitrile via direct hydrocyanation of butadiene in large quantities. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more comprehensive description will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the invention in any way, i.e., not intended to limit the scope of protection of the invention.

[0041] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which this invention pertains. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0042] It should be noted that in the nickel-monodentate phosphite ligand catalyst described in this invention, the coordination number of nickel is 4 or 6, generally 4. This invention aims to solve the technical problem of catalyst instability in the hydrocyanation reaction process in the prior art. Therefore, the embodiment section of this application will not further explain the ratio of each nickel to the number of monodentate phosphite ligands.

[0043] In this embodiment of the invention, the conversion rate of the hydrocyanation reaction method is calculated using the percentage of peak area in gas chromatography. For example: the conversion rate of the one-step hydrocyanation reaction method = (2M3BN+3PN) / (2M3BN+3PN+butadiene)×100%, and the selectivity of 3PN = 3PN / (2M3BN+3PN)×100%; the conversion rate of the two-step hydrocyanation reaction method = (ADN+MGN) / (ADN+MGN+3PN)×100%, and the selectivity of ADN = ADN / (ADN+MGN)×100%; the content of the catalyst in the reaction system can be characterized by the Ni content in the supernatant.

[0044] Example 1

[0045] A one-step hydrocyanation reaction method, which uses butadiene as a starting material to prepare pentenenitrile in a reaction system containing aromatic amines and in the presence of a nickel-monodentate phosphite ligand catalyst, specifically:

[0046] (1) Material preparation: The catalyst used in this embodiment is a nickel-tris(2-ethylphenyl) phosphite catalyst, which can be prepared by the following steps: ① Synthesis of tris(2-ethylphenyl) phosphite ligand: Under a nitrogen atmosphere, 2-ethylphenol (73.2 g, 0.6 mol) is added to a 250 mL round-bottom flask, and phosphorus trichloride (27.4 g, 0.2 mol) is added dropwise at room temperature. A large amount of HCl byproduct is generated during the reaction, which is absorbed by alkaline solution. After the addition is completed, the mixture is stirred at room temperature for 1 h, and then slowly heated to 150 °C until no more HCl escapes. The reactants are then purified by high-vacuum distillation to obtain a purity of over 90%. 9% of the product, yield 98%; the product was characterized by 31N PMR and mass spectrometry, confirming that the target structure was tris(2-ethylphenyl) phosphite; ② Synthesis of nickel-tris(2-ethylphenyl) phosphite catalyst: Tris(2-ethylphenyl) phosphite, nickel powder and 3-pentenonitrile were added to a round-bottom flask equipped with a mechanical stirrer, and the mixture was stirred continuously at about 110°C for about 24 h under a nitrogen atmosphere; after the reaction was completed, the unreacted nickel powder in the reaction material was removed by filtration under a nitrogen atmosphere, and the nickel-tris(2-ethylphenyl) phosphite catalyst containing 79% tris(2-ethylphenyl) phosphite, 19% pentenonitrile and 2% nickel was obtained.

[0047] It should be noted that the nickel powder mentioned in the embodiments of the invention is commercially available nickel powder. Furthermore, the preparation processes of the ligands and the nickel-monodentate phosphite ligand catalysts in the embodiments of the invention are merely preferred demonstrations. Those skilled in the art can prepare the ligands or nickel-monodentate phosphite ligand catalysts through other methods without inventive effort. In certain operating conditions, suitable types of ligands or nickel-monodentate phosphite ligand catalysts can be directly purchased based on the technical solutions of the present invention. This does not limit the scope of protection of the present invention.

[0048] (2) One-step hydrocyanation reaction method: Nickel-tris(2-ethylphenyl) phosphite catalyst (1.5 mmol), aromatic amine A1 (0.9 mmol) and butadiene (2.0 mol) were placed in a stainless steel reactor. After purging with nitrogen, the reaction system was heated to 50°C. Then, hydrogen cyanide (1.9 mol) was slowly added to the reactor by a pump for 2 hours. After the addition was completed, the reaction was continued at 50°C. As the reaction proceeded, samples were taken from the reactor at different times and analyzed. The results are shown in Table 2.

[0049] Table 2

[0050] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 54.65 29.95 15.40 339 45.35 66.04 2 44.25 37.05 18.70 334 55.75 66.46 3 34.75 43.36 21.89 329 65.25 66.45 4 25.05 49.56 25.39 330 74.95 66.12 5 14.45 56.67 28.88 328 85.55 66.24

[0051] Example 2

[0052] A one-step hydrocyanation reaction method, which uses butadiene as a starting material to prepare pentenenitrile in a reaction system containing aromatic amines and in the presence of a nickel-monodentate phosphite ligand catalyst, specifically:

[0053] (1) Material preparation: The catalyst used in this embodiment is a nickel-tris(2-isopropyl-4-methoxyphenyl) phosphite catalyst, which is prepared by coordinating and complexing commercially available tris(2-isopropyl-4-methoxyphenyl) phosphite with nickel powder: Tris(2-isopropyl-4-methoxyphenyl) phosphite, nickel powder and 3-pentenonitrile are added to a round-bottom flask equipped with a mechanical stirrer and stirred continuously for about 24 hours at about 120°C under a nitrogen atmosphere; after the reaction is completed, the unreacted nickel powder in the reaction material is removed by filtration under a nitrogen atmosphere to obtain the nickel-tris(2-isopropyl-4-methoxyphenyl) phosphite catalyst containing 81% tris(2-isopropyl-4-methoxyphenyl) phosphite, 17% pentenonitrile and 2% nickel.

[0054] (2) One-step hydrocyanation reaction method: Nickel-tris(2-isopropyl-4-methoxyphenyl) ester catalyst (2.5 mmol), aromatic amine A3 (0.25 mmol) and butadiene (1.0 mol) were placed in a stainless steel reactor. After purging with nitrogen, the reaction system was heated to 95°C. Then, hydrogen cyanide (0.95 mol) was slowly added to the reactor by a pump for 2 hours. After the addition was completed, the reaction was continued at 95°C. As the reaction proceeded, samples were taken from the reactor at different times and analyzed. The results are shown in Table 3.

[0055] Table 3

[0056] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 56.15 29.65 14.20 324 43.85 67.62 2 45.53 36.65 17.82 330 54.47 67.28 3 35.25 43.36 21.39 319 64.75 66.97 4 26.25 49.56 24.19 325 73.75 67.20 5 15.56 56.67 27.77 327 84.44 67.11

[0057] Example 3

[0058] Based on the one-step hydrocyanation reaction method shown in Example 1, the catalyst, raw materials and control parameters used in this example are the same as those in Example 1. The difference is that the aromatic amine added in the one-step hydrocyanation reaction method of this example is aromatic amine A9. The reaction results are shown in Table 4 by taking samples of the reaction system at different times for analysis.

[0059] Table 4

[0060] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 65.25 23.24 11.51 338 34.75 66.88 2 55.16 30.01 14.83 330 44.84 66.93 3 44.37 37.19 18.44 323 55.63 66.85 4 36.09 43.03 20.88 316 63.91 67.33 5 25.01 50.65 24.34 305 74.99 67.54

[0061] Combining Tables 2 and 4, the one-step hydrocyanation reaction method containing A1 aromatic amines is relatively better than the hydrocyanation reaction method containing A9 aromatic amines. In the actual reaction process, a suitable aromatic amine can be selected according to the specific working conditions to catalyze the one-step hydrocyanation reaction method.

[0062] Example 4

[0063] A two-step hydrocyanation reaction method, which uses pentyrenonitrile as a starting material to prepare adiponitrile in a reaction system containing aromatic amines under the action of a nickel-monodentate phosphite ligand catalyst, specifically:

[0064] In this embodiment, the nickel-tris(2-ethylphenyl) phosphite catalyst shown in Example 1 was used. The catalyst (5 mmol), anhydrous zinc chloride (16 mmol), aromatic amine A9 (0.5 mmol), and 3PN (2.0 mol) were placed in a stainless steel reactor. After purging with nitrogen, the reaction system was heated to 40°C. Then, hydrogen cyanide (1.9 mol) was slowly added to the reactor using a pump over a period of 2 hours. After the addition was completed, the reaction was continued at 40°C. As the reaction proceeded, samples were collected from the reactor at different times and analyzed. The results are shown in Table 5.

[0065] Table 5

[0066] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 75.90 19.81 4.29 340 24.10 82.20 4 63.02 30.45 6.53 336 36.98 82.34 6 51.98 39.55 8.47 330 48.02 82.36 8 38.87 50.24 10.89 327 61.13 82.19 10 26.65 60.42 12.93 324 73.35 82.37

[0067] Example 5

[0068] A two-step hydrocyanation reaction method, which uses pentyrenonitrile as a starting material to prepare adiponitrile in a reaction system containing aromatic amines under the action of a nickel-monodentate phosphite ligand catalyst, specifically:

[0069] This embodiment uses the nickel-tris(2-isopropyl-4-methoxyphenyl) ester catalyst shown in Example 2. The catalyst (0.6 mmol), anhydrous titanium tetrachloride (0.9 mmol), aromatic amine A11 (0.36 mmol), and 3PN (0.8 mol) are placed in a stainless steel reactor. After purging with nitrogen, the reaction system is heated to 80°C. Then, hydrogen cyanide (0.76 mol) is slowly added to the reactor using a pump, and the addition time is 2 hours. After the addition is completed, the reaction continues at 80°C. As the reaction proceeds, samples are taken from the reactor at different times and analyzed. The results are shown in Table 6.

[0070] Table 6

[0071] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 74.90 20.65 4.45 340 25.10 82.27 4 62.03 31.14 6.83 335 37.97 82.01 6 50.01 41.06 8.93 332 49.99 82.14 8 34.65 53.74 11.61 329 65.35 82.23 10 22.34 63.34 14.32 326 77.66 81.56

[0072] Example 6

[0073] Based on the two-step hydrocyanation reaction method shown in Example 4, the catalyst, raw materials and control parameters used in this example are the same as those in Example 4. The difference is that the aromatic amine added in the two-step hydrocyanation reaction method of this example is aromatic amine A1. The reaction results are shown in Table 7 by taking samples of the reaction system at different times for analysis.

[0074] Table 7

[0075] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 80.60 15.91 3.49 340 19.40 82.01 4 68.23 26.21 5.56 322 31.77 82.50 6 56.01 35.91 8.08 313 43.99 81.63 8 43.25 46.65 10.10 302 56.75 82.20 10 31.22 56.89 11.89 292 68.78 82.71

[0076] Combining Tables 5 and 7, the two-step hydrocyanation reaction method containing A9 aromatic amines is relatively better than the hydrocyanation reaction method containing A1 aromatic amines. In the actual reaction process, a suitable aromatic amine can be selected according to the specific working conditions to catalyze the two-step hydrocyanation reaction method.

[0077] Comparative Example 1

[0078] Based on the one-step hydrocyanation reaction method shown in Example 1, the catalyst, raw materials and control parameters used in this comparative example are the same as those in Example 1. The difference is that no aromatic amine is added in the one-step hydrocyanation reaction method of this comparative example. The reaction results are shown in Table 8 by taking samples of the reaction system at different times for analysis.

[0079] Table 8

[0080] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 84.65 10.23 5.12 338 15.35 66.64 2 71.25 19.45 9.30 315 28.75 67.65 3 58.35 27.65 14.00 285 41.65 66.39 4 49.15 34.13 16.72 254 50.85 67.12 5 37.25 41.56 21.19 229 62.75 66.23

[0081] Based on Tables 2 and 8, it can be confirmed that after the same reaction time, the reaction system of Example 1, which added aromatic amine A1 to the one-step hydrocyanation reaction system, had a higher feed conversion rate and a higher Ni content in the supernatant. When the reaction time reached 5 hours, the Ni content in the supernatant of the reaction system of Comparative Example 1, which did not use aromatic amine, decreased to 68% of the original value, and the butadiene conversion rate was 62.75%, while the Ni content in the supernatant of the reaction system of Example 1 remained at 97% of the original value, and the butadiene conversion rate reached 85.55%. This verifies that the present invention, which includes a nickel-monodentate phosphite ligand catalyst and a specific structured aromatic amine, can significantly improve the reaction rate of the one-step hydrocyanation reaction method and reduce catalyst loss.

[0082] Comparative Example 2

[0083] Based on the two-step hydrocyanation reaction method shown in Example 4, the catalyst, raw materials and control parameters used in this comparative example are the same as those in Example 4. The difference is that no aromatic amine is added in the two-step hydrocyanation reaction method of this comparative example. The reaction results are shown in Table 9 by taking samples of the reaction system at different times for analysis.

[0084] Table 9

[0085] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 85.60 11.81 2.59 340 14.40 82.01 4 73.24 22.12 4.64 312 26.76 82.66 6 61.98 31.25 6.77 281 38.02 82.19 8 49.15 41.89 8.96 252 50.85 82.38 10 37.75 51.32 10.93 224 62.25 82.44

[0086] A comparison of Tables 5 and 9 confirms that, after the same reaction time, the reaction system of Example 3, which incorporates aromatic amine A9 in the two-step hydrocyanation reaction method, exhibits a higher 3PN conversion rate and a higher Ni content in the supernatant. When the reaction time reaches 10 hours, the Ni content in the supernatant of the reaction system of Comparative Example 3, which does not use aromatic amine, decreases to 66% of its original value, and the butadiene conversion rate reaches 62.25%. In contrast, the Ni content in the supernatant of the reaction system of Example 3 remains at 95% of its original value, and the butadiene conversion rate reaches 73.35%. This verifies that the nickel-monodentate phosphite ligand catalyst and the specifically structured aromatic amine of this invention can significantly improve the reaction rate of the two-step hydrocyanation reaction method while reducing catalyst loss.

[0087] Comparative Example 3

[0088] A two-step hydrocyanation reaction method is disclosed, which prepares adiponitrile from pentenonitrile. In this comparative example, the nickel-tris(2-ethylphenyl) phosphite catalyst shown in Example 1 is used. Specifically, the catalyst (5 mmol), anhydrous zinc chloride (16 mmol), and 3PN (2.0 mol) are placed in a stainless steel reactor, and an aromatic amine containing one aromatic ring is added:

[0089]

[0090] The relevant parameters and control conditions of this comparative example are the same as those of Example 4; the reaction system was sampled and analyzed at different times, and the results are shown in Table 10.

[0091] Table 10

[0092] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 81.36 15.33 3.31 340 18.64 82.24 4 69.45 25.11 5.44 325 30.55 82.19 6 57.13 35.21 7.66 317 42.87 82.13 8 44.35 45.72 9.93 309 55.65 82.16 10 33.25 54.98 11.77 295 66.75 82.37

[0093] Comparative Example 4

[0094] A two-step hydrocyanation reaction method is disclosed, which prepares adiponitrile from pentyrenonitrile. In this comparative example, the nickel-tris(2-ethylphenyl) phosphite catalyst shown in Example 1 is used. Specifically, the catalyst (5 mmol), anhydrous zinc chloride (16 mmol), and 3PN (2.0 mol) are placed in a stainless steel reactor, and an aromatic amine containing three aromatic rings is added:

[0095]

[0096] The relevant parameters and control conditions of this comparative example are the same as those of Example 4; the reaction system was sampled and analyzed at different times, and the results are shown in Table 11.

[0097] Table 11

[0098] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 79.59 16.87 3.54 340 20.41 82.66 4 69.23 25.31 5.46 328 30.77 82.26 6 57.24 35.09 7.67 319 42.76 82.06 8 45.06 45.35 9.59 318 54.94 82.54 10 34.15 54.18 11.67 301 65.85 82.28

[0099] As verified by combining Tables 5, 10, and 11, the hydrocyanation reaction method of this invention, which incorporates aromatic amines with a specific structure containing two aromatic rings, exhibits superior conversion rates and catalyst stability compared to hydrocyanation reactions catalyzed by aromatic amines containing one or three aromatic rings. It is speculated that the aromatic amines with a specific structure containing two aromatic rings in this invention provide suitable steric hindrance, promoting enhanced catalytic activity. Simultaneously, the electron-donating groups in the aromatic amines included in this invention's hydrocyanation reaction method exhibit a more pronounced electronic effect, enhancing the complexation of the N atom with the active nickel intermediate and strengthening the catalyst's protective effect. Through the synergistic optimization of steric hindrance and electronic effects, the conversion rate, product selectivity, and catalyst stability of this invention's hydrocyanation reaction method are improved.

[0100] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions; the dimensional data in this embodiment do not limit the technical solution, but merely illustrate one specific working condition. For those skilled in the art, various simple improvements and modifications can be made without departing from the concept of the present invention, and all such improvements and modifications should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for hydrocyanation reaction, characterized in that, The hydrocyanation reaction is carried out in a reaction system containing an aromatic amine, under the action of a nickel-monodentate phosphite ligand catalyst, wherein the aromatic amine has the following structure: Among them, X 1 -X 3 Group and Y 1 -Y 3 The groups are any one of hydrogen, alkyl, alkoxy, alkylamine, hydroxy, and amino; the alkyl group has the structural formula -R, and the alkoxy group has the structural formula [missing information]. The structural formula of the alkylamine group is: Wherein, the R group is any one of methyl, ethyl, isopropyl, and tert-butyl.

2. The hydrocyanation reaction method according to claim 1, characterized in that, The structure of the monodentate phosphite ligand is as follows: Among them, R 1 R 2 and R 3 The groups are any one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, and methoxy.

3. The hydrocyanation reaction method according to claim 1, characterized in that, The mass ratio of the nickel-monodentate phosphite ligand catalyst to the aromatic amine is 1:(0.05-0.8).

4. The hydrocyanation reaction method according to claim 3, characterized in that, The mass ratio of the nickel-monodentate phosphite ligand catalyst to the aromatic amine is 1:(0.1-0.6).

5. The hydrocyanation reaction method according to any one of claims 1 to 4, characterized in that, The hydrocyanation reaction method is a hydrocyanation reaction method for preparing adiponitrile.

6. The hydrocyanation reaction method according to claim 5, characterized in that, The hydrocyanation reaction method is a one-step hydrocyanation reaction method for preparing pentenonitrile from butadiene.

7. The hydrocyanation reaction method according to claim 6, characterized in that, The reaction temperature of the one-step hydrocyanation reaction method is 40-110℃.

8. The hydrocyanation reaction method according to claim 7, characterized in that, The reaction temperature of the one-step hydrocyanation reaction method is 50-95℃.

9. The hydrocyanation reaction method according to claim 6, characterized in that, In the one-step hydrocyanation reaction method, X in the structure of the aromatic amine 1 X 3 Y 1 Y 3 The groups are selected from hydrogen or alkyl groups, X 2 Y 2 The groups are selected from alkyl or alkoxy groups, respectively; And / or, in the one-step hydrocyanation reaction method, the mass ratio of nickel-monodentate phosphite ligand catalyst to butadiene is (0.5-3):1000.

10. The hydrocyanation reaction method according to claim 9, characterized in that, In the one-step hydrocyanation reaction method, the mass ratio of nickel-monodentate phosphite ligand catalyst to butadiene is (0.75-2.5):1000.

11. The hydrocyanation reaction method according to claim 5, characterized in that, The hydrocyanation reaction method is a two-step hydrocyanation reaction method for preparing adiponitrile from pentenenitrile.

12. The hydrocyanation reaction method according to claim 11, characterized in that, The reaction temperature of the two-step hydrocyanation reaction method is 35-90℃.

13. The hydrocyanation reaction method according to claim 12, characterized in that, The reaction temperature of the two-step hydrocyanation reaction method is 40-80℃.

14. The hydrocyanation reaction method according to claim 11, characterized in that, In the two-step hydrocyanation reaction method, X in the structure of the aromatic amine 1 X 3 Y 1 Y 3 The groups are selected from any one of hydrogen, alkyl, or alkoxy, X 2 Y 2 The groups are selected from alkoxy or alkylamine groups, respectively; And / or, in the two-step hydrocyanation reaction method, the mass ratio of nickel-monodentate phosphite ligand catalyst to pentenoic acid is (0.5-3):1000.

15. The hydrocyanation reaction method according to claim 14, characterized in that, In the two-step hydrocyanation reaction method, the mass ratio of nickel-monodentate phosphite ligand catalyst to pentenenitrile is (0.75-2.5):1000.

16. The hydrocyanation reaction method according to claim 11, characterized in that, The two-step hydrocyanation reaction method is carried out in the presence of a co-catalyst, which is at least one of zinc chloride, aluminum chloride, ferric chloride, titanium tetrachloride, and triphenylboron.

17. The hydrocyanation reaction method according to claim 11, characterized in that, The mass ratio of the nickel-monodentate phosphite ligand catalyst to the co-catalyst is (0.2-0.8):

1.

18. The hydrocyanation reaction method according to claim 17, characterized in that, The mass ratio of the nickel-monodentate phosphite ligand catalyst to the co-catalyst is (0.3-0.7):1.

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