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-bidentate 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 provided by the application not only has high reaction efficiency, but also can significantly reduce or eliminate the accumulation of ligand hydrolysis products, and stabilize the effective content of the catalyst in the reaction system; in addition, the hydrocyanation reaction method provided by the application has high reaction efficiency, few side reactions, high raw material conversion rate and high product selectivity, and can meet the needs of a large-scale production process of adiponitrile prepared by directly hydrocyanating 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 reaction, 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); a 2M3BN isomerization reaction, in which 2M3BN undergoes an isomerization reaction to convert to 3PN in the presence of a nickel catalyst; a second-step hydrocyanation reaction, 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, numerous challenges arise. First, the presence of water in the reaction system may cause hydrolysis of the phosphite ligands in the nickel catalyst, producing acidic hydrolysis products, further accelerating ligand hydrolysis and gradually deactivating the nickel-bident phosphite ligand catalyst. Second, when the HCN concentration in the reaction system is high, it attacks 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) is slow and has a long residence time, resulting in a high amount of catalyst deactivation. In addition, the occurrence of side reactions in the hydrocyanation reaction (such as the large amount of 2-methylglutaronitrile byproduct of the two-step hydrocyanation reaction) limits downstream applications, not only reducing reaction efficiency but also increasing production costs.

[0010] Therefore, developing a hydrocyanation reaction process with high reaction efficiency, high catalyst stability, and high product selectivity is an urgent technical problem to be solved. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention discloses a hydrocyanation reaction in which a specific nickel-bident phosphite ligand catalyst and an aromatic amine are used to catalyze the hydrocyanation reaction. This can improve the conversion rate of raw materials and the selectivity of products, reduce the occurrence of side reactions, significantly reduce catalyst consumption, and improve the overall stability of the process.

[0012] To achieve the above technical objectives, on the one hand, this invention proposes a hydrocyanation reaction, wherein the hydrocyanation reaction is carried out in a reaction system containing an aromatic amine under the action of a nickel-bident phosphite ligand catalyst, wherein the aromatic amine has the following structure:

[0013]

[0014] 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.

[0015] The above technical solution uses nickel-bident phosphite ligands as catalysts. In the hydrocyanation reaction, the bidentate phosphite ligands, compared to traditional monodentate phosphite ligands, have a weaker complexation with metallic nickel, making them easier to release and generate active nickel intermediates to promote the hydrocyanation reaction. However, at the same time, 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, causing catalyst loss. The aromatic amines used in the above technical solution have a strong complexation effect with metallic nickel, which can coordinate with the active nickel intermediates in a timely manner during the reaction, thereby protecting the active nickel intermediates and reducing catalyst loss.

[0016] Therefore, the hydrocyanation reaction of the present invention, through the synergistic optimization of nickel-bident phosphite ligand catalyst and aromatic amine, can reduce catalyst loss and by-product formation during the hydrocyanation reaction, and efficiently catalyze the hydrocyanation reaction.

[0017] 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.

[0018] In some alternative examples of the present invention, the aromatic amine may be selected from any of those in Table 1.

[0019] Table 1

[0020]

[0021]

[0022] In a further example of the invention, the structure of the ligand used in the nickel-bident phosphite ligand catalyst was optimized. Optionally, the structure of the ligand used in the nickel-bident phosphite ligand catalyst is as follows:

[0023]

[0024] Among them, R 1 -R 4 and Z 1 -Z 5 The groups include any one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, and methoxy groups. In specific processes, those skilled in the art can select appropriate bidentate phosphite ligands as needed.

[0025] In a further example of the present invention, the ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine in the hydrocyanation reaction was explored and optimized. Optionally, the mass ratio of the nickel-bidentate 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 and improves the stability of the catalyst.

[0026] In a further example of the present invention, the ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine in the hydrocyanation reaction was explored and optimized. Optionally, the mass ratio of the nickel-bidentate 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 and improves the stability of the catalyst.

[0027] In a further example of the present invention, the hydrocyanation reaction method is a hydrocyanation reaction method for preparing adiponitrile.

[0028] Furthermore, the hydrocyanation reaction method includes a one-step hydrocyanation reaction method for preparing pentenonitrile from butadiene.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] Furthermore, in the one-step hydrocyanation reaction method, the mass ratio of nickel-bident phosphite ligand catalyst to butadiene is (0.5-3):1000, preferably (0.75-2.5):1000. By adding a trace amount of a specific aromatic amine, 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 a high-purity pentene nitrile product can be obtained by a separation and purification process, such as extraction, distillation or extractive distillation.

[0034] Furthermore, the hydrocyanation reaction method also includes a two-step hydrocyanation reaction method for preparing adiponitrile from pentenonitrile.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Furthermore, in the two-step hydrocyanation reaction method, the mass ratio of the nickel-bident 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.

[0040] 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.

[0041] Furthermore, the mass ratio of the nickel-bident 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.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows: The hydrocyanation reaction method of the present invention includes a nickel-bident phosphite ligand catalyst and an aromatic amine with a specific structure, which can not only reduce the reaction time of the catalyzed hydrocyanation reaction method, but also significantly reduce or eliminate the accumulation of ligand hydrolysis products and stabilize the effective content of catalyst in the reaction body; in addition, the hydrocyanation reaction method of the present invention has high reaction efficiency, few side reactions, high raw material conversion rate and product selectivity, which can meet the needs of large-scale butadiene direct hydrocyanation to adiponitrile production process. Attached Figure Description

[0043] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0044] Figure 1 The gas chromatogram of Example 5 of the present invention after 2 hours of reaction is shown. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] It should be noted that in the nickel-bident phosphite ligand catalyst described in this invention, the coordination number of nickel to bidentent phosphite ligand is generally 2 or 3, generally 2. 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 describe the ratio of each nickel to bidentent phosphite ligand.

[0048] Regarding the conversion rate of the hydrocyanation reaction method, it is calculated using the percentage of peak area in gas chromatography. Specifically, the conversion rate of the one-step hydrocyanation reaction method is (2M3BN+3PN) / (2M3BN+3PN+butadiene)×100%, and the selectivity of 3PN is 3PN / (2M3BN+3PN)×100%. The conversion rate of the two-step hydrocyanation reaction method is (ADN+MGN) / (ADN+MGN+3PN)×100%, and the selectivity of ADN is ADN / (ADN+MGN)×100%.

[0049] The content of the catalyst in the reaction system of this invention embodiment can be characterized by the Ni content in the clear liquid.

[0050] Example 1

[0051] A one-step hydrocyanation reaction method, which uses butadiene as a raw material to prepare pentenenitrile in a reaction system containing aromatic amines and catalyzed by a nickel-bident phosphite ligand catalyst, specifically:

[0052] (1) Material preparation: The catalyst used in this embodiment is a nickel-bident phosphite ligand catalyst, wherein the structural formula of the bidentent phosphite ligand L21 is:

[0053]

[0054] Having the substituent structures shown in Table 2:

[0055] Table 2

[0056] Ligand L21 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents Isopropyl hydrogen methyl hydrogen methyl hydrogen tert-butyl hydrogen methyl

[0057] Nickel-bident phosphite ligand catalyst was prepared by reacting ligand L21 with nickel powder.

[0058] 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-bident phosphite ligand catalysts in the embodiments of the invention are merely preferred demonstrations. Those skilled in the art can prepare the ligands or nickel-bident phosphite ligand catalysts through other methods without inventive effort, and under certain operating conditions, suitable types of ligands or nickel-bident 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.

[0059] (2) One-step hydrocyanation reaction method: Nickel-bident phosphite ligand catalyst (2 mmol), aromatic amine A2 (1.0 mmol) and butadiene (2.0 mol) were placed in a stainless steel reactor, purged with nitrogen, and the reaction system was heated to 50°C. Then, hydrocyanic acid (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, the reaction system was sampled and analyzed at different times. The results are shown in Table 3.

[0060] Table 3

[0061] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 32.35 61.16 6.49 353 67.65 90.41 2 22.52 69.13 8.35 339 77.48 89.22 3 17.16 74.61 8.23 337 82.84 90.07 4 10.15 80.72 9.13 331 89.85 89.84 5 3.23 86.54 10.23 329 96.77 89.43

[0062] As can be seen from Table 3, in the one-step hydrocyanation involving a nickel-bident phosphite ligand catalyst with a bidentate structure and aromatic amine A2, the selectivity of 3PN reached about 90%, with few side reactions; and the Ni content in the clear liquid did not change much during the reaction, indicating that the catalyst performance was relatively stable during the reaction.

[0063] Example 2

[0064] 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-bident phosphite ligand catalyst, specifically:

[0065] (1) Material preparation: The catalyst used in this embodiment is a nickel-bident phosphite ligand catalyst, wherein the structure of bidentent phosphite ligand L22 is the same as that of ligand L21, but ligand L22 has the substituent structures shown in Table 4:

[0066] Table 4

[0067] Ligand L22 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents Isopropyl methyl methyl hydrogen methyl Ethyl tert-butyl hydrogen methyl

[0068] Nickel-bident phosphite ligand catalyst was prepared by reacting ligand L22 with nickel powder.

[0069] (2) One-step hydrocyanation reaction method: The nickel-bident phosphite ligand catalyst (5 mmol), aromatic amine A4 (0.5 mmol) and butadiene (2.0 mol) were placed in a stainless steel reactor, purged with nitrogen, and the reaction system was heated to 95°C. Then, hydrocyanic acid (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 95°C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 5.

[0070] Table 5

[0071] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 31.25 62.23 6.52 345 68.75 90.52 2 21.52 70.14 8.34 339 78.48 89.37 3 16.21 76.15 7.64 340 83.79 90.88 4 9.25 81.72 9.03 342 90.75 90.05 5 3.25 86.45 10.3 339 96.75 89.35

[0072] As can be verified from Table 5, the one-step hydrocyanation reaction method catalyzed by the catalyst combination of the present invention has high feed conversion rate and product selectivity, few side reactions, high catalyst retention rate, and stable catalytic performance.

[0073] Example 3

[0074] 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-bident phosphite ligand catalyst, specifically:

[0075] (1) Material preparation: The catalyst used in this embodiment is a nickel-bident phosphite ligand catalyst, wherein the structure of bidentent phosphite ligand L23 is the same as that of ligand L21, but ligand L23 has the substituent structures shown in Table 6:

[0076] Table 6

[0077] Ligand L23 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents methyl Isopropyl tert-butyl methoxy methyl methyl hydrogen methyl Isopropyl

[0078] Nickel-bident phosphite ligand catalyst was prepared by reacting ligand L23 with nickel powder.

[0079] (2) One-step hydrocyanation reaction method: Nickel-bident phosphite ligand catalyst (7.5 mmol), aromatic amine A5 (3.0 mmol) and butadiene (5.0 mol) were placed in a stainless steel reactor, purged with nitrogen, and the reaction system was heated to 75°C. Then, hydrocyanic acid (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 75°C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 7.

[0080] Table 7

[0081] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 32.75 60.75 6.5 338 67.25 90.33 2 22.12 70.13 7.75 329 77.88 90.05 3 16.23 75.75 8.02 326 83.77 90.43 4 9.01 81.95 9.04 335 90.99 90.06 5 4.05 86.65 9.3 340 95.95 90.31

[0082] As can be seen from Table 7, under the combined action of the nickel-bident phosphite ligand catalyst and the aromatic amine A5 catalyst of the present invention, the selectivity of 3PN in the one-step hydrocyanation reaction method is about 90%, and the Ni content in the clear liquid does not change much with time during the reaction, indicating that the catalyst is relatively stable during the reaction.

[0083] Example 4

[0084] A one-step hydrocyanation reaction method is provided. The catalyst, reaction raw materials and control parameters used in this reaction are the same as those in Example 1. The difference is that the aromatic amine added in this example is aromatic amine A11. As the reaction proceeds, the reaction system is sampled and analyzed at different times. The results are shown in Table 8.

[0085] Table 8

[0086] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 39.25 54.77 5.98 343 60.75 90.16 2 30.31 63.05 6.64 332 69.69 90.47 3 23.22 69.17 7.61 319 76.78 90.09 4 14.75 76.58 8.67 303 85.25 89.83 5 8.35 82.54 9.11 287 91.65 90.06

[0087] Combining Tables 3 and 8, the one-step hydrocyanation reaction method containing aromatic amine A2 is relatively better than the one-step hydrocyanation reaction method containing aromatic amine A11. 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.

[0088] Example 5

[0089] 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-bident phosphite ligand catalyst, specifically:

[0090] (1) Material preparation: The catalyst used in this embodiment is a nickel-bident phosphite ligand catalyst, wherein the structure of bidentent phosphite ligand L24 is the same as that of ligand L21, but ligand L24 has the substituent structures shown in Table 9:

[0091] Table 9

[0092]

[0093]

[0094] Nickel-bident phosphite ligand catalyst was prepared by reacting ligand L24 with nickel powder.

[0095] (2) Two-step hydrocyanation reaction method: Nickel-bident phosphite ligand catalyst (2 mmol), anhydrous zinc chloride (3 mmol), aromatic amine A11 (0.25 mmol) and 3PN (0.8 mol) were placed in a stainless steel reactor, purged with nitrogen, and the reaction system was heated to 80 °C. Then, hydrogen cyanide (0.76 mol) was slowly added to the reactor by a pump for 2 hours. After the addition was completed, the reaction was continued at 80 °C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 10. Figure 1 The gas chromatogram of this embodiment at 2 hours is shown.

[0096] Table 10

[0097] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 63.9 34.68 1.42 340 36.10 96.07 4 42.9 54.89 2.21 335 57.10 96.13 6 26.7 70.77 2.53 332 73.30 96.55 8 10.5 86.01 3.49 329 89.50 96.10 10 2.3 93.95 3.75 326 97.70 96.16

[0098] As can be verified by Table 10, in the two-step hydrocyanation involving nickel-bident phosphite ligand catalyst and aromatic amine A11, the selectivity of ADN reached over 96%, with few side reactions, and the Ni content in the supernatant did not change much during the overall reaction process, indicating that the catalyst performance was relatively stable.

[0099] Example 6

[0100] 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-bident phosphite ligand catalyst, specifically:

[0101] (1) Material preparation: The catalyst used in this embodiment is a nickel-bident phosphite ligand catalyst, wherein the structure of bidentent phosphite ligand L25 is the same as that of ligand L21, but ligand L25 has the substituent structures shown in Table 11:

[0102] Table 11

[0103] Ligand L25 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents tert-butyl hydrogen methyl methoxy Isopropyl hydrogen methoxy Ethyl methyl

[0104] Nickel-bident phosphite ligand catalyst was prepared by reacting ligand L25 with nickel powder.

[0105] (2) Two-step hydrocyanation reaction method: Nickel-bident phosphite ligand catalyst (0.75 mmol), anhydrous titanium tetrachloride (2.5 mmol), aromatic amine A12 (0.45 mmol) and 3PN (1.0 mol) were placed in a stainless steel reactor, purged with nitrogen, and the reaction system was heated to 40 °C. Then, hydrogen cyanide (0.95 mol) was slowly added to the reactor by pump for 2 hours. After the addition was completed, the reaction was continued at 40 °C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 12.

[0106] Table 12

[0107] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 65.2 33.28 1.52 338 34.80 95.63 4 43.1 54.12 2.78 345 56.90 95.11 6 27.9 68.77 3.33 329 72.10 95.38 8 12.5 84.04 3.46 331 87.50 96.05 10 4.3 91.85 3.85 339 95.70 95.98

[0108] As can be seen from Table 12, the feed conversion rate of the two-step hydrocyanation reaction method of the present invention, which involves a nickel-bident phosphite ligand catalyst and aromatic amine A12, can reach 95.7%, the selectivity of ADN can reach more than 96%, and the catalyst content is stable throughout the reaction process, with good catalyst stability.

[0109] Example 7

[0110] 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-bident phosphite ligand catalyst, specifically:

[0111] (1) Material preparation: The catalyst used in this embodiment is a nickel-bident phosphite ligand catalyst, wherein the structure of bidentent phosphite ligand L26 is the same as that of ligand L21, but ligand L26 has the substituent structures shown in Table 13:

[0112] Table 13

[0113] Ligand L26 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> <![CDATA[R 4 ]]> <![CDATA[Z 1 ]]> <![CDATA[Z 2 ]]> <![CDATA[Z 3 ]]> <![CDATA[Z 4 ]]> <![CDATA[Z 5 ]]> Substituents methyl Isopropyl tert-butyl methyl methyl methyl hydrogen methyl tert-butyl

[0114] Nickel-bident phosphite ligand catalyst was prepared by reacting ligand L26 with nickel powder.

[0115] (2) Two-step hydrocyanation reaction method: Nickel-bident phosphite ligand catalyst (4.0 mmol), triphenylboron (8.0 mmol), aromatic amine A10 (2.0 mmol) and 3PN (2.0 mol) were placed in a stainless steel reactor, purged with nitrogen, and the reaction system was heated to 60 °C. Then, hydrocyanic acid (1.95 mol) was slowly added to the reactor by a pump for 2 hours. After the addition was completed, the reaction was continued at 60 °C. As the reaction proceeded, the reaction system was sampled and analyzed at different times. The results are shown in Table 14.

[0116] Table 14

[0117] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 65.7 33.18 1.12 345 34.3 96.73 4 44.1 53.89 2.01 347 55.9 96.40 6 28.1 69.18 2.72 328 71.9 96.22 8 12.7 83.92 3.38 335 87.3 96.13 10 4.5 91.75 3.75 337 95.5 96.07

[0118] As can be verified by Table 14, the selectivity of ADN in the two-step hydrocyanation using the present invention, which includes a nickel-bident phosphite ligand catalyst and an aromatic amine A10, can reach over 96%, and the Ni content in the supernatant does not decrease significantly during the reaction process, indicating that the catalytic performance of the catalyst is relatively stable during the reaction.

[0119] Example 8

[0120] A two-step hydrocyanation reaction method is provided. The catalyst, reaction raw materials and control parameters used in this reaction are the same as those in Example 5. The difference is that the aromatic amine added in this example is aromatic amine A2. As the reaction proceeds, the reaction system is sampled and analyzed at different times. The results are shown in Table 15.

[0121] Table 15

[0122] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 70.3 28.53 1.17 340 29.70 96.06 4 52.3 45.79 1.91 322 47.70 96.00 6 36.57 61.03 2.4 298 63.43 96.22 8 21.52 75.34 3.14 285 78.48 96.00 10 12.11 84.56 3.33 264 87.89 96.21

[0123] As can be seen from Tables 10 and 15, compared with the two-step hydrocyanation reaction method using aromatic amine A2, the two-step hydrocyanation reaction method using aromatic amine A11 has higher catalyst stability and better reaction rate performance. In actual reaction process, different aromatic amines can be selected for catalyzing the two-step hydrocyanation reaction method according to specific working conditions.

[0124] Comparative Example 1

[0125] A one-step hydrocyanation reaction method is described. The catalyst, reaction raw materials, and control parameters used in this reaction are the same as those in Example 1. The difference is that no aromatic amine is added in this comparative example. As the reaction proceeds, the reaction system is sampled and analyzed at different times. The results are shown in Table 16.

[0126] Table 16

[0127] Reaction time / h Butadiene / wt% 3PN / wt% 2M3BN / wt% Ni / ppm of clear liquid Conversion rate / % 3PN selectivity / % 1 45.52 49.57 4.91 353 54.48 90.99 2 37.21 56.65 6.14 310 62.79 90.22 3 29.21 63.76 7.03 260 70.79 90.07 4 19.54 71.99 8.47 223 80.46 89.47 5 13.23 78.23 8.54 175 86.77 90.16

[0128] Combined with Tables 3 and 16, it can be confirmed that the one-step hydrocyanation reaction method of the present invention contains an aromatic amine with a specific structure, which makes the Ni content of the supernatant of the catalyzed one-step hydrocyanation reaction method relatively stable during the reaction process. Compared with Example 1, the Ni content of the supernatant in Comparative Example 1 decreased faster (the Ni content of the supernatant decreased to 50% of the initial amount after 5 hours of reaction), verifying that the aromatic amine A2 in the hydrocyanation reaction method of the present invention has a good effect on stabilizing the catalyst. In addition, the rate of the one-step hydrocyanation reaction method in Comparative Example 1 is slower than that in Example 1, confirming that the aromatic amine A2 in the hydrocyanation reaction method of the present invention has a good effect on improving the reaction rate.

[0129] Comparative Example 2

[0130] A two-step hydrocyanation reaction method is described. The catalyst, reaction raw materials, and control parameters used in this reaction are the same as those in Example 5. The difference is that no aromatic amine is added in this comparative example. As the reaction proceeds, the reaction system is sampled and analyzed at different times. The results are shown in Table 17.

[0131] Table 17

[0132] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 75.6 23.44 0.96 340 24.40 96.07 4 61.3 37.22 1.48 302 38.70 96.18 6 46.7 51.2 2.1 264 53.30 96.06 8 30.21 67.01 2.78 225 69.79 96.02 10 20.11 76.75 3.14 187 79.89 96.07

[0133] As can be verified by referring to Tables 10 and 17, the two-step hydrocyanation reaction method of the present invention contains an aromatic amine with a specific structure, which plays a role in stabilizing the catalyst (nickel content) in the reaction system. In Comparative Example 2, the Ni content in the clear liquid decreased rapidly (the Ni content in the clear liquid decreased to 55% of the original after 10 hours of reaction), while in Example 5, the Ni content in the clear liquid remained at 96% of the initial amount after 10 hours. In addition, the reaction rate of the two-step hydrocyanation in Example 5 was greater than that in Comparative Example 4, verifying that the aromatic amine A11 has a better effect on improving the reaction rate.

[0134] Comparative Example 3

[0135] A one-step hydrocyanation reaction method is disclosed, which prepares pentenonitrile from butadiene in the presence of a nickel-monodentate phosphite ligand catalyst and aromatic amine A2; wherein the result of the monodentate phosphite ligand L11 is as follows:

[0136]

[0137] The monodentate phosphite ligand L11 has the substituent structures shown in Table 18:

[0138] Table 18

[0139] Ligand L11 <![CDATA[R 1 ]]> <![CDATA[R 2 ]]> <![CDATA[R 3 ]]> Substituents Isopropyl hydrogen methyl

[0140] Nickel-monodentate phosphite ligand catalyst was prepared by reacting ligand L11 with nickel powder.

[0141] In this comparative example, the raw materials and control parameters of the one-step hydrocyanation reaction method are the same as those in Example 1. As the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 19.

[0142] Table 19

[0143]

[0144]

[0145] As can be confirmed by combining Tables 3 and 19, the nickel-bident phosphite ligand catalyst used in the hydrocyanation reaction method of the present invention has higher product selectivity in the one-step hydrocyanation reaction process compared with the nickel-monodentate phosphite ligand catalyst used in Comparative Example 3, reflecting that the bidentate phosphite ligand plays an important role in improving the selectivity of 3PN; in addition, the Ni content of the supernatant did not change much during the reaction process of Example 1 and Comparative Example 3, confirming the effect of aromatic amine A2 in stabilizing catalyst performance.

[0146] Comparative Example 4

[0147] A two-step hydrocyanation reaction method is disclosed, wherein the reaction is carried out in the presence of a nickel-monodentate phosphite ligand catalyst and an aromatic amine A11 to prepare pentenonitrile from butadiene; wherein the nickel-monodentate phosphite ligand catalyst is prepared by ligand L11 and nickel powder.

[0148] In this comparative example, the raw materials and control parameters of the two-step hydrocyanation reaction method are the same as those in Example 5. As the reaction proceeds, the reaction system is sampled and analyzed at different times, and the results are shown in Table 20.

[0149] Table 20

[0150] Reaction time / h 3PN / wt% ADN / wt% MGN / wt% Ni / ppm of clear liquid Conversion rate / % ADN selectivity / % 2 80.9 15.7 3.4 340 19.10 82.20 4 62.9 30.55 6.55 335 37.10 82.35 6 46.72 43.75 9.53 332 53.28 82.11 8 29.52 57.78 12.7 329 70.48 81.98 10 19.95 65.56 14.49 326 80.05 81.90

[0151] As can be verified by combining Tables 10 and 20, the hydrocyanation reaction method of the present invention uses a nickel-bidentate phosphite ligand catalyst, which, compared with the nickel-monodentate phosphite ligand catalyst used in Comparative Example 4, exhibits higher product selectivity in the two-step hydrocyanation reaction process, reflecting the important role of the bidentate phosphite ligand in improving the 3PN selectivity. In addition, the Ni content in the supernatant of the reaction solution did not change much during the reaction of Example 5 and Comparative Example 4, verifying that the aromatic amine A11 played a role in stabilizing the catalyst performance during the two-step hydrocyanation process.

[0152] Comparative Example 5

[0153] A two-step hydrocyanation reaction method was described. The catalyst, reactants, and control parameters used in this reaction were the same as in Example 5, except that A11-1 containing one aromatic ring and A11-2 containing three aromatic rings were used instead of A11 in this comparative example. As the reaction proceeded, samples of the reaction system were taken at different times for analysis, and the results are shown in Table 21.

[0154]

[0155] Table 21

[0156]

[0157] As can be verified by referring to Tables 10 and 21, the hydrocyanation reaction method of the present invention contains an aromatic amine with a specific structure, which plays a role in stabilizing the catalyst (nickel content) in the reaction system. Specifically, in Comparative Example 5, the Ni content in the clear liquid decreased more rapidly (after 10 hours of reaction, the Ni content in the clear liquid decreased to 75% and 72% of the original, respectively), while in Example 5, the Ni content in the clear liquid remained at 96% of the initial amount after 10 hours. This indicates that the aromatic amine with a specific structure contained in the hydrocyanation reaction method of the present invention is more conducive to stabilizing the catalyst and reducing catalyst loss. In addition, the reaction rate of the two-step hydrocyanation in Example 5 is greater than that in Comparative Example 5, verifying that aromatic amine A11 is superior to A11-1 containing one aromatic ring and A11-2 containing three aromatic rings in improving the reaction rate.

[0158] 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 hydrocyanation process characterized by, The hydrocyanation reaction method is carried out in a reaction system containing an aromatic amine, under the action of a nickel-bidentate phosphite ligand catalyst, and the structure of the aromatic amine is: ， wherein X 1 -X 3 group and Y 1 -Y 3 are each selected from any one of hydrogen, alkyl, alkoxy, alkylamine, hydroxyl, and amino; the alkyl has a structural formula of , the alkoxy has a structural formula of , and the alkylamine has a structural formula of , wherein the R group is selected from any one of methyl, ethyl, isopropyl, and tert-butyl. The structure of the bidentate phosphite ligand is: ， wherein R 1 - R 4 and Z 1 - Z 5 is selected from any one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, methoxy; The hydrocyanation reaction method is a hydrocyanation reaction method for preparing adiponitrile.

2. The hydrocyanation process of claim 1 wherein, The mass ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine is 1: (0.05-0.8).

3. The hydrocyanation process of claim 2 wherein, The mass ratio of the nickel-bidentate phosphite ligand catalyst to the aromatic amine is 1: (0.1-0.6).

4. The hydrocyanation process of claim 1 wherein, The hydrocyanation reaction method is a one-step hydrocyanation reaction method for preparing pentenenitrile from butadiene.

5. The hydrocyanation process of claim 4 wherein, The reaction temperature of the one-step hydrocyanation reaction method is 40-110°C.

6. The hydrocyanation process of claim 5 wherein, The reaction temperature of the one-step hydrocyanation reaction method is 50-95°C.

7. The hydrocyanation process of claim 4 wherein, In the one-step hydrocyanation process, the X 1 , X 3 , Y 1 , Y 3 groups in the structure of the aromatic amine are selected from hydrogen or alkyl, respectively, and the X 2 , Y 2 groups are selected from alkyl or alkoxy, respectively. And / or, the mass ratio of the nickel-bidentate phosphite ligand catalyst to butadiene in the one-step hydrocyanation reaction method is (0.5-3): 1000.

8. The hydrocyanation process of claim 7 wherein, The mass ratio of the nickel-bidentate phosphite ligand catalyst to butadiene in the one-step hydrocyanation reaction method is (0.75-2.5): 1000.

9. The hydrocyanation process of claim 1 wherein, The hydrocyanation reaction method is a two-step hydrocyanation reaction method for preparing adiponitrile from pentenenitrile.

10. The hydrocyanation process of claim 9 wherein, The reaction temperature of the two-step hydrocyanation reaction method is 35-90°C.

11. The hydrocyanation process of claim 10 wherein, The reaction temperature of the two-step hydrocyanation reaction method is 40-80°C.

12. The hydrocyanation process of claim 9 wherein, In the two-step hydrocyanation process, the X 1 , X 3 , Y 1 , Y 3 groups in the structure of the aromatic amine are each selected from any one of hydrogen, alkyl or alkoxy, the X 2 , Y 2 groups are selected from alkoxy or alkylamine groups; And / or, the mass ratio of the nickel-bidentate phosphite ligand catalyst to pentenenitrile in the two-step hydrocyanation reaction method is (0.5-3): 1000.

13. The hydrocyanation process of claim 12 wherein, The mass ratio of the nickel-bidentate phosphite ligand catalyst to pentenenitrile in the two-step hydrocyanation reaction method is (0.75-2.5): 1000.

14. The hydrocyanation process of claim 9 wherein, The two-step hydrocyanation reaction method is carried out in the presence of a co-catalyst selected from one of zinc chloride, aluminum chloride, iron chloride, titanium tetrachloride, and triphenylboron.

15. The hydrocyanation process of claim 14 wherein, The mass ratio of the nickel-bidentate phosphite ligand catalyst to the co-catalyst is (0.2-0.8):

1.

16. The hydrocyanation process of claim 15 wherein, The mass ratio of the nickel-bidentate phosphite ligand catalyst to the co-catalyst is (0.3-0.7): 1.

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