A method for catalytic synthesis of α-alkylbutyronitrile compounds

Abstract

This invention belongs to the field of organic synthetic chemistry and discloses a method for the catalytic synthesis of α-alkylbutadiene nitrile compounds. Using styrene and phenylacetonitrile compounds as substrates, the method involves a catalytic reaction at 120-160°C for 6-16 hours under a nitrogen atmosphere, with the combined action of a palladium catalyst and KOH, to obtain α-alkylbutadiene nitrile compounds. This invention achieves the α-alkylation of phenylacetonitrile without the need for complex metal complexes as catalysts or excessive alkylation substrates. Furthermore, the catalyst of this invention can be reused multiple times, exhibits good stability, and the reaction is mild.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis chemistry, specifically relating to a method for synthesizing α-alkylbutadiene nitrile using styrene and phenylacetonitrile as substrates under the action of a Pd / ETS-10 catalyst. Background Technology

[0002] Nitriles are important functional groups ubiquitously found in natural products, agrochemicals, pharmaceuticals, and polymers. Among them, α-alkyl nitriles are unique structural units in organic synthesis and bioactive molecules. They are common precursors for the synthesis of a wide variety of compounds, such as aldehydes, ketones, carboxylic acids, esters, amides, and amines, and possess diverse functions. Therefore, developing novel and efficient synthetic methods for the selective synthesis of α-alkyl nitriles is crucial for both organic chemistry and medicinal chemistry. Among the various strategies developed for the preparation of alkylbutyronitrile, transition metal-catalyzed hydrogen transfer reactions using phenethyl alcohol and phenylacetonitrile as starting materials are a direct and efficient method. However, these methods heavily rely on the use of metal complexes, such as Mn (Journal of Organic Chemistry 2019, 84, 7927-7935), Ni (Chem. Commun. 2020, 56, 6850-6853), and Co (Organometallics 2022, 41, 3145-3151). Furthermore, although Wu Guojiao and colleagues achieved alkylation of nitriles using the deamination coupling of α-aminoacetonitrile with arylboronic acid (Angew. Chem. Int. Ed. 2014, 53, 10510-10514), and Ross achieved alkylation of nitriles using cyanide reagents catalyzed by metallic nickel (Eur. J. Org. Chem. 2023, 26, e202300050), these methods generally require catalysis by metal complexes and the addition of organic ligands, leading to complexity in catalyst separation and product purification. Moreover, these methods require excessive alkylation substrates to achieve high yields, resulting in poor atom economy. These problems severely hinder further applications in the pharmaceutical and industrial sectors.

[0003] Therefore, there is an urgent need to develop a simple, efficient, and mild catalytic system for the synthesis of α-alkyl nitriles. Based on this, this invention innovatively develops a heterogeneous catalytic system: using metal-supported ETS-10 as a catalyst for the α-alkylation of phenylacetonitrile. Compared with other routes, this method significantly improves the yield of α-alkyl nitrile compounds while being environmentally friendly. Summary of the Invention

[0004] With the aid of Pd / ETS-10 catalyst, a 100% atom-economic α-alkylation synthesis was achieved using styrene-based compounds and phenylacetonitrile compounds as substrates.

[0005] The features of this invention are: ① Pd / ETS-10 zeolite has good stability and can be recycled multiple times, which has economic value; ② The reaction conditions are mild and the reaction efficiency is high; ③ 100% atom economy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] Using styrene compounds and phenylacetonitrile compounds as substrates, a predetermined amount of Pd / ETS-10 catalyst and base were added to a reaction tube, followed by the addition of quantitative amounts of styrene compounds and phenylacetonitrile compounds. The reaction was carried out under a nitrogen atmosphere at a target reaction temperature. The resulting product was then centrifuged and rotary evaporated, and the liquid product was separated by column chromatography to obtain pure α-alkylbutadiene nitrile.

[0008]

[0009] R1 is derived from hydrogen, 2-methyl, 4-methyl, 3-fluoro, 4-fluoro, or 3-chloro substituents. R2 is derived from hydrogen, 4-methyl, 3-methyl, 4-methoxy, 4-chloro, or 2-fluoro substituents.

[0010] The reaction temperature in this invention is 120-160℃, preferably 150℃.

[0011] The reaction time in this invention is 6-16 hours, preferably 12 hours.

[0012] The reaction solvent in this invention can be one of dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF), preferably N,N-dimethylformamide (DMF).

[0013] Furthermore, the molar ratio of phenylacetonitrile compounds to styrene compounds is 2:3 to 1:4, preferably 1:2.

[0014] The molar ratio of phenylacetonitrile to KOH is 2:1 to 1:2, with 1:1 being the preferred ratio.

[0015] Furthermore, the source of ETS-10 zeolite is not limited. Mesoporous ETS-10 zeolite is preferred, as it is more conducive to the reaction. The specific surface area and other parameters of ETS-10 containing a mesoporous structure are required as follows: specific surface area 350–450 m² / g. 2 / g, mesoporous pore volume is 0.1~0.2cm 3 / g, with an external surface area of ​​80–120m² 2 / g, with micropore volume of 0.09–0.16 cm³. 3 / g.

[0016] The palladium loading in Pd / ETS-10 zeolite is 1%–7% by mass, preferably 1%–3%. It can be prepared by conventional equal-volume impregnation method.

[0017] Furthermore, the molar ratio of the phenylacetonitrile compound to the mass of Pd / ETS-10 zeolite is 1:100 to 1:200 mol / g, preferably 1:125 to 1:175 mol / g.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The conditions are simple, no complex metal complexes are needed as catalysts, and no excessive alkylation substrates are required to efficiently synthesize the target product.

[0020] (2) Pd / ETS-10 zeolite is easy to separate and recover, can be reused multiple times, has good stability, and has economic value and industrial significance. Attached Figure Description

[0021] Figure 1 It is the 2,4-diphenylbutyronitrile obtained in Example 1. 1 H-NMR spectrum.

[0022] Figure 2 It is the 2-(4-chlorophenyl)-4-phenylbutyronitrile obtained in Example 7. 1 H-NMR spectrum.

[0023] Figure 3 It is the 2-(4-methoxyphenyl)-4-phenylbutyronitrile obtained in Example 8. 1 H-NMR spectrum.

[0024] Figure 4 It is the 4-phenyl-2-(p-tolyl)butyronitrile obtained in Example 9. 1 H-NMR spectrum.

[0025] Figure 5 It is the 2-(2-fluorophenyl)-4-phenylbutyronitrile obtained in Example 10. 1 H-NMR spectrum.

[0026] Figure 6 This is the gas phase mass spectrum of 4-phenyl-2-(m-tolyl)butyronitrile obtained in Example 11.

[0027] Figure 7 This is the gas phase mass spectrum of 4-(4-fluorophenyl)-2-phenylbutyronitrile obtained in Example 12.

[0028] Figure 8 This is the gas phase mass spectrum of 4-(3-fluorophenyl)-2-phenylbutyronitrile obtained in Example 13.

[0029] Figure 9 It is the 2-phenyl-4-(p-tolyl)butyronitrile obtained in Example 14. 1 H-NMR spectrum.

[0030] Figure 10 This is the gas phase mass spectrum of 4-(3-chlorophenyl)-2-phenylbutyronitrile obtained in Example 15.

[0031] Figure 11 This is the gas phase mass spectrum of 2-phenyl-4-(o-tolyl)butyronitrile obtained in Example 16. Detailed Implementation

[0032] To further understand the purpose, content, and advantages of this invention, specific embodiments of the invention are described in detail below. However, this description is not limited to the examples given below, and reaction conditions should be adjusted according to actual circumstances. Unless otherwise specified, the reagents and instruments used in the following examples are commercially available products.

[0033] The ETS-10 zeolite used in the examples was prepared according to previous work of this group, and the specific preparation method is as follows: First, 10.0 mL of NaOH (26.9 wt.%) solution and 11.8 mL of KOH (17.5 wt.%) solution were added to 15.2 mL of water glass and stirred at room temperature for 60 minutes. Then, 13.0 g of TiCl3 (17 wt.%) was slowly added dropwise to the above mixture. The resulting gel was stirred for 2 hours and transferred to a 50 mL autoclave for crystallization at 230 °C for 3 days. After filtration, drying, and calcination at 475 °C for 5 hours, the molar ratio of the reaction gel system was 1.0 TiO2:5.7 SiO2:4.7 Na2O:1.3 K2O:163.0 H2O.

[0034] The specific preparation process of Pd / ETS-10 is as follows: Weigh 0.025g of palladium nitrate into an appropriate amount of distilled water to prepare a palladium nitrate metal salt solution. Add the solution dropwise to 1.0g of ETS-10 zeolite using an equal volume impregnation method. After drying at room temperature for 12 hours, place the solution in a 100℃ oven for 8 hours. Then, calcine the solution in a muffle furnace under an air atmosphere. The calcine program is as follows: increase the temperature from room temperature to 100℃ at a rate of 5℃·min⁻¹, and then increase the temperature at a rate of 3℃·min⁻¹. -1 The temperature was increased from 100℃ to 450℃ and held for 4 hours to obtain a 1% Pd / ETS-10 zeolite catalyst.

[0035] Example 1:

[0036]

[0037] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 89%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as eluent) after rotary evaporation to obtain the product. The characterization data of the product are as follows: 1 H NMR (400MHz, Chloroform-d) δ7.38-7.26(m,7H),7.23-7.15(m,3H),3.71(dd,J=9.0,6.1Hz,1H),2.85-2.71(m,2H),2.18(d,J=32.6Hz,2H).

[0038] Example 2:

[0039] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of dimethyl sulfoxide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 60%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0040] The solvent in Example 2 was replaced with 1 mL of toluene, and other conditions remained unchanged. The conversion and selectivity were determined by GC, and the yield of the product was 22%.

[0041] The solvent in Example 2 was replaced with 1 mL of tetrahydrofuran, and other conditions remained unchanged. The conversion and selectivity were determined by GC, and the yield of the product was 0%.

[0042] Example 3:

[0043] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 110 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 62%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0044] The temperature in Example 3 was increased to 130°C, while other conditions remained unchanged. The conversion and selectivity were determined by GC, and the yield of the product was 78%.

[0045] Example 4:

[0046] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 8 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 64%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0047] The time in Example 4 was increased to 10 hours, while other conditions remained unchanged. The conversion and selectivity were determined by GC, and the product yield was 81%.

[0048] The time in Example 4 was increased to 16 hours, while other conditions remained unchanged. The conversion and selectivity were determined by GC, and the product yield was 73%.

[0049] Example 5:

[0050] 30 mg of 1% Pd / ETS-10 zeolite, 22.4 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 83%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0051] The amount of KOH used in Example 5 was increased to 33.6 mg, while other conditions remained unchanged. The conversion and selectivity were determined by GC, and the yield of the product was 82%.

[0052] Example 6:

[0053] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.4 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 75%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0054] The molar amount of phenylacetonitrile in Example 6 was increased to 0.6 mmol, and other conditions remained unchanged. The conversion and selectivity were determined by GC, and the yield of the product was 69%.

[0055] Example 7:

[0056]

[0057] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of p-chlorophenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2-(4-chlorophenyl)-4-phenylbutyronitrile was calculated to be 74%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as eluent) after rotary evaporation to obtain the product. The characterization data of the product are as follows: 1 H NMR (400MHz, Chloroform-d) δ7.27-7.18(m,4H),7.11(dd,J=21.7,7.8Hz,5H),3.60(dd,J=9.0,6.1Hz,1H),2.76-2.62(m,2H),2.19-1.97(m,2H).

[0058] Example 8:

[0059]

[0060] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of p-methoxyphenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2-(4-methoxyphenyl)-4-phenylbutyronitrile was calculated to be 84%. The reaction solution was then separated by column chromatography (eluting reagent: a mixture of cyclohexane and ethyl acetate) after rotary evaporation to obtain the product. The characterization data of the product are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.32-7.26(m,2H),7.19(dd,J=13.4,8.6Hz,5H),6.88(d,J=8.7Hz,2H),3.78(s,3H),3.69-

[0061] 3.64(m,1H),2.84-2.70(m,2H),2.28-2.06(m,2H).

[0062] Example 9:

[0063]

[0064] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of p-methylphenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 4-phenyl-2-(p-tolyl)butyronitrile was calculated to be 69%. The reaction solution was then separated by column chromatography (eluting reagent: a mixture of cyclohexane and ethyl acetate) after rotary evaporation to obtain the product. The characterization data of the product are as follows: ¹H NMR (400 MHz, Chloroform-d) δ 7.31–7.12 (m, 9H), 3.67 (d, J = 15.1 Hz, 1H), 2.83–2.70 (m, 2H), 2.32 (s, 3H), 2.16 (d, J = 34.6 Hz, 2H).

[0065] Example 10:

[0066]

[0067] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of 2-fluorophenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2-(2-fluorophenyl)-4-phenylbutyronitrile was calculated to be 69%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product. The characterization data of the product are as follows: ¹H NMR (400MHz, Chloroform-d) δ 7.39-7.33 (m, 1H), 7.21 (t, J = 7.9 Hz, 3H), 7.16-7.05 (m, 4H), 7.01-6.94 (m, 1H), 3.96 (dd, J = 8.9, 6.0 Hz, 1H), 2.83-2.64 (m, 2H), 2.21-2.02 (m, 2H), 1.31-1.15 (m, 1H).

[0068] Example 11:

[0069]

[0070] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of m-methylphenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 4-phenyl-2-(m-tolyl)butyronitrile was calculated to be 68%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0071] Example 12:

[0072]

[0073] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of p-fluorostyrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 4-(4-fluorophenyl)-2-phenylbutyronitrile was calculated to be 71%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0074] Example 13:

[0075]

[0076] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of m-fluorostyrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 4-(3-fluorophenyl)-2-phenylbutyronitrile was calculated to be 79%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0077] Example 14:

[0078]

[0079] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of p-methylstyrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2-phenyl-4-(p-tolyl)butyronitrile was calculated to be 70%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product. The characterization data of the product are as follows: ¹H NMR (400MHz, Chloroform-d) δ 7.29–7.17 (m, 5H), 7.00 (q, J = 8.1 Hz, 4H), 3.61 (dd, J = 9.0, 6.1 Hz, 1H), 2.73–2.59 (m, 2H), 2.22 (s, 3H), 2.19–1.97 (m, 2H).

[0080] Example 15:

[0081]

[0082] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of m-chlorostyrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 4-(3-chlorophenyl)-2-phenylbutyronitrile was calculated to be 75%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0083] Example 16:

[0084]

[0085] 30 mg of 1% Pd / ETS-10 zeolite, 11.2 mg of KOH, 0.4 mmol of o-methylstyrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2-phenyl-4-(o-tolyl)butyronitrile was calculated to be 68%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0086] Comparative Example 1:

[0087] 11.2 mg KOH, 30 mg ETS-10 zeolite, 0.4 mmol styrene, 0.2 mmol phenylacetonitrile, and 1 mL N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 65%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0088] Comparative Example 2:

[0089] 11.2 mg KOH, 30 mg 1% Pd / Beta zeolite, 0.4 mmol styrene, 0.2 mmol phenylacetonitrile, and 1 mL N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 53%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0090] Comparative Example 3:

[0091] 11.2 mg KOH, 30 mg 1% Pd / MOR zeolite, 0.4 mmol styrene, 0.2 mmol phenylacetonitrile, and 1 mL N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 61%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0092] Comparative Example 4:

[0093] 11.2 mg KOH, 0.2 mmol potassium carbonate, 0.4 mmol styrene, 0.2 mmol phenylacetonitrile, and 1 mL N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion and selectivity were determined by GC. Almost no target product was formed.

[0094] Comparative Example 5:

[0095] 11.2 mg KOH, 0.2 mmol Pd(NO3)2, 0.4 mmol styrene, 0.2 mmol phenylacetonitrile, and 1 mL N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 45%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

[0096] Comparative Example 6:

[0097] 20 mg of triethylamine, 30 mg of 1% Pd / ETS-10, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The results showed that no target product was formed.

[0098] Comparative Example 7

[0099] 30 mg of 1% Pd / ETS-10, 0.4 mmol of styrene, 0.2 mmol of phenylacetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The results showed that no target product was formed.

[0100] Comparative Example 8

[0101] 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol phenylacetonitrile, and 1 mL N,N-dimethylformamide were added to a reaction tube. The reaction was carried out in a heater at 150 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and the conversion and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 42%. The reaction solution was then separated by column chromatography (using a mixture of cyclohexane and ethyl acetate as the eluent) after rotary evaporation to obtain the product.

Claims

1. A method for catalytic synthesis of α-alkylbutadiene nitrile compounds, characterized in that: A palladium-supported catalyst and KOH were added to a reaction vessel, followed by styrene compounds, phenylacetonitrile compounds, and a solvent. The reaction was carried out under a nitrogen atmosphere at 120-160 °C. The product was then centrifuged and rotary evaporated, and the resulting liquid product was separated by column chromatography to obtain α-alkylbutadiene nitrile compounds. ； R1 is derived from hydrogen, 2-methyl, 4-methyl, 3-fluoro, 4-fluoro, or 3-chloro substituents; R2 is derived from hydrogen, 4-methyl, 3-methyl, 4-methoxy, 4-chloro, or 2-fluoro substituents; the solvent is one of dimethyl sulfoxide or N,N-dimethylformamide; the catalyst supported on palladium metal is Pd / ETS-10.

2. The method for catalytic synthesis of α-alkylbutadiene nitrile compounds according to claim 1, characterized in that: The heating reaction time is 6~16 hours.

3. The method for catalytic synthesis of α-alkylbutadiene nitrile compounds according to claim 1, characterized in that: The molar ratio of phenylacetonitrile compounds to styrene compounds is 2:3 to 1:

4.

4. The method for catalytic synthesis of α-alkylbutadiene nitrile compounds according to claim 1, characterized in that: The molar ratio of phenylacetonitrile compounds to KOH is 2:1 to 1:

2.

5. The method for catalytic synthesis of α-alkylbutadiene nitrile compounds according to claim 1, characterized in that: The palladium loading in the catalyst is 1% to 7% by mass.

6. The method for catalytic synthesis of α-alkylbutadiene nitrile compounds according to claim 1, characterized in that: The molar ratio of phenylacetonitrile compounds to the mass ratio of Pd / ETS-10 is 1:100~1:200 mol / g.

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