Method for catalytically synthesizing alpha alkyl butyronitrile compound

Abstract

The invention belongs to the technical field of organic synthetic chemistry, and discloses a method for catalytically synthesizing an alpha-alkyl butyronitrile compound, which comprises the following steps: by taking a styrene compound and a phenylacetonitrile compound as substrates, carrying out catalytic reaction at 120-160 DEG C for 6-16 hours in a nitrogen atmosphere under the combined action of a palladium catalyst and KOH to obtain the alpha-alkyl butyronitrile compound. According to the method, alpha alkylation of phenylacetonitrile is achieved under the conditions that complex metal complexes do not need to be added to serve as catalysts and excessive alkylation substrates are not needed, and the catalysts can be repeatedly used and are good in stability and mild in reaction.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthetic chemistry, and particularly relates to a method for synthesizing alpha-alkyl butyronitrile by taking styrene and benzyl cyanide as substrates under the action of a Pd / ETS-10 catalyst. Background Art

[0002] Nitriles are important functional groups that are ubiquitous in natural products, agrochemicals, drugs, and polymers. Among them, α-alkylnitriles are unique structural units in organic synthesis and bioactive molecules. They are universal precursors for the synthesis of a variety of compounds, such as aldehydes, ketones, carboxylic acids, esters, amides, and amines, and have multiple functions. Therefore, the development of novel and efficient synthetic methods to prepare selectively synthesized α-alkylnitriles is very important for both organic chemistry and medicinal chemistry. Among the various strategies developed for the preparation of alkylnitriles, transition metal-catalyzed hydrogen transfer reactions using phenylethanol and phenylacetonitrile as raw materials are a direct and effective method. However, these methods rely heavily 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). In addition, although Wu Guojiao and his colleagues used the deamination coupling of α-aminoacetonitrile and arylboronic acid to achieve the alkylation of nitrile (Angew.Chem.Int.Ed.2014,53,10510-10514). And Ross used cyaniding reagent to achieve the alkylation of nitrile under the catalysis of metal nickel (Eur.J.Org.Chem.2023,26,e202300050). However, in these schemes, the catalysis of metal complexes is generally required, and organic ligands are added, resulting in the complexity of catalyst separation and product purification. Not only that, the above method requires excessive alkylation substrate to achieve high yield, and the atom economy is poor. The above problems seriously hinder the further application of the pharmaceutical industry and industrial field.

[0003] Therefore, it is urgent to develop a simple, efficient and mild catalytic system for the synthesis of α-alkyl nitrile. Based on this, the present invention innovatively develops a heterogeneous catalytic system: using metal-supported ETS-10 as a catalyst to catalyze the α-alkylation of benzyl cyanide. Compared with other routes, this method greatly improves the yield of α-alkyl nitrile compounds under the premise of environmental protection. Summary of the invention

[0004] In the presence of Pd / ETS-10 catalyst, a 100% atom-economical α-alkylation synthesis was achieved using styrene compounds and benzyl cyanide compounds as substrates.

[0005] The characteristics of the present invention are: ① Pd / ETS-10 zeolite has good stability, can be recycled for many times, and has economic value; ② mild reaction conditions and high reaction efficiency; ③ 100% atomic economy.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] With styrene compounds and benzyl cyanide compounds as substrates, a set amount of Pd / ETS-10 catalyst and a base are added into a reaction tube, and then a certain amount of styrene compounds and benzyl cyanide compounds are added, and the reaction is carried out at a target reaction temperature under a nitrogen atmosphere, and then the generated product is centrifuged and rotary evaporated, and the obtained liquid product is separated by column chromatography to obtain pure α-alkyl butyronitrile.

[0008]

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

[0010] The reaction temperature in the present invention is 120-160°C, preferably 150°C.

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

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

[0013] Furthermore, the molar ratio of the benzyl cyanide compound to the styrene compound is 2:3 to 1:4, preferably 1:2.

[0014] The molar ratio of benzyl cyanide to KOH is 2:1 to 1:2, preferably 1:1.

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

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

[0017] Furthermore, the molar ratio of the benzyl cyanide compound to the mass ratio 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, and the target product can be efficiently synthesized without the need to add complex metal complexes as catalysts or excessive amounts of alkylation substrates.

[0020] (2) Pd / ETS-10 zeolite is easy to separate and recycle, can be reused many times, has good stability, and has economic value and industrial significance. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0025] Figure 5 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] Fig. 9 The 2-phenyl-4-(p-tolyl)butyronitrile obtained in Example 14 is 1 H-NMR spectrum.

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

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

[0032] In order to further understand the purpose, content and advantages of the present invention, the specific embodiments of the present invention are described in detail below, but they are not limited to the following examples, and the reaction conditions should be changed according to the actual situation. Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

[0033] The ETS-10 zeolite used in the examples was prepared according to the 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 and crystallized at 230° C. for 3 days. Filter, dry and calcine at 475° C. for 5 hours. The molar ratio of the reaction gel system is 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, prepare a palladium nitrate metal salt solution, add it dropwise into 1.0g of ETS-10 zeolite by an equal volume impregnation method, dry it at room temperature for 12h, place it in a 100℃ oven for 8h, and calcine it in a muffle furnace under air atmosphere. The calcination procedure is: heat from room temperature to 100℃ at a rate of 5℃·min-1, and then heat at a rate of 3℃·min-1. -1 The temperature was increased from 100°C to 450°C at a rate and maintained for 4 hours to obtain a 1% Pd / ETS-10 zeolite catalyst.

[0035] Embodiment 1:

[0036]

[0037] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, 1 mL N, N-dimethylformamide were added to the reaction tube, and the mixture was reacted in a 150°C heater for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and sampled, and the conversion rate and selectivity were determined by GC. The final calculated yield of 2,4-diphenylbutyronitrile was 89%. The reaction solution was rotary evaporated and separated by column chromatography (the eluting reagent was a mixture of cyclohexane and ethyl acetate) 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] Embodiment 2:

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

[0040] The solvent in Example 2 was replaced with 1 mL of toluene, and other conditions remained unchanged. The conversion rate and selectivity were measured 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 rate and selectivity were measured by GC, and the yield of the product was 0%.

[0042] Embodiment 3:

[0043] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 110°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2,4-diphenylbutyronitrile was 62%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

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

[0045] Embodiment 4:

[0046] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 8 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2,4-diphenylbutyronitrile was 64%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

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

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

[0049] Embodiment 5:

[0050] 30 mg 1% Pd / ETS-10 zeolite and 22.4 mg KOH, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2,4-diphenylbutyronitrile was 83%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

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

[0052] Embodiment 6:

[0053] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.4 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2,4-diphenylbutyronitrile was 75%. The reaction solution was rotary evaporated and separated by column chromatography (eluting reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

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

[0055] Embodiment 7:

[0056]

[0057] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol p-chlorophenylacetonitrile, 1 mL N, N-dimethylformamide were added to the reaction tube, and the mixture was reacted in a 150°C heater for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and sampled, and the conversion rate and selectivity were determined by GC. The final calculated yield of 2-(4-chlorophenyl)-4-phenylbutyronitrile was 74%. The reaction solution was rotary evaporated and separated by column chromatography (eluting reagent was a mixture of cyclohexane and ethyl acetate) 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] Embodiment 8:

[0059]

[0060] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol p-methoxyphenylacetonitrile, 1 mL N, N-dimethylformamide were added to the reaction tube, and the mixture was reacted in a 150°C heater for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and sampled, and the conversion rate and selectivity were determined using GC. The final calculated yield of 2-(4-methoxyphenyl)-4-phenylbutyronitrile was 84%. The reaction solution was rotary evaporated and then separated by column chromatography (eluting reagent was a mixture of cyclohexane and ethyl acetate) 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] Embodiment 9:

[0063]

[0064] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol p-methylphenylacetonitrile, 1 mL N, N-dimethylformamide were added to the reaction tube, and the mixture was reacted in a 150°C heater for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 4-phenyl-2-(p-tolyl)butyronitrile was 69%. The reaction solution was rotary evaporated and separated by column chromatography (the eluting reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product. The characterization data of the product are as follows: 1HNMR (400 MHz, Chloroform-d) δ7.31-7.12 (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] Embodiment 10:

[0066]

[0067] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol 2-fluorophenylacetonitrile, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2-(2-fluorophenyl)-4-phenylbutyronitrile was 69%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product. The characterization data of the product are as follows: 1H NMR (400 MHz, 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] Embodiment 11:

[0069]

[0070] 30 mg of 1% Pd / ETS-10 zeolite and 11.2 mg of KOH, 0.4 mmol of styrene, 0.2 mmol of m-methylbenzene acetonitrile, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 4-phenyl-2-(m-tolyl)butyronitrile was 68%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

[0071] Embodiment 12:

[0072]

[0073] 30 mg of 1% Pd / ETS-10 zeolite and 11.2 mg of KOH, 0.4 mmol of p-fluorostyrene, 0.2 mmol of benzyl cyanide, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 4-(4-fluorophenyl)-2-phenylbutyronitrile was 71%. The reaction solution was rotary evaporated and separated by column chromatography (the eluting reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

[0074] Embodiment 13:

[0075]

[0076] 30 mg of 1% Pd / ETS-10 zeolite and 11.2 mg of KOH, 0.4 mmol of m-fluorostyrene, 0.2 mmol of benzyl cyanide, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 4-(3-fluorophenyl)-2-phenylbutyronitrile was 79%. The reaction solution was rotary evaporated and separated by column chromatography (the eluting reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

[0077] Embodiment 14:

[0078]

[0079] 30 mg of 1% Pd / ETS-10 zeolite and 11.2 mg of KOH, 0.4 mmol of p-methylstyrene, 0.2 mmol of benzyl cyanide, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2-phenyl-4-(p-tolyl)butyronitrile was 70%. The reaction solution was rotary evaporated and separated by column chromatography (eluting reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product. The characterization data of the product are as follows: 1H NMR (400 MHz, 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] Embodiment 15:

[0081]

[0082] 30 mg of 1% Pd / ETS-10 zeolite and 11.2 mg of KOH, 0.4 mmol of m-chlorostyrene, 0.2 mmol of benzyl cyanide, and 1 mL of N,N-dimethylformamide were added to a reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 4-(3-chlorophenyl)-2-phenylbutyronitrile was 75%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

[0083] Embodiment 16:

[0084]

[0085] 30 mg 1% Pd / ETS-10 zeolite and 11.2 mg KOH, 0.4 mmol o-methylstyrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The final calculated yield of 2-phenyl-4-(o-tolyl)butyronitrile was 68%. The reaction solution was rotary evaporated and separated by column chromatography (eluting reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

[0086] Comparative Example 1:

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

[0088] Comparative Example 2:

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

[0090] Comparative Example 3:

[0091] 11.2 mg KOH and 30 mg 1% Pd / MOR zeolite, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to a reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 61%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) 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 benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC, and almost no target product was generated.

[0094] Comparative Example 5:

[0095] 11.2 mg KOH, 0.2 mmol Pd(NO3)2, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 45%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) 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 benzyl cyanide, and 1 mL of N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. As a result, no target product was produced.

[0098] Comparative Example 7

[0099] 30 mg of 1% Pd / ETS-10, 0.4 mmol of styrene, 0.2 mmol of benzyl cyanide, and 1 mL of N,N-dimethylformamide were added to the reaction tube. The mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC, and no target product was produced.

[0100] Comparative Example 8

[0101] 11.2 mg KOH, 0.4 mmol styrene, 0.2 mmol benzyl cyanide, and 1 mL N,N-dimethylformamide were added to the reaction tube, and the mixture was reacted in a 150°C heater under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was centrifuged and sampled. The conversion rate and selectivity were determined by GC. The yield of 2,4-diphenylbutyronitrile was calculated to be 42%. The reaction solution was rotary evaporated and separated by column chromatography (the elution reagent was a mixture of cyclohexane and ethyl acetate) to obtain the product.

Claims

1. A method for catalytically synthesizing α-alkyl butyronitrile compounds, characterized in that: Adding a palladium metal-loaded catalyst and KOH into a reaction container, then adding a styrene compound, a benzyl cyanide compound and a solvent, heating the reaction at 120-160° C. under a nitrogen atmosphere, and then subjecting the reaction product to centrifugation and rotary evaporation, and then subjecting the obtained liquid product to column chromatography separation to obtain an α-alkyl butyronitrile compound; 2. The method for catalytically synthesizing α-alkyl butyronitrile compounds according to claim 1, characterized in that: R1 is selected from hydrogen, 2-methyl, 4-methyl, 3-fluoro, 4-fluoro or 3-chloro substituents; R2 is selected from hydrogen, 4-methyl, 3-methyl, 4-methoxy, 4-chloro or 2-fluoro substituents.

3. The method for catalytic synthesis of α-alkyl butyronitrile compounds according to claim 1, characterized in that: The heating reaction time is 6 to 16 hours.

4. The method for catalytically synthesizing α-alkyl butyronitrile compounds according to claim 1, characterized in that: The solvent is one of dimethyl sulfoxide and N,N-dimethylformamide.

5. The method for catalytic synthesis of α-alkyl butyronitrile compounds according to claim 1, characterized in that: The molar ratio of the benzyl cyanide compound to the styrene compound is 2:3 to 1:

4.

6. The method for catalytically synthesizing α-alkyl butyronitrile compounds according to claim 1, characterized in that: The molar ratio of the benzyl cyanide compound to KOH is 2:1 to 1:

2.

7. The method for catalytically synthesizing α-alkyl butyronitrile compounds according to claim 1, characterized in that: The catalyst loaded with palladium metal is Pd / ETS-10; the loading mass of palladium is 1% to 7%.

8. The method for catalytic synthesis of α-alkyl butyronitrile compounds according to claim 1, characterized in that: The molar amount of the benzyl cyanide compound and the mass ratio of the Pd / ETS-10 zeolite are 1:100 to 1:200 mol / g.

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