A method for preparing chogel analogs by photocatalytic dimerization reaction

Abstract

The application discloses a preparation method of azirin analogs. The preparation method is as follows: taking 2-vinylaniline compounds as starting materials, directly irradiating under 350nm-380nm light, or taking 9-thioxanthone as a photocatalyst, irradiating under 380nm-410nm blue-violet light, and reacting the starting materials in an organic solvent to obtain azirin analogs through purification. The azirin analogs can be efficiently prepared in one step. The reaction condition is mild, the process is simple, the operation is convenient, the photocatalyst and the starting materials are cheap and easy to obtain, the obtained product can be used as a skeleton of a catalyst, and various new catalysts or ligands can be developed, which has important significance for the research and development of catalysts.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic synthesis, and particularly relates to a method for preparing a choge base analogue through a photochemical dimerization reaction of 2-vinylaniline under photocatalysis. BACKGROUND

[0002] Choge base and its derivatives (a) are a class of unique compounds with rigid molecular structure and a C2 symmetry axis, and the whole molecule presents a V-shaped twisted configuration, and has a hydrophobic cavity. In recent decades, choge base and its derivatives have become a research hotspot, and have played an important role in the field of supramolecular chemistry, such as molecular biomimetic receptor, molecular recognition, DNA probe, metal organic framework material and membrane material (Helvetica Chimica Acta, 2009, 92, 415).

[0003]

[0004] In the field of asymmetric catalysis, choge base and its derivatives also have a wide range of applications, and are often used as chiral structural framework to develop a series of powerful chiral small molecule catalysts or chiral ligands, such as compounds (b) and (c) as organic small molecule catalysts to realize a variety of important organic chemical transformations; compounds (d) and (e) can be used as chiral ligands to participate in a variety of metal organic catalytic reactions (Helvetica Chimica Acta, 2009, 92, 415; Chin. J. Org. Chem. 2020, 40, 988).

[0005] The synthesis method of choge base and its derivatives has attracted widespread attention, and a large number of synthesis methods have been reported. The traditional method needs to use strong corrosive acid catalyst, formaldehyde raw material and high temperature reaction condition, and has certain limitations. Therefore, the demand for green and sustainable chemistry requires the development of a mild, efficient, non-toxic and environmentally friendly synthesis method. SUMMARY

[0006] The purpose of the present application is to provide a simple and efficient method for preparing choge base analogue, which has mild reaction conditions, simple process and convenient operation. The specific reaction equation is as follows.

[0007]

[0008] The preparation method is to use 2-vinylaniline compound of formula (I) as starting material, directly under the condition of near ultraviolet light irradiation at 350nm-380nm (because the starting material 2-vinylaniline compound can be directly excited and then undergo subsequent chemical conversion under the condition of light irradiation at this wavelength), or use 9-thioxanthone as photocatalyst, under the condition of blue-violet light irradiation at 380nm-410nm (because the photocatalyst 9-thioxanthone is only excited under the condition of blue-violet light irradiation at 380-410nm to play a catalytic role), the starting material is reacted in an organic solvent, and the azomethine analogue of formula (II) is obtained by purification;

[0009] R in formula (I) and (II) 1 ~R 5 are the same, and R 1 ~R 5 is selected from any one of H, C1-C4 alkyl, C1-C4 alkoxy, trifluoromethyl, hydroxymethyl, trifluoromethoxy, halogen, pinacol borate group;

[0010] The photocatalyst 9-thioxanthone has the following formula (III):

[0011]

[0012] Preferably, the 2-vinylaniline compound is:

[0013]

[0014] Preferably, the azomethine analogue is preferably:

[0015]

[0016]

[0017] Preferably, the organic solvent is acetonitrile. When acetonitrile is used as the solvent, the reaction can smoothly occur and the highest yield is obtained; when any one of toluene, 1,2-dichloroethane, N,N-dimethylformamide is used as the solvent, the reaction does not occur; when any one of ethyl acetate, tetrahydrofuran, dimethyl sulfoxide is used as the solvent, the reaction occurs, but the yield is low. Therefore, the optimal solvent is acetonitrile.

[0018] Preferably, the molar ratio of the photocatalyst 9-thioxanthone and the 2-vinylaniline compound is 1: (2-100), and more preferably, the molar ratio of the two is 1:10. When the molar ratio of the photocatalyst 9-thioxanthone and the 2-vinylaniline compound is 1:2, the reaction occurs, but the yield is moderate; when the molar ratio is 1:100, the reaction occurs, but the yield is only 65%; when the molar ratio is 1:10, the reaction occurs smoothly, and the product is obtained at a highest yield of 83%. Therefore, the molar ratio of the two is preferably 1:10.

[0019] Preferably, the reaction time is 16 hours, the reaction temperature is room temperature, and the reaction is carried out in an inert gas atmosphere. Under the reaction time and temperature conditions, the starting material 2-vinylaniline compound can be completely converted; when the reaction is carried out in an atmospheric atmosphere, side reactions occur, resulting in a decrease in the yield of the reaction, so the reaction needs to be carried out in an inert gas atmosphere.

[0020] Preferably, after the reaction is completed, the separation of the final product and the recovery of the catalyst are completed by column chromatography, and the eluent of the column chromatography is a mixed solvent of ethyl acetate / petroleum ether, and more preferably, the volume ratio of ethyl acetate / petroleum ether is 1:10-20.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1) In the present application, under the conditions of light or light and photocatalyst catalysis, the reaction is carried out by a single component of 2-vinylaniline compound, and the chrysin analogue can be efficiently prepared in one step, with high atom economy and high yield.

[0023] 2) The reaction conditions of the present application are mild, the operation is simple, and the industrialization is easy.

[0024] 3) The present application is green and pollution-free, does not need metal catalysis, the reaction raw materials and catalysts are clean and non-toxic, and the environmental pollution is small.

[0025] 4) The 2-vinylaniline compound used in the present application can be easily prepared from aniline and its derivatives, and the raw materials are very widely available and inexpensive, which reduces the preparation cost of the final product.

[0026] 5) The present application has wide application range and high practicability, the product chrysin analogue can be used as the skeleton of the catalyst to develop various new catalysts or ligands, and has potential synthetic application value. DETAILED DESCRIPTION

[0027] The following examples will help to understand the present application, but are not limited to the content of the present application.

[0028] Example 1

[0029] A reaction vial was charged with the 2-vinylaniline compound of the preceding structural formula (I-1) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, and the reaction was carried out under argon (1 atm) at room temperature under irradiation (λ = 380-410 nm) for 16 hours. After the reaction was completed, the product was directly purified by silica gel column chromatography with ethyl acetate / petroleum ether = 1:10 as the eluent to obtain the corresponding azomethine analogue. The product was a white solid with a yield of 77%; the product was characterized as follows:

[0030] Structural formula:

[0031]

[0032] 1 H NMR (600 MHz, CDC13) δ 7.28 (d, J = 7.8 Hz, 2H), 7.22-7.16 (m, 6H), 7.12 (dd, J = 7.6, 1.4 Hz, 2H), 7.10-7.06 (m, 4H), 7.03-6.99 (m, 4H), 4.00 (s, 2H), 1.92 (s, 6H).

[0033] 13 C NMR (151 MHz, CDC13) δ 148.9, 145.0, 141.2, 128.1, 128.1, 127.8, 127.8, 126.4, 125.7, 124.6, 65.6, 33.1.

[0034] HRMS (ESI) m / z: [M + H] + Calcd for C 28 H 22 N2 + 391.2169, Found 391.2178.

[0035] Single crystal structure:

[0036]

[0037] Example 2

[0038] A reaction vial was charged with the 2-vinylaniline compound of the preceding structural formula (I-2) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, and the reaction was carried out under argon (1 atm) at room temperature under irradiation (λ = 380-410 nm) for 16 hours. After the reaction was completed, the product was directly purified by silica gel column chromatography with ethyl acetate / petroleum ether = 1:10 as the eluent to obtain the corresponding azomethine analogue. The product was a white solid with a yield of 74%; the product was characterized as follows:

[0039] Structure:

[0040]

[0041] 1 H NMR (500 MHz, CDC13) δ 7.21 - 7.13 (m, 8H), 7.11 - 7.07 (m, 4H), 6.86 - 6.80 (m, 4H), 3.94 (s, 2H), 2.24 (s, 6H), 1.90 (s, 6H).

[0042] 13 C NMR (126 MHz, CDC13) δ 149.1, 144.8, 138.0, 137.3, 128.9, 128.0, 127.6, 126.2, 125.7, 125.2, 65.3, 33.0, 20.9.

[0043] HRMS (ESI) m / z: [M+H] + Calcd for C 30 H 31 N2 + 419.2482, Found 419.2498.

[0044] Example 3

[0045] A reaction vial was charged with the 2-vinylaniline compound of the preceding structure (I-3) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structure (III) (0.04 mmol), and 4 mL of acetonitrile. The reaction vial was purged with argon (1 atm) and irradiated (λ = 380-410 nm) at room temperature for 24 h. The reaction mixture was directly purified by silica gel column chromatography with ethyl acetate / petroleum ether = 1:10 as eluent to give the corresponding azomethine analogue as a white solid in 32% yield. The product was characterized as follows:

[0046] Structure:

[0047]

[0048] 1 H NMR (500 MHz, CDC13) δ 7.43 (s, 1H), 7.41 (s, 1H), 7.32 (s, 1H), 7.31 (s, 1H), 7.27 - 7.21 (m, 8H), 7.06 - 7.02 (m, 4H), 4.09 (s, 2H), 1.96 (s, 6H).

[0049] 13C NMR (126 MHz, CDCI3) δ 147.3, 145.3, 144.9, 130.3 (d, J = 32.6 Hz), 128.4, 128.4, 126.9, 125.5, 124.9 (d, J = 3.4 Hz), 121.7 (d, J = 3.9 Hz), 65.8, 33.0.

[0050] 19 F NMR (565 MHz, CDCI3) δ -62.58.

[0051] HRMS (ESI) m / z: [M + H]+Calcd for C + H 30 F6N2 25 F6N2 + 527.1916, Found 527.1923.

[0052] Example 4

[0053] In a reaction flask, 2-vinylaniline compound (0.4 mmol) shown in the above structural formula (I-4), photocatalyst 9-thioxanthone (0.04 mmol) shown in the above structural formula (III) were added, 4 mL of acetonitrile was injected, under argon (1 atm), under light (λ = 380-410 nm), at room temperature, the reaction was carried out for 16 hours, after the reaction was completed, direct silica gel column chromatography was carried out, eluent was ethyl acetate / petroleum ether = 1:10, the corresponding azomethine analogue was obtained, the product was a white solid, the yield was 68%; the product was characterized as follows:

[0054] Structural formula:

[0055]

[0056] 1 H NMR (500 MHz, CDCI3) δ 7.22 - 7.13 (m, 6H), 7.12 - 7.04 (m, 6H), 6.95 - 6.87 (m, 4H), 3.95 (s, 2H), 2.25 (s, 6H), 1.90 (s, 6H).

[0057] 13 C NMR (126 MHz, CDCI3) δ 149.0, 142.2, 140.9, 133.6, 128.6, 128.2, 128.0, 127.9, 126.2, 125.7, 65.4, 32.9, 21.3.

[0058] HRMS (ESI) m / z: [M + H]+Calcd for C 30 H 31 N2+ 419.2482, Found 419.2496.

[0059] Example 5

[0060] Into a reaction vial was added the 2-vinylaniline compound of the preceding structural formula (I-5) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), the reaction was irradiated (λ = 380-410 nm) at room temperature for 16 hours, after the reaction was completed, it was directly purified by silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:10, to give the corresponding azomethine analogue, the product was a white solid, yield 60%; the product was characterized as follows:

[0061] Structural formula:

[0062]

[0063] 1 H NMR (500 MHz, CDC13) δ 7.25 - 7.20 (m, 6H), 7.12 (s, 2H), 7.07 - 7.00 (m, 8H), 3.94 (s, 2H), 1.88 (s, 6H).

[0064] 13 C NMR (126 MHz, CDC13) δ 147.5, 146.0, 143.4, 143.0, 129.0, 128.4, 126.9, 125.5, 121.5, 121.0, 120.2, 119.4, 65.5, 32.8.

[0065] 19 F NMR (565 MHz, CDC13) δ -58.07.

[0066] HRMS (ESI) m / z: [M + H] + Calcd for C 30 H 25 F6N2O2 + 559.1815, Found 559.1827.

[0067] Example 6

[0068] A reaction vial was charged with the 2-vinylaniline compound of the preceding structural formula (I-6) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), under irradiation (λ = 380-410 nm), at room temperature for 16 hours. After the reaction was completed, direct silica gel column chromatography was used with ethyl acetate / petroleum ether = 1 :20 as the eluent to obtain the corresponding azomethine analogue. The product was a white solid with a yield of 68%; the product was characterized as follows:

[0069] Structural formula:

[0070]

[0071] 1 H NMR (500 MHz, CDC13) δ 7.25 (d, J = 2.6 Hz, 2H), 7.24 - 7.18 (m, 6H), 7.13 (d, J = 2.4 Hz, 1H), 7.12 (d, J = 2.4 Hz, 1H), 7.08 - 7.03 (m, 4H), 6.95 (s, 1H), 6.93 (s, 1H), 3.92 (s, 2H), 1.87 (s, 6H).

[0072] 13 C NMR (126 MHz, CDC13) δ 147.7, 143.3, 142.9, 130.1, 129.3, 128.3, 128.1, 126.7, 125.5, 65.5, 32.8.

[0073] HRMS (ESI) m / z: [M + H] + Calcd for C 28 H 25 Cl2N2 + 459.1389, Found 459.1397.

[0074] Example 7

[0075] A reaction vial was charged with the 2-vinylaniline compound of the preceding structural formula (I-7) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), under irradiation (λ = 380-410 nm), at room temperature for 24 hours. After the reaction was completed, direct silica gel column chromatography was used with ethyl acetate / petroleum ether = 1 :10 as the eluent to obtain the corresponding azomethine analogue. The product was a white solid with a yield of 46%; the product was characterized as follows:

[0076] Structural formula:

[0077]

[0078] 1 H NMR (500 MHz, CDC13) δ 7.39 (d, J = 2.3 Hz, 2H), 7.28 (d, J = 2.3 Hz, 1H), 7.27 (d, J = 2.3 Hz, 1H), 7.24 - 7.18 (m, 6H), 7.07 - 6.98 (m, 4H), 6.89 (s, 1H), 6.87 (s, 1H), 3.92 (s, 2H), 1.87 (s, 6H).

[0079] 13 C NMR (126 MHz, CDC13) δ 147.6, 143.8, 143.3, 131.1, 130.9, 129.8, 128.3, 126.8, 125.5, 118.2, 65.5, 32.8.

[0080] HRMS (ESI) m / z: [M + H] + Calcd for C 28 H 25 Br2N2+ 547.0379, Found 547.0391.

[0081] Example 8

[0082] A reaction vial was charged with the 2-vinylaniline compound of the preceding structural formula (I-8) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), and 4 mL of acetonitrile. The reaction vial was purged with argon (1 atm) and irradiated (λ = 380-410 nm) at room temperature for 16 h. The reaction mixture was directly purified by silica gel column chromatography using ethyl acetate / petroleum ether = 1 : 10 as eluent to give the corresponding azomethine analogue as a white solid in 78% yield. The product was characterized as follows:

[0083] Structural formula:

[0084]

[0085] 1 H NMR (500 MHz, CDC13) δ 7.27 (dd, J = 7.7, 1.3 Hz, 2H), 7.14 - 7.06 (m, 4H), 7.03 - 6.96 (m, 8H), 6.80 (d, J = 7.8 Hz, 2H), 4.00 (s, 2H), 2.24 (s, 6H), 1.92 (s, 6H).

[0086] 13C NMR (126 MHz, CDC13) δ 148.7, 145.0, 141.3, 137.7, 128.0, 127.9, 127.8, 127.6, 127.1, 126.2, 124.5, 123.0, 77.3, 77.0, 76.8, 65.5, 33.1, 21.6.

[0087] HRMS (ESI) m / z: [M + H] + Calcd for C 30 H 31 N2 + 419.2482, Found 419.2496.

[0088] Example 9

[0089] Into a reaction vial was added the 2-vinylaniline compound of the preceding structural formula (I-9) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), and 4 mL of acetonitrile. The reaction vial was purged with argon (1 atm) and irradiated (λ = 380-410 nm) at room temperature for 16 hours. The reaction mixture was directly purified by silica gel column chromatography using ethyl acetate / petroleum ether = 1:10 as the eluent to give the corresponding azomethine analogue as a white solid in 80% yield. The product was characterized as follows:

[0090] Structural formula:

[0091]

[0092] 1 H NMR (500 MHz, CDC13) δ 7.27 (d, J = 1.3 Hz, 1H), 7.25 (s, 1H), 7.22-7.11 (m, 4H), 7.07-6.98 (m, 4H), 6.92-6.82 (m, 4H), 6.78 (t, J = 2.1 Hz, 1H), 6.77-6.75 (m, 1H), 3.93 (s, 2H), 1.91 (s, 6H).

[0093] 13 C NMR (126 MHz, CDC13) δ 163.7, 161.8, 151.7 (d, J = 6.4 Hz), 144.6, 140.5, 129.6 (d, J = 8.0 Hz), 128.1 (d, J = 10.6 Hz), 127.7, 124.9, 121.3 (d, J = 2.8 Hz), 113.3 (d, J = 21.4 Hz), 112.9 (d, J = 23.0 Hz), 65.4 (d, J = 1.6 Hz), 32.8.

[0094] 19 F NMR (565 MHz, CDC13) δ -113.12.

[0095] HRMS (ESI) m / z: [M+H] + Calcd for C 28 H 25 F2N2 + 427.1980, Found 427.1992.

[0096] Example 10

[0097] A reaction vial was charged with the 2-vinylaniline compound of the preceding structural formula (I-10) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), and 4 mL of acetonitrile. The reaction vial was purged with argon (1 atm) and irradiated (λ = 380-410 nm) at room temperature for 16 h. After the reaction was completed, the reaction mixture was directly purified by silica gel column chromatography with ethyl acetate / petroleum ether = 1 : 10 as eluent to give the corresponding azomethine analogue as a white solid in 85% yield. The product was characterized as follows:

[0098] Structural formula:

[0099]

[0100] 1 H NMR (500 MHz, CDC13) δ 7.26 (dd, J = 7.6, 1.4 Hz, 2H), 7.14 (td, J = 7.5, 1.4 Hz, 2H), 7.06 - 6.99 (m, 8H), 6.91 - 6.86 (m, 4H), 3.92 (s, 2H), 1.90 (s, 6H).

[0101] 13 C NMR (126 MHz, CDC13) δ 162.4, 160.4, 144.8, 144.7 (d, J = 3.2 Hz), 140.8, 128.1 (d, J = 3.2 Hz), 127.7, 127.4, 127.3 (d, J = 7.8 Hz), 124.7, 114.8 (d, J = 21.1 Hz), 65.2, 33.0.

[0102] 19 F NMR (565 MHz, CDC13) δ -116.99.

[0103] HRMS (ESI) m / z: [M+H] + Calcd for C 28 H 25F2N2 + 427.1980, Found 427.1993.

[0104] Example 11

[0105] Into a reaction vial was added the 2-vinylaniline compound of the preceding structural formula (I-11) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), the reaction was irradiated (λ = 380-410 nm) at room temperature for 16 hours, after the reaction was completed, it was directly purified by silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:20, to give the corresponding azomethine analogue, the product was a white solid, yield 61%; the product was characterized as follows:

[0106] Structural formula:

[0107]

[0108] 1 H NMR (500 MHz, CDC13) δ 7.25 (dd, J = 7.8, 1.4 Hz, 2H), 7.20 - 7.16 (m, 4H), 7.14 (td, J = 7.6, 1.4 Hz, 2H), 7.04 - 6.97 (m, 8H), 3.90 (s, 2H), 1.89 (s, 6H).

[0109] 13 C NMR (126 MHz, CDC13) δ 147.5, 144.7, 140.5, 132.2, 128.2, 128.1, 128.1, 127.7, 127.2, 124.8, 65.3, 32.8.

[0110] HRMS (ESI) m / z: [M + H] + Calcd for C 28 H 25 Cl2N2 + 459.1389, Found 459.1395.

[0111] Example 12

[0112] A reaction vial was charged with the 2-vinylaniline compound of the previous structural formula (I-12) (0.4 mmol), the photocatalyst 9-thioxanthone of the previous structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), under irradiation (λ = 380-410 nm) at room temperature for 16 hours, after the reaction was completed, it was directly used for silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:10, the corresponding azomethine analogue was obtained, the product was a white solid, the yield was 76%; the product was characterized as follows:

[0113] Structural formula:

[0114]

[0115] 1 H NMR (500 MHz, CDCI3) δ 7.26 (d, J = 8.0 Hz, 2H), 7.11 (t, J = 7.5 Hz, 2H), 7.04-6.98 (m, 8H), 6.77-6.72 (m, 4H), 4.02 (s, 2H), 3.77 (s, 6H), 1.91 (s, 6H).

[0116] 13 C NMR (126 MHz, CDCI3) δ 158.0, 145.0, 141.3, 141.1, 128.1, 127.7, 127.6, 126.8, 124.5, 113.4, 65.2, 55.2, 33.1.

[0117] HRMS (ESI) m / z: [M + H] + Calcd for C 30 H 31 N2O2 + 451.2380, Found 451.2392.

[0118] Example 13

[0119] A reaction vial was charged with the 2-vinylaniline compound of the previous structural formula (I-12) (0.4 mmol), the photocatalyst 9-thioxanthone of the previous structural formula (III) (0.04 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), under irradiation (λ = 380-410 nm) at room temperature for 16 hours, after the reaction was completed, it was directly used for silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:10, the corresponding azomethine analogue was obtained, the product was a white solid, the yield was 76%; the product was characterized as follows:

[0120] Structural formula:

[0121]

[0122] 1 H NMR (500 MHz, CDC13) δ 7.29 - 7.25 (m, 2H), 7.16 - 7.09 (m, 6H), 7.07 - 7.01 (m, 8H), 4.46 (s, 4H), 4.25 (s, 2H), 3.09 (s, 2H), 1.90 (s, 6H).

[0123] 13 C NMR (126 MHz, CDC13) δ 147.7, 144.3, 140.8, 139.3, 128.1, 128.0, 127.7, 126.7, 125.8, 124.9, 65.7, 64.4, 32.5.

[0124] HRMS (ESI) m / z: [M+H] + Calcd for C 30 H 31 N2O2 + 451.2380, Found 451.2395.

[0125] Example 14

[0126] Into a reaction vial was placed the 2-vinylaniline compound of the preceding structural formula (I-14) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.04 mmol), and 4 mL of acetonitrile was injected. The reaction vial was purged with argon (1 atm) and irradiated (λ = 380-410 nm) at room temperature for 16 h. After the reaction was completed, the reaction mixture was directly purified by silica gel column chromatography using ethyl acetate / petroleum ether = 1 :20 as eluent to give the corresponding azomethine analogue as a white solid in 62% yield. The product was characterized as follows:

[0127] Structural formula:

[0128]

[0129] 1 H NMR (500 MHz, CDC13) δ 7.68 (d, J = 8.2 Hz, 4H), 7.27 (dd, J = 7.8, 1.2 Hz, 2H), 7.16 - 7.09 (m, 6H), 7.06 - 7.00 (m, 2H), 6.98 (d, J = 7.6 Hz, 2H), 4.01 (s, 2H), 1.90 (s, 6H), 1.35 (s, 12H), 1.34 (s, 12H).

[0130] 13C NMR (126 MHz, CDCI3) δ 152.0, 144.9, 141.1, 134.8, 128.1, 127.8, 127.7, 125.1, 124.6, 83.7, 65.8, 32.8, 25.0, 24.8.

[0131] HRMS (ESI) m / z: [M+H] + Calcd for C 40 H 49 N2O4 + 643.3873, Found 643.3887.

[0132] Example 15

[0133] Into a reaction vial was added the 2-vinylaniline compound of the preceding structural formula (I-1) (0.4 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), the reaction was carried out at room temperature under light (λ = 350-380 nm) for 16 hours, after the reaction was completed, it was directly purified by silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1 : 10, the corresponding azomethine analogue was obtained, the product was a white solid, yield 72%; the product was characterized as follows:

[0134] Structural formula:

[0135]

[0136] 1 H NMR (600 MHz, CDCI3) δ 7.28 (d, J = 7.8 Hz, 2H), 7.22 - 7.16 (m, 6H), 7.12 (dd, J = 7.6, 1.4 Hz, 2H), 7.10 - 7.06 (m, 4H), 7.03 - 6.99 (m, 4H), 4.00 (s, 2H), 1.92 (s, 6H).

[0137] 13 C NMR (151 MHz, CDCI3) δ 148.9, 145.0, 141.2, 128.1, 128.1, 127.8, 127.8, 126.4, 125.7, 124.6, 65.6, 33.1.

[0138] HRMS (ESI) m / z: [M+H] + Calcd for C 28 H 22 N2 + 391.2169, Found 391.2178.

[0139] Example 16

[0140] A reaction vial was charged with the 2-vinylaniline compound of the previous structural formula (I-2) (0.4 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), under light (λ = 350-380 nm) at room temperature for 16 hours, after the reaction was completed, directly using silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:10, the corresponding azomethine analogue was obtained, the product was a white solid, yield 75%; the product was characterized as follows:

[0141] Structural formula:

[0142]

[0143] 1 H NMR (500 MHz, CDC13) δ 7.21 - 7.13 (m, 8H), 7.11 - 7.07 (m, 4H), 6.86 - 6.80 (m, 4H), 3.94 (s, 2H), 2.24 (s, 6H), 1.90 (s, 6H).

[0144] 13 C NMR (126 MHz, CDC13) δ 149.1, 144.8, 138.0, 137.3, 128.9, 128.0, 127.6, 126.2, 125.7, 125.2, 65.3, 33.0, 20.9.

[0145] HRMS (ESI) m / z: [M+H] + Calcd for C 30 H 31 N2 + 419.2482, Found 419.2498.

[0146] Example 17

[0147] A reaction vial was charged with the 2-vinylaniline compound of the previous structural formula (I-10) (0.4 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), under light (λ = 350-380 nm) at room temperature for 16 hours, after the reaction was completed, directly using silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:10, the corresponding azomethine analogue was obtained, the product was a white solid, yield 81%; the product was characterized as follows:

[0148] Structural formula:

[0149]

[0150] 1H NMR (500 MHz, CDC13) δ 7.26 (dd, J = 7.6, 1.4 Hz, 2H), 7.14 (td, J = 7.5, 1.4 Hz, 2H), 7.06 - 6.99 (m, 8H), 6.91 - 6.86 (m, 4H), 3.92 (s, 2H), 1.90 (s, 6H).

[0151] 13 C NMR (126 MHz, CDC13) δ 162.4, 160.4, 144.8, 144.7 (d, J = 3.2 Hz), 140.8, 128.1 (d, J = 3.2 Hz), 127.7, 127.4, 127.3 (d, J = 7.8 Hz), 124.7, 114.8 (d, J = 21.1 Hz), 65.2, 33.0.

[0152] 19 F NMR (565 MHz, CDC13) δ -116.99.

[0153] HRMS (ESI) m / z: [M + H] + Calcd for C 28 H 25 F2N2 + 427.1980, Found 427.1993.

[0154] Example 18

[0155] Into a reaction vial was added the 2-vinylaniline compound of the preceding structural formula (I-1) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.2 mmol), 4 mL of acetonitrile was injected, under argon (1 atm), irradiation (λ = 380-410 nm) at room temperature for 16 hours, after the reaction was completed, directly using silica gel column chromatography, eluent was ethyl acetate / petroleum ether = 1:10, to obtain the corresponding azomethine analog, the product was a white solid, yield 58%; the product was characterized as follows:

[0156] Structural formula:

[0157]

[0158] 1 H NMR (600 MHz, CDC13) δ 7.28 (d, J = 7.8 Hz, 2H), 7.22 - 7.16 (m, 6H), 7.12 (dd, J = 7.6, 1.4 Hz, 2H), 7.10 - 7.06 (m, 4H), 7.03 - 6.99 (m, 4H), 4.00 (s, 2H), 1.92 (s, 6H).

[0159] 13 C NMR (151 MHz, CDC13) δ 148.9, 145.0, 141.2, 128.1, 128.1, 127.8, 127.8, 126.4, 125.7, 124.6, 65.6, 33.1.

[0160] HRMS (ESI) m / z: [M+H] + Calcd for C 28 H 22 N2 + 391.2169, Found 391.2178.

[0161] Example 19

[0162] Into a reaction vial was placed the 2-vinylaniline compound of the preceding structural formula (I-1) (0.4 mmol), the photocatalyst 9-thioxanthone of the preceding structural formula (III) (0.004 mmol), and 4 mL of acetonitrile was injected. The reaction was carried out under argon (1 atm) at room temperature for 16 hours under irradiation (λ = 380-410 nm). After the reaction was completed, the reaction mixture was directly purified by silica gel column chromatography using ethyl acetate / petroleum ether = 1:10 as the eluent to give the corresponding azomethine analogue as a white solid in 65% yield. The product was characterized as follows:

[0163] Structural formula:

[0164]

[0165] 1 H NMR (600 MHz, CDC13) δ 7.28 (d, J = 7.8 Hz, 2H), 7.22-7.16 (m, 6H), 7.12 (dd, J = 7.6, 1.4 Hz, 2H), 7.10-7.06 (m, 4H), 7.03-6.99 (m, 4H), 4.00 (s, 2H), 1.92 (s, 6H).

[0166] 13 C NMR (151 MHz, CDC13) δ 148.9, 145.0, 141.2, 128.1, 128.1, 127.8, 127.8, 126.4, 125.7, 124.6, 65.6, 33.1.

[0167] HRMS (ESI) m / z: [M+H] + Calcd for C 28 H 22 N2 + 391.2169, Found 391.2178.

[0168] Example 20

[0169] A reaction bottle was charged with the 2-vinylaniline compound of the above structural formula (I-1) (0.4 mmol), the photocatalyst 9-thioxanthone of the above structural formula (III) (0.04 mmol), and 4 mL of acetonitrile was injected. The reaction was carried out under light irradiation (λ = 380-410 nm) at room temperature under an air atmosphere for 16 hours. After the reaction was completed, the product was directly subjected to silica gel column chromatography with ethyl acetate / petroleum ether = 1:10 as the eluent to obtain the corresponding azomethine analogue. The product was a white solid with a yield of 48%. The product was characterized as follows:

[0170] Structural formula:

[0171]

[0172] 1 H NMR (600 MHz, CDC13) δ 7.28 (d, J = 7.8 Hz, 2H), 7.22-7.16 (m, 6H), 7.12 (dd, J = 7.6, 1.4 Hz, 2H), 7.10-7.06 (m, 4H), 7.03-6.99 (m, 4H), 4.00 (s, 2H), 1.92 (s, 6H).

[0173] 13 C NMR (151 MHz, CDC13) δ 148.9, 145.0, 141.2, 128.1, 128.1, 127.8, 127.8, 126.4, 125.7, 124.6, 65.6, 33.1.

[0174] HRMS (ESI) m / z: [M+H] + Calcd for C 28 H 22 N2 + 391.2169, Found 391.2178.

[0175] Those skilled in the art can understand that the above description is only a preferred example of the application and is not intended to limit the application. Although the application has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent replacements for part of the technical features. Any modifications, equivalent replacements, etc. made within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A method for preparing a chogerin analogue, characterized in that, Using 2-vinylaniline compounds as raw materials, the raw materials are reacted in an organic solvent under light irradiation conditions of 350nm~380nm, or under blue-violet light irradiation of 380nm~410nm using 9-thioxanthone as a photocatalyst, and the choger base analogues are purified. The structure of the 2-vinylaniline compound is shown in formula (I): ； The structure of the choger base analogue is shown in formula (II) below: ； In the formula: R in the 2-vinylaniline compounds and the Choger base analogues 1 ~R 5 Same, R 1 ~R 5 It is selected from any one of H, C1-C4 alkyl, C1-C4 alkoxy, trifluoromethyl, hydroxymethyl, trifluoromethoxy, halogen, and pinacol boronic acid ester group; The structure of the 9-thioxanone is shown in formula (III): 。 2. The method for preparing the chogerine analogue according to claim 1, characterized in that, The 2-vinylaniline compounds are selected from one of the following compounds: ； ； 。 3. The method for preparing the chogerine analogue according to claim 2, characterized in that, The aforementioned chogerine analogues are selected from one of the following structural formulas: ； ； ； 。 4. The method for preparing the chogerine analogue according to claim 1, characterized in that, The organic solvent is acetonitrile.

5. The method for preparing the chogerine analogue according to claim 1, characterized in that, The molar ratio of the photocatalyst to the 2-vinylaniline compound is 1:(2~100).

6. The method for preparing the chogerine analogue according to claim 5, characterized in that, The molar ratio of the photocatalyst to the 2-vinylaniline compound is 1:

10.

7. The method for preparing the chogerine analogue according to claim 1, characterized in that, The reaction time was 16 hours, the reaction temperature was room temperature, and the reaction was carried out in an inert gas atmosphere.

8. The method for preparing the chogerine analogue according to claim 1, characterized in that, After the reaction was completed, the final product was separated and the catalyst was recovered by column chromatography. The eluent for column chromatography was a mixed solvent of ethyl acetate and petroleum ether, with a volume ratio of ethyl acetate to petroleum ether of 1:10 to 20.

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