Method for electrocatalytic synthesis of quinazolinone derivatives

Abstract

The present invention belongs to the technical field of quinazolinone derivative synthesis. The present invention discloses a method for electrocatalytically synthesizing quinazolin-4(3H)-one derivatives, comprising: adding an o-aminobenzamide derivative, an isothiocyanate derivative, an electrolyte, an additive, methanol, and acetonitrile to an electrolytic cell; and passing a direct current constant current between the anode and cathode electrodes for reaction. The present invention has mild reaction conditions, eliminating the stringent temperature requirements of the reaction. It also eliminates the need for expensive metal catalysts such as lanthanum, making it economical, affordable, and environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of synthesis of quinazolinone derivatives. Background Art

[0002] Quinazolin-4(3H)-one derivatives are unique compounds whose core skeletons fuse a quinazoline ring with a ketocarbonyl group at the 4th position, forming a polycyclic molecular structure. Due to their unique physicochemical properties and broad biological activity, these compounds have shown significant potential in a variety of fields. Modification of their structures by introducing various substituents can further modulate their electronic properties and biological activity. Quinazolin-4(3H)-one derivatives have shown significant potential in drug development, materials science, and other applications. Quinazolin-4(3H)-one derivatives exhibit a variety of biological activities, including antitumor, anti-inflammatory, and antibacterial activities, and hold particular promise in the development of anticancer drugs. Fenquizone, a quinazolin-4(3H)-one derivative, can be used to detect specific enzyme activities. Idelalisib, a PI3Kδ inhibitor, is widely used in the treatment of chronic lymphocytic leukemia and small lymphocytic lymphoma, demonstrating significant efficacy but also potentially associated with adverse reactions. These compounds hold significant potential in the pharmaceutical field.

[0003]

[0004] Ming-Wu Ding's group developed a palladium-catalyzed method for the synthesis of quinazolin-4(3H)-one.

[0005]

[0006] Sabuj Kundu's research group developed a method to synthesize quinazoline-4(3H)-one under 35W blue light.

[0007]

[0008] In the process of synthesizing such compounds, conventional synthesis methods require the use of expensive transition metal catalysts, photocatalysts, strong acids, etc., which makes the reaction process dangerous and costly. Summary of the Invention

[0009] This method uses electrocatalysis to use o-aminobenzamide and phenyl isothiocyanate as reaction substrates, and inexpensive and low-toxic reagents such as acetonitrile and methanol as solvents. The oxidant and reducing agent in the conventional reaction are replaced by the passage of electric current, and a mild and green electrocatalytic method is used to synthesize quinazolin-4(3H)-one compounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the hydrogen spectrum of compound 3aa from Example 1.

[0011] Figure 2 This is the carbon spectrum of compound 3aa from Example 1.

[0012] Figure 3 This is the hydrogen spectrum of compound 3ba from Example 2.

[0013] Figure 4 This is the carbon spectrum of compound 3ba from Example 2.

[0014] Figure 5 This is the hydrogen spectrum of compound 3ca from Example 3.

[0015] Figure 6 This is the carbon spectrum of compound 3ca of Example 3.

[0016] Figure 7 This is the hydrogen spectrum of compound 3da of Example 4.

[0017] Figure 8 This is the carbon spectrum of compound 3da of Example 4.

[0018] Figure 9 This is the hydrogen spectrum of Example 5 compound 3ea.

[0019] Figure 10 This is the carbon spectrum of compound 3ea of ​​Example 5.

[0020] Figure 11 This is the hydrogen spectrum of compound 3fa of Example 6.

[0021] Figure 12 This is the carbon spectrum of compound 3fa in Example 6.

[0022] Figure 13 This is the hydrogen spectrum of Example 7 compound 3ab.

[0023] Figure 14 This is the carbon spectrum of compound 3ab of Example 7.

[0024] Figure 15 This is the hydrogen spectrum of compound 3ac from Example 8.

[0025] Figure 16 This is the carbon spectrum of compound 3ac of Example 8.

[0026] Figure 17 This is the hydrogen spectrum of compound 3ad of Example 9.

[0027] Figure 18 This is the carbon spectrum of compound 3ad of Example 9.

[0028] Figure 19 This is the hydrogen spectrum of compound 3ga of Example 10.

[0029] Figure 20 This is the carbon spectrum of compound 3ga of Example 10.

[0030] Figure 21 This is the hydrogen spectrum of compound 3ha of Example 11.

[0031] Figure 22 This is the carbon spectrum of compound 3ha of Example 11.

[0032] Figure 23 This is the hydrogen spectrum of compound 3ae of Example 12.

[0033] Figure 24 This is the carbon spectrum of compound 3ae of Example 12.

[0034] Figure 25 This is the hydrogen spectrum of Example 13 compound 3af.

[0035] Figure 26 This is the carbon spectrum of compound 3af of Example 13. DETAILED DESCRIPTION

[0036] Example

[0037] The present invention discloses a method for electrocatalytically synthesizing quinazolin-4(3H)-one derivatives. The reaction is carried out under electrical conditions, has good substrate practicality, and a high yield, and various substituted quinazolin-4(3H)-ones are obtained in good yield.

[0038] The raw materials include o-aminobenzamide derivatives and isothiocyanate derivatives, the electrolyte is tetrabutylammonium iodide, the additive is o-phenanthroline, and the solvents are methanol and acetonitrile.

[0039] The experimental equipment includes carbon electrodes (Φ=6 mm, purchased), nickel foam electrodes (1.0 cm×1.0 cm×0.3 cm, purchased), a 20 ml electrolytic cell, a magnet, and a DC regulated power supply.

[0040] A compound having the general formula 1, a compound having the general formula 2, an electrolyte, an additive, methanol, acetonitrile, and a magnet were sequentially added to the electrolytic cell. A constant direct current of 7 mA was passed between the anode and cathode electrodes. The reaction was carried out at 25° C. for 10 h. The reaction progress was monitored by thin-layer chromatography until the reaction was complete. Finally, the compound was separated and purified by silica gel column chromatography (petroleum ether:ethyl acetate) to obtain a compound having the general formula 3. The reaction equation is as follows:

[0041]

[0042] The preparation method of this example comprises the following steps: 1a (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell, a carbon rod is used as an anode, and a nickel foam sheet is used as a cathode, respectively. A DC constant current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25° C. for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3aa is separated and purified by silica gel column chromatography to obtain compound 3aa in a yield of 82%.

[0043] The reaction equation is as follows:

[0044]

[0045] The spectral data of compound 3aa are as follows:

[0046] 1 H NMR (400MHz, CDCl3, ppm): δ8.17 (dd, J=8.0, 1.6Hz, 1H), 7.68-7.57 (m, 4H), 7.52 (t, J= 8.4Hz, 3H), 7.42-7.40 (m, 2H), 7.33-7.23 (m, 3H), 7.08 (t, J=7.4Hz, 1H), 5.96 (s, 1H).

[0047] 13 C NMR (100MHz, CDCl3, ppm): δ162.6, 148.6, 146.4, 137.9, 134.8, 134.6, 130.9, 130.4, 129.1, 129.0, 127.3, 125.7, 124.1, 123.8, 120.9, 118.5.

[0048] Example 2:

[0049] The preparation method of this example comprises the following steps: 1b (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ba is separated and purified by silica gel column chromatography to obtain compound 3ba in a yield of 79%. The reaction equation is as follows:

[0050]

[0051] The spectral data of compound 3ba are as follows:

[0052] 1 H NMR (400MHz, CDCl3, ppm): δ7.98 (s, 1H), 7.67-7.58 (m, 3H), 7.52-7.40 (m, 6H), 7.31 (t, J=7.6Hz, 2H), 7.09 (t, J=7.6Hz, 1H), 5.96 (s, 1H), 2.44 (s, 3H).

[0053] 13 C NMR (100MHz, CDCl3, ppm): δ162.6, 146.4, 145.9, 138.1, 136.3, 134.8, 133.6, 130.9, 130.3, 129.2, 129.0, 126.7, 125.5, 124.0, 120.8, 118.2, 21.1.

[0054] Example 3:

[0055] The preparation method of this example comprises the following steps: 1c (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ca is separated and purified by silica gel column chromatography to obtain compound 3ca in a 74% yield. The reaction equation is as follows:

[0056]

[0057] The spectral data of compound 3ca are as follows:

[0058] 1 H NMR (400MHz, CDCl3, ppm): δ7.81 (dd, J=8.4, 3.2Hz, 1H), 7.68-7.59 (m, 3H), 7.53-7.47 (m, 3H), 7.42-7.36 (m, 3H), 7.31 (t, J=8.0Hz, 2H), 7.16 (t, J=7.6Hz, 1H), 5.96 (s, 1H).

[0059] 13C NMR (100MHz, CDCl3, ppm): δ161.9 (d, J=3.3Hz, 1C), 160.3, 157.9, 146.1, 145.2, 137.8, 134.5, 131.0, 130.5, 129.1 (d, J=3 .3Hz, 1C), 127.8 (d, J=7.7Hz, 1C), 124.3, 123.4 (d, J=23.9Hz, 1C), 121.0, 119.2 (d, J=8.5Hz, 1C), 112.0 (d, J=23.4Hz, 1C).

[0060] Example 4:

[0061] The preparation method of this example comprises the following steps: 1d (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant direct current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, the compound 3da is separated and purified by silica gel column chromatography to obtain a 45% yield. The reaction equation is as follows:

[0062]

[0063] The spectral data of compound 3da are as follows:

[0064] 1 H NMR (400MHz, DMSO, ppm): δ9.39 (s, 1H), 8.74 (s, 1H), 8.09 (d, J=8.4Hz, 1H), 7.75 (dd, J=7.6, 1.6Hz, 1H), 7. 66-7.62 (m, 1H), 7.49 (dd, J=8.4, 1.2Hz, 2H), 7.33-7.29 (m, 2H), 7.20-7.16 (m, 1H), 7.01 (t, J=7.4Hz, 1H).

[0065] 13 C NMR (100MHz, DMSO, ppm): δ 152.0, 142.0, 139.2, 134.0, 133.1, 128.9, 123.0, 122.4, 121.3, 118.4, 117.0, 102.0.

[0066] Example 5:

[0067] The preparation method of this example comprises the following steps: 1e (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ea is separated and purified by silica gel column chromatography to obtain compound 3ea in a 61% yield. The reaction equation is as follows:

[0068]

[0069] The spectral data of compound 3ea are as follows:

[0070] 1 H NMR (400MHz, CDCl3, ppm): δ8.17 (dd, J=8.0, 1.6Hz, 1H), 7.68-7.63 (m, 1H), 7.54-7.52 (m , 3H), 7.34-7.30(m, 4H), 7.27-7.23(m, 1H), 7.15-7.07(m, 3H), 6.10(s, 1H), 3.90(s, 3H).

[0071] 13 C NMR (100MHz, CDCl3, ppm): δ162.9, 160.8, 148.6, 146.8, 138.0, 134.8, 130.3, 129.0, 127.3, 126.7, 125.7, 124.0, 123.7, 120.8, 118.6, 116.2, 55.8.

[0072] Example 6:

[0073] The preparation method of this example comprises the following steps: 1f (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant direct current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 hours. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, the compound 3fa is separated and purified by silica gel column chromatography to obtain a 64% yield. The reaction equation is as follows:

[0074]

[0075] The spectral data of compound 3fa are as follows:

[0076] 1 H NMR (400MHz, CDCl3, ppm): δ8.16 (dd, J=8.0, 1.6Hz, 1H), 7.68-7.64 (m, 1H), 7.53 (d, J=8.8Hz, 3H), 7.42-7.39(m, 2H), 7.36-7.30(m, 4H), 7.28-7.24(m, 1H), 7.12-7.08(m, 1H), 5.90(s, 1H).

[0077] 13 C NMR (100MHz, CDCl3, ppm): δ164.7, 162.7, 162.2, 148.5, 146.3, 137.8, 135.0, 131.2 (d, J=8.9Hz, 1C), 130 .4(d, J=3.4Hz, 1C), 129.1, 127.3, 125.8, 124.1 (d, J=36.1Hz, 1C), 121.0, 118.4, 118.1 (d, J=23.0Hz, 1C).

[0078] Example 7:

[0079] The preparation method of this example comprises the following steps: 1a (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2b (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ab is separated and purified by silica gel column chromatography to obtain compound 3ab in a 67% yield. The reaction equation is as follows:

[0080]

[0081] The spectral data of compound 3ab are as follows:

[0082] 1 H NMR (400MHz, CDCl3, ppm): δ8.18 (dd, J=8.0, 1.6Hz, 1H), 7.71-7.61 (m, 6H), 7.57-7.54 (m, 3H), 7.42-7.40 (m, 2H), 7.30 (t, J=7.4Hz, 1H), 6.13 (s, 1H).

[0083] 13C NMR (100MHz, CDCl3, ppm): δ162.4, 148.1, 145.7, 141.1, 135.0, 134.3, 131.1, 130.6, 129.1, 127.4, 12 6.2 (q, J=3.7Hz, 1C), 125.7 (q, J=32.7Hz, 1C), 125.6 (q, J=270.0Hz, 1C), 124.4, 122.9, 120.1, 118.8.

[0084] Example 8:

[0085] The preparation method of this example comprises the following steps: 1a (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2c (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ac is separated and purified by silica gel column chromatography to obtain compound 3ac in a 79% yield. The reaction equation is as follows:

[0086]

[0087] The spectral data of compound 3ac are as follows:

[0088] 1 H NMR (400MHz, CDCl3, ppm): δ8.17 (dd, J=8.0, 1.6Hz, 1H), 7.67-7.58 (m, 4H), 7.51 (d, J=8.4H z, 1H), 7.42-7.39 (m, 4H), 7.34-7.32 (m, 2H), 7.26-7.22 (m, 1H), 5.89 (s, 1H), 1.30 (s, 9H).

[0089] 13 C NMR (100MHz, CDCl3, ppm): δ162.6, 148.7, 147.2, 146.6, 135.2, 134.8, 134.7 , 130.9, 130.3, 129.1, 127.3, 125.8, 125.7, 123.6, 120.8, 118.5, 34.4, 31.5.

[0090] Example 9:

[0091] The preparation method of this example comprises the following steps: 1a (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2d (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ad is separated and purified by silica gel column chromatography to obtain compound 3ad in a 53% yield. The reaction equation is as follows:

[0092]

[0093] The spectral data of compound 3ad are as follows:

[0094] 1 H NMR (400MHz, CDCl3, ppm): δ8.14 (dd, J=8.0, 1.6Hz, 1H), 7.64-7.60 (m, 1H), 7.58-7.54 (m, 2H), 7.51-7.43 (m, 2 H), 7.32-7.28 (m, 4H), 7.25-7.23 (m, 3H), 7.18 (t, J=7.4Hz, 1H), 4.66 (d, J=5.6Hz, 2H), 4.40 (t, J=5.4Hz, 1H).

[0095] 13 C NMR (100MHz, CDCl3, ppm): δ162.8, 149.5, 149.5, 138.5, 134.8, 130.7, 130.0, 128.9, 128.8, 127.6, 127.5, 127.4, 125.2, 122.9, 117.9, 45.6.

[0096] Example 10:

[0097] The preparation method of this example comprises the following steps: 1 g (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant direct current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, the compound 3ga is separated and purified by silica gel column chromatography to obtain compound 3ga in a 70% yield. The reaction equation is as follows:

[0098]

[0099] The spectral data of compound 3ga are as follows:

[0100] 1 H NMR (400MHz, CDCl3, ppm): δ8.11 (d, J=2.4Hz, 1 H), 7.67-7.64 (m, 2H), 7.62-7.56 (m, 2H), 7.48-7.45 (m, 3H), 7.41-7.39 (m, 2H), 7.31 (t, J=7.8Hz, 2H), 7.10 (t, J=7.4Hz, 1H), 6.01 (s, 1H).

[0101] 13 C NMR (100MHz, CDCl3, ppm): δ161.6, 147.1, 146.7, 137.6, 135.2, 134.3, 131.1, 130.6, 129.2, 129.1, 127.3, 126.5, 124.5, 121.2, 119.5.

[0102] Example 11:

[0103] The preparation method of this example comprises the following steps: 1h (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2a (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 hours. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, the compound 3ha is separated and purified by silica gel column chromatography to obtain a 76% yield. The reaction equation is as follows:

[0104]

[0105] The spectral data of compound 3ha are as follows:

[0106] 1 H NMR (400MHz, DMSO, ppm): δ8.82 (d, J=6.4Hz, 2H), 7.98 (d, J=7.6Hz, 1H), 7.80 (s, 1H), 7.67 (t, J=7.4Hz, 1H), 7. 61 (d, J=6.0Hz, 2H), 7.50 (d, J=6.0Hz, 2H), 7.31 (t, J=8.2Hz, 3H), 7.25 (t, J=7.4Hz, 1H), 7.09 (t, J=7.4Hz, 1H).

[0107] 13C NMR (100MHz, DMSO, ppm): δ 161.4, 151.5, 148.7, 147.4, 142.9, 138.8, 134.8, 128.1, 126.5, 125.1, 124.9, 123.9, 123.7, 123.1, 117.7.

[0108] Example 12:

[0109] The preparation method of this example comprises the following steps: 1a (0.2 mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2e (0.4 mmol) are sequentially added to an electrolytic cell. A carbon rod is used as the anode, and a nickel foam sheet is used as the cathode. A constant DC current of 7 mA is passed between the anode and cathode electrodes. The reaction is carried out at 25°C for 10 h. The reaction progress is monitored by thin-layer chromatography until the reaction is complete. Finally, compound 3ae is separated and purified by silica gel column chromatography to obtain compound 3ae in an 81% yield. The reaction equation is as follows:

[0110]

[0111] The spectral data of compound 3ae are as follows:

[0112] 1 H NMR (400MHz, CDCl3, ppm): δ8.16 (d, J=7.6Hz, 1H), 7.66-7.56 (m, 4H), 7.50 (d, J=8.4Hz, 1H ), 7.41-7.36 (m, 4H), 7.25-7.21 (m, 1H), 7.11 (d, J=8.0Hz, 1H), 5.87 (s, 1H), 2.31 (s, 3H).

[0113] 13 C NMR (100MHz, CDCl3, ppm): 6162.7, 148.8, 146.7, 135.3, 134.8, 134.7, 133.9, 130.9, 130.3, 129.5, 129.1, 127.3, 125.7, 123.6, 121.3, 118.4, 21.0.

[0114] Example 13:

[0115] The preparation method of this embodiment comprises the following steps: adding 1a (0.2

[0116] mmol), tetrabutylammonium iodide (0.4 mmol), o-phenanthroline (0.4 mmol), methanol (2.5 mL), acetonitrile (2.5 mL), a magnet, and 2f (0.4 mmol) were added. A carbon rod was used as the anode and a nickel foam sheet was used as the cathode. A constant DC current of 7 mA was passed between the anode and cathode electrodes. The reaction was allowed to proceed at 25°C for 10 h. The reaction progress was monitored by thin-layer chromatography until completion. Finally, compound 3af was separated and purified by silica gel column chromatography to obtain compound 3af in a 71% yield. The reaction equation is as follows:

[0117]

[0118] The spectral data of compound 3af are as follows:

[0119] 1 H NMR (400MHz, CDCl3, ppm): δ8.16 (dd, J=8.0, 1.6Hz, 1H), 7.68-7.57 (m, 4H), 7.52-7.45 (m, 3H), 7.41-7.38 (m, 2H), 7.28-7.24 (m, 3H), 5.94 (s, 1H).

[0120] 13 C NMR (100MHz, CDCl3, ppm): δ162.5, 148.3, 146.2, 136.5, 134.9, 134.5, 131.0, 130.5, 129.1, 129.0, 128.9, 127.3, 125.7, 124.0, 122.2, 118.6.

[0121] The present invention has mild reaction conditions, solves the harsh temperature requirement in the reaction, and does not require expensive metal catalyst lanthanum, which is economical, affordable, and environmentally friendly.

Claims

1. A method for electrocatalytic synthesis of quinazolin-4(3H)-one derivatives, characterized in that: include: An o-aminobenzamide derivative, an isothiocyanate derivative, an electrolyte, an additive, methanol, and acetonitrile are added to an electrolytic cell, and a direct current constant current is passed between the anode and cathode electrodes to react; The equation for the reaction is: ; The structural formula of the o-aminobenzamide derivative is: ; Among them, R 1 is hydrogen, methyl, fluorine or chlorine; R 2 is phenyl, hydrogen, 4-methoxyphenyl, 4-fluorophenyl, 4-pyridyl or 4-chlorophenyl; The structural formula of the isothiocyanate derivative is: ; Among them, R 3 is phenyl, 4-trifluoromethylphenyl, 4-tert-butylphenyl, benzyl, 4-tolyl and 4-chlorophenyl; The electrolyte is tetrabutylammonium iodide; The additive is o-phenanthroline; The amount ratio of the anthranilamide derivative, the isothiocyanate derivative, the electrolyte and the additive is 1:2:2:2; The volume ratio of methanol to acetonitrile is 1:1; The anode is a carbon rod, and the cathode is a nickel foam sheet; The DC constant current is 7 mA; The reaction temperature was 25° C., and the reaction time was 10 h.

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