A method for electrochemical synthesis of phenanthridinone and spirocyclic oxindole compounds

Abstract

This invention discloses a method for the electrochemical synthesis of phenanthridinone and spirocyclic oxindole compounds. Using various iodine-substituted benzamides, deiodinated and cyclized under efficient, environmentally friendly electrochemical conditions, 14 phenanthridinone compounds and 10 spirocyclic oxindole compounds were selectively synthesized. This method offers advantages such as high atom economy, the absence of an additional reducing agent, and good functional group tolerance. Furthermore, experiments have shown that the introduction of electron-withdrawing groups on the benzene ring of the iodine-substituted benzamides can effectively increase the yield of the spirocyclic oxindole. These results indicate that the selectivity of the reaction depends primarily on the reaction conditions and substrate structure.

Description

Technical Field

[0001] The invention relates to nitrogen-containing heterocyclic compounds, and specifically discloses a method for synthesizing phenanthridone and spirocyclic oxindole compounds from iodobenzamide under electrochemical conditions, and applications of the compounds. Background Art

[0002] Nitrogen-containing heterocyclic compounds exhibit a wide range of biological activities, especially phenanones and spirooxindoles, which are common structural motifs in many natural alkaloids and pharmaceutically active compounds. Therefore, the development of efficient synthetic methods for phenanones and spirooxindoles has attracted considerable attention from chemists.

[0003] Over the past few decades, chemists have developed numerous methods for constructing phenanones and their derivatives. In particular, palladium-catalyzed intramolecular dehydrogenative cyclization strategies to form phenanones have been significantly developed. Despite significant progress in the synthesis of phenanones, current methods typically require the use of metal catalysts or sensitive phosphine ligands as additives. For the synthesis of spirocyclic oxindoles, a commonly used strategy is the samarium(II)-mediated intramolecular radical cyclization of o-halogenated benzamides.

[0004] From the perspective of sustainable chemistry, the development of a general, efficient, concise, and metal-free method for the synthesis of phenanthridinones and spirocyclic oxindoles remains highly desirable. Summary of the Invention

[0005] Organic electrochemistry is a green and efficient synthesis method with mild reaction conditions, strong controllability, and no need for additional oxidants or reducing agents. Therefore, the present invention discloses a simple and efficient electrochemical reduction cyclization of iodobenzamides to selectively construct phenanthridinone and spirocyclic oxindole without the need for metal catalysts and additional reducing agents.

[0006] The technical solution for achieving the purpose of the present invention is:

[0007] A method for electrochemically synthesizing phenanthridinone and spirocyclic oxindole compounds, the general formula of the synthesis method is as follows

[0008]

[0009] Among them, R 1 , R 2 = methyl, ethyl, isopropyl, tert-butyl, methoxy, halogen, etc.;

[0010] Electrolytes include: tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium iodide, etc.

[0011] Bases include potassium carbonate, cesium carbonate, potassium tert-butoxide, and the like.

[0012] A method for electrochemically synthesizing a phenanthridinone compound comprises the following steps:

[0013] (1) 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L electrolyte, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of base were placed in a 10 mL three-necked round-bottom flask, 6 mL of acetonitrile was added to dissolve the mixture, a zinc sheet was used as the anode, and a platinum sheet was used as the cathode. The mixture was stirred at a constant current of 10-20 mA and 40-60°C for 2-3 hours. The reaction progress was monitored by TLC.

[0014] (2) After the reaction is completed, the mixture is extracted with 10 mL of ethyl acetate, the organic layer is dried over anhydrous MgSO4, the solvent is evaporated under reduced pressure, and the residue is purified by column chromatography to obtain the target product, a phenanthridinone compound.

[0015] Furthermore, in the synthesis method, in the column chromatography purification in step (2), the volume ratio of the eluent is silica gel: n-hexane / ethyl acetate = 10-20:1.

[0016] A method for electrochemically synthesizing a spirocyclic oxindole compound comprises the following steps:

[0017] (A) 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of electrolyte, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask. 6 mL of acetonitrile / water was added for dissolution. A zinc sheet was used as the anode and a platinum sheet as the cathode. The reaction was stirred at a constant current of 10-20 mA at room temperature for 2-3 hours. The reaction progress was monitored by TLC.

[0018] (B) After the reaction was completed, the mixture was extracted with 10 mL of ethyl acetate, the organic layer was dried over anhydrous MgSO 4 , the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography to obtain the target product, the spirocyclic oxindole compound.

[0019] Furthermore, in the synthesis method, the volume ratio of acetonitrile / water in step (A) is 6:2.

[0020] Furthermore, in the synthesis method, in the column chromatography purification in step (B), the volume ratio of the eluent is silica gel: n-hexane / ethyl acetate = 10-20:1.

[0021] Phenanthridinone and spirocyclic oxindole compounds have good pharmacological activities. For example, phenanthridinone has antitumor (J. Med. Chem., 2005, 48, 792-804), antiviral (Nat. Prod. Rep., 2009, 26, 363-381) and DNA topoisomerase inhibitory properties (RSC Adv., 2015, 5, 16562-16574), and spirocyclic oxindole compounds are generally used as anticancer (Eur. J. Med. Chem., 2015, 97, 673) and antiviral drugs (Anticancer Agents Med. Chem., 2016, 16, 1315-1324).

[0022] The present invention also includes the use of phenanthridone and spirocyclic oxindole compounds or pharmaceutically acceptable salts thereof in the preparation of anti-tumor drugs.

[0023] The present invention also includes an anti-tumor drug prepared with phenanthridone and spirocyclic oxindole compound or pharmaceutically acceptable salts thereof as active ingredients.

[0024] The present invention provides a mild and efficient electrochemical cyclization of iodine-substituted benzamides to selectively construct phenanthridinone and spirocyclic oxindole compounds. This synthesis method offers advantages such as high atom economy, the absence of an additional reducing agent, and good functional group tolerance. Furthermore, experiments have shown that the introduction of an electron-withdrawing group on the benzene ring of the iodine-substituted benzamide can effectively increase the yield of the spirocyclic oxindole. These results demonstrate that the selectivity of the reaction is primarily dependent on the reaction conditions and substrate structure. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the preparation, structure and characterization of phenanthridinone and spirocyclic oxindole compounds in the examples, but the present invention is not limited thereto.

[0026] Example 1, Preparation and Characterization of Phenanthridinone Compounds:

[0027] Preparation and characterization of 5-methyl-6(5H)-phenanthridinone (2a):

[0028]

[0029] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at 10 mA constant current and 40°C for 2 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1) to obtain the target product phenanthridinone 2a.

[0030] White solid(63%,39.5mg).mp:103.7℃-105.7℃. 1 H NMR (400MHz, CDCl3) δ8.46(d,J=8.1Hz,1H),8.09(d,J=7.5Hz,2H),7.64(t,J=7.6Hz,1H),7.51-7.40(m,2H),7.26-7.17(m,2H),3.69(s,3H). 13 C NMR(100MHz, CDCl3)δ161.4,137.8,133.3,132.2,129.4,128.7,127.8,125.4,123.0,122.3,121.5,119.0,114.9,29.8.HRMS(m / z)(ESI):calcd forC 14 H 11 NO[M+H] + 210.0913,found210.0911.

[0031] Preparation and characterization of 5,7-dimethyl-6(5H)-phenanthridinone (2b):

[0032]

[0033] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of cesium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 15 mA and 50°C for 2.5 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1) to obtain the target product phenanthridinone 2b.

[0034] White solid(79%,52.9mg).mp:82.9℃-84.9℃. 1 H NMR (400MHz, CDCl3) δ7.40-7.35(m,1H),7.10-7.06(m,1H),6.97-6.91(m,2H),6.50(d,J=9. 8Hz,1H),6.43(dd,J=9.8,1.5Hz,1H),6.36-6.35(m,1H),3.30(s,3H),1.60(d,J=1.4Hz,3H). 13 C NMR(100MHz, CDCl3)δ186.3,172.2,154.0,144.3,143.7,130.2,130.1,129.9,127.0,124.1,123.9,109.2,58.8,27.2,19.4.HRMS(m / z)(ESI):calcd for C 15 H 14 NO + [M+H] + 224.1070,found224.1068.

[0035] Preparation and characterization of 5,8-dimethyl-6(5H)-phenanthridinone (2c):

[0036]

[0037] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium hexafluorophosphate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium tert-butoxide were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet as the cathode. The reaction was stirred at 20 mA constant current and 60°C for 3 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product phenanthridinone 2c.

[0038] White solid(54%,36.1mg).mp:106.2℃-108.2℃. 1 H NMR (400MHz, CDCl3) δ8.52(d,J=7.9Hz,1H),8.45(d,J=9.7Hz,1H),7.60(d,J=8.0Hz,1 H),7.56-7.52(m,1H),7.50-7.44(m,2H),7.33-7.28(m,1H),3.80(s,3H),2.95(s,3H). 13 C NMR(100MHz, CDCl3)δ162.2,138.4,137.0,134.5,133.2,128.8,128.0,127.4,127.4,121.7,121.0,114.9,30.5,29.8,26.2.HRMS(m / z)(ESI):calcd for C 15 H 13 NO[M+H] + 224.1070,found 224.1067.

[0039] Preparation and characterization of 5,9-dimethyl-6(5H)-phenanthridinone (2d):

[0040]

[0041] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium iodide, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium carbonate were placed in a 10 mL three-necked round-bottom flask and dissolved in 6 mL of acetonitrile. A zinc sheet was used as the anode and a platinum sheet as the cathode. The reaction was stirred at 10 mA constant current at 40°C for 2 h. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, elution with n-hexane / ethyl acetate = 10:1) to obtain the target product phenanthridinone 2d.

[0042] White solid(43%,28.8mg).mp:105.3℃-107.3℃. 1 H NMR (400MHz, CDCl3) δ8.39(d,J=8.0Hz,1H),8.20(d,J=8.0Hz,1H),7.98(s,1H),7.49(t ,J=7.8Hz,1H),7.35(t,J=7.7Hz,2H),7.26(t,J=7.6Hz,1H),3.75(s,3H),2.52(s,3H). 13 C NMR (100MHz, CDCl3) δ161.8,142.9,138.2,133.6,129.5,129.5,129.0,123.4,123.2,122.4,121.7,119.3,115.1,30.0,22.3.HRMS(m / z)(ESI):calcd for C 15 H 14 NO + [M+H] + 224.1070,found224.1062.

[0043] Preparation and characterization of 9-ethyl-5-methyl-6(5H)-phenanthridinone (2e):

[0044]

[0045] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of cesium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 15 mA and 50°C for 2.5 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1) to obtain the target product phenanthridinone 2e.

[0046] Yellow solid(51%,36.3mg).mp:67.6℃-69.6℃. 1 H NMR (400MHz, CDCl3) δ8.44(d,J=8.1Hz,1H),8.26(d,J=8.1Hz,1H),8.04(s,1H),7.53-7.49(m,1H),7. 39(dd,J=17.1,8.3Hz,2H),7.31-7.27(m,1H),3.78(s,3H),2.84(q,J=7.6Hz,2H),1.37-1.33(m,3H). 13 C NMR (150MHz, CDCl3) δ161.7,149.1,138.2,133.6,129.5,129.1,128.3,123.6 ,123.2,122.4,120.5,119.4,115.1,29.9,29.5,15.5.HRMS(m / z)(ESI):calcd for C 16 H 16 NO + [M+H] + 238.1226, found 238.1231.

[0047] Preparation and characterization of 9-isopropyl-5-methyl-6(5H)-phenanthridinone (2f):

[0048]

[0049] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at 20 mA constant current and 60°C for 3 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product phenanthridinone 2f.

[0050] Yellow oil (53%, 39.9 mg). 1 H NMR (400MHz, CDCl3) δ8.46 (d, J=8.3Hz,

[0051] 1H),8.30(dd,J=8.1,1.5Hz,1H),8.09(d,J=1.9Hz,1H),7.54-7.50(m,1H),7.46(dd,J=8.3,1.7Hz,1H) ,7.39(dd,J=8.5,1.2Hz,1H),7.33-7.28(m,1H),3.79(s,3H),3.15-3.08(m,1H),1.37(d,J=6.9Hz,6H). 13 C NMR (100MHz, CDCl3) δ161.8,153.7,138.2,133.6,129.5,129.1,126.9,123.8 ,123.2,122.4,119.5,119.2,115.1,34.8,30.0,24.0.HRMS(m / z)(ESI):calcd for C 17 H 17 NO[M+H] + 238.1226, found 238.1231.

[0052] Preparation and characterization of 9-methoxy-5-methyl-6(5H)-phenanthridinone (2g):

[0053]

[0054] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium hexafluorophosphate, 0.15 mmol of 1,4-dicyanobenzene and 0.6 mmol of cesium carbonate were placed in a 10 mL three-necked round-bottom flask, 6 mL of acetonitrile was added to dissolve, a zinc sheet was used as an anode and a platinum sheet was used as a cathode, and the reaction was stirred at a constant current of 10 mA and 40 ° C for 2 hours. The reaction progress was monitored by TLC; after the reaction was completed, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was dried under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1 elution) to obtain 2 g of the target product phenanthridinone.

[0055] White solid(54%,38.7mg).mp:151.5℃-153.5℃. 1 H NMR (400MHz, CDCl3) δ8.40(d,J=8.8Hz,1H),8.07(d,J=8.0Hz,1H),7.50-7.44(m,2H),7.29(d ,J=8.4Hz,1H),7.22(t,J=7.6Hz,1H),7.07(dd,J=8.9,2.4Hz,1H),3.93(s,3H),3.70(s,3H). 13 C NMR (100MHz, CDCl3) δ162.9,161.4,138.4,135.4,131.0,129.7,123.2,122.2,119.3,119.0,115.8,115.1,104.4,55.5,29.7.HRMS(m / z)(ESI):calcd for C 15 H 14 NO2 + [M+H] + 240.1019,found240.1027.

[0056] Preparation and characterization of 9-(tert-butyl)-5-methyl-6(5H)-phenanthridinone (2h):

[0057]

[0058] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium iodide, 0.15 mmol of 1,4-dicyanobenzene and 0.6 mmol of potassium tert-butoxide were placed in a 10 mL three-necked round-bottom flask, 6 mL of acetonitrile was added for dissolution, a zinc sheet was used as an anode and a platinum sheet was used as a cathode, and the reaction was stirred at a constant current of 15 mA and 50° C. for 2.5 hours. The reaction progress was monitored by TLC. After the reaction was completed, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1 elution) to obtain the target product phenanthridinone 2h.

[0059] Yellow solid(50%,39.8mg).mp:101.8℃-103.3℃. 1 H NMR (400MHz, CDCl3) δ8.47(d,J=8.4Hz,1H),8.32(d,J=8.0Hz,1H),8.26(s,1H),7.65(dd,J=8.5,1.8Hz,1H),7.55-7.51(t,J=8.0Hz 1H),7.40(d,J=8.4Hz,1H),7.32(t,J=7.5Hz,1H),3.80(s,3H),1.45(s,9H). 13 C NMR (100MHz, CDCl3) δ161.7,155.9,138.3,133.3,129.5,128.8,126.1,123.4 ,123.2,122.4,119.8,117.8,115.2,35.6,31.4,30.0.HRMS(m / z)(ESI):calcd for C 18 H 19 NO[M+H] + 266.1539,found 266.1532.

[0060] Preparation and characterization of 5-methyl-6-oxo-5,6-dihydrophenanthridine-9-acetate (2i):

[0061]

[0062] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at 20 mA constant current and 60°C for 3 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product phenanthridinone 2i.

[0063] White solid(65%,52.1mg).mp:148.9℃-150.2℃. 1 H NMR (400MHz, CDCl3) δ8.43(d,J=8.9Hz,1H),8.14(d,J=8.1Hz,1H),7.56(d,J=2.4Hz,1H),7.52-7.48(m, 1H),7.34(d,J=8.4Hz,1H),7.27(t,J=8.0Hz,1H),7.10(dd,J=8.8,2.4Hz,1H),3.95(s,3H),3.74(s,3H). 13 C NMR (100MHz, CDCl3) δ163.0,161.6,138.6,135.6,131.2,129.8,129.2,123.3, 122.3,119.4,119.2,116.0,115.2,104.5,55.7,29.9.HRMS(m / z)(ESI):calcd forC 16 H 13 NaNO3 + [M+Na] + 290.0788,found 290.0783.

[0064] Preparation and characterization of 9-fluoro-5-methyl-6(5H)-phenanthridinone (2j):

[0065]

[0066] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of cesium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 10 mA and 40°C for 2 hours, and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1) to obtain the target product phenanthridinone 2j.

[0067] White solid(61%,41.6mg).mp:144.4℃-146.2℃. 1 H NMR (400MHz, CDCl3) δ8.50(dd,J=8.8,6.0Hz,1H),8.05(d,J=8.0Hz,1H),7.77(dd,J=10.3,2.4Hz,1H) ,7.53(t,J=7.8Hz,1H),7.35(d,J=8.4Hz,1H),7.29(t,J=8.0Hz,1H),7.25-7.20(m,1H),3.74(s,3H). 13 C NMR (100MHz, CDCl3) δ165.6(d,J=250.0Hz),161.0,138.5,136.2(d,J=10.0Hz),132.2(d,J=10.0Hz),130.4,1 23.6, 122.7, 122.2 (d, J = 3.0Hz), 118.6 (d, J = 3.0Hz), 116.3 (d, J = 22.0Hz), 115.3, 107.6 (d, J = 23.0Hz), 30.0. 19 F NMR(376MHz,CDCl3)δ-105.96.HRMS(m / z)(ESI):calcd for C 14 H 10 FNO[M+H] + 228.0819,found 228.0833.

[0068] Preparation and characterization of 5-methylbenzo[j]phenanthridin-6(5H)-one (2k):

[0069]

[0070] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium hexafluorophosphate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium tert-butoxide were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 15 mA and 50°C for 2.5 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1) to obtain the target product phenanthridinone 2k.

[0071] White solid(39%,30.3mg).mp:122.4℃-124.6℃. 1 H NMR (400MHz, CDCl3) δ8.89-8.87(m,1H),8.65(d,J=9.8Hz,1H),8.50(d,J=8.6Hz,1H),8.02-8.00(m,1H),7.95(d, J=8.6Hz,1H),7.68-7.65(m,2H),7.62-7.58(m,1H),7.53(dd,J=8.4,1.3Hz,1H),7.39-7.35(m,1H),3.86(s,3H). 13 C NMR (100MHz, CDCl3) δ162.0,138.6,136.3,132.9,129.3,129.0,128.7,128.7,128 .0,127.9,126.8,124.7,124.0,122.1,119.7,115.0,30.6.HRMS(m / z)(ESI):calcd for C 18 H 13 NO[M+H] + 260.1070,found 260.1063.

[0072] Preparation and characterization of 3,5-dimethylphenanthridin-6(5H)-one (2l):

[0073]

[0074] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium iodide, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium carbonate were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at 20 mA constant current and 60°C for 3 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product phenanthridinone 2l.

[0075] White solid(54%,36.1mg).mp:108.2℃-110.3℃. 1 H NMR (400MHz, CDCl3) δ8.50(dd,J=8.0,1.5Hz,1H),8.16(d,J=8.1Hz,1H),8.08(d,J=8.2Hz,1H),7. 71-7.67(m,1H),7.54-7.50(m,1H),7.14(s,1H),7.09(d,J=8.1Hz,1H),3.75(s,3H),2.47(s,3H). 13 C NMR (100MHz, CDCl3) δ161.9,140.0,138.1,133.8,132.4,129.0,127.5,125.3,123.7,123.2,121.5,116.9,115.5,30.0,22.0.HRMS(m / z)(ESI):calcd for C 15 H 13 NO[M+H] + 224.1070,found 224.1073.

[0076] Preparation and characterization of 2,5-dimethylphenanthridin-6(5H)-one (2m):

[0077]

[0078] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of cesium carbonate were placed in a 10 mL three-necked round-bottom flask, 6 mL of acetonitrile was added for dissolution, a zinc sheet was used as an anode, a platinum sheet was used as a cathode, and the reaction was stirred at a constant current of 10 mA at 40° C. for 2 hours. The reaction progress was monitored by TLC. After the reaction was completed, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO 4 , the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1 elution) to obtain the target product phenanthridinone 2m.

[0079] White solid(42%,28.1mg).mp:134.0℃-136.2℃. 1 H NMR(400MHz, CDCl3)δ8.52(dd,J=8.0,1.5Hz,1H),8.22(d,J=8.1Hz,1H),8.02(s,1H),7.74-7.69(m,1H), 7.57-7.53(t,J=8.0Hz,1H),7.32(dd,J=8.5,1.9Hz,1H),7.26(t,J=8.5Hz,1H),3.76(s,3H),2.46(s,3H). 13 C NMR (100MHz, CDCl3) δ161.6,136.0,133.5,132.3,131.9,130.6,129.0,127.9,125.7,123.4,121.6,119.1,115.0,30.0,21.1.HRMS(m / z)(ESI):calcd for C 15 H 14 NO + [M+H] + 224.1070,found224.1066.

[0080] Preparation and characterization of 5-isopentyl-[1,3]dioxo[4,5-j]phenanthridin-6(5H)-one (2n):

[0081]

[0082] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of potassium tert-butoxide were placed in a 10 mL three-necked round-bottom flask, 6 mL of acetonitrile was added for dissolution, a zinc sheet was used as an anode, a platinum sheet was used as a cathode, and the reaction was stirred at a constant current of 15 mA and 50° C. for 2.5 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO 4 , the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1 elution) to obtain the target product phenanthridinone 2n.

[0083] White solid(40%,37.1mg).mp:111.2℃-113.6℃. 1 H NMR (400MHz, CDCl3) δ8.06(d,J=9.6Hz,1H),7.86(s,1H),7.58(s,1H),7.48-7.45(m,1H),7.34(d,J=8 .5Hz,1H),7.23(d,J=9.3Hz,1H),6.08(s,2H),4.37-4.33(m,2H),1.21(s,3H),1.02(d,J=6.6Hz,6H). 13 C NMR (100MHz, CDCl3) δ160.9,152.3,148.5,136.7,130.6,129.0,123.3,122.2,121.4, 119.6,115.1,107.0,102.1,100.5,41.6,36.2,26.8,22.7.HRMS(m / z)(ESI):calcdfor C 19 H 19 NO3[M+H] + 310.1438,found 310.1438.

[0084] Example 2, Preparation and Characterization of Spirocyclic Oxindole Compounds:

[0085] Preparation and characterization of 1'-methylspiro[cyclohexane-1,3'-indoline]-2,5-diene-2'-one (3a):

[0086]

[0087] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 10 mA at room temperature for 2 hours, and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1) to obtain the target product spirocyclic oxindole compound 3a.

[0088] White solid(60%,37.9mg).mp:70.4℃-72.6℃. 1 H NMR (400MHz, CDCl3) δ7.24(t,J=6.4Hz,1H),7.08(d,J=7.5Hz,1H),7.02(t,J=7.4Hz,1H),6 .80(d,J=7.7Hz,1H),6.11-6.07(m,2H),5.36-5.32(m,2H),3.19(s,3H),2.96-2.78(m,2H). 13 C NMR(100MHz, CDCl3)δ178.0,143.0,134.2,128.5,127.3,124.8,123.9,123.0,108.1,51.8,26.7,25.8.HRMS(m / z)(ESI):calcd for C 14 H 13 NO[M+Na] + 234.0889,found 234.0877.

[0089] Preparation and characterization of 1',6'-dimethylspiro[cyclohexane-1,3'-indoline]-2,5-dien-2'-one (3b):

[0090]

[0091] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 15 mA at room temperature for 2.5 hours, and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1) to obtain the target product spirocyclic oxindole compound 3b.

[0092] White solid(58%,39.1mg).mp:120.9℃-122.3℃. 1 H NMR(400MHz, CDCl3) δ6.99(d,J=7.5Hz,1H),6.87(d,J=7.5Hz,1H),6.67(s,1H),6.1 3-6.09(m,2H),5.37(d,J=10.2Hz,2H),3.21(s,3H),2.99-2.81(m,2H),2.39(s,3H). 13 CNMR(100MHz, CDCl3)δ178.2,143.1,138.7,131.4,127.1,124.5,124.1,123.5,109.0,51.6,26.6,25.8,21.9.HRMS(m / z)(ESI):calcd for C 15 H 15 NO,[M+Na] + 248.1046,found 248.1043.

[0093] Preparation and characterization of 6'-fluoro-1'-methylspiro[cyclohexane-1,3'-indoline]-2,5-dien-2'-one (3c):

[0094]

[0095] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 20 mA at room temperature for 3 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product spirocyclic oxindole compound 3c.

[0096] White solid(56%,38.5mg).mp:120.3℃-122.6℃. 1 H NMR (400MHz, CDCl3) δ7.26-7.23(m,1H),6.95-6.90(m,1H),6.79(dd,J=8.8,2. 3Hz,1H),6.35-6.31(m,2H),5.57-5.53(m,2H),3.41(s,3H),3.20-3.01(m,2H). 13 C NMR (100MHz, CDCl3) δ178.2, 163.3 (d, J = 243.0Hz), 144.4 (d, J = 12.0Hz), 129.5 (d, J = 3.0Hz), 127.5, 125.8 (d, J = 9.0Hz), 123.7, 108.9 (d, J = 23.0Hz), 96.9 (d, J = 28.0Hz), 51.3, 26.8, 25.7. 19 F NMR(376MHz,CDCl3)δ-111.93.HRMS(m / z)(ESI):calcd for C 14 H 12 FNO,[M+Na] + 252.0795,found 252.0796.

[0097] Preparation and characterization of 1'-methyl-6'-(trifluoromethyl)spiro[cyclohexane-1,3'-indolin]-2,5-dien-2'-one (3d):

[0098]

[0099] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium iodide, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 10 mA at room temperature for 2 hours. The reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, eluted with n-hexane / ethyl acetate = 10:1) to obtain the target product spirocyclic oxindole compound 3d.

[0100] White solid(73%,61.1mg).mp:110.2℃-112.3℃. 1 H NMR (400MHz, CDCl3) δ7.32(d,J=7.7Hz,1H),7.20(d,J=7.7Hz,1H),7.04(s, 1H),6.18-6.14(m,2H),5.36-5.32(m,2H),3.25(s,3H),3.00-2.82(m,2H). 13 C NMR (100MHz, CDCl3) δ177.6, 143.7, 137.9, 131.0 (d, J = 32.0Hz), 128.1, 125.1, 124.0 (d,J=271.0Hz),122.9,120.1(d,J=4.0Hz),104.9(d,J=3.0Hz),51.73,26.82,25.76. 19 F NMR(376MHz,CDCl3)δ-62.36.HRMS(m / z)(ESI):calcd for C 15 H 12 F3NONa + ,[M+Na] + 302.0763,found 302.0769.

[0101] Preparation and characterization of 6'-chloro-1'-methylspiro[cyclohexane-1,3'-indoline]-2,5-dien-2'-one (3e):

[0102]

[0103] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 15 mA at room temperature for 2.5 hours, and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1) to obtain the target product spirocyclic oxindole compound 3e.

[0104] White solid(69%,50.7mg).mp:140.8℃-142.5℃. 1 H NMR (400MHz, CDCl3) δ7.01 (d, J = 1.1Hz, 2H), 6.83 (t, J = 1.2Hz, 1H), 6.15-6.11 (m, 2H), 5.35-5.31 (m, 2H), 3.20 (s, 3H), 2.99-2.80 (m, 2H). 13 C NMR(100MHz, CDCl3)δ177.9,144.2,134.2,132.6,127.7,125.8,123.4,122.8,108.8,51.5,26.8,25.8.HRMS(m / z)(ESI):calcd for C 14 H 13 ClNO + ,[M+H] + 246.0680,found 246.0681.

[0105] Preparation and characterization of 5'-chloro-1'-methylspiro[cyclohexane-1,3'-indoline]-2,5-dien-2'-one (3f):

[0106]

[0107] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 20 mA at room temperature for 3 hours, and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product spirocyclic oxindole compound 3f.

[0108] White solid(51%,37.5mg).mp:126.6℃-128.2℃. 1 H NMR (400MHz, CDCl3) δ7.22(d,J=8.2Hz,1H),7.06(s,1H),6.73(d,J=7.9Hz,1 H),6.15-6.11(m,2H),5.33(d,J=8.1Hz,2H),3.15(s,3H),2.96-2.79(m,2H). 13 C NMR(150MHz, CDCl3)δ177.5,141.6,135.8,128.4,127.9,125.4,123.2,109.1,51.9,29.8,26.8,25.8.HRMS(m / z)(ESI):calcd forC 14 H 12 ClNO,[M+H] + 246.0680,found246.0683.

[0109] Preparation and characterization of 1'-methyl-2'-oxospiro[cyclohexane-1,3'-indoline]-2,5-diene-6'-carbonitrile (3 g):

[0110]

[0111] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium hexafluorophosphate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, 6 mL of acetonitrile / water (6:2) was added to dissolve, a zinc sheet was used as an anode, a platinum sheet was used as a cathode, and the reaction was stirred at a constant current of 10 mA at room temperature for 2 hours. The reaction progress was monitored by TLC. After the reaction was completed, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1 elution) to obtain 3 g of the target product spirocyclic oxindole compound.

[0112] White solid(53%,37.5mg).mp:160.0℃-162.3℃. 1 H NMR (400MHz, CDCl3) δ7.37 (dd, J=7.6, 1.4Hz, 1H), 7.19 (d, J=7.6Hz, 1H), 7.06 (s,1H),6.20-6.16(m,2H),5.34-5.31(m,2H),3.24(s,3H),3.01-2.83(m,2H). 13 C NMR(100MHz, CDCl3)δ177.2,143.9,139.2,128.5,127.7,125.5,122.5,118.8,112.2,110.7,51.8,26.9,25.8.HRMS(m / z)(ESI):calcdfor C 15 H 12 N2O,[M+H] + 237.1022,found237.1012.

[0113] Preparation and characterization of methyl 1'-methyl-2'-oxospiro[cyclohexane-1,3'-indoline]-2,5-diene-6-carboxylate (3h):

[0114]

[0115] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium iodide, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as an anode and a platinum sheet was used as a cathode. The reaction was stirred at a constant current of 15 mA at room temperature for 2.5 hours, and the reaction progress was monitored by TLC. After the reaction was completed, the mixture was extracted with ethyl acetate (10 mL), the organic layer was dried over anhydrous MgSO4, the solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 15:1) to obtain the target product spirocyclic indole compound 3h.

[0116] White solid(59%,47.6mg).mp:158.4℃-160.2℃. 1 H NMR (400MHz, CDCl3) δ7.77(dd,J=7.7,1.4Hz,1H),7.48(d,J=1.5Hz,1H),7.17(d,J=7.7Hz ,1H),6.18-6.13(m,2H),5.37-5.33(m,2H),3.92(s,3H),3.26(s,3H),3.01-2.82(m,2H). 13 C NMR(150MHz, CDCl3)δ177.7,166.8,143.4,139.2,130.7,128.0,125.0,124.7,123.1,108.8,52.4,52.0,26.9,25.8.HRMS(m / z)(ESI):calcd for C 16 H 15 NO3,[M+Na] + 292.0944,found 292.0941.

[0117] Preparation and characterization of 1',2-dimethylspiro[cyclohexane-1,3'-indoline]-2,5-dien-2'-one (3i):

[0118]

[0119] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetrabutylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The reaction was stirred at a constant current of 20 mA at room temperature for 3 hours, and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 20:1) to obtain the target product spirocyclic oxindole compound 3i.

[0120] White solid(56%,37.8mg).mp:61.1℃-63.4℃. 1 H NMR (400MHz, CDCl3) δ7.26-7.22(m,1H),7.05-7.01(m,2H),6.81(d,J=7.8Hz,1H),6.05-6.00(m ,1H),5.81-5.80(m,1H),5.29-5.26(m,1H),3.21(s,3H),2.97-2.79(m,2H),1.29-1.28(m,3H). 13 C NMR(150MHz, CDCl3)δ178.0,143.6,133.6,129.7,128.4,126.6,124.4,124.3,123.7,123.1,108.0,55.3,27.0,26.6,18.9.HRMS(m / z)(ESI):calcd for C 15 H 15 NaNO + ,[M+Na] + 248.1046,found248.1039.

[0121] Preparation and characterization of 1'-methyl-2'-oxo-N,N-dipropylspiro[cyclohexane-1,3'-indoline]-2,5-diene-4-sulfonamide (3j):

[0122]

[0123] 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L of tetraethylammonium tetrafluoroborate, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile / water (6:2) was added for dissolution. A zinc sheet was used as an anode and a platinum sheet was used as a cathode. The reaction was stirred at a constant current of 10 mA at room temperature for 2 hours, and the reaction progress was monitored by TLC. After the reaction was completed, the mixture was extracted with ethyl acetate (10 mL), and the organic layer was dried over anhydrous MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by column chromatography (silica gel, n-hexane / ethyl acetate = 10:1) to obtain the target product spirocyclic oxindole compound 3j.

[0124] Yellow solid(50%,56.1mg).mp:111.7℃-113.8℃. 1 H NMR (400MHz, CDCl3) δ7.40 (d, J = 6.3Hz, 1H), 7.26-7.22 (m, 1H), 7.03 (t, J = 7.5Hz, 1H), 6.79 (d, J = 7.7Hz, 1H), 6.11 (dd, J = 10. 0,3.6Hz,2H),5.67(dd,J=10.1,1.8Hz,2H),4.49-4.46(m,1H),3.22-3.17(m,7H),1.64-1.55(m,4H),0.86(t,J=7.3Hz,6H). 13 C NMR(100MHz, CDCl3)δ176.0,143.2,131.2,129.8,129.1,125.9,123.6,121.0,108.2,59.8,52.3,50.0,26.8,22.4,11.2.HRMS(m / z)(ESI):calcd for C 20 H 27 N2O3S,[M+H] + 375.1737,found 375.1735.

[0125] Phenanthridinone and spirocyclic oxindole compounds are important nitrogen-containing heterocyclic compounds, common structural motifs in many natural alkaloids and pharmaceutically active compounds, and exhibit a wide range of biological activities. In this example, 14 phenanthridinone compounds and 10 spirocyclic oxindole compounds were selectively synthesized using various iodine-substituted benzamides through deiodination cyclization under efficient and environmentally friendly electrochemical conditions. These compounds or their pharmaceutically acceptable salts are used as active ingredients in the preparation of anti-tumor drugs.

Claims

1. A method for electrochemically synthesizing phenanthridinone and spirocyclic oxindole compounds, characterized in that: The synthetic route is as follows: Wherein, the electrolyte is: tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate or tetrabutylammonium iodide; Constant current: 10 ~ 20 mA; The base is: potassium carbonate, cesium carbonate or potassium tert-butoxide.

2. The method for electrochemically synthesizing phenanthridinone and spirocyclic oxindole compounds according to claim 1, characterized in that: The synthesis method of the phenanthridinone compound comprises the following steps: (1) 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L electrolyte, 0.15 mmol of 1,4-dicyanobenzene, and 0.6 mmol of base were placed in a 10 mL three-necked round-bottom flask, and 6 mL of acetonitrile was added to dissolve the mixture. A zinc sheet was used as the anode and a platinum sheet was used as the cathode. The mixture was stirred at a constant current of 10-20 mA and 40-60 °C for 2-3 hours. The reaction progress was monitored by TLC. (2) After the reaction is completed, the mixture is extracted with 10 mL of ethyl acetate, the organic layer is dried over anhydrous MgSO4, the solvent is evaporated under reduced pressure, and the residue is purified by column chromatography to obtain the target product, a phenanthridinone compound.

3. The method for electrochemical synthesis of phenanthridinone and spirocyclic oxindole compounds according to claim 2, characterized in that: In the synthesis method, in step (2), the column chromatography purification is performed with an eluent volume ratio of silica gel: n-hexane / ethyl acetate = 10~20:

1.

4. The method for electrochemically synthesizing phenanthridinone and spirocyclic oxindole compounds according to claim 1, characterized in that: The synthesis method of the spirocyclic oxindole compound comprises the following steps: (A) 0.3 mmol of N-(2-iodophenyl)-N-methylbenzamide, 0.15 mol / L electrolyte, and 0.15 mmol of 1,4-dicyanobenzene were placed in a 10 mL three-necked round-bottom flask. 6 mL of acetonitrile / water was added for dissolution. A zinc sheet was used as the anode and a platinum sheet as the cathode. The reaction was stirred at a constant current of 10-20 mA at room temperature for 2-3 hours. The reaction progress was monitored by TLC. (B) After the reaction is completed, the mixture is extracted with 10 mL of ethyl acetate, the organic layer is dried over anhydrous MgSO4, the solvent is evaporated under reduced pressure, and the residue is purified by column chromatography to obtain the target product, the spirocyclic oxindole compound.

5. The method for electrochemically synthesizing phenanthridinone and spirocyclic oxindole compounds according to claim 4, characterized in that: In the synthesis method, the volume ratio of acetonitrile / water in step (A) is 6:

2.

6. The method for electrochemical synthesis of phenanthridinone and spirocyclic oxindole compounds according to claim 4, characterized in that: In the synthesis method, in step (B), the column chromatography purification is performed with an eluent volume ratio of silica gel: n-hexane / ethyl acetate = 10-20:

1.

7. Use of the phenanthridinone and spirocyclic oxindole compounds or pharmaceutically acceptable salts thereof synthesized by the method of claim 1 in the preparation of anti-tumor drugs.

8. An antitumor drug prepared using the phenanthridone and spirocyclic oxindole compounds or their pharmaceutically acceptable salts synthesized by the method of claim 1 as active ingredients.

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