Electrochemical preparation method for trifluoromethylation / cyclization of fluoroisoquinoline-1,3-dione compounds

Abstract

The present invention belongs to the technical field of synthesis of fluoroisoquinoline-1,3-diketone compounds, and specifically relates to an electrochemical preparation method for trifluoromethylation / cyclization synthesis of fluoroisoquinoline-1,3-diketone compounds. N-alkyl acryloyl aryl formamide, sodium trifluoromethanesulfinate (CF3SO2Na) and electrolyte are dissolved in an organic solvent; electrode materials are selected, and then a constant current is passed through the electrode materials, and the fluoroisoquinoline-1,3-diketone compounds are obtained by reacting at room temperature for 3-6 hours. The method has significant advantages, and does not require the additional addition of expensive and toxic transition metal catalysts and oxidants, ensuring that the electrochemical synthesis method is widely used in the green and diverse construction of trifluoromethylisoquinoline-1,3-diketone derivative synthesis.

Description

Technical Field

[0001] The invention belongs to the technical field of synthesis of fluoroisoquinoline-1,3-dione compounds, and specifically relates to a method for preparing monotrifluoromethyl and bistrifluoromethylisoquinoline-1,3-dione compounds by an electrochemical method in the absence of a catalyst or an oxidant. Background Art

[0002] As the smallest perfluoroalkyl unit, trifluoromethyl (CF3) has the characteristics of strong electron-withdrawing, lipophilicity and stability. Introducing it into the target molecule can usually improve the lipid solubility, bioavailability, metabolic stability, hydrophobicity and binding selectivity of the target molecule. Therefore, compounds containing trifluoromethyl have been widely used in the fields of medicine, pesticides and functional materials (Chem. Soc. Rev. 2008, 37, 320-330). Isoquinoline-1,3-dione derivatives are widely present in natural products and drug compounds and are important skeleton structures of many active molecules. Based on the special properties of trifluoromethyl and the potential medicinal value of isoquinoline-1,3-dione derivatives, it is of great significance to introduce trifluoromethyl groups into the isoquinoline-1,3-dione skeleton. The synthesis and application of this type of compound has become a hot topic for chemists at home and abroad. At present, the methods reported for synthesizing trifluoromethyl isoquinoline-1,3-dione compounds through intermolecular synthesis mainly include: classical oxidation synthesis, visible light catalytic synthesis, and indirect organic electrochemical synthesis. Although these strategies provide effective ways to obtain monotrifluoromethylisoquinoline-1,3-dione, there are some limitations, for example, most reactions involve the use of harmful and expensive transition metal catalysts, stoichiometric oxidants, harsh reaction conditions, etc. Therefore, the development of a mild, green and efficient method to construct monotrifluoromethyl and bistrifluoromethylisoquinoline-1,3-dione has great research and practical value.

[0003] In recent years, electrochemical synthesis has attracted extensive attention from researchers due to its environmental friendliness and superior reaction performance. Compared with traditional synthesis methods, electrochemical synthesis avoids the use of dangerous and toxic redox reagents. Electrochemical methods can generate highly active intermediates (free radicals, radical ions, cations, anions, etc.) through anodic oxidation and cathodic reduction, and are therefore considered to be a green and powerful tool to achieve the construction of covalent bonds between carbon-carbon and carbon-heteroatom. Under this strategy, many biologically active nitrogen-containing heterocycles, such as pyrrolidone, indole, lactam, etc., can achieve CN bond construction through nitrogen-centered free radicals and cationic free radicals formed by anodic oxidation. However, there are few reports on the preparation of mono- and bis-trifluoromethylisoquinoline-1,3-dione compounds by electrochemical methods. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing trifluoromethyl isoquinoline-1,3-dione compounds by electrochemical methods without metal catalysts and oxidants. The method has mild reaction conditions and high reaction efficiency. The preparation of monotrifluoromethyl and bistrifluoromethyl isoquinoline-1,3-dione compounds can be achieved under electrochemical conditions by only regulating the benzyl hydrogen of the benzyl ring part of N-alkyl acryloyl aryl formamide.

[0005] To achieve the above purpose, the technical solution adopted by the present invention comprises the following specific steps:

[0006] An electrochemical preparation method for trifluoromethylation / cyclization synthesis of fluoroisoquinoline-1,3-dione compounds, comprising dissolving N-alkyl acryloyl aryl formamide, sodium trifluoromethanesulfinate (CF3SO2Na) and an electrolyte in an organic solvent, selecting a suitable electrode material, passing a constant current, and reacting at room temperature for 3-6 hours to obtain fluoroisoquinoline-1,3-dione compounds.

[0007] Furthermore, the electrochemical preparation method of a trifluoromethylation / cyclization synthesis of fluoroisoquinoline-1,3-dione compounds is as follows: a trifluoromethyl radical is generated by direct oxidation of a cheap and readily available Langlois reagent (CF3SO2Na) at the anode, and then a free radical addition / cyclization reaction is performed with an N-alkyl acryloyl aryl formamide compound to construct a trifluoromethyl-containing isoquinoline-1,3-dione skeleton structure with a moderate to good yield; when the benzyl ring portion of the N-alkyl acryloyl aryl formamide contains a benzyl hydrogen When the benzyl radical is generated in an oxygen-free atmosphere, it will then couple with the trifluoromethyl radical to generate a compound and introduce CF3 into the benzyl position of the benzyl ring of the isoquinoline-1,3-dione compound; when there is no benzyl hydrogen on the benzyl ring of the N-alkyl acryloyl aryl formamide When , trifluoromethyl isoquinoline-1,3-dione compounds are obtained;

[0008]

[0009] In the formula, when there is no substituent on the benzene ring, R represents H, R 1 represents C1-C4 alkyl, when R 3 When R represents H, R2 and R4 represent H or C1-C2 alkyl respectively. 2 , R 3 , R 4 When neither is H, R represents alkyl, halogen, CF3, or phenyl.

[0010] Furthermore, the equivalent ratio of the N-alkyl acryl aryl formamide to the electrolyte is 1:1-3.

[0011] Furthermore, the equivalent ratio of the N-alkyl acryl aryl formamide to sodium trifluoromethanesulfinate (CF3SO2Na) is 1:1-3.

[0012] Preferably, the electrolyte is any one of Bu4NClO4, LiClO4, Bu4NPF6, Et4NPF6, Et4NBF4, Bu4NBF4, Bu4NOAc, and Et4NOTs.

[0013] Preferably, the organic solvent is any one of MeCN, MeCN / H2O, HFIP / H2O, MeOH, and DMF.

[0014] Preferably, the reaction anode material is any one of reticulated glassy carbon (RVC), carbon rod, carbon sheet, carbon cloth, and platinum sheet (Pt), and the cathode material is any one of Pt, Ni, and RVC.

[0015] Furthermore, the reaction constant current should be controlled at 2-20 mA.

[0016] In summary, due to the adoption of the above technical solution, the beneficial technical effects of the invention are:

[0017] The invention dissolves N-alkyl acryloyl aryl formamide, sodium trifluoromethanesulfinate (CF3SO2Na) and an electrolyte in a corresponding solvent, uses a mesh glassy carbon as an anode and a platinum sheet as a cathode, generates trifluoromethyl radicals (·CF3) by anodic oxidation of CF3SO2Na under the action of a constant reaction current, and ·CF3 adds to the double bond of an unsaturated ketone, further undergoes key reactions such as intramolecular cyclization and free radical addition, and realizes the preparation of mono / bis-trifluoromethylisoquinoline-1,3-dione compounds by an electrochemical method in the absence of a metal catalyst and an oxidant. The invention has mild reaction conditions, high efficiency and convenience, and can realize the preparation of mono / bis-trifluoromethylisoquinoline-1,3-dione compounds under electrochemical conditions by only regulating the benzyl hydrogen of the benzyl ring part of the N-alkyl acryloyl aryl formamide, thereby having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the H NMR spectrum of the final product II-1 in Example 1.

[0019] Figure 2 This is the fluorine spectrum of the final product II-1 in Example 1.

[0020] Figure 3 This is the H NMR spectrum of the final product II-8 in Example 8.

[0021] Figure 4This is the fluorine spectrum of the final product II-8 in Example 8. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and are not used to limit the invention.

[0023] Example 1

[0024] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-1 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cmx0.8cm x1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-1 (42.9mg, 79%) by silica gel chromatography (EA / PE=1;14).

[0025]

[0026] The structural characterization data of compound II-1 are as follows: 1 H NMR (600MHz, CDCl3) δ8.29 (dd, J=7.8, 1.2Hz, 1H), 7.66 (td, J=7.8, 1.2Hz, 1H), 7.48 (ddd, J=8.1, 7.8,1.2Hz,1H),7.42(d,J=7.8Hz,1H),3.41(s,3H),3.37–3.29 (m,1H),2.80(dq,J=15.2,9.8Hz,1H),1.66(s,3H); 13 C NMR(150MHz, CDCl3)δ174.6,163.7,140.4,133.8,129.3,128.0,125.6,125.0(q,J=277.0),124.3,44.4(q,J=28.5Hz,),43.68,43.56(q,J=2.0Hz,), 31.2,27.4; 19 F NMR (375MHz, CDCl3) δ-61.7; HRMS (ESI-TOF) m / z: [M+H] + C 13 H 13 F3NO2 Calcd for 272.0893; Found272.0891.

[0027] Example 2

[0028] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-2 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-2 (38.2mg, 67%) by silica gel chromatography (EA / PE=1;14).

[0029]

[0030] The structural characterization data of compound II-2 are as follows: 1 H NMR (400MHz, CDCl3) δ8.28 (dd, J=7.8, 1.2Hz, 1H), 7.65 (td, J=7.8, 1.2Hz, 1H), 7.47 (ddd, J=8.1, 7.8,1.2Hz,1H),7.41(d,J=8.0Hz,1H),4.010-4.04(m,2H),3.41 –3.29(m,1H),2.84-2.73(m,1H),1.64(s,3H),1.21(t,J=7.2Hz, 3H); 13 C NMR (100MHz, CDCl3) δ174.0,163.2,140.4,133.7,129.3,126.0, 125.6, 125.0 (q, J = 277.1Hz), 124.4, 44.8 ( q, J = 27.4Hz,), 43.4 ( q, J = 2.2Hz), 35.9, 31.2, 12.7; 19 F NMR (375MHz, CDCl3) δ-61.5; HRMS (ESI-TOF) m / z: [M+Na] + C 14 H 14 F3NNaO2 Calcd for308.0869; Found 308.0867.

[0031] Example 3

[0032] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-3 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-3 (41mg, 70%) by silica gel chromatography (EA / PE=1;14).

[0033]

[0034] The structural characterization data of compound II-3 are as follows: 1 H NMR (400MHz, CDCl3) δ8.27 (dd, J=7.8, 1.2Hz, 1H), 7.64 (td, J=7.8, 1.2Hz, 1H), 7.47 (td, J=8.0, 0.8 Hz,1H),7.41(d,J=8.0Hz,1H),4.02–3.93(m,2H),3.42–3.29(m,1H),2.85-2.74(m,1H),1.67–1.61(m,5H),0.95(t,J=7.2Hz,3H); 13 C NMR (100MHz, CDCl3) δ174.2,163.4,140.4,133.7,129.3,126.4, 125.6,125.0(q,J=277.0Hz),124.3,44.1(q,J=27.2Hz),43.5(q,J= 2.0Hz),42.3,31.4,20.8,11.3; 19 F NMR (375MHz, CDCl3) δ-61.4; HRMS (ESI-TOF) m / z: [M+Na] + C 15 H 16 F3NNaO2 Calcdfor 322.1025; Found 322.1023.

[0035] Example 4

[0036] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-4 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cmx0.8cm x1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-4 (42.4mg, 71%) by silica gel chromatography (EA / PE=1;14).

[0037]

[0038] The structural characterization data of compound II-4 are as follows: 1 H NMR (400MHz, CDCl3) δ8.25 (dd, J=7.8, 1.2Hz, 1H), 7.65–7.60 (td, J=7.8, 1.2Hz ,1H),7.46(td,J=8.0,1.2Hz,1H),7.38(d,J=7.6Hz,1H),5.22(hept,J=6.8Hz, 1H),3.39-3.27(m,1H),2.81-2.70(m,1H),1.63(s,3H),1.47(dd, J=6.8,4.0Hz,6H); 13 C NMR (100MHz, CDCl3) δ174.4,163.8,140.3,133.5, 129.3,127.2,126.5,125.4(q,J=277.0),124.9,44.9,(q,J=27.2Hz), 43.8(q,J=2.2Hz),31.1,19.33,19.31; 19 F NMR (375MHz, CDCl3) δ-61.4; HRMS (ESI-TOF) m / z: [M+Na] + C 15 H 16 F3NNaO2Calcd for 322.1025; Found 322.1028.

[0039] Example 5

[0040] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-5 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-5 (39.5mg, 63%) by silica gel chromatography (EA / PE=1;14).

[0041]

[0042] The structural characterization data of compound II-5 are as follows: 1 H NMR (400MHz, CDCl3) δ8.27 (dd, J=7.8, 1.2Hz, 1H), 7.65 (td, J=7.8, 1.2Hz, 1H), 7.47 (td, J=8.0, 1.2 Hz,1H),7.41(d,J=8.0Hz,1H),4.04–3.96(m,2H),3.42-3.30(m,1H),2.85-2.74(m,1H),1.64(s,3H),1.61-1.55(m,2H),1.42–1.35 (m,2H),0.94(t,J=7.2Hz,3H); 13 C NMR (100MHz, CDCl3) δ174.2,163.4, 140.4,133.7,129.3,127.98,125.6,125.0(q,J=277.0),124.3,44.2(q, J=27.6Hz), 43.5(q, J=2.0Hz), 40.6, 31.4, 29.6, 20.2, 13.7; 19 F NMR (375MHz, CDCl3) δ-61.4; HRMS (ESI-TOF) m / z: [M+Na] + C 16 H 18 F3NNaO2 Calcd for 336.1182; Found 336.1183.

[0043] Example 6

[0044] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-6 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-6 (42.6mg, 65%) by silica gel chromatography (EA / PE=1;14).

[0045]

[0046] The structural characterization data of compound II-6 are as follows: 1 H NMR (400MHz, CDCl3) δ8.28(d,J=2.0Hz,1H),7.68(dd,J=8.0,2.0Hz,1H),7.33(d,J=8.0Hz,1H), 3.40(s,3H),3.35–3.26(m,1H),2.78-2.73(m,1H),1.63(s,3H), 1.36(s,9H); 13 C NMR (100MHz, CDCl3) δ174.8,164.1,151.3,137.4,131.2, 125.8,125.4,125.0(q,J=277.0Hz),123.7,44.3(q,J=27.6Hz),43.3 (q,J=2.0Hz),34.8,31.14,31.19,27.4. 19 F NMR (375MHz, CDCl3) δ-61.6; HRMS (ESI-TOF) m / z: [M+Na] + C 17 H 20 F3NNaO2Calcd for 350.1338; Found 350.1333.

[0047] Example 7

[0048] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-7 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-7 (50.7mg, 73%) by silica gel chromatography (EA / PE=1;14).

[0049]

[0050] The structural characterization data of compound II-7 are as follows: 1 H NMR (400MHz, CDCl3) δ8.52 (d, J=2.0Hz, 1H), 7.89 (dd, J=8.0, 2.0Hz, 1H), 7.68-7.65 (m, 2H), 7.50 -7.47(m,3H),7.43–7.38(m,1H),3.44(s,3H),3.42-3.33(m,1H), 2.84(m,1H),1.69(s,3H); 13 C NMR (100MHz, CDCl3) δ174.5,163.7,141.1, 139.0,132.3,129.0,128.2,127.5,127.1,126.2,125.0(q,J=277.0Hz),124.6,123.6,44.3(q,J=27.2Hz,1H),43.3(q,J=2.0Hz),31.2, 27.5; 19 F NMR (375MHz, CDCl3) δ-61.5; HRMS (ESI-TOF) m / z: [M+Na] + C 19 H 16 F3NNaO2 Calcd for 370.1025; Found370.1026.

[0051] Example 8

[0052] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-8 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-8 (37.4mg, 53%) by silica gel chromatography (EA / PE=1;14).

[0053]

[0054] The structural characterization data of compound II-8 are as follows: 1 H NMR (400MHz, CDCl3) δ8.22(d,J=1.6Hz,1H),7.60(dd,J=8.0,1.6Hz,1H),7.43(d,J=8.0Hz,1H), 3.47(q,J=10.8Hz,2H),3.41(s,3H),3.39-3.30(m,1H),2.84-2.73(m,1H),1.66(s,3H); 13 C NMR (100MHz, CDCl3) δ174.3,163.3,140.3, 135.3,130.9,130.4(q,J=2.9Hz),126.2,125.0(q,J=277.0Hz),124.6,123.5,44.3(q,J=27.5Hz),43.4(q,J=2.0Hz),39.7(q,J=30.1 Hz),31.0,27.5; 19 F NMR(375MHz, CDCl3)δ-61.7,-65.8; HRMS(ESI-TOF) m / z:[M+Na] + C 15 H 13 F6NNaO2 Calcd for376.0743; Found 376.0748.

[0055] Example 9

[0056] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-9 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-9 (40mg, 55%) by silica gel chromatography (EA / PE=1;14).

[0057]

[0058] The structural characterization data of compound II-9 are as follows: 1 H NMR (400MHz, CDCl3) δ8.24 (dd, J=11.2, 1.6Hz, 1H), 7.64-7.59 (m, 1H), 7.42 (dd, J=8.2, 4.6Hz, 1H), 3.62–3.48(m,1H),3.40(s,3H),3.34-3.29(m,1H),2.84-2.73(m,1H),1.65(s,3H),1.56(dd,J=7.2,5.2Hz,3H); 19 F NMR (376MHz, CDCl3) δ-61.7,-71.5; HRMS (ESI-TOF) m / z: [M+Na] + C 16 H 15 F6NNaO2 Calcd for390.0899; Found 390.0909.

[0059] Example 10

[0060] Into a 10mL three-necked round-bottom flask, accurately weigh the substrate I-10 (0.2mmol), LiClO4 (0.4mmol, 43mg) and sodium trifluoromethanesulfinate (0.6mmol, 93.6mg), RVC (1.2cm x 0.8cm x 1.0cm) as the anode and a platinum plate (1cm×1mm) as the cathode, add bottled and oxygen-free MeCN (5.0mL) in an argon atmosphere, pass a constant current of 3mA and electrolyze at room temperature for 4.5h. After the reaction is completed, concentrate under reduced pressure and obtain the desired target compound II-10 (46.5mg, 61%) by silica gel chromatography (EA / PE=1;14).

[0061]

[0062] The structural characterization data of compound II-10 are as follows: 1 H NMR (400MHz, CDCl3) δ8.40(d,J=1.6Hz,1H),7.79(dd,J=8.4,1.2Hz,1H),7.41(d,J=8.4Hz,1H), 3.41(s,3H),3.38–3.29(m,1H),2.85–2.74(m,1H),1.66(s,3H), 1.64(d,J=5.9Hz,6H); 19 FNMR (375MHz, CDCl3) δ-61.6,-76.2; HRMS (ESI-TOF) m / z: [M+Na] + C 17 H 17 F6NNaO2 Calcd for 404.1056; Found 404.1067.

[0063] The above description is a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the invention should be included in the protection scope of the invention.

Claims

1. An electrochemical preparation method for trifluoromethylation / cyclization of fluoroisoquinoline-1,3-dione compounds, characterized in that: Dissolve N-alkyl acryloyl aryl formamide, sodium trifluoromethanesulfinate (CF3SO2Na) and electrolyte in an organic solvent; select electrode materials, then pass a constant current through the electrode materials, and react at room temperature for 3-6 hours to obtain fluoroisoquinoline-1,3-dione compounds; The electrolyte is LiClO4; The organic solvent MeCN; The reaction anode material is reticulated glassy carbon (RVC), and the cathode material is Pt; R 1 is C1-C4 alkyl, R 4 For H, R 2 、 R 3 Independently selected from H or C1-C2 alkyl.

2. The electrochemical preparation method of a trifluoromethylation / cyclization synthesis of fluoroisoquinoline-1,3-dione compounds according to claim 1, characterized in that: The equivalent ratio of the N-alkyl acryl aryl formamide to the electrolyte is 1:1-3.

3. The electrochemical preparation method of a trifluoromethylation / cyclization synthesis of fluoroisoquinoline-1,3-dione compounds according to claim 1, characterized in that: The equivalent ratio of the N-alkyl acryloyl aromatic formamide to sodium trifluoromethanesulfinate (CF3SO2Na) is 1:1-3.

4. The electrochemical preparation method of a trifluoromethylation / cyclization synthesis of fluoroisoquinoline-1,3-dione compounds according to claim 1, characterized in that: The reaction constant current should be controlled at 2-20 mA.

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