A benzoxazinone derivative and a method for synthesizing the same

Abstract

This invention belongs to the field of organic synthesis technology, specifically relating to a benzoxazinone derivative and its synthetic method. The synthetic method uses acylindole, oxygen, and p-fluorothiophenol as reactants, and synthesizes the derivative via a photochemical reaction. The method employs a one-pot, visible light-driven H-EDA donor-catalyzed reaction in a metal-free and chemically oxidizing integrated tank to construct the benzoxazinone derivative. Compared to previously reported synthetic methods, this invention is simpler to operate, has broader substrate applicability, and is compatible with aryl, alkyl, and pharmaceutical macromolecule substrates; the reaction does not require heating, effectively improving the safety of the production process; the raw materials used are inexpensive and readily available, the synthesis efficiency is high, and the yield of the target product is excellent; the yield remains high even after scale-up. Furthermore, this method has good atom economy, requiring no addition of stoichiometric oxidants, and only a catalytic amount of thiol is needed to complete the conversion, making it suitable for large-scale industrial production and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a benzoxazinone derivative and its synthesis method. Background Technology

[0002] Electron donor-acceptor (EDA) complex photochemistry is a core area of ​​organic photocatalytic synthesis. Since its proposal in 1950, it has been widely believed that its excited-state reaction pathway uniquely follows a single-electron transfer (SET) mechanism: the donor and acceptor mix to form a ground-state aggregate, which, upon photoexcitation, generates a charge-transfer state, leading to thermodynamically feasible electron transfer and the generation of free radical ion pairs, thus becoming an important tool for free radical synthesis and drug molecule construction. However, this mechanism has significant limitations: when the HOMO-LUMO energies of the donor and acceptor are close and the electron transfer is a thermodynamic uphill process (ΔGET>0), the SET pathway cannot proceed at all, greatly limiting the application scenarios of EDA catalysis.

[0003] Meanwhile, skeletal editing, as a cutting-edge strategy for precise structural modification of organic molecules, has attracted much attention in the modification of heterocyclic compounds. Indole, as one of the most advantageous skeletal components in natural products and drug molecules, allows for rapid structure-activity relationship studies and the construction of novel pharmacophores through skeletal remodeling techniques such as atomic insertion and carbon-nitrogen exchange. Among these, the selective C2 carbon deletion of acylindole, accompanied by ring expansion to generate highly active benzoxazinones, represents a highly valuable transformation in medicinal chemistry, but previously lacked effective methods. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention provides the following technical solution: In a first aspect, a benzoxazinone derivative is provided, the structure of which is shown in formula (23e), formula (25e), or formula (26e): .

[0005] Secondly, a method for synthesizing benzoxazinone derivatives is provided. The method uses an N-acylindole compound (Formula I) as a starting substrate and, in an organic solvent system under an oxygen atmosphere, uses p-fluorothiophenol as a catalyst to obtain an intermediate via photoreaction. Then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCl) is introduced for condensation cyclization to obtain the benzoxazinone derivative (Formula II). The synthetic route is selected from any of the following: Route 1: Route 2: Route 3: .

[0006] In the above synthesis methods, the substituent group represented by R1 in routes one to three has the same meaning. R1 is selected from hydrogen, C1-C4 alkyl, and halogen. Further, the alkyl is methyl, and the halogen is chlorine or bromine. In some embodiments verified by the present invention, R1 is selected from hydrogen atom, 4-methyl, 5-methyl, 5-chlorine, or 5-bromine.

[0007] In Route 1, R2 is selected from alkyl, aryl, heteroaryl, or alkoxy groups; further, R2 is selected from C1-C6 groups with substituted or unsubstituted functional groups. 20 Alkyl groups, C6-C with substituted or unsubstituted functional groups 20 C3-C of aryl, substituted or unsubstituted functional groups 20 C1-C of heteroaryl, substituted or unsubstituted functional groups 20 Any of the alkoxy groups includes both straight-chain and branched substitutions, and the functional group is selected from one or more of alkyl, halogen, alkoxy, acyloxy, aryl, aryloxy, and sulfonamide groups. In some embodiments verified by the present invention, the alkyl group is selected from methyl, tert-butyl, benzyl, phenyl, p-methylphenyl, p-tert-butylphenyl, m-methylphenyl, m-chlorophenyl, o-methylphenyl, o-iodophenyl, o-bromophenyl, 2-naphthyl, 2-thienyl, p-N,N-dipropylaminosulfonylphenyl, o-methoxyphenyl, hexadecyloxy, n-heptadecyl, p-acetoxyphenyl, 2-propylpentyl, phenethyl, (4-chloro-2-methylphenoxy)-methyl, 2-(4-(4-chlorobenzoyl)phenoxy)-2-propyl.

[0008] In Route 2, R3 is selected from ethyl, unsubstituted aryl, or halogen-substituted aryl; in some embodiments verified by the present invention, R3 is selected from ethyl, phenyl, or p-fluorophenyl (4-fluorophenyl).

[0009] In Route 3, R4 is a C1-C4 alkyl group, and in some embodiments verified by this invention, R4 is a methyl group.

[0010] Furthermore, the above synthesis method also has the following preferred embodiments: The molar ratio of the N-acylindole compound, oxygen, p-fluorothiophenol and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is 0.8~1.2:0.1~0.3:0.8~1.2:0.8~2.2.

[0011] Furthermore, the organic solvent is acetonitrile.

[0012] Furthermore, the photoreaction is performed at room temperature, using blue light with a wavelength of 380-400 nm and an illumination time of 15-25 hours.

[0013] Furthermore, after the above condensation cyclization, the reaction system should be extracted and separated by column chromatography to obtain the corresponding benzoxazinone derivative. The extraction reagent is water and ethyl acetate in a volume ratio of 0.8~1.2:0.8~1.2. After extraction, the organic phase is retained and concentrated. The column chromatography separation uses silica gel column chromatography to separate the crude product, and the elution solvent is a mixture of petroleum ether and ethyl acetate.

[0014] Compared with the prior art, the beneficial effects of the present invention are: The compounds synthesized in this invention exhibit excellent pharmaceutical activity. This invention provides a method for synthesizing benzoxazinone derivatives. The method utilizes readily available acylindole and oxygen as raw materials under simple and mild light conditions to achieve a one-pot visible light-driven H-EDA donor-catalyzed reaction to construct benzoxazinone derivatives. The synthesis method is mild, yielding the target product with high selectivity at room temperature and under oxygen conditions. It offers advantages such as simple operation, readily available and inexpensive raw materials, broad substrate applicability, high synthesis efficiency, and high atom economy. The compounds synthesized in this invention possess excellent pharmaceutical activity and can be used in the preparation of bioactive molecules and clinical drugs, showing promising application prospects. Detailed Implementation

[0015] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0016] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0017] In the context of this invention, the word "comprising" is considered to mean "particularly including". It should not be interpreted as "consisting of only".

[0018] In the description of this invention, it should be understood that the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The symbol " / " in this document indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0019] In the description of embodiments of the present invention, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0020] In the description of the embodiments of the present invention, unless otherwise stated, "a plurality of" means two or more. To enable those skilled in the art to more clearly understand the technical solutions of the present invention, the technical solutions of the present invention will be described in detail below with reference to specific embodiments.

[0021] Example 1 In this embodiment, a method for synthesizing o-acetamide benzoic acid lactone (CAS: 525-76-8) is provided, the structure of which is shown in formula (1e): (1e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-acetylindole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 1e (human leukocyte elastase inhibitors), with a separation yield of 93%.

[0022] MRI: 1 H NMR (500 MHz, CDCl3): δ 8.16 (dd, J = 7.9, 1.2 Hz, 1H), 7.80 –7.73 (m, 1H), 7.52 (d, J = 8.0 Hz, 1H), 7.53 – 7.45 (m, 1H), 2.45 (s, 3H). 13CNMR (126 MHz, CDCl3): δ 160.4, 159.7, 146.4, 136.6, 128.5, 128.2, 126.4,116.7, 21.2. Example 2 In this embodiment, a method for synthesizing 3-tert-Butyl-3-hydroxy-2,3-dihydroindol-2-one (CAS: 53904-04-4) is provided, the structure of which is shown in formula (2e): (2e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-neovalerylindole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 2e (inhibitors of human leukocyte elastase) with a yield of 60%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.18 (dd, J = 7.8, 1.6 Hz, 1H), 7.78 (ddd, J = 8.1, 7.3, 1.6 Hz, 1H), 7.58 (dd, J = 8.1, 1.4 Hz, 1H), 7.48 (td, J= 7.6, 1.2 Hz, 1H), 1.40 (s, 9H). 13 C NMR (126 MHz, CDCl3): δ 168.4, 160.2,146.7, 136.4, 128.4, 128.1, 127.0, 116.9, 38.1, 27.8. Example 3 In this embodiment, a 2-(Phenylmethyl)-4 H A method for synthesizing 3,1-benzoxazin-4-one (CAS: 58980-13-5), the structure of which is shown in formula (3e): (3e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-phenylacetylindole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 3e (inhibitors of human leukocyte elastase) with a yield of 75%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.13 (dd, J = 7.8, 1.5 Hz, 1H), 7.78 –7.71 (m, 1H), 7.55 (dd, J = 8.1, 1.1 Hz, 1H), 7.46 (td, J = 7.6, 1.2 Hz, 1H),7.42 – 7.37 (m, 2H), 7.32 (dd, J = 8.3, 6.6 Hz, 2H), 7.29 – 7.22 (m, 1H),3.95 (s, 2H). 13 C NMR (126 MHz, CDCl3): δ 161.2, 159.6, 146.5, 136.5, 134.3,129.3, 128.9, 128.5, 128.4, 127.5, 126.9, 116.9, 41.7. Example 4 In this embodiment, a method for synthesizing 2-phenyl-3,1-benzoxazin-4-one (CAS: 1022-46-4) is provided, the structure of which is shown in formula (4e): (4e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-benzoylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to give 4e (bentrani) with a yield of 85%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.30 (d, J = 7.5 Hz, 2H), 8.26 – 8.20(m, 1H), 7.85 – 7.78 (m, 1H), 7.68 (d, J = 8.1 Hz, 1H), 7.57 (t, J = 7.3 Hz,1H), 7.50 (t, J = 7.5 Hz, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.6, 157.2, 147.1,136.6, 132.7, 130.3, 128.8, 128.7, 128.4, 128.3, 127.3, 117.1. Example 5 In this embodiment, a method for synthesizing 2-(p-tolyl)-3,1-benzoxazin-4(4h)-one (CAS: 18600-54-9) is provided, the structure of which is shown in formula (5e): (5e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-toluamide indole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, 2.0 mL of acetonitrile and 0.05 mmol of p-fluorothiophenol were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 5e (α-Chymotrypsin inhibition), with a yield of 59%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.22 (dd, J = 8.0, 1.6 Hz, 1H), 8.21 –8.16 (m, 2H), 7.80 (ddd, J = 8.6, 7.3, 1.6 Hz, 1H), 7.66 (d, J = 8.6 Hz, 1H), 7.49 (td, J = 7.5, 1.2 Hz, 1H), 7.30 (d, J = 8.1 Hz, 2H), 2.43 (s, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.8, 157.4, 147.2, 143.5, 136.6, 129.6, 128.6, 128.4,128.1, 127.5, 127.2, 117.1, 21.8. Example 6 In this embodiment, a method for synthesizing 2-(4-tert-butylphenyl)-4H-3,1-benzoxazin-4-one (CAS: 117145-55-8) is provided, the structure of which is shown in formula (6e): (6e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(4-tert-butylbenzoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 6e (Hypolipidemic), with a yield of 65%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.26 – 8.21 (m, 3H), 7.82 (ddd, J =8.6, 7.3, 1.6 Hz, 1H), 7.69 (dd, J = 8.1, 1.1 Hz, 1H), 7.53 (dd, J = 8.8, 2.1Hz, 2H), 7.49 (dd, J = 7.6, 1.2 Hz, 1H), 1.37 (s, 9H). 13 C NMR (126 MHz, CDCl3): δ 159.9, 157.4, 156.5, 147.3, 136.6, 128.7, 128.3, 128.1, 127.5, 127.2, 125.9, 117.1, 35.2, 31.2. Example 7 In this embodiment, a method for synthesizing 2-(3-methylphenyl)-3,1-benzoxazin-4-one (CAS: 82525-38-0) is provided, the structure of which is shown in formula (7e): (7e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(m-methylbenzoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 7e (α-Chymotrypsinin inhibition), with a yield of 68%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.13 (dd, J = 7.9, 1.5 Hz, 1H), 8.03 –7.97 (m, 2H), 7.74 – 7.67 (m, 1H), 7.60 – 7.55 (m, 1H), 7.40 (t, J = 7.6 Hz,1H), 7.28 (d, J = 6.9 Hz, 2H), 2.34 (s, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.7,157.3, 147.1, 138.6, 136.6, 133.5, 130.2, 128.8, 128.7, 128.6, 128.2, 127.2,125.6, 117.1, 21.4. Example 8 In this embodiment, a method for synthesizing 2-(3-chlorophenyl)-benzo[d][1,3]oxazin-4-one (CAS: 35067-68-6) is provided, the structure of which is shown in formula (8e): Equation (8e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(m-chlorobenzoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 8e (α-Chymotrypsin inhibition), with a yield of 62%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.29 (t, J = 1.9 Hz, 1H), 8.23 ​​(dd, J= 7.8, 1.5 Hz, 1H), 8.17 (dt, J = 7.8, 1.4 Hz, 1H), 7.87 – 7.79 (m, 1H), 7.69(dd, J = 8.3, 1.1 Hz, 1H), 7.53 (tt, J = 6.4, 1.6 Hz, 2H), 7.44 (t, J = 7.9Hz, 1H). 13 C NMR (126 MHz, CDCl3): δ 159.2, 155.9, 146.7, 136.8, 135.1, 132.6,132.1, 130.1, 128.8, 128.7, 128.4, 127.4, 126.4, 117.1. Example 9 In this embodiment, a method for synthesizing 2-(2-methylphenyl)-4H-3,1-benzoxazin-4-one (CAS: 18595-87-4) is provided, the structure of which is shown in formula (9e): Equation (9e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(o-methylbenzoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 9e (α-Chymotrypsinin inhibition) with a yield of 55%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.26 (dd, J = 7.8, 1.5 Hz, 1H), 8.03 (dd, J = 7.7, 1.7 Hz, 1H), 7.84 (td, J = 7.7, 1.6 Hz, 1H), 7.70 (dd, J = 8.1,1.1 Hz, 1H), 7.54 (td, J = 7.6, 1.2 Hz, 1H), 7.43 (td, J = 7.5, 1.5 Hz, 1H), 7.33 (t, J = 7.6 Hz, 2H), 2.74 (s, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.9,158.4, 146.9, 139.3, 136.6, 132.0, 131.7, 130.2, 129.9, 128.6, 128.5, 127.4,126.2, 116.9, 22.2. Example 10 In this embodiment, a method for synthesizing 4H-3,1-Benzoxazin-4-one, 2-(2-iodophenyl)-2-(2-Iodophenyl)-4H-3,1-benzoxazin-4-one (CAS: 176442-54-9) is provided, the structure of which is shown in formula (10e): Equation (10e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(o-iodobenzoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 10e (C1r serine protease inhibitor) with a yield of 45%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.28 (dd, J = 7.8, 1.5 Hz, 1H), 8.04 (dd, J = 8.0, 1.1 Hz, 1H), 7.91 – 7.81 (m, 2H), 7.75 (dd, J = 8.0, 1.2 Hz, 1H), 7.59 (td, J = 7.6, 1.2 Hz, 1H), 7.49 (td, J = 7.6, 1.2 Hz, 1H), 7.20 (td, J = 7.7, 1.7 Hz, 1H). 13 C NMR (126 MHz, CDCl3): δ 159.4, 157.9, 146.3,141.2, 136.8, 135.6, 132.4, 131.0, 129.1, 128.7, 128.3, 127.5, 117.1, 94.7. Example 11 In this embodiment, a method for synthesizing 2-(2-bromophenyl)-4H-3,1-benzoxazin-4-one (CAS: 18595-86-3) is provided, the structure of which is shown in formula (11e): Equation (11e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(o-bromobenzoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 11e (α-Chymotrypsin inhibition), with a yield of 60%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.28 (dd, J = 7.8, 1.5 Hz, 1H), 7.87 (td, J = 7.5, 1.6 Hz, 2H), 7.73 (dd, J = 8.1, 1.3 Hz, 2H), 7.59 (td, J = 7.6,1.2 Hz, 1H), 7.45 (td, J = 7.6, 1.2 Hz, 1H), 7.38 (td, J = 7.7, 1.8 Hz, 1H). 13 C NMR (126 MHz, CDCl3): δ 159.3, 157.3, 146.5, 136.8, 134.4, 132.5,132.4,131.6, 129.1, 128.7, 127.6, 127.5, 121.9, 117.1. Example 12 In this embodiment, a 2-(2-Naphthalenyl)-4 H -3,1-benzoxazin-4-one (CAS: 85179-17-5 The method for synthesizing the compound, the structure of which is shown in formula (12e): Equation (12e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(2-naphthoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 12e (human leukocyte elastase inhibitor) with a yield of 64%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.83 (s, 1H), 8.37 (dd, J = 8.7, 1.8Hz, 1H), 8.26 (dd, J = 7.9, 1.2 Hz, 1H), 8.00 (d, J = 7.9 Hz, 1H), 7.95 (d, J= 8.7 Hz, 1H), 7.89 (d, J = 8.0 Hz, 1H), 7.84 (ddd, J = 8.2, 7.4, 1.5 Hz,1H), 7.77 – 7.67 (m, 1H), 7.67 – 7.49 (m, 3H). 13 C NMR (126 MHz, CDCl3): δ159.8, 157.3, 147.2, 136.7, 135.4, 132.9, 129.6, 129.5, 128.7, 128.7, 128.4,128.4, 127.9, 127.5, 127.4, 127.0, 124.2, 117.1. Example 13 In this embodiment, a method for synthesizing 2-(thiophene-2-yl)-4H-benzo[D][1,3]oxazin-4-one (CAS: 26060-06-0) is provided, the structure of which is shown in formula (13e): Equation (13e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(2-thiophenecarboxyl)indole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 13e (A1 adenosine receptors) with a yield of 41%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.22 (dd, J = 7.9, 1.5 Hz, 1H), 7.97 (dd, J = 3.8, 1.2 Hz, 1H), 7.80 (ddd, J = 8.4, 7.3, 1.5 Hz, 1H), 7.66 – 7.59(m, 2H), 7.49 (td, J = 7.6, 1.2 Hz, 1H), 7.17 (dd, J = 5.0, 3.8 Hz, 1H). 13 CNMR (126 MHz, CDCl3): δ 159.2, 153.8, 147.2, 136.8, 134.3, 132.5, 131.9,128.8, 128.5, 128.1, 127.0, 116.8. Example 14 In this embodiment, a 4-(4-Oxo-4) H -3,1-benzoxazin-2-yl)- N , N The method for synthesizing 1-dipropylbenzenesulfonamide (CAS: 905550-04-1), the structure of which is shown in formula (14e): Equation (14e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 4-(1-indolecarboxyl)-N,N-dipropylbenzenesulfonamide was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 14e, with a yield of 63%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.46 – 8.41 (m, 2H), 8.26 (dd, J =7.8, 1.5 Hz, 1H), 7.97 – 7.92 (m, 2H), 7.90 – 7.83 (m, 1H), 7.73 (dd, J =8.1, 1.1 Hz, 1H), 7.57 (td, J = 7.6, 1.2 Hz, 1H), 3.17 – 3.10 (m, 4H), 1.56(h, J = 7.4 Hz, 4H), 0.88 (t, J = 7.4 Hz, 6H). 13 C NMR (126 MHz, CDCl3): δ159.1, 155.7, 146.6, 143.9, 136.9, 133.8, 129.1, 128.9, 128.9, 127.6, 127.4,117.2, 50.0, 22.0, 11.3. Example 15 In this embodiment, a method for synthesizing 2,5-dimethyl-3,1-benzoxazin-4-one (CAS: 60288-19-9) is provided, the structure of which is shown in formula (15e): Equation (15e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-acetyl-4-methylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 15e (elastase inhibition), with a yield of 46%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 7.54 (t, J = 7.8 Hz, 1H), 7.29 (d, J =7.9 Hz, 1H), 7.19 (d, J = 7.5 Hz, 1H), 2.71 (s, 3H), 2.35 (s, 3H). 13 C NMR (126MHz, CDCl3): δ 160.3, 159.0, 147.8, 142.9, 135.7, 130.7, 124.3, 115.2, 22.6,21.1. Example 16 In this embodiment, a method for synthesizing 6-methyl-2-phenyl-4H-3,1-benzoxazin-4-one (CAS: 117039-85-7) is provided, the structure of which is shown in formula (16e): Equation (16e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic magnet and 0.25 mmol of 1-benzoyl-5-methylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 16e (hypolipidemi) with a yield of 75%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.31 – 8.26 (m, 2H), 8.02 (s, 1H), 7.62 (dd, J = 8.3, 2.1 Hz, 1H), 7.58 (d, J = 8.1 Hz, 1H), 7.56 – 7.53 (m,1H), 7.52 – 7.46 (m, 2H), 2.48 (s, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.8,156.5, 144.9, 138.8, 137.9, 132.5, 130.4, 128.8, 128.3, 128.2, 19 127.1,116.8, 21.4. Example 17 In this embodiment, a method for synthesizing 2,6-dimethyl-4H-3,1-benzoxazin-4-one (CAS: 62175-49-9) is provided, the structure of which is shown in formula (17e): Equation (17e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-acetyl-5-methylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 17e (elastase inhibition), with a yield of 34%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 7.97 (s, 1H), 7.59 (dd, J = 8.2, 1.8Hz, 1H), 7.44 (d, J = 8.2 Hz, 1H), 2.46 (d, J = 4.2 Hz, 6H). 13 C NMR (126 MHz, CDCl3): δ 160.0, 159.6, 144.3, 138.7, 137.9, 128.1, 126.2, 116.4, 21.3, 21.3. Example 18 In this embodiment, a method for synthesizing 6-Chloro-2-(2-methoxyphenyl)-4H-3,1-benzoxazin-4-one (CAS: 692290-72-5) is provided, the structure of which is shown in formula (18e): Equation (18e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(2-methoxybenzoyl)-5-chloroindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 18e, with a separation yield of 85%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.20 (d, J = 2.4 Hz, 1H), 7.87 (dd, J= 7.7, 1.8 Hz, 1H), 7.75 (dd, J = 8.6, 2.4 Hz, 1H), 7.64 (d, J = 8.6 Hz, 1H), 7.51 (ddd, J = 8.4, 7.4, 1.8 Hz, 1H), 7.10 – 7.01 (m, 29 2H), 3.94 (s, 3H). 13 CNMR (126 MHz, CDCl3): δ 158.9, 158.0, 145.7, 136.8, 134.0, 133.6, 131.5,128.9, 127.9, 120.7, 120.2, 118.1, 112.3, 56.2. High resolution: HRMS (ESI) m / z: [M+H] + calcd for C 15 H 10 ClNO3: 288.0422; found:288.0423. Example 19 In this embodiment, a method for synthesizing 6-bromo-2-(4-tert-butylphenyl)-3,1-benzoxazin-4-one (CAS: 117145-51-4) is provided, the structure of which is shown in formula (19e): Equation (19e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-(4-tert-butylbenzoyl)-5-bromoindole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 19e (Hypolipidemic), with a separation yield of 87%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.34 (d, J = 2.3 Hz, 1H), 8.20 (d, J =8.6 Hz, 2H), 7.88 (dd, J = 8.6, 2.3 Hz, 1H), 7.53 (dd, J = 11.8, 8.6 Hz, 3H),1.37 (s, 9H). 13 C NMR (126 MHz, CDCl3): δ 158.5, 157.7, 156.9, 146.1, 139.7,131.1, 128.9, 128.4, 127.1, 125.9, 121.2, 118.4, 35.3, 31.2. Example 20 In this embodiment, a method for synthesizing 2-hexadecyloxy-6-methyl-4H-3,1-benzoxazin-4-one (CAS: 282526-98-1) is provided, the structure of which is shown in formula (20e): Equation (20e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 1-hexadecyloxycarbonyl-5-methylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to give 20e (Cetilistat) with a yield of 68%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 7.90 (d, J = 2.0 Hz, 1H), 7.52 (dd, J= 8.3, 2.1 Hz, 1H), 7.31 (d, J = 8.2 Hz, 1H), 4.42 (t, J = 6.6 Hz, 2H), 2.42(s, 3H), 1.85 – 1.75 (m, 2H), 1.44 (td, J = 9.1, 8.4, 4.9 Hz, 2H), 1.26 (s,24H), 0.88 (t, J = 6.8 Hz, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.8, 154.6,146.3, 138.1, 135.9, 128.6, 125.2, 114.3, 70.1, 32.0, 29.8, 29.8, 29.7, 29.7,29.6, 29.5, 29.3, 28.5, 25.8, 22.8, 21.0, 14.2. Example 21 In this embodiment, a 2-Heptadecyl-4 is provided. H A method for synthesizing 3,1-benzoxazin-4-one (CAS: 16062-70-7), the structure of which is shown in formula (21e): Equation (21e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-octadecanoylindole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 21e, with a yield of 70%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.19 (dd, J = 7.9, 1.5 Hz, 1H), 7.79(td, J = 7.7, 1.6 Hz, 1H), 7.56 (d, J = 8.1 Hz, 1H), 7.53 – 7.46 (m, 1H), 2.71 –2.65 (m, 2H), 1.82 (p, J = 7.6 Hz, 2H), 1.25 (s,28H), 0.88 (t, J = 6.8 Hz, 3H). 13 CNMR (126 MHz, CDCl3): δ 163.4, 160.0, 146.6, 136.6, 128.5, 128.2, 126.7,117.0, 35.0, 32.0, 29.8, 29.8, 29.8, 29.8, 29.7, 29.7, 29.5, 29.5, 29.3,29.2, 26.3, 22.8, 14.2. Example 22 In this embodiment, a method for synthesizing 4-(4-oxo-4H-3,1-benzoxazin-2-yl)phenyl acetate (CAS:298682-51-6) is provided, the structure of which is shown in formula (22e) below: Equation (22e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of 4-(1-indolecarboxyl)phenylacetate was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 0.5 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 22e (fireflyluciferase inhibitor) with a yield of 70%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.30 – 8.21 (m, 2H), 7.86 – 7.80 (m,1H), 7.64 (d, J = 8.1 Hz, 1H), 7.59 (td, J = 7.8, 1.7 Hz, 1H), 7.54 (t, J = 7.6 Hz, 1H), 7.41 (t, J = 7.7 Hz, 1H), 7.19 (d, J = 8.1 Hz, 1H), 2.46 (s, 3H). 13 C NMR (126MHz, CDCl3): δ 169.9, 159.1, 155.3, 150.0, 146.7, 136.7, 133.5, 131.2, 128.8,128.7, 127.3, 126.5, 124.5, 123.5, 117.1, 21.2. Example 23 In this embodiment, a method for synthesizing a benzoxazinone derivative is provided, the structure of which is shown in formula (23e): Equation (23e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-(2-propylpentanoyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 23e, with a separation yield of 85%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.19 (dd, J = 7.9, 1.5 Hz, 1H), 7.82 –7.75 (m, 1H), 7.57 (dd, J = 8.1, 1.1 Hz, 1H), 7.49 (td, J = 7.7, 1.1 Hz, 1H), 2.70 (tt, J = 9.0, 5.5 Hz, 1H), 1.81 (dtd, J = 13.5, 9.3, 5.7 Hz, 2H), 1.61 (ddt, J = 13.5, 10.0, 5.8 Hz, 2H), 1.44 – 1.23 (m, 4H), 0.91 (t, J = 7.4 Hz, 6H). 13 CNMR (126 MHz, CDCl3): δ 165.9, 160.2, 146.6, 136.5, 128.5, 128.1, 126.8,117.0, 45.6, 35.1, 20.7, 14.1. Example 24 In this embodiment, a 2-(2-Phenylethyl)-4 H A method for synthesizing 3,1-benzoxazin-4-one (CAS: 404863-84-9), the structure of which is shown in formula (24e): Equation (24e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-(3-phenylpropionyl)indole was evacuated and oxygen was introduced through an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 24e, with a yield of 40%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.20 (dd, J = 7.9, 1.5 Hz, 1H), 7.80(td, J = 7.7, 1.5 Hz, 1H), 7.60 – 7.55 (m, 1H), 7.54 – 7.48 (m, 1H), 7.34 –7.26 (m, 4H), 7.25 – 7.19 (m, 1H), 3.16 (dd, J = 9.4, 6.5 Hz, 2H), 3.01 (dd, J =9.0, 6.8 Hz, 2H). 13 C NMR (126 MHz, CDCl3): δ 162.2, 146.5, 142.3, 140.1,136.6, 128.7, 128.6, 128.5, 128.4, 126.7, 126.6, 117.0, 36.6, 32.1. Example 25 In this embodiment, a method for synthesizing a benzoxazinone derivative is provided, the structure of which is shown in formula (25e): Equation (25e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-[2-(4-chloro-2-methylphenoxy)acetyl]indole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 25e, with a yield of 53%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.22 (dd, J = 7.9, 1.6 Hz, 1H), 7.84(td, J = 7.7, 1.6 Hz, 1H), 7.64 (dd, J = 8.2, 1.2 Hz, 1H), 7.57 (td, J = 7.6, 1.1Hz, 1H), 7.15 (d, J = 2.7 Hz, 1H), 7.09 (dd, J = 8.7, 2.7 Hz, 1H), 6.84 (d, J = 8.6Hz, 1H), 4.99 (s, 2H), 2.31 (s, 3H). 13 C NMR (126 MHz, CDCl3): δ 158.8, 157.6,154.9, 145.8, 136.8, 131.0, 129.7, 129.2, 128.8, 127.3, 126.7, 126.5, 117.4,113.1, 67.4, 16.3. Example 26 In this embodiment, a method for synthesizing a benzoxazinone derivative is provided, the structure of which is shown in formula (26e): Equation (26e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-[2-(4-(4-chlorobenzoyl)phenoxy)-2-methylpropionyl]indole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially by adding 5.0 mL of water and 5.0 mL of ethyl acetate (extraction three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 26e, with a yield of 54%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.21 (dd, J = 7.9, 1.6 Hz, 1H), 7.85(td, J = 7.7, 1.6 Hz, 1H), 7.78 – 7.63 (m, 5H), 7.57 (td, J = 7.6, 1.2 Hz, 1H), 7.49 – 7.39 (m, 2H), 6.99 – 6.90 (m, 2H), 1.87 (s, 6H). 13 C NMR (126 MHz, CDCl3): δ 194.3, 162.9, 159.7, 159.0, 145.7, 138.5, 136.8, 136.4, 132.1,131.2, 131.0, 129.3, 128.8, 128.6, 127.5, 118.3, 117.0, 79.7, 26.1. Example 27 In this embodiment, a method for synthesizing benzalkonium chloride (CAS: 1022-46-4) is provided, the structure of which is shown in formula (27e): Equation (27e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-acetyl-2-phenylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 27e (bentranil), with a separation yield of 88%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.30 (d, J = 7.5 Hz, 2H), 8.26 – 8.20(m, 1H), 7.85 – 7.78 (m, 1H), 7.68 (d, J = 8.1 Hz, 1H), 7.57 (t, J = 7.3 Hz,1H), 7.50 (t, J = 7.5 Hz, 3H). 13 C NMR (126 MHz, CDCl3): δ 159.6, 157.2, 147.1,136.6, 132.7, 130.3, 128.8, 128.7, 128.4, 128.3, 127.3, 117.1. Example 28 In this embodiment, a method for synthesizing 2-ethyl-benzo[D][1,3]oxazin-4-one (CAS: 2916-09-8) is provided, the structure of which is shown in formula (28e): Equation (28e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-acetyl-2-ethylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 28e, with a yield of 76%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.19 (dd, J = 7.9, 1.6 Hz, 1H), 7.79(ddd, J = 8.2, 7.3, 1.6 Hz, 1H), 7.57 (dd, J = 8.1, 1.2 Hz, 1H), 7.50 (ddd, J =8.2, 7.4, 1.2 Hz, 1H), 2.73 (q, J = 7.6 Hz, 2H), 1.37 (t, J = 7.5 Hz, 3H). 13 C NMR (126 MHz, CDCl3): δ 164.0, 160.0, 146.6, 136.6, 128.5, 128.2, 126.7, 117.0,28.3, 10.4. Example 29 In this embodiment, a method for synthesizing 2-(4-fluorophenyl)-4h-3,1-benzoxazin-4-one (CAS: 18600-51-6) is provided, the structure of which is shown in formula (29e): Equation (29e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-acetyl-2-(4-fluorophenyl)indole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 29e, with a yield of 68%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 8.36 – 8.27 (m, 2H), 8.23 ​​(dd, J = 7.9, 1.6 Hz, 1H), 7.82 (ddd, J = 8.6, 7.4, 1.6 Hz, 1H), 7.67 (dd, J = 8.1, 1.1 Hz, 1H), 7.51 (td, J = 7.6, 1.2 Hz, 1H), 7.19 (t, J = 8.7 Hz, 2H). 13 C NMR (126 MHz, CDCl3): δ 165.7 (d, J = 254.2 Hz), 159.5, 156.3, 147.0, 136.7, 130.8, 130.8,128.7, 128.4, 127.2, 126.5, 116.9, 116.2, 116.0. Example 30 In this embodiment, a method for synthesizing N-(2-acetylphenyl)acetamide (CAS: 5234-26-4) is provided, the structure of which is shown in formula (30e): Equation (30e) The synthesis route is as follows: The specific preparation method includes the following steps: A sealed tube containing a magnetic inductor and 0.25 mmol of N-acetyl-3-methylindole was evacuated and oxygen was introduced using an oxygen-filled bulb. Then, under an oxygen atmosphere, acetonitrile (2.0 mL) and p-fluorothiophenol (0.05 mmol) were added sequentially to the system using a syringe. The reaction mixture was placed at 25 °C and stirred for 20 hours under 390 nm blue LED light irradiation. After the reaction was complete, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI, 0.5 mmol) was added to the reaction system, and stirring was continued for 5 minutes. Extraction was then performed sequentially with 5.0 mL of water and 5.0 mL of ethyl acetate (extracted three times). All organic phases were combined and concentrated under reduced pressure. The residue was separated by column chromatography to obtain 30e, with a yield of 90%. NMR characterization data are as follows: MRI: 1 H NMR (500 MHz, CDCl3): δ 11.69 (s, 1H), 8.75 – 8.70 (m, 1H), 7.89 (dd, J = 8.0, 1.6 Hz, 1H), 7.55 (ddd, J = 8.6, 7.3, 1.6 Hz, 1H), 7.18 – 7.08(m, 1H), 2.66 (s, 3H), 2.22 (s, 3H). 13 C NMR (126 MHz, CDCl3): δ 203.0, 169.7,141.1, 135.3, 131.7, 122.4, 120.8, 117.0, 28.7, 25.6. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A benzoxazinone derivative, characterized in that, The structure of the compound is shown in formula (23e), formula (25e), or formula (26e): 。 2. A method for synthesizing a benzoxazinone derivative, characterized in that, The synthetic method uses an N-acylindole compound (Formula I) as the starting substrate and, in an organic solvent system under an oxygen atmosphere, with p-fluorothiophenol as the catalyst, undergoes a photoreaction to obtain an intermediate; then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCl) is introduced for condensation cyclization to obtain a benzoxazinone derivative (Formula II). The synthetic route is selected from any of the following: Route 1: Route 2: Route 3: 。 3. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, R1 is selected from hydrogen, C1-C4 alkyl, and halogen; further, the alkyl is methyl, and the halogen is chlorine or bromine; in some embodiments verified by the present invention, R1 is selected from hydrogen atom, 4-methyl, 5-methyl, 5-chlorine, or 5-bromine.

4. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, In Route 1, R2 is selected from alkyl, aryl, heteroaryl, or alkoxy groups; further, R2 is selected from C1-C6 groups with substituted or unsubstituted functional groups. 20 Alkyl groups, C6-C with substituted or unsubstituted functional groups 20 C3-C of aryl, substituted or unsubstituted functional groups 20 C1-C of heteroaryl, substituted or unsubstituted functional groups 20 Any of the alkoxy groups includes both straight-chain and branched substitutions, and the functional group is selected from one or more of alkyl, halogen, alkoxy, acyloxy, aryl, aryloxy, and sulfonamide groups. In some embodiments verified by the present invention, the alkyl group is selected from methyl, tert-butyl, benzyl, phenyl, p-methylphenyl, p-tert-butylphenyl, m-methylphenyl, m-chlorophenyl, o-methylphenyl, o-iodophenyl, o-bromophenyl, 2-naphthyl, 2-thienyl, p-N,N-dipropylaminosulfonylphenyl, o-methoxyphenyl, hexadecyloxy, n-heptadecyl, p-acetoxyphenyl, 2-propylpentyl, phenethyl, (4-chloro-2-methylphenoxy)-methyl, 2-(4-(4-chlorobenzoyl)phenoxy)-2-propyl.

5. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, In Route 2, R3 is selected from ethyl, unsubstituted aryl, or halogen-substituted aryl; in some embodiments verified by the present invention, R3 is selected from ethyl, phenyl, or p-fluorophenyl (4-fluorophenyl).

6. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, In Route 3, R4 is a C1-C4 alkyl group, and in some embodiments verified by this invention, R4 is a methyl group.

7. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, The molar ratio of the N-acylindole compound, oxygen, p-fluorothiophenol and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide is 0.8~1.2:0.1~0.3:0.8~1.2:0.8~2.

2.

8. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, The organic solvent is acetonitrile.

9. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, The photoreaction was performed at room temperature, using blue light with a wavelength of 380-400 nm and an illumination time of 15-25 hours.

10. The method for synthesizing the benzoxazinone derivative as described in claim 2, characterized in that, After condensation and cyclization, the reaction system should be extracted and separated by column chromatography to obtain the corresponding benzoxazinone derivative. The extraction reagent is water and ethyl acetate in a volume ratio of 0.8~1.2:0.8~1.

2. After extraction, the organic phase is retained and concentrated. The column chromatography separation is performed using silica gel column chromatography to separate the crude product. The elution solvent is a mixture of petroleum ether and ethyl acetate.

Images