Benzo[b]selenophene-based STING modulators, their preparation and use

Abstract

The present invention belongs to the technical field of chemical medicine, and particularly relates to a benzo[b]selenophene-based STING regulator, its preparation method and use, the compound structure is as shown in Formula I. The derivatives, salts, stereoisomers, prodrug molecules and pharmaceutical compositions thereof of the present invention can be used as immunoregulators to effectively activate intrinsic immunoregulatory pathways and kill tumor cells. [Formula 1] TIFF2024525976000025.tif37122

Description

[Technical Field]

[0001] The present invention relates to the field of chemical medicine, and in particular to benzo[b]selenophene derivatives, their pharmaceutically acceptable salts, and their use in medicine. [Background technology]

[0002] Cancer immunotherapy aims to treat cancer by activating the body's own immune system to attack and eliminate tumor cells. The emergence of immunotherapy has provided excellent therapeutic effects and innovative research concepts for tumor cure, and was recognized as the most important scientific breakthrough in 2013 by the journal Science (Science. 2015, 348, 56-61). Among these, immune checkpoint blockade therapy and chimeric antigen receptor T cell therapy offer powerful treatment options for cancer patients and have attracted widespread attention (Drug Discov Today. 2020, 25, 230-237).

[0003] In recent years, the cGAS-STING pathway has been considered an important potential target for tumor immunotherapy. First, the cGAS-STING pathway belongs to the pattern recognition receptors (PRs) and is an important component of the body's innate immune regulation (Nature. 2016, 535, 65-74). It captures and recognizes abnormal DNA in the cytoplasm, activating downstream signaling pathways and playing a role in immune responses, such as regulating the expression of type I interferons. This signaling pathway is initiated by the activation of cyclic GMP-AMP synthase. cGAS is one of the intracellular DNA receptors, and upon binding to cytoplasmic DNA, it induces allostery of the cGAS protein, catalyzing the synthesis of cyclic dinucleotide 2'-3' cGAMP from ATP and GTP (Nat. Immunol. 2016, 17, 1142-1149). As a second messenger, cGAMP binds to the endoplasmic reticulum receptor STING (stimulator of interferon genes) and activates STING. The STING receptor protein then undergoes a series of allostery and translocation events, ultimately recruiting TBK1 kinase to the Golgi apparatus, where it phosphorylates the downstream cytokines IRF3 and NF-κB (Curr. Opin. Cell Biol. 2019, 59, 1-7). The phosphorylated cytokines enter the nucleus and regulate downstream type I interferon gene expression and type I interferon secretion, further modulating immune responses (Nature. 2019, 567, 394-398).

[0004] The cGAS-STING pathway, a key regulatory pathway for the body's immune response, is closely linked to many diseases. Initial studies have identified excessive activation of the cGAS-STING pathway as one of the triggers of various chronic inflammatory and autoimmune diseases (Cell Mol. Immunol. 2019, 16, 236-241). On the other hand, based on the potent regulatory ability of cGAS-STING on immune responses, activating this pathway is considered an important target in tumor immunotherapy (J. Hematol. Oncol. 2019, 12, 35). In the cGAS-STING pathway, the transmembrane receptor STING is the most important node for regulating this pathway. Therefore, developing a new generation of drugs that can activate STING receptors will play an important role in improving the therapeutic efficacy of existing tumor immunotherapies. In preclinical mouse tumor models, STING agonists have demonstrated efficient antitumor activity, completely inhibiting tumor growth and even eliminating tumors (Nature. 2018, 564, 439-443; Science. 2020, 369, eaba6098; Science. 2020, 369, 993-999).

[0005] To date, STING agonists have been developed by several pharmaceutical companies, including Novartis' ADU-S100 and Merck's MK-1454, which have entered clinical trials one after another. Clinical development of STING agonists is currently in its early stages, and the development of a new generation of highly efficient, low-toxicity STING modulators with high efficacy and role, as well as excellent drug absorption activity, is highly desirable. Summary of the Invention

[0006] The present invention aims to discover candidate antitumor compounds with novel structures, high activity, minimal side effects, and favorable drug metabolism properties, which, when used alone or in combination with other antitumor drugs, can enhance the therapeutic efficacy and reduce the dose and toxicity of existing antitumor drugs. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention discloses compounds of general formula (I), stereoisomers or pharmaceutically acceptable salts thereof: [ka] During the ceremony, R 1 represents a hydrogen atom, halogen, cyano group, nitro group, OR 6 , N(R 6 )2, C1-C6 alkyl group, C1-C6 haloalkyl group, OR 6 C1-C6 alkyl group or N(R 6 ) C1-C6 alkyl groups substituted with 2; R 2 represents a hydrogen atom, halogen, cyano group, nitro group, OR 6 , S.R. 6 , N(R 6 )2, COOR 6 , C(O)N(R 6 )2, C1-C6 alkyl group, C1-C6 haloalkyl group, OR 6 C1-C6 alkyl group substituted with N(R 6 ) selected from a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 haloalkenyl group, a C2-C6 alkynyl group, a C2-C6 haloalkynyl group, or a C3-C6 cycloalkyl group substituted with 2; R 3 represents a hydrogen atom, halogen, cyano group, nitro group, OR 6 , S.R. 6 , N(R 6 )2, COOR 6 , C(O)N(R 6 )2, C1-C6 alkyl group, C1-C6 haloalkyl group, OR 6 C1-C6 alkyl group substituted with N(R 6 ) selected from a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 haloalkenyl group, a C2-C6 alkynyl group, a C2-C6 haloalkynyl group, or a C3-C6 cycloalkyl group substituted with 2; Or R 2 and R 3forms a 5- or 6-membered heterocyclic ring together with the atom to which it is connected, containing 1 to 2 ring members selected from O, S, or N; R 4 represents a hydrogen atom, halogen, cyano group, nitro group, OR 6 , N(R 6 )2, C1-C6 alkyl group, C1-C6 haloalkyl group, OR 6 C1-C6 alkyl group or N(R 6 ) C1-C6 alkyl groups substituted with 2; R 5 is selected from a hydrogen atom, a halogen, a cyano group, a C1-C6 alkyl group, a C1-C6 haloalkyl group, and a C3-C6 cycloalkyl group, R on the same atom 6 are the same or different, and R on different atoms 6 are the same or different, and each R 6 are independently a hydrogen atom, a C1-C6 alkyl group, a C1-C6 haloalkyl group, a C3-C6 cycloalkyl group, a C3-C8 heterocyclic group, or a C5-C 10 aryl groups, X 1 is C(O), X 2 is (C(R 7 )2) (1~3) and R on the same atom 7 are the same or different, and R on different atoms 7 are the same or different, and each R 7 are independently hydrogen atoms, halogens, CN, OR 6 , N(R 6 )2, C1-C6 alkyl group, C1-C6 haloalkyl group, OR 6 and C1-C6 alkyl or C3-C6 cycloalkyl groups substituted with Or, two R on different carbon atoms 7 can form a 3- to 6-membered ring with the atoms to which it is attached, Or, two R on a single carbon atom 7 can form a 3- to 6-membered ring with the atoms to which it is attached, X 3COOR 6 , C(O)N(R 6 )2, C(O)NHOH, SO2R 6 , S(O)NR 6 or C(CF3)2OR 6 Selected from.

[0008] In one preferred embodiment of the present invention, R 1 is selected from a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 haloalkyl group, and is preferably a hydrogen atom or a fluorine atom; R 2 is selected from a hydrogen atom, a halogen, a C1-C3 alkyl group, a C1-C3 haloalkyl group, an O-C1-C3 alkyl group, an O-C1-C3 haloalkyl group, or —OH, and is preferably a hydrogen atom, a fluorine atom, a chlorine atom, CH3, CH2CH3, OCH3, OCH2CH3, OCH(CH3)2, or OCHF2, R 3 is selected from a hydrogen atom, a halogen, a C1-C3 alkyl group, a C1-C3 haloalkyl group, an O-C1-C3 alkyl group, an O-C1-C3 haloalkyl group, or -OH, and is preferably a hydrogen atom, -OH, a fluorine atom, a chlorine atom, CH3, CH2CH3, OCH3, OCH2CH3, OCH(CH3)2, or OCHF2, R 4 is selected from a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 haloalkyl group, and is preferably a hydrogen atom or a fluorine atom; R 5 is selected from a hydrogen atom, a halogen, a C1-C3 alkyl group, or a C1-C3 haloalkyl group, and is preferably a hydrogen atom; X 1 is C(O), X 2 is CH2CHR 7 and X 3 COOR 6 , C(O)N(R 6 )2, C(O)NHOH, SO2R 6 , S(O)NR 6 or C(CF3)2OR 6Preferably, COOH, COOCH3, COOCH2CH3, C(O)NHOH; Each R 6 are independently a hydrogen atom, a C1-C3 alkyl group, a C1-C3 haloalkyl group, a C3-C6 cycloalkyl group, a C3-C8 heterocyclic group, or a C5-C 10 aryl groups, Each R 7 are independently selected from a hydrogen atom, a fluorine atom, a C1-C4 alkyl group, a C1-C4 haloalkyl group, a C3-C6 cycloalkyl group, or a C1-C4 alkyl group substituted with OC1-C3, and are preferably a hydrogen atom, CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CHOCH3, or a cyclopropyl group.

[0009] In a second preferred embodiment of the present invention, R 1 is selected from a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 haloalkyl group, and is preferably a hydrogen atom or a fluorine atom; R 2 is selected from a hydrogen atom, a halogen, a C1-C3 alkyl group, a C1-C3 haloalkyl group, an OC1-C3 alkyl group, an OC1-C3 haloalkyl group, or OH, and is preferably a fluorine atom, a chlorine atom, CH3, CH2CH3, OCH3, OCH2CH3, OCH(CH3)2, or OCHF2; R 3 is selected from a hydrogen atom, a halogen, a C1-C3 alkyl group, a C1-C3 haloalkyl group, an OC1-C3 alkyl group, an OC1-C3 haloalkyl group, or OH, and is preferably a fluorine atom, a chlorine atom, CH3, CH2CH3, OCH3, OCH2CH3, OCH(CH3)2, or OCHF2; R 4 is selected from a hydrogen atom, a fluorine atom, a C1-C3 alkyl group, or a C1-C3 haloalkyl group, and is preferably a hydrogen atom or a fluorine atom; R 5 is selected from a hydrogen atom, a halogen, a C1-C3 alkyl group, or a C1-C3 haloalkyl group, and is preferably a hydrogen atom; X 1is C(O), X 2 is CHR 7 CHR 7 and X 3 COOR 6 , C(O)N(R 6 )2, C(O)NHOH, SO2R 6 , S(O)NR 6 or C(CF3)2OR 6 Preferably, COOH, COOCH3, COOCH2CH3, C(O)NHOH; Each R 6 are independently a hydrogen atom, a C1-C3 alkyl group, a C1-C3 haloalkyl group, a C3-C6 cycloalkyl group, a C3-C8 heterocyclic group, or a C5-C 10 aryl groups, Each R 7 are independently selected from a hydrogen atom, a fluorine atom, a C1-C4 alkyl group, a C1-C4 haloalkyl group, a C3-C6 cycloalkyl group, or a C1-C4 alkyl group substituted with O-C1-C3, or two R 7 forms a 3- to 6-membered ring with the atoms to which it is attached.

[0010] In some specific examples, R 1 , R 4 and R 5 are all hydrogen atoms.

[0011] In some specific examples, the present invention further provides compounds according to formula I-1. [ka] In the formula, X 2 is CHR 7 CHR 7 and R 7 are the same or different, and each R 7 are independently a hydrogen atom, a halogen, CN, a C1-C6 alkyl group, a C1-C6 haloalkyl group, OR 6or a C1-C6 alkyl group substituted with two R on different carbon atoms, or a C3-C6 cycloalkyl group substituted with 7 can form a 3- to 6-membered ring with the atoms to which it is attached, and R 6 are independently a hydrogen atom, a C1-C3 alkyl group, a C1-C3 haloalkyl group, a C3-C6 cycloalkyl group, a C3-C8 heterocyclic group, or a C5-C 10 It is selected from aryl groups.

[0012] The pharmaceutically acceptable salt of the compound of general formula (I) according to the present invention refers to a salt prepared from the compound of general formula (I) and a pharmaceutically acceptable non-toxic alkali, including inorganic alkali or organic alkali. Salts prepared from inorganic alkali include aluminum salt, ammonium salt, calcium salt, lithium salt, magnesium salt, potassium salt, sodium salt, zinc salt, etc. Particularly preferred are ammonium salt, calcium salt, magnesium salt, potassium salt and sodium salt. In salts derived from pharmaceutically acceptable non-toxic organic alkalis, the alkalis include salts of primary, secondary, and tertiary amines, including naturally occurring substituted amines, cyclic amines, and alkaline ion exchange resins such as betaine, caffeine, choline, N-ethylpiperidine, N,N'-dibenzylethylenediamine, diethylamine, 2-dimethylaminoethanol, arginine, ethanolamine, ethylenediamine, N-ethylmorpholine, glucosamine, methylglucamine, 2-diethylaminoethanol, glucosamine, histidine, aminoethanol, hydroxocobalamin, lysine, morpholine, piperazine, piperidine, hydrazones, polyamine resins, triethylamine, trimethylamine, tripropylamine, isopropylamine, and tromethamine.

[0013] The present invention further provides any of the following specific compounds or pharmaceutically acceptable salts thereof: [ka]

[0014] Another object of the present invention is to provide a method for preparing the compound represented by general formula (I), which comprises the following steps:

[0015] When the compound is a compound represented by general formula (Ia), the synthetic route is as follows. [ka] In the formula, R 2 , R 3 and R 7 is as mentioned above, and R 8 may be CH3, CH2CH3, or C(CH3)3, and R 9 may be CH3, CH2CH3, and X may be Cl, Br, or I.

[0016] In some more specific examples, R 2 and R 3 are each independently selected from a fluorine atom, a chlorine atom, CH3, CH2CH3, OCH3, OCH2CH3, and OCH(CH3)2, and R 3 may be CH3, CH2CH3, or C(CH3)3, and R 7 may be a hydrogen atom, CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2OCH3, and a cyclopropyl group; R 5 may be CH3, CH2CH3, and X may be Cl, Br, or I.

[0017] In some more specific examples, in the process of producing compound (IV) from compound (II), the reactant may be dimethyl diselenide (III), the reaction reagents may be DTT, mercaptoethanol, potassium carbonate and DBU, and the solvent may be tetrahydrofuran and DMF.

[0018] In some more specific examples, in the process of producing compound (VI) from compound (IV), the reactant may be 2-ethyl bromoacetate (V) and the reaction reagent may be DMF.

[0019] In some more specific examples, in the process of producing compound (VII) from compound (VI), the reaction reagents may be potassium carbonate, sodium carbonate and sodium hydroxide, and the reaction solvent may be DMF and acetonitrile.

[0020] In some more specific examples, in the process of producing compound (VIII) from compound (VII), the reaction reagent may be potassium carbonate, sodium hydroxide, or lithium hydroxide, and the reaction solvent may be water, methanol, or tetrahydrofuran.

[0021] In some more specific examples, in the process of preparing compound (X) from compound (VIII), the reactant is monopotassium malonate (IX), the reaction reagent may be CDI, MgCl, and the reaction solvent may be tetrahydrofuran and DMF.

[0022] In some more specific examples, in the process of producing compound (XII) from compound (X), the reactant may be haloacid ester (XI), the reaction reagent may be potassium carbonate, sodium ethoxide and sodium hydride, and the reaction solvent may be tetrahydrofuran and DMF.

[0023] In some more specific examples, in the process of preparing compound (Ia) of the general formula from compound (XII), the reaction reagent may be potassium carbonate, sodium hydroxide, or lithium hydroxide, and the reaction solvent may be hydrochloric acid, acetic acid, water, or tetrahydrofuran.

[0024] When the compound is a compound represented by general formula (Ib), the synthetic route is as follows. [ka] In the formula, R 2 and R 3 is as described above, and n represents 1, 2, 3, or 4. In a more specific example, R 2 and R 3are each independently selected from a fluorine atom, a chlorine atom, CH3, CH2CH3, OCH3, OCH2CH3, and OCH(CH3)2, and n represents 1, 2, 3, or 4.

[0025] In some more specific examples, in the process of producing compound XIII from compound (VIII), the reaction reagent is copper powder and the reaction solvent is quinoline.

[0026] In some more specific examples, in the process of preparing compound (Ib) of the general formula from compound XIII, the reactant is succinic anhydride (XIV) having different substitutions, the reaction reagents are aluminum trichloride, zinc chloride and titanium tetrachloride, and the reaction solvent is dichloromethane.

[0027] The present invention provides a pharmaceutical composition comprising a pharmaceutically effective amount of an active ingredient and a pharmaceutically acceptable excipient, wherein the active ingredient comprises one or more of the compounds of general formula (I) or pharmaceutically acceptable salts thereof, wherein the excipient comprises a pharmaceutically acceptable carrier, diluent and / or excipient.

[0028] The pharmaceutical composition can be prepared in various types of unit dosage forms depending on the therapeutic purpose, such as tablets, pills, powders, liquids, suspensions, emulsions, granules, capsules, and injections (solutions or suspensions), and preferably tablets, capsules, liquids, suspensions, and injections (solutions or suspensions).

[0029] The compounds of the present invention can be administered clinically by oral administration, injection, or the like.

[0030] The present invention further provides use of a compound represented by general formula (I) or a pharmaceutically acceptable salt or pharmaceutical composition thereof in the manufacture of a drug that activates the cGAS-STING pathway.

[0031] The present invention further provides a use of a compound represented by general formula (I) or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable pharmaceutical composition thereof in the manufacture of a drug, wherein the drug is for treating a disease associated with STING pathway activity.

[0032] The present invention further provides the use of a compound represented by general formula (I) or a pharmaceutically acceptable salt thereof or a pharmaceutically acceptable pharmaceutical composition thereof in the manufacture of a medicament for treating autoimmune diseases, infectious diseases, cancer and precancerous syndromes, wherein cancer includes malignant melanoma, colon cancer, breast cancer, lung cancer and squamous cell carcinoma.

[0033] The present invention further provides use of a compound represented by general formula (I) or a pharmaceutically acceptable salt thereof or a pharmaceutically acceptable pharmaceutical composition thereof in the manufacture of an immune adjuvant.

[0034] Unless otherwise stated, the following terms used in the specification and claims have the meanings set forth below.

[0035] The term "alkyl group" refers to a monovalent linear or branched saturated aliphatic hydrocarbon group having a number of carbon atoms within the specified range. The alkyl group may be substituted or unsubstituted. If the alkyl group is substituted, the group preferably has one or more substituents, more preferably one to three substituents, and most preferably one or two substituents.

[0036] The term "alkenyl group" refers to a non-aromatic hydrocarbon group, straight, branched, or cyclic, whose backbone contains a specified number of carbon atoms and at least one carbon-carbon double bond. Alkenyl groups include vinyl, propenyl, butenyl, 2-methylbutenyl, cyclohexenyl, and the like. The straight, branched, or cyclic portion of the alkenyl group may contain a double bond, and may be substituted if a substituted alkenyl group is specified.

[0037] The term "alkynyl group" refers to a non-aromatic hydrocarbon group, straight, branched, or cyclic, whose backbone contains a specified number of carbon atoms and at least one carbon-carbon triple bond. Alkynyl groups include ethynyl, propynyl, butynyl, 3-methylbutynyl, and the like. The straight, branched, or cyclic portion of an alkynyl group may contain a triple bond, and may be substituted if a substituted alkynyl group is specified.

[0038] The term "halogen" denotes fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine.

[0039] The term "haloalkyl group" refers to an alkyl group as defined above in which one or more hydrogen atoms have been replaced with a halogen.

[0040] The term "haloalkenyl" refers to an alkenyl group as defined above in which one or more hydrogen atoms have been replaced with a halogen.

[0041] The term "haloalkynyl" refers to an alkynyl group as defined above in which one or more hydrogen atoms have been replaced with a halogen.

[0042] The term "cycloalkyl group" refers to an all-carbon monocyclic or fused-ring ("fused" rings means that each ring in the system shares an adjacent pair of carbon atoms with each other ring in the system) group, where one or more rings do not have a fully connected pi-electron system; examples of cycloalkyl groups include, but are not limited to, cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, adamantane, cyclohexadiene, cycloheptane, and cycloheptatriene. Cycloalkyl groups can be substituted or unsubstituted.

[0043] The term "fused ring" refers to a cyclic group formed from substituents on different atoms in a straight or branched chain alkane, or to a cyclic group formed from substituents on different atoms in another ring.

[0044] The term "heterocyclic group" refers to a saturated cyclic group of 3 to 8 ring atoms, where one or two ring atoms are N, O, or S(O). m (wherein m is an integer of 0 to 2), and the remaining ring atoms are C, of which one or two C atoms may optionally be substituted with a carbonyl group.

[0045] The term "aryl group" refers to an all-carbon monocyclic or fused polycyclic group of 5 to 10 carbon atoms and having a completely conjugated π-electron system. Non-limiting examples of aryl groups include phenyl, naphthyl, and anthryl groups. Aryl groups can be substituted or unsubstituted.

[0046] The present invention includes salts, solvates and solvated salts of all possible isomers, as well as racemates, enantiomers, diastereoisomers, tautomers and mixtures thereof. [Example]

[0047] To further illustrate the present invention, a series of examples are presented below. However, these examples are merely illustrative and are intended to illustrate the present invention and should not be construed as limitations on the present invention.

[0048] The materials and equipment used in the specific embodiments of the present invention are all known products and can be purchased commercially. Abbreviation DTT DL-Dithiothreitol DBU 1,8-Diazabicyclo[5.4.0]undec-7-ene 1 HNMR Proton Nuclear Magnetic Resonance Spectroscopy 13 CNMR 13C nuclear magnetic resonance spectrum HRMS High resolution mass spectrometer DMSO Dimethyl sulfoxide CDCl3 deuterated chloroform TLC Thin-layer chromatography DMF N,N-dimethylformamide CDI N,N-Carbonyldiimidazole

[0049] Example 1 [ka]

[0050] Process 1 Preparation of 4,5-dimethoxy-2-(methylseleno)benzaldehyde (IV-1) Add 3.14 g of DTT (20.4 mmol), 2.56 g of dimethyl diselenide (III, 13.6 mmol), and 50 mL of DMF to a 250 mL one-neck flask and stir at room temperature under nitrogen gas protection for 1 h. Then, add 5.0 g (20.4 mmol) of 2-bromo-4,5-dimethoxybenzaldehyde (II-1) and 7.76 g (51 mmol) of DBU to the reaction flask and stir overnight at room temperature under nitrogen gas protection. Monitor the reaction by TLC and stop the reaction when reactant II-1 is completely reacted. Pour the reaction solution into 200 mL of ice water to precipitate a solid. After suction filtration, wash the cake with water, and dry, obtain 4.46 g of a pale yellow solid, a yield of 84%. 1 HNMR(300MHz,CDCl3):δ=10.19(s,1H),7.35(s,1H),7.00(s,1H),3.99(s,3H),3.94(s,3H),2.32(s,3H)ppm.HRMS(ESI + ):C 10 H 13 O3Se(M+H) + ,261.0024;found,261.0021.

[0051] Process 2 Preparation of ethyl 2-((2-formyl-4,5-dimethoxyphenyl)seleno)acetate (VI-1) 4.0 g of compound IV-1 (15.4 mmol) and 8.5 mL of ethyl bromoacetate (77 mmol) were added to a 100 mL one-neck flask and stirred at 170 °C for 4 h. After monitoring the complete reaction of compound IV-1 by TLC, the reaction was stopped. After cooling to room temperature, the reaction mixture was diluted with 30 mL of water and extracted twice with 50 mL of ethyl acetate. The organic layers were combined, washed with 50 mL of water and 30 mL of saturated brine, dried over anhydrous sodium sulfate, and filtered under suction. The solvent was removed from the filtrate by distillation under reduced pressure to obtain a brown oil, which was directly used in the next step without further purification. HRMS (ESI) + ):C 13 H 17 O5Se(M+H) + ,333.0236;found,333.0233.

[0052] Process 3 Preparation of ethyl 5,6-dimethoxybenzo[b]selenophene-2-carboxylate (VII-1) Compound VI-1 obtained in the previous step was placed in a 100 mL single-neck flask, and 7.6 g of potassium carbonate (55 mmol) and 25 mL of acetonitrile were added. The reaction was refluxed for 6 hours. After TLC confirmed that the raw materials had completely reacted, heating was stopped. The reaction solution was filtered under suction, the solvent was removed under reduced pressure, 50 mL of water was added, and the mixture was extracted twice with 40 mL of ethyl acetate. The organic layers were combined, washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, filtered under suction, and concentrated. The crude product was purified by silica gel column chromatography to obtain 3.2 g of an ochre solid, with a combined yield of 46% for the two steps. 1 HNMR(300MHz,CDCl3):δ=8.17(s,1H),7.31(s,1H),7.28(s,1H),4.40(q,J=7.1Hz,.2H),3.97(s,3H),3.94(s,3H),1.41(t,J=7.1Hz,.3H)ppm.HRMS(ESI + ):calcd for C 13 H 14 O4Se(M+H) + 315.0130;found,315.0124.

[0053] Process 4 Preparation of 5,6-dimethoxybenzo[b]selenophene-2-carboxylic acid (VIII-1) 3.2 g of compound VII-1, 35 mL of tetrahydrofuran, and 35 mL of methanol were added to a 250 mL reaction flask. A total of 15 mL of 2N aqueous sodium hydroxide was added at room temperature, and the mixture was stirred at 60 °C for 3 h. After TLC showed the reaction was complete, the reaction mixture was concentrated and the pH was adjusted to 3-4 with 1N hydrochloric acid to precipitate a solid. The mixture was filtered under suction, washed with water, and dried to obtain 2.9 g of a pale yellow solid, a yield of 98%. 1 HNMR(300MHz,CDCl3):δ=8.28(s,1H),7.34(s,1H),7.31(s,1H),3.98(s,3H),3.95(s,3H)ppm.HRMS(ESI - ):C 11 H9O4Se(MH) - ,284.9672;found,284.9674.

[0054] Example 2 [ka] Preparation of ethyl 3-(5,6-dimethoxybenzo[b]selenophen-2-yl)-3-oxopropionate (X-1) 2.9 g of compound VIII-1 (10.1 mmol), 5.1 g of CDI (31.6 mmol), and 50 mL of anhydrous tetrahydrofuran were added to a 100 mL reaction flask and stirred at room temperature for 1 h. 5.4 g of potassium ethyl malonate (31.6 mmol) and 3.0 g of magnesium chloride (31.6 mmol) were added to the reaction mixture and stirred at room temperature for 4 h. After the reaction was confirmed to be complete by TLC, 50 mL of water was added to dilute the reaction mixture and extracted twice with 40 mL of ethyl acetate. The combined organic layers were washed with water and saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain 3.0 g of a yellow solid in 84% yield. 1HNMR (300MHz, CDCl3): δ=8.09(s,1H),7.33(s,1H),7.30(s,1H),4.26(q,J=7.1Hz,2H),3.98(s,5H),3.94(s,3H),1.30(t,J=7.1Hz,3H)ppm. HRMS(ESI + ):C 15 H 17 O5Se(M+H) + ,357.0236;found,357.0231.

[0055] Example 3 [ka]

[0056] Process 1 Preparation of diethyl 2-(5,6-dimethoxybenzo[b]selenophene-2-formyl)succinate (XII-1) Add 0.17 g of compound X-1 (0.5 mmol), 0.14 g of potassium carbonate (1 mmol), and 5 mL of DMF to a 100 mL reaction flask and stir at room temperature for 30 min. Add 0.13 g of 2-ethylbromoacetate (0.75 mmol) and 8 mg of potassium iodide (0.05 mmol) to the reaction mixture and stir at room temperature for 4 h. After monitoring the reaction completion by TLC, add 20 mL of water to the reaction mixture and extract twice with 20 mL of ethyl acetate. The combined organic layer was washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to give a yellow oil, which was directly used in the next step without further purification. HRMS (ESI) + ):C 19 H 23 O7Se(M+H) + ,443.0604;found,443.0600.

[0057] Process 2 Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-4-oxobutyric acid (I-1) Compound XII-1 obtained in the previous step, 2 mL of concentrated hydrochloric acid, and 2 mL of acetic acid were added to a 100 mL reaction flask and stirred at 100 °C for 3 h. After monitoring the complete reaction of compound XII-1 by TLC, the reaction mixture was cooled to room temperature, diluted with 20 mL of water, and extracted twice with 20 mL of ethyl acetate. The combined organic layers were washed with water and saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain 45 mg of a white solid, for a combined yield of 26% for the two steps. 1 HNMR (300MHz, DMSO-d6): δ=8.42(s,1H),7.70(s,1H),7.53(s,1H),3.84(s,3H),3.82(s,3H),3.24(sbr,2H),2.57(sbr,2H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.99,174.14,150.77,148.81,145.06,137.15,135.46,134.61,109.36,108.37,56.24,56.01,32.98,28.49ppm.HRMS(ESI - ):C 14 H 13 O5Se(MH) - ,340.9934;found,340.9933.

[0058] Example 4 Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-2) Compound I-2 was obtained by the same synthesis method as described in Example 3, except that ethyl 2-bromopropionate was used instead of 2-ethyl bromoacetate. 1 HNMR(300MHz,DMSO-d6):δ=12.19(s,1H),8.43(s,1H),7.70(s,1H),7.51(s,1H),3.85(s,3H),3 .82(s,3H),3.43-3.37(m,1H),3.11-3.03(m,1H),2,92-2.85(m,1H),1.19(d,J=7.1Hz,3H)ppm. 13CNMR(75MHz,CDCl3):δ=192.78,181.10,150.67,148.70,145.30,138.00,135 .02,133.08,108.21,107.02,56.17,56.03,41.25,35.18,17.10ppm.HRMS(ESI - ):C 15 H 15 O5Se(MH) - ,355.0090;found,355.0091.

[0059] Example 5 [ka]

[0060] Process 1 Preparation of diethyl (3R)-2-(5,6-dimethoxybenzo[b]selenophene-2-formyl)-3-methylsuccinate (XII-2) Add 0.17 g of compound X-1 (0.5 mmol), 0.14 g of potassium carbonate (1 mmol), and 5 mL of DMF to a 100 mL reaction flask and stir at room temperature for 30 min. Add 0.14 g of ethyl S-2-chloropropionate (1 mmol) to the reaction mixture and stir at 55 °C overnight. Monitor the reaction by TLC. Add 20 mL of water to the reaction mixture and extract twice with 20 mL of ethyl acetate. The combined organic layers were washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to give a yellow oil, which was directly used in the next step without further purification. HRMS (ESI) + ):C 20 H 25 O7Se(M+H) + ,457.0760;found,457.0758.

[0061] Process 2 Preparation of R-4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-3) Compound XII-2 obtained in the previous step, 2 mL of concentrated hydrochloric acid, and 2 mL of acetic acid were added to a 100 mL reaction flask and stirred at 100 °C for 3 h. After monitoring the complete reaction of compound XII-2 by TLC, the reaction mixture was cooled to room temperature, diluted with 20 mL of water, and extracted twice with 20 mL of ethyl acetate. The combined organic layers were washed with water and saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to obtain the crude product. The crude product was purified by chiral preparative separation to yield 15 mg of a pale yellow solid with a 95% ee, representing a combined yield of 9% for the two steps. 1 HNMR(300MHz,DMSO-d6):δ=12.20(s,1H),8.42(s,1H),7.69(s,1H),7.51(s,1H),3.85(s,3H),3 .82(s,3H),3.43-3.37(m,1H),3.08-3.01(m,1H),2.91-2.84(m,1H),1.18(d,J=7.1Hz,3H)ppm. 13 CNMR(75MHz, CDCl3):δ=191.59,180.78,151.88,147.46,145.55,138.37,134.62,132.20,108.17,107.76,56.19,55.96,41.19,34.84 17.06ppm.HRMS(ESI - ):C 15 H 15 O5Se(MH) - ,355.0090;found,355.0088.

[0062] Example 6 Preparation of S-4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-4) Referring to the preparation method described in Example 5, compound X-1 was used as the raw material, and R-2-ethyl chloropropionate was used instead of S-ethyl 2-chloropropionate. The same synthesis method was used to obtain 19 mg of compound I-4, with an ee of 95%. The total yield of the two steps was 11%. 1HNMR(300MHz,DMSO-d6):δ=12.12(s,1H),8.42(s,1H),7.70(s,1H),7.51(s,1H),3.85(s,3H),3 .82(s,3H),3.43-3.37(m,1H),3.09-3.02(m,1H),2.91-2.85(m,1H),1.19(t,J=6.9Hz,3H)ppm. 13 CNMR(75MHz,CDCl3):δ=192.30,181.22,150.92,147.69,145.17,137.61,135 .08,133.27,109.03,107.21,56.25,56.08,42.67,34.44,17.25ppm.HRMS(ESI - ):C 15 H 15 O5Se(MH) - ,355.0090;found,355.0089.

[0063] Example 7 Preparation of 4-(5-methoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-5) With reference to the preparation method described in Examples 1-3, the target compound I-5 is obtained by using 2-bromo-5-methoxybenzaldehyde instead of 2-bromo-4,5-dimethoxybenzaldehyde as the starting material and 2-bromoethyl propionate instead of 2-ethyl bromoacetate as the reactant, and by the same synthesis method. 1 HNMR(300MHz,DMSO-d6):δ=12.22(s,1H),8.51(s,1H),8.00(d,J=8.8Hz,1H),7.56(d,J=2.6Hz,1H),7.13(dd,J1=8. 8Hz,J2=2.6Hz,1H),3.83(s,3H),3.48-3.39(m,1H),3.15-3.08(m,1H),2.96-2.84(m,1H),1.20(d,J=7.2Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=194.52,175.23,150.69,146.38,144.21,138.17,135.45,133.80,109.24,107.26,56.07,42.31,37.16,17.47ppm.HRMS(ESI- ):C 14 H 13 O4Se(MH) - ,324.9985;found,324.9981.

[0064] Example 8 Preparation of 4-(6-methoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-6) Referring to the preparation method described in Examples 1-3, the target compound I-6 is obtained by using 2-bromo-4-methoxybenzaldehyde instead of 2-bromo-4,5-dimethoxybenzaldehyde as the starting material and 2-bromoethyl propionate instead of 2-ethyl bromoacetate as the reactant, using the same synthesis method. 1 HNMR(300MHz,DMSO-d6):δ=12.19(s,1H),8.50(s,1H),7.92(d,J=8.8Hz,1H),7.72(s,1H),7.09(dd,J1=8.8Hz, J2=2.3Hz,1H),3.84(s,3H),3.45-3.33(m,1H),3.12-3.05(m,1H),2.92-2.85(m,1H),1.19(d,J=7.2Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.37,173.79,150.51,146.26,143.35,138.01,135.14,133.06,110.20,106.93,56.15,41.29,35.05,17.20ppm.HRMS(ESI - ):C 14 H 13 O4Se(MH) - ,324.9985;found,324.9984.

[0065] Example 9 Preparation of 4-(5-hydroxy-6-methoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-7) Referring to the preparation method described in Examples 1-3, the target compound I-7 is obtained by using 2-bromo-5-hydroxy-4-methoxybenzaldehyde instead of 2-bromo-4,5-dimethoxybenzaldehyde as the starting material and 2-bromoethyl propionate instead of 2-ethyl bromoacetate as the reactant, and by the same synthesis method. 1 HNMR(300MHz,DMSO-d6):δ=12.17(s,1H),9.34(s,1H),8.38(s,1H),7.63(s,1H),7.35(s,1H),3 .86(s,3H),3.42-3.36(m,1H),3.10-3.02(m,1H),2.93-2.81(m,1H),1.18(d,J=7.2Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=194.42,174.41,150.85,149.87,147.25,136.47,135.91,133.23,107.67,107.05,56.20,42.29,35.83,18.93ppm.HRMS(ESI - ):C 14 H 13 O5Se(MH) - ,340.9934;found,340.9932.

[0066] Example 10 Preparation of 2-methyl-4-oxo-4-(selenophene[2',3':4,5]benzo[1,2-d][1,3]dioxy-6-yl)butyric acid (I-8) The target compound I-8 can be obtained by the same synthesis method as described in Examples 1-3, except that 6-bromobenzo[1,2-d][1,3]dioxole-5-formaldehyde is used as the starting material instead of 2-bromo-4,5-dimethoxybenzaldehyde, and 2-ethyl bromopropionate is used as the reactant instead of 2-ethyl bromoacetate. 1 HNMR(300MHz,DMSO-d6):δ=12.21(s,1H),8.43(s,1H),7.67(s,1H),7.49(s,1H),6.14(s ,2H),3.43-3.36(m,1H),3.10-3.03(m,1H),2.94-2.82(m,1H),1.19(d,J=7.1Hz,3H)ppm.13 CNMR(75MHz,DMSO-d6):δ=193.66,178.84,150.75,146.34,144.29,139.23, 135.11,132.97,109.24,107.14,100.42,42.81,34.38,16.81ppm.HRMS(ESI - ):C 14 H 11 O5Se(MH) - ,338.9777;found,338.9775.

[0067] Example 11 Preparation of 4-(5-ethoxy-6-methoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-9) Referring to the preparation method described in Examples 1-3, the target compound I-9 is obtained by using 2-bromo-5-ethoxy-4-methoxybenzaldehyde instead of 2-bromo-4,5-dimethoxybenzaldehyde as the starting material and 2-bromoethyl propionate instead of 2-ethyl bromoacetate as the reactant, using the same synthesis method. 1 HNMR(300MHz,DMSO-d6):δ=12.20(s,1H),8.41(s,1H),7.69(s,1H),7.50(s,1H),4.09(q,J=6.9Hz,2H),3.85(s ,3H),3.43-3.37(m,1H),3.10-3.03(m,1H),2.92-2.85(m,1H),1.40(t,J=6.9Hz,3H),1.19(d,J=7.2Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.43,176.68,150.50,147.53,144.77,136.75,135.0 7,134.41,109.84,108.01,63.82,55.79,40.88,34.85,17.10,14.69ppm.HRMS(ESI - ):C 16 H 17 O5Se(MH) - ,369.0247;found,369.0244.

[0068] Example 12 Preparation of 4-(5-isopropoxy-6-methoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyric acid (I-10) Referring to the preparation method described in Examples 1-3, the target compound I-10 is obtained by using 2-bromo-5-isopropoxy-4-methoxybenzaldehyde instead of 2-bromo-4,5-dimethoxybenzaldehyde as the starting material and 2-bromoethyl propionate instead of 2-ethyl bromoacetate as the reactant, and by the same synthesis method. 1 HNMR(300MHz,DMSO-d6):δ=12.17(s,1H),8.41(s,1H),7.69(s,1H),7.53(s,1H),4.61-4.53(m,1H),3.84(s,3 H),3.42-3.34(m,1H),3.10-3.02(m,1H),2.92-2.85(m,1H),1.31(d,J=6.0Hz,6H),1.19(d,J=7.2Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.87,177.07,151.93,146.60,145.18,137.40,135.5 8,134.86,113.04,108.82,71.01,56.26,41.32,35.29,22.22,17.51ppm.HRMS(ESI - ):C 17 H 19 O5Se(MH) - ,383.0403;found,383.0401.

[0069] Example 13 [ka] Preparation of ethyl 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxo-butyrate (I-11) 36 mg of compound I-2 (0.1 mmol) was dissolved in 10 mL of ethanol, and 24 mg of thionyl chloride (0.2 mmol) was added dropwise to the reaction mixture in an ice bath. The reaction mixture was then heated to reflux and allowed to react for 4 h. After complete reaction was confirmed by TLC, the solvent was removed under reduced pressure, diluted with 10 mL of water, and extracted twice with 10 mL of ethyl acetate. The combined organic layers were washed with water and saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated. The crude product was purified by silica gel column chromatography to obtain 34 mg of the target compound I-11, with a yield of 89%. 1 HNMR(300MHz,DMSO-d6):δ=8.43(s,1H),7.70(s,1H),7.51(s,1H),4.08(q,J=7.1Hz,2H),3.85(s, 3H),3.82(s,3H),3.44-3.38(m,1H),3.19-3.11(m,1H),2.99-2.88(m,1H),1.20-1.13(m,6H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=192.97,176.42,151.13,146.92,145.19,137.61,135.09,1 33.78,109.95,107.10,62.32,56.12,55.81,42.76,35.28,17.27,16.84ppm.HRMS(ESI + ):C 17 H 21 O5Se(M+H) + ,385.0549;found,385.0548.

[0070] Example 14 [ka] Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-N-hydroxy-2-methyl-4-oxobutanamide (I-12) 177 mg of compound I-2 (0.5 mmol) was dissolved in 10 mL of anhydrous tetrahydrofuran, 160 mg of CDI (1 mmol) was added, and the mixture was stirred at room temperature for 1 h. 69 mg of hydroxylamine hydrochloride (1 mmol) was then added to the reaction mixture, and the mixture was stirred overnight at room temperature. After the reaction was confirmed to be complete by TLC, the mixture was diluted with 10 mL of water and extracted twice with 15 mL of ethyl acetate. The combined organic layers were washed with water and saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated. The crude product was purified by preparative TLC to give 68 mg of the target compound I-12, a 37% yield. 1 HNMR(300MHz,DMSO-d6):δ=10.38(s,1H),8.69(s,1H),8.42(s,1H),7.70(s,1H),7.52(s,1H),3.85(s ,3H),3.82(s,3H),3.46-3.38(m,1H),3.15-3.06(m,1H),2,97-2.88(m,1H),1.19(d,J=7.2Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.16,175.48,150.63,149.07,145.72,137.40,13 6.67,132.81,107.77,107.38,56.15,56.01,43.79,36.94,19.22ppm.HRMS(ESI - ):C 15 H 18 NO5Se(MH) - ,370.0199;found,370.0196.

[0071] Example 15 [ka] Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-methyl-4-oxobutanamide (I-13) 36 mg of compound I-2 (0.1 mmol) and 15 mg of N-methylmorpholine (0.15 mmol) were dissolved in 10 mL of tetrahydrofuran, and 21 mg of isobutyl chloroformate (0.15 mmol) was added dropwise in an ice bath. After the addition was complete, the reaction mixture was warmed to room temperature and stirred for 1 h. The reaction mixture was then placed back in the ice bath, and 0.1 mL of aqueous ammonia was added dropwise. The reaction mixture was then allowed to react at room temperature for 4 h. After the reaction was confirmed to be complete by TLC, the mixture was diluted with 10 mL of water and extracted twice with 15 mL of ethyl acetate. The combined organic layers were washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated. The crude product was purified by silica gel column chromatography to obtain 27 mg of the target compound I-13, with a yield of 76%. 1 HNMR(300MHz,DMSO-d6):δ=8.40(s,1H),7.68(s,1H),7.53(s,1H),7.41(s,1H),6.78(s,1H) ,3.85(s,3H),3.82(s,3H),3.39-3.31(m,1H),2.95-2.82(m,2H),1.12(d,J=6.8Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.87,176.78,150.33,148.36,145.24,136.76,13 5.09,134.24,108.28,107.95,55.81,55.59,41.11,35.46,18.20ppm.HRMS(ESI + ):C 15 H 18 NO4Se(M+H) + ,356.0369;found,356.0366.

[0072] Example 16 Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-ethyl-4-oxo-butyric acid (I-14) Compound I-14 was obtained by the same synthesis method as in Example 3, except that compound X-1 was used as the starting material and 2-ethyl bromoacetate was replaced with ethyl 2-bromobutyrate. 1HNMR(300MHz,DMSO-d6):δ=12.19(s,1H),8.45(s,1H),7.70(s,1H),7.51(s,1H),3.85(s,3H),3.82(s,3H ),3.43-3.37(m,1H),3.11-3.04(m,1H),2.82-2.73(m,1H),1.66-1.56(m,2H),0.95(t,J=7.4Hz,3H)ppm. 13 CNMR(75MHz,CDCl3):δ=192.94,180.36,150.71,148.75,145.37,138.04,135.06 ,133.04,108.27,107.07,56.19,56.05,41.79,39.20,24.95,11.50ppm.HRMS(ESI - ):C 16 H 17 O5Se(MH) - ,369.0247;found,369.0246.

[0073] Example 17 Preparation of R-4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-ethyl-4-oxo-butyric acid (I-15) The target compound I-15 was obtained by the same synthesis method as in Example 5, except that compound X-1 was used as the raw material and ethyl S-2-chloropropionate was used instead of ethyl S-2-chloropropionate as a reactant, with an ee of 95%. 1 HNMR(300MHz,DMSO-d6):δ=12.20(s,1H),8.43(s,1H),7.69(s,1H),7.52(s,1H),3.4(s,3H),3.83(s,3H) ),3.42-3.36(m,1H),3.10-3.04(m,1H),2.83-2.74(m,1H),1.67-1.56(m,2H),0.97(t,J=7.5Hz,3H)ppm. 13 CNMR(75MHz,CDCl3):δ=193.34,180.67,151.50,149.27,144.99,138.72,135.18 ,132.03,108.60,107.63,57.23,56.11,41.59,38.81,25.39,11.05ppm.HRMS(ESI- ):C 16 H 17 O5Se(MH) - ,369.0247;found,369.0244.

[0074] Example 18 Preparation of S-4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-ethyl-4-oxo-butyric acid (I-16) The target compound I-16 was obtained using the same synthesis method as in Example 5, except that compound X-1 was used as the raw material and R-ethyl 2-chloropropionate was used instead of ethyl S-chloropropionate as a reactant, with an ee of 95%. 1 HNMR(300MHz,DMSO-d6):δ=12.19(s,1H),8.44(s,1H),7.69(s,1H),7.52(s,1H),3.85(s,3H),3.83(s,3H ),3.43-3.35(m,1H),3.13-3.02(m,1H),2.83-2.75(m,1H),1.66-1.55(m,2H),0.95(t,J=7.4Hz,3H)ppm. 13 CNMR(75MHz,CDCl3):δ=192.24,181.62,151.74,148.57,144.55,137.85,136.49 ,133.13,109.40,107.23,56.17,55.99,42.28,39.79,25.01,11.84ppm.HRMS(ESI - ):C 16 H 17 O5Se(MH) - ,369.0247;found,369.0246.

[0075] Example 19 Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-isopropyl-4-oxo-butyric acid (I-17) Compound I-17 was obtained using the same synthesis method as in Example 3, except that compound X-1 was used as the raw material and ethyl 2-bromopropionate was used instead of 2-ethyl bromoacetate as the reactant, with an ee of 95%. 1HNMR (300MHz, CDCl3): δ=8.13(s,1H),7.32(s,1H),7.29(s,1H),3.97(s,3H),3.94(s,3H),3. 52-3.43(m,1H),3.06-3.00(m,2H),2.17-2.11(m,1H),1.05(dd,J1=6.8Hz,J2=2.6Hz,6H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=192.98,180.89,150.86,149.61,145.85,138.32,134.6 9,132.20,108.11,106.90,56.25,56.07,48.72,40.68,25.81,22.57ppm.HRMS(ESI - ):C 17 H 19 O5Se(MH) - ,383.0403;found,383.0401.

[0076] Example 20 Preparation of 2-cyclopropyl-4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-4-oxobutyric acid (I-18) Compound I-18 was obtained by the same synthesis method as in Example 3, except that compound X-1 was used as the starting material and 2-bromo-2-cyclopropyl ethyl acetate was used instead of 2-ethyl bromoacetate. 1 HNMR(300MHz,CDCl3):δ=8.28(s,1H),7.35(s,1H),7.31(s,1H),3.98(s,3H),3.96(s,3H),3.5 0-3.41(m,1H),3.10-3.02(m,2H),1.12-1.04(m,1H),0.57-0.49(m,2H),0.21-0.14(m,2H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=194.07,176.11,149.78,147.75 146.69,138.73,135.03,133.12,107.38,107.55,56.10,55.74,47.71,40.95,5.10ppm.HRMS(ESI - ):C 17 H 17 O5Se(MH)- ,381.0247;found,381.0245.

[0077] Example 21 Preparation of 4-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-(methoxymethyl)-4-oxo-butyric acid (I-19) Compound I-19 was obtained by the same synthesis method as in Example 3, except that compound X-1 was used as the starting material and methyl 2-bromo-3-methoxypropionate was used instead of 2-ethyl bromoacetate. 1 HNMR(300MHz,DMSO-d6):δ=12.34(s,1H),8.44(s,1H),7.69(s,1H),7.53(s,1H),3.85(s,3 H),3.82(s,3H),3.60-3.56(m,2H),3.46-3.37(m,1H),3.25(s,3H),3.14-3.07(m,2H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=192.87,179.61,150.43,149.39,144.87,138.76,134.6 6,134.09,108.16,107.55,80.16,60.98,56.30,56.08,39.62,39.04ppm.HRMS(ESI - ):C 16 H 17 O6Se(MH) - ,385.0196;found,385.0195.

[0078] Example 22 Preparation of 2-(2-(5,6-dimethoxybenzo[b]selenophen-2-yl)-2-oxoethyl)hexanoic acid (I-20) Compound I-20 was obtained by the same synthesis method as in Example 3, except that compound X-1 was used as the starting material and ethyl 2-bromohexanoate was used instead of 2-ethyl bromoacetate. 1HNMR(300MHz,CDCl3):δ=8.10(s,1H),7.32(s,1H),7.28(s,1H),3.97(s,3H),3.94(s,3H),3.49- 3.39(m,1H),3.13-3.07(m,2H),1.80-1.57(m,2H),1.37-1.32(m,4H),0.93(t,J=6.7Hz,3H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.85,179.54,150.62,147.88,145.47,138.62,136.00,132. 97,108.83,107.06,56.24,56.05,43.93,42.73,35.03,30.10,24.75,14.48ppm.HRMS(ESI - ):C 18 H 21 O5Se(MH) - ,397.0560;found,397.0558.

[0079] Example 23 [ka]

[0080] Process 1 Preparation of diethyl 2-(5,6-dimethoxybenzo[b]selenophene-2-formyl)glutarate (XII-3) Add 0.17 g of compound X-1 (0.5 mmol), 0.14 g of potassium carbonate (1 mmol), and 5 mL of DMF to a 100 mL reaction flask and stir at room temperature for 30 min. Add 0.14 g of ethyl 3-bromopropionate (0.75 mmol) and 8 mg of potassium iodide (0.05 mmol) to the reaction mixture and stir at 55 °C for 8 h. After monitoring the completion of the reaction by TLC, add 20 mL of water to the reaction mixture and extract twice with 20 mL of ethyl acetate. The combined organic layer was washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to give a yellow oil, which was directly used in the next step without further purification. HRMS (ESI) + ):C 20 H 25O7Se(M+H) + ,457.0760;found,457.0757

[0081] Process 2 Preparation of 5-(5,6-dimethoxybenzo[b]selenophen-2-yl)-5-oxo-valeric acid (I-21) Compound XII-3 obtained in the previous step, 2 mL of concentrated hydrochloric acid, and 2 mL of acetic acid were added to a 100 mL reaction flask and stirred at 100 °C for 3 h. After monitoring the complete reaction of compound XII-3 by TLC, the reaction mixture was cooled to room temperature, diluted with 20 mL of water, and extracted twice with 20 mL of ethyl acetate. The combined organic layers were washed with water and saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain 65 mg of a white solid, for a combined yield of 37% for the two steps. 1 HNMR(300MHz,DMSO-d6):δ=12.01(s,1H),8.38(s,1H),7.69(s,1H),7.51(s,1H),3.85(s, 3H),3.82(s,3H),3.07(t,J=7.4Hz,2H),2.34(t,J=7.5Hz,2H),1.88(t,J=7.1Hz,2H)ppm. 13 CNMR(75MHz,DMSO-d6):δ=193.29,178.96,150.56,148.61,146.46,137.80,13 6.19,134.02,109.54,108.49,56.25,55.98,42.97,31.17,18.41ppm.HRMS(ESI - ):C 15 H 15 O5Se(MH) - ,355.0090;found,355.0088.

[0082] Example 24 [ka] Preparation of 5,6-dimethoxybenzo[b]selenophene (XIII-1) 0.86 g of compound VIII-1 (3 mmol), 0.96 g of 200-mesh copper powder (15 mmol), and 12 mL of quinoline were added to a 100 mL reaction flask and refluxed for 4 h. After monitoring the reaction for completion by TLC, the mixture was filtered under suction. The filtrate was added to 20 mL of 6N hydrochloric acid and stirred at room temperature for 10 min, then extracted twice with 30 mL of ethyl acetate. The combined organic layers were washed with water, saturated brine, dried over anhydrous sodium sulfate, filtered under suction, and concentrated to obtain the crude product. This was further purified by silica gel column chromatography to obtain 0.59 g of compound VIII-1 as a white solid in 81% yield. 1 HNMR (300MHz, DMSO-d6): δ=7.54(s,1H),7.52(d,J=5.3Hz,1H),7.37(s,1H),7.29(d,J=5.3Hz,1H),3.81(s,3H),3.80(s,3H)ppm.

[0083] Example 25 [ka] Preparation of 2-(5,6-dimethoxybenzo[b]selenophene-2-formyl)cyclopropane-1-carboxylic acid (I-22) 0.24 g of compound I-22 (1 mmol), 0.28 g of 3-oxabicyclo[3.1.0]hexane-2,4-dione (2.5 mmol), and 5 mL of dichloromethane were added to a 100 mL reaction flask and stirred at 0 °C for 1 h. Then, 0.2 g of aluminum trichloride (1.5 mmol) was added to the reaction mixture and stirred at room temperature overnight. After monitoring the reaction completion by TLC, 10 mL of 1 N hydrochloric acid was added to the reaction mixture and extracted twice with 20 mL of ethyl acetate. The combined organic layers were washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, suction filtered, and concentrated to obtain the crude product. After further purification by silica gel column chromatography, 102 mg of compound I-22 was obtained as a pale yellow solid in 29% yield. 1HNMR (300MHz, DMSO-d6): δ=12.24(s,1H),8.45(s,1H),7.69(s,1H),7.55(s,1H),3.85(s,3H),3. 83(s,3H),3.07(q,J=8.4Hz,1H),2.30(q,J=8.0Hz,1H),2.17-2.01(m,1H),1.56-1.50(m,1H)ppm. 13 CNMR(75MHz,CDCl3):δ=194.01,176.93,150.61,147.58,145.89,138.82,135 .66,131.91,108.20,107.44,56.30,56.11,27.92,19.82,11.53ppm.HRMS(ESI - ):C 15 H 13 O5Se(MH) - ,352.9934;found,352.9931.

[0084] Example 26 Preparation of 2-(5,6-dimethoxybenzo[b]selenophene-2-formyl)cyclobutane-1-carboxylic acid (I-23) Using the same synthesis method as in Example 25, compound XIII-1 was used as the starting material, except that cyclobutane-1,4-dicarboxylic anhydride was used instead of 3-oxabicyclo[3.1.0]hexane-2,4-dione as the reactant. 58 mg of target compound I-23 was obtained as a pale yellow solid, with a yield of 32%. 1 HNMR(300MHz,CDCl3):δ=7.92(s,1H),7.31(s,1H),4.32-4.24(m,1H),3.96(s, 3H),3.93(s,3H),3.58-3.50(m,1H),2.54-2.44(m,2H),2.41-2.26(m,2H)ppm. 13 CNMR(75MHz,CDCl3):δ=193.91,177.88,150.59,148.67,144.65,138.01,135.06 ,132.57,108.26,107.07,56.19,56.04,44.40,40.79,23.13,22.27ppm.HRMS(ESI - ):C 16 H15 O5Se(MH) - ,367.0090;found,367.0089.

[0085] Example 27 Preparation of 2-(5,6-dimethoxybenzo[b]selenophene-2-formyl)cyclohexane-1-carboxylic acid (I-24) Using the same synthesis method as in Example 25, compound XIII-1 was used as the starting material, except that 1,2-cyclohexanedicarboxylic anhydride was used instead of 3-oxabicyclo[3.1.0]hexane-2,4-dione as a reactant. 37 mg of target compound I-24 was obtained as a pale yellow solid, with a yield of 19%. 1 HNMR(300MHz,DMSO-d6):δ=12.20(s,1H),8.44(s,1H),7.70(s,1H),7.55(s,1H),3.85(s,3H) ,3.83(s,3H),2.66-2.60(m,1H),2.58-2.53(m,1H),1.85-1.56(m,4H),1.49-1.30(m,4H)ppm. 13 CNMR(75MHz, CDCl3):δ=193.76,176.12,150.56,148.95,145.01,137.94,135.13,132.2 9,109.16,107.13,56.24,56.06,48.22,42.50,26.26,26.07,25.87,23.71ppm.HRMS(ESI - ):C 18 H 19 O5Se(MH) - ,395.0403;found,395.0400.

[0086] Example 28 Luciferase reporter gene experiments based on THP1-Lucia and RAW-Lucia THP1-dual TM (Invivogen:thpd-nfis) cells or RAW-Lucia TM(Invivogen:rawl-isg) cells were diluted with medium, and 180 μL of the cell suspension was aspirated and inoculated into a 96-well plate, with 1 × 10 cells per well. 5 Then, 20 μL of the test compound was added to a 96-well plate (final compound concentration was 10 μM, final volume of each well was 200 μL), and 37 o Incubate at 4°C for 24 hours. Then, pipette 10 μL of the supernatant into a new 96-well white plate and add 50 μL of QUANT-Luc reagent. After thorough homogeneity, immediately measure using a microplate reader. Three replicate wells are set up for each experiment. The test results are expressed as an activation fold, calculated as (test well - blank well) / (negative well - blank well). The test results are shown in the table below, with 2',3'-cGAMP as the positive control. Here, *** represents an activation fold of 20 or more, ** represents an activation fold of 10-20, and * represents an activation fold of 1-10.

[0087] [Table 1]

[0088] As can be seen from Table 1, the compounds according to the present invention have high agonistic activity against the cGAS-STING pathway.

[0089] Example 29 Interferon β induction experiment based on THP1 cells The secretion of the cytokine IFNβ was measured by enzyme-linked immunosorbent assay (ELISA). THP1 cells were seeded into 96-well plates (in RPMI 1640 medium without serum), and the number of cells in each well was 5–7 × 10 5The test compound was prepared in a 10 mM MDMSO stock solution, diluted to the target concentration with culture medium, and added to the 96-well plate containing the cells (final compound concentration: 20 μM, final volume per well: 200 μL). The mixture was then incubated at 37°C, 5% CO2 for 3.5 hours. The cells were then collected and centrifuged at 1000 rpm for 20 minutes at 4°C. The supernatant was collected and used for ELISA assays. Three replicate wells were used per experiment. The results are shown in the table below. 2',3'-cGAMP was used as a positive control, and the test results were expressed as percentage activity relative to 20 μM 2',3'-cGAMP.

[0090] [Table 2]

[0091] As can be seen from Table 2, the representative compounds of the present invention have high activity in inducing IFNβ secretion from THP1 cells.

[0092] Example 30 ADMET property evaluation of some compounds of the present invention This example evaluated the ADMET properties of some preferred compounds, including water solubility, LogP, 2-hour mouse liver microsomal stability, 24-hour human plasma stability, THP1 cell growth inhibitory activity, and predicted membrane permeability. The test results are shown in the table below, with MSA2 (Science. 2020, 369, eaba6098) as the reference compound.

[0093] [Table 3]

[0094] As can be seen from Table 3, representative compounds of the present invention have high ADMET properties.

Claims

1. A compound represented by general formula (I), a stereoisomer or a pharmaceutically acceptable salt thereof: 【Chemical 1】 During the ceremony, R １ is a hydrogen atom, R ２ is a hydrogen atom or OR ６ Selected from R ３ is a hydrogen atom or OR ６ Selected from Or, R ２ and R ３ can form, together with the atoms to which it is connected, a 5- or 6-membered heterocyclic ring containing 1 to 2 ring members selected from O, S, or N; R ４ is a hydrogen atom, R ５ is a hydrogen atom, X １ is C(O), X ２ is CHR ７ CHR ７ and X ３ is COOR ６ , C(O)N(R ６ ) ２ or C(O)NHOH, Each R ６ are independently a hydrogen atom, C １ ~C ３ Alkyl group, or C １ ~C ３ haloalkyl groups, R ７ are the same or different, and each R ７ are independently a hydrogen atom, a fluorine atom, or C １ ~C ４ Alkyl group, C １ ~C ４ Haloalkyl group, C ３ ~C ６ Cycloalkyl group or OC １ ~C ３ C substituted with alkyl group １ ~C ４ alkyl group, or two R ７ forms a 3- to 6-membered ring together with the atoms to which it is connected.

2. A compound represented by general formula (I-1), a stereoisomer or a pharmaceutically acceptable salt thereof: 【Chemistry 2】 In the formula, X ２ is CHR ７ CHR ７ and R ７ are the same or different, and each R ７ are independently a hydrogen atom, a fluorine atom, CN, C １ ~C ４ Alkyl group, C １ ~C ４ Haloalkyl group, OR ６ C substituted with １ ~C ４ Alkyl group, C ３ ~C ６ cycloalkyl groups, or two R groups on different carbon atoms ７ can form a 3- to 6-membered ring together with the atoms to which it is connected, R ６ are independently a hydrogen atom or C １ ~C ３ It is selected from alkyl groups.

3. The following compound, stereoisomer or pharmaceutically acceptable salt thereof: 【Chemistry 3】

4. When the compound is a compound represented by general formula (Ia), a compound of general formula (IV) is produced by a substitution reaction between a compound of general formula (II) and a compound (III) under alkaline conditions, a compound (VI) is produced by a substitution reaction between compound (IV) and compound (V), a compound (VII) is produced by an intramolecular condensation reaction of compound (VI) under alkaline conditions, a compound (VIII) is produced by a hydrolysis reaction of compound (VII), a compound (X) is produced by a condensation reaction of compound (VIII) and compound (IX), a compound (XII) is produced by a nucleophilic substitution reaction between compound (X) and compound (XI), and a compound (XII) is produced by a hydrolysis decarboxylation reaction to produce a compound of general formula (Ia), and the synthetic route is as follows: 【Chemistry 4】 In the formula, R ２ , R ３ and R ７ is as defined in claim 1, and R ８ is CH ３ , C.H. ２ CH ３ , C(CH ３ ) ３ Selected from R ９ is CH ３ , C.H. ２ CH ３ X is selected from Cl, Br, and I; When the compound is a compound represented by general formula (Ib), compound (XIII) is produced by decarboxylation of compound represented by general formula (VIII), and compound (XIII) and compound (XIV) are subjected to Friedel-Crafts acylation to produce compound (Ib) of the general formula, and the synthesis route is as follows: 【Chemistry 5】 In the formula, R ２ and R ３ is as defined in claim 1, and n represents 1, 2, 3 or 4. A method for producing the compound according to claim 1.

5. A pharmaceutical composition comprising a pharmaceutically effective amount of an active ingredient and a pharmaceutically acceptable excipient, wherein the active ingredient comprises one or more of the compounds, stereoisomers or pharmaceutically acceptable salts thereof described in any one of claims 1 to 3.

6. Use of a compound, stereoisomer or pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 or a pharmaceutical composition according to claim 5 in the manufacture of a drug that activates the cGAS-STING pathway.

7. Use of a compound, stereoisomer or pharmaceutically acceptable salt thereof described in any one of claims 1 to 3 or a pharmaceutical composition described in claim 5 in the manufacture of a drug for treating a disease associated with STING pathway activity.

8. The use of claim 7, wherein the disease associated with STING pathway activity is one or more of an autoimmune disease, an infectious disease, a cancer, and a disease associated with a precancerous syndrome.

9. Use of the compound, stereoisomer or pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 or the pharmaceutical composition according to claim 5 in the manufacture of an immune adjuvant.

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