A tricyclic compound, pharmaceutical composition thereof and use thereof

Abstract

The application discloses a tricyclic compound as shown in general formula I or an enantiomer, a diastereomer, a racemate and a pharmaceutically acceptable salt thereof, a pharmaceutical composition thereof, the compound has strong STING agonistic activity in THP1-Dual cells, can be used for preparing a medicine for treating diseases related to the function of STING protein, has the prospect of being used for preparing a medicine for treating inflammatory diseases, autoimmune diseases, infectious diseases or tumor-related diseases, and provides a reliable way for clinical application.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to a tricyclic compound, its pharmaceutical composition, and its uses. This type of compound exhibits strong STING agonist activity in THP1-Dual cells. Background Technology

[0002] The cGAS-STING signaling pathway, as an innate cytoplasmic DNA sensing pathway, has attracted much attention due to its ability to activate innate and adaptive immunity and participate in the host's defense against cancer. Specifically, cGAS is considered an innate immune sensor of cytoplasmic double-stranded DNA (dsDNA), possessing a catalytic domain and two major DNA binding sites. In the absence of dsDNA, cGAS remains in a catalytically inactive state. However, both extrinsic and intrinsic dsDNA can bind to cGAS in a sequence-independent manner through the interaction between its phosphate backbone and the positively charged site of cGAS, forming a 2:2 complex. In the dsDNA-bound cGAS dimer, each dsDNA molecule interacts with two cGAS protons through the two binding sites, with the dsDNA molecule sandwiched between the cGAS protons. Upon binding to dsDNA, cGAS undergoes a significant conformational change within the catalytic pocket, which contributes to cGAS activation. Once cGAS is activated, it can catalyze the synthesis of the second messenger 2'3'-cGAMP from adenosine triphosphate (ATP) and guanosine triphosphate (GTP) in the body. cGAMP is the endogenous ligand of the STING protein.

[0003] STING (also known as TMEM173, MPYS, ERIS, MITA, molecular weight 42kDa) is a recognition receptor located on the endoplasmic reticulum (ER) membrane. As a central part of cytoplasmic immune surveillance, it is activated by recognizing cGAMP synthesized endogenously via cGAS. In the resting state, the STING dimer is in an inactive state. When cGAMP induces binding to the LBD domain of the STING dimer, a conformational change occurs, leading to the release of CTT and exposure of the STING polymerization interface. This allows STING to assemble into oligomers in a parallel arrangement, with the dimer as the unit. After binding to cGAMP, the ER-bound STING dimer undergoes a significant transition from an inactive open conformation to an active closed conformation. Besides cGAMP, bacterial cyclic dinucleotides (CDNs) such as c-di-AMP, c-di-GMP, and 3',3'-cGAMP can also activate STING in the same way, triggering its translocation from the ER to the Golgi apparatus. During translocation, the Cys88 and Cys91 residues of the STING protein NTD domain undergo palmitoylation, releasing CTTs to promote self-oligomerization. In the Golgi apparatus, STING is phosphorylated by recruited TBK1, thereby recruiting interferon regulator 3 (IRF3). After IRF3 is phosphorylated by TBK1, the dimer enters the nucleus, driving the expression of type I interferon. In addition, to a lesser extent, STING can also activate IκB kinase (IKK), which phosphorylates the nuclear factor NFκB inhibitor IκBα, leading to the translocation of NFκB to the nucleus, thereby expressing pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor (TNF).

[0004] In summary, STING protein is a key adaptor protein in the innate immune response. Activation of STING can enhance the immune effects of immunotherapy, thereby more broadly stimulating and strengthening the body's innate and adaptive immune functions. Therefore, STING agonists hold promise for use in various cancer patients and even for treating other diseases beyond cancer.

[0005] WO2022169921A1 discloses a STING agonist, which has the following structural formula:

[0006]

[0007] Cherney et al. from Bristol-Myers Squibb (J. Med. Chem. 2022, 65, 4, 3518–3538) have demonstrated that ester compounds of this type of STING agonist molecule exhibit poor stability in liver microsomes as prodrug molecules, while the acidic parent compounds are highly polar and cannot penetrate cell membranes. Therefore, this class of compounds still has significant potential for modification and optimization. Summary of the Invention

[0008] Objective of the Invention: One objective of this invention is to provide a tricyclic compound of general formula I, or its enantiomers, diastereomers, racemates, and pharmaceutically acceptable salts thereof.

[0009]

[0010] in,

[0011] R1, R2, R3, and R4 are each independently selected from hydrogen, halogen, hydroxyl, haloalkanes, cyano, nitro, formyl, carbamoyl, C1-C3 alkyl, C1-C3 alkoxy, C2-C3 alkenyl, or alkynyl.

[0012] R5 is selected from hydrogen, C1-C 18 Alkyl or haloalkanes;

[0013] X1 is selected from N, O, S, or Se;

[0014] X2 is selected from N, C or O.

[0015] In some preferred embodiments,

[0016] R1 is selected from hydrogen;

[0017] R2 is selected from hydrogen, halogen, nitro, cyano, C1-C3 alkyl, carbamoyl, or trifluoromethyl;

[0018] R3 is selected from hydrogen, halogen, or C1-C3 alkyl;

[0019] R4 is selected from hydrogen or halogen;

[0020] R5 is selected from hydrogen or C1-C3 alkyl;

[0021] X1 is selected from N or O;

[0022] X2 is selected from N or C.

[0023] In some preferred embodiments, the pharmaceutically acceptable salt includes acid addition salts formed by compounds of general formula I with the following acids: hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, acetic acid, citric acid, fumaric acid, tartaric acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, lactic acid, pyruvic acid, maleic acid or succinic acid, salicylic acid, phenylacetic acid, malic acid, and mandelic acid; and also includes acid salts formed by compounds of general formula I with inorganic bases.

[0024] In some further preferred embodiments, the pharmaceutically acceptable salt includes basic metal cation salts, alkaline earth metal cation salts, and ammonium cation salts.

[0025] The compounds of general formula I of the present invention are preferably the following compounds:

[0026]

[0027]

[0028] The compounds of general formula I mentioned above in this invention can also exist in the form of their salts, which are converted into compounds of general formula I in vivo. For example, within the scope of this invention, the compounds of this invention are converted into pharmaceutically acceptable salt forms according to processes known in the art, and used in salt form.

[0029] All tautomers of compounds of general formula I of this invention are included within the scope of this invention. The compounds of this invention may exist in specific geometric or stereoisomer forms. Additional asymmetric carbon atoms may be present in alkyl or other substituents; all such isomers and mixtures thereof are included within the scope of this invention.

[0030] This invention also provides synthetic routes for compounds having general formula I:

[0031] (1) When X1 is selected from oxygen, X2 is selected from carbon, R1 is selected from hydrogen, R2 is selected from hydrogen, halogen, nitro, cyano, methyl, carbamoyl, trifluoromethyl, R3 is selected from hydrogen, halogen, methyl, R4 is selected from H, and R5 is selected from methyl, the synthetic route of the compound is as follows:

[0032]

[0033] Reagents and conditions: (a) Ammonium chloride T, sodium iodide, N,N-dimethylformamide, room temperature, 6 h; (b) N-Boc-aminopropyne, cuprous iodide, palladium dichloride of bis(triphenylphosphine), triethylamine, nitrogen, 85 °C, 3 h; (c) Trifluoroacetic acid, dichloromethane, room temperature, 2 h; (d) Anhydrous magnesium sulfate, dry methanol, dry dichloromethane, room temperature, 6 h, sodium borohydride, 0 °C, 2 h; (e) O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate, N-methylmorpholine, N,N-dimethylformamide, room temperature, 4 h.

[0034] (2) When X1 is selected from oxygen, X2 is selected from carbon, R1 is selected from hydrogen, R2 is selected from hydrogen, halogen, nitro, cyano, methyl, carbamoyl, trifluoromethyl, R3 is selected from hydrogen, halogen, methyl, R4 is selected from H, and R5 is selected from hydrogen, the synthetic route of the compound is as follows:

[0035]

[0036] Reagents and conditions: (a) Ammonium chloride T, sodium iodide, N,N-dimethylformamide, room temperature, 6 h; (b) N-Boc-aminopropyne, cuprous iodide, bis(triphenylphosphine)palladium dichloride, triethylamine, nitrogen, 85 °C, 3 h; (c) Trifluoroacetic acid, dichloromethane, room temperature, 2 h; (d) Anhydrous magnesium sulfate, dry methanol, dry dichloromethane, room temperature, 6 h, sodium borohydride, 0 °C, 2 h; (e) O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate, N-methylmorpholine, N,N-dimethylformamide, room temperature, 4 h; (f) Lithium hydroxide monohydrate, tetrahydrofuran, methanol, water, 60 °C, 1 h, dilute hydrochloric acid.

[0037] (3) When X1 is selected from oxygen, X2 is selected from carbon, R1 is selected from hydrogen, R2 is selected from hydrogen, halogen, nitro, cyano, methyl, carbamoyl, trifluoromethyl, R3 is selected from hydrogen, halogen, methyl, R4 is selected from chlorine or bromine, and R5 is selected from methyl, the synthetic route of the compound is as follows:

[0038]

[0039] Reagents and conditions: (a) Ammonium chloride T, sodium iodide, N,N-dimethylformamide, room temperature, 6 h; (b) N-Boc-aminopropyne, cuprous iodide, palladium dichloride bis(triphenylphosphine), triethylamine, nitrogen, 85 °C, 3 h; (c) methoxy(cyclooctadiene)iridium dimer, 4,4'-di-tert-butyl-2,2'-bipyridine, pinacol diborate, anhydrous ethylene glycol dimethyl ether, 80 °C, 6 h; (d) (e) Copper chloride or copper bromide, methanol, 50°C, 8h; (f) Trifluoroacetic acid, dichloromethane, room temperature, 2h; (g) Anhydrous magnesium sulfate, dry methanol, dry dichloromethane, room temperature, 6h, sodium borohydride, 0°C, 2h; (c) O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate, N-methylmorpholine, N,N-dimethylformamide, room temperature, 4h.

[0040] (4) When X1 is selected from oxygen, X2 is selected from carbon, R1 is selected from hydrogen, R2 is selected from hydrogen, halogen, nitro, cyano, methyl, carbamoyl, trifluoromethyl, R3 is selected from hydrogen, halogen, methyl, R4 is selected from chlorine or bromine, and R5 is selected from hydrogen, the synthetic route of the compound is as follows:

[0041]

[0042] Reagents and conditions: (a) Ammonium chloride T, sodium iodide, N,N-dimethylformamide, room temperature, 6 h; (b) N-Boc-aminopropyne, cuprous iodide, palladium dichloride bis(triphenylphosphine), triethylamine, nitrogen, 85 °C, 3 h; (c) methoxy(cyclooctadiene)iridium dimer, 4,4'-di-tert-butyl-2,2'-bipyridine, pinacol diborate, anhydrous ethylene glycol dimethyl ether, 80 °C, 6 h; (d) copper chloride or copper bromide, methanol, 50 °C, 8 h. h; -z(e) Trifluoroacetic acid, dichloromethane, room temperature, 2h; (f) Anhydrous magnesium sulfate, dry methanol, dry dichloromethane, room temperature, 6h, sodium borohydride, 0℃, 2h; (g) O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate, N-methylmorpholine, N,N-dimethylformamide, room temperature, 4h; (h) Lithium hydroxide monohydrate, tetrahydrofuran, methanol, water, 60℃, 1h, dilute hydrochloric acid.

[0043] The compounds of general formula I of this invention can be prepared by the methods described above or similarly described, with the appropriate starting materials selected according to the different substituents and their positions. Those skilled in the art should recognize that the above-described route helps in understanding this invention, but does not limit its scope; unless otherwise specified, variables are defined as mentioned in general formula I.

[0044] Another object of the present invention is to provide a pharmaceutical composition comprising a compound of general formula I or a pharmaceutically acceptable salt thereof, an enantiomer, a diastereomer, a racemic mixture thereof, and a pharmaceutically acceptable carrier.

[0045] The pharmaceutical compositions of the present invention can be administered in various known ways, such as orally, parenterally, by inhalation spray, or via an implanted reservoir. The pharmaceutical compositions of the present invention can be administered alone or in combination with other drugs. Oral compositions can be any orally acceptable dosage form, including, but not limited to, tablets, capsules, emulsions, suspensions, dispersions, and solutions. Commonly used pharmaceutically acceptable carriers or excipients include stabilizers, diluents, surfactants, lubricants, antioxidants, binders, colorants, fillers, emulsifiers, etc.

[0046] Sterile injectable compositions may be formulated using suitable dispersants or wetting agents and suspending agents in accordance with techniques known in the art. Pharmaceutically acceptable carriers and solvents that may be used include water, mannitol, sodium chloride solution, etc.

[0047] Topical compositions can be formulated as oils, lotions, creams, etc. Carriers used in the compositions include vegetable or mineral oils, animal fats, and high molecular weight alcohols. Pharmaceutically acceptable carriers are those in which the active ingredient is soluble.

[0048] The actual dosage level of the active ingredient in the pharmaceutical composition of the present invention can be varied to obtain an amount of active ingredient that is effective in achieving the desired therapeutic response for a particular patient, composition, and route of administration, and is non-toxic to the patient. The selected dosage level depends on a variety of factors, including the activity of the specific compound of the present invention or its salt used, the route of administration, the time of administration, the excretion rate of the specific composition used, the duration of treatment, other drugs, compounds, and / or materials used in combination with the specific composition used, the age, sex, weight, general health condition, and medical history of the patient being treated, and similar factors known in the medical field.

[0049] Another object of the present invention is to provide the use of compounds of general formula I or pharmaceutically acceptable salts thereof, their enantiomers, diastereomers, and racemates in the preparation of medicaments for treating diseases related to the function of the STING protein.

[0050] The diseases associated with STING protein function are one or more of the following: inflammation, autoimmune diseases, infectious diseases, or tumors.

[0051] The tumor-related diseases mentioned are selected from colon cancer, gastric cancer, breast cancer, fibrosarcoma, squamous cell carcinoma, lung cancer, melanoma, ovarian cancer, brain cancer, spinal cancer, liver cancer, cervical cancer, head and neck cancer, leukemia, blood cancer, skin cancer, reproductive system cancer, lung cancer, malignant mesothelioma, sarcoma, lymphoma, adenocarcinoma, thyroid cancer, cardiac tumors, germ cell tumors, gastrointestinal cancers, liver cancer, bile duct cancer, kidney cancer, bladder cancer, or bone cancer.

[0052] Beneficial effects:

[0053] The tricyclic compounds of this invention exhibit strong STING agonist activity in THP1-Dual cells, enabling the preparation of drugs for treating diseases related to STING protein function. They hold promise for the preparation of drugs for treating inflammatory, autoimmune, infectious, or tumor-related diseases, providing a reliable pathway for clinical application. Attached Figure Description

[0054] Figure 1 Figure 1 shows the thermal shift assay (TSA) results of compounds 22, 29, and STING protein. Detailed Implementation

[0055] The technical solution of the present invention will be described in detail below through specific embodiments, but the scope of protection of the present invention is not limited to the embodiments described.

[0056] The starting materials and reaction reagents used in the specific embodiments of this invention are all commercially available. This invention can be prepared into a salt form using methods commonly used in the art, such as: dissolving the compound in hydrochloric acid-ethanol at room temperature to generate hydrochloride; or adding benzenesulfonic acid to generate benzenesulfonate.

[0057] Experimental methods in the embodiments of this invention that do not specify specific conditions are generally performed under conventional conditions or under conditions recommended by the raw material or product manufacturer.

[0058] Synthesis of 4-formylpyrazolo[1,5-a]pyridine-3-carboxylic acid (intermediate m)

[0059]

[0060] Step 1: Synthesis of intermediate m-2

[0061] Hydroxylamine-O-sulfonic acid (3.13 g, 27.49 mmol) was dissolved in water. A saturated sodium bicarbonate solution was added under ice bath (0 °C) conditions to adjust the pH to 8. Then, a methanol solution (15 mL) of 3-pyridinemethanol (1.5 g, 13.75 mmol) was added, and the mixture was heated to 50 °C and reacted for 16 h. The solvent was removed by rotary evaporation of the reaction solution (toluene was added and the solution was repeatedly rotary evaporated to remove water). Under ice bath (0 °C), 30 mL of DMF, methyl propynate (1.27 g, 15.12 mmol), and anhydrous K₂CO₃ (5.7 g, 41.25 mmol) were added, and the mixture was reacted at room temperature for 2 h. After the reaction was complete, the solution was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and prepared into a precipitate. The precipitate was separated by silica gel column chromatography (petroleum ether:ethyl acetate = 30:1, v / v) to obtain intermediate m-2, 1.35 g of a pale yellow solid (yield 47.63%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.74-8.68 (m, 1H), 8.41 (s, 1H), 7.61 (dd, J = 7.3, 1.3H z,1H),7.17-7.07(m,1H),5.36(t,J=5.6Hz,1H),5.01(d,J=5.6Hz,2H),3.76(s,3H).

[0062] Step 2: Synthesis of intermediate m-3

[0063] Intermediate m-2 (200 mg, 0.97 mmol) was added to 15 mL of acetonitrile under ice bath (0 °C), followed by the addition of Desmartin oxidant (494 mg, 1.16 mmol). The mixture was stirred at room temperature for 2.5 h. Then, 20 mL of saturated sodium bicarbonate aqueous solution and sodium thiosulfate solid (183.4 mg, 1.16 mmol) were added sequentially, and the mixture was stirred for 0.5 h. After removing acetonitrile by rotary evaporation, the mixture was extracted with ethyl acetate, concentrated under vacuum, and separated by silica gel column chromatography (petroleum ether:ethyl acetate = 50:1, v / v) to obtain intermediate m-3, 163 mg of yellow solid (yield 82.30%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.00 (d, 1H), 9.22 (dd, J = 6.8, 1.2Hz, 1H), 8.68 (s, 1H), 8.10 (dd, J = 7.3, 1.1Hz, 1H), 7.42-7.33 (m, 1H), 3.89 (s, 3H).

[0064] Step 3: Synthesis of intermediate m

[0065] Intermediate m-3 (163 mg, 0.798 mmol) was placed in a round-bottom flask, and 5 ml each of methanol, tetrahydrofuran, and water were added. Lithium hydroxide monohydrate (100 mg, 2.39 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was completed by TLC monitoring, some of the solvent was removed by rotary evaporation, and dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to around 5. A solid precipitated out, which was filtered, and the filter cake was dried to obtain the desired compound m, a light yellow solid powder of 143 mg (yield 94.31%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 12.79 (s, 1H), 11.05 (s, 1H), 9.16 (dd, J = 6.8, 1.1Hz, 1H), 8.60 (s, 1H), 8.03 (dd, J = 7.3, 1.1Hz, 1H), 7.31 (t, J = 7.0Hz, 1H).

[0066] Example 1: Synthesis of methyl 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (Compound 1)

[0067]

[0068] Step 1: Synthesis of intermediates 1-2

[0069] Intermediate 1-1 (1 g, 4.6 mmol) was dissolved in methanol (20 ml), and 0.5 ml of concentrated H2SO4 was added. The mixture was heated to 80 °C and reacted for 8 h. After the reaction was completed by TLC, the mixture was cooled to room temperature, and saturated NaHCO3 aqueous solution was slowly added dropwise under ice bath (0 °C) to adjust the pH to approximately 8.5. The mixture was extracted with ethyl acetate, and the organic phase was concentrated. The organic phase was then purified by silica gel column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to obtain 800 mg of a colorless oil, which is intermediate 1-2. 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.85 (ddd, J = 14.9, 7.9, 1.6 Hz, 2H), 6.92 (t, J = 7.9 Hz, 1H), 3.94 (s, 3H).

[0070] Step 2: Synthesis of intermediates 1-3

[0071] Intermediate 1-2 (700 mg, 3.08 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (470 mg, 3.08 mmol), CuI (30 mg, 0.15 mmol), and Pd(PPh3)2Cl2 (220 mg, 0.308 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by silica gel column chromatography (petroleum ether: ethyl acetate = 30:1, v / v) to obtain intermediate 1-3, 530 mg. 1 H NMR(300MHz,DMSO-d6)δ(ppm)7.97(dd,J=7.7,1.3Hz,1H),7.90(dd,J=7.7,1.3Hz,1H),7.66(t,J = 5.9Hz, 1H), 7.43 (t, J = 7.7Hz, 1H), 6.85 (s, 1H), 4.41 (d, J = 5.9Hz, 2H), 3.99 (s, 3H), 1.48 (s, 9H).

[0072] Step 3: Synthesis of intermediates 1-4

[0073] Intermediate 1-3 (500 mg, 1.64 mmol) was placed in a round-bottom flask, and 4 ml of dichloromethane and 1 ml of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to approximately 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 1-4, which did not require purification and was reserved for further use.

[0074] Step 4: Synthesis of intermediates 1-5

[0075] Intermediates 1-4 (300 mg, 1.46 mmol) and m (278 mg, 1.46 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (175 mg, 1.46 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (111 mg, 2.92 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was separated by silica gel column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediates 1-5, 289 mg of white solid (yield 56.23%). 1H NMR (300MHz, DMSO-d6) δ (ppm) 8.78-8.69 (m, 1H), 8.40 (s, 1H), 7.85 (ddd, J=15.5, 7.7, 1.3Hz, 2H), 7.56 (d, J= 7.0Hz,1H),7.35(t,J=7.7Hz,1H),7.07(t,J=7.0Hz,1H),6.88(s,1H),4.36(s,2H),3.98(s,2H),3.93(s,3H).

[0076] Step 5: Synthesis of Compound 1

[0077] Intermediate 1-5 (50 mg, 0.13 mmol) was dissolved in 5 mL of DMF, and HATU (61.2 mg, 0.161 mmol) and NMM (17 mg, 0.161 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was completed by TLC monitoring, silica gel column chromatography (dichloromethane:methanol = 100:100) was performed.

[0078] 1. Separation by volume ratio yielded the target product compound 1, 34 mg of white solid (yield 72.38%, purity 96.65%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.70(d,J=6.9Hz,1H),8.33(s,1H),7.86(ddd,J=14.8,7.7,1.3Hz,2H),7.40-7 .25(m,2H),7.08(t,J=6.9Hz,1H),6.98(d,J=1.0Hz,1H),5.20-5.13(m,2H),5.00-4.88(m,2H),3.89(s,3H).

[0079] Example 2: Synthesis of methyl 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthid-4(5H)-yl)methyl)-1H-benzimidazole-4-carboxylic acid (compound 2)

[0080]

[0081] Step 1: Synthesis of intermediate 2-2

[0082] N-Benzyloxycarbonylglycine (1.5 g, 7.22 mmol) was dissolved in 30 mL of DMF, and HATU (2.0 g, 7.826 mmol) and DIPEA (1.6 mL, 9.03 mmol) were added. After stirring for 0.5 h, intermediate 2-1 (1.0 g, 6.02 mmol) was added, and the reaction was carried out at room temperature for 8 h. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, concentrated the organic phase, and purified by silica gel column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give 1.76 g of the intermediate as a white solid.

[0083] The obtained intermediate (1.1 g) was dissolved in 10 mL of glacial acetic acid and reacted at 65 °C for 1 h. After the reaction was complete, acetic acid was removed by rotary evaporation, diluted with water, extracted with ethyl acetate, and the organic phase was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 80:1, v / v) to give intermediate 2-2, 860 mg of white solid (two-step yield 75.06%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 12.26 (s, 1H), 7.90 (d, J = 7.3Hz, 2H), 7.82 (dd, J = 7.7, 1.1Hz, 1H) ,7.39(t,J=4.4Hz,5H),7.32(d,J=7.9Hz,1H),5.09(s,2H),4.55(d,J=6.0Hz,2H),3.97(s,3H).

[0084] Step 2: Synthesis of intermediates 2-3

[0085] Intermediate 2-2 (500 mg, 1.45 mmol) was dissolved in 10 mL of ethanol, and Pd / C (200 mg) was added. The mixture was then purged with hydrogen and reacted at room temperature for 4 h. After the reaction was complete as monitored by TLC, Pd / C was removed by diatomaceous earth filtration. The filtrate was concentrated to obtain crude intermediate 2-3, which did not require purification and was reserved for further use.

[0086] Step 3: Synthesis of intermediates 2-4

[0087] Intermediate 2-3 (199 mg, 0.97 mmol) and intermediate m (184.5 mg, 0.97 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (116.4 mg, 0.97 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (73.4 mg, 1.94 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by silica gel column chromatography (dichloromethane:methanol = 20:1, v / v) to obtain intermediate 2-4, a white solid of 186 mg (yield 50.31%).

[0088] 1 H NMR (300MHz, DMSO-d6) δ (ppm) 12.26 (s, 1H), 8.72 (d, J = 6.9Hz, 1H), 8.38 (s, 1H), 7.88 (d, J = 7.7Hz, 1H), 7.80 (d, J = 7. 5Hz, 1H), 7.47 (d, J = 7.1Hz, 1H), 7.29 (t, J = 7.8Hz, 1H), 7.04 (d, J = 7.0Hz, 1H), 4.33 (s, 2H), 4.07 (s, 2H), 3.95 (s, 3H).

[0089] Step 4: Synthesis of Compound 2

[0090] Intermediate 2-4 (50 mg, 0.132 mmol) was dissolved in 5 mL of DMF, and HATU (61.2 mg, 0.161 mmol) and NMM (17 mg, 0.161 mmol) were added. The mixture was reacted at room temperature for 4 h. After the reaction was completed by TLC monitoring, the product was separated by silica gel column chromatography (dichloromethane:methanol = 100:1, v / v) to give the target product compound 2, 24 mg of white solid (yield 50.39%, purity 97.73%). 1 ¹H NMR (300MHz, DMSO-d6) δ (ppm) 12.44 (s, 1H), 8.70 (d, J = 7.0Hz, 1H), 8.29 (s, 1H), 7.82 (dd, J = 11.7, 7.8Hz, 2H), 7.26 (dd, J = 9.6, 6.8Hz, 2H), 7.08 (t, J = 6.9Hz, 1H), 5.28 (s, 2H), 5.02 (s, 2H), 3.97 (s, 3H). Example 3: Synthesis of methyl 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzo[d]oxazol-4-carboxylic acid (compound 3)

[0091]

[0092] Step 1: Synthesis of intermediate 3-2

[0093] N-Benzyloxycarbonylglycine (1.5 g, 7.18 mmol) was dissolved in 30 mL of DMF, and HATU (2.0 g, 7.77 mmol) and DIPEA (1.6 mL, 8.97 mmol) were added. After stirring for 0.5 h, intermediate 3-1 (1.0 g, 5.98 mmol) was added, and the reaction was carried out at room temperature for 8 h. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and purified by silica gel column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give 1.52 g of the intermediate as a white solid.

[0094] The obtained intermediate (1.0 g) was dissolved in 10 mL of glacial acetic acid and reacted at 65 °C for 1 h. After the reaction was complete, acetic acid was removed by rotary evaporation, diluted with water, extracted with ethyl acetate, and the organic phase was concentrated. The intermediate 3-2 was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 80:1, v / v) to give intermediate 3-2, 816 mg of white solid (two-step yield 70.36%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 12.26 (s, 1H), 7.90 (d, J = 7.3Hz, 2H), 7.82 (dd, J = 7.7, 1.1Hz, 1H) ,7.39(t,J=4.4Hz,5H),7.32(d,J=7.9Hz,1H),5.09(s,2H),4.55(d,J=6.0Hz,2H),3.97(s,3H).

[0095] Step 2: Synthesis of intermediate 3-3

[0096] Intermediate 3-2 (500 mg, 1.47 mmol) was dissolved in 10 mL of ethanol, and Pd / C (200 mg) was added. The mixture was then purged with hydrogen and reacted at room temperature for 4 h. After the reaction was complete as monitored by TLC, Pd / C was removed by diatomaceous earth filtration. The filtrate was concentrated to obtain crude intermediate 3-3, which did not require purification and was reserved for further use.

[0097] Step 3: Synthesis of intermediates 3-4

[0098] Intermediate 3-3 (200 mg, 0.97 mmol) and intermediate m (184.5 mg, 0.97 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (116.4 mg, 0.97 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (73.4 mg, 1.94 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 3-4, 236 mg of white solid (yield 63.97%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.64(d,J=6.9Hz,1H),8.36(s,1H),7.77(d,J=7.7Hz,1H),7.63(d,J=7.5Hz,1H ),7.47(d,J=7.1Hz,1H),7.20(t,J=7.8Hz,1H),7.01(d,J=7.0Hz,1H),4.30(s,2H),4.02(s,2H),3.91(s,3H).

[0099] Step 4: Synthesis of Compound 3

[0100] Intermediate 3-4 (50 mg, 0.131 mmol) was dissolved in 5 mL of DMF, and HATU (61.2 mg, 0.161 mmol) and NMM (17 mg, 0.161 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 3, 23 mg of white solid (yield 48.29%, purity 97.82%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.71(d,J=7.0Hz,1H),8.69(s,1H),7.82(dd,J=11.7,7.8Hz,2H ), 7.26 (dd, J = 9.6, 6.8 Hz, 2H), 7.08 (t, J = 6.9 Hz, 1H), 5.28 (s, 2H), 5.02 (s, 2H), 3.97 (s, 3H).

[0101] Example 4: Synthesis of methyl 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)-1H-indole-7-carboxylic acid (compound 4)

[0102]

[0103] Step 1: Synthesis of intermediate 4-2

[0104] Intermediate 4-1 (900 mg, 3.91 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (606.8 mg, 3.91 mmol), CuI (38.1 mg, 0.20 mmol), and Pd(PPh3)2Cl2 (274.4 mg, 0.391 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 100:1, v / v) to give intermediate 4-2, 860 mg (yield 64.71%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)7.82(dd,J=8.1,1.6Hz,1H),7.49(s,1H),7.47(d,J=1.6Hz, 1H), 6.82 (s, 2H), 6.63 (t, J = 7.7Hz, 1H), 4.09 (d, J = 5.4Hz, 2H), 3.87 (s, 3H), 1.47 (s, 9H).

[0105] Step 2: Synthesis of intermediate 4-3

[0106] Intermediate 4-2 was placed in a round-bottom flask, and 4 ml of dichloromethane and 1 ml of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed by TLC monitoring, the dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added and the rotary evaporation was repeated several times). The pH was adjusted to about 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0°C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 4-3, which did not require purification and was reserved for the next step.

[0107] Step 3: Synthesis of intermediate 4-4

[0108] Intermediate 4-3 (200 mg, 0.98 mmol) and intermediate m (186.4 mg, 0.98 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (117.6 mg, 0.98 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (74.2 mg, 1.96 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 4-4, 203 mg of white solid (yield 54.78%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.78-8.69 (m, 1H), 8.37 (s, 1H), 7.75 (dd, J = 8.1, 1.6Hz, 1H), 7.48 (d, J = 7.1Hz, 1H), 7.40 ( dd,J=7.4,1.7Hz,1H),7.04(t,J=7.0Hz,1H),6.86(s,2H),6.55(t,J=7.7Hz,1H),4.31(s,2H),4.02(s,2H),3.79(s,3H).

[0109] Step 4: Synthesis of Compound 4

[0110] Intermediate 4-4 (50 mg, 0.132 mmol) was dissolved in 5 mL of DMF, and HATU (61.2 mg, 0.161 mmol) and NMM (17 mg, 0.161 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 3, 27 mg, a white solid (yield 56.70%, purity 95.97%). 1H NMR (300MHz, DMSO-d6) δ (ppm) 8.80-8.72 (m, 1H), 8.39 (s, 1H), 7.77 (dd, J = 8.1, 1.6Hz, 1H), 7.51 (d, J = 7.1Hz, 1H), 7.42 ( dd,J=7.4,1.7Hz,1H),7.06(t,J=7.0Hz,1H),6.88(s,2H),6.57(t,J=7.7Hz,1H),4.34(s,2H),3.82(s,2H),3.81(s,3H).

[0111] Example 5: Synthesis of methyl 5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 5)

[0112]

[0113] Step 1: Synthesis of intermediate 5-2

[0114] 5-1 (1 g, 5.9 mmol) was dissolved in 15 mL of DMF, and NaI (1.06 g, 7.6 mmol) and chloramine T (1.61 g, 7.6 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 5-2, 1.53 g of white solid (yield 87.93%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.04 (s, 1H), 7.96 (dd, J = 7.7, 3.2 Hz, 1H), 7.55 (dd, J = 8.6, 3.1 Hz, 1H), 3.88 (s, 3H).

[0115] Step 2: Synthesis of intermediate 5-3

[0116] Intermediate 5-2 (700 mg, 2.37 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (367.8 mg, 2.37 mmol), CuI (23 mg, 0.12 mmol), and Pd(PPh3)2Cl2 (166 mg, 0.237 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 5-3, 430 mg of pale yellow solid (yield 56.12%). 1H NMR (300MHz, DMSO-d6) δ (ppm) 7.76 (dd, J = 8.3, 2.8 Hz, 1H), 7.64-7.59 (m, 2H), 6.78 (s, 1H), 4.34 (d, J = 5.9 Hz, 2H), 3.93 (s, 3H), 1.43 (s, 9H).

[0117] Step 3: Synthesis of intermediate 5-4

[0118] Intermediate 5-3 (400 mg, 1.24 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 5-4, which did not require purification and was reserved for further use.

[0119] Step 4: Synthesis of intermediate 5-5

[0120] Intermediate 5-4 (200 mg, 0.90 mmol) and intermediate m (171 mg, 0.90 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (108 mg, 0.90 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (68.1 mg, 1.8 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 5-5, 198 mg, a white solid (yield 55.36%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.75-8.68 (m, 1H), 8.39 (s, 1H), 7.74 (dd, J = 8.4, 2.8Hz, 1H), 7 .60-7.49(m,2H),7.06(t,J=7.0Hz,1H),6.85(s,1H),4.35(s,2H),3.96(s,2H),3.93(s,3H).

[0121] Step 5: Synthesis of Compound 5

[0122] Intermediate 5-5 (50 mg, 0.126 mmol) was dissolved in 5 mL of DMF, and HATU (57.4 mg, 0.151 mmol) and NMM (15.3 mg, 0.151 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 5, 23 mg of white solid (yield 48.12%, purity 98.15%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.69 (d, J = 7.0 Hz, 1H), 8.32 (s, 1H), 7.73 (dd, J = 8.3, 2.8 Hz, 1H), 7.56 (dd, J = 9.7 ,2.8Hz,1H),7.29(d,J=6.7Hz,1H),7.07(t,J=6.9Hz,1H),6.96(s,1H),5.15(s,2H),4.93(s,2H),3.89(s,3H).

[0123] Example 6: Synthesis of methyl 5-chloro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 6)

[0124]

[0125] Step 1: Synthesis of intermediate 6-2

[0126] 6-1 (1 g, 5.36 mol) was dissolved in 10 mL of DMF, and NaI (1.04 g, 6.97 mol) and chloramine T (1.59 g, 6.97 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 10:1, v / v) to give intermediate 6-2, 1.46 g of white solid (yield 87.16%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.25 (s, 1H), 8.09 (d, J = 2.6Hz, 1H), 7.77 (d, J = 2.6Hz, 1H), 3.94 (s, 3H).

[0127] Step 2: Synthesis of intermediate 6-3

[0128] Intermediate 6-2 (700 mg, 2.24 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (347.6 mg, 2.24 mmol), CuI (21 mg, 0.112 mmol), and Pd(PPh3)2Cl2 (157.2 mg, 0.224 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 6-3, 368 mg of pale yellow solid (yield 48.35%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.00(d,J=2.3Hz,1H),7.75(d,J=2.3Hz,1H),7.60 (t,J=6.0Hz,1H),6.78(s,1H),4.35(d,J=5.9Hz,2H),3.94(s,3H),1.43(s,9H).

[0129] Step 3: Synthesis of intermediate 6-4

[0130] Intermediate 6-3 (350 mg, 1.03 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was completed by TLC monitoring, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 6-4, which did not require purification and was reserved for further use.

[0131] Step 4: Synthesis of intermediate 6-5

[0132] Intermediate 6-4 (200 mg, 0.83 mmol) and intermediate m (157.7 mg, 0.83 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (99.6 mg, 0.83 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (62.8 mg, 1.66 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 6-5, 211 mg of white solid (yield 61.43%). 1HNMR(300MHz,DMSO-d6)δ(ppm)8.77-8.70(m,1H),8.41(s,1H),7.77(dd,J=8.4,2.8Hz,1H),7 .60-7.49(m,2H),7.13(t,J=7.0Hz,1H),6.83(s,1H),4.38(s,2H),3.98(s,2H),3.91(s,3H).

[0133] Step 5: Synthesis of Compound 6

[0134] Intermediate 6-5 (50 mg, 0.121 mmol) was dissolved in 5 mL of DMF, and HATU (59.7 mg, 0.157 mmol) and NMM (15.9 mg, 0.157 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 6, 27 mg, a white solid (yield 56.38%, purity 96.83%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.71 (d, J = 7.0Hz, 1H), 8.34 (s, 1H), 7.98 (d, J = 2.3Hz, 1H), 7.76 (d, J = 2.3H z,1H),7.31(d,J=6.9Hz,1H),7.10(t,J=7.0Hz,1H),6.97(s,1H),5.17(s,2H),4.95(s,2H),3.91(s,3H).

[0135] Example 7: Synthesis of methyl 5-bromo-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 7)

[0136]

[0137] Step 1: Synthesis of intermediate 7-2

[0138] 7-1 (1 g, 4.33 mol) was dissolved in 5 mL of DMF, and NaI (0.84 g, 5.63 mol) and chloramine T (1.28 g, 5.63 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether: ethyl acetate = 100:1, v / v) to give intermediate 7-2, 1.22 g of white solid (yield 78.94%). 1H NMR (300MHz, DMSO-d6) δ (ppm) 11.26 (s, 1H), 8.20 (d, J = 2.5Hz, 1H), 7.89 (d, J = 2.4Hz, 1H), 3.93 (s, 3H).

[0139] Step 2: Synthesis of intermediate 7-3

[0140] Intermediate 7-2 (800 mg, 2.24 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (347.6 mg, 2.24 mmol), CuI (21 mg, 0.112 mmol), and Pd(PPh3)2Cl2 (157.2 mg, 0.224 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 7-3, 412 mg of pale yellow solid (yield 47.87%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.11(d,J=2.1Hz,1H),7.85(d,J=2.2Hz,1H),7.59 (t,J=5.9Hz,1H),6.77(s,1H),4.34(d,J=5.9Hz,2H),3.93(s,3H),1.42(s,9H).

[0141] Step 3: Synthesis of intermediate 7-4

[0142] Intermediate 7-3 (400 mg, 1.04 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 7-4, which did not require purification and was reserved for further use.

[0143] Step 4: Synthesis of intermediate 7-5

[0144] Intermediate 7-4 (200 mg, 0.70 mmol) and intermediate m (133.8 mg, 0.70 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (84 mg, 0.70 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (53.1 mg, 1.4 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 7-5, 236 mg of white solid (yield 73.57%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 9.10 (dd, J=7.1, 1.3Hz, 1H), 8.26 (s, 1H), 8.16 (d, J= 2.0Hz,1H),7.91(t,J=2.2Hz,1H),7.31-7.26(m,1H),7.04(t,J=7.0Hz,1H),6.84(s 1H),4.35(s,2H),3.96(s,2H),3.93(s,3H).

[0145] Step 5: Synthesis of Compound 7

[0146] Intermediate 7-5 (60 mg, 0.131 mmol) was dissolved in 5 mL of DMF, and HATU (59.8 mg, 0.157 mmol) and NMM (15.9 mg, 0.157 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 7, 34 mg, a white solid (yield 58.99%, purity 96.17%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.69(d,J=6.9Hz,1H),8.32(s,1H),8.09(d,J=2.1Hz,1H),7.86(d,J=2.1H z, 1H), 7.29 (d, J = 7.0Hz, 1H), 7.07 (t, J = 6.9Hz, 1H), 6.95 (s, 1H), 5.15 (s, 2H), 4.93 (s, 2H), 3.88 (s, 3H).

[0147] Example 8: Synthesis of methyl 5-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid ester (compound 8)

[0148]

[0149] Step 1: Synthesis of intermediate 8-2

[0150] Dissolve 8-1 (1 g, 6.02 mol) in 10 mL of DMF, add NaI (1.17 g, 7.82 mol) and chloramine T (1.78 g, 7.82 mmol), and react at room temperature for 6 h. After the reaction is complete as monitored by TLC, dilute with water, extract with ethyl acetate, concentrate the organic phase, and separate by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 8-2, 1.19 g white solid (yield 67.68%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.05 (s, 1H), 7.79 (d, J = 2.2Hz, 1H), 7.56-7.48 (m, 1H), 3.84 (s, 3H), 2.15 (s, 3H).

[0151] Step 2: Synthesis of intermediate 8-3

[0152] Intermediate 8-2 (800 mg, 2.74 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (425.2 mg, 2.74 mmol), CuI (26.1 mg, 0.137 mmol), and Pd(PPh3)2Cl2 (192.3 mg, 0.274 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 8-3, 465 mg of white solid (yield 53.14%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)7.65(dd,J=10.9,1.8Hz,2H),7.57(t,J=6.0Hz,1 H), 6.69 (s, 1H), 4.32 (d, J = 5.9Hz, 2H), 3.91 (s, 3H), 2.43 (s, 3H), 1.42 (s, 9H).

[0153] Step 3: Synthesis of intermediate 8-4

[0154] Intermediate 8-3 (400 mg, 1.25 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 8-4, which did not require purification and was reserved for further use.

[0155] Step 4: Synthesis of intermediate 8-5

[0156] Intermediate 8-4 (200 mg, 0.91 mmol) and intermediate m (172.9 mg, 0.91 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (109.2 mg, 0.91 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (69.03 mg, 1.82 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 8-5, 244 mg of white solid (yield 68.16%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.74 (d, J = 6.8 Hz, 1H), 8.40 (s, 1H), 7.71-7.61 (m, 2H), 7.56 (d, J = 7. 0Hz, 1H), 7.07 (t, J = 7.0Hz, 1H), 6.81 (s, 1H), 4.36 (s, 2H), 3.97 (s, 2H), 3.91 (s, 3H), 2.43 (s, 3H).

[0157] Step 5: Synthesis of Compound 8

[0158] Intermediate 8-5 (70 mg, 0.18 mmol) was dissolved in 5 mL of DMF, and HATU (82.13 mg, 0.216 mmol) and NMM (21.8 mg, 0.216 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 8, 41 mg of white solid (yield 60.68%, purity 95.97%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.68 (d, J = 6.9 Hz, 1H), 8.32 (s, 1H), 7.63 (d, J = 3.7 Hz, 2H), 7.28 (d, J = 6.9Hz,1H),7.06(t,J=6.9Hz,1H),6.87(s,1H),5.14(s,2H),4.91(s,2H),3.87(s,3H),2.41(s,3H).

[0159] Example 9: Synthesis of methyl 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthid-4(5H)-yl)methyl)-5-(trifluoromethyl)benzofuran-7-carboxylic acid (compound 9)

[0160]

[0161] Step 1: Synthesis of intermediate 9-2

[0162] 9-1 (1 g, 4.54 mol) was dissolved in 10 mL of DMF, and NaI (0.89 mg, 5.90 mol) and chloramine T (1.34 g, 5.90 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 80:1, v / v) to give intermediate 9-2, 1.10 g of white solid (yield 70.02%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.70 (s, 1H), 8.35 (d, J = 2.3Hz, 1H), 8.06 (d, J = 2.4Hz, 1H), 3.96 (s, 3H).

[0163] Step 2: Synthesis of intermediate 9-3

[0164] Intermediate 9-2 (800 mg, 2.31 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (358.5 mg, 2.31 mmol), CuI (22.1 mg, 0.116 mmol), and Pd(PPh3)2Cl2 (162.1 mg, 0.231 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 80:1, v / v) to give intermediate 9-3, 465 mg of white solid (yield 53.92%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.34 (s, 1H), 8.04 (d, J = 2.0Hz, 1H), 7.61 (s, 1H), 6.92 (s, 1H), 4.37 (d, J = 5.8Hz, 2H), 3.95 (s, 3H), 1.42 (s, 9H).

[0165] Step 3: Synthesis of intermediate 9-4

[0166] Intermediate 9-3 (400 mg, 1.07 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 9-4, which did not require purification and was reserved for further use.

[0167] Step 4: Synthesis of intermediate 9-5

[0168] Intermediate 9-4 (200 mg, 0.73 mmol) and intermediate m (138.7 mg, 0.73 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (87.6 mg, 0.73 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (55.23 mg, 1.46 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 9-5, 226 mg of white solid (yield 69.20%). 1 HNMR(300MHz,Chloroform-d)δ(ppm)8.40-8.28(m,2H),8.19(d,J=1.8Hz,1H),8.00(s ,1H),7.08(d,J=6.6Hz,1H),6.96-6.86(m,2H),5.22(s,2H),5.00(s,2H),4.02(s,3H).

[0169] Step 5: Synthesis of Compound 9

[0170] Intermediate 9-5 (70 mg, 0.16 mmol) was dissolved in 5 mL of DMF, and HATU (73.01 mg, 0.192 mmol) and NMM (19.4 mg, 0.192 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 9, 32 mg of white solid (yield 46.58%, purity 96.35%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.69 (d, J = 6.9Hz, 1H), 8.35-8.28 (m, 2H), 8.04 (s, 1H) ),7.29(d,J=6.9Hz,1H),7.13-7.02(m,2H),5.16(s,2H),4.97(s,2H),3.92(s,3H).

[0171] Example 10: Synthesis of methyl 5-cyano-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 10)

[0172]

[0173] Step 1: Synthesis of intermediate 10-2

[0174] 10⁻¹ (1 g, 5.64 mol) was dissolved in 10 mL of DMF, and NaI (1.10 g, 7.33 mol) and chloramine T (1.67 g, 7.33 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 10⁻², 1.51 g of white solid (yield 87.16%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.05 (s, 1H), 8.08 (d, J = 2.2Hz, 1H), 8.00 (d, J = 2.2Hz, 1H), 3.87 (s, 3H).

[0175] Step 2: Synthesis of intermediate 10-3

[0176] Intermediate 10⁻² (700 mg, 2.31 mmol) was placed in a round-bottom flask, and triethylamine (20 mL), N-Boc-aminopropyne (360.1 mg, 2.31 mmol), CuI (22.1 mg, 0.116 mmol), and Pd(PPh₃)₂Cl₂ (162.1 mg, 0.231 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 10⁻³, 345 mg, a pale yellow solid (yield 45.21%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.43(d,J=1.7Hz,1H),8.16(d,J=1.7Hz,1H),7.62 (t,J=6.0Hz,1H),6.90(s,1H),4.38(d,J=5.9Hz,2H),3.95(s,3H),1.43(s,9H).

[0177] Step 3: Synthesis of intermediate 10⁻⁴

[0178] Intermediate 10⁻³ (320 mg, 0.97 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 10⁻⁴, which did not require purification and was reserved for further use.

[0179] Step 4: Synthesis of intermediate 10-5

[0180] Intermediate 10⁻⁴ (200 mg, 0.87 mmol) and intermediate m (165.3 mg, 0.87 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (104.4 mg, 0.87 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH₄ (66.0 mg, 1.74 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 10⁻⁵, 201 mg, a white solid (yield 57.13%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.92(d,J=6.8Hz,1H),8.66-8.50(m,2H),8.35(d,J=1.8Hz,1H),7 .75(d,J=7.0Hz,1H),7.27(t,J=7.0Hz,1H),7.14(s,1H),4.56(s,2H),4.20(s,2H),4.16(s,3H).

[0181] Step 5: Synthesis of Compound 10

[0182] Intermediate 10⁻⁵ (100 mg, 0.247 mmol) was dissolved in 5 mL of DMF, and HATU (112.9 mg, 0.297 mmol) and NMM (30.04 mg, 0.297 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was completed by TLC monitoring, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give 10.62 mg of the target product compound as a white solid (yield 64.97%, purity 97.72%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.69(d,J=6.9Hz,1H),8.40(d,J=1.8Hz,1H),8.32(s,1H),8.15(d ,J=1.7Hz,1H),7.28(d,J=6.9Hz,1H),7.14-7.01(m,2H),5.16(s,2H),4.96(s,2H),3.90(s,3H).

[0183] Example 11: Synthesis of methyl 5-carbamoyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 11)

[0184]

[0185] Step 1: Synthesis of intermediate 11-2

[0186] 11-1 (1 g, 5.21 mol) was dissolved in 10 mL of DMF, and NaI (1.0 g, 6.66 mol) and chloramine T (1.52 g, 6.66 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 11-2, 1.21 g of white solid (yield 72.33%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.07 (s, 1H), δ 8.04 (d, J = 2.4Hz, 1H), 7.90 (d, J = 2.4Hz, 1H), 3.95 (s, 3H).

[0187] Step 2: Synthesis of intermediate 11-3

[0188] Intermediate 11-2 (700 mg, 2.18 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (338.3 mg, 2.18 mmol), CuI (20.8 mg, 0.109 mmol), and Pd(PPh3)2Cl2 (153.0 mg, 0.218 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 11-3, 322 mg of pale yellow solid (yield 42.40%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.27(d,J=1.9Hz,1H),7.95(d,J=1.9Hz,1H),7.48 (t,J=6.0Hz,1H),6.90(s,1H),4.36(d,J=5.9Hz,2H),3.95(s,3H),1.43(s,9H).

[0189] Step 3: Synthesis of intermediate 11-4

[0190] Intermediate 11-3 (300 mg, 0.86 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 11-4, which did not require purification and was reserved for further use.

[0191] Step 4: Synthesis of intermediate 11-5

[0192] Intermediate 11-4 (200 mg, 0.81 mmol) and intermediate m (153.9 mg, 0.81 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (97.2 mg, 0.81 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (61.4 mg, 1.62 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 11-5, 196 mg of pale yellow solid (yield 57.29%). 1 HNMR(300MHz,DMSO-d6)δ(ppm)8.97(d,J=2.4Hz,1H),8.88(d,J=6.8Hz,1H),8.73(d,J=2.6Hz,1H ), 8.55 (s, 1H), 7.72 (d, J = 7.2Hz, 1H), 7.28-7.16 (m, 2H), 4.54 (s, 2H), 4.18 (s, 2H), 4.10 (s, 3H).

[0193] Step 5: Synthesis of Compound 11

[0194] Intermediate 11-5 (100 mg, 0.237 mmol) was dissolved in 10 mL of DMF, and HATU (108.0 mg, 0.284 mmol) and NMM (28.7 mg, 0.284 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 11, 41 mg, a white solid (yield 42.78%). 1 HNMR(300MHz,DMSO-d6)δ(ppm)8.78(d,J=2.5Hz,1H),8.69(d,J=6.9Hz,1H),8.54(d,J=2.5Hz,1H),8.32(s, 1H), 7.28 (dd, J = 5.2, 3.5Hz, 1H), 7.18 (s, 1H), 7.07 (t, J = 6.9Hz, 1H), 5.17 (s, 2H), 4.98 (s, 2H), 3.94 (s, 3H).

[0195] Example 12: Synthesis of methyl 5-nitro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 12)

[0196]

[0197] Step 1: Synthesis of Intermediate 12-2

[0198] 12-1 (1 g, 5.07 mol) was dissolved in 10 mL of DMF, and NaI (0.91 g, 6.09 mol) and chloramine T (1.39 g, 6.09 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 12-2, 1.14 g of yellow solid (yield 69.60%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.05 (s, 1H), δ 8.08 (d, J = 2.2Hz, 1H), 8.00 (d, J = 2.2Hz, 1H), 3.87 (s, 3H).

[0199] Step 2: Synthesis of intermediate 12-3

[0200] Intermediate 12-2 (700 mg, 2.17 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (336.8 mg, 2.17 mmol), CuI (20.6 mg, 0.108 mmol), and Pd(PPh3)2Cl2 (152.3 mg, 0.217 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 12-3, 298 mg of pale yellow solid (yield 39.20%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.38(d,J=1.7Hz,1H),8.07(d,J=1.7Hz,1H),7.75 (t,J=6.0Hz,1H),6.99(s,1H),4.38(d,J=5.9Hz,2H),3.95(s,3H),1.43(s,9H).

[0201] Step 3: Synthesis of intermediate 12-4

[0202] Intermediate 12-3 (290 mg, 0.83 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 12-4, which did not require purification and was reserved for further use.

[0203] Step 4: Synthesis of intermediate 12-5

[0204] Intermediate 12-4 (200 mg, 0.80 mmol) and intermediate m (152.2 mg, 0.80 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (96 mg, 0.80 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (60.5 mg, 1.60 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 12-5, 206 mg of pale yellow solid (yield 60.68%). 1 HNMR(300MHz,DMSO-d6)δ(ppm)8.97(d,J=2.4Hz,1H),8.88(d,J=6.8Hz,1H),8.73(d,J=2.6Hz,1H ), 8.55 (s, 1H), 7.72 (d, J = 7.2Hz, 1H), 7.28-7.16 (m, 2H), 4.54 (s, 2H), 4.18 (s, 2H), 4.10 (s, 3H).

[0205] Step 5: Synthesis of Compound 12

[0206] Intermediate 12-5 (100 mg, 0.236 mmol) was dissolved in 5 mL of DMF, and HATU (107.7 mg, 0.283 mmol) and NMM (28.6 mg, 0.283 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 12, 49 mg, a pale yellow solid (yield 51.09%, purity 96.35%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.78(d,J=2.5Hz,1H),8.69(d,J=6.9Hz,1H),8.54(d,J=2.5Hz,1H),8.32(s,1 H),7.28(dd,J=5.2,3.5Hz,1H),7.18(s,1H),7.07(t,J=6.9Hz,1H),5.17(s,2H),4.98(s,2H),3.94(s,3H).

[0207] Example 13: Synthesis of methyl 3-chloro-5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 13)

[0208]

[0209] Step 1: Synthesis of Intermediate 13-1

[0210] In a dry, sealed tube, [Ir(OMe)(1,5-cod)]2 (57.84 mg, 0.08 mmol), 4,4'-ditert-butyl-2,2'-bipyridine (41.6 mg, 0.155 mmol), and B2Pin2 (472.3 mg, 1.86 mmol) were added. The reaction was carried out under argon protection. Intermediate 5-3 (500 mg, 1.55 mmol) was dissolved in 4 mL of DME solvent and added to the sealed tube. The tube was then purged with argon, sealed, and reacted at 80 °C for 6 h. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 20:1, v / v) to obtain crude intermediate 13-1. The crude product was directly used for the next step.

[0211] Step 2: Synthesis of intermediate 13-2

[0212] The obtained intermediate 13-1 (572 mg, 1.27 mmol) was dissolved in 10 mL of methanol, and anhydrous CuCl2 (341.5 mg, 2.54 mmol) was added. The mixture was reacted at 50 °C for 8 h. After the reaction was complete, the mixture was filtered through diatomaceous earth, and the filtrate was concentrated and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to obtain intermediate 13-2, 322 mg of white solid. 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.73-7.70 (m, 2H), 7.56 (d, J = 5.9Hz, 1H), 4.40 (d, J = 5.7Hz, 2H), 3.94 (s, 3H), 1.41 (s, 9H).

[0213] Step 3: Synthesis of intermediate 13-3

[0214] Intermediate 13-2 (300 mg, 0.84 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 13-3, which did not require purification and was reserved for further use.

[0215] Step 4: Synthesis of intermediate 13-4

[0216] Intermediate 13-3 (200 mg, 0.78 mmol) and intermediate m (148.2 mg, 0.78 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (93.6 mg, 0.78 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (59.0 mg, 1.56 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 13-4, 188 mg of pale yellow solid (yield 55.82%). 1 HNMR(300MHz,DMSO-d6)δ(ppm)9.10(dd,J=7.1,1.3Hz,1H),8.26(s,1H),7.75(dd,J=8.0,2.1Hz,1H),7.35(d d,J=8.0,2.1Hz,1H),7.31-7.26(m,1H),7.04(dd,J=7.7,7.0Hz,1H),4.14(s,2H),4.03(s,2H),3.86(s,3H).

[0217] Step 5: Synthesis of Compound 13

[0218] Intermediate 13-4 (100 mg, 0.232 mmol) was dissolved in 5 mL of DMF, and HATU (105.7 mg, 0.278 mmol) and NMM (28.1 mg, 0.278 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 13, 52 mg, a white solid (yield 54.17%, purity 98.66%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.68 (d, J = 6.9 Hz, 1H), 8.31 (s, 1H), 7.78 (dd, J = 7.8, 2.7 Hz, 1H), 7.69 (dd, J=9.6,2.7Hz,1H),7.31(d,J=7.0Hz,1H),7.07(t,J=6.9Hz,1H),5.15(s,2H),5.00(s,2H),3.86(s,3H).

[0219] Example 14: Synthesis of methyl 3,5-dichloro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 14)

[0220]

[0221] Step 1: Synthesis of Intermediate 14-1

[0222] In a dry, sealed tube, [Ir(OMe)(1,5-cod)]2 (57.84 mg, 0.08 mmol), 4,4'-ditert-butyl-2,2'-bipyridine (39.5 mg, 0.147 mmol), and B2Pin2 (446.9 mg, 1.76 mmol) were added. The reaction was carried out under argon protection. Intermediate 6-3 (500 mg, 1.47 mmol) was dissolved in 4 mL of DME solvent and added to the sealed tube. The tube was then purged with argon, sealed, and reacted at 80 °C for 6 h. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 20:1, v / v) to obtain crude intermediate 14-1. The crude product was directly used for the next step.

[0223] Step 2: Synthesis of intermediate 14-2

[0224] The obtained intermediate 14-1 (336 mg, 0.72 mmol) was dissolved in 10 mL of methanol, and anhydrous CuCl2 (193.61 mg, 1.44 mmol) was added. The mixture was reacted at 50 °C for 8 h. After the reaction was complete, the mixture was filtered through diatomaceous earth, and the filtrate was concentrated and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to obtain intermediate 14-2, 220 mg of white solid. 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.88 (d, J = 2.2Hz, 1H), 7.70 (d, J = 2.2Hz, 1H), 7.35 (t, J = 4.8Hz, 1H), 4.57 (d, J = 5.6Hz, 2H), 3.86 (s, 3H), 1.42 (s, 9H).

[0225] Step 3: Synthesis of intermediate 14-3

[0226] Intermediate 14-2 (210 mg, 0.56 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 14-3, which did not require purification and was reserved for further use.

[0227] Step 4: Synthesis of intermediate 14-4

[0228] Intermediate 14-3 (200 mg, 0.73 mmol) and intermediate m (138.7 mg, 0.73 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (87.6 mg, 0.73 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (55.2 mg, 1.46 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 14-4, 192 mg of white solid (yield 58.67%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)9.07(dd,J=7.1,1.3Hz,1H),8.23(s,1H),7.88(d,J=2.2Hz,1H),7.70(d ,J=2.2Hz,1H),7.31-7.26(m,1H),7.04(dd,J=7.7,7.0Hz,1H),4.28(s,2H),4.05(s,2H),3.96(s,3H).

[0229] Step 5: Synthesis of Compound 14

[0230] Intermediate 14-4 (100 mg, 0.223 mmol) was dissolved in 5 mL of DMF, and HATU (101.9 mg, 0.268 mmol) and NMM (27.1 mg, 0.268 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 14, 56 mg, a white solid (yield 58.37%, purity 96.64%). 1 ¹H NMR (300MHz, DMSO-d6) δ (ppm) 8.63 (d, J = 6.9Hz, 1H), 8.26 (s, 1H), 7.91 (d, J = 2.2Hz, 1H), 7.80 (d, J = 2.2Hz, 1H), 7.25 (d, J = 7.0Hz, 1H), 7.01 (t, J = 7.0Hz, 1H), 5.09 (s, 2H), 4.95 (s, 2H), 3.81 (s, 3H). Example 15: Synthesis of methyl 3-chloro-5-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 15).

[0231]

[0232] Step 1: Synthesis of Intermediate 15-1

[0233] In a dry, sealed tube, [Ir(OMe)(1,5-cod)]2 (57.84 mg, 0.08 mmol), 4,4'-ditert-butyl-2,2'-bipyridine (42.1 mg, 0.157 mmol), and B2Pin2 (474.4 mg, 1.88 mmol) were added. The reaction was carried out under argon protection. Intermediate 8-3 (500 mg, 1.57 mmol) was dissolved in 4 mL of DME solvent and added to the sealed tube. The tube was then purged with argon, sealed, and reacted at 80 °C for 6 h. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 40:1, v / v) to obtain crude intermediate 15-1. The crude product was directly used for the next step.

[0234] Step 2: Synthesis of Intermediate 15-2

[0235] The obtained intermediate 15-1 (364 mg, 0.82 mmol) was dissolved in 10 mL of methanol, and anhydrous CuCl2 (220.5 mg, 1.64 mmol) was added. The mixture was reacted at 50 °C for 8 h. After the reaction was complete, the mixture was filtered through diatomaceous earth, and the filtrate was concentrated and separated by column chromatography (petroleum ether: ethyl acetate = 60:1, v / v) to obtain intermediate 15-2, 230 mg of white solid. 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.76 (d, J = 1.8 Hz, 1H), 7.65 (s, 1H), 7.56 (t, J = 5.6 Hz, 1H), 4.37 (d, J = 5.6 Hz, 2H), 3.92 (s, 3H), 2.48 (s, 3H), 1.41 (s, 9H).

[0236] Step 3: Synthesis of intermediate 15-3

[0237] Intermediate 15-2 (220 mg, 0.87 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 15-3, which did not require purification and was reserved for further use.

[0238] Step 4: Synthesis of intermediate 15-4

[0239] Intermediate 15-3 (200 mg, 0.79 mmol) and intermediate m (150.1 mg, 0.79 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (94.8 mg, 0.79 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (59.8 mg, 1.58 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 15-4, 211 mg, a white solid (yield 62.43%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.65-8.56 (m, 1H), 8.34 (s, 1H), 7.72 (d, J = 1.9Hz, 1H), 7.55 ( d,J=7.5Hz,2H),7.01(t,J=7.0Hz,1H),4.32(s,2H),3.94(s,2H),3.93(s,3H),2.47(s,3H).

[0240] Step 5: Synthesis of Compound 15

[0241] Intermediate 15-4 (100 mg, 0.234 mmol) was dissolved in 5 mL of DMF, and HATU (106.8 mg, 0.281 mmol) and NMM (28.4 mg, 0.281 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give 15.61 mg of the target product compound as a white solid (yield 63.61%, purity 98.67%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.70(d,J=6.9Hz,1H),8.33(s,1H),7.71(dd,J=27.7,2.0Hz,2H) ,7.36-7.28(m,1H),7.08(t,J=6.9Hz,1H),5.15(s,2H),5.00(s,2H),3.86(s,3H),2.48(s,3H).

[0242] Example 16: Synthesis of methyl 3-chloro-5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 16)

[0243]

[0244] Step 1: Synthesis of Intermediate 16-1

[0245] In a dry, sealed tube, [Ir(OMe)(1,5-cod)]2 (57.84 mg, 0.08 mmol), 4,4'-ditert-butyl-2,2'-bipyridine (41.6 mg, 0.155 mmol), and B2Pin2 (472.3 mg, 1.86 mmol) were added. The reaction was carried out under argon protection. Intermediate 5-3 (500 mg, 1.55 mmol) was dissolved in 4 mL of DME solvent and added to the sealed tube. The tube was then purged with argon, sealed, and reacted at 80°C for 6 h. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 20:1, v / v) to obtain crude intermediate 16-1. The crude product was directly used for the next step.

[0246] Step 2: Synthesis of intermediate 16-2

[0247] The obtained intermediate 16-1 (331 mg, 0.74 mmol) was dissolved in 10 mL of methanol, and anhydrous CuBr2 (330.6 mg, 1.48 mmol) was added. The reaction was carried out at 50 °C for 8 h. After the reaction was complete, the mixture was filtered through diatomaceous earth, and the filtrate was concentrated and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to obtain intermediate 16-2, 230 mg of white solid. 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.76-7.72 (m, 2H), 7.53 (d, J = 5.9Hz, 1H), 4.42 (d, J = 5.7Hz, 2H), 3.93 (s, 3H), 1.43 (s, 9H).

[0248] Step 3: Synthesis of intermediate 16-3

[0249] Intermediate 16-2 (220 mg, 0.73 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 16-3, which did not require purification and was reserved for further use.

[0250] Step 4: Synthesis of intermediate 16-4

[0251] Intermediate 16-3 (200 mg, 0.66 mmol) and intermediate m (125.4 mg, 0.66 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (79.2 mg, 0.66 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (49.9 mg, 1.32 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 16-4, 187 mg of white solid (yield 59.49%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)9.01(dd,J=7.1,1.3Hz,1H),8.15(s,1H),7.77(dd,J=8.0,2.1H z,1H),7.29-7.25(m,2H),7.04(dd,J=7.7,6.9Hz,1H),4.10(s,2H),4.01(s,2H),3.81(s,3H).

[0252] Step 5: Synthesis of Compound 16

[0253] Intermediate 16-4 (100 mg, 0.21 mmol) was dissolved in 5 mL of DMF, and HATU (95.8 mg, 0.252 mmol) and NMM (25.5 mg, 0.252 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 16, 44 mg, a white solid (yield 45.72%, purity 96.79%). 1 HNMR(300MHz,DMSO-d6)δ(ppm)8.69(d,J=7.0Hz,1H),8.32(s,1H),7.70(t,J=2.2Hz,1H),7.6 7(s,1H),7.31(d,J=6.9Hz,1H),7.07(t,J=6.9Hz,1H),5.15(s,2H),4.99(s,2H),3.85(s,3H).

[0254] Example 17: Synthesis of methyl 4,5-difluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 17)

[0255]

[0256] Step 1: Synthesis of intermediate 17-2

[0257] 17-1 (1 g, 5.3 mmol) was dissolved in 10 mL of DMF, and NaI (0.96 g, 6.4 mmol) and chloramine T (1.46 g, 6.4 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 17-2, 1.42 g of white solid (yield 85.32%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.40 (s, 1H), 7.87 (dd, J = 10.6, 9.1Hz, 1H), 3.93 (s, 3H).

[0258] Step 2: Synthesis of intermediate 17-3

[0259] Intermediate 17-2 (700 mg, 2.23 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (346.1 mg, 2.23 mmol), CuI (21 mg, 0.11 mmol), and Pd(PPh3)2Cl2 (156.5 mg, 0.223 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 17-3, 422 mg of pale yellow solid (yield 55.44%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.84 (dd, J = 11.4, 7.8Hz, 1H), 7.61 (s, 1H), 6.95 (s, 1H), 4.34 (d, J = 5.7Hz, 2H), 3.91 (s, 3H), 1.41 (s, 9H).

[0260] Step 3: Synthesis of intermediate 17-4

[0261] Intermediate 17-3 (400 mg, 1.17 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 17-4, which did not require purification and was reserved for further use.

[0262] Step 4: Synthesis of intermediate 17-5

[0263] Intermediate 17-4 (200 mg, 0.83 mmol) and intermediate m (157.7 mg, 0.83 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (199.2 mg, 1.66 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (62.8 mg, 1.66 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 17-5, 179 mg, a white solid (yield 51.92%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.75(d,J=6.8Hz,1H),8.41(s,1H),7.86(dd,J=11.4,7.8Hz,1H),7 .59(d,J=7.1Hz,1H),7.10(t,J=7.0Hz,1H),7.02(s,1H),4.40(s,2H),4.00(s,2H),3.97(s,3H).

[0264] Step 5: Synthesis of Compound 17

[0265] Intermediate 17-4 (100 mg, 0.241 mmol) was dissolved in 5 mL of DMF, and HATU (109.9 mg, 0.289 mmol) and NMM (29.2 mg, 0.289 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was monitored by TLC until it was complete, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give 17,58 mg of the target product compound as a white solid (yield 60.57%, purity 95.48%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.73(d,J=6.9Hz,1H),8.36(s,1H),7.86(dd,J=11.4,7.8Hz,1H),7 .33(d,J=7.0Hz,1H),7.25(s,1H),7.12(t,J=6.9Hz,1H),5.21(s,2H),4.98(s,2H),3.93(s,3H).

[0266] Example 18: Synthesis of methyl 4-bromo-5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 18)

[0267]

[0268] Step 1: Synthesis of intermediate 18-2

[0269] 18-1 (1 g, 4.0 mmol) was dissolved in 10 mL of DMF, and NaI (0.72 g, 4.8 mmol) and chloramine T (1.09 g, 4.8 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 18-2, 1.09 g of white solid (yield 72.68%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.42 (s, 1H), 7.78 (d, J = 8.7Hz, 1H), 3.95 (s, 3H).

[0270] Step 2: Synthesis of intermediate 18-3

[0271] Intermediate 18-2 (700 mg, 1.87 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (347.6 mg, 2.24 mmol), CuI (21 mg, 0.112 mmol), and Pd(PPh3)2Cl2 (157.2 mg, 0.224 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 60:1, v / v) to give intermediate 18-3, 322 mg of pale yellow solid (yield 42.81%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)7.73(d,J=9.6Hz,1H),7.27-7.19(m,1H),6.94 -6.85(m,1H),6.79(s,1H),4.37(d,J=5.8Hz,2H),3.94(s,3H),1.43(s,9H).

[0272] Step 3: Synthesis of intermediate 18-4

[0273] Intermediate 18-3 (310 mg, 0.77 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 18-4, which did not require purification and was reserved for further use.

[0274] Step 4: Synthesis of intermediate 18-5

[0275] Intermediate 18-4 (200 mg, 0.66 mmol) and intermediate m (125.4 mg, 0.66 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (79.2 mg, 0.66 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (49.9 mg, 1.32 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 18-5, 159 mg, a white solid (yield 50.58%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.60(dd,J=6.8,1.1Hz,1H),8.26(s,1H),7.59(d,J=9.6Hz,1H),7 .45(d,J=6.9Hz,1H),6.96(t,J=7.0Hz,1H),6.69(s,1H),4.27(s,2H),3.87(s,2H),3.84(s,3H).

[0276] Step 5: Synthesis of Compound 18

[0277] Intermediate 18-4 (100 mg, 0.218 mmol) was dissolved in 5 mL of DMF, and HATU (99.6 mg, 0.262 mmol) and NMM (26.5 mg, 0.262 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was completed by TLC monitoring, the product was separated by column chromatography (dichloromethane:methanol = 60:1, v / v) to give the target product compound 18, 46 mg, a white solid (yield 46.05%, purity 97.62%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.69(d,J=6.9Hz,1H),8.32(s,1H),7.70(d,J=9.6Hz,1H),7.29 (d,J=6.9Hz,1H),7.08(d,J=6.9Hz,1H),7.03(s,1H),5.16(s,2H),4.94(s,2H),3.89(s,3H).

[0278] Example 19: Synthesis of methyl 5-fluoro-4-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 19)

[0279]

[0280] Step 1: Synthesis of intermediate 19-2

[0281] 19-1 (1 g, 5.43 mmol) was dissolved in 10 mL of DMF, and NaI (0.98 g, 6.52 mmol) and chloramine T (1.48 g, 6.52 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 19-2, 1.31 g of white solid (yield 77.81%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.27 (s, 1H), 7.60 (d, J = 9.7Hz, 1H), 3.94 (s, 3H), 2.41 (d, J = 2.5Hz, 3H).

[0282] Step 2: Synthesis of intermediate 19-3

[0283] Intermediate 19-2 (700 mg, 2.26 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (420.6 mg, 2.71 mmol), CuI (26 mg, 0.136 mmol), and Pd(PPh3)2Cl2 (190.2 mg, 0.271 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 19-3, 362 mg of pale yellow solid (yield 47.48%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.91 (s, 1H), 7.60 (t, J = 6.0Hz, 1H), 6.91 (s, 1H), 4.33 (d, J = 5.8Hz, 2H), 3.93 (s, 3H), 2.45 (s, 3H), 1.43 (s, 9H).

[0284] Step 3: Synthesis of intermediate 19-4

[0285] Intermediate 19-3 (350 mg, 1.04 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 19-4, which did not require purification and was reserved for further use.

[0286] Step 4: Synthesis of intermediate 19-5

[0287] Intermediate 19-4 (200 mg, 0.84 mmol) and intermediate m (159.6 mg, 0.84 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (100.8 mg, 0.84 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (62.0 mg, 1.64 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 19-5, 171 mg of white solid (yield 51.75%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.73 (d, J = 5.9Hz, 1H), 8.37 (s, 1H), 8.14 (s, 1H), 7.60-7.48 (m, 2H), 7.07(t,J=7.0Hz,1H),6.93(s,1H),4.38(s,2H),3.98(s,2H),3.90(s,3H),2.41(d,J=1.8Hz,3H).

[0288] Step 5: Synthesis of Compound 19

[0289] Intermediate 19-5 (100 mg, 0.243 mmol) was dissolved in 5 mL of DMF, and HATU (111.0 mg, 0.292 mmol) and NMM (29.5 mg, 0.292 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was completed by TLC monitoring, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give the target product compound 19, 49 mg, a white solid (yield 51.26%, purity 97.16%). 1 H NMR(300MHz,Chloroform-d)δ(ppm)8.38-8.27(m,2H),7.59(d,J=10.3Hz,1H),7.07(d,J=6.9H z,1H),6.90(t,J=6.9Hz,1H),6.79(s,1H),5.21(s,2H),4.95(s,2H),3.97(s,3H),2.41(s,3H).

[0290] Example 20: Synthesis of methyl 4,5-dimethyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 20)

[0291]

[0292] Step 1: Synthesis of intermediate 20-2

[0293] 20-1 (1 g, 5.55 mmol) was dissolved in 10 mL of DMF, and NaI (0.99 g, 6.66 mmol) and chloramine T (1.52 g, 6.66 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 20-2, 1.41 g of white solid (yield 83.0%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.35 (s, 1H), 7.58 (s, 1H), 3.92 (s, 3H), 2.44 (s, 3H), 2.29 (s, 3H).

[0294] Step 2: Synthesis of intermediate 20-3

[0295] Intermediate 20-2 (700 mg, 2.29 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (355.4 mg, 2.29 mmol), CuI (22 mg, 0.114 mmol), and Pd(PPh3)2Cl2 (160.7 mg, 0.229 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 20-3, 360 mg of pale yellow solid (yield 47.15%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 10.84 (s, 1H), 7.57 (s, 1H), 4.02 (d, J = 5.8Hz, 2H), 3.90 (s, 3H), 2.35 (s, 3H), 2.19 (s, 3H), 1.40 (s, 9H).

[0296] Step 3: Synthesis of intermediate 20-4

[0297] Intermediate 20-3 (350 mg, 1.05 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 20-4, which did not require purification and was reserved for further use.

[0298] Step 4: Synthesis of intermediate 20-5

[0299] Intermediate 20-4 (200 mg, 0.86 mmol) and intermediate m (163.4 mg, 0.86 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (103.2 mg, 0.86 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (65.1 mg, 1.72 mmol) was added in an ice bath (0 °C), and the reaction was continued for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 20-5, 192 mg of white solid (yield 54.80%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.76(dd,J=6.9,1.1Hz,1H),8.40(s,1H),8.15(s,1H),7.63(s,1H),7.57(dd,J=7.1 ,1.1Hz,1H),7.08(t,J=7.0Hz,1H),6.92(s,1H),4.40(s,2H),4.01(s,2H),3.88(s,3H),2.40(s,3H),2.33(s,3H).

[0300] Step 5: Synthesis of Compound 20

[0301] Intermediate 20-5 (100 mg, 0.245 mmol) was dissolved in 5 mL of DMF, and HATU (111.8 mg, 0.294 mmol) and NMM (29.7 mg, 0.294 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was completed by TLC monitoring, the product was separated by column chromatography (dichloromethane:methanol = 80:1, v / v) to give 20, 62 mg of the target product compound as a white solid (yield 64.99%, purity 98.34%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.68 (d, J = 7.0 Hz, 1H), 8.31 (s, 1H), 7.62 (s, 1H), 7.28 (d, J = 6.9 Hz,1H),7.12-6.99(m,2H),5.15(s,2H),4.90(s,2H),3.85(s,3H),2.40(s,3H),2.32(s,3H).

[0302] Example 21: Synthesis of methyl 5-bromo-4-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 21)

[0303]

[0304] Step 1: Synthesis of intermediate 21-2

[0305] 21-1 (1 g, 4.08 mmol) was dissolved in 10 mL of DMF, and NaI (0.73 g, 4.90 mmol) and chloramine T (1.11 g, 4.90 mmol) were added. The reaction was carried out at room temperature for 6 h. After the reaction was completed by TLC monitoring, the mixture was diluted with water, extracted with ethyl acetate, and the organic phase was concentrated and separated by column chromatography (petroleum ether:ethyl acetate = 100:1, v / v) to give intermediate 21-2, 1.29 g of pale yellow solid (yield 85.23%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 11.42 (s, 1H), 7.97 (s, 1H), 3.93 (s, 3H), 2.67 (s, 3H).

[0306] Step 2: Synthesis of intermediate 21-3

[0307] Intermediate 21-2 (700 mg, 1.89 mmol) was placed in a round-bottom flask, and triethylamine (20 ml), N-Boc-aminopropyne (293.3 mg, 1.89 mmol), CuI (18 mg, 0.095 mmol), and Pd(PPh3)2Cl2 (132.7 mg, 0.189 mmol) were added. The reaction was carried out under nitrogen protection and heated to 85 °C for 3 h. The reaction was monitored by TLC until complete. After cooling to room temperature, the mixture was filtered through diatomaceous earth. The filtrate was concentrated under vacuum and separated by column chromatography (petroleum ether: ethyl acetate = 40:1, v / v) to give intermediate 21-3, 396 mg of pale yellow solid (yield 52.61%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 7.91 (s, 1H), 7.55 (t, J = 6.0Hz, 1H), 6.91 (s, 1H), 4.33 (d, J = 5.9Hz, 2H), 3.90 (s, 3H), 2.55 (s, 3H), 1.41 (s, 9H).

[0308] Step 3: Synthesis of intermediate 21-4

[0309] Intermediate 21-3 (380 mg, 0.95 mmol) was placed in a round-bottom flask, and 4 mL of dichloromethane and 1 mL of trifluoroacetic acid were added. The mixture was stirred at room temperature for 1 h. After the reaction was complete as monitored by TLC, dichloromethane and trifluoroacetic acid were removed by rotary evaporation (dichloromethane was added repeatedly for rotary evaporation). The pH was adjusted to 8 by adding saturated sodium bicarbonate aqueous solution under ice bath (0 °C). After extraction with ethyl acetate, the organic phase was concentrated to obtain crude intermediate 21-4, which did not require purification and was reserved for further use.

[0310] Step 4: Synthesis of intermediate 21-5

[0311] Intermediate 21-4 (200 mg, 0.67 mmol) and intermediate m (127.3 mg, 0.67 mmol) were dissolved in anhydrous dichloromethane / anhydrous methanol (5 mL: 5 mL), and anhydrous magnesium sulfate (80.4 mg, 0.67 mmol) was added. The mixture was stirred for 6 h under nitrogen protection. NaBH4 (50.7 mg, 1.34 mmol) was added in an ice bath (0 °C), and the reaction was allowed to proceed for 2 h. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated and separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give intermediate 21-5, 186 mg of white solid (yield 58.78%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.71(dd,J=6.9,1.1Hz,1H),8.36(s,1H),7.89(s,1H),7.54(d,J=7.0Hz,1 H), 7.05 (t, J = 7.0Hz, 1H), 6.93 (s, 1H), 5.77 (s, 1H), 4.34 (s, 2H), 3.94 (s, 2H), 3.90 (s, 3H), 2.52 (s, 3H).

[0312] Step 5: Synthesis of Compound 21

[0313] Intermediate 21-5 (100 mg, 0.212 mmol) was dissolved in 5 mL of DMF, and HATU (96.6 mg, 0.254 mmol) and NMM (25.7 mg, 0.254 mmol) were added. The reaction was carried out at room temperature for 4 h. After the reaction was completed by TLC monitoring, the product was separated by column chromatography (dichloromethane:methanol = 20:1, v / v) to give the target product compound 21, 52 mg of white solid (yield 53.99%, purity 97.61%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.68(d,J=6.9Hz,1H),8.31(s,1H),7.90(s,1H),7.28(d,J=6.9H z,1H),7.16(s,1H),7.07(t,J=6.9Hz,1H),5.16(s,2H),4.93(s,2H),3.87(s,3H),2.53(s,3H).

[0314] Example 22: Synthesis of 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 22)

[0315]

[0316] Compound 1 (30 mg, 0.083 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (13.93 mg, 0.33 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 22, yielding 25 mg of a white solid powder (yield 86.70%, purity 95.93%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 13.14 (s, 1H), 8.68 (d, J = 6.9Hz, 1H), 8.31 (s, 1H), 7.81-7.7 6(m,2H),7.36-7.23(m,2H),7.06(t,J=6.9Hz,1H),6.94(s,1H),5.13(s,2H),4.93(s,2H).

[0317] Example 23: Synthesis of 5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 23)

[0318]

[0319] Compound 5 (30 mg, 0.079 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (13.27 mg, 0.32 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 23, yielding 24 mg of a white solid powder (yield 83.07%, purity 98.36%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)13.48(s,1H),8.69(d,J=6.9Hz,1H),8.32(s,1H),7.69(dd,J=8.3,2.9Hz,1H),7. 53(dd,J=9.8,2.8Hz,1H),7.27(d,J=6.7Hz,1H),7.07(t,J=6.9Hz,1H),6.94(s,1H),5.13(s,2H),4.93(s,2H).

[0320] Example 24: Synthesis of 5-chloro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 24)

[0321]

[0322] Compound 6 (30 mg, 0.076 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.72 mg, 0.30 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 24, yielding 26 mg of a white solid powder (yield 89.85%, purity 96.19%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.68(d,J=6.9Hz,1H),8.31(s,1H),7.92(d,J=2.4Hz,1H),7.71(d,J =2.3Hz, 1H), 7.26 (d, J = 7.0Hz, 1H), 7.06 (t, J = 6.9Hz, 1H), 6.93 (s, 1H), 5.12 (s, 2H), 4.93 (s, 2H).

[0323] Example 25: Synthesis of 5-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 25)

[0324]

[0325] Compound 8 (30 mg, 0.080 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (13.27 mg, 0.32 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 25, yielding 26 mg of a white solid powder (yield 90.03%, purity 97.91%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 13.02 (s, 1H), 8.67 (d, J = 7.0Hz, 1H), 8.30 (s, 1H), 7.61 (s, 2H), 7. 26(d,J=6.9Hz,1H),7.06(t,J=6.9Hz,1H),6.85(s,1H),5.11(s,2H),4.90(s,2H),2.40(s,3H).

[0326] Example 26: Synthesis of 2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthid-4(5H)-yl)methyl)-5-(trifluoromethyl)benzofuran-7-carboxylic acid (compound 26)

[0327]

[0328] Compound 9 (30 mg, 0.070 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (11.73 mg, 0.28 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 26, yielding 26 mg of a white solid powder (yield 89.59%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.68(d,J=6.9Hz,1H),8.32(s,1H),8.27(s,1H),8 .02(s,1H),7.26(d,J=7.0Hz,1H),7.12-7.01(m,2H),5.13(s,2H),4.97(s,2H).

[0329] Example 27: Synthesis of 5-cyano-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 27)

[0330]

[0331] Compound 10 (30 mg, 0.078 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (13.03 mg, 0.31 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 27, yielding 24 mg of a white solid powder (yield 83.01%, purity 96.17%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.68(d,J=6.9Hz,1H),8.37(d,J=1.8Hz,1H),8.31(s,1H),8 .11(d,J=1.9Hz,1H),7.26(d,J=6.9Hz,1H),7.12-7.02(m,2H),5.13(s,2H),4.96(s,2H).

[0332] Example 28: Synthesis of 5-carbamoyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 28)

[0333]

[0334] Compound 11 (30 mg, 0.074 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.45 mg, 0.30 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 28, yielding 25 mg of a white solid powder (yield 86.33%, purity 97.85%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.68 (d, J = 6.9 Hz, 1H), 8.38-8.28 (m, 4H), 8.13 (d, J = 9.2H z,1H),7.41(s,1H),7.26(d,J=7.0Hz,1H),7.12-7.01(m,2H),5.13(s,2H),4.95(s,2H).

[0335] Example 29: Synthesis of 3-chloro-5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 29)

[0336]

[0337] Compound 13 (30 mg, 0.073 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.17 mg, 0.29 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 29, yielding 27 mg of a white solid powder (yield 93.16%, purity 95.62%). 1H NMR(300MHz,DMSO-d6)δ(ppm)13.48(s,1H),8.68(d,J=6.9Hz,1H),8.32(s,1H),7.70(dd,J=8.3,2.9Hz, 1H), 7.56 (dd, J=9.8, 2.8Hz, 1H), 7.28 (d, J=6.7Hz, 1H), 7.09 (t, J=6.9Hz, 1H), 5.13 (s, 2H), 4.93 (s, 2H).

[0338] Example 30: Synthesis of 4,5-difluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 30)

[0339]

[0340] Compound 17 (30 mg, 0.076 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.67 mg, 0.30 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 30, yielding 26 mg of a white solid powder (yield 89.84%, purity 97.19%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.68(d,J=6.9Hz,1H),8.31(s,1H),7.77(dd,J=11.5,7.9Hz ,1H),7.26(d,J=6.8Hz,1H),7.18(s,1H),7.07(t,J=6.9Hz,1H),5.14(s,2H),4.94(s,2H).

[0341] Example 31: Synthesis of 4-bromo-5-fluoro-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 31)

[0342]

[0343] Compound 18 (30 mg, 0.065 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (10.99 mg, 0.26 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 31, yielding 28 mg of a white solid powder (yield 96.28%, purity 95.38%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.67(d,J=6.9Hz,1H),8.30(s,1H),7.61(d,J=9.7Hz,1H ), 7.26 (d, J = 7.0Hz, 1H), 7.06 (t, J = 6.9Hz, 1H), 6.95 (s, 1H), 5.14 (s, 2H), 4.93 (s, 2H).

[0344] Example 32: Synthesis of 3-chloro-5-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 32)

[0345]

[0346] Compound 15 (30 mg, 0.073 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.29 mg, 0.29 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Then, dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5. A solid precipitated out, which was then filtered. The filter cake was washed three times with water and dried to obtain compound 32, yielding 27 mg of a white solid powder (yield 93.19%, purity 97.49%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.68(d,J=7.0Hz,1H),8.31(s,1H),7.73(s,1H),7.62(s,1 H), 7.27 (d, J = 6.9 Hz, 1H), 7.06 (t, J = 6.9 Hz, 1H), 5.10 (s, 2H), 4.99 (s, 2H), 2.46 (s, 3H).

[0347] Example 33: Synthesis of 5-fluoro-4-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 33)

[0348]

[0349] Compound 19 (30 mg, 0.076 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.80 mg, 0.31 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 33, yielding 26 mg of a white solid powder (yield 89.87%, purity 97.67%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.69(d,J=6.9Hz,1H),8.32(s,1H),7.50(dd,J=9.4,3.9Hz,1H ),7.27(d,J=7.0Hz,1H),7.13-7.02(m,2H),5.14(s,2H),4.92(s,2H),2.41(d,J=1.8Hz,3H).

[0350] Example 34: Synthesis of 4,5-dimethyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 34)

[0351]

[0352] Compound 20 (30 mg, 0.077 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (12.93 mg, 0.31 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 34, yielding 27 mg of a white solid powder (yield 93.36%, purity 95.97%). 1 H NMR(300MHz,DMSO-d6)δ(ppm)8.69(d,J=6.9Hz,1H),8.31(s,1H),7.60(s,1H),7.26(d,J=7.0Hz,1 H),7.12-6.97(m,2H),5.12(s,2H),4.90(s,2H),3.86(d,J=2.9Hz,1H),2.39(s,3H),2.32(s,3H).

[0353] Example 35: Synthesis of 5-bromo-4-methyl-2-((3-oxo-3H-pyrazolo[4,5,1-ij][1,6]naphthidium-4(5H)-yl)methyl)benzofuran-7-carboxylic acid (compound 35)

[0354]

[0355] Compound 21 (30 mg, 0.066 mmol) was added to a round-bottom flask, followed by 2 ml each of methanol, tetrahydrofuran, and water. Lithium hydroxide monohydrate (11.08 mg, 0.26 mmol) was then added, and the mixture was reacted at 60 °C for 1 h. After the reaction was complete as monitored by TLC, some of the solvent was removed by rotary evaporation. Dilute hydrochloric acid (2N) was slowly added dropwise to adjust the pH to approximately 5, causing a solid to precipitate. The solid was then filtered, and the filter cake was washed three times with water. The filter cake was dried to obtain compound 35, yielding 28 mg of a white solid powder (yield 96.31%, purity 97.41%). 1 H NMR (300MHz, DMSO-d6) δ (ppm) 8.69 (d, J = 6.8 Hz, 1H), 8.31 (s, 1H), 7.89 (s, 1H), 7.27 (d, J =6.9Hz,1H),7.14(s,1H),7.08(d,J=8.4Hz,1H),5.13(s,2H),4.93(s,2H),2.59(s,3H).

[0356] Example 36: Based on THP1-Dual TM Cellular assays to determine the agonistic activity of compounds on the STING signaling pathway

[0357] Stand the T25 cell culture flask upright and gently shake for a few seconds to mix the cells. Use a pipette to transfer the cell suspension to a 15mL centrifuge tube and centrifuge at 1000rpm for 5 minutes to allow the cells to settle to the bottom of the tube. Add a solution containing penicillin, streptomycin, and normocin. TM Resuspend the cells in 10% FBS 1640 medium and dilute them in centrifuge tubes to 100 μL / well, 4 × 10⁻⁶ cells / well. 6 Cells were seeded into 96-well clear cell culture plates. 100 μL of serially diluted assay solution of the target compound was added per well, and the plates were incubated at 37°C for 24 h. Then, 10 μL of cell supernatant was transferred from each well to a new 96-well cell culture plate, and 90 μL of QUANTI-Blue was added in the dark. TMThe solution (Invivogen: rep-qbs, rep-qbs2) was incubated at 37°C for 3 hours. SEAP levels were measured using an ELISA reader at 620 nm to assess NFκB induction and activation. Additionally, 20 μL of cell supernatant was aspirated from each well into a white 96-well cell culture plate, and 50 μL of QUANTI-Luc was added in the dark. TM Solutions (Invivogen: rep-qlc1, rep-qlc2) were immediately analyzed using a spectrophotometer to determine the level of Lucia luciferase, thereby assessing IRF3 induction expression. The half-maximal effect concentration (EC50) was then measured. 50 The results were calculated using the log (agonist) vs. response-variable slope fitting method in Graphpad Prism software.

[0358] The compound reported by BMS was used as a positive control. Test EC 50 The experimental results are shown in Table 1:

[0359] Table 1 EC 50 Experimental results

[0360]

[0361]

[0362] STING protein is a membrane protein located on the endoplasmic reticulum membrane of cells. Compounds 22, 23, 24, 26, 27, 28, 29, 30, 33, 34, and 35 are EC. 50 The value greater than 50 μM is due to the high polarity of the compound, which prevents it from penetrating the cell membrane. Cherney et al. of Bristol-Myers Squibb have experimentally demonstrated that ester molecules in this class of STING agonists enter the cell as prodrugs and hydrolyze into acids within the cell to exert their effects (J. Med. Chem. 2022, 65, 4, 3518–3538). Compounds 22, 23, 24, 27, 28, 29, 30, 33, 34, and 35, and their corresponding ester compounds 1, 5, 6, 10, 11, 13, 17, 19, 20, and 21, all exhibit strong STING agonist activity in the THP1-Dual cell line. Furthermore, Example 37 demonstrates that representative compounds 22 and 29 can directly interact with wild-type STING protein. Therefore, the ester molecules involved in this invention all function as prodrugs, and the acid molecules can directly bind to STING protein.

[0363] Example 37: Thermal Shift Experiment (TSA)

[0364] Experimental Principle and Purpose: Proteins typically exist in their native state. Heating causes proteins to transform into a denatured state, exposing hydrophobic groups. These exposed hydrophobic groups can bind to fluorescent dyes, thereby increasing the emission of the dyes. The stability of the protein is reflected by detecting the fluorescence intensity. When a ligand binds to a protein, the protein's stability increases, resulting in fewer exposed hydrophobic groups at the same temperature. Higher temperatures are required to fully expose these hydrophobic groups, causing a rightward shift in the fluorescence-temperature curve. Therefore, this experiment can directly reflect whether a protein binds to a small molecule ligand.

[0365] Experimental Protocol: This experiment used PCR in 96-well plates, with a final volume of 20 μL per well. 100-400 μM serially diluted compounds (final DMSO concentration 1-2%) or 5 μM cGAMP were incubated with 5 μM recombinant STING protein and 1×SYPRO orange dye in Tris buffer (100 mM Tris, 150 mM NaCl, pH 7.4) for 30 min. Fluorescence signals were measured using a QuantStudio 12K Flex real-time PCR system at a temperature increase rate of 1 °C / min from 25 °C to 95 °C. The melting temperatures (T0) of the unbound and ligand-bound recombinant STING protein were calculated based on the fluorescence derivative curves generated by ThermoFisher Protein Thermal Shift Software 1.3. m ) and the difference in thermal conductivity between the two (ΔT) m ).

[0366]

[0367] Experimental results are as follows Figure 1 As shown.

[0368] The results showed that the selected positive control compound (positive-2) and the preferred compounds 22 and 29 were both related to STING. WT (Wild-type STING) proteins have varying degrees of binding activity.

[0369] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A tricyclic compound of general formula I or a pharmaceutically acceptable salt or racemate thereof: General formula I, where, R1, R2, R3, and R4 are each independently selected from hydrogen, halogen, hydroxyl, C1-C3 haloalkanes, cyano, nitro, formyl, carbamoyl, C1-C3 alkyl, or C1-C3 alkoxy; R5 is selected from hydrogen or C1-C3 alkyl; X1 is selected from O; and X2 is selected from C.

2. The compound according to claim 1, characterized in that, R1 is selected from hydrogen; R2 is selected from hydrogen, halogen, nitro, cyano, C1-C3 alkyl, carbamoyl or trifluoromethyl; R3 is selected from hydrogen, halogen or C1-C3 alkyl; R4 is selected from hydrogen or halogen; R5 is selected from hydrogen or C1-C3 alkyl; X1 is selected from O; X2 is selected from C.

3. The compound according to claim 1, characterized in that, The pharmaceutically acceptable salts include acid addition salts formed by compounds of general formula I with the following acids: hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, acetic acid, citric acid, fumaric acid, tartaric acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, lactic acid, pyruvic acid, maleic acid or succinic acid, salicylic acid, phenylacetic acid, malic acid, and mandelic acid; and also include acid salts formed by compounds of general formula I with inorganic bases.

4. The compound according to claim 3, characterized in that: The pharmaceutically acceptable salts include basic metal cation salts, alkaline earth metal cation salts, and ammonium cation salts.

5. The compound according to claim 1, characterized in that... Selected from: One or more of them.

6. A pharmaceutical composition, characterized in that, This includes the compound according to any one of claims 1-5, or a pharmaceutically acceptable salt or racemic mixture thereof, and a pharmaceutically acceptable carrier.

7. Use of the compound according to any one of claims 1-5 in the preparation of a medicament for treating diseases related to the function of the STING protein.

8. The use according to claim 7, characterized in that, The diseases associated with STING protein function are one or more of the following: inflammation, autoimmune diseases, infectious diseases, or tumors.

9. The use according to claim 8, characterized in that, The tumor-related diseases are selected from colon cancer, stomach cancer, breast cancer, fibrosarcoma, squamous cell carcinoma, lung cancer, melanoma, brain cancer, spinal cancer, liver cancer, cervical cancer, head and neck cancer, leukemia, skin cancer, reproductive system cancer, malignant mesothelioma, sarcoma, lymphoma, adenocarcinoma, thyroid cancer, cardiac tumors, bile duct cancer, kidney cancer, bladder cancer, or bone cancer.

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