PCSK9 inhibitor and application thereof

Abstract

The invention belongs to the field of medicines, and relates to a PCSK9 inhibitor and application thereof, and application of the compound in preparation of medicines for treating or preventing PCSK9-mediated diseases, in particular to a compound shown as a formula I, or a stereoisomer or pharmaceutically acceptable salt or prodrug thereof, and substituent groups in the formula I are as defined in the specification.

Description

[0001] This invention claims priority to the earlier application filed with the China National Intellectual Property Administration on November 12, 2024, with patent application number 202411606429.5 and entitled "A PCSK9 Inhibitor and Its Use Thereof"; and to the earlier application filed with the China National Intellectual Property Administration on January 24, 2025, with patent application number 202510121938.7 and entitled "A PCSK9 Inhibitor and Its Use Thereof". The entire contents of the aforementioned earlier applications are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of medicine, specifically relating to a PCSK9 inhibitor and its use, as well as the use of such compounds in the preparation of medicaments for treating or preventing PCSK9-mediated diseases. Background Technology

[0003] Epidemiological, genetic, and clinical intervention studies have provided ample evidence that LDL-C is a pathogenic risk factor for ASCVD, and reducing LDL-C levels can significantly reduce the incidence and mortality risk of ASCVD.

[0004] The core strategy of lipid management is to implement interventions of varying intensities based on ASCVD risk stratification, while overall ASCVD risk assessment forms the basis for lipid management decisions. LDL-C is the primary target for lipid-lowering therapy; the greater the reduction in LDL-C and the longer the duration of reduction, the greater the decrease in ASCVD risk.

[0005] Although statins can lower serum LDL-C levels and are currently the main lipid-lowering drugs in clinical practice, their lipid-lowering ability is limited (LDL-C reduction <50%), and they have a dose-response bottleneck (doubling the dose only increases the lipid-lowering effect by 6%). Simultaneously, statin treatment can upregulate PCSK9, further reducing the effectiveness of statins. Therefore, approximately 50% of individuals using statins cannot lower their LDL-C levels to the expected level. In addition, there are hepatotoxic and myotoxic side effects. The incidence of persistently elevated aminotransferase levels in the first three months of treatment is 0.5%-3.0%; myotoxicity includes myalgia, myositis, and rhabdomyolysis, with myositis and severe rhabdomyolysis being rare. Patients taking statins often experience statin intolerance.

[0006] The existing gold standard for treatment has significant disadvantages in terms of efficacy, tolerability, and compliance, and there is an urgent need for new target mechanisms to optimize medication regimens. The advent of the PCSK9 target has provided a solution for the development of new lipid-lowering drugs.

[0007] Proprotein convertase subtilisin / kexin type 9 (PCSK9) is a serine protease mainly synthesized and secreted by the liver. Under normal physiological function, most low-density lipoprotein cholesterol (LDL-C) binds to LDL receptors (LDL-R) on the surface of liver cells to form a complex, which is then engulfed by the liver cells. In the acidic environment of the liver, the two molecules dissociate, and LDL-C is gradually degraded in the lysosomes of the liver cells. After LDL-C dissociates, LDL-R returns to the surface of the liver cells to capture the remaining LDL-C and enter the next degradation cycle. However, PCSK9 can bind to LDL-R and then to LDL-C to form a new complex, which enters the lysosomes and is degraded together. This reduces the amount of free LDL-R in the blood, and consequently reduces the degradation of LDL-C, thus increasing the level of LDL-C.

[0008] Under pathological conditions, relevant research evidence indicates that mutations in the PCSK9 gene lead to increased PCSK9 protein expression, which in turn drives up LDL-C levels, contributing to familial hypercholesterolemia. Furthermore, mutations can effectively regulate lipid metabolism, affecting the development and progression of coronary heart disease. In human and animal models, studies have shown that statin treatment increases plasma PCSK9 levels, partially weakening the effect of statins on LDL-R expression and further reducing the effectiveness of statins.

[0009] PCSK9 monoclonal antibodies or siRNA drugs can further reduce LDL-C by at least 50% when used in conjunction with statin therapy. However, currently available PCSK9 monoclonal antibodies or siRNA drugs are generally expensive, have high production costs, and require injection. Therefore, there is an urgent need for the development of small molecule PCSK9 inhibitors that are safe, have few adverse reactions, can be taken orally, and are more economical.

[0010] There are already related patent studies on small molecule PCSK9 inhibitors worldwide, and those with positive clinical progress include AstraZeneca's small molecule chemical drug AZD0780 (Phase 3 clinical trial) WO2020150473A2. Summary of the Invention

[0011] On one hand, the present invention provides a compound of Formula I, or a stereoisomer thereof, or a pharmaceutically acceptable salt or prodrug thereof:

[0012]

[0013] Where L 1 L 2 L 3 and L 4 Each is independently selected from: CH or N, and L 1 L 2 L 3and L 4 No more than two of them are selected from N, and the rest are CH; R 1 Selected from: isopropyl, C 1-3 Halogenated alkyl or C 3-5 cycloalkyl; wherein the C 3-5 Each cycloalkyl group may optionally be substituted with one or more of the following substituents: hydrogen, halogen, halogenated C. 1-6 Alkyl or C 1-6 Alkyl; R 2 Selected from: hydrogen or halogen; R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl, C 1-3 Alkoxy or C 1-3 Halogenated alkyl; X is selected from O or S.

[0014] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, is described by Formula I-1:

[0015]

[0016] Where L 1 L 2 L 3 and L 4 Each is independently selected from: CH or N, and L 1 L 2 L 3 and L 4 No more than two of them are selected from N, and the rest are CH; R 1 Selected from: isopropyl, C 1-3 Halogenated alkyl or C 3-5 cycloalkyl; wherein the C 3-5 Each cycloalkyl group may optionally be substituted with one or more of the following substituents: hydrogen, halogen, halogenated C. 1-6 Alkyl or C 1-6 Alkyl; R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl, C 1-3 Alkoxy or C 1-3 Halogenated alkyl groups.

[0017] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, L 1 L 2 L 3 and L 4 Composition Selected from:

[0018]

[0019] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, is described by Formula I as being expressed by Formula I-2:

[0020]

[0021] X is selected from O or S; R 1’ Selected from: halogen or C 1-6 Alkyl, wherein the C 1-6 Alkyl groups may optionally be substituted with one or more of the following substituents: hydrogen or halogen; R 2 Selected from: hydrogen or halogen; L 1 L 2 L 3 and L 4 Each is independently selected from: CH or N, and L 1 L 2 L 3 and L 4 No more than two of them are selected from N, and the rest are CH; R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl or C 1-3 Alkoxy, wherein the C 1-3 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; n is independently selected from 0, 1 or 2.

[0022] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, is described in Formula I-2 as expressed in Formula I-2-1:

[0023]

[0024] R 1’ Selected from: Fluorine or C 1-3 Alkyl, wherein the C 1-3 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; n is independently selected from 0, 1 or 2.

[0025] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, is described by Formula I-2:

[0026]

[0027] R 1’ Selected from: Fluorine or C 1-3 Alkyl, wherein the C 1-3 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; n is independently selected from 0, 1 or 2.

[0028] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, R 1’ Selected from: fluorine, methyl or trifluoromethyl; n is independently selected from 0, 1 or 2.

[0029] In some embodiments, the compound, its stereoisomer, or its pharmaceutically acceptable salt is used. Selected from:

[0030] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, L 1 L 2 L 3 and L 4 Composition Selected from:

[0031]

[0032] R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl or C 1-3 Alkoxy, wherein the C 1-3 The alkyl group may optionally be substituted with one or more of the following substituents: hydrogen or halogen.

[0033] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl, C 1-3 Alkoxy or C 1-3 Halogenated alkyl groups.

[0034] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, R 3 Selected from: hydrogen, fluorine, chlorine, cyano, methyl, methoxy, difluoromethyl, or trifluoromethyl.

[0035] In some embodiments, the compound, or its stereoisomer, or its pharmaceutically acceptable salt, is selected from any of the following compounds:

[0036]

[0037]

[0038] In a second aspect, a pharmaceutical composition comprises the said compound, stereoisomer, or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers, diluents, or excipients.

[0039] In some embodiments, the compound or its pharmaceutically acceptable salt, its solvate, metabolite, cocrystal or prodrug, or the aforementioned composition is used in the preparation of a medicament for treating / preventing PCSK9-mediated diseases.

[0040] In some implementations, the disease is hyperlipidemia.

[0041] Detailed description of the invention

[0042] Unless otherwise stated, the terms used in the specification and claims shall have the following meanings.

[0043] "Alkyl" refers to a saturated aliphatic hydrocarbon group. It includes straight-chain or branched groups with 1 to 20 carbon atoms. Preferably, it is a medium-sized alkyl group containing 1 to 6 carbon atoms, such as methyl, ethyl, propyl, 2-propyl, n-butyl, isobutyl, tert-butyl, pentyl, etc. The alkyl group can be substituted or unsubstituted.

[0044] "Cx-y" is intended to include groups containing x to y carbons in the chain. For example, the term "C 1-6 "Alkyl" refers to a saturated hydrocarbon group, including straight-chain alkyl and branched-chain alkyl containing 1 to 6 carbons.

[0045] “Cx-y alkenyl” and “Cx-y ynyl” refer to unsaturated aliphatic groups with similar lengths and possible substitutions to the alkyl groups mentioned above, but each containing at least one double or triple bond.

[0046] “Cycloalkyl” refers to a saturated carbide ring. Exemplary cycloalkyl rings include cyclopropyl, cyclohexyl, and norbornene. Cycloalkyl groups may optionally be substituted with one or more substituents (such as those described herein).

[0047] "Heterocyclic alkyl" refers to a saturated or partially unsaturated monocyclic or polycyclic hydrocarbon substituent containing 3 to 20 ring atoms, one or more of which are heteroatoms selected from nitrogen, oxygen or S(0)m (where m is an integer from 0 to 2), but excluding the ring portion of -0-0-, -0-S- or -SS-, and the remaining ring atoms are carbon.

[0048] "Heteroaryl" or "heterocyclic" refers to an aromatic monocyclic structure, preferably a 5- or 6-membered ring, whose ring structure contains at least one heteroatom, preferably one to four heteroatoms, more preferably one or two heteroatoms. The term "heteroaryl" or "heterocyclic" also includes polycyclic systems having two or more rings, wherein two or more atoms are shared by two adjacent rings, wherein at least one of the rings is heteroaromatic; for example, the other rings may be aromatic or non-aromatic carbocyclic rings, or heterocyclic rings. Heteroaryl groups include, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrazine, pyridazine, and pyrimidine. Heteroaryl groups may optionally be substituted with one or more substituents (such as those described herein).

[0049] "Halogen" indicates fluorine, chlorine, bromine or iodine, preferably fluorine or chlorine.

[0050] The term "optionally" means that the event or situation described below may or may not occur, and the description includes both the possibility that the event or situation may or may not occur, and the description includes both the possibility that the event or situation occurs and the possibility that it does not occur. In some embodiments, "replaced by one or more groups" means that one, two, three, or four hydrogen atoms of a specified atom or group are replaced by the same or different groups selected from a specified range of groups.

[0051] Unless otherwise indicated, the structural formulas described in this invention include all isomers (e.g., enantiomers, diastereomers, and geometric isomers (or conformational isomers)): for example, R and S configurations containing an asymmetric center, (Z) and (E) isomers of double bonds, and (Z) and (E) conformational isomers. Therefore, any single stereochemical isomer of the compounds of this invention, or its enantiomers, diastereomers, or mixtures of geometric isomers (or conformational isomers), is within the scope of this invention.

[0052] The definitions and conventions of stereochemistry used in this invention are generally referenced in the following literature: S.P. Parker, Ed., McGraw-Hill Dictionary of Chemical Terms (1984); McGraw-Hill Book Company, New York; and Eliel J. E. and Wilen J. S., "Stereochemistry of Organic Compounds", John Wiley & Sons, Inc., New York, 1994. The compounds of this invention may contain asymmetric or chiral centers, and therefore exist as different stereoisomers. All stereoisomers of the compounds of this invention, including but not limited to diastereomers, enantiomers, stenotic isomers, and mixtures thereof, such as racemic mixtures, constitute a part of this invention. Many organic compounds exist in optically active forms, i.e., they are capable of rotating the plane of plane-polarized light. In describing optically active compounds, the prefixes D, L or R, S are used to indicate the absolute configuration of the chiral center of the molecule. The prefixes d, l or (+), (i) are used for naming. The symbol for the rotation of plane-polarized light of a compound, ∠ or 1, indicates that the compound is levorotatory, while the prefix ⑴ or d indicates that the compound is dextrorotatory. These stereoisomers have the same chemical structure, but their stereostructures differ. Specific stereoisomers can be enantiomers, and mixtures of isomers are usually called enantiomeric mixtures. A 50:50 enantiomeric mixture is called a racemic mixture or racemate, which may result in a lack of stereoselectivity or stereodirection during chemical reactions. The terms "racemic mixture" and "racemate" refer to a mixture of two equimolar enantiomers that lacks optical activity.

[0053] "Stereoisomers" are compounds that have the same chemical structure but whose atoms or groups are arranged differently in space. Stereoisomers include enantiomers, diastereomers, conformational isomers (rotational isomers), geometric isomers (cis / trans) isomers, and hindered isomers, etc.

[0054] The terms "tautomer" or "tautomerism form" refer to isomers of different energies that can interconvert through a low-energy barrier. For example, proton tautomers (i.e., proton-transfer tautomers) include interconversions via proton transfer, such as isomerization between keto-enol and imine-enamine forms. Valence tautomers include interconversions involving the recombination of bonding electrons.

[0055] "Chirality" refers to molecules that have the property that they cannot be superimposed on their mirror image; while "chirality" refers to molecules that can be superimposed on their mirror image.

[0056] "Enantiomers" refer to two non-overlapping but mirror-image isomers of a compound.

[0057] A diastereomer is a stereoisomer that has two or more chiral centers and whose molecules are not mirror images of each other. Diastereomers have different physical properties, such as melting point, boiling point, spectral properties, and reactivity. Mixtures of diastereomers can be separated by high-resolution analytical procedures such as electrophoresis and chromatography, for example, HPLC.

[0058] In some embodiments, the compositions of this disclosure may comprise two or more enantiomers or diastereomers of the compound, wherein a single enantiomer or diastereomer accounts for at least about 70% by weight, at least about 80% by weight, at least about 90% by weight, at least about 98% by weight, or at least about 99% by weight or more of the total weight of all stereoisomers. Methods for producing substantially pure enantiomers are well known to those skilled in the art.

[0059] In addition, heavier isotopes, especially deuterium (i.e., 2 Substitution with H or D can provide certain therapeutic advantages. These advantages result from increased metabolic stability, such as increased in vivo half-life, reduced dose requirement, or improved therapeutic index. It should be understood that deuterium in this invention is considered a suitable substituent for compounds of formulas (I), (II), (III), (IV), and (V).

[0060] Unless otherwise stated, the compounds described herein are intended to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds where hydrogen is replaced by deuterium or tritium, or where carbon is enriched. 13 C or 14 Compounds having the structure of this invention, other than carbon substitution of C, are within the scope of this disclosure. The compounds of this disclosure optionally contain atomic isotopes in non-natural proportions at one or more atoms constituting such compounds. For example, the compounds may use isotopes such as, for example, deuterium (₂H), tritium (₃H), etc. 3 H), iodine 125 ( 125 I) or carbon 14 ( 14 C) Mark. Use 2 H, 11 C 13 C 14 C 15 C 12 N、 13 N、 15 N、 16 N、 16 O、 17 O、 14 F, 15 F,16 F, 17 F, 18 F, 33 S, 34 S, 35 S, 36 S, 35 Cl、 37 Cl、 79 Br、 81 Br and 125 Isotopic substitutions of I are all considered. All isotopic variants of the compounds of this invention, whether or not they are radioactive, are covered within the scope of this invention.

[0061] "Pharmaceutically acceptable salts" refer to those salts that retain the bioavailability and properties of the parent compound. Such salts include: (1) salts formed by reacting the free base of the parent compound with an inorganic or organic acid, such as hydrochloric acid, hydrobromic acid, nitric acid, phosphoric acid, metaphosphoric acid, sulfuric acid, sulfurous acid, and perchloric acid, etc., and organic acids such as acetic acid, propionic acid, acrylic acid, oxalic acid, (D) or (L) malic acid, fumaric acid, maleic acid, hydroxybenzoic acid, γ-hydroxybutyric acid, methoxybenzoic acid, phthalic acid, methanesulfonic acid, ethanesulfonic acid, naphthalene-1-sulfonic acid, naphthalene-2-sulfonic acid, p-toluenesulfonic acid, salicylic acid, tartaric acid, citric acid, lactic acid, mandelic acid, succinic acid, or malonic acid, etc.

[0062] (2) Salts formed by replacing acidic protons in the parent compound with metal ions or by coordination with organic bases. Examples of metals include alkali metal ions, alkaline earth metal ions, or aluminum ions. Examples of organic bases include ethanolamine, diethanolamine, triethanolamine, tromethamine, N-methylglucosamine, etc.

[0063] "Pharmaceutical composition" refers to a mixture of one or more of the compounds of this invention, or their pharmaceutically acceptable salts, solvates, hydrates, or prodrugs, with other chemical components, such as a pharmaceutically acceptable carrier. The purpose of a pharmaceutical composition is to facilitate the administration of the drug to animals.

[0064] "Solvate" refers to an association formed by one or more solvent molecules with the compounds of this invention. Solvents that form solvates include, but are not limited to, water, isopropanol, ethanol, methanol, dimethyl sulfoxide, ethyl acetate, acetic acid, and aminoethanol. The term "hydrate" refers to an association formed when the solvent molecules are water.

[0065] "Pharmaceutical carrier" refers to an inactive ingredient in a pharmaceutical composition that does not cause significant irritation to the organism and does not interfere with the biological activity and properties of the given compound. Examples include, but are not limited to: calcium carbonate, calcium phosphate, various sugars (e.g., lactose, mannitol, etc.), starch, cyclodextrin, magnesium stearate, cellulose, magnesium carbonate, acrylic polymers or methacrylic polymers, gels, water, polyethylene glycol, propylene glycol, ethylene glycol, castor oil or hydrogenated castor oil or polyethoxylated hydrogenated castor oil, sesame oil, corn oil, peanut oil, etc.

[0066] In addition to pharmaceutically acceptable carriers, the aforementioned pharmaceutical compositions may also include pharmaceutically commonly used excipients, such as antibacterial agents, antifungal agents, antimicrobial agents, preservatives, colorants, solubilizers, thickeners, surfactants, complexing agents, proteins, amino acids, fats, sugars, vitamins, minerals, trace elements, sweeteners, pigments, flavorings, or combinations thereof. Specific Implementation

[0067] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] The structure of the compounds was determined by nuclear magnetic resonance (NMR) and mass spectrometry (MS). NMR was performed using a Bruker Avance III 400 NMR spectrometer with deuterated dimethyl sulfoxide (DMSO-d6), deuterated chloroform (CDCl3), and deuterated methanol (CD3OD) as solvents, and tetramethylsilane (TMS) as the internal standard. LC-MS was performed using a Shimadzu LC-MS 2020 (ESI) system. HPLC was performed using a Shimadzu LC-20A system. MPLC (medium-pressure preparative chromatography) was performed using a Gilson GX-281 reversed-phase preparative chromatograph. Thin-layer chromatography (TLC) used Yantai Huanghai HSGF254 or Qingdao GF254 silica gel plates, with a thickness of 0.4 mm to 0.5 mm for product separation and purification. Silica gel column chromatography generally used Yantai Huanghai 200–300 mesh silica gel as the support. Chiral separation of SFC was performed using a Shimadzu LC-30AD SFC system.

[0069] In the examples, commonly used organic solvents are referred to using abbreviations well known in the art, such as: DCM refers to dichloromethane; THF refers to tetrahydrofuran; Dioxane refers to 1,4-dioxane; DMF refers to N,N-dimethylformamide; MeOH refers to methanol; EtOH refers to ethanol; HOAc refers to acetic acid; NMI refers to ethyl N-methylimidazole, etc.

[0070] Example 1

[0071] Intermediate 1f: 2-hydroxy-1-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine(1f)

[0072]

[0073] Step 1: Preparation of (1S,3S)-3-((5-iodopyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (1b)

[0074] Under nitrogen protection, tert-butyl [(1S,3S)-3-aminocyclopentyl]carbamate (1a) (1.20 g, 6.00 mmol) and 2-fluoro-5-iodopyridine (1.61 g, 7.20 mmol) were dispersed in DMSO (30 mL), and N,N-diisopropylethylamine (2.33 g, 18.00 mol) was added. The mixture was reacted at 120 °C for 3 hours to terminate the reaction. After the reaction, the mixture was extracted with ethyl acetate, and the organic layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 0%–5%) to give tert-butyl (1S,3S)-3-((5-iodopyridine-2-yl)amino)cyclopentyl)carbamate (1b).

[0075] 1 H NMR (400MHz, DMSO-d6) δ8.09(d,J=2.4Hz,1H),7.56(dd,J=8.8,2.4Hz,1H),6.87(d,J=6.4Hz,1H),6.73(d,J=6.8Hz,1H),6.35(d, J=8.8Hz,1H),4.16–4.08(m,1H),3.94–3.86(m,1H),2.04-2.00(m,1H),1.98-1.90(m,1H),1.75-1.63(m,2H),1.42–1.31(m,11H).

[0076] Step 2: Preparation of (1S,3S)-3-((5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (1c)

[0077] Under nitrogen atmosphere, 5-hydro-6-hydro-pyridine[3,4-b]pyridin-7-one (0.20 g, 1.49 mmol), (1S,3S)-3-((5-iodopyridin-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (1b) (0.90 g, 2.23 mmol), and tripotassium phosphate (1.42 g, 6.70 mmol) were dispersed in isopropanol (20 mL), followed by the addition of cuprous iodide (0.34 g, 1.78 mmol) and N,N'-dimethyl-1,2-cyclohexanediamine (0.25 g, 1.78 mmol). The mixture was reacted at 60 °C for 12 hours until the reaction was terminated. After the reaction was complete, the mixture was filtered and concentrated. The crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 0%-5%) to obtain (1S,3S)-3-((5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (1c).

[0078] 1 H NMR(400MHz,DMSO-d6)δ8.36(s,1H),8.13(d,J=7.6Hz,1H),7.87(d,J=8.8H z,1H),7.67(s,1H),6.88(d,J=7.6Hz,1H),6.61(d,J=6.8Hz,1H),6.53(d,J= 8.8Hz,1H),4.94(s,2H),4.25–4.16(m,1H),3.98-3.89(m,1H),2.11-2.05(m ,1H),1.99-1.93(m,1H),1.82-1.69(m,2H),1.45-1.40(m,2H),1.38(s,9H).

[0079] Step 3: Preparation of 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (1d)

[0080] Under nitrogen atmosphere, tert-butyl carbamate (1c) (0.40 g, 0.97 mmol) was dispersed in ethyl acetate (12 mL, 0.4 M) solution of hydrochloric acid. The mixture was stirred at 20 °C for 3 hours until the reaction was terminated. After the reaction was completed, the product was concentrated to give 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (1d). The product was used directly in the next step without further purification.

[0081] LCMS(ESI)calcd for C 17 H 19 N5O[M+H] + m / z 310, found 310.3.

[0082] Step 4: Preparation of N-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (1e)

[0083] 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (1d) (0.50 g, 1.61 mmol) was dispersed in a tetrahydrofuran (10 mL) solution, followed by the addition of bromocyanide (0.18 g, 1.77 mmol) and N,N-diisopropylethylamine (0.63 g, 4.84 mmol). The mixture was reacted at 20 °C for 1 hour until the reaction was terminated. After the reaction was completed, the mixture was filtered and concentrated. The crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 0%-5%) to obtain N-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (1e).

[0084] 1H NMR (400MHz, DMSO-d6) δ8.76(d,J=4.4Hz,1H),8.37(d,J=2.4Hz,1H),8.11(d,J= 7.6Hz,1H),7.90(d,J=6.8Hz,1H),7.62(dd,J=7.8,4.8Hz,1H),6.89(s,1H),6.7 3(s,1H),6.55(d,J=8.4Hz,1H),4.94(s,2H),4.30-4.25(m,1H),3.74-3.70(m,1 H),2.17–2.07(m,1H),2.07–1.90(m,2H),1.79-1.72(m,1H),1.51-1.41(m,2H).

[0085] Step 5: Preparation of 2-hydroxy-1-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (1f)

[0086] Under nitrogen atmosphere, N-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (1e) (0.60 g, 1.79 mmol) was dispersed in ethanol (1 mL), followed by the addition of triethylamine (0.1 mL) and hydroxylamine hydrochloride (0.12 g, 1.79 mmol). The mixture was reacted at 60 °C for 2 hours until termination. Concentration yielded 2-hydroxy-1-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (1f). The product was used directly in the next step without further purification.

[0087] LCMS(ESI)calcd for C 18 H 21 N7O2[M+H] + m / z 368, found 368.3.

[0088] Example 2: 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 2)

[0089]

[0090] Step 1: Preparation of 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 2)

[0091] 2-hydroxy-1-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (1f) (0.05 g, 0.13 mmol) was dispersed in DMF (0.5 mL), and a mixed solution of cyclopropionic acid (0.03 g, 0.32 mmol) and 1,1′-carbonyldiimidazole (0.05 g, 0.32 mmol) in DMF (0.5 mL) was added. The reaction was terminated at 60 °C for 16 hours. The compound was prepared by high performance liquid chromatography (0.05% ammonia-acetonitrile system, 15%-85%, 15 min, 20 mL / min) to obtain the product 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 2).

[0092] LCMS(ESI)calcd for C 22 H 23 N7O2[M+H] + m / z 418.4, found 418.3.

[0093] 1 H NMR (400MHz, DMSO-d6) δ8.75(d,J=4.0Hz,1H),8.35(d,J=2.4Hz,1H),8.11(d,J=7.6Hz,1H),7.8 7(dd,J=8.8,2.8Hz,1H),7.62(dd,J=7.6,4.8Hz,1H),6.80(d,J=6.8Hz,1H),6.66(d,J=6.8Hz,1 H),6.54(d,J=8.8Hz,1H),4.93(s,2H),4.31–4.21(m,1H),3.90–3.79(m,1H),2.17–2.02(m,3H) ,1.96–1.87(m,1H),1.85–1.71(m,1H),1.58–1.39(m,2H),1.18–1.09(m,2H),1.02–0.92(m,2H).

[0094] Example 3: 6-(6-((1S,3S)-3-((5-(difluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 3)

[0095]

[0096] Step 1: Preparation of 6-(6-((1S,3S)-3-((5-(difluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 3)

[0097] 2-Hydroxy-1-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (1f) (0.10 g, 0.27 mmol) was dispersed in difluoroacetic anhydride (0.5 mL), and the mixture was reacted at 25 °C for 2 h to terminate the reaction. The compound was prepared by high performance liquid chromatography (0.05% ammonia-acetonitrile system, 15%-85%, 15 min, 20 mL / min) to give product 6-(6-((1S,3S)-3-((5-(difluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 3). LCMS(ESI)calcd for C 20 H 19 F2N7O2[M+H] + m / z 428.3, found 428.2.

[0098] 1 H NMR (400MHz, DMSO-d6) δ8.76(d,J=4.4Hz,1H),8.36(d,J=2.4Hz,1H),8.11(d,J=7.6Hz,1H ),7.88(dd,J=8.8,2.8Hz,1H),7.62(dd,J=7.6,4.8Hz,1H),7.43(s,1H),7.29(t,J=52.0H z,1H),6.70(d,J=6.8Hz,1H),6.55(d,J=9.2Hz,1H),4.93(s,2H),4.36–4.24(m,1H),3.98 –3.88(m,1H),2.16-2.09(m,2H),2.02–1.92(m,1H),1.88–1.82(m,1H),1.62–1.44(m,2H).

[0099] Example 4: 6-(6-(((1S,3S)-3-((5-(cyclopropylfluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 4)

[0100]

[0101] Step 1: Preparation of 6-(6-(((1S,3S)-3-((5-(cyclopropylfluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 4)

[0102] 1-Fluorocyclopropane-1-carboxylic acid (0.04 g, 0.40 mmol) was dispersed in DCM (1 mL), and N-methylimidazolium (0.03 g, 0.40 mmol) and N,N,N',N'-tetramethylchloromethamine hexafluorophosphate (0.01 g, 0.40 mmol) were added. The mixture was reacted at 25 °C for 1 hour, and then a solution of 2-hydroxy-1-((1S,3S)-3-(5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (1f) (0.10 g, 0.27 mmol) in DCM (1 mL) was added. The mixture was reacted at 35 °C for 72 hours to terminate the reaction. The compound was prepared by high performance liquid chromatography (0.05% ammonia-acetonitrile system, 15%-85%, 15 min, 20 mL / min) to obtain the product 6-(6-(((1S,3S)-3-((5-(cyclopropylfluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 4).

[0103] LCMS(ESI)calcd for C 22 H 22 FN7O2[M+H] + m / z 436.2, found 436.3.

[0104] 1H NMR (400MHz, DMSO-d6) δ8.75(d,J=4.8Hz,1H),8.35(d,J=2.8Hz,1H),8.11(d,J=7.6Hz,1H),7.8 7(dd,J=9.2,2.8Hz,1H),7.62(dd,J=7.6,4.8Hz,1H),7.11(d,J=6.8Hz,1H),6.68(d,J=6.8Hz,1 H),6.54(d,J=9.2Hz,1H),4.93(s,2H),4.32–4.22(m,1H),3.94–3.83(m,1H),2.14–2.06(m,2H) ,2.00-1.91(m,1H),1.85–1.79(m,1H),1.74-1.67(m,2H),1.55-1.46(m,2H),1.44–1.36(m,2H).

[0105] Example 5: 6-(6-((1S,3S)-3-((5-isopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 5)

[0106]

[0107] Referring to the synthesis scheme of Example 4, isobutyric acid was used as a reactant to obtain the target product 6-(6-((1S,3S)-3-((5-isopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 5).

[0108] LCMS(ESI)calcd for C 22 H 25 N7O2[M+H] + m / z 420.2, found 420.3.

[0109] 1H NMR (400MHz, CDCl3) δ8.87(d,J=4.4Hz,1H),8.65(d,J=9.2Hz,1H),8.15(s,1H),7.94( d,J=7.6Hz,1H),7.57–7.51(m,1H),6.76(d,J=9.6Hz,1H),4.82(s,2H),4.45–4.36(m, 1H),4.29–4.19(m,1H),4.15-4.10(m,1H),3.07(dt,J=14.0,7.2Hz,1H),2.41-2.34(m ,2H),2.26–2.10(m,1H),2.11–2.03(m,1H),1.74–1.70(m,2H),1.35(d,J=6.8Hz,6H).

[0110] Example 6: 6-(6-((1S,3S)-3-((5-(trifluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 6)

[0111]

[0112] Referring to the synthesis scheme of Example 3, trifluoroacetic anhydride was used as a reactant to obtain the target product 6-(6-((1S,3S)-3-((5-(trifluoromethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 6).

[0113] LCMS(ESI)calcd for C 20 H 18 F3N7O2[M+H] + m / z 446, found 446.3.

[0114] 1H NMR (400MHz, DMSO-d6) δ8.76(d,J=4.4Hz,1H),8.36(d,J=2.4Hz,1H),8.12(d,J= 7.6Hz,1H),7.91(d,J=8.0Hz,1H),7.71(d,J=6.8Hz,1H),7.62(dd,J=7.6,4.8Hz ,1H),6.74(s,1H),6.57(s,1H),4.94(s,2H),4.36–4.25(m,1H),4.01–3.88(m,1 H),2.20–2.09(m,2H),2.03–1.95(m,1H),1.91–1.82(m,1H),1.62–1.46(m,2H).

[0115] Example 7: 6-(6-((1S,3S)-3-((5-(1,1-difluoroethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 7)

[0116]

[0117] Referring to the synthesis scheme of Example 4, 2,2-difluoropropionic acid was used as the reactant to obtain the target product 6-(6-((1S,3S)-3-((5-(1,1-difluoroethyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 7).

[0118] LCMS(ESI)calcd for C 21 H 21 F2N7O2[M+H] + m / z 442, found 442.3.

[0119] 1H NMR (400MHz, DMSO-d6) δ8.76(d,J=4.0Hz,1H),8.36(d,J=2.8Hz,1H),8.11(d,J=7.6Hz,1H) ,7.88(dd,J=9.2,2.8Hz,1H),7.62(dd,J=7.6,4.8Hz,1H),7.44(d,J=6.8Hz,1H),6.71(d,J =6.8Hz,1H),6.55(d,J=9.2Hz,1H),4.93(s,2H),4.34–4.23(m,1H),3.98–3.86(m,1H),2.1 5–2.08(m,4H),2.03–1.93(m,2H),1.89–1.81(m,1H),1.63–1.55(m,1H),1.51–1.46(m,1H).

[0120] Referring to the synthesis scheme of Example 2, the following compounds were synthesized:

[0121]

[0122]

[0123]

[0124] Example 13: 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-thiadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 13)

[0125]

[0126] Step 1: Preparation of 3-bromo-5-cyclopropyl-1,2,4-thiadiazole (13a)

[0127] Under nitrogen protection at room temperature, 3-bromo-5-chloro-1,2,4-thiadiazole (0.80 g, 4.04 mmol), cyclopropylboronic acid (0.52 g, 6.06 mmol), cesium carbonate (2.61 g, 8.08 mmol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride dichloromethane complex (0.29 g, 0.40 mmol) were dispersed in a mixed solvent of toluene and water (10:1, 11 mL) and the reaction was terminated at 80 °C for 16 hours. After the reaction, the mixture was filtered and concentrated. The crude product was purified by silica gel column chromatography (elution: dichloromethane:methanol = 10:1-5:1) to obtain the target compound 3-bromo-5-cyclopropyl-1,2,4-thiadiazole (13a).

[0128] LCMS(ESI)calcd for C5H5BrN2S[M+H] + m / z 205, found 204.90.

[0129] Step 2: Preparation of 5-cyclopropyl-3-iodo-1,2,4-thiadiazole (13b)

[0130] Under nitrogen protection at room temperature, 3-bromo-5-cyclopropyl-1,2,4-thiadiazole (13a) (0.55 g, 2.68 mmol), sodium iodide (3.22 g, 21.46 mmol), cuprous iodide (0.51 g, 2.68 mmol), and N,N-dimethylethylenediamine (0.24 g, 2.62 mmol) were dispersed in 1,4-dioxane (7 mL), and the reaction was terminated at 90 °C for 2 hours. After the reaction, the mixture was extracted and concentrated. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate: petroleum ether = 0%–3%) to give the target compound 5-cyclopropyl-3-iodo-1,2,4-thiadiazole (13b).

[0131] LCMS(ESI)calcd for C5H5IN2S[M+H] + m / z 252.92, found 252.85.

[0132] Step 3: Preparation of 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-thiadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 13)

[0133] 5-Cyclopropyl-3-iodo-1,2,4-thiadiazole (13b) (0.04 g, 0.16 mmol), (6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (1d) (0.05 g, 0.16 mmol), dichloro[1,3-bis(2,6-di-3-pentylphenyl)imidazol-2-ylidene](3-chloropyridinyl)palladium(II) (14 mg, 0.01 mmol) and cesium carbonate (0.16 g, 0.48 mmol) was dissolved in ultra-dry 1,4-dioxane (10 mL), and the mixture was reacted at 80 °C under nitrogen for 1 hour to terminate the reaction. After the reaction, the mixture was extracted, washed, dried, filtered, and concentrated. The compound was prepared by high performance liquid chromatography (acetonitrile / water system - 0.1% FA) to give the target product 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-thiadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 13). LCMS (ESI) calcd for C 22 H 23 N7OS[M+H] + m / z 434, found 433.95.

[0134] 1 H NMR (400MHz, DMSO-d6) δ8.75(d,J=3.6Hz,1H),8.35(d,J=2.4Hz,1H),8.11(d,J=7.6Hz,1H),7.87(dd ,J=9.2,2.8Hz,1H),7.61(dd,J=7.6,4.8Hz,1H),7.35(d,J=6.8Hz,1H),6.66(d,J=6.4Hz,1H),6.54( d,J=9.2Hz,1H),4.93(s,2H),4.28-4.23(m,1H),4.17-4.12(m,1H),2.45-2.41(m,1H),2.13-2.08(m ,2H),1.95-1.89(m,1H),1.86-1.79(m,1H),1.55-1.44(m,2H),1.22-1.17(m,2H),1.02-0.98(m,2H).

[0135] Example 14: 2-(6-(((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (Compound 14)

[0136]

[0137] Step 1: Preparation of ((1S,3S)-3-((5-nitropyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (14a)

[0138] At room temperature, 2-fluoro-5-nitropyridine (3.90 g, 27.45 mmol) and N,N-diisopropylethylamine (9.70 g, 75.00 mmol) were added to a stirred solution of ((1S,3S)-3-aminocyclopentyl)carbamate (1a) (5.00 g, 24.87 mmol) in 100 mL of dimethyl sulfoxide. The reaction mixture was then heated to 130 °C and stirred for 2 hours under nitrogen protection until the reaction was terminated. The mixture was diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated, and the crude product was dispersed in ethyl acetate (60 mL), petroleum ether (60 mL) was added, and the mixture was stirred for another 40 minutes before filtration. The filter cake was dried to give the target compound ((1S,3S)-3-((5-nitropyridine-2-yl)amino)cyclopentyl)carbamate (14a). LC-MS(ESI)calcd for C 15 H 22 N4O4[M+H] + m / z 323.2, found 323.2.

[0139] 1 H NMR (400MHz, CDCl3) δ9.00(d,J=2.4Hz,1H),8.18(dd,J=9.2,2.4Hz,1H),6.34(d,J=9.2Hz,1H),5.34(s,1H),4.54(s ,1H),4.32(s,1H),4.13(d,J=5.2,5.2Hz,1H),2.35-2.05(m,2H),2.00-1.95(m,2H),1.59-1.50(m,2H),1.48(s,9H).

[0140] Step 2: Preparation of ((1S,3S)-3-((5-aminopyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (14b)

[0141] ((1S,3S)-3-((5-nitropyridin-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (14a) (5.98 g, 18.60 mmol) and 10% wet palladium on carbon (1.50 g) were dispersed in ethyl acetate (500 mL) at room temperature. The reaction mixture was stirred at 35 °C under a hydrogen atmosphere for 16 hours until the reaction was terminated. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated to give the crude target compound ((1S,3S)-3-((5-aminopyridin-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (14b). The crude product was used directly in the next step without further purification.

[0142] LC-MS(ESI)calcd for C 15 H 24 N4O2[M+H] + m / z 293.2, found 293.2.

[0143] Step 3: Preparation of 2,5-dioxopyrrolidone-1-ylcyclopropane carboxylate (14c)

[0144] N,N'-dicyclohexylcarbodiimide (8.60 g, 41.76 mmol) was added to a stirred solution of cyclopropane carboxylic acid (3.00 g, 34.80 mmol) in dichloromethane (30 mL) at 0 °C. After stirring for 30 minutes, N-hydroxysuccinimide (4.80 g, 41.76 mmol) was added. The reaction mixture was heated to room temperature and stirred for 2 hours to terminate the reaction. The reaction mixture was filtered, concentrated to obtain a crude product, and separated by silica gel column chromatography (eluent: petroleum ether / ethyl acetate = 10 / 1 to 1 / 1) to obtain the target compound 2,5-dioxopyrrolidone-1-ylcyclopropane carboxylic acid ester (14c).

[0145] 1 H NMR (400MHz, CDCl3) δ2.83(s,4H),1.93-1.87(m,1H),1.28-1.21(m,2H),1.20-1.13(m,2H).

[0146] Step 4: Preparation of methyl 3-(chloromethyl)isonicotinic acid (14d)

[0147] Under nitrogen protection, N-chlorosuccinimide (3.57 g, 26.79 mmol), azoisobutyronitrile (0.29 g, 1.78 mmol), and acetic acid (1 mL) were added dropwise to a stirred chloroform (30 mL) solution of methyl 3-methylisonicotinic acid (2.70 g, 17.86 mmol). The reaction mixture was then heated to 80 °C and stirred under nitrogen protection for 16 hours until the reaction was terminated. The reaction mixture was diluted with water and extracted with dichloromethane. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated, and the crude residue was separated by silica gel column chromatography (eluent: dichloromethane / methanol = 25 / 1) to give the target compound methyl 3-(chloromethyl)isonicotinic acid (14 d).

[0148] 1 H NMR (400MHz, CDCl3) δ8.81 (s, 1H), 8.73 (d, J = 5.0Hz, 1H), 7.78 (d, J = 5.0Hz, 1H), 5.01 (s, 2H), 3.99 (s, 3H).

[0149] Step 5: Preparation of ((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (14e)

[0150] 3-(chloromethyl)isonicotinic acid methyl ester (14d) (0.38 g, 2.05 mmol) was dissolved in isopropanol (6 mL) at room temperature. Tert-butyl ((1S,3S)-3-((5-aminopyridin-2-yl)amino)cyclopentyl)carbamate (14b) (0.50 g, 1.71 mmol) and N,N-diisopropylethylamine (0.66 g, 5.13 mmol) were slowly added. The reaction mixture was heated to 100 °C and stirred for 16 hours until the reaction was terminated. The reaction mixture was cooled to room temperature, concentrated, diluted with water, and extracted with dichloromethane. The organic phase was washed with water, washed with saturated brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated, and the crude product was separated by silica gel column chromatography (eluent: dichloromethane / methanol = 25 / 1) to obtain the target compound ((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (14e).

[0151] LC-MS(ESI)calcd for C 22 H 27 N5O3[M+H] + m / z 410.2, found 410.2.

[0152] Step 6: Preparation of 2-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (14f)

[0153] Under nitrogen protection, at 0°C, a solution of hydrogen chloride / 1,4-dioxane (4 mL) was slowly added to a stirred solution of ((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (14e) (0.24 g, 0.59 mmol) in 4 mL of dry dichloromethane. The reaction mixture was then stirred at room temperature under nitrogen protection for 2 hours until the reaction was terminated. The reaction mixture was concentrated to give the crude target compound 2-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (14f). The crude compound was used directly in the next step of the reaction without further purification.

[0154] LC-MS(ESI)calcd for C 17 H 19 N5O[M+H] + m / z 310.2, found 310.1.

[0155] Step 7: Preparation of N-((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (14g)

[0156] Under nitrogen protection, cyanogen bromide (0.18 g, 1.75 mmol) and N,N-diisopropylethylamine (0.52 g, 4.06 mmol) were added in portions to a stirred solution of 2-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (14f) (0.26 g, 0.59 mmol) in 4 mL of dry tetrahydrofuran. The reaction mixture was then stirred at room temperature under nitrogen protection for 1 hour to terminate the reaction. The reaction was filtered and concentrated to obtain crude target compound N-((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (14 g). The crude product was used directly in the next step of the reaction without further purification.

[0157] LC-MS(ESI)calcd for C 18 H 18N6O[M+H] + m / z 335.2; found 335.1.

[0158] Step 8: Preparation of (E)-2-hydroxy-1-((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (14h)

[0159] Hydroxylamine hydrochloride (0.14 g, 2.01 mmol) and triethylamine (0.20 g, 2.01 mmol) were added to a 2 mL ethanol solution of N-((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (14 g) (0.08 g, 0.17 mmol). The reaction mixture was then heated to 60 °C and stirred for 2 hours to terminate the reaction. The cooled reaction solution was concentrated, and the resulting residue was purified by reversed-phase C18 column chromatography (mobile phase: 0.1% formic acid aqueous solution / acetonitrile). After concentration, the target compound (E)-2-hydroxy-1-((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (14h).

[0160] 1 H NMR (400MHz, DMSO-d6) δ8.96 (s, 1H), 8.77 (d, J = 5.0Hz, 1H), 8.55 (brs, 1H), 8.41-8.25 (m, 3H),7.87(dd,J=9.0,2.7Hz,1H),7.73(d,J=4.9Hz,1H),7.60(brs,2H),6.69(d,J=6.4Hz,1 H),6.54(d,J=9.0Hz,1H),5.03(s,2H),4.26-4.20(m,J=12.8,6.5Hz,1H),3.97(s,1H),2.1 3-2.07(m,J=11.7,5.8Hz,2H),1.92-1.86(m,J=26.9,13.3,6.8Hz,2H),1.58-1.40(m,2H).

[0161] Step 9: Preparation of 2-(6-(((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (compound 14)

[0162] At room temperature, 2,5-dioxopyrrolidone-1-((1S,3S)-3-((5-(1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (14 h) (0.03 g, 0.08 mmol) in N-methylpyrrolidone (1 mL) was added to a stirred solution of 2,5-dioxopyrrolidone-1-ylcyclopropanecarboxylate (14 c) (0.02 g, 0.10 mmol) and N,N-diisopropylethylamine (0.08 g, 0.65 mmol). The reaction mixture was then heated to 70 °C and stirred for 16 hours to terminate the reaction. The reaction solution was concentrated, and the resulting residue was separated by high performance liquid chromatography (mobile phase: 0.1% formic acid aqueous solution / acetonitrile), concentrated, and the target product 2-(6-(((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (compound 14).

[0163] LC-MS(ESI)calcd for C 22 H 23 N7O2[M+H] + m / z 418.2, found 418.2.

[0164] 1 H NMR (400MHz, DMSO-d6) δ8.96(s,1H),8.77(d,J=5.0Hz,1H),8.34(d,J=2.5Hz,1H),7.85(dd,J=9.0,2 .6Hz,1H),7.73(d,J=4.9Hz,1H),6.79(d,J=6.8Hz,1H),6.69(d,J=6.8Hz,1H),6.54(d,J=9.0Hz,1H), 5.03(s,2H),4.26(dd,J=12.9,6.5Hz,1H),3.85(dd,J=13.1,6.6Hz,1H),2.15-2.02(m,3H),1.95-1.8 9(m,J=13.3,6.8Hz,1H),1.84-1.74(m,1H),1.54-1.43(m,2H),1.17-1.09(m,2H),1.01-0.94(m,2H).

[0165] Referring to the synthesis scheme of Example 14, the following compounds were synthesized:

[0166]

[0167]

[0168] Example 17: 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 17)

[0169]

[0170] Step 1: Preparation of methyl 3-cyano-6-methylpyridine-2-carboxylate (17a)

[0171] In a high-pressure reactor at room temperature, 2-chloro-6-methylpyridin-3-onitrile (5.00 g, 32.80 mmol), triethylamine (9.96 g, 98.40 mmol), and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride dichloromethane complex (2.68 g, 0.33 mmol) were dispersed in methanol (50 mL). The mixture was reacted at 100 °C under CO (3 MPa) for 16 hours. After the reaction, the mixture was filtered and concentrated. The crude product was purified by silica gel column chromatography (elution: petroleum ether: ethyl acetate = 10:1-3:1) to give the target compound methyl 3-cyano-6-methylpyridin-2-carboxylate (17a).

[0172] 1 H NMR (400MHz, CDCl3) δ8.03 (d, J = 8.0 Hz, 1H), 7.47 (d, J = 8.0 Hz, 1H), 4.07 (s, 3H), 2.74 (s, 3H).

[0173] Step 2: Preparation of 2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (17b)

[0174] methyl 3-cyano-6-methylpyridine-2-carboxylate (17a) (2.50 g, 14.20 mmol) and Raney nickel (2.43 g, 28.40 mmol) were dispersed in methanol (30 mL) at room temperature, and the mixture was reacted at 50 °C under a hydrogen atmosphere for 16 hours. After the reaction, the mixture was filtered and concentrated. The crude product was purified by silica gel column chromatography (elution: dichloromethane:methanol = 50:1-10:1) to give the target compound 2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (17b).

[0175] 1 H NMR (400MHz, DMSO-d6) δ8.86 (s, 1H), 7.91 (d, J = 8.0 Hz, 1H), 7.42 (d, J = 8.0 Hz, 1H), 4.33 (s, 2H), 2.57 (s, 3H).

[0176] Step 3: Preparation of (1S,3S)-3-((5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (17c)

[0177] Under nitrogen atmosphere at room temperature, 2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (17b) (0.50 g, 3.37 mmol), (1S,3S)-3-((5-iodopyridin-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (1b) (2.05 g, 5.06 mmol), potassium phosphate (3.22 g, 15.19 mmol), cuprous iodide (0.77 g, 4.05 mmol), and N,N'-dimethyl-1,2-cyclohexanediamine (0.58 g, 4.05 mmol) were dispersed in isopropanol (10 mL). The mixture was reacted at 60 °C for 16 hours until the reaction was terminated. After the reaction was completed, the mixture was filtered, extracted, and concentrated. The crude product was purified by silica gel column chromatography (elution: dichloromethane:methanol = 50:1-10:1) to obtain the target compound (1S,3S)-3-((5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (17c).

[0178] 1 H NMR (400MHz, DMSO-d6) δ8.34 (s, 1H), 7.98 (d, J = 8.0Hz, 1H), 7.86 (dd, J = 9.2, 2.8Hz,1H),7.48(d,J=8.0Hz,1H),6.90(d,J=7.2Hz,1H),6.62(d,J=6.8Hz,1 H),6.53(d,J=9.2Hz,1H),4.87(s,2H),4.20(d,J=5.6Hz,1H),3.93(s,1H),2 .60(s,3H),2.11–2.02(m,1H),1.95(s,1H),1.83–1.69(m,2H),1.38(s,11H).

[0179] Step 4: Preparation of 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (17d)

[0180] At room temperature, tert-butyl carbamate (1S,3S)-3-((5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)carbamate (17c) (0.30 g, 0.71 mmol) was dispersed in hydrochloric acid / 1,4-dioxane solution (4 mol / L, 5 mL). The mixture was reacted at 25 °C for 2 hours until the reaction was terminated. After the reaction was completed, the mixture was concentrated to give the crude target compound 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (17d).

[0181] 1 H NMR(400MHz,DMSO-d6)δ8.50(d,J=2.0Hz,1H),8.36(dd,J=9.6,2.4Hz,1H),8.21 (s,3H),8.06(d,J=8.0Hz,1H),7.55(d,J=8.0Hz,1H),7.26(d,J=9.6Hz,1H),4.9 7(s,2H),4.42(d,J=30.6Hz,1H),3.71(d,J=6.4Hz,1H),2.61(s,3H),2.35–2.25 (m,1H),2.17(d,J=20.4,13.2,7.2Hz,2H),2.07–1.99(m,1H),1.76–1.61(m,2H).

[0182] Step 5: Preparation of N-((1S,3S)-3-((5-(1-oxoisoindoline-2-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (17e)

[0183] At room temperature, 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (17d) (0.20 g, 0.62 mmol), cyanogen bromide (0.10 g, 0.93 mmol), and N,N-diisopropylethylamine (0.24 g, 1.86 mmol) were dissolved in N,N-dimethylformamide (5 mL), and the mixture was reacted at 25 °C for 2 hours to terminate the reaction. After the reaction was completed, the mixture was extracted and concentrated. The crude product was purified by silica gel column chromatography (elution: dichloromethane:methanol = 50:1-10:1) to give the target compound N-((1S,3S)-3-((5-(1-oxoisoindoline-2-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (17e).

[0184] 1H NMR (400MHz, DMSO-d6) δ8.35(d,J=2.6Hz,1H),7.98(d,J=8.0Hz,1H),7.89(dd,J=9.2 ,2.8Hz,1H),7.48(d,J=8.0Hz,1H),6.84(d,J=4.4Hz,1H),6.67(d,J=6.8Hz,1H),6.5 3(d,J=9.2Hz,1H),4.87(s,2H),4.27(dd,J=13.2,6.8Hz,1H),3.80–3.64(m,1H),2.6 0(s,3H),2.19–2.06(m,1H),2.05–1.90(m,2H),1.82–1.70(m,1H),1.58–1.42(m,2H).

[0185] Step 6: Preparation of (E)-2-hydroxy-1-((1S,3S)-3-(5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (17f)

[0186] At room temperature, N-((1S,3S)-3-(5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (17e) (0.15 g, 0.43 mmol), hydroxylamine hydrochloride (0.08 g, 1.08 mmol), and triethylamine (0.18 g, 1.72 mmol) were dispersed in ethanol (5 mL), and the mixture was reacted at 80 °C for 2 hours. After the reaction, the mixture was concentrated to obtain the crude target compound (E)-2-hydroxy-1-((1S,3S)-3-(5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (17f). The product was used directly in the next step without further purification.

[0187] LCMS(ESI)calcd for C 19 H 23 N7O2[M+H] + m / z 382, ​​found 382.3.

[0188] Step 7: Preparation of 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 17)

[0189] At room temperature, (E)-2-hydroxy-1-((1S,3S)-3-(5-(2-methyl-7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)guanidine (17f) (0.16 g, 0.25 mmol) and 2,5-dioxopyrrolidone-1-ylcyclopropane carboxylate (0.14 g, 0.74 mmol) were dispersed in N-methylpyrrolidone (5 mL). The mixture was reacted at 70 °C for 16 hours until the reaction was terminated. After the reaction was completed, the mixture was extracted and concentrated. The compound was prepared by high performance liquid chromatography (0.05% formic acid-acetonitrile system, 15%-85%, 20 mL / min) to obtain the target product 6-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-2-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 17).

[0190] LCMS(ESI)calcd for C 23 H 25 N7O2[M+H] + m / z 432.2, found 432.0.

[0191] 1H NMR (400MHz, DMSO-d6) δ8.34(s,1H),7.98(d,J=8.0Hz,1H),7.87(d,J=8.8Hz,1H),7.48(d, J=7.6Hz,1H),6.79(d,J=6.8Hz,1H),6.65(d,J=6.4Hz,1H),6.54(d,J=8.8Hz,1H),4.87(s,2 H),4.25(d,J=6.4Hz,1H),3.85(dd,J=12.8,6.4Hz,1H),2.59(s,3H),2.15–2.02(m,3H),1.9 6–1.87(m,1H),1.84–1.74(m,1H),1.56–1.39(m,2H),1.17–1.10(m,2H),1.02–0.95(m,2H).

[0192] Referring to the synthesis scheme of Example 17, the following compounds were synthesized:

[0193]

[0194]

[0195] Example 22: 2-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-4-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (Compound 22)

[0196]

[0197] Step 1: Preparation of (1S,3S)-3-((5-aminopyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (22a)

[0198] At room temperature, tert-butyl (1S,3S)-3-((5-aminopyridin-2-yl)amino)cyclopentyl)carbamate (14b) (0.62 g, 2.11 mmol), methyl 5-(bromomethyl)-2-chloroisonicotinic acid (0.56 g, 2.10 mmol), and potassium carbonate (0.87 g, 6.32 mmol) were dispersed in DMF (8 mL), and the mixture was reacted at 25 °C for 1 hour to terminate the reaction. After the reaction was completed, the mixture was extracted with a dichloromethane:methanol (10:1) mixture, concentrated, and the crude product was purified by silica gel column chromatography (eluent: ethyl acetate:petroleum ether = 0%-90%) to give the target compound (1S,3S)-3-(5-(4-chloro-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-ylamino)cyclopentyl)carbamate (22a).

[0199] LCMS(ESI)calcd for C 22 H 26 ClN5O3[M+H] + m / z 444, found 443.9.

[0200] 1 H NMR (400MHz, CDCl3) δ8.62(d,J=4.8Hz,1H),8.33(d,J=2.4Hz,1H),8.05(dd,J=9.2,2.4Hz,1H),7.74(d,J=4.8Hz,1H),6.52(d,J=9.2Hz,1H),5.17(br s,1H),4.83(s,2H),4.57(br s,1H),4.22–4.17(m,2H),2.28–2.18(m,2H),1.99–1.95(m,2H),1.60-1.50(m,2H),1.45(s,9H).

[0201] Step 2: Preparation of (1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (22b)

[0202] Under nitrogen protection at room temperature, tert-butyl carbamate (22a) (0.55 g, 1.24 mmol), 2,4,6-trimethyl-1,3,5,2,4,6-tricycloborane (0.16 g, 1.24 mmol), and potassium carbonate (0.43 g, 3.09 mmol) were dissolved in a mixture of 1,4-dioxane (20 mL) and water (5 mL). Palladium acetate (0.03 g, 0.12 mmol) and tricyclohexylphosphine tetrafluoroborate (0.05 g, 0.12 mmol) were then added. The mixture was reacted at 100 °C for 12 hours until the reaction was terminated. After the reaction was complete, the mixture was filtered, extracted, and concentrated. The crude product was purified by silica gel column chromatography (elution: methanol: dichloromethane = 0%-6%) to obtain the target compound (1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (22b).

[0203] LCMS(ESI)calcd for C 23 H 29 N5O3[M+H] + m / z 424, found 424.3.

[0204] 1 H NMR (400MHz, MeOD) δ8.63(d,J=5.2Hz,1H),8.37(d,J=2.4Hz,1H),7.86(dd,J=9.2,2.8Hz,1H),7.64(d,J=5.2Hz,1H),6.61(d,J=9.2Hz,1H ),4.99(s,2H),4.25–4.22(m,1H),4.10-4.03(m,1H),2.65(s,3H),2.16–2.11(m,2H),1.95–1.75(m,2H),1.56–1.50(m,2H),1.44(s,9H).

[0205] Step 3: Preparation of (2-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-4-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (22c)

[0206] (1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (22b) (0.33 g, 0.77 mmol) was dispersed in a 1,4-dioxane hydrochloric acid solution (4 mL, 4 M). The mixture was reacted at 25 °C for 2 hours to terminate the reaction. After the reaction was completed, the crude target compound (2-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-4-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one) (22c) was obtained by concentration. The product was used directly in the next step without further purification.

[0207] LCMS(ESI)calcd for C 18 H 21 N5O2[M+H] + m / z 324, found 324.1.

[0208] 1 H NMR (400MHz, MeOD) δ8.89(d,J=6.0Hz,1H),8.69(d,J=2.4Hz,1H),8.46(dd,J=9.6,2.4Hz,1H),8.19(d,J=6.0Hz,1H),7.25(d,J=9. 6Hz,1H),5.27(s,2H),4.48–4.34(m,1H),3.93–3.82(m,1H),2.91(s,3H),2.48–2.34(m,2H),2.29–2.18(m,2H),1.91–1.76(m,2H).

[0209] Step 4: Preparation of nitrogen-((1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)amino)cyclopentyl)cyanamide (22d)

[0210] At room temperature, (2-(6-(((1S,3S)-3-aminocyclopentyl)amino)pyridin-3-yl)-4-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (22c) (0.26 g, 1.61 mmol) was dispersed in a mixed solution of tetrahydrofuran (5 mL) and DMF (1 mL), and bromocyanide (0.13 g, 1.21 mmol) and N,N-diisopropylethylamine (0) were added. 0.21 g (1.61 mmol), the mixture was reacted at 25 °C for 12 hours to terminate the reaction. After the reaction was completed, the mixture was filtered and concentrated. The crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 0%-5%) to give the target compound N-((1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)amino)cyclopentyl)cyanamide (22d).

[0211] 1 H NMR (400MHz, MeOD) δ8.63(d,J=5.2Hz,1H),8.38(d,J=2.0Hz,1H),7.87(dd,J=9.2,2.8Hz,1H),7.64(d,J=5.2Hz,1H),6.61(d,J=9.2Hz,1H),4.9 9(s,2H),4.40–4.29(m,1H),3.86–3.77(m,1H),2.31-2.22(m,1H),2.17 -2.06(m,2H),1.90-1.84(m,1H),1.74-1.64(m,1H),1.62-1.54(m,1H).

[0212] Step 5: Preparation of (E)-2-hydroxy-1-((1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-ylamino)cyclopentyl)guanidine (22e)

[0213] Under nitrogen atmosphere at room temperature, N-((1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)amino)cyclopentyl)cyanamide (22d) (0.16 g, 0.45 mmol) was dispersed in ethanol (4 mL), followed by the addition of triethylamine (0.1 mL) and hydroxylamine hydrochloride (0.06 g, 0.91 mmol). The mixture was reacted at 60 °C for 2 hours until the reaction was terminated. After the reaction was completed, the crude product (E)-2-hydroxy-1-((1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-ylamino)cyclopentyl)guanidine (22e) was obtained. The product was used directly in the next step without further purification.

[0214] LCMS(ESI)calcd for C 19 H 23 N7O2[M+H] + m / z 382, ​​found 381.9.

[0215] Step 6: Preparation of 2-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-4-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (compound 22)

[0216] At room temperature, (E)-2-hydroxy-1-((1S,3S)-3-(5-(4-methyl-1-oxo-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)pyridin-2-ylamino)cyclopentyl)guanidine (22e) (0.18 g, 0.47 mmol) and 2,5-dioxopyrrolidone-1-ylcyclopropane carboxylate (0.10 g, 0.52 mmol) were dispersed in N-methylpyrrolidone (4 mL). The mixture was reacted at 25 °C for 2 hours, and then the reaction was terminated by heating to 60 °C for 14 hours. After the reaction was completed, the target product 2-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-4-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (compound 22) was prepared by high performance liquid chromatography (0.05% ammonia-acetonitrile system, 15%-85%, 20 mL / min).

[0217] LCMS(ESI)calcd for C 23 H 25 N7O2[M+H] + m / z 432, found 432.1.

[0218] 1H NMR (400MHz, DMSO-d6) δ8.64(d,J=4.8Hz,1H),8.37(d,J=2.4Hz,1H),7.86(dd,J=9.2,2.4Hz ,1H),7.55(d,J=4.8Hz,1H),6.81(d,J=6.8Hz,1H),6.70(d,J=6.8Hz,1H),6.54(d,J=9.2Hz, 1H),4.99(s,2H),4.28–4.23(m,1H),3.86–3.82(m,1H),2.57(s,3H),2.14–2.03(m,3H),1.9 6–1.88(m,1H),1.83–1.75(m,1H),1.53–1.42(m,2H),1.18–1.10(m,2H),1.02–0.95(m,2H).

[0219] Example 23: 2-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-6-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (Compound 23)

[0220]

[0221] Following the synthetic route of Example 22, the target product 2-(6-((1S,3S)-3-((5-cyclopropyl-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-6-methyl-2,3-dihydro-1H-pyrrolo[3,4-c]pyridin-1-one (compound 23) was obtained.

[0222] LCMS(ESI)calcd for C 23 H 25 N7O2[M+H] + m / z 432, found 432.1.

[0223] 1H NMR (400MHz, DMSO-d6) δ8.80 (s, 1H), 8.34 (d, J = 2.4Hz, 1H), 7.85 (dd, J = 9.2, 2.8Hz, 1H) ,7.59(s,1H),6.79(d,J=6.8Hz,1H),6.68(d,J=6.8Hz,1H),6.53(d,J=9.2Hz,1H),4.97 (s,2H),4.28–4.23(m,1H),3.85–3.82(m,1H),2.60(s,3H),2.15–2.03(m,3H),1.95–1. 87(m,1H),1.84–1.75(m,1H),1.54–1.42(m,2H),1.16–1.09(m,2H),1.02–0.94(m,2H).

[0224] Referring to the synthetic schemes of Examples 22 and 23, the following compounds were synthesized:

[0225]

[0226]

[0227]

[0228] Example 24: 6-(5-fluoro-6-(((1S,3S)-3-((5-(((1S,2R)-2-fluorocyclopropyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (Compound 24)

[0229]

[0230] Step 1: Preparation of ((1S,3S)-3-((5-bromo-3-fluoropyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (24a)

[0231] Under nitrogen protection at 25°C, 5-bromo-2,3-difluoropyridine (1.00 g, 5.20 mmol), ((1S,3S)-3-aminocyclopentyl)carbamate tert-butyl ester (1a) (0.52 g, 2.60 mmol), and N,N-diisopropylethylamine (1.34 g, 10.40 mmol) were dissolved in dimethyl sulfoxide (10 mL). The reaction was terminated at 100°C for 16 hours. The reaction solution was cooled to room temperature, extracted, and concentrated. The crude product was purified by silica gel column chromatography (dichloromethane:methanol = 20:1) to obtain the target compound ((1S,3S)-3-((5-bromo-3-fluoropyridine-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (24a).

[0232] 1 H NMR (400MHz, DMSO-d6) δ7.91(d,J=2.0Hz,1H),7.64(dd,J=10.8,2.0Hz,1H),6.88(d,J=7.2Hz,1H),6.79(d,J =6.6Hz,1H),4.35–4.30(m,1H),3.95–3.90(m,1H),2.07–1.89(m,2H),1.85–1.70(m,2H),1.53–1.38(m,11H).

[0233] Step 2: Preparation of ((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (24b)

[0234] Under nitrogen protection at 25°C, 5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (0.50 g, 3.73 mmol), ((1S,3S)-3-((5-bromo-3-fluoropyridin-2-yl)amino)cyclopentyl)carbamate tert-butyl ester (24a) (2.10 g, 5.59 mmol), cesium carbonate (3.64 g, 11.18 mmol), cuprous iodide (0.71 g, 3.73 mmol), and N,N'-dimethyl-1,2-cyclohexanediamine (0.53 g, 3.73 mmol) were dissolved in a 20 mL solution of dioxane. The reaction was terminated at 120°C for 2 hours. The reaction solution was cooled to room temperature, filtered, extracted, and concentrated. The crude product was purified by silica gel column chromatography (dichloromethane:methanol = 20:1) to obtain the target compound ((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)tert-butyl carbamate (24b).

[0235] 1H NMR (400MHz, DMSO-d6) δ8.81–8.72(m,1H),8.24(d,J=2.0Hz,1H),8.12(d,J=6.8Hz ,1H),8.02(dd,J=13.2,2.4Hz,1H),7.63(dd,J=7.6,4.8Hz,1H),6.90(d,J=7.2Hz,1 H),6.62(d,J=6.8Hz,1H),4.96(s,2H),4.45–4.36(m,1H),3.98–3.93(m,1H),2.13– 2.02(m,1H),2.00–1.93(m,1H),1.86–1.74(m,2H),1.56–1.41(m,2H),1.38(s,9H).

[0236] Step 3: Preparation of 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)-5-fluoropyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (24c)

[0237] At 25°C, tert-butyl carbamate (24b) (0.98 g, 2.29 mmol) was dissolved in a mixture of hydrochloric acid / dioxane (10 mL, 4 M) and methanol (10 mL). The reaction was terminated at 25°C for 16 hours. The target compound 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)-5-fluoropyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (24c) was obtained by concentration.

[0238] 1 H NMR (400MHz, DMSO-d6) δ8.79(d,J=4.4Hz,1H),8.32(d,J=2.2Hz,1H),8.23–8.15(m,5H),7.67(dd,J=7. 6,4.8Hz,1H),5.01(s,2H),4.63-4.49(m,1H),3.75–3.60(m,1H),2.13–2.02(m,4H),1.72–1.58(m,2H).

[0239] Step 4: Preparation of N-((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (24d)

[0240] Under nitrogen protection at 25°C, 6-(6-(((1S,3S)-3-aminocyclopentyl)amino)-5-fluoropyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (24c) (1.00 g, 2.30 mmol), cyanogen bromide (0.27 g, 2.50 mmol), and sodium carbonate (1.11 g, 10.50 mmol) were dissolved together in 20 mL of methanol. The reaction was terminated at 25°C for 1 hour. Extraction, drying, filtration, and concentration were then performed. The crude product was purified by silica gel column chromatography (dichloromethane:methanol = 10:1) to obtain the target compound N-((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (24d).

[0241] LCMS(ESI)calcd for C 18 H 17 FN6O[M+H]+m / z 353.15,found 353.31.

[0242] Step 5: Preparation of 1-((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)-2-hydroxyguanidine (24e)

[0243] Under nitrogen protection at 25°C, N-((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)cyanamide (24d) (0.40 g, 1.10 mmol), hydroxylamine hydrochloride (0.20 g, 2.84 mmol), and triethylamine (0.46 g, 4.54 mmol) were dissolved in 10 mL of ethanol. The reaction was terminated at 80°C for 1 hour. The reaction solution was cooled to room temperature and concentrated to obtain the target compound 1-((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)-2-hydroxyguanidine (24e), which was directly used in the next step.

[0244] LCMS(ESI)calcd for C 18 H 20 FN7O2[M+H] + m / z 386.18, found 386.20.

[0245] Step 6: Preparation of 6-(5-fluoro-6-(((1S,3S)-3-((5-(((1S,2R)-2-fluorocyclopropyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 24)

[0246] Under nitrogen protection at 25°C, 1-((1S,3S)-3-((3-fluoro-5-(7-oxo-5,7-dihydro-6H-pyrrolo[3,4-b]pyridin-6-yl)pyridin-2-yl)amino)cyclopentyl)-2-hydroxyguanidine (24e) (0.15 g, 0.23 mmol) and 2,5-dioxopyrrolidine-1-yl(1S,2R)-2-fluorocyclopropane-1-carboxylic acid ester (0.09 g, 0.47 mmol) were dissolved together in a solution of N-methylpyrrolidone (3 mL). The reaction was terminated at 80°C for 16 hours. The reaction solution was cooled to room temperature, extracted, filtered, dried, and concentrated. The crude product was purified by high performance liquid chromatography (C18, 0.1% formic acid-acetonitrile system, 15%-85%, 20 mL / min) to obtain the target compound 6-(5-fluoro-6-(((1S,3S)-3-((5-(((1S,2R)-2-fluorocyclopropyl)-1,2,4-oxadiazol-3-yl)amino)cyclopentyl)amino)pyridin-3-yl)-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (compound 24). LCMS(ESI)calcd for C 22 H 21 F2N7O2[M+H] + m / z 454.18, found454.15.

[0247] 1 H NMR(400MHz, DMSO-d6)δ8.76(dd,J=4.8,1.2Hz,1H),8.24(d,J=2.0Hz,1H),8.18–8.08(m,1H),8 .02(dd,J=13.2,2.0Hz,1H),7.63(dd,J=7.6,4.8Hz,1H),6.89(d,J=6.8Hz,1H),6.65(d,J=6.4H z,1H),5.20–5.02(m,1H),4.96(s,2H),4.50–4.41(m,1H),3.97–3.80(m,1H),2.80–2.69(m,1H) ,2.18–2.02(m,2H),2.00–1.85(m,2H),1.84–1.73(m,1H),1.62–1.45(m,2H),1.42–1.31(m,1H).

[0248] Referring to the synthesis scheme of Example 24, the following compounds were synthesized:

[0249]

[0250]

[0251] Compound Example 22 in patent WO2024078620A1 is reference compound A, and the structure of compound A is as follows:

[0252] Example 238 of patent CN119264042A is reference compound B, and the structure of compound B is as follows:

[0253] To illustrate the beneficial effects of the present invention, the following experimental examples are provided.

[0254] Experimental Example 1: Compound Binding Assay with PCSK9 Protein

[0255] Experimental objective: To evaluate the binding affinity of the compound to the PCSK9 protein.

[0256] Experimental plan:

[0257] 1. Test materials

[0258] 1) PBS, 2) PCSK9 protein, 3) SAchip, 4) HBSP, 5) NaOH, 6) CaCl₂ 2， 7) DMSO, 8) Isopropanol

[0259] 2. Test methods

[0260] Protein fixation:

[0261] 1) The PCSK9 protein is immobilized onto the SA chip via biotin-SA tag capture, and the channel is closed after immobilization.

[0262] 2) The final RU is 8300 and Rmax is 51.34RU.

[0263] 3) Prepare a 10 mM stock solution of the compound using DMSO, and use the prepared analytical buffer (HBSP + 0.1 mM CaCl₂) to test the compound. 2， Dilute with 4% DMSO (pH 7.4) and filter through a 0.22 μm filter membrane. Starting from 1000 nM, perform 3-fold serial dilutions and test 8 non-zero concentration points, i.e., the final test concentrations are 1000.00, 333.33, 111.11, 37.04, 12.35, 4.12, 1.37, and 0.46 nM.

[0264] 4. The final binding and dissociation curves were obtained by subtracting the reference channel and buffer blank control from the experimental channel signal values. The affinity data were obtained by fitting the curves according to the 1:1 binding mode kinetic method. The inhibitor AZD-0780 (Cas: 2455427-91-3) was used as the reference compound.

[0265] Table 1. Affinity data of some compounds with PCSK9 protein.

[0266]

[0267] Experimental conclusion: The compound described in this invention has a good binding effect on PCSK9 protein.

[0268] Experimental Example 2: Effect of Compounds on the Concentration of PCSK9 Secreted by HepG2 Cells

[0269] Experimental objective: To evaluate the inhibitory effect of the compound on PCSK9.

[0270] Experimental plan:

[0271] 1. Test materials

[0272] 1) HepG2 cells, 2) MEM culture medium, 3) Penicillin and streptomycin, 4) PBS, 5) Fetal bovine serum, 6) TrypLE, 7) DMSO 2. Experimental Methods

[0273] 1) Seed HepG2 cells into 96-well plates at 25,000 cells / 200 μL per well and incubate the cell culture plates at 37°C in a 5% CO2 incubator for 24 h.

[0274] 2) Prepare stock solutions of the positive control compound and the test compound using DMSO at a concentration of 100 mM. Dilute the positive control compound and the test compound, add them to cell culture plates, and incubate the cell culture plates in a 37°C, 5% CO2 incubator for 48 h. Use the inhibitor AZD-0780 (Cas: 2455427-91-3) as the positive control compound.

[0275] 3) Collect 100 μL of cell culture supernatant as a test sample.

[0276] 4) Dilute the test sample and standard with AlphaLISA test buffer and add them to the test plate. Then add the mixture of AlphaLISA Anti-PCSK9 Acceptor beads and Biotinylated Antibody Anti-PCSK9 to the test plate and incubate at 23°C for 1 hour. After that, add Streptavidin (SA)-coated Donor beads to the test plate and incubate at 23°C for 0.5 hours. Then read the AlphaLISA data using Envision.

[0277] 5) The formula for calculating the %PCSK9 secretion ratio is as follows: %PCSK9 secretion ratio relative to control wells = counts of test compounds / counts of average control wells * 100%

[0278] Experimental Results: Table 2 shows the ability of some compounds in this scheme to inhibit PCSK9 function using the above assay method:

[0279] Table 2 shows the ability of some compounds to inhibit PCSK9.

[0280]

[0281] Experimental Conclusion: The compound described in this invention has a good inhibitory effect on PCSK9 secreted by HepG2 cells. Experimental Example 3: Effect of the Compound on the Concentration of LDL-R Secreted by HepG2 Cells. Experimental Objective: To evaluate the inhibitory effect of the compound on LDL-R.

[0282] Experimental protocol:

[0283] 1. Experimental materials:

[0284] 1) HepG2 cells, 2) MEM medium, 3) Penicillin-streptomycin, 4) Low-fat FBS, 5) FBS, 6) Human LDL-RElisa kit, 7) PBS, 8) TrypLE digestive enzyme, 9) DMSO

[0285] 2. Test method:

[0286] 1) HepG2 cells were seeded into 96-well plates and cultured overnight in a 37°C, 5% CO2 incubator with medium containing low-fat FBS.

[0287] 2) Prepare stock solutions of the positive control compound and the test compound using DMSO. Add PCSK9 protein, the positive control compound, or the test compound to the cell culture medium. The final concentration of PCSK9 is 2 μg / ml, the final concentration of the positive control compound is 300 μM, and the final concentrations of the test compounds are 25 and 50 μM. Incubate the cells at 37°C in a 5% CO2 incubator for 48 h.

[0288] 3) After cell lysis, collect the supernatant and dilute human LDL-R with diluent RD5-25 for plotting a standard curve. Prepare human LDL-R well plates, add diluent RD1-64 to each well, add the diluted test sample and standard to the well plates, incubate at room temperature for 2 hours, and then wash the well plates 4 times with 1X Wash Buffer. Then add the human LDL-R conjugate, incubate at room temperature for 2 hours, and then wash the well plates 4 times with 1X Wash Buffer. Mix equal volumes of Reagent A and Reagent B and add them to the well plates. Incubate in the dark for 30 minutes, then add the stop solution to terminate the reaction. Measure the absorbance at 450 nm in each well, plot the curve based on the data, and calculate the LDL-R concentration in the sample.

[0289] 4) The calculation formula is as follows: LDL-R expression relative to the control group (%) = counts 测试化合物 / counts 对照孔平均值 -1*100%. Experimental results: Table 3 shows the effects of some compounds in this protocol on LDL-R secretion, as determined using the above assay method:

[0290] Table 3 shows the effects of some compounds on LDL-R secretion.

[0291]

[0292]

[0293] Experimental conclusion: Some of the compounds described in this invention have a significant effect on increasing LDL-R secreted by HepG2 cells.

[0294] Experimental Example 4: Pharmacokinetic Determination of Compounds in Mice

[0295] Experimental objective: Using C57BL / 6J mice as test animals, to study the pharmacokinetic characteristics of the compound of this invention when administered orally in mice.

[0296] Test Plan

[0297] Laboratory animals:

[0298] C57BL / 6J mice, male, purchased from Spifort (Suzhou) Biotechnology Co., Ltd., Animal Production License No. (SCXK(Su)2022-0006).

[0299] Experiment content:

[0300] Weigh 0.6 mg of the test compound 2 and dissolve it in 0.5% MC solution. Stir and sonicate until homogeneous. The concentration is 0.5 mg / mL.

[0301] Administration:

[0302] Mice were fasted overnight but given free access to water.

[0303] Three C57BL / 6J mice were fasted overnight and then administered the drug PO at a dose of 5 mg / kg, with a volume of 10 mL / kg. Sample collection: Blood samples of 0.05 mL were collected from the orbital venous plexus before and at 0.25, 0.5, 1, 2, 4, 8, and 24 hours after drug administration. The samples were anticoagulated with EDTA-K2, centrifuged at 3500 rpm for 10 min at 4°C, and then transferred to EP tubes for immediate storage at -20°C until analysis. Feeding was resumed 4 hours after drug administration.

[0304] Results: A standard curve was established using the internal standard method, with the theoretical standard curve concentration on the x-axis and the peak area ratio (peak area of ​​test compound / peak area of ​​internal standard) on the y-axis. Linear regression (weighting factor 1 / X2) was used, with R² > 0.9900. Unknown samples were calculated using the standard curve. Pharmacokinetic parameters, including T1 / 2, Tmax, Cmax, and AUC, were calculated using a non-compartmental analysis model in WinNonlin 8.2 software. The experimental results are shown in Table 4 below. The inhibitor AZD-0780 (Cas: 2455427-91-3) was used as the reference compound.

[0305] Table 4. Pharmacokinetic parameters of some compounds in mice.

[0306]

[0307] Experimental conclusion: The compound described in this invention has better pharmacokinetic advantages than the reference compound.

[0308] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A compound of Formula I, or a stereoisomer thereof, or a pharmaceutically acceptable salt or prodrug thereof: Where L 1 L 2 L 3 and L 4 Each is independently selected from: CH or N, and L 1 L 2 L 3 and L 4 No more than two of them are selected from N, and the rest are CH; R 1 Selected from: isopropyl, C 1-3 Halogenated alkyl or C 3-5 cycloalkyl; wherein the C 3-5 Each cycloalkyl group may optionally be substituted with one or more of the following substituents: hydrogen, halogen, halogenated C. 1-6 Alkyl or C 1-6 alkyl; R 2 Selected from: hydrogen or halogen; R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl, C 1-3 Alkoxy or C 1-3 Halogenated alkyl groups; X is selected from O or S.

2. The compound according to claim 1, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, The compound described in Formula I is represented by Formula I-1: Where L 1 L 2 L 3 and L 4 Each is independently selected from: CH or N, and L 1 L 2 L 3 and L 4 No more than two of them are selected from N, and the rest are CH; R 1 Selected from: isopropyl, C 1-3 Halogenated alkyl or C 3-5 cycloalkyl; wherein the C 3-5 Each cycloalkyl group may optionally be substituted with one or more of the following substituents: hydrogen, halogen, halogenated C. 1-6 Alkyl or C 1-6 alkyl; R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl, C 1-3 Alkoxy or C 1-3 Halogenated alkyl groups.

3. The compound according to claim 1 or 2, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, L 1 L 2 L 3 and L 4 Composition Selected from:

4. The compound according to claim 1, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, The compound described in Formula I is represented by Formula I-2: X is selected from O or S; R 1’ Selected from: halogen or C 1-6 Alkyl, wherein the C 1-6 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; R 2 Selected from: hydrogen or halogen; L 1 L 2 L 3 and L 4 Each is independently selected from: CH or N, and L 1 L 2 L 3 and L 4 No more than two of them are selected from N, and the rest are CH; R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl or C 1-3 Alkoxy, wherein the C 1-3 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; n is independently selected from 0, 1, or 2.

5. The compound according to claim 4, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, The compound described in Formula I-2 is represented by Formula I-2-1: R 1’ Selected from: Fluorine or C 1-3 Alkyl, wherein the C 1-3 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; n is independently selected from 0, 1, or 2.

6. The compound according to claim 4, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, The compound described in Formula I-2 is represented by Formula I-2-2: R 1’ Selected from: Fluorine or C 1-3 Alkyl, wherein the C 1-3 The alkyl group is optionally substituted with one or more of the following substituents: hydrogen or halogen; n is independently selected from 0, 1, or 2.

7. The compound according to claim 5 or 6, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, R 1’ Selected from: fluorine, methyl or trifluoromethyl; n is independently selected from 0, 1 or 2.

8. The compound according to claim 5 or 6, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, Selected from:

9. The compound according to claim 4, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, L 1 L 2 L 3 and L 4 Composition Selected from: R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl or C 1-3 Alkoxy, wherein the C 1-3 The alkyl group may optionally be substituted with one or more of the following substituents: hydrogen or halogen.

10. The compound according to claim 9, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, R 3 Selected from: hydrogen, halogen, cyano, C 1-3 Alkyl, C 1-3 Alkoxy or C 1-3 Halogenated alkyl groups.

11. The compound according to claim 10, or its stereoisomer, or its pharmaceutically acceptable salt, characterized in that, R 3 Selected from: hydrogen, fluorine, chlorine, cyano, methyl, methoxy, difluoromethyl, or trifluoromethyl.

12. The compound according to any one of claims 1-11, or its stereoisomer, or its pharmaceutically acceptable salt, wherein the compound is selected from any one of the following compounds:

13. A pharmaceutical composition, wherein, It includes the compound, stereoisomer or pharmaceutically acceptable salt thereof of any one of claims 1-12, and one or more pharmaceutically acceptable carriers, diluents or excipients.

14. Use of the compound of any one of claims 1-13 or a pharmaceutically acceptable salt thereof, its solvate, metabolite, cocrystal or prodrug, or the aforementioned composition in the preparation of a medicament for the treatment / prevention of PCSK9-mediated diseases.

15. The use according to claim 14, wherein the disease is hyperlipidemia.

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