A compound targeting degradation of CDK4 protein and preparation method and application thereof

Abstract

The application discloses a compound for targeted degradation of CDK4 protein, and a preparation method and application thereof, and relates to the field of medicine, in particular to a compound represented by formula (S) for targeted degradation of CDK4 protein, and a preparation method and application thereof.

Description

Technical Field

[0001] This invention relates to compounds, their preparation methods, and applications; specifically, it relates to a compound that targets and degrades CDK4 protein, its preparation method, and its applications. Background Technology

[0002] Cyclin-dependent kinases (CDKs) play a crucial role in cell proliferation by regulating cell cycle progression. During the G1 phase, CDK4 binds to cyclin D, phosphorylates Rb protein, and releases the transcription factor E2F, promoting the transition from G1 to S phase and thus driving cell proliferation. Dysregulation of cell cycle mechanisms is a significant driver of tumorigenesis; therefore, CDK4 has become an ideal target for cancer therapy. The applicant has designed a series of CDK4-targeting protein degradation chimeras (PROTACs) that can directly degrade CDK4 protein, thereby generating significant anti-cancer activity. Summary of the Invention

[0003] Objectives of the invention: This invention provides a compound with high anticancer activity that targets and degrades CDK4 protein; another objective of this invention is to provide a method for preparing the compound that targets and degrades CDK4 protein; yet another objective of this invention is to provide an application of the compound that targets and degrades CDK4 protein.

[0004] Technical solution: This invention provides a compound for targeting and degrading CDK4 protein, or a pharmaceutically acceptable salt thereof, the structure of which is shown in general formula (S):

[0005]

[0006] (S)

[0007] In the formula, linker is a linking group, which represents a straight or branched alkylene chain with a total length of 1-20 atoms, wherein the straight or branched alkylene chain is optionally interrupted once or more by one or more -O-, -CO-, -CONH-, -NH-, or any combination thereof.

[0008] The "multiple" refers to 2-10 items, for example, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The "repeated times" refers to 2-10 times, for example, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, or 10 times.

[0009] Furthermore, the linker is selected from the following structure: -(CH2) m -NH-, m = 1-8; -(CH2CH2O) n-CH2CH2NH-, n = 1-8; -(CH2) p -CONH-, p = 1-12; preferably, m = 1, 2, 3, 4, 5, 6, 7, 8, n = 1, 2, 3, 4, 5, 6, 7, 8, p = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12.

[0010] Furthermore, the linker is selected from the following structure: -(CH2) m -NH-, m = 3-6; -(CH2CH2O) n -CH2CH2NH-, n = 1-4; -(CH2) p -CONH-, p = 1-10.

[0011] Furthermore, the compound is selected from S-1 to S-18:

[0012]

[0013]

[0014]

[0015] Furthermore, the pharmaceutically acceptable salts mentioned above are acid addition salts of compounds of general formula (S), wherein the acid used for salt formation is selected from inorganic acids and organic acids, wherein the inorganic acid is selected from hydrochloric acid, sulfuric acid, and phosphoric acid, and the organic acid is selected from acetic acid, propionic acid, butyric acid, maleic acid, p-toluenesulfonic acid, malic acid, methanesulfonic acid, malonic acid, trichloroacetic acid, trifluoroacetic acid, fumaric acid, citric acid, diacid, camphoric acid, cinnamic acid, aspartic acid, and tartaric acid.

[0016] On the other hand, the present invention provides a method for preparing a compound that targets and degrades CDK4 protein or a pharmaceutically acceptable salt thereof, comprising the following steps:

[0017] Method 1:

[0018]

[0019] Compounds A and B were dissolved in N,N-dimethylformamide, and N,N-diisopropylethylamine was added. After the reaction was complete, the final product S was obtained by rapid silica gel column purification.

[0020] R1 is selected from: -(CH2) m -NH2, m = 3-6; -(CH2CH2O) n -CH2CH2NH2, n = 1-4.

[0021] Method 2:

[0022]

[0023] Compounds C and D were dissolved in N,N-dimethylformamide, and N,N-diisopropylethylamine was added. After the reaction was complete, the final product S was obtained by rapid silica gel column purification.

[0024] Where p = 1-10.

[0025] The present invention provides a pharmaceutical composition comprising a compound of general formula (S) or a pharmaceutically acceptable salt thereof or an isomer thereof, and a pharmaceutically acceptable carrier.

[0026] Furthermore, the dosage form of the drug is selected from at least one of tablets, capsules, granules, injections, powder for injection, eye drops, powders, pills, transdermal patches, ointments, aerosols, emulsions, liniments, suppositories, films, controlled-release formulations, and nano-formulations.

[0027] Pharmaceutically acceptable carriers refer to excipients or diluents that do not cause significant irritation to the organism and do not interfere with the biological activity and properties of the compound being administered. Excipients include flavoring agents, antioxidants, aromatizers, solubilizers, emulsifiers, preservatives, binders, osmotic pressure regulators, disintegrants, colorants, fillers, lubricants, etc., while diluents include dextrin, starch, sucrose, physiological saline, lactose, etc.

[0028] On the other hand, the present invention provides the use of the above-described compounds or pharmaceutically acceptable salts thereof in the preparation of CDK4 degrading agent drugs. These CDK4 degrading agent drugs can be used to treat cancer or tumor-related diseases.

[0029] On the other hand, the present invention provides the use of the above-described compounds or pharmaceutically acceptable salts thereof in the preparation of medicaments for the prevention and / or treatment of cancer or tumor-related diseases. Cancer or tumor-related diseases include lung cancer, gastric cancer, prostate cancer, liver cancer, leukemia, breast cancer, ovarian cancer, testicular cancer, colon cancer, multiple myeloma, pancreatic cancer, melanoma, glioma, brain glioma, pituitary adenoma, various solid tumors, and hematologic malignancies.

[0030] The compound of general formula (S) or its pharmaceutically acceptable salt described in this invention has degradative activity against CDK4 protein and therapeutic effects on related malignant tumors.

[0031] Beneficial effects: Compared with the prior art, the compound prepared by this invention that targets and degrades CDK4 protein has CDK4 degradation activity and is expected to overcome the drug resistance problem of traditional CDK4 small molecule inhibitors. Detailed Implementation

[0032] The present invention will be further described below. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods. Unless otherwise specified, the experimental materials used in the following embodiments were all purchased from conventional biochemical reagent stores. The present application will now be described in detail with reference to specific embodiments.

[0033] I. Synthesis of intermediate reactants

[0034] (1) Synthesis of 6-acetyl-2-[(5-(1-(3-aminopropyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M2):

[0035]

[0036] Commercially available compound M1 (892 mg, 2 mmol) and N-Boc-3-aminopropyl bromide (476 mg, 2.2 mmol) were dissolved in N,N-dimethylformamide (10 mL), followed by the addition of N,N-diisopropylethylamine (774 mg, 6 mmol). The reaction was carried out at 90 °C for 6 h. After the reaction was complete, the solution was concentrated and purified by column chromatography to give M2-1 (664 mg, 55% yield) as a white solid. ESI-MS m / z: 604.4 [M + H] + . 1 H NMR (400 MHz, DMSO-d6) δ 10.28 (s, 1H), 9.00 (s, 1H), 8.24 (d, J = 2.4 Hz, 1H), 7.99 (d, J = 8.6 Hz, 1H), 7.72 (dd, J = 8.6, 2.5Hz, 1H), 6.85 (s, 1H), 5.89 – 5.80 (m, 1H), 2.99 – 2.94 (m, 3H), 2.43 (s,3H), 2.32 (s, 3H), 2.28 – 2.24 (m, 3H), 2.03 – 1.96 (m, 2H), 1.91 – 1.86 (m,3H), 1.80 – 1.77 (m, 5H), 1.71 – 1.65 (m, 2H), 1.61 – 1.59 (m, 5H), 1.38 (s,9H).

[0037] Compound M2-1 (603 mg, 1 mmol) was dissolved in dichloromethane (5 mL), and 10 mL of 2N hydrogen chloride-ethyl acetate solution was added. The reaction was carried out at room temperature for 4 h. After the reaction was complete, the pH of the reaction solution was adjusted to neutral, and the solution was concentrated to obtain compound M2 directly as a white solid. ESI-MS m / z: 504.4 [M + H] + .

[0038] (2) Synthesis of 6-acetyl-2-[(5-(1-(4-aminobutyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M3):

[0039]

[0040] M3-1 was synthesized using the same method as M2-1. It was a white solid with a yield of 52%, and ESI-MS m / z: 618.4 [M+H]. + . 1 H NMR (400 MHz, DMSO-d6) δ 10.32 (s, 1H), 9.00 (s, 1H), 8.26 (d, J = 2.4Hz, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.72 (dd, J = 8.6, 2.5 Hz, 1H), 6.88 (t, J= 5.7 Hz, 1H), 5.84 (p, J = 8.9 Hz, 1H), 2.98 – 2.92 (m, 3H), 2.81 – 2.68 (m,2H), 2.67 – 2.57 (m, 2H), 2.43 (s, 3H), 2.33 (s, 3H), 2.30 – 2.22 (m, 2H), 2.00 – 1.86 (m, 6H), 1.85 – 1.75 (m, 4H), 1.68 – 1.50 (m, 6H), 1.38 (s, 9H).

[0041] M3 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 518.3 [M + H] + .

[0042] (3) Synthesis of 6-acetyl-2-[(5-(1-(5-aminopentyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M4):

[0043]

[0044] M4-1 was synthesized using the same method as M2-1. It was a white solid with a yield of 54%, and ESI-MS m / z: 632.4 [M+H]. + . 1 H NMR (400 MHz, DMSO-d6) δ 10.35 (s, 1H), 9.01 (s, 1H), 8.27 (s, 1H), 8.03 (d, J = 8.6 Hz, 1H), 7.72 (d, J = 8.6 Hz, 1H), 6.82 (t, J = 5.9 Hz, 1H),5.86 (q, J = 8.8 Hz, 1H), 3.46 – 3.20 (m, 6H), 2.95 – 2.91 (m, 3H), 2.43 (s,3H), 2.33 (s, 3H), 2.29 – 2.25 (m, 2H), 1.99 – 1.89 (m, 6H), 1.87 – 1.76 (m,4H), 1.65 – 1.57 (m, 6H), 1.39 (s, 9H).

[0045] M4 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 532.3 [M + H] + .

[0046] (4) Synthesis of 6-acetyl-2-[(5-(1-(6-aminohexyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M5):

[0047]

[0048] M5-1 was synthesized using the same method as M2-1. It was a white solid with a yield of 53%. ESI-MS m / z: 646.4 [M+H] + . 1H NMR (400 MHz, DMSO-d6) δ 10.32 (s, 1H), 9.00 (s, 1H), 8.26 (d, J = 2.4Hz, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.72 (dd, J = 8.6, 2.4 Hz, 1H), 6.78 (t, J= 5.7 Hz, 1H), 5.85 (p, J = 8.9 Hz, 1H), 3.46 – 3.17 (m, 6H), 2.94 – 2.89 (m,3H), 2.43 (s, 3H), 2.33 (s, 3H), 2.31 – 2.24 (m, 2H), 1.91 – 1.78 (m, 8H), 1.63 – 1.54 (m, 4H), 1.38 (s, 9H), 1.30 – 1.23 (m, 6H).

[0049] M5 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 546.3 [M + H] + .

[0050] (5) Synthesis of 6-acetyl-2-[(5-(1-(2-(2-aminoethoxy)ethyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M6):

[0051]

[0052] M6-1 was synthesized using the same method as M2-1. It was a white solid with a yield of 51%, and ESI-MS m / z: 634.4 [M+H]. + . 1H NMR (400 MHz, DMSO-d6) δ 10.34 (s, 1H), 9.01 (s, 1H), 8.26 (d, J = 2.4Hz, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.72 (d, J = 8.9 Hz, 1H), 6.86 (t, 1H),5.85 (p, J = 8.8 Hz, 1H), 3.46 – 3.43 (m, 2H), 3.38 – 3.31 (m, 4H), 3.13 –3.12 (m, 4H), 2.90 (s, 2H), 2.73 (s, 2H), 2.43 (s, 3H), 2.33 (s, 3H), 2.27 –2.25 (m, 2H), 1.94 – 1.89 (m, 4H), 1.81 – 1.77 (m, 2H), 1.62 – 1.59 (m, 2H), 1.38 (s, 9H).

[0053] M6 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 534.3 [M + H] + .

[0054] (6) Synthesis of 6-acetyl-2-[(5-(1-(2-(2-(2-aminoethoxy)ethoxy)ethyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M7):

[0055]

[0056] M7-1 was synthesized using the same method as M2-1. It was a white solid with a yield of 50%, and ESI-MS m / z: 678.4 [M+H]. + . 1H NMR (400 MHz, DMSO-d6) δ 10.32 (s, 1H), 9.01 (s, 1H), 8.26 (d, J = 2.4Hz, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.73 (dd, J = 8.6, 2.4 Hz, 1H), 6.77 (t, J= 5.7 Hz, 1H), 5.85 (p, J = 8.9 Hz, 1H), 3.70 – 3.66 (m, 2H), 3.58 – 3.52 (m,6H), 3.42 – 3.35 (m, 4H), 3.10 – 3.06 (m, 2H), 2.43 (s, 3H), 2.33 (s, 3H), 2.29 – 2.22 (m, 2H), 1.99 – 1.87 (m, 6H), 1.86 – 1.70 (m, 4H), 1.65 – 1.57(m, 2H), 1.37 (s, 9H).

[0057] M7 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 578.3 [M + H] + .

[0058] (7) Synthesis of 6-acetyl-2-[(5-(1-(2-(2-(2-(2-aminoethoxy)ethoxy)ethoxy)ethyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidine-7(8H)-one (M8):

[0059]

[0060] M8-1 was synthesized using the same method as M2-1. It was a white solid with a yield of 55%, and ESI-MS m / z: 722.4 [M+H]. + . 1H NMR (400 MHz, DMSO-d6) δ 10.34 (s, 1H), 9.01 (s, 1H), 8.27 (d, J = 2.4Hz, 1H), 8.03 (d, J = 8.6 Hz, 1H), 7.73 (dd, J = 8.6, 2.4 Hz, 1H), 6.77 (t, J= 5.8 Hz, 1H), 5.85 (p, J = 8.8 Hz, 1H), 3.79 – 3.71 (m, 2H), 3.61 – 3.56 (m,4H), 3.55 – 3.48 (m, 6H), 3.41 – 3.36 (m, 6H), 3.09 – 3.04 (m, 2H), 2.43 (s,3H), 2.33 (s, 3H), 2.28 – 2.24 (m, 2H), 1.94 – 1.91 (m, 6H), 1.83 – 1.76 (m,2H), 1.64 – 1.57 (m, 2H), 1.37 (s, 9H).

[0061] M8 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 622.4 [M + H] + .

[0062] (8) Synthesis of 6-acetyl-2-[(5-(1-(14-amino-3,6,9,12-tetraoxatetradecyl)piperidin-4-yl)pyridin-2-yl)amino]-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidin-7(8H)-one (M9):

[0063]

[0064] M9-1 was synthesized using the same method as M3. It was a white solid with a yield of 53% and ESI-MS m / z: 766.4 [M + H]. + . 1H NMR (400 MHz, DMSO-d6) δ 10.37 (s, 1H), 9.01 (s, 1H), 8.26 (d, 1H), 8.03 (d, J = 8.6 Hz, 1H), 7.72 (d, J = 8.6 Hz, 1H), 6.78 (t, J = 5.8 Hz, 1H),5.85 (p, J = 8.8 Hz, 1H), 3.80 – 3.71 (m, 2H), 3.62 – 3.55 (m, 6H), 3.54 –3.52 (m, 4H), 3.51 – 3.47 (m, 6H), 3.07 – 3.03 (m, 2H), 2.88 – 2.77 (m, 1H),2.43 (s, 3H), 2.33 (s, 3H), 2.29 – 2.24 (m, 2H), 1.97 – 1.86 (m, 6H), 1.83 –1.76 (m, 2H), 1.63 – 1.57 (m, 2H), 1.36 (s, 9H).

[0065] M9 was synthesized using the same method as M2. It is a white solid, ESI-MS m / z: 666.4 [M + H] + .

[0066] (9) Synthesis of 2-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)acetamide (M10):

[0067]

[0068] 4-Amino-2-(2,6-dioxadiazine-3-yl)isoindole-1,3-dione (476 mg, 2 mmol) was dissolved in N,N-dimethylformamide (10 mL), followed by the addition of N,N-diisopropylethylamine (774 mg, 6 mmol). Acetyl bromoacetyl chloride (346 mg, 2.2 mmol) was then added dropwise under ice bath conditions. After reacting for 10 min, the mixture was allowed to react at room temperature for 3 h. The solvent was removed by evaporation under reduced pressure, and the mixture was rapidly purified by silica gel column chromatography to give compound M10 (236 mg, 30% yield) as a pale yellow solid. ESI-MS m / z: 394.1 [M + H] + . 1H NMR (400 MHz, DMSO-d6) δ 11.16 (s, 1H), 10.27 (s, 1H), 8.47 (d, J = 8.4Hz, 1H), 7.87 (td, J = 7.9, 4.6 Hz, 1H), 7.66 (dd, J = 22.3, 7.3 Hz, 1H), 5.19 – 5.14 (m, 1H), 4.34 (s, 2H), 2.64 – 2.56 (m, 2H), 2.11 – 2.05 (m, 2H).

[0069] (10) Synthesis of 3-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)propionamide (M11):

[0070]

[0071] Following the synthesis method for M10, a pale yellow solid was obtained in 32% yield. ESI-MS m / z: 408.0 [M + H] + . 1 HNMR (400 MHz, DMSO-d6) δ 11.21 (s, 1H), 9.93 (d, J = 2.1 Hz, 1H), 8.48 (d, J= 8.4 Hz, 1H), 7.89 (t, J = 7.9 Hz, 1H), 7.68 (d, J = 7.3 Hz, 1H), 5.20 (dd,J = 12.8, 5.4 Hz, 1H), 3.79 (t, J = 6.3 Hz, 2H), 3.18 (t, J = 6.3 Hz, 2H), 2.70 – 2.54 (m, 4H).

[0072] (11) Synthesis of 4-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindole-4-yl)butyramide (M12):

[0073]

[0074] Following the synthesis method for M10, a pale yellow solid was obtained in 33% yield. ESI-MS m / z: 422.1 [M + H] + . 1HNMR (400 MHz, DMSO-d6) δ 11.17 (s, 1H), 9.81 (d, J = 2.0 Hz, 1H), 8.41 (d, J= 8.4 Hz, 1H), 7.84 (dd, J = 8.4, 7.3 Hz, 1H), 7.63 (d, J = 7.2 Hz, 1H), 5.16(dd, J = 12.7, 5.4 Hz, 1H), 3.62 (t, J = 6.7 Hz, 2H), 2.65 – 2.60 (m, 4H), 2.19 – 2.04 (m, 4H).

[0075] (12) Synthesis of 5-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)pentanamide (M13):

[0076]

[0077] Following the synthesis method for M10, a pale yellow solid was obtained in 31% yield. ESI-MS m / z: 436.1 [M + H] + . 1 HNMR (400 MHz, DMSO-d6) δ 11.16 (s, 1H), 9.74 (d, J = 6.3 Hz, 1H), 8.45 (d, J= 8.4 Hz, 1H), 7.84 (t, J = 7.9 Hz, 1H), 7.62 (d, J = 7.2 Hz, 1H), 5.15 (dd,J = 12.8, 5.4 Hz, 1H), 3.60 – 3.51 (m, 2H), 2.94 – 2.80 (m, 2H), 2.63 – 2.58(m, 2H), 1.90 – 1.72 (m, 6H).

[0078] (13) Synthesis of 6-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)hexanoamide (M14):

[0079]

[0080] Following the synthesis method for M10, a pale yellow solid was obtained in 35% yield. ESI-MS m / z: 451.1 [M + H] + . 1HNMR (400 MHz, DMSO-d6) δ 11.17 (s, 1H), 9.71 (s, 1H), 8.48 (d, J = 8.4 Hz,1H), 7.85 – 7.81 (m, 1H), 7.62 (d, J = 7.2 Hz, 1H), 5.16 (dd, J = 12.8, 5.4Hz, 1H), 3.53 – 3.51 (m, 2H), 2.72 – 2.64 (m, 1H), 2.61 – 2.52 (m, 2H), 2.28(t, J = 7.3 Hz, 2H), 2.13 – 2.01 (m, 1H), 1.85 – 1.82 (m, 2H), 1.68 – 1.64(m, 2H), 1.46 – 1.44(m, 2H).

[0081] (14) Synthesis of 7-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)heptamide (M15):

[0082]

[0083] Following the synthesis method for M10, a pale yellow solid was obtained in 37% yield. ESI-MS m / z: 464.1 [M + H] + . 1 HNMR (400 MHz, DMSO-d6) δ 11.18 (s, 1H), 9.70 (s, 1H), 8.48 (d, J = 8.4 Hz,1H), 7.87 – 7.79 (m, 1H), 7.61 (d, J = 7.2 Hz, 1H), 5.16 (dd, J = 12.7, 5.4Hz, 1H), 3.53 (t, J = 6.8 Hz, 2H), 2.92 – 2.87 (m, 1H), 2.63 – 2.53 (m, 2H), 2.48 (t, J = 7.4 Hz, 2H), 2.12 – 2.05 (m, 1H), 1.83 – 1.79 (m, 2H), 1.66 –1.62 (m, 2H), 1.43 – 1.36 (m, 4H).

[0084] (15) Synthesis of 8-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)octamide (M16):

[0085]

[0086] Following the synthesis method for M10, a pale yellow solid was obtained in 39% yield. ESI-MS m / z: 478.2 [M + H] + . 1 HNMR (400 MHz, DMSO-d6) δ 11.17 (s, 1H), 9.71 (s, 1H), 8.47 (d, J = 8.4 Hz,1H), 7.83 (dd, J = 8.4, 7.3 Hz, 1H), 7.62 (dd, J = 7.4, 0.8 Hz, 1H), 5.15(dd, J = 12.7, 5.4 Hz, 1H), 3.63 (t, J = 6.6 Hz, 1H), 3.53 (t, J = 6.7 Hz,1H), 2.95 – 2.85 (m, 1H), 2.64 – 2.52 (m, 2H), 2.47 (t, J = 7.4 Hz, 2H), 2.09– 2.03 (m, 1H), 1.83 – 1.68 (m, 2H), 1.64 – 1.59 (m, 2H), 1.42 – 1.31 (m,7H).

[0087] (16) Synthesis of 9-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)nonanoamide (M17):

[0088]

[0089] Following the synthesis method for M10, a pale yellow solid was obtained in 42% yield. ESI-MS m / z: 492.1 [M + H] + . 1HNMR (400 MHz, DMSO-d6) δ 11.17 (s, 1H), 9.70 (s, 1H), 8.47 (d, J = 8.4 Hz,1H), 7.83 (dd, J = 8.4, 7.3 Hz, 1H), 7.61 (dd, J = 7.3, 0.7 Hz, 1H), 5.15(dd, J = 12.8, 5.4 Hz, 1H), 3.62 (t, J = 6.6 Hz, 1H), 3.52 (t, J = 6.7 Hz,1H), 2.95 – 2.86 (m, 1H), 2.65 – 2.52 (m, 2H), 2.46 (t, J = 7.4 Hz, 2H), 2.11– 2.04 (m, 1H), 1.82 – 1.68 (m, 2H), 1.67 – 1.59 (m, 2H), 1.41 – 1.28 (m,8H).

[0090] (17) Synthesis of 10-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)decanoamide (M18):

[0091]

[0092] Following the synthesis method for M10, a pale yellow solid was obtained in 45% yield. ESI-MS m / z: 506.2 [M + H] + . 1 HNMR (400 MHz, Chloroform-d) δ 9.34 (s, 1H), 8.77 (d, J = 8.5 Hz, 1H), 8.09(s, 1H), 7.65 (dd, J = 8.5, 7.3 Hz, 1H), 7.48 (d, J = 7.3 Hz, 1H), 4.89 (dd,J = 12.2, 5.4 Hz, 1H), 3.46 (t, J = 6.7 Hz, 2H), 2.88 – 2.80 (m, 1H), 2.79 –2.65 (m, 2H), 2.39 (t, J = 7.5 Hz, 2H), 2.13 – 2.08 (m, 1H), 1.73 – 1.64 (m,4H), 1.39 – 1.32 (m, 5H), 1.30 – 1.23 (m, 5H).

[0093] (18) Synthesis of 11-bromo-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl)undecanoamide (M19):

[0094]

[0095] Following the synthesis method for M10, a pale yellow solid was obtained in 46% yield. ESI-MS m / z: 520.2 [M + H] + . 1 HNMR (400 MHz, Chloroform-d) δ 9.34 (s, 1H), 8.77 (d, J = 8.5 Hz, 1H), 8.18(s, 1H), 7.64 (t, J = 7.9 Hz, 1H), 7.48 (d, J = 7.3 Hz, 1H), 4.89 (dd, J =12.1, 5.4 Hz, 1H), 3.46 (t, J = 6.7 Hz, 2H), 2.85 (dd, J = 14.7, 3.8 Hz, 1H), 2.77 – 2.65 (m, 2H), 2.39 (t, J = 7.5 Hz, 2H), 2.13 – 2.08 (m, 1H), 1.72 –1.64 (m, 4H), 1.35 – 1.28 (m, 6H), 1.23 (s, 6H).

[0096] II. Synthesis of compounds S-1—S-18

[0097] Example 1: Synthesis of 4-[(3-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)propyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-1):

[0098]

[0099] M2 (503 mg, 1 mmol) and 2-(2,6-dioxadiazine-3-yl)-4-fluoroisoindole-1,3-dione (414 mg, 1.5 mmol) were dissolved in 10 mL of N,N-dimethylformamide, and N,N-diisopropylethylamine (387 mg, 3 mmol) was added. The mixture was reacted at 90 °C for 8 h. After the reaction was completed, the mixture was concentrated and column chromatography was used to obtain S-1, a yellow solid, with a yield of 50%. 1H NMR (400MHz, DMSO-d6) δ 11.09 (s, 1H), 10.13 (s, 1H), 9.00 (s, 1H), 8.31 (d, J = 2.4Hz, 1H), 7.99 (d, J = 8.5 Hz, 1H), 7.74 (dd, J = 8.7, 2.4 Hz, 1H), 7.60 (dd,J = 8.6, 7.0 Hz, 1H), 7.14 (d, J = 8.7 Hz, 1H), 7.03 (d, J = 7.0 Hz, 1H), 6.97 (d, J = 5.9 Hz, 1H), 5.85 (p, J = 8.9 Hz, 1H), 5.06 (dd, J = 12.9, 5.3Hz, 1H), 3.39 (d, J = 6.0 Hz, 3H), 3.04 – 2.91 (m, 2H), 2.89 – 2.54 (m, 4H), 2.43 (s, 3H), 2.33 (s, 3H), 2.27 – 2.01 (m, 4H), 1.99 – 1.91 (m, 4H), 1.84 –1.67 (m, 8H), 1.65 – 1.54 (m, 2H). HRMS (ESI) for C 41 H 45 N9O6(M + H) + : calcd760.3566; found, 760.3556.

[0100] Example 2: Synthesis of 4-[(4-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)butyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-2):

[0101]

[0102] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 52%. 1H NMR (400 MHz, DMSO-d6) δ 11.10(s, 1H), 10.33 (s, 1H), 9.00 (s, 1H), 8.25 (s, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.71 (d, J = 8.7 Hz, 1H), 7.60 (dd, J = 8.6, 7.0 Hz, 1H), 7.15 (d, J = 8.6Hz, 1H), 7.04 (d, J = 7.0 Hz, 1H), 6.64 (s, 1H), 5.84 (p, J = 8.9 Hz, 1H), 5.06 (dd, J = 12.9, 5.4 Hz, 1H), 3.51 (s, 1H), 2.94 – 2.84 (m, 2H), 2.74 –2.54 (m, 4H), 2.43 (s, 3H), 2.32 (s, 3H), 2.27 – 2.24 (m, 2H), 2.05 – 1.99(m, 2H), 1.95 – 1.86 (m, 4H), 1.85 – 1.70 (m, 4H), 1.67 – 1.58 (m, 4H), 1.30– 1.23 (m, 6H). HRMS (ESI) for C 42 H 47 N9O6(M + H) + : calcd 774.3722; found,774.3709.

[0103] Example 3: Synthesis of 4-[(5-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)pentyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-3):

[0104]

[0105] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 54%. 1H NMR (400 MHz, DMSO-d6) δ 11.10(s, 1H), 10.31 (s, 1H), 9.00 (s, 1H), 8.25 (d, J = 2.3 Hz, 1H), 8.01 (d, J =8.5 Hz, 1H), 7.73 – 7.70 (m, 1H), 7.59 (dd, J = 8.6, 7.0 Hz, 1H), 7.13 (d, J= 8.6 Hz, 1H), 7.03 (d, J = 7.0 Hz, 1H), 6.57 (t, J = 5.9 Hz, 1H), 5.83 (p, J= 9.0 Hz, 1H), 5.05 (dd, J = 12.9, 5.4 Hz, 1H), 3.51 (s, 1H), 2.92 – 2.84 (m,2H), 2.73 – 2.54 (m, 6H), 2.43 (s, 3H), 2.32 (s, 3H), 2.28 – 2.24 (m, 2H),1.91 – 1.84 (m, 6H), 1.80 – 1.78 (m, 2H), 1.70 – 1.58 (m, 6H), 1.53 – 1.37(m, 4H), 1.34 – 1.30 (m, 2H). HRMS (ESI) for C 43 H 49 N9O6(M + H) + : calcd788.3879; found, 788.3870.

[0106] Example 4: Synthesis of 4-[(6-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)hexyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-4):

[0107]

[0108] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 55%. 1H NMR (400 MHz, DMSO-d6) δ 11.10(s, 1H), 10.34 (s, 1H), 9.01 (s, 1H), 8.25 (s, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.70 (d, J = 9.0 Hz, 1H), 7.60 (dd, J = 8.5, 7.0 Hz, 1H), 7.13 (t, J = 7.8Hz, 1H), 7.03 (d, J = 7.0 Hz, 1H), 6.55 (t, J = 6.0 Hz, 1H), 5.84 (p, J = 8.9Hz, 1H), 5.06 (dd, J = 12.9, 5.4 Hz, 1H), 3.51 (s, 1H), 2.93 – 2.84 (m, 2H), 2.61 – 2.57 (m, 2H), 2.43 (s, 3H), 2.32 (s, 3H), 2.28 – 2.24 (m, 2H), 2.13 –1.97 (m, 4H), HRMS (ESI)forC 44 H 51 N9O6(M + H) + : calcd 802.4035; found, 802.4031.

[0109] Example 5: Synthesis of 4-[(2-(2-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)ethoxy)ethyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-5):

[0110]

[0111] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 49%. 1H NMR (400 MHz, DMSO-d6) δ 11.09(s, 1H), 10.29 (s, 1H), 9.00 (s, 1H), 8.22 (d, J = 2.4 Hz, 1H), 7.98 (d, J =8.6 Hz, 1H), 7.71 – 7.68 (m, 1H), 7.60 (dd, J = 8.5, 7.0 Hz, 1H), 7.17 (d, J= 8.6 Hz, 1H), 7.05 (d, J = 7.0 Hz, 1H), 6.63 (t, J = 5.9 Hz, 1H), 5.85 (p, J= 8.7 Hz, 1H), 5.04 (dd, J = 12.8, 5.4 Hz, 1H), 3.68 – 3.56 (m, 4H), 3.50 –3.49 (m, 2H), 2.99 (s, 1H), 2.89 – 2.80 (m, 2H), 2.68 – 2.54 (m, 2H), 2.43(s, 3H), 2.32 (s, 3H), 2.28 – 2.21 (m, 3H), 2.13 – 1.84 (m, 6H), 1.83 – 1.78(m, 3H), 1.70 – 1.53 (m, 6H). HRMS (ESI) for C 42 H 47 N9O7(M + H) + : calcd790.3671; found, 790.3665.

[0112] Example 6: Synthesis of 4-[(2-(2-(2-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyridino[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)ethoxy)ethoxy)ethyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-6):

[0113]

[0114] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 55%. 1H NMR (400 MHz, DMSO-d6) δ 11.13(s, 1H), 10.34 (s, 1H), 9.01 (s, 1H), 8.22 (s, 1H), 8.01 (d, J = 8.5 Hz, 1H), 7.68 (d, J = 8.8 Hz, 1H), 7.59 (dd, J = 8.6, 7.1 Hz, 1H), 7.16 (d, J = 8.6Hz, 1H), 7.04 (d, J = 7.0 Hz, 1H), 6.61 (t, J = 5.8 Hz, 1H), 5.84 (p, J = 8.9Hz, 1H), 5.07 (dd, J = 12.9, 5.4 Hz, 1H), 3.73 – 3.64 (m, 4H), 3.61 (s, 4H), 3.51 – 3.46 (m, 4H), 2.93 – 2.86 (m, 2H), 2.67 – 2.56 (m, 3H), 2.43 (s, 3H), 2.33 (s, 3H), HRMS (ESI)forC 44 H 51 N9O8(M + H) + : calcd 834.3933; found, 834.3928.

[0115] Example 7: Synthesis of 4-[(2-(2-(2-(2-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyridino[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)ethoxy)ethoxy)ethoxy)ethyl)amino]-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (S-7):

[0116]

[0117] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 53%. 1H NMR (400 MHz, DMSO-d6) δ 11.13(s, 1H), 10.34 (s, 1H), 9.00 (s, 1H), 8.23 ​​(s, 1H), 8.01 (d, J = 8.5 Hz, 1H), 7.69 (d, J = 8.8 Hz, 1H), 7.57 (dd, J = 8.6, 7.1 Hz, 1H), 7.14 (d, J = 8.6Hz, 1H), 7.03 (d, J = 7.0 Hz, 1H), 6.59 (t, J = 6.0 Hz, 1H), 5.84 (p, J = 8.9Hz, 1H), 5.06 (dd, J = 12.8, 5.4 Hz, 1H), 3.64 – 3.61 (m, 4H), 3.58 – 3.57(m, 4H), 3.56 – 3.52 (m, 6H), 3.51 – 3.46 (m, 6H), 2.93 – 2.86 (m, 1H), 2.68– 2.61 (m, 2H), 2.43 (s, 3H), 2.32 (s, 3H), 2.30 – 2.26 (m, 2H), 2.03 – 1.99 (m, 2H), 1.96 – 1.85 (m, 4H), 1.83 – 1.76 (m, 2H), 1.62 – 1.57 (m, 2H), 1.52– 1.44 (m, 2H). HRMS (ESI) for C 46 H 55 N9O9(M + H) + :calcd 878.4196; found,878.4211.

[0118] Example 8: Synthesis of 4-[(14-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-3,6,9,12-tetraoxatetradecyl)amino]-2-(2,6-dioxopiperidin-3-yl) (S-8):

[0119]

[0120] Following the synthesis method of S-1, a yellow solid was obtained with a yield of 49%. 1H NMR (400 MHz, DMSO-d6) δ 11.12(s, 1H), 10.36 (s, 1H), 9.00 (s, 1H), 8.25 (s, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.69 (d, J = 8.5 Hz, 1H), 7.56 (dd, J = 8.5, 7.1 Hz, 1H), 7.12 (d, J = 8.6Hz, 1H), 7.02 (d, J = 7.0 Hz, 1H), 6.58 (t, J = 5.8 Hz, 1H), 5.84 (p, J = 9.0Hz, 1H), 5.06 (dd, J = 12.8, 5.4 Hz, 1H), 3.90 – 3.79 (m, 2H), 3.61 – 3.60 (m, 4H), 3.58 – 3.56 (m, 4H), 3.56 – 3.55 (m, 4H), 3.54 – 3.53 (m, 2H), 3.52– 3.51 (m, 4H), 3.14 – 3.10 (m, 2H), 2.94 – 2.85 (m, 2H), 2.62 – 2.57 (m,1H), 2.43 (s, 3H), 2.32 (s, 3H), 2.28 – 2.23 (m, 2H), 2.21 – 2.12 (m, 2H),2.05 – 1.98 (m, 4H), 1.92 – 1.90 (m, 2H), 1.80 – 1.76 (m, 2H), 1.61 – 1.56(m, 2H), 1.49 – 1.47 (m, 2H). HRMS (ESI) for C 48 H 61 N9O 10 (M + H) + : calcd922.4458; found, 922.4466.

[0121] Example 9: Synthesis of 2-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)acetamide (S-9):

[0122]

[0123] M1 (446 mg, 1 mmol) and M10 (590 mg, 1.5 mmol) were dissolved in 10 mL of N,N-dimethylformamide, and N,N-diisopropylethylamine (387 mg, 3 mmol) was added. The mixture was reacted at 90 °C for 8 h. After the reaction was completed, S-9 was obtained by concentrated column chromatography, which yielded a yellow solid with a yield of 43%. 1 H NMR (400 MHz, DMSO-d6) δ 11.31 (s, 1H), 11.17 (s,1H), 10.11 (s, 1H), 9.02 (s, 1H), 8.82 (d, J = 8.5 Hz, 1H), 8.36 (d, J = 2.4Hz, 1H), 8.00 (d, J = 8.5 Hz, 1H), 7.87 (dd, J = 8.5, 7.3 Hz, 1H), 7.74 (dd,J = 8.6, 2.4 Hz, 1H), 7.62 (d, J = 7.3 Hz, 1H), 5.85 (p, J = 8.9 Hz, 1H),5.20 (dd, J = 12.9, 5.3 Hz, 1H), 3.29 – 3.18 (m, 2H), 3.00 – 2.89 (m, 3H), 2.69 – 2.59 (m, 4H), 2.47 – 2.39 (m, 5H), 2.33 (s, 3H), 2.29 – 2.25 (m, 2H),2.15 – 2.04 (m, 2H), 1.93 – 1.87 (m, 2H), 1.83 – 1.79 (m, 4H), 1.60 – 1.56(m, 2H).HRMS (ESI) for C 40 H 41 N9O7(M + H) + : calcd 760.3202; found, 760.3179.HRMS (ESI) for C 40 H 41 N9O7(M + H) + : calcd 760.3202; found, 760.3179.

[0124] Example 10: Synthesis of 3-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)propionamide (S-10):

[0125]

[0126] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 45%. 1 H NMR (400 MHz, DMSO-d6) δ 11.16(s, 1H), 10.59 (s, 1H), 10.18 (s, 1H), 9.01 (s, 1H), 8.60 (d, J = 8.4 Hz,1H), 8.28 (d, J = 2.4 Hz, 1H), 7.99 (d, J = 8.6 Hz, 1H), 7.84 (dd, J = 8.5,7.3 Hz, 1H), 7.71 (dd, J = 8.6, 2.4 Hz, 1H), 7.62 (d, J = 7.2 Hz, 1H), 5.85(p, J = 8.9 Hz, 1H), 5.15 (dd, J = 12.9, 5.3 Hz, 1H), 3.17 – 3.10 (m, 2H), 2.99 – 2.87 (m, 1H), 2.70 – 2.63 (m, 4H), 2.60 – 2.54 (m, 2H), 2.43 (s, 3H), 2.33 (s, 3H), 2.28 – 2.21 (m, 2H), 2.14 – 2.05 (m, 4H), 1.94 – 1.84 (m, 4H), 1.82 – 1.73 (m, 4H), 1.63 – 1.55 (m, 2H). HRMS (ESI) for C 41 H 43 N9O7(M + H) + :calcd 774.3358; found, 774.3348.

[0127] Example 11: Synthesis of 4-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)butyramide (S-11):

[0128]

[0129] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 42%. 1 H NMR (400 MHz, DMSO-d6) δ 11.17(s, 1H), 10.31 (s, 1H), 9.77 (s, 1H), 9.01 (s, 1H), 8.50 (d, J = 8.4 Hz, 1H),8.20 (s, 1H), 7.98 (d, J = 8.7 Hz, 1H), 7.85 (dd, J = 8.4, 7.3 Hz, 1H), 7.63(d, J = 7.3 Hz, 2H), 5.84 (p, J = 8.9 Hz, 1H), 5.15 (dd, J = 12.8, 5.4 Hz,1H), 2.95 – 2.86 (m, 2H), 2.68 – 2.54 (m, 5H), 2.43 (s, 3H), 2.33 (s, 3H),2.23 – 2.28 (m, 4H), 2.08 – 2.04 (m, 2H), 1.91 – 1.89 (m, 6H), 1.83 – 1.78(m, 4H), 1.63 – 1.57 (m, 4H). HRMS (ESI) for C 42 H 45 N9O7(M + H) + : calcd788.3515; found, 788.3510.

[0130] Example 12: Synthesis of 5-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)pentanamide (S-12):

[0131]

[0132] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 44%. 1 H NMR (400 MHz, DMSO-d6) δ 11.16(s, 1H), 10.33 (s, 1H), 9.80 (s, 1H), 9.01 (s, 1H), 8.45 (d, J = 8.4 Hz, 1H),8.26 (s, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.85 (t, J = 7.9 Hz, 1H), 7.71 (d, J= 8.7 Hz, 1H), 7.64 (d, J = 7.3 Hz, 1H), 5.85 (p, J = 8.8 Hz, 1H), 5.15 (dd,J = 12.8, 5.4 Hz, 1H), 2.95 – 2.86 (m, 2H), 2.43 (s, 3H), 2.33 (s, 3H), 2.29– 2.24 (m, 2H), 2.10 – 2.03 (m, 2H), 2.01 – 1.99 (m, 1H), 1.96 – 1.87 (m,4H), 1.84 – 1.78 (m, 4H), 1.72 – 1.66 (m, 3H), 1.61 – 1.59 (m, 2H), 1.28 –1.20 (m, 7H), 0.89 – 0.79 (m, 2H). HRMS (ESI) for C 43 H 47 N9O7(M + H) + : calcd802.3671; found, 802.3652.

[0133] Example 13: Synthesis of 6-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)hexanoamide (S-13):

[0134]

[0135] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 45%. 1H NMR (400 MHz, DMSO-d6) δ 11.16(s, 1H), 10.30 (s, 1H), 9.72 (s, 1H), 9.00 (s, 1H), 8.48 (d, J = 8.4 Hz, 1H),8.24 (s, 1H), 8.00 (d, J = 8.6 Hz, 1H), 7.84 (t, J = 7.9 Hz, 1H), 7.72 (d, J= 8.6 Hz, 1H), 7.62 (d, J = 7.3 Hz, 1H), 5.84 (p, J = 9.1 Hz, 1H), 5.15 (dd,J = 12.7, 5.4 Hz, 1H), 3.19 – 3.06 (m, 2H), 2.95 – 2.86 (m, 1H), 2.64 – 2.59 (m, 4H), 2.43 (s, 3H), 2.32 (s, 3H), 2.28 – 2.24 (m, 2H), 2.10 – 2.06 (m,2H), 1.99 – 1.88 (m, 4H), 1.80 – 1.75 (m, 6H), 1.71 – 1.63 (m, 4H), 1.62 –1.56 (m, 4H), 1.41 – 1.33 (m, 2H). HRMS (ESI) for C 44 H 49 N9O7(M + H) + : calcd816.3828; found, 816.3813.

[0136] Example 14: Synthesis of 7-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)heptamide (S-14):

[0137]

[0138] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 42%. 1H NMR (400 MHz, DMSO-d6) δ 11.17(s, 1H), 10.33 (s, 1H), 9.72 (s, 1H), 9.00 (s, 1H), 8.47 (d, J = 8.4 Hz, 1H),8.25 (s, 1H), 8.01 (d, J = 8.6 Hz, 1H), 7.84 (t, J = 7.9 Hz, 1H), 7.72 (d, J= 8.7 Hz, 1H), 7.63 (d, J = 7.3 Hz, 1H), 5.85 (p, J = 8.7 Hz, 1H), 5.15 (dd,J = 12.7, 5.4 Hz, 1H), 2.95 – 2.86 (m, 2H), 2.68 – 2.54 (m, 3H), 2.43 (s,3H), 2.32 (s, 3H), 2.27 – 2.22 (m, 4H), 2.20 – 1.94 (m, 4H), 1.90 – 1.86 (m,2H), 1.85 – 1.71 (m, 6H), 1.67 – 1.58 (m, 6H), 1.49 – 1.24 (m, 6H). HRMS(ESI) for C 45 H 51 N9O7(M + H) + : calcd 830.3984; found, 830.3972.

[0139] Example 15: Synthesis of 8-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)octamide (S-15):

[0140]

[0141] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 45%. 1H NMR (400 MHz, DMSO-d6) δ 11.17(s, 1H), 10.33 (s, 1H), 9.71 (s, 1H), 9.01 (s, 1H), 8.48 (d, J = 8.4 Hz, 1H),8.26 (s, 1H), 8.02 (d, J = 8.6 Hz, 1H), 7.84 (t, J = 7.9 Hz, 1H), 7.72 (d, J= 7.2 Hz, 1H), 7.62 (d, J = 7.3 Hz, 1H), 5.86 (p, J = 8.8 Hz, 1H), 5.16 (dd,J = 12.7, 5.4 Hz, 1H), 2.96 – 2.86 (m, 2H), 2.66 – 2.62 (m, 1H), 2.59 – 2.56(m, 2H), 2.43 (s, 3H), 2.33 (s, 3H), 2.29 – 2.23 (m, 2H), 2.12 – 2.03 (m,2H), 2.00 – 1.93 (m, 2H), 1.93 – 1.87 (m, 3H), 1.86 – 1.75 (m, 4H), 1.72 –1.50 (m, 8H), 1.41 – 1.29 (m, 7H). HRMS (ESI) for C 46 H 53 N9O7(M + H) + : calcd844.4141; found, 844.4120.

[0142] Example 16: Synthesis of 9-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)nonanoamide (S-16):

[0143]

[0144] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 44%. 1H NMR (400 MHz, DMSO-d6) δ 11.18(s, 1H), 10.27 (s, 1H), 9.70 (s, 1H), 9.00 (s, 1H), 8.48 (d, J = 8.4 Hz, 1H),8.24 (s, 1H), 7.99 (d, J = 8.6 Hz, 1H), 7.83 (t, J = 7.9 Hz, 1H), 7.73 (d, J= 8.6 Hz, 1H), 7.61 (d, J = 7.3 Hz, 1H), 5.83 (p, J = 8.8 Hz, 1H), 5.15 (dd,J = 12.8, 5.4 Hz, 1H), 2.99 – 2.85 (m, 3H), 2.70 – 2.54 (m, 3H), 2.43 (s,3H), 2.32 (s, 3H), 2.29 – 2.21 (m, 4H), 2.13 – 1.98 (m, 3H), 1.95 – 1.86 (m,3H), 1.83 – 1.71 (m, 6H), 1.67 – 1.57 (m, 6H), 1.48 – 1.42 (m, 2H), 1.32 –1.29 (m, 5H). HRMS (ESI) for C 47 H 55 N9O7(M + H) + :calcd 858.4297; found,858.4292.

[0145] Example 17: Synthesis of 10-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)decanoamide (S-17):

[0146]

[0147] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 47%. 1H NMR (400 MHz, DMSO-d6) δ 11.17(s, 1H), 10.31 (d, J = 3.3 Hz, 1H), 9.70 (s, 1H), 9.00 (s, 1H), 8.48 (d, J =8.4 Hz, 1H), 8.25 (d, J = 2.4 Hz, 1H), 8.01 (dd, J = 8.7, 3.4 Hz, 1H), 7.83 (dd, J = 8.4, 7.3 Hz, 1H), 7.67 (dd, J = 40.7, 7.1 Hz, 2H), 5.85 (p, J = 8.9Hz, 1H), 5.15 (dd, J = 12.7, 5.4 Hz, 1H), 2.95 – 2.84 (m, 2H), 2.68 – 2.55(m, 5H), 2.49 – 2.45 (m, 3H), 2.43 (s, 3H), 2.33 (s, 3H), 2.29 – 2.24 (m,4H), 2.10 – 2.04 (m, 2H), 1.94 – 1.85 (m, 7H), 1.83 – 1.76 (m, 7H), 1.64 –1.56 (m, 9H). HRMS (ESI) for C 48 H 57 N9O7(M + H) + :calcd 872.4454; found,872.4448.

[0148] Example 18: Synthesis of 11-(4-(6-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)pyridin-3-yl)piperidin-1-yl)-N-(2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindoline-4-yl)undecanoamide (S-18):

[0149]

[0150] Following the synthesis method of S-9, a yellow solid was obtained with a yield of 46%. 1H NMR (400 MHz, DMSO-d6) δ 11.17(s, 1H), 10.27 (s, 1H), 9.69 (s, 1H), 9.00 (s, 1H), 8.48 (d, J = 8.4 Hz, 1H), 8.24 (d, J = 2.4 Hz, 1H), 7.99 (d, J = 8.6 Hz, 1H), 7.83 (dd, J = 8.4, 7.3Hz, 1H), 7.73 (dd, J = 8.7, 2.5 Hz, 1H), 7.61 (d, J = 7.2 Hz, 1H), 5.84 (p, J= 8.8 Hz, 1H), 5.15 (dd, J = 12.7, 5.4 Hz, 1H), 2.97 – 2.84 (m, 3H), 2.67 –2.54 (m, 2H), 2.48 – 2.45 (m, 2H), 2.43 (s, 3H), 2.32 (s, 3H), 2.30 – 2.23(m, 4H), 2.11 – 2.02 (m, 2H), 1.96 – 1.87 (m, 4H), 1.81 – 1.74 (m, 4H), 1.71 – 1.67 (m, 2H), 1.66 – 1.57 (m, 6H), 1.47 – 1.41 (m, 2H), 1.32 – 1.25 (m,10H). HRMS (ESI) for C 49 H 59 N9O7(M + H) + : calcd 886.4610; found, 886.4605.

[0151] III. Biological Evaluation Experiment:

[0152] (1) Assay of CDK4 in vitro degradation activity:

[0153] The ability of the compounds in the examples to degrade CDK4 protein was evaluated using Western blotting, and Western blotting analysis was performed in breast cancer MCF-7 cells.

[0154] Experimental Procedure: MCF7 cells were seeded in 6-well plates and cultured at 37 °C in a 5% CO2 incubator for 24 h until cell adhesion was achieved. The test compound was added, and the cells were cultured for another 24 h. Cells were collected, centrifuged, and the supernatant was discarded. Cells were washed once with PBS. Lysis buffer containing protease and phosphatase inhibitors was added to the cell pellet. Protein samples were obtained after lysis and quantified. Protein samples were mixed with LDS loading buffer and boiled. After separation by SDS-PAGE, the samples were transferred to a PVDF membrane. The membrane was blocked with 5% skim milk for 1 h, and then incubated overnight at 4 °C with primary antibodies (β-Actin, 1:5000; CDK4, 1:1000). After washing with TBST, the membrane was incubated with HRP-labeled secondary antibody (1:5000) at room temperature for 1 h. After washing, chemiluminescence imaging was performed, and protein expression levels were analyzed using ImageJ.

[0155] Experimental results show that compounds S-1 to S-18 prepared in the embodiments of the present invention have significant degradation activity against CDK4 protein. The results are shown in Table 1. The degradation rates of compounds against CDK4 protein at 200 nM or 500 nM are classified according to the description:

[0156] Table 1. Degradation activity of the compounds of the present invention on CDK4 protein

[0157]

[0158] "A" indicates a CDK4 protein degradation rate of 50% or higher; "B" indicates a CDK4 protein degradation rate of less than 50% but greater than or equal to 25%; "C" indicates a CDK4 protein degradation rate of less than 25% but greater than or equal to 10%; "D" indicates a CDK4 protein degradation rate of less than 10%.

Claims

1. A compound of formula (S) that targets and degrades CDK4 protein, or a pharmaceutically acceptable salt thereof. （S） In the formula, linker is a linking group, which represents a straight or branched alkylene chain with a total length of 1-20 atoms, wherein the straight or branched alkylene chain is optionally interrupted once or more by one or more -O-, -CO-, -CONH-, -NH-, or any combination thereof.

2. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, characterized in that, The linker can be selected from the following structures: -(CH2) m -NH-, m = 1-8; -(CH2CH2O) n -CH2CH2NH-, n = 1-8;-(CH2) p -CONH-, p = 1-12.

3. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, characterized in that, The linker can be selected from the following structures: -(CH2) m -NH-, m = 3-6; -(CH2CH2O) n -CH2CH2NH-, n = 1-4;-(CH2) p -CONH-, p = 1-10.

4. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, characterized in that, The compound is selected from any compound with the structural formulas shown in formulas (S-1) to (S-18):

5. The compound according to claim 1 or a pharmaceutically acceptable salt thereof, characterized in that, The pharmaceutically acceptable salt is an acid addition salt of a compound of general formula (S), wherein the acid used for salt formation is selected from inorganic acids and organic acids, wherein the inorganic acid is selected from hydrochloric acid, sulfuric acid, and phosphoric acid, and the organic acid is selected from acetic acid, propionic acid, butyric acid, maleic acid, p-toluenesulfonic acid, malic acid, methanesulfonic acid, malonic acid, trichloroacetic acid, trifluoroacetic acid, fumaric acid, citric acid, diaspholic acid, camphoric acid, cinnamic acid, aspartic acid, and tartaric acid.

6. A method for preparing a compound according to any one of claims 1 to 5 or a pharmaceutically acceptable salt thereof, characterized in that, Includes the following steps: Method 1: Compound A and compound B were dissolved in N,N-dimethylformamide, and N,N-diisopropylethylamine was added. After the reaction was completed, the final product S was obtained. R1 is selected from: -(CH2) m -NH2, m = 3-6; -(CH2CH2O) n -CH2CH2NH2, n = 1-4; Method 2: Compounds C and D were dissolved in N,N-dimethylformamide, and N,N-diisopropylethylamine was added. After the reaction was completed, the final product S was obtained. Where p = 1-10.

7. A pharmaceutical composition, characterized in that, It comprises the compound of any one of claims 1 to 5 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

8. The pharmaceutical composition according to claim 7, characterized in that, The dosage form of the pharmaceutical composition is selected from at least one of tablets, capsules, granules, injections, powder for injection, eye drops, powders, pills, transdermal patches, ointments, aerosols, emulsions, liniments, suppositories, films, controlled-release formulations, and nanoformulations.

9. The use of the compounds according to claims 1 to 5 or pharmaceutically acceptable salts thereof in the preparation of medicaments for the prevention and / or treatment of tumor-related diseases.

10. The application according to claim 9, wherein the tumor-related diseases are selected from: breast cancer, ovarian cancer, lung cancer, gastric cancer, prostate cancer, testicular cancer, leukemia, colon cancer, multiple myeloma, liver cancer, pancreatic cancer, melanoma, glioma, brain glioma, pituitary adenoma, and various solid tumors and hematologic malignancies.

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