A targeted protein degrader using artemisinin analogues as hydrophobic tags, its preparation method and application

Abstract

This invention discloses a targeted protein degrader using an artemisinin analog as a hydrophobic tag, its preparation method, and its application. The structural formula of the targeted protein degrader of this invention is shown in formula (II), (III), or (IV). The targeted protein degrader of this invention exhibits activity in inhibiting human breast cancer cells while also possessing good degradation activity. The targeted protein degrader can also be used in the preparation of drugs that target and degrade estrogen receptors or in anti-breast cancer drugs.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical technology, and in particular to a targeted protein degrader using artemisinin analogues as hydrophobic tags, its preparation method, and its application. Background Technology

[0002] In recent years, breast cancer has become one of the leading causes of death. Currently, the main treatment for breast cancer is traditional chemotherapy, but this still has limitations, such as low bioavailability, significant drug toxicity, and damage to the immune system. Therefore, choosing a more effective treatment is crucial for breast cancer patients. Targeted protein degradation strategies, as a revolutionary drug development strategy, have enormous potential in overcoming drug resistance. Taking estrogen receptor α (ERα) as an example, it plays a crucial role in the development and progression of breast cancer and is an important molecular target for breast cancer treatment. Overcoming drug resistance has become a key criterion for evaluating the efficacy of drugs targeting this target in clinical treatment of breast cancer. For strategies targeting ERα degradation, the ubiquitin-proteasome system is a major degradation pathway. The most representative technology is the protein degradation-targeting chimera (PROTAC), which directly binds to E3 ubiquitin ligase via a ternary complex E3 ligand, causing protein degradation through ubiquitin labeling. A representative ERα degrader, ARV-471, is currently in phase III clinical trials.

[0003] For PROTAC technology, its structural characteristics result in a large molecular weight and a lack of tissue specificity, leading to poor oral absorption and membrane permeability. This poses significant challenges regarding its oral drugability and toxicity. Therefore, its unfavorable pharmacokinetic properties are a major obstacle to its pharmacodynamics. Thus, exploring new degradation strategies, comparing the advantages and disadvantages of various degradation strategies, and studying the mechanisms of action and bioactivity of different types of degradative agents are of great significance for the efficacy of targeted drug therapy. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a targeted protein degrader using artemisinin analogs as hydrophobic tags, along with its preparation method and applications. In this invention, artemisinin analogs serve as hydrophobic groups in bifunctional molecules. For the target protein ligand structure, benzothiophene compounds (targeting ERα), methylpyridinidine compounds (targeting CDK4 / 6), and octanoylaniline isohydroxamic acid compounds (targeting HDAC6) are selected as the basic backbones. Then, hydrophobic tags of artemisinin analogs are added to the compounds via side-chain introduction, resulting in the design and synthesis of ERα-degrading molecules, CDK4 / 6-degrading molecules, and HDAC6-degrading molecules. By selecting linkers of different lengths, the goal is to maintain the binding of the two proteins spatially without affecting their interaction. The influence of artemisinin analogs as hydrophobic tags on different proteins is verified by selecting different target protein ligands.

[0005] This invention provides a hydrophobic tag based on artemisinin-like compounds, the structural formula of which is shown in formula (I):

[0006]

[0007] This invention provides a targeted protein degrader, comprising a hydrophobic tag, a target protein ligand, and a linker; the hydrophobic tag and the target protein ligand are connected by the linker; the target protein ligand is any one of benzothiophene compounds, methylpyridinidine compounds, and octanoylaniline isohydroxamic acid compounds.

[0008] Furthermore, the linker is any one of an alkyl chain or an alkoxy group.

[0009] Furthermore, the targeted protein degrader has a structure as shown in formula (II), (III), or (IV):

[0010] Where n is any integer from 1 to 10;

[0011] Where n is any integer from 1 to 10;

[0012] Where n is any integer from 1 to 10.

[0013] Furthermore, the compounds of formula (II) include, but are not limited to, the following compounds:

[0014] (3R,6R,9S,11R,11aR)-N-(2-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)ethyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA2), (3R,6R,9S,11R,11aR)-N-(3-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)propyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA3) (3R,6R,9S,11R,11aR)-N-(4-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)butyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA4), (3R,6R,9S,11R,11aR)-N-(6-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)hexyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA6).

[0015] Furthermore, the compounds of formula (III) include, but are not limited to, the following compounds:

[0016] (3R,6R,9S,11R,11aR)-N-(3-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)propyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxane[3,4-d]isobenzofuran-9-carboxamide (PA).

[0017] Furthermore, the compounds of formula (IV) include, but are not limited to, the following compounds:

[0018] N 1 -hydroxy-N 8 -(4-((3R,6R,9S,11R,11aR)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxane-heptane[3,4-d]isobenzofuran-9-carbamoyl)butamido)phenyl)octadiamide (SA).

[0019] The present invention also provides a method for synthesizing the target protein degrader, comprising the following steps:

[0020] 1) Synthesis of artemisinin analogues;

[0021] 2) Synthesis of target protein ligands with linkers, followed by amidation reaction of the artemisinin analogue described in step 1) with the target protein ligand to obtain a target protein degrading agent.

[0022] Furthermore, step 1) the synthesis of artemisinin analogues specifically includes the following steps:

[0023] S1. Compound 1 was dissolved in tetrahydrofuran, cooled to 0°C, and boron trifluoride diethyl ether was added dropwise. The reaction was carried out for 24 hours. After the reaction was completed, the reaction was quenched with saturated sodium bicarbonate, extracted, dried, distilled, and purified to obtain compound 2.

[0024] S2. Compound 2 was dissolved in carbon tetrachloride, and bromine was slowly added dropwise at 0°C with stirring. After the reaction was completed, diethyl ether was added for dilution, sodium thiosulfate was added for quenching, the mixture was dried, and the mixture was distilled under reduced pressure to obtain compound 3.

[0025] S3. Dissolve compound 3 in dichloromethane, add triethylamine, stir until the reaction is complete, neutralize excess triethylamine, wash, dry, filter, concentrate, and purify to obtain compound 4;

[0026] S4. Compound 4 was dissolved in a 1,4-dioxane solution, an aqueous solution containing aminosulfonic acid was added, and the mixture was stirred overnight at 0°C. NaClO2 and water were added, and the mixture was stirred. Na2SO3 was added, and the mixture was diluted, extracted, washed, dried, and evaporated to obtain compound 5, which is an artemisinin analogue.

[0027] Furthermore, step 2) the synthesis of the target protein ligand with the linker specifically includes the following steps:

[0028] 1) When the target protein ligand is a benzothiophene compound, the method for synthesizing the target protein degrader includes the following steps:

[0029] S1,4-acetylbenzoic acid was stirred with oxalyl chloride at room temperature to give an acyl chloride intermediate. The intermediate reacted with compound 7 and anhydrous aluminum chloride to give compound 8. Compound 8 was dissolved in anoxic ethanol / water solution, and sodium acetate was added and stirred at 100°C to give compound 9. Compound 9 was reacted with (n-bromon-alkyl)carbamate tert-butyl ester to give compound 10. Boron tribromide was used to remove methyl and Boc groups to give compound 11. The n is 1 to 10. Compound 11 is a benzothiophene compound with a linker.

[0030] S2. Using HATU as a catalyst and DIPEA as a base, in DMF solvent, compound 11 and compound 5 are subjected to an amidation reaction;

[0031] 2) When the target protein ligand is a methylpyridinidine compound, the method for synthesizing the target protein degrader includes the following steps:

[0032] S1. Compound 13 and compound 14 were mixed and reacted under argon, DIPEA and DMSO, extracted, dried, filtered and concentrated to obtain compound 15;

[0033] S2. Dissolve compound 15 in dichloromethane, add TFA dropwise at 0°C, stir, extract, wash, dry, filter and concentrate to obtain compound 16;

[0034] S3. Dissolve compound 5 in DMF, add EDCI, HOBT and triethylamine, stir under inert gas, add compound 16, stir at room temperature, after the reaction is complete, extract, dry and purify;

[0035] 3) When the target protein ligand is an octanoyl aniline isohydroxamic acid compound, the method for synthesizing the target protein degrading agent includes the following steps:

[0036] S1. Compound 18 was reacted with compound 19 at room temperature to give compound 20;

[0037] S2. Remove the Boc group from compound 20 to obtain compound 21;

[0038] S3. Compound 21 and compound 22 are subjected to an amide condensation reaction to obtain compound 23;

[0039] S4. Remove the Boc group from compound 23 to obtain compound 24;

[0040] S5. Compound 24 is subjected to an amide condensation reaction with compound 5 to obtain compound 25;

[0041] S6. Hydroxylamine hydrochloride is reacted with sodium hydroxide to generate hydroxylamine, and the hydroxylamine is reacted with compound 25 under alkaline conditions.

[0042] The present invention also provides a pharmaceutical composition comprising the hydrophobic tag or the targeted protein degrader described herein.

[0043] Furthermore, this also includes pharmaceutically acceptable carriers and pharmaceutically acceptable dosage forms.

[0044] The present invention also provides applications of the hydrophobic tags or the targeted protein degraders described herein, including the preparation of drugs that target the degradation of hormone receptors or the preparation of drugs against breast cancer.

[0045] In summary, compared with the prior art, the present invention achieves the following technical effects:

[0046] This invention discovers that artemisinin-like compounds can serve as hydrophobic tags and are coupled with various specific POIs (such as ERα, CDK6, and HDAC6) to synthesize a series of targeted protein degraders. The obtained target compounds all exhibit certain POI binding abilities. By using artemisinin as a hydrophobic tag, not only can the compounds achieve MCF-7 cell inhibitory activity superior to the parent compounds, but they can also possess good degradation activity.

[0047] This invention introduces a hydrophobic tag that is simple to synthesize and has a high yield. Compared to PROTAC, the resulting target molecule has a smaller molecular weight and superior cell membrane permeability and druggability. By introducing artemisinin-like compounds as hydrophobic tags, a successful technique for selectively degrading target proteins can be achieved. Its modular design strategy allows for broader application of rationally designed binding pockets and may potentially yield active compounds targeting undrugable targets. Furthermore, the discovery that artemisinin-like compounds can serve as a class of hydrophobic tags offers potential for future modular strategies and provides insights and references for developing novel targeted protein degraders. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a Western blot analysis of ERα protein in MCF-7 cells after treatment with 10 μM compounds raloxifene, artemisinin, RA2, RA3, RA4, and RA6 for 24 h, as described in an embodiment of the present invention.

[0050] Figure 2 This is a Western blot analysis of CDK6 protein in MCF-7 cells after treatment with compound PA at 0.1 μM, 1.0 μM, and 10 μM for 24 h, as described in an embodiment of the present invention.

[0051] Figure 3 This is a Western blot analysis of HDAC6 protein in MCF-7 cells after treatment with 0.1 μM, 1.0 μM, and 10 μM compound SA for 24 h, as described in an embodiment of the present invention. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 should fall within the scope of protection of the present invention.

[0053] Example 1

[0054] The method for preparing benzothiophene compounds containing hydrophobic tags according to the present invention includes the following steps:

[0055] (1) Synthesis of artemisinin analogues

[0056] The synthetic route is shown in the reaction formula below, and specifically includes the following steps:

[0057]

[0058] 1) Synthesis of (3R,6R,12R,12aR)-3,6,9-trimethyl-3,4,5,5a,6,7,8,8a-octahydro-12H-3,12-epoxy[1,2]dioxane[4,3-I]isochromene (compound 2)

[0059] Compound 1 (4.0 g, 14.17 mmol) was dissolved in 50 mL of tetrahydrofuran. After cooling to 0 °C, boron trifluoride diethyl ether (2.09 mL, 18.37 mmol) was slowly added dropwise, and the reaction was allowed to proceed for 24 h. The reaction was then quenched with saturated sodium bicarbonate. Extraction was performed with ethyl acetate and dried over anhydrous sodium sulfate. Purification was achieved by column chromatography under reduced pressure, using petroleum ether:ethyl acetate = 50:1 as eluent, to give compound 2 as a white solid, 2.8 g, in 74.2% yield.

[0060] 2. Synthesis of (3R,6R,12R,12aR)-9-bromo-3,6,9-trimethyldecahydro-12H-3,12-epoxy[1,2]dioxane[4,3-I]isochrom-10-ol (compound 3)

[0061] Compound 2 (2.0 g, 7.5 mmol) was dissolved in 40 mL of carbon tetrachloride. Bromine (11.3 mL, 11.3 mmol, 1.2 equiv) was slowly added dropwise at 0 °C, and the mixture was stirred for 30 minutes. 20 mL of distilled water was added, and the mixture was stirred for another 2 hours. After the reaction was complete, the mixture was diluted with diethyl ether, and excess bromine was quenched with sodium thiosulfate. The mixture was dried over anhydrous sodium sulfate and distilled under reduced pressure before proceeding to the next step of the reaction. Compound 3 (1.7 g, 81.8% yield) was obtained.

[0062] 3) Synthesis of (3R,6R,9S,11R,11aR)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxane-heptane[3,4-d]isobenzofuran-9-carboxaldehyde (compound 4)

[0063] Compound 3 (2.5 g, 6.9 mmol) was dissolved in 150 mL of dichloromethane, and then triethylamine (TEA) (17.2 mmol, 2.5 mL, 2.5 equiv) was added. The reaction mixture was stirred at room temperature until the reaction was complete as monitored by TLC. The mixture was then treated with HCl (0.6 N) to neutralize excess TEA. The organic layer was washed with NaHCO3, dried over anhydrous Na2SO4, filtered, and concentrated to give a crude product, which was purified by column chromatography to give compound 4 (1.8 g, 91% yield) as fine milky white crystals.

[0064] 4. Synthesis of (3R,6R,9S,11R,11aR)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxane[3,4-d]isobenzofuran-9-carboxylic acid (compound 5)

[0065] Compound 4 (1.3 g, 4.6 mmol) was dissolved in a solution of 1,4-dioxane (50 mL), followed by the addition of an aqueous solution (17.5 mL) containing aminosulfonic acid (1.8 g, 18.77 mmol). The mixture was stirred at 0 °C for 20 h, and then NaClO2 (1.7 g, 18.77 mmol) and water (12.5 mL) were added. After stirring for 30 min, Na2SO3 (1.16 g) was added, and the mixture was diluted with water (50 mL). The mixture was extracted with diethyl ether (3 × 100 mL), the organic layer was washed with brine, dried over anhydrous Na2SO4, and evaporated. A brown solid product (1.1 g, 80%) was obtained.

[0066] (2) Synthesis of benzothiophene derivatives with linkers of different lengths

[0067] The synthetic route is shown in the reaction formula below, and specifically includes the following steps:

[0068]

[0069] The specific synthesis involves reacting 4-acetylbenzoic acid with oxaloyl chloride at room temperature to obtain an acyl chloride intermediate. The intermediate is then reacted with 6-methoxy-2-(4-methoxyphenyl)benzothiophene (compound 7) and anhydrous aluminum chloride at room temperature to obtain compound 8. Compound 8 is dissolved in an anaerobic ethanol / water (2:1) solution, and sodium acetate is added and stirred at 100°C to obtain compound 9. Compound 9 is reacted with tert-butyl (n-bromon-alkyl)carbamate of different chain lengths to obtain compound 10. Subsequently, boron tribromide is used to remove the methyl and Boc groups to obtain benzothiophene derivatives 11 (n = 2, 3, 4, 6, 8) with linkers of different lengths.

[0070] (3) Synthesis of benzothiophene compounds with artemisinin analog hydrophobic tags (for targeting ERα)

[0071] After obtaining benzothiophene derivatives 11a–d with side chains of different lengths, these four compounds were respectively subjected to amidation reactions with an artemisinin analog (compound 5). The synthetic route is shown in the following reaction formula:

[0072]

[0073] Using HATU as a catalyst and DIPEA as a base, and in the presence of DMF as a solvent, final products 12a–d (n = 2, 3, 4, 6, 8) with artemisinin-like tags and linkers of varying lengths were synthesized. Compared to PROTAC, this class of compounds has inexpensive and readily available starting materials, is rapidly synthesized, and is relatively simple to operate.

[0074] The following embodiments are used to further illustrate the present invention, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0075] (4) Synthesis of methylpyridopyrimidine compounds with artemisinin analog hydrophobic tags (targeting CDK4 / 6)

[0076] The synthetic route is shown in the reaction formula below, and specifically includes the following steps:

[0077]

[0078] 1) Synthesis of tert-butyl carbamate (compound 15) ((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)propyl)carbamate)

[0079] Under an argon atmosphere, compound 13 (100 mg, 0.33 mmol) and 5 mL of anhydrous DMSO were added to a 50 mL round-bottom flask. A mixture of compound 14 (57.0 mg, 0.33 mmol) and DIPEA (187.0 mg, 0.5 mmol) in DMSO (3 mL) was added dropwise over 3 min. The reaction was carried out at room temperature for 2 h. After the reaction was complete, the reaction mixture was extracted with 25 mL of ethyl acetate and saturated sodium chloride solution (25 mL × 3). The organic layer was dried over anhydrous Na₂SO₄, filtered, and concentrated to obtain the crude product. This crude product was purified by column chromatography to obtain a white solid compound 15 (120 mg, 81.9%).

[0080] 2) Synthesis of 6-acetyl-2-((3-aminopropyl)amino)-8-cyclopentyl-5-methylpyrido[2,3-d]pyrimidine-7(8H)-one (compound 16)

[0081] Compound 15 (100 mg, 0.23 mmol) was dissolved in dichloromethane, and TFA was added dropwise at 0 °C. The mixture was then stirred at 0 °C for 4 h. The resulting solution was poured into ice water and extracted with CH2Cl2 (3 × 25 mL). The organic layers were combined, washed with saturated NaHCO3 (3 × 40 mL), dried with anhydrous Na2SO4, filtered, and concentrated to give crude compound 16, which was used directly in the next reaction.

[0082] 3)(3R,6R,9S,11R,11aR)-N-(3-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)propyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxacyclopropane[3,4-d]isobenzofuran-9-carboxamide (compound 17)

[0083] Compound 5 (78.2 mg, 0.26 mmol) was dissolved in 10 mL of DMF in a 50 mL single-necked flask. EDCI (60.4 mg, 0.32 mmol), HOBT (42.6 mg, 0.32 mmol), and triethylamine (53.0 mg, 0.52 mmol) were added. The mixture was stirred under an inert atmosphere for half an hour. Then, compound 16 (90.0 mg, 0.26 mmol) was added, and the mixture was stirred at room temperature for 4 hours. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was evaporated to dryness and then mixed. The mixture was purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲 The alcohol ratio was 100:1-10:1, yielding 81 mg of white solid compound 17, with a yield of 49.9%.

[0084] (6) Synthesis of octanoyl aniline isohydroxamic acid compounds with artemisinin analog hydrophobic tags (targeting HDAC6)

[0085] The synthetic route is shown in the reaction formula below, and specifically includes the following steps:

[0086]

[0087] (4-Aminophenyl)carbamate tert-butyl ester (compound 18) was stirred with methyl 8-chloro-8-oxooctanoate (compound 19) at room temperature to give compound 20. Subsequently, the Boc group was removed by stirring with trifluoroacetic acid at 0°C to give compound 21. Compound 21 was amide-condensed with Boc-4-aminobutyric acid (compound 22) using EDCI, HOBT and triethylamine to give compound 23. Subsequently, the Boc group was removed by HCl at 45°C to give compound 24. Compound 24 was amide-condensed with compound 5 to give compound 25. Subsequently, hydroxylamine hydrochloride was reacted with sodium hydroxide to generate hydroxylamine. Hydroxylamine was reacted with compound 25 under alkaline conditions to give the final product compound 26.

[0088] Example 2

[0089] Preparation of (3R,6R,9S,11R,11aR)-N-(2-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)ethyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA2):

[0090]

[0091] Compound 5 (100 mg, 0.33 mmol) was dissolved in 10 mL of DMF in a 50 mL single-necked flask. HATU (152.9 mg, 0.4 mmol) and DIPEA (86.6 mg, 0.66 mmol) were added, and the mixture was stirred for half an hour under an inert atmosphere. Then, compound 11a (n = 2, 135.9 mg, 0.33 mmol) was added, and the mixture was stirred overnight at room temperature. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was evaporated to dryness and mixed. The mixture was then purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 84 mg of yellow solid compound 12a, with a yield of 37.1%.

[0092] 11H NMR (400 MHz, Methanol-d4) δ 7.66 (d, J = 8.8 Hz, 2H), 7.36 (d, J = 8.8 Hz, 1H), 7.24 (d, J = 2.3 Hz, 1H), 7.17 (d, J = 8.6 Hz, 2H), 6.83 (dd, J = 8.8, 2.3 Hz, 1H), 6.79 (d, J = 8.9 Hz, 2H), 6.61 (d, J = 8.6 Hz, 2H), 5.67 (s, 1H), 4.04 (tq, J = 10.2, 6.0, 5.2 Hz, 2H), 3.63 (dt, J = 14.1, 5.1 Hz, 1H), 3.46 (ddd, J = 14.0, 6.6, 4.5 Hz, 1H), 2.22 (ddd, J = 14.5, 12.9, 3.9 Hz, 1H), 2.08 (dd, J = 13.0, 6.4 Hz, 1H), 2.01 (dt, J = 14.5, 3.8 Hz, 1H), 1.90 (dt, J = 13.7, 4.4 Hz, 1H), 1.71 (ddd, J = 12.8, 6.2, 3.1 Hz, 1H), 1.64 (s, 3H), 1.33 (s, 4H), 1.25 (dd, J = 12.8, 4.2 Hz, 1H), 1.18 (dd, J = 13.1, 3.2 Hz, 1H), 0.97 (td, J = 12.9, 12.5, 2.8 Hz, 2H), 0.83 (d, J = 6.3 Hz, 4H). 13C NMR (101 MHz, CD3OD) δ 192.86, 173.66, 161.94, 156.61, 154.15, 141.24, 138.80, 131.64, 130.87, 129.15, 128.74, 128.54, 123.36, 122.07, 113.89, 113.42, 112.69, 105.31, 102.36, 96.23, 86.38, 85.04, 64.76, 50.17, 36.82, 35.39, 35.14, 30.66, 24.09, 23.35, 22.78, 22.72, 17.44. ESI-HRMS m / z calcd for C38H39NO9SNa + 708.2243, found 722.2240 [M+Na] + . HPLC purity 98%

[0093] Example 3

[0094] Preparation of (3R,6R,9S,11R,11aR)-N-(3-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)propyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA3):

[0095]

[0096] Compound 5 (100 mg, 0.33 mmol) was placed in a 50 mL single-necked flask, dissolved in 10 mL of DMF, and HATU (152.9 mg, 0.4 mmol) and DIPEA (86.6 mg, 0.66 mmol) were added. The mixture was stirred for half an hour under an inert atmosphere, and then compound 11b (n = 3, 140.6 mg, 0.33 mmol) was added. The mixture was stirred overnight at room temperature. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was dried by rotary evaporation and then mixed. The mixture was purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 80 mg of yellow solid compound 12b, with a yield of 34.6%.

[0097] 1 H NMR (400MHz, Methanol-d4) δ7.67(d,J=8.9Hz,2H),7.36(d,J=8.7Hz,1H),7.25(d,J=2.3Hz,1H),7.18(dt,J=9.5,2.6Hz,2H),6.8 5(dt,J=4.3,2.1Hz,1H),6.82(d,J=9.1Hz,2H),6.62(d,J=8.6Hz,2H),5.69(s,1H),4.01(t,J=5.9Hz,2H),3.34(s,2H),2.23(ddd ,J=14.5,12.9,3.9Hz,1H),2.10(dd,J=12.8,6.5Hz,1H),2.06–1.88(m,5H),1.79(ddd,J=12.7,6.2,3.0Hz,1H),1.64(s,3H),1.3 4(s,3H),1.28(s,2H),1.19(s,1H),1.09–1.03(m,1H),1.00(dd,J=13.0,2.9Hz,1H),0.96(d,J=6.3Hz,1H),0.87(d,J=6.3Hz,3H). 13C NMR (101MHz, CD3OD) δ194.20,174.56,163.35,157.85,155.40,142.35,140. 03,132.92,132.11,130.23,129.97,129.93,129.86,124.66,123.33,115.1 3,114.66,113.99,106.54,103.61,97.39,87.64,86.37,66.05,51.30,36.6 5,36.39,36.00,31.97,28.38,25.48,24.84,24.07,24.00,18.72.ESI-HRMS m / z calcd for C 39 H 41 NO9SNa + 722.2400, found 722.2408[M+Na] + HPLC purity 95%.

[0098] Example 4

[0099] Preparation of (3R,6R,9S,11R,11aR)-N-(4-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)butyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA4):

[0100]

[0101] Compound 5 (100 mg, 0.33 mmol) was dissolved in 10 mL of DMF in a 50 mL single-necked flask. HATU (152.9 mg, 0.4 mmol) and DIPEA (86.6 mg, 0.66 mmol) were added, and the mixture was stirred for half an hour under an inert atmosphere. Then, compound 11d (n = 4, 145.3 mg, 0.33 mmol) was added, and the mixture was stirred overnight at room temperature. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was evaporated to dryness and mixed. The mixture was then purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 85 mg of yellow solid compound 12c, with a yield of 36.1%.

[0102] 11H NMR (400 MHz, Methanol-d4) δ 7.67 (d, J = 8.9 Hz, 2H), 7.41 (d, J = 8.7 Hz, 1H), 7.28 (d, J = 2.4 Hz, 1H), 7.19 (d, J = 8.7 Hz, 2H), 6.87 (dd, J = 8.8, 2.2 Hz, 1H), 6.75 (d, J = 8.9 Hz, 2H), 6.64 (d, J = 8.7 Hz, 2H), 5.73 (s, 1H), 3.94 (t, J = 6.2 Hz, 2H), 3.24 (t, J = 6.9 Hz, 2H), 2.24 (ddd, J = 14.6, 13.0, 3.9 Hz, 1H), 2.14 (dd, J = 13.0, 6.4 Hz, 1H), 2.05–1.98 (m, 1H), 1.89 (ddp, J = 13.6, 10.0, 3.5 Hz, 2H), 1.75 (p, J = 6.5, 6.0 Hz, 2H), 1.68 (s, 3H), 1.64 (d, J = 4.8 Hz, 1H), 1.48–1.42 (m, 1H), 1.39 (dd, J = 11.1, 5.6 Hz, 1H), 1.35 (s, 2H), 1.31 (d, J = 9.5 Hz, 2H), 1.29–1.20 (m, 1H), 1.08 (qd, J = 13.2, 2.9 Hz, 2H), 0.95 (d, J = 6.3 Hz, 1H), 0.90 (d, J = 6.3 Hz, 3H). 13 13C NMR (101 MHz, CD3OD) δ 194.14, 174.52, 163.49, 157.81, 155.38, 142.46, 140.04, 132.97, 132.13, 130.03, 129.88, 124.68, 123.41, 115.14, 114.69, 113.99, 113.94, 106.59, 103.61, 97.41, 87.68, 86.39, 67.51, 51.32, 38.25, 36.67, 36.41, 32.01, 26.13, 25.69, 25.48, 24.93, 24.07, 24.03, 18.75. ESI-HRMS m / z calcd for C 40 H 43 NO9SNa + 736.2556, found 736.2558 [M+Na] + . HPLC purity 99%.

[0103] Example 5

[0104] Preparation of (3R,6R,9S,11R,11aR)-N-(6-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)hexyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxazo[3,4-d]isobenzofuran-9-carboxamide (RA6):

[0105]

[0106] Compound 5 (100 mg, 0.33 mmol) was placed in a 50 mL single-necked flask, dissolved in 10 mL of DMF, and HATU (152.9 mg, 0.4 mmol) and DIPEA (86.6 mg, 0.66 mmol) were added. The mixture was stirred for half an hour under an inert atmosphere, and then compound 11c (n = 6, 154.7 mg, 0.33 mmol) was added. The mixture was stirred overnight at room temperature. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was evaporated to dryness and mixed. The mixture was then purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 78 mg of a yellow solid compound 12 days, with a yield of 31.9%.

[0107] 11H NMR (400 MHz, Acetone-d6) δ 7.67 (d, J = 8.8 Hz, 2H), 7.39 (d, J = 8.8 Hz, 1H), 7.26 (d, J = 2.3 Hz, 1H), 7.19 (d, J = 8.6 Hz, 2H), 6.86 (dd, J = 8.8, 2.3 Hz, 1H), 6.76 (d, J = 8.9 Hz, 2H), 6.63 (d, J = 8.6 Hz, 2H), 5.73 (s, 1H), 3.91 (t, J = 6.4 Hz, 2H), 3.18 (t, J = 7.0 Hz, 2H), 2.24 (ddd, J = 14.6, 13.0, 3.9 Hz, 1H), 2.13 (dd, J = 13.0, 6.3 Hz, 1H), 2.01 (dt, J = 14.5, 3.9 Hz, 1H), 1.88 (dddd, J = 16.3, 9.3, 7.3, 3.6 Hz, 2H), 1.71 (q, J = 6.9 Hz, 2H), 1.66 (s, 3H), 1.51 (q, J = 6.6 Hz, 2H), 1.44 (d, J = 8.6 Hz, 2H), 1.39 (dd, J = 11.7, 6.8 Hz, 3H), 1.34 (s, 3H), 1.32 (d, J = 8.6 Hz, 1H), 1.30–1.20 (m, 1H), 1.08 (qd, J = 13.0, 11.9, 3.6 Hz, 2H), 0.95 (td, J = 12.4, 11.8, 2.5 Hz, 1H), 0.89 (d, J = 6.3 Hz, 3H). 13 13C NMR (101 MHz, CD3OD) δ 192.94, 173.14, 162.40, 156.58, 154.14, 141.11, 138.77, 131.70, 130.88, 128.73, 128.70, 128.64, 123.41, 122.12, 113.88, 113.42, 112.67, 105.31, 102.35, 96.15, 86.42, 85.13, 66.58, 50.06, 37.26, 35.41, 35.20, 30.77, 27.76, 27.33, 25.02, 24.21, 24.06, 23.65, 22.81, 22.75, 17.48. ESI-HRMS m / z calcd for C 42 H 47 NO9SNa + 764.2869, found 764.2861 [M+Na] + .. HPLC purity 97%.

[0108] Example 6

[0109] Preparation of (3R,5R)-N-(3-(4-(6-hydroxy-2-(4-hydroxyphenyl)benzo[b]thiophene-3-carbonyl)phenoxy)propyl)adamantane-1-carboxamide (RAdam):

[0110]

[0111] 1-Adamantanecarboxylic acid (25.8 mg, 0.14 mmol) was dissolved in 5 mL of DMF in a 25 mL single-necked flask. HATU (65.26 mg, 0.17 mmol) and DIPEA (37 mg, 0.28 mmol) were added, and the mixture was stirred for half an hour under an inert atmosphere. Then, compound 11a (n = 3, 60 mg, 0.14 mmol) was added, and the mixture was stirred overnight at room temperature. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was evaporated to dryness and mixed. The mixture was then purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 55 mg of a yellow solid compound, with a yield of 67.5%.

[0112] 1 H NMR (400MHz, Methanol-d4) δ7.71(d,J=8.5Hz,2H),7.40(d,J=8.8Hz,1H),7.28(d,J=2.2Hz,1H),7.20(d,J=8.3Hz,2H),6.87(dd,J=8.8,2.2 Hz,1H),6.82(d,J=8.6Hz,2H),6.65(d,J=8.3Hz,2H),3.33(s,4H),2.00(s,3H),1.94(t,J=6.4Hz,2H),1.84(s,6H),1.75(q,J=12.3Hz,6H). 13 CNMR(101MHz,CD3OD)δ194.28,179.60,163.48,157.83,155.38,142.38,140.03,132.93,132.10,130.13,129.95,1 29.88,124.67,123.30,115.10,114.64,113.93,106.51,65.86,40.39,38.79,36.19,36.16,28.64,28.23.ESI-HRMS m / zcalcd for C 35 H 35 NO5SNa + 604.2134, found 604.2134[M+Na] +HPLC purity 99%.

[0113] Example 7

[0114] Preparation of (3R,6R,9S,11R,11aR)-N-(3-((6-acetyl-8-cyclopentyl-5-methyl-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidin-2-yl)amino)propyl)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxacyclopropane[3,4-d]isobenzofuran-9-carboxamide (PA):

[0115]

[0116] Compound 4 (78.2 mg, 0.26 mmol) was dissolved in 10 mL of DMF in a 50 mL single-necked flask. EDCI (60.4 mg, 0.32 mmol), HOBT (42.6 mg, 0.32 mmol), and triethylamine (53.0 mg, 0.52 mmol) were added. The mixture was stirred under an inert atmosphere for half an hour. Then, compound 16 (90.0 mg, 0.26 mmol) was added, and the mixture was stirred at room temperature for 4 hours. After confirming the reaction was complete by TLC, the mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the organic phase was evaporated to dryness and then mixed. The mixture was purified by silica gel column chromatography (eluent ratio v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 81 mg of white solid compound 17, with a yield of 49.9%.

[0117] 1 H NMR(400MHz,Chloroform-d)δ8.71(d,J=74.1Hz,1H),7.95(s,0H),7.19(s,0H),5.94–5 .80(m,1H),5.75(s,1H),3.69–3.25(m,4H),2.53(s,3H),2.33(s,3H),2.28(dd,J=12.4, 6.5Hz,2H),2.14–1.96(m,5H),1.79(d,J=4.1Hz,9H),1.67(s,2H),1.53(h,J=5.7,4.1H z,2H),1.47(s,3H),1.42–1.28(m,1H),1.18(s,1H),1.01(s,2H),0.97(d,J=6.3Hz,3H). 13C NMR (101MHz, CDCl3) δ203.03,161.69,155.75,104.02,97.42,86.70,51.18,48.31,37 .03,36.99,32.32,31.59,28.05,26.06,26.00,25.29,24.45,19.79,13.94.ESI-HRMS m / z calcd for C 33 H 46 N5O7 + 624.3397, found 624.3402[M+H] + HPLC purity 98%.

[0118] Example 8

[0119] Preparation of N1-hydroxy-N8-(4-(((3R,6R,9S,11R,11aR)-3,6,9-trimethyloctahydro-3H,11H-3,11-epoxy[1,2]dioxane[3,4-d]isobenzofuran-9-carboxamide)butamido)phenyl)octadiamide (SA):

[0120]

[0121] Hydroxylamine hydrochloride (377.8 mg, 5.44 mmol) was dissolved in 10 mL of methanol, and NaOH (249.0 mg, 6.23 mmol) was added. The mixture was stirred at 40 °C for 20 min, and then the reaction mixture was cooled to 0 °C and filtered. At 0 °C, the filtrate was slowly added dropwise to a solution of compound 25 (100 mg, 0.16 mmol) in THF (10 mL), and the reaction was allowed to proceed at room temperature for 1 h. After the reaction was complete, the solvent was concentrated by vacuum distillation, and the solid was dissolved in water. The pH was adjusted to 7 with 2 mol / L HCl, and the solid was obtained by filtration. The solid was purified by silica gel column chromatography (eluent ratio v / v). 二氯甲烷 / v 甲醇 =100:1-10:1), yielding 50 mg of white solid compound 26, with a yield of 48.5%.

[0122] 1H NMR (400MHz, DMSO-d6) δ10.33(s,1H),9.84(d,J=8.2Hz,1H),9.78(s,1H),8.65(s,1H),8.01(s,1H),7.49(d ,J=3.3Hz,4H),5.76(d,J=22.6Hz,1H),3.10(q,J=6.3Hz,2H),2.27(dt,J=14.4,7.3Hz,4H),2.04(dd,J=11.7 ,5.6Hz,2H),1.93(t,J=7.4Hz,2H),1.75(q,J=6.9Hz,3H),1.56(s,4H),1.49(d,J=7.2Hz,2H),1.40(s,1H),1 .35(d,J=7.3Hz,4H),1.31–1.24(m,6H),1.23(d,J=5.4Hz,3H),0.92(d,J=6.0Hz,2H),0.86(d,J=6.3Hz,3H). 13 C NMR(101MHz,CD3OD_SPE)δ177.17,173.03,172.41,171.55,134.65,134.62,120.19,103.10,96.97,86.41,86.04,49.82,38.49,36.6 6,36.59,36.41,33.86,32.30,32.25,31.36,28.51,28.43,25.35,25.19,24.64,24.32,24.22,22.31,20.83,18.75,13.04.ESI-HRMS m / z calcd for C 33 H 48 N4O9Na + 667.3319, found 667.3323 [M+Na] + HPLC purity 98%.

[0123] Example 9 Cell Viability Test

[0124] MCF-7 cells were cultured in DMEM liquid medium containing 10% fetal bovine serum and phenol red. When the cell density reached 80%–90%, the cells were digested, and the cell suspension was seeded into 96-well cell culture plates using DMEM medium without phenol red and containing 10% FBS. After complete cell attachment, the original culture medium was discarded, and 100 μL of a compound solution prepared in fresh DMEM medium containing 10% FBS was added to each well, with a compound concentration gradient of 1 × 10⁻⁶. -7.5 M, 1×10 -7 M, 1×10 -6.5 M, 1×10-6 M, 1×10 - 5.5 M, 1×10 -5 M, 1×10 -4.5 M, 1×10 -4 M. After 4 days of drug treatment and culture, remove the culture plate, aspirate the culture medium, add 100 μL of CCK8 working solution to each well, and incubate at 37℃ in a 5% CO2 incubator for 1.5–2 hours. Read the plate on a microplate reader, select 450 nm as the reference wavelength, analyze the experimental results, and calculate the IC50. 50 The results are shown in Table 1.

[0125] Table 1. Effects of the target compound on the viability of MCF-7 breast cancer cells.

[0126]

[0127]

[0128] a IC 50 It is the mean ± standard deviation of at least three independent experiments.

[0129] This embodiment evaluated the effects of the seven compounds listed in Table 1 on MCF-7 cell viability. Compounds RA2, RA3, RA4, RA6, RAdam, PA, and SA, all tagged with artemisinin, had some effect on MCF-7 cell viability, with compound RA3 showing the greatest impact. The IC50 of this compound was [not specified in the original text]. 50 The value is 2.28 ± 0.80 μM.

[0130] Example 10: ER Degradation Activity Assay

[0131] To demonstrate that the hydrophobic-tagged benzothiophene derivatives synthesized in this invention possess the ability to degrade estrogen receptor (ERα), and to analyze the effect of chain length on protein degradation activity, the structural formula of the hydrophobic-tagged benzothiophene derivatives is as follows:

[0132]

[0133] In this embodiment, MCF-7 was treated with raloxifene, artemisinin, and four compounds (RA2, RA3, RA4, and RA6) (10 μM) for 24 h. All proteins were then extracted, and the effects of these compounds on ERα degradation were analyzed by Western blotting, with comparisons made with raloxifene. The results are as follows: Figure 1 As shown.

[0134] pass Figure 1It can be concluded that the series of compounds of this invention have good ERα downregulation activity. All four compounds significantly reduced ERα levels, with compound RA3 exhibiting the highest efficacy, reaching a degradation efficiency of 73.1%. Notably, neither raloxifene nor artemisinin with d-ring shrinkage alone significantly reduced ERα levels, demonstrating the necessity of the conjugated structure in effective degradation. This result also shows that the ERα degradation activity of the compounds is related to their side chain length; when the chain length increases to a certain extent, the degradation activity of the target product decreases. Therefore, an appropriate side chain length is also important for ERα degradation activity. By comparing compounds with adamantyl tags and artemisinin-based tags, it was found that introducing an artemisinin tag can indeed improve the ERα degradation activity of the compounds, verifying the feasibility of artemisinin-based tags as hydrophobic tags.

[0135] Example 11: CDK6 Degradation Activity Assay

[0136] To demonstrate the ability of the synthesized hydrophobically tagged methylpyridinidine compound to degrade cyclin-dependent kinase 6 (CDK6), MCF-7 was treated with compound PA at concentrations of 0.1 μM, 1.0 μM, and 10 μM for 24 h. All proteins were then extracted, and the effect of the compound on CDK6 degradation was analyzed by Western blotting. The structural formula of the hydrophobically tagged methylpyridinidine compound is as follows:

[0137]

[0138] The results are as follows Figure 2 As shown, PA significantly reduced CDK6 levels in MCF-7 cells, with 10 μM PA inducing CDK6 degradation by 73%.

[0139] Example 12: Determination of HDAC 6 degradation activity

[0140] To demonstrate that the synthesized hydrophobic succinyl aniline isohydroxamic acid compounds have the ability to degrade histone deacetylase 6 (HDAC 6), MCF-7 was treated with compound SA at concentrations of 0.1 μM, 1.0 μM, and 10 μM for 24 h. All proteins were then extracted, and the effect of the compounds on the degradation of HDAC 6 was analyzed by Western blotting.

[0141] The results are as follows Figure 3 As shown, SA significantly reduced HDAC 6 levels in MCF-7 cells, and 10 μM SA induced CDK6 degradation by 69%.

[0142] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A targeted protein degrader, characterized in that, The targeted protein degrader has a structure as shown in formula (II), (III), or (IV): Where n is any integer from 1 to 10; Where n is any integer from 1 to 10; Where n is any integer from 1 to 10.

2. A method for synthesizing the targeted protein degrader as described in claim 1, characterized in that, Includes the following steps: 1) Synthesis of artemisinin analog compound 5; the structural formula of compound 5 is shown below: 2) Synthesis of target protein ligands with linkers, and then amidation reaction of the artemisinin analogue described in step 1) with the target protein ligand to obtain a targeted protein degrading agent; the target protein ligand is any one of benzothiophene compounds, methylpyridinidine compounds, and octanoylaniline isohydroxamic acid compounds.

3. The method according to claim 2, characterized in that, Step 1) The synthesis of artemisinin analogues specifically includes the following steps: S1. Compound 1 was dissolved in tetrahydrofuran, cooled to 0°C, and boron trifluoride diethyl ether was added dropwise. The reaction was carried out for 24 hours. After the reaction was completed, the reaction was quenched with saturated sodium bicarbonate, extracted, dried, distilled, and purified to obtain compound 2. S2. Compound 2 was dissolved in carbon tetrachloride, and bromine was slowly added dropwise at 0°C with stirring. After the reaction was completed, diethyl ether was added for dilution, sodium thiosulfate was added for quenching, the mixture was dried, and the mixture was distilled under reduced pressure to obtain compound 3. S3. Dissolve compound 3 in dichloromethane, add triethylamine, stir until the reaction is complete, neutralize excess triethylamine, wash, dry, filter, concentrate, and purify to obtain compound 4; S4. Compound 4 was dissolved in a 1,4-dioxane solution, an aqueous solution containing aminosulfonic acid was added, and the mixture was stirred overnight at 0°C. NaClO2 and water were added, and the mixture was stirred. Na2SO3 was added, and the mixture was diluted, extracted, washed, dried, and evaporated to obtain compound 5. The structural formulas of compounds 1, 2, 3, and 4 are shown below:

4. The method according to claim 2, characterized in that, Step 2) involves the synthesis of the linker-conjugated target protein ligand, specifically including the following steps: (1) When the target protein ligand is a benzothiophene compound, the method for synthesizing the target protein degrading agent includes the following steps: a) 4-Acetylbenzoic acid was stirred with oxalyl chloride at room temperature to give an acyl chloride intermediate. The intermediate reacted with compound 7 and anhydrous aluminum chloride to give compound 8. Compound 8 was dissolved in anoxic ethanol / water solution, and sodium acetate was added and stirred at 100°C to give compound 9. Compound 9 was reacted with (n-bromonalkyl)carbamate tert-butyl ester to give compound 10. Boron tribromide was used to remove methyl and Boc groups to give compound 11. b) Using HATU as a catalyst and DIPEA as a base, the compound 11 and the compound 5 of claim 2 are subjected to an amidation reaction in DMF solvent; The structural formulas of compounds 7, 8, 9, 10, and 11 are as follows: Where n is 1 to 10; (2) When the target protein ligand is a methylpyridinidine compound, the method for synthesizing the target protein degrading agent includes the following steps: c) Compound 13 and compound 14 were mixed and reacted under argon, DIPEA and DMSO, then extracted, dried, filtered and concentrated to obtain compound 15; d) Dissolve compound 15 in dichloromethane, add TFA dropwise at 0°C, stir, extract, wash, dry, filter and concentrate to obtain compound 16; e) Dissolve compound 5 in DMF, add EDCI, HOBT and triethylamine, stir under inert gas, add compound 16, stir at room temperature, after the reaction is complete, extract, dry and purify; The structural formulas of compounds 13, 14, 15, and 16 are shown below: (3) When the target protein ligand is an octanoyl aniline isohydroxamic acid compound, the method for synthesizing the target protein degrading agent includes the following steps: f) Compound 18 was reacted with compound 19 at room temperature to give compound 20; g) Remove the Boc group from compound 20 to obtain compound 21; h) Compound 21 and compound 22 are subjected to an amide condensation reaction to obtain compound 23; i) Remove the Boc group from compound 23 to obtain compound 24; j) Compound 24 and compound 5 are subjected to an amide condensation reaction to obtain compound 25; k) Hydroxylamine hydrochloride is reacted with sodium hydroxide to generate hydroxylamine, and the hydroxylamine is reacted with compound 25 under alkaline conditions; The structural formulas of compounds 18, 19, 20, 21, 22, 23, 24, and 25 are shown below:

5. A pharmaceutical composition, characterized in that, It includes the targeted protein degrader as described in claim 1 or the targeted protein degrader synthesized according to any one of claims 2-4.

6. The pharmaceutical composition according to claim 5, characterized in that, This also includes pharmaceutically acceptable carriers and pharmaceutically acceptable dosage forms.

7. The use of the targeted protein degrading agent as described in claim 1 or the targeted protein degrading agent synthesized according to any one of claims 2-4 in the preparation of a medicament for targeting and degrading hormone receptors.

8. The use of the targeted protein degrading agent as described in claim 1 or the targeted protein degrading agent synthesized according to any one of claims 2-4 in the preparation of a medicament for treating breast cancer.

Images