PROTAC compound targeting PI3Kalpha as well as preparation and application of PROTAC compound

Abstract

The invention belongs to the field of medicine, and provides a PROTAC compound targeting PI3Kalpha and preparation and application thereof. The PROTAC compound is selected from a compound as shown in a formula (I) or pharmaceutically acceptable salt, hydrate, solvate or prodrug thereof. The compound realizes specific degradation of PI3Kalpha protein instead of pure enzyme activity inhibition by combining an allosteric site of PI3Kalpha and E3 ligase at the same time. The compound still keeps efficient degradation activity on clinically common drug-resistant mutants, and the problem that a traditional small-molecule inhibitor is prone to drug resistance is effectively solved. The structure of the formula (I) is shown in the specification.

Description

Technical Field

[0001] This disclosure relates to the pharmaceutical field, and in particular to PROTAC compounds targeting PI3Kα, their preparation, and applications. Background Technology

[0002] Phosphatidylinositol 3-kinase α (PI3Kα), an important member of the phosphatidylinositol 3-kinase family, is a key signaling molecule that regulates cell growth, proliferation, differentiation, and apoptosis. Mutations or abnormal activation of its encoding gene can lead to disruption of cell signaling pathways, thereby inducing the occurrence and development of tumors. It is closely related to the pathological process of various malignant tumors such as ovarian cancer, breast cancer, and lung cancer, and has become one of the core targets for anti-tumor drug development.

[0003] The development of PI3Kα inhibitors is a hot research topic in the field of anti-tumor therapy. Traditional PI3Kα orthoform inhibitors exert their effects by directly binding to the active site of the kinase, but they are prone to causing serious side effects such as hyperglycemia in clinical applications, and their selectivity for wild-type and mutant PI3Kα is poor, limiting their clinical application value. Against this backdrop, PI3Kα allosteric inhibitors, with their mechanism of action of binding to the inactive site of the kinase, are expected to fundamentally avoid the hyperglycemic side effects of orthoform inhibitors, becoming a research direction for the next generation of PI3Kα inhibitors. However, currently reported PI3Kα allosteric inhibitors still suffer from insufficient selectivity for wild-type and mutant PI3Kα, and simultaneously improving their efficacy and target selectivity has become a technical challenge that urgently needs to be solved in this field.

[0004] Protein degradation-targeting chimeras (PROTACs) are bifunctional small molecule drugs based on the ubiquitin-proteasome system. They consist of a target protein-binding ligand, a linker, and an E3 ubiquitin ligase-binding ligand. They specifically degrade target proteins through a catalytic degradation mechanism. Compared to traditional small molecule inhibitors, they exhibit significant advantages in addressing target inaccessibility and overcoming drug resistance, providing a novel approach for anti-tumor drug development. While there are reports of PROTAC molecules constructed based on PI3Kα ortho-inhibitors, these molecules rely on the target protein binding structure of the ortho-inhibitor, making it difficult to avoid the hyperglycemic side effects associated with ortho-inhibitors in subsequent applications. Furthermore, no PROTAC molecules based on PI3Kα allosteric inhibitors have been developed or reported.

[0005] Ovarian cancer, a common malignant tumor of the female reproductive system, is frequently associated with PI3Kα mutations, which are a significant contributing factor to its occurrence, progression, and drug resistance. Therefore, the development of targeted drugs against PI3Kα mutants is of great clinical importance for the treatment of ovarian cancer. In summary, the development of PROTAC molecules based on PI3Kα allosteric inhibitors can leverage the advantages of allosteric inhibitors—such as reduced side effects and high targeting—while also utilizing the catalytic degradation mechanism of PROTACs to efficiently eliminate PI3Kα mutants. This provides a novel drug candidate for the treatment of PI3Kα-mutant ovarian cancer, fills a research gap in the field, and possesses significant theoretical research value and promising clinical application prospects. Summary of the Invention

[0006] This disclosure provides PROTAC compounds targeting PI3Kα, their preparation and applications, to at least solve the above-mentioned technical problems existing in the prior art.

[0007] According to a first aspect of this disclosure, a PROTAC compound targeting PI3Kα is provided, said PROTAC compound being selected from compounds of formula (I) or pharmaceutically acceptable salts, hydrates, solvates or prodrugs thereof, wherein the compound of formula (I) has the following general structural formula:

[0008] (I); Where W is selected from C or O; x = 2~4; y = 1~3; z = 3~10.

[0009] Specifically, in the compound shown in formula (I), the structure on the left is a highly specific PI3Kα allosteric inhibitor (containing a difluorobenzofuran ring and a chiral trifluoromethylaminourea structure). This disclosure is the first to use an allosteric inhibitor skeleton as a target for PROTAC. Allosteric site binding typically exhibits higher subtype selectivity, effectively avoiding inhibition of PI3Kβ / δ / γ, thus reducing the off-target toxicity of traditional PROTACs from the source. Allosteric inhibitors usually have shallow binding pockets, and it is generally believed that they are difficult to withstand the introduction of a linker (which would disrupt the binding mode). This disclosure successfully integrates the allosteric target with PROTAC technology, overcoming technological bias. The linker structure is -W-(CH2). x -NH-CO-(CH2) y -CO-NH-(CH2) zThe specification specifies that W is selected from C or O, x=2~4, y=1~3, and z=3~10. This linker chain is the core of PROTAC druggability, containing two amide bonds (-NH-CO-), forming a locally rigid plane while retaining the flexibility of the methylene group. This combination of rigidity and flexibility is designed to accommodate minor conformational changes in the protein after allosteric binding. Furthermore, this disclosure does not use an unrestricted straight-chain alkyl group, but rather selects a golden range: x=2~4 ensures an appropriate distance extending from the target, without interfering with allosteric binding; z=3~10 precisely matches the steric hindrance after binding of the CRBN ligand (an E3 ligase ligand that efficiently recruits CRBN E3 ligase for efficient degradation of PI3Kα) to the E3 ligase. Beyond these ranges, the compound may result in poor cell membrane permeability due to its excessive molecular size, or an inability to form an effective ternary complex. Furthermore, the efficacy of PROTAC is highly dependent on the combination of the allosteric PI3Kα target and the CRBN ligand (a phthalimide-like structure on the right side, such as a thalidomide derivative). The CRBN system is generally highly expressed in tumor cells, and when combined with the highly selective allosteric target, it achieves the advantages of precise targeting and broad-spectrum degradation.

[0010] In one embodiment, formula (I) is selected from compounds with the following structural formulas: , , , , , , , , , , .

[0011] According to a second aspect of this disclosure, a pharmaceutical composition is provided comprising the aforementioned PROTAC compound and at least one pharmaceutically acceptable carrier, excipient, or diluent.

[0012] According to a third aspect of this disclosure, a method for preparing the aforementioned PROTAC compound targeting PI3Kα is provided, comprising the following steps: S1: Preparation of intermediates for PI3Kα allosteric inhibitory heads; S2: Starting from 2-(2,6-dioxopiperidin-3-yl)-4-fluoroisoindoline-1,3-dione, reacting with NH2-(CH2) z -NHBoc undergoes a nucleophilic substitution reaction, where z = 3~10, to give an N-Boc protected CRBN ligand-linker intermediate; after removing the Boc protecting group, it reacts with... An acylation reaction is carried out, where y = 1~3, to obtain a CRBN ligand-linking chain intermediate; S3: Combine the PI3Kα allosteric repressor head intermediate obtained in step S1 with NH2-(CH2)2-W-(CH2). x -NHBoc undergoes a nucleophilic substitution reaction, wherein W is selected from C or O, and x = 2~4, to obtain an amino-substituted urea intermediate; the amino-substituted urea intermediate is then subjected to an amidation reaction with the CRBN ligand-linking chain intermediate obtained in step S2 under the action of a condensing agent and a base to obtain the PROTAC compound targeting PI3Kα.

[0013] In one embodiment, step S1, which involves preparing the PI3Kα allosteric inhibitory head intermediate, includes: using 1-(3,5-difluoro-2-hydroxyphenyl)ethyl-1-one as a starting material, and subjecting it to alkylation, cyclization, imidization, trifluoromethylation, deprotection, and ureation reactions to obtain the PI3Kα allosteric inhibitory head intermediate.

[0014] Specifically, step S1, the preparation of the PI3Kα allosteric suppressor head intermediate, includes: using 1-(3,5-difluoro-2-hydroxyphenyl)ethyl-1-one as the starting material, performing an alkylation reaction with an alkylating agent in the presence of a base and a catalyst; subjecting the obtained product to a cyclization reaction in the presence of an acid catalyst to obtain a benzofuran carboxaldehyde intermediate; reacting the benzofuran carboxaldehyde intermediate with an imidizing agent to obtain an imine intermediate; subjecting the imine intermediate to a trifluoromethylating agent with a trifluoromethylating agent in the presence of an activator; removing the protecting group from the obtained product under the action of a deprotecting agent to obtain a free amino intermediate; and reacting the free amino intermediate with a ureating agent to obtain the PI3Kα allosteric suppressor head intermediate.

[0015] More specifically, the alkylating agent is 1-bromo-2,2-diethoxyethane, the base is K2CO3, and the catalyst is NaI; the alkylation reaction is carried out in DMF (N,N-dimethylformamide) at 120°C for 8 hours.

[0016] More specifically, the acid catalyst is AcOH (acetic acid); the cyclization reaction is carried out in DMF at 120°C for 8 hours.

[0017] More specifically, the imidizing agent is dimethyl sulfoxide methyleneamine; the imidization reaction is carried out in THF (tetrahydrofuran) at 60°C for 6 hours with K2CO3 as the base.

[0018] More specifically, the trifluoromethylating agent is TMSCF3 (trifluoromethyltrimethylsilane), and the activator is TBAA (tert-butyl acetoacetate); the trifluoromethylation reaction is carried out in THF at -20°C for 2 hours.

[0019] More specifically, the deprotection reagent is HCl-EtOAc (saturated ethyl hydrogen chloride solution); the deprotection reaction is carried out at room temperature for 2 hours.

[0020] More specifically, the ureating agent is phenyl 2-chloropyrimidin-4-ylcarbamate; the ureation reaction is carried out in pyridine at 80°C for 5 hours.

[0021] In one embodiment, the nucleophilic substitution reaction in step S2 is carried out in DIPEA (diisopropylethylamine) and NMP (N-methylpyrrolidone) at 85-95°C for 6-10 hours; the Boc protecting group removal reaction is carried out in TFA (trifluoroacetic acid) and DCM (dichloromethane) at 8-12°C for 1-1.5 hours; and the acylation reaction is carried out in DIPEA and DMF at room temperature for 3-5 hours.

[0022] In one embodiment, the condensing agent in step S3 is selected from any one of HATU (O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate), EDCl (1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride), HOBt (1-hydroxybenzotriazole), DCC (N,N'-dicyclohexylcarbodiimide), and PyBOP (benzotriazol-1-yl-oxo-tripyrrolidinylphosphine hexafluorophosphate), and the base is selected from any one of DIPEA, triethylamine, and N-methylmorpholine.

[0023] In one embodiment, the nucleophilic substitution reaction in step S3 is carried out at 110-130°C for 7-9 hours in DIPEA and nBuOH (n-butanol); the amidation reaction is carried out at room temperature for 15-17 hours in the presence of HATU and DIPEA.

[0024] According to the fourth aspect of this disclosure, the use of the aforementioned PROTAC compound in the preparation of a medicament for treating diseases related to PI3Kα abnormalities is provided.

[0025] In one possible implementation, the disease includes any one of breast cancer, colorectal cancer, endometrial cancer, and ovarian cancer.

[0026] According to one possible implementation of this disclosure, at least the following beneficial effects are achieved: 1. The PROTAC compound disclosed herein achieves specific degradation of PI3Kα protein by simultaneously binding to the allosteric site of PI3Kα and the E3 ligase, rather than simply inhibiting enzyme activity. It maintains highly efficient degradation activity against clinically common drug-resistant mutants (such as H1047R, E545K, and E542K), effectively solving the problem of drug resistance easily generated by traditional small molecule inhibitors. This compound degrades the target protein through a catalytic mechanism, achieving a sustained decrease in protein levels with a single dose. Compared to traditional inhibitors, it has more durable pharmacokinetic effects, potentially reducing dosing frequency and improving patient adherence.

[0027] 2. This disclosure employs a PI3Kα allosteric inhibitor as the targeting module, which significantly improves selectivity for PI3Kα compared to ATP-competitive inhibitors, avoiding inhibition of other PI3Kα isoforms. This reduces side effects such as metabolic disturbances and immunosuppression caused by inhibiting other isoforms, thus expanding the therapeutic window. Furthermore, the modular design of the PI3Kα allosteric inhibitor + linker chain + CRBN ligase ligand allows for independent synthesis and optimization of each fragment. A clear preparation method is also provided, facilitating further optimization of the compound's pharmacokinetic properties by adjusting parameters such as linker chain length and hydrophilicity / hydrophobicity.

[0028] 3. Abnormal activation of PI3Kα is prevalent in various malignant tumors, including breast cancer, colorectal cancer, and endometrial cancer. The PROTAC compound disclosed herein provides a novel treatment strategy for these diseases. It can be used as a monotherapy or in combination with immune checkpoint inhibitors and chemotherapy drugs, and is expected to significantly improve anti-tumor efficacy.

[0029] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0030] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0031] Figure 1 A schematic diagram of the chemical reaction formula for preparing a PROTAC compound targeting PI3Kα is shown in a specific embodiment of this disclosure; Figure 2The diagram illustrates the antiproliferative activity of the PROTAC compounds of Examples 1-8 of this disclosure against PI3Kα mutant SKOV-3 H1047R tumor cells at three concentrations of 1 μM, 3 μM, and 10 μM; where C3, C4, C5, C6, C7, C8, C9, and C10 represent the PROTAC compounds of Examples 1-8, respectively. Detailed Implementation

[0032] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0033] This disclosure provides a PROTAC compound targeting PI3Kα, selected from compounds of formula (I) or their pharmaceutically acceptable salts, hydrates, solvates, or prodrugs, wherein the compound of formula (I) has the following general structural formula: (I); Where W is selected from C or O; x = 2~4; y = 1~3; z = 3~10.

[0034] The schematic diagram of the preparation process of the above PROTAC compound is shown below. Figure 1 As shown, the specific steps include the following: S1: Preparation of intermediates for PI3Kα allosteric inhibitory heads; Specifically, the reaction involved: using 1-(3,5-difluoro-2-hydroxyphenyl)ethyl-1-one (15 g, 1.0 equiv) as the starting material, and alkylating agent 1-bromo-2,2-diethoxyethane (18.89 g, 1.1 equiv) in the presence of base K2CO3 (24.09 g, 2.0 equiv) and catalyst NaI (1.31 g, 0.1 equiv), the alkylation reaction was carried out in DMF (100 mL) at 120 °C for 8 hours (see [link to DMF]). Figure 1 Step 1); the resulting product was cyclized in DMF (N,N-dimethylformamide) (4.6 mL) at 120 °C for 8 hours in the presence of the acid catalyst AcOH (acetic acid) (100 mL) to give the benzofuran carboxaldehyde intermediate (see Step 1). Figure 1Step 2); Benzofuran formaldehyde intermediate (1.05 g, 1.0 equiv) and imidizing reagent dimethyl sulfoxide methyleneamine (713 mg, 1.1 equiv) were subjected to imidization reaction in THF (tetrahydrofuran) (20 mL) with K2CO3 (1.11 g, 1.5 equiv) as base at 60 °C for 6 hours to obtain imine intermediate (see Step 2). Figure 1 Step 3); The imine intermediate (2.11 g, 1.0 equiv) and the trifluoromethylating agent TMSCF3 (trifluoromethyltrimethylsilane) (3.01 g, 3.0 equiv) were subjected to trifluoromethylation in THF (30 mL) at -20 °C for 2 hours in the presence of activator TBAA (tert-butyl acetoacetate) (2.13 g, 1.0 equiv) (see Step 3). Figure 1 Step 4); the resulting product (1.67 g, 1.0 equiv) was reacted at room temperature (rt) for 2 hours with the deprotecting agent HCl-EtOAc (saturated ethyl hydrochloride solution) (5 mL) to remove the protecting group, yielding the free amino intermediate (see Step 4). Figure 1 Step 5); Under nitrogen protection, the free amino intermediate (600 mg, 1.0 equiv) and the ureating agent 2-chloropyrimidin-4-ylcarbamate (500 mg, 1.0 equiv) were ureated in pyridine (10 mL) at 80 °C for 5 hours (see Step 5). Figure 1 (Step 6) After the reaction was completed, the solvent was removed by vacuum concentration, diluted with ethyl acetate, and subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1) to obtain the PI3Kα allosteric inhibitor intermediate (white solid, 625 mg), with a yield of 74%.

[0035] S2: Starting from 2-(2,6-dioxopiperidin-3-yl)-4-fluoroisoindoline-1,3-dione, reacting with NH2-(CH2) z -NHBoc undergoes a nucleophilic substitution reaction, where z = 3~10, to give an N-Boc protected CRBN ligand-linking chain intermediate (see [link to relevant documentation]). Figure 1 Step 7); after removing the Boc protecting group, with An acylation reaction is performed, where y = 1~3, to obtain the CRBN ligand-linking chain intermediate (see...). Figure 1 Step 8); Specifically, the above nucleophilic substitution reaction was carried out in DIPEA (diisopropylethylamine) and NMP (N-methylpyrrolidone) at 90 °C for 8 hours; the Boc protecting group removal reaction was carried out in TFA (trifluoroacetic acid) and DCM (dichloromethane) at 10 °C for 1 hour; and the acylation reaction was carried out in DIPEA and DMF at room temperature (rt) for 4 hours.

[0036] S3: Combine the PI3Kα allosteric repressor head intermediate obtained in step S1 with NH2-(CH2)2-W-(CH2). x -NHBoc undergoes a nucleophilic substitution reaction, where W is selected from C or O, and x = 2~4, to give an amino-substituted urea intermediate (see [link to relevant documentation]). Figure 1 (Step 9); The amino-substituted urea intermediate and the CRBN ligand-linker intermediate obtained in step S2 are amidated in the presence of a condensing agent and a base to obtain a PROTAC compound targeting PI3Kα (see Step 9). Figure 1 Step 10).

[0037] Specifically, the above nucleophilic substitution reaction was carried out at 120 °C for 8 hours in DIPEA and nBuOH (n-butanol); the amidation reaction was carried out at room temperature (rt) for 16 hours in the presence of the condensing agent HATU (O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate) and the base DIPEA.

[0038] For more detailed synthesis methods of Steps 1 to 5 above, please refer to patents WO2022265993A1 and WO2024077036A1.

[0039] Steps 1 to 6 are general steps and will not be repeated in the following embodiments. Only the synthesis steps of Steps 7 to 10 will be described.

[0040] Example 1 This embodiment prepared a PROTAC compound targeting PI3Kα, abbreviated as C3-PROTAC, with the following structural formula: .

[0041] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (500 mg, 1.0 equiv.), N-Boc-1,3-propanediamine (347 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 468 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 253 mg of a yellow solid, yield 32%.

[0042] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (253 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The mixture was reacted at 10°C for 1 hour. After the reaction was complete, the reaction mixture was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (96 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 297 mg, 3.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The mixture was reacted at room temperature for 4 hours. After the reaction was complete, the mixture was diluted with a large amount of water, and the pH was adjusted to approximately 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 297 mg of a yellow solid, yield 87%.

[0043] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0044] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (104 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 10 mg of a yellow solid, yield 5%. This solid was C3-PROTAC.

[0045] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 43 H 47 F5N 10 O8,926.3527; Found:927.3600.

[0046] Example 2 In this embodiment, a PROTAC compound targeting PI3Kα, abbreviated as C4-PROTAC, was prepared, and its structural formula is as follows: .

[0047] The preparation method is as follows: Step 7: 2-(2,6-dioxadiazine-3-yl)-4-fluoroisoindoline-1,3-dione (1.0 g, 1.0 equiv.), N-Boc-1,4-butanediamine (750 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 936 mg, 1.2 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 851 mg of a yellow solid, yield 53%.

[0048] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (851 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (436 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 1.24 g, 5.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 636 mg of yellow solid, yield 75%.

[0049] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0050] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (127 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 21 mg of a yellow solid, yield 11%. This solid was C4-PROTAC.

[0051] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 44 H 49 F5N 10 O8, 941.3728; Found: 941.3730.

[0052] Example 3 In this embodiment, a PROTAC compound targeting PI3Kα, abbreviated as C5-PROTAC, was prepared, and its structural formula is as follows: .

[0053] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (500 mg, 1.0 equiv.), N-Boc-1,5-pentanediamine (403 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 468 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 336 mg of a yellow solid, yield 40%.

[0054] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (336 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (118 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 364 mg, 3.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 188 mg of yellow solid, yield 41%.

[0055] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0056] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (114 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 29 mg of a yellow solid, yield 15%. This solid was C5-PROTAC.

[0057] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 45 H 51 F5N 10 O8,955.3894; Found:954.3894.

[0058] Example 4 In this embodiment, a PROTAC compound targeting PI3Kα, abbreviated as C6-PROTAC, was prepared, and its structural formula is as follows: .

[0059] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (400 mg, 1.0 equiv.), N-Boc-1,6-hexanediamine (345 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 374 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~2:1) to give 237 mg of a yellow solid, yield 35%.

[0060] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (237 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The mixture was reacted at 10°C for 1 hour. After the reaction was complete, the reaction mixture was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (63 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 193 mg, 3.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The mixture was reacted at room temperature for 4 hours. After the reaction was complete, the mixture was diluted with a large amount of water, and the pH was adjusted to approximately 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 146 mg of a yellow solid, yield 60%.

[0061] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0062] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (117 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 30 mg of a yellow solid, yield 15%. This solid was C6-PROTAC.

[0063] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 46 H 53 F5N 10 O8, 968.3938; Found: 969.4010.

[0064] Example 5 In this embodiment, a PROTAC compound targeting PI3Kα, abbreviated as C7-PROTAC, was prepared, and its structural formula is as follows: .

[0065] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (400 mg, 1.0 equiv.), N-Boc-1,7-heptanediamine (367 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 374 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~2:1) to give 241 mg of a yellow solid, yield 34%.

[0066] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (241 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (78 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 241 mg, 3.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 203 mg of yellow solid, yield 65%.

[0067] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0068] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (120 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 24 mg of a yellow solid, yield 12%. This solid was C7-PROTAC.

[0069] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 47 H 55 F5N 10 O8,983.4197; Found:983.4180.

[0070] Example 6 In this embodiment, a PROTAC compound targeting PI3Kα, abbreviated as C8-PROTAC, was prepared, and its structural formula is as follows: .

[0071] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (1.0 g, 1.0 equiv.), N-Boc-1,8-octanediamine (923 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 936 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to give 935 mg of a yellow solid, yield 49%.

[0072] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (935 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (430 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 1.22 g, 5.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 680 mg of yellow solid, yield 70%.

[0073] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0074] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (124 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 18 mg of a yellow solid, yield 14%. This solid was C8-PROTAC.

[0075] The high-resolution mass spectrometry data of the above compounds are as follows: 1 H NMR (600MHz, d 6 -DMSO) δ 8.27 (s,2H), 7.55 (t, J = 7.8Hz, 1H), 7.21 (d, J = 8.4Hz, 1H), 7.05-7.08 (m, 3H),5.98 (q, J = 7.8Hz, 1H), 3.31 (s, 2H), 3.15-3.17 (m, 4H), 2.69-2.78 (m, 2H),2.33 (s, 3H), 2.20 (t, J = 7.8Hz, 4H), 2.10-2.15 (m, 1H), 1.86-1.91 (m, 2H),1.63-1.68 (m, 2H), 1.57-1.62 (m, 2H), 1.48-1.53 ​​(m, 4H), 1.30-1.42 (m, 17H),HRMS (ESI, m / z) [M+H] + Calculated for C 48 H 57 F5N 10 O8, 997.4354; Found: 997.4375.

[0076] Example 7 In this embodiment, a PROTAC compound targeting PI3Kα, abbreviated as C9-PROTAC, was prepared, and its structural formula is as follows: .

[0077] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (500 mg, 1.0 equiv.), N-Boc-1,9-nonanediamine (515 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 468 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~2:1) to give 510 mg of a yellow solid, yield 54%.

[0078] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (510 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (156 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 482 mg, 3.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 379 mg of a yellow solid, yield 58%.

[0079] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0080] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (127 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 23 mg of a yellow solid, yield 11%. This solid was C9-PROTAC.

[0081] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 49 H 59 F5N 10 O8, 1011.4510; Found: 1011.4512.

[0082] Example 8 This embodiment prepared a PROTAC compound targeting PI3Kα, abbreviated as C10-PROTAC, with the following structural formula: .

[0083] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (1.0 g, 1.0 equiv.), N-Boc-1,10-decanediamine (1.08 g, 1.1 equiv.), diisopropylethylamine (DIPEA, 936 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 715 mg of a yellow solid, yield 37%.

[0084] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (715 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (309 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 874 mg, 5.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 498 mg of yellow solid, yield 68%.

[0085] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 328 mg, 1.0 equiv.), N-Boc-1,6-propanediamine (337 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 504 mg, 5.0 equiv.), and n-butanol (nBuOH, 5 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 138 mg of a dark red viscous solid, with a yield of 29%.

[0086] Step 10: Dissolve the intermediate (120 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (130 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 78 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 26 mg of a yellow solid, yield 13%. This solid was C10-PROTAC.

[0087] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 50 H 61 F5N 10 O8, 1025.4667; Found: 1024.4701.

[0088] Example 9 In this embodiment, a PROTAC compound targeting PI3Kα was prepared, abbreviated as C4-PEG1-PROTAC, with the following structural formula: .

[0089] The preparation method is as follows: Step 7: 2-(2,6-dioxadiazine-3-yl)-4-fluoroisoindoline-1,3-dione (1.0 g, 1.0 equiv.), N-Boc-1,4-butanediamine (750 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 936 mg, 1.2 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 851 mg of a yellow solid, yield 53%.

[0090] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (851 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (436 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 1.24 g, 5.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 636 mg of yellow solid, yield 75%.

[0091] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 1.0 g, 1.0 equiv.), [2-(2-aminoethoxy)ethyl]carbamate tert-butyl ester (971 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 1.54 g, 5.0 equiv.), and n-butanol (nBuOH, 10 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 360 mg of a dark red viscous solid, with a yield of 26%.

[0092] Step 10: Dissolve the intermediate (83 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (99 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 150 mg, 3.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (97 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to obtain 37 mg of a yellow solid, yield 23%. This solid was C4-PEG1-PROTAC.

[0093] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 42 H 45 F5N 10 O9, 929.3364; Found: 929.3356.

[0094] Example 10 In this embodiment, a PROTAC compound targeting PI3Kα was prepared, abbreviated as C5-PEG1-PROTAC, with the following structural formula: .

[0095] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (500 mg, 1.0 equiv.), N-Boc-1,5-pentanediamine (403 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 468 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 336 mg of a yellow solid, yield 40%.

[0096] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (336 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and glutaric anhydride (118 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 364 mg, 3.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 188 mg of yellow solid, yield 41%.

[0097] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 1.0 g, 1.0 equiv.), [2-(2-aminoethoxy)ethyl]carbamate tert-butyl ester (971 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 1.54 g, 5.0 equiv.), and n-butanol (nBuOH, 10 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 360 mg of a dark red viscous solid, with a yield of 26%.

[0098] Step 10: Dissolve the intermediate (83 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (100 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 468 mg, 2.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (97 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (developing solvent: dichloromethane: methanol, volume ratio 12:1) to give 36 mg of a yellow solid, yield 22%. This solid was C5-PEG1-PROTAC.

[0099] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 43 H 47 F5N 10 O9, 943.3520; Found: 943.3521.

[0100] Example 11 In this embodiment, a PROTAC compound targeting PI3Kα was prepared, abbreviated as C5-4C-PEG1-PROTAC, with the following structural formula: .

[0101] The preparation method is as follows: Step 7: 2-(2,6-dioxadiidine-3-yl)-4-fluoroisoindoline-1,3-dione (1.0 g, 1.0 equiv.), N-Boc-1,5-pentanediamine (806 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 936 mg, 2.0 equiv.), and N-methylpyrrolidone (NMP, 10 mL) were added to a round-bottom flask and heated to 90 °C for 8 hours. After the reaction was complete, the mixture was diluted with a large amount of water, extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 5:1~3:1) to give 640 mg of a yellow solid, yield 39%.

[0102] Step 8 (Linker Preparation): The intermediate obtained in Step 7 (340 mg, 1.0 equiv.) was dissolved in dichloromethane (DCM, 3 mL) in a round-bottom flask, and 1 mL of trifluoroacetic acid (TFA) was added. The reaction was carried out at 10°C for 1 hour. After the reaction was completed, the reaction system was concentrated to obtain the crude product. The crude product was placed in a round-bottom flask, and succinic anhydride (169 mg, 1.1 equiv.), diisopropylethylamine (DIPEA, 521 mg, 5.0 equiv.), and N,N-dimethylformamide (DMF, 5 mL) were added. The reaction was carried out at room temperature for 4 hours. After the reaction was completed, a large amount of water was added for dilution, and the pH was adjusted to about 3.0 with 1 M citric acid. The mixture was extracted with ethyl acetate, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to silica gel column chromatography (eluent: petroleum ether: ethyl acetate, volume ratio 1:1) to obtain 500 mg of yellow solid, yield 74%.

[0103] Step 9: Under nitrogen protection, the chloride intermediate prepared in Step 6 (i.e., PI3Kα allosteric inhibitor head intermediate, 1.0 g, 1.0 equiv.), [2-(2-aminoethoxy)ethyl]carbamate tert-butyl ester (971 mg, 2.0 equiv.), diisopropylethylamine (DIPEA, 1.54 g, 5.0 equiv.), and n-butanol (nBuOH, 10 mL) were added to a three-necked flask and refluxed at 120 °C for 8 hours. After the reaction was completed, the solvent was removed by dilution under reduced pressure, and the mixture was diluted with ethyl acetate. Silica gel column chromatography (eluent: petroleum ether: ethyl acetate volume ratio of 3:1 to 1:1) yielded 360 mg of a dark red viscous solid, with a yield of 26%.

[0104] Step 10: Dissolve the intermediate (83 mg, 1.0 equiv.) obtained in Step 9 in dichloromethane (DCM, 2 mL) in a round-bottom flask, add 0.5 mL of trifluoroacetic acid (TFA), and react at room temperature for 1 hour. After the reaction is complete, concentrate the reaction system to obtain the crude product. Place the crude product in a round-bottom flask, add the linker (100 mg, 1.2 equiv.) obtained in Step 8, diisopropylethylamine (DIPEA, 468 mg, 2.0 equiv.), O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethylurea hexafluorophosphate (97 mg, 1.5 equiv.), and N,N-dimethylformamide (DMF, 3 mL), and react at room temperature for 16 hours. After the reaction is complete, dilute with a large amount of water, extract with ethyl acetate, separate the organic phase, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain the crude product. The crude product was purified twice using a pre-prepared plate (eluent: dichloromethane:methanol, volume ratio 12:1) to give 40 mg of a yellow solid, yield 24%. This solid was C5-4C-PEG1-PROTAC.

[0105] The high-resolution mass spectrometry data of the above compounds are as follows: HRMS (ESI, m / z) [M+H] + Calcd. forC 42 H 45 F5N 10 O9, 929.3364; Found: 929.3358.

[0106] Test case The antitumor activity of the PROTAC compounds in Examples 1-8 was tested.

[0107] 1. Materials and Instruments: (1) Cell line: SKOV-3 H1047R mutant cell line.

[0108] (2) Reagents: DMEM medium, fetal bovine serum, dimethyl sulfoxide, trypsin, penicillin-streptomycin solution, PBS buffer, sodium dodecyl sulfate, CCK-8 kit (Novizan), 96-well cell plate.

[0109] (3) Positive control: STX-478.

[0110] (4) Experimental instruments: carbon dioxide incubator, clean bench, inverted biological microscope (Olympus IX71), electronic balance (Mettler Toledo AL204), centrifuge (Feige TDL80-23).

[0111] (5) Sample preparation: The test sample and the control were prepared into a 1 mg / mL original solution using DMSO and stored. During the experiment, the solution was prepared into the required concentration using culture medium.

[0112] 2. Experimental Methods: (1) Cell culture: Cells were seeded in a culture medium containing 10% fetal bovine serum and 1% penicillin-streptomycin solution and placed in a 37℃, 5% CO2 incubator. Cells were passaged every 2-3 days and cells in the logarithmic growth phase were taken during the experiment.

[0113] (2) Preparation of cell suspension: If the cells are in suspension, collect the cells in the logarithmic growth phase directly by centrifugation; if the cells are adherent, digest them with trypsin and then collect them by centrifugation. Resuspend the collected cells in serum-containing medium, count them using a hemocytometer, and then dilute to 5×10⁻⁶. 4 A single-cell suspension of cells per mL.

[0114] (3) Adding cell suspension: Collect cells and add 100 μL of cell suspension (about 5000 cells) to a 96-well plate. Fill the edge wells with PBS and set up blank wells (with culture medium but no cells) and control wells (with culture medium and cells but no test drug). Set up 3-5 replicates for each group. Incubate the 96-well plate overnight in a 37°C, 5% CO2 incubator.

[0115] (4) Add the test drug: Add 10 μL of compound solution (PROTAC or positive control) of different concentrations to each well to make the final drug concentrations 1 μM, 3 μM and 10 μM. Incubate at 37°C for 24 hours.

[0116] (5) Add CCK-8: Add 10 μL of CCK-8 solution to each well and incubate at 37°C for 4 hours.

[0117] (6) Detection and Result Analysis: The OD value of each well was detected at a wavelength of 450 nm using an ELISA reader. Cell viability was calculated by subtracting the OD value of the control well from the OD value of each test well. Cell viability % = (OD of drug-treated cells - OD of blank cells) / (OD of control cells - OD of blank cells) × 100%.

[0118] Test results are as follows Figure 2 As shown, Figure 2 The novel PROTAC compounds disclosed herein can inhibit tumor cells and exhibit antitumor activity. Specifically, the C3-C10 PROTAC compounds involved in Examples 1-8, particularly the C4 PROTAC, exhibit proliferation-inhibiting activity comparable to that of positive control drugs at a low concentration (3 μM).

[0119] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this disclosure can be achieved, and this is not limited herein.

[0120] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0121] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A PROTAC compound targeting PI3Kα, characterized in that, The PROTAC compound is selected from the compound represented by formula (I) or its pharmaceutically acceptable salt, hydrate, solvate or prodrug, wherein the compound represented by formula (I) has the following general structural formula: （Ⅰ）； Where W is selected from C or O; x = 2~4; y = 1~3; z = 3~10.

2. The PROTAC compound according to claim 1, characterized in that, Formula (Ⅰ) is selected from compounds with the following structural formulas: 、 、 、 、 、 、 、 、 、 、 。 3. A pharmaceutical composition, characterized in that, The pharmaceutical composition comprises the PROTAC compound of any one of claims 1 to 2, and at least one pharmaceutically acceptable carrier, excipient, or diluent.

4. A method for preparing the PROTAC compound targeting PI3Kα according to any one of claims 1 to 2, characterized in that, Includes the following steps: S1: Preparation of intermediates for PI3Kα allosteric inhibitory heads; S2: Starting from 2-(2,6-dioxopiperidin-3-yl)-4-fluoroisoindoline-1,3-dione, reacting with NH2-(CH2) z -NHBoc undergoes a nucleophilic substitution reaction, where z = 3~10, to give an N-Boc protected CRBN ligand-linker intermediate; after removing the Boc protecting group, it reacts with... An acylation reaction is carried out, where y = 1~3, to obtain a CRBN ligand-linking chain intermediate; S3: Combine the PI3Kα allosteric repressor head intermediate obtained in step S1 with NH2-(CH2)2-W-(CH2). x -NHBoc undergoes a nucleophilic substitution reaction, wherein W is selected from C or O, and x = 2~4, to obtain an amino-substituted urea intermediate; the amino-substituted urea intermediate is then subjected to an amidation reaction with the CRBN ligand-linking chain intermediate obtained in step S2 under the action of a condensing agent and a base to obtain the PROTAC compound targeting PI3Kα.

5. The preparation method according to claim 4, characterized in that, Step S1, the preparation of the PI3Kα allosteric inhibitory head intermediate, includes: using 1-(3,5-difluoro-2-hydroxyphenyl)ethyl-1-one as the starting material, and proceeding through alkylation, cyclization, imidization, trifluoromethylation, deprotection, and ureation reactions to obtain the PI3Kα allosteric inhibitory head intermediate.

6. The preparation method according to claim 4, characterized in that, The nucleophilic substitution reaction in step S2 is carried out in DIPEA and NMP at 85-95°C for 6-10 hours; the Boc protecting group removal reaction is carried out in TFA and DCM at 8-12°C for 1-1.5 hours; and the acylation reaction is carried out in DIPEA and DMF at room temperature for 3-5 hours.

7. The preparation method according to claim 4, characterized in that, The condensing agent in step S3 is selected from any one of HATU, EDCl, HOBt, DCC, and PyBOP, and the base is selected from any one of DIPEA, triethylamine, and N-methylmorpholine.

8. The preparation method according to claim 7, characterized in that, The nucleophilic substitution reaction in step S3 is carried out at 110-130°C for 7-9 hours in DIPEA and nBuOH; the amidation reaction is carried out at room temperature for 15-17 hours in the presence of HATU and DIPEA.

9. The use of the PROTAC compound according to any one of claims 1 to 2 in the preparation of a medicament for treating diseases related to PI3Kα abnormalities.

10. The application according to claim 9, characterized in that, The diseases mentioned include any one of breast cancer, colorectal cancer, endometrial cancer, and ovarian cancer.

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