CN115124590B

CN115124590B - PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins, and preparation method and application thereof

Info

Publication number: CN115124590B
Application number: CN202210794029.6A
Authority: CN
Inventors: 周芙玲; 周海兵; 辛丽兰; 许荣; 谭御心; 张楠
Original assignee: Zhongnan Hospital of Wuhan University
Current assignee: Zhongnan Hospital of Wuhan University
Priority date: 2022-07-05
Filing date: 2022-07-05
Publication date: 2024-10-22
Anticipated expiration: 2042-07-05
Also published as: CN115124590A

Abstract

The invention discloses PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins, a preparation method and application thereof, wherein PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins have a structural formula shown in the following formula I or formula II: linker is a linking group selected from the group consisting of-alkylene, -alkoxy, and-heterocyclyl; e3 ligand is an E3 ligase ligand. The PROTAC compounds of the targeted degradation FLT3-ITD mutein have anti-AML activity, have obvious inhibitory activity on human acute myelogenous leukemia cell MOLM-13 cell line, can be developed as novel anti-AML drugs, and have wide application prospects.

Description

PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins, and preparation method and application thereof

Technical Field

The invention relates to the technical field of medicines, in particular to PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins, a preparation method and application thereof.

Background

Acute myelogenous leukemia (Acute myeloid leukemia, AML) is one of the most fatal hematological malignancies worldwide. Among all subtypes of leukemia, AML accounts for the highest percentage of leukemia deaths, up to about 62%, and patients have poor prognosis, short survival, and overall survival of less than 30% for five years. The most common mutant form in newly diagnosed AML patients is FLT3-ITD mutation, which is closely related to poor prognosis, high mortality, and high recurrence rate in patients.

Currently, the main drugs aimed at FLT3-ITD mutation are small molecule inhibitors, which can be classified into the first generation and the second generation according to their specificity for FLT3 protein kinase. The first generation of inhibitors are non-selective and multi-target inhibitors such as midostaurin and the like. As single drug treatments, these drugs have poor therapeutic effects and many adverse reactions, and some drugs are being further studied as combination therapies. The second generation inhibitors were more selective and showed stronger inhibition and less off-target toxicity to FLT3-ITD mutations, with gelitinib gaining FDA approval as a single agent in 2018 for treatment of relapsed or refractory AML patients. However, despite the clinical efficacy of second generation inhibitors, there are several unexpected safety and drug resistance issues that are urgently overcome due to changes in microenvironment or secondary mutations.

Compared with the traditional small molecule inhibitor, PROTAC (proteolysis targeting chimeric) can degrade the target protein by hijacking the inherent ubiquitin-proteinase system in the body through the action mechanism of inhibiting the function of the target protein by combining with the active site of the target protein, thereby achieving the aim of treatment. PROTAC is a bifunctional molecule consisting of three parts, a small molecule ligand that recognizes the target protein, an E3 ubiquitin protein ligase recruitment element, and a connecting strand that connects the two. Because the affinity requirement on the targeting protein small molecule ligand is not high, and the catalytic property of the targeting protein small molecule ligand enables the targeting protein small molecule ligand to play a protein degradation function in a small amount, the technology can well overcome the serious drug resistance problem of the existing drug.

Therefore, there is a need to develop PROTAC class of compounds that target degradation of FLT3-ITD muteins and methods for their preparation.

Disclosure of Invention

The invention aims to provide PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins, a preparation method and application thereof, wherein PROTAC compounds for targeted degradation of FLT3-ITD mutant proteins have anti-AML activity, have obvious inhibition activity on human acute myelogenous leukemia cell MOLM-13 cell lines, can be developed as novel anti-AML drugs, and have wide application prospects.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

in a first aspect of the invention, there is provided a PROTAC class of compounds targeted to degrade FLT3-ITD muteins, said PROTAC class of compounds targeted to degrade FLT3-ITD muteins having the structural formula shown in formula I or formula II below:

In the formula I or the formula II,

Linker is a linking group selected from one or more of a linear or branched alkylene, alkoxy or heterocyclyl ,-(CH₂)_n-、-(CH₂)_nCO-、-NR₁(CH₂)_nCO-、-NR₂(CH₂)_n-、-(OCH₂CH₂O)_n-、-(CH₂CH₂O)_n-、-(OCH₂CH₂OCH₂)_n-、-(CH₂CH₂OCH₂)_n-、-(CH₂CH₂OCH₂CH₂)_n-、 alkenylene, alkynylene, cycloalkylene, heteroarylene group or any combination thereof, wherein n represents a natural number from 1 to 20, R ₁、R₂ are each independently selected from H or are C _1-10 alkyl;

e3 ligand is an E3 ligase ligand selected from one of the following ligands:

further, the PROTAC class of compounds that target degradation of FLT3-ITD muteins include one of the following compounds X1-X22, the compounds X1-X22 being shown in table 1.

Table 1: PROTAC class compound overview for targeted degradation of FLT3-ITD muteins

Compounds numbered X-3, X-4, X-5, X-6, X-7, X-8, X-21, X-22 in Table 1 are PROTAC-class compounds with excellent activity that target degradation of FLT3-ITD muteins.

In a second aspect of the invention, there is provided an anti-AML pharmaceutical composition comprising a compound of the PROTAC class of targeted degradation FLT3-ITD muteins or a pharmacologically or physiologically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

In a third aspect of the invention, there is provided a method for preparing a PROTAC-class compound that target degradation of FLT3-ITD muteins, the method comprising:

The PROTAC compounds of the targeted degradation FLT3-ITD mutant protein are divided into a series I compound, a series II compound, a series III compound and a series IV compound, wherein,

The compound of the series I PROTAC is a compound shown in the general formula (I), linker is n=1-20-alkylene, E3 ligand is the VHL ligand, methyl-carrying VHL ligand, pomalidomide, lenalidomide or 4-hydroxy thalidomide;

the compound of the series II PROTAC is a compound shown in a general formula (II), linker is n=1-20-alkylene, and E3 ligand is the ligand with methyl VHL;

The compound III PROTAC is a compound shown in a general formula (I), linker is n=1-20-alkoxy, and E3 ligand is the ligand with methyl VHL;

The series IV PROTAC compounds are compounds shown in the general formula (I), linker is-heterocyclic group, and E3 ligand is the ligand with methyl VHL;

The preparation of the compounds of series I PROTAC includes two aspects:

(1) The gelitinib derivative I is reacted with a VHL ligand derivative substituted by a terminal halogen atom or a VHL ligand derivative with methyl in DMF (N, N-dimethylformamide) under the conditions of potassium carbonate and potassium iodide to obtain a series I (1) PROTAC compound. The reaction is carried out at 90℃with a preferred reaction time of 12h.

Synthesis route of compound of series I (1) PROTAC

(2) The gelitinib derivative I and the alkyl chain CRBN ligand derivative with substituted tail end halogen atom react in DMF under the condition of sodium bicarbonate to obtain a series of compounds I (2) PROTAC. The reaction is carried out at 90℃with a preferred reaction time of 5h.

Synthesis route of compound of series I (2) PROTAC

The preparation of the compound of the series II PROTAC comprises the following steps: the VHL ligand derivative with the tail end of N-Boc (tert-butyloxycarbonyl) substituted and the connecting chain of alkyl chain firstly removes the Boc protecting group under an acidic condition, and then reacts with the Gilitinib derivative II under the conditions of HATU (O- (7-azabenzotriazole-1-yl) -N, N, N ', N' -tetramethyl urea hexafluorophosphate) and DIPEA (N, N-diisopropylethylamine) in DMF to obtain a series of II PROTAC compounds. The reaction is carried out at room temperature, preferably for 0.5h.

Synthesis route of series II PROTAC compounds

The preparation of the series III PROTAC compounds comprises the following steps: the tert-butyl ester is removed from the gelitinib derivative I with tert-butyl ester substituted at the tail end and alkoxy chain at the connecting chain under the acidic condition, and then the gelitinib derivative I reacts with VHL ligand with methyl in DMF under the conditions of HATU and DIPEA to obtain a series of III PROTAC compounds. The reaction is carried out at room temperature, preferably for 0.5h.

Synthetic route for series III PROTAC compounds

The preparation of the series IV PROTAC compound comprises the following steps: the tert-butyl ester is removed from the gelitinib derivative I with the tert-butyl ester substituted end and the heterocyclic chain connected with the tertiarybutyl ester under the acidic condition, and then the gelitinib derivative I reacts with VHL ligand with methyl in DMF under the conditions of HATU and DIPEA to obtain a series of IV PROTAC compounds. The reaction is carried out at room temperature, preferably for 0.5h.

Synthetic route for series IV PROTAC compounds

Wherein the linking chain is an-alkylene, -alkoxy chain or-heterocyclyl group of n=1-20; r is any one of H atom or CH 3; x is CO or CH; y is N or C.

Further, the ratio of the amounts of the substances of the gelitinib derivative I, the VHL ligand derivative (or the methyl-carrying VHL ligand derivative), the potassium carbonate and the potassium iodide in the series I is 1:1.2:4:1.4;

The ratio of the amounts of the substance of the gelitinib derivative I, the CRBN ligand derivative, the NaHCO ₃ in the series II is 1:1.2:2; the ratio of the amounts of the substances of the gelitinib derivative II, of the methyl-carrying VHL ligand derivative, of HATU and of DIPEA in the series II is 1:1.2:1.1:6.0;

the ratio of the amounts of substance of the gemini derivative I with alkoxy side chains, of the methyl VHL ligand, of HATU and of DIPEA in series III is 1:1.2:1.1:6.0;

The ratio of the amounts of the substances of the gelitinib derivative I with heterocyclyl side chain, of the methyl VHL ligand, of HATU and of DIPEA in series IV is 1:1.2:1.1:6.0.

In a third aspect of the invention, there is provided the use of PROTAC class of compounds targeted to degrade FLT3-ITD muteins or of the anti-AML pharmaceutical composition as FLT3-ITD degradants in anti-AML.

One or more technical solutions in the embodiments of the present invention at least have the following technical effects or advantages:

The PROTAC compounds of the targeted degradation FLT3-ITD mutant protein can effectively inhibit the activity of MOLM-13 cells, have better FLT3-ITD protein degradation capability, have better activity on AML mutant cells, and can be used for preparing anti-AML drugs.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 shows the results of the proteolytic activity of a portion of the compounds synthesized according to the invention.

Detailed Description

The advantages and various effects of the present invention will be more clearly apparent from the following detailed description and examples. It will be understood by those skilled in the art that these specific embodiments and examples are intended to illustrate the invention, not to limit the invention.

Throughout the specification, unless specifically indicated otherwise, the terms used herein should be understood as meaning as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification will control.

Unless specifically indicated otherwise, the various raw materials, reagents, instruments, equipment, etc., used in the present invention are commercially available or may be obtained by existing methods.

The PROTAC compounds for targeted degradation of FLT3-ITD muteins, the preparation method and the application thereof in resisting acute myeloid leukemia are described in detail below with reference to examples, comparative examples and experimental data.

Example 1, 6-Ethyl-3- (3-methoxy-4- (piperazin-1-yl) phenyl) amino) -5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide

This preparation provides two synthetic routes in the present invention, one as shown below.

Step 1: preparation of 4- (2-methoxy-4-nitrophenyl) piperazine-1-carboxylic acid tert-butyl ester

Compound 2-fluoro-5-nitroanisole 1 (1.0 g,1.0 eq) and compound 1-t-butoxycarbonyl piperazine 2 (1.2 g,1.1 eq) were weighed into a 100mL round bottom flask, dissolved by adding DMF (10 mL), followed by adding anhydrous K ₂CO₃ (2.4 g,3.0 eq) and stirring at 95 ℃ for 4h. After TLC monitoring reaction is completed, the reaction solution is cooled to room temperature, a proper amount of water is added, solid is separated out, suction filtration is carried out, a filter cake is rinsed twice by PE, and the yellow solid product 3,1.8g is obtained after drying at 65 ℃, and the reaction yield is 91.32％.¹H NMR(400MHz,Chloroform-d)δ7.88(dd,J＝8.8,2.5Hz,1H),7.74(d,J＝2.5Hz,1H),6.90(d,J＝8.8Hz,1H),3.98(s,3H),3.63(t,J＝5.0Hz,4H),3.18(t,J＝5.0Hz,4H),1.50(s,9H).

Step 2: preparation of 4- (4-amino-2-methoxyphenyl) piperazine-1-carboxylic acid tert-butyl ester

Compound 3 (1.0 g,1.0 eq) was weighed into a 100mL round bottom flask, dissolved by adding solvent EtOH (25 mL), followed by adding Fe powder (1.3 g,8.0 eq), NH ₄ Cl (1.6 g,10.0 eq) was weighed into an aqueous solution, heated to 90 ℃ and stirred at that temperature for 1h. After TLC monitoring the completion of the reaction, the reaction solution was filtered through celite, the cake was washed with EtOH (25 mL), the filtrate was collected and concentrated under reduced pressure, the concentrated product was dissolved with EA (50 mL), washed twice with water (2X 50 mL), anhydrous Na ₂SO₄ was used to dry the organic phase, and the EA was distilled off under reduced pressure, giving a pale brown solid product 4, 600.0mg, which was purified by column chromatography in the following reaction yield 65.85％.¹H NMR(400MHz,Chloroform-d)δ6.76(d,J＝8.2Hz,1H),6.29(d,J＝2.5Hz,1H),6.26(dd,J＝8.2,2.5Hz,1H),3.83(s,3H),3.60(t,J＝5.0Hz,4H),3.56(s,2H),2.91(t,J＝5.0Hz,4H),1.50(s,9H).

Step 3: preparation of tert-butyl 4- (3-carbamoyl-6-chloro-5-ethylpyrazin-2-yl) amino) -2-methoxyphenyl) piperazine-1-carboxylate

Compound 4 (200.0 mg,1.0 eq) and compound 3, 5-dichloro-6-ethylpyrazine-2-carboxamide 5 (171.8 mg,1.2 eq) were weighed into a 40mL volume tube lock, dissolved in NMP (2 mL) and subsequently DIPEA (252.3 mg,2.0 eq) was added and stirred for 2h at 170 ℃. TLC monitoring of the reaction completion, extraction of the reaction solution with EA (3X 30 mL) and water (40 mL), combining the organic layers and washing with saturated brine (2X 40 mL), drying over anhydrous Na ₂SO₄, distillation under reduced pressure to remove EA, column chromatography purification gave product 6, 304.0mg as a yellow solid, reaction yield 95.16％.¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),7.77(d,J＝4.3Hz,1H),7.41(d,J＝2.4Hz,1H),7.18(dd,J＝8.6,2.4Hz,1H),6.91(d,J＝8.5Hz,1H),5.65(d,J＝4.0Hz,1H),3.93(s,3H),3.64(t,J＝4.9Hz,4H),3.00(t,J＝5.0Hz,4H),2.88(q,J＝7.5Hz,2H),1.51(s,9H),1.33–1.30(m,3H).

Step 4: preparation of tert-butyl 4- (4- (3-carbamoyl-5-ethyl-6- (tetrahydro-2H-pyran-4-yl) amino) pyrazin-2-yl) amino) -2-methoxyphenyl) piperazine-1-carboxylate

Compound 6 (230 mg,1.0 eq) and compound 4-aminotetrahydropyran 7 (189.5 mg,4.0 eq) were weighed into a 40mL volume lock tube, NMP (1.5 mL) was added to dissolve, followed by DIPEA (242.3 mg,4.0 eq) and the lock tube was placed in a microwave reactor and stirred for 2h at 120 ℃. TLC monitoring of the reaction completion, extraction of the reaction solution with EA (3X 30 mL) and water (40 mL), combining the organic layers and washing with saturated brine (2X 40 mL), drying over anhydrous Na ₂SO₄, distillation under reduced pressure to remove EA, column chromatography purification gave product 8, 247.1mg as a yellow solid, reaction yield 94.93％.¹H NMR(400MHz,Chloroform-d)δ10.78(s,1H),7.55(d,J＝2.4Hz,1H),7.52(d,J＝2.3Hz,1H),6.92(d,J＝2.3Hz,1H),6.85(d,J＝8.7Hz,1H),5.28(d,J＝4.6Hz,1H),4.67(d,J＝7.3Hz,1H),4.27–4.18(m,1H),4.08–4.02(m,2H),3.90(s,3H),3.64(t,J＝5.0Hz,4H),3.59–3.51(m,2H),3.04–2.96(m,4H),2.54(q,J＝7.4Hz,2H),2.14–2.06(m,2H),1.64–1.54(m,2H),1.51(s,9H),1.32(t,J＝7.4Hz,3H).

Step 5: preparation of 6-ethyl-3- (3-methoxy-4- (piperazin-1-yl) phenyl) amino) -5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide

Compound 8 (385.1 mg,1.0 eq) was weighed into a 50mL round bottom flask, dissolved with DCM (4 mL), added excess TFA (4 mL) and stirred at room temperature for 1h. After TLC monitoring the reaction completion, DCM was distilled off under reduced pressure, the pH was adjusted to weakly basic with saturated NaHCO ₃ solution, the reaction solution was extracted with EA (3X 30 mL), the organic layers were combined, dried over anhydrous Na ₂SO₄, the solvent was distilled off under reduced pressure, and the column chromatography was purified to give a yellow solid product 9, 262.5mg, reaction yield was 83.14％.¹H NMR(400MHz,Chloroform-d)δ10.75(s,1H),7.54(d,J＝4.4Hz,1H),7.50(dd,J＝8.6,2.4Hz,1H),6.92(d,J＝2.3Hz,1H),6.87(d,J＝8.7Hz,1H),5.38(d,J＝4.5Hz,1H),4.67(d,J＝7.3Hz,1H),4.27–4.17(m,1H),4.07–4.00(m,2H),3.89(s,3H),3.59–3.50(m,2H),3.12–3.06(m,4H),3.06–2.98(m,4H),2.53(q,J＝7.4Hz,2H),2.14–2.06(m,2H),1.64–1.52(m,2H),1.31(t,J＝7.4Hz,3H).

The second synthesis route is shown below.

Step 1: preparation of 3, 5-dichloro-6-ethylpyrazine-2-carboxylic acid methyl ester

The compound 3, 5-dichloro-6-ethylpyrazine-2-carboxamide (600 mg,1.0 eq) was weighed into a 50mL round bottom flask, dissolved in 2mol/L methanol hydrochloride solution (14 mL, excess) and placed in an oil bath at 70℃for reflux reaction for 24h. After completion of the TLC detection, the solvent was distilled off under reduced pressure, dissolved in saturated NaHCO ₃ solution (40 mL), extracted with DCM (3X 30 mL), the organic layers were combined and washed with saturated brine (2X 40 mL), dried over anhydrous Na ₂SO₄, and distilled off under reduced pressure to give crude product, which was purified by column chromatography to give 446mg of colorless clear oily liquid 10 in 69.59% yield. ¹ H NMR (400 mhz, chloro-d) δ4.01 (s, 3H), 3.00 (q, j=7.5 hz, 2H), 1.32 (t, j=7.5 hz, 3H).

Step 2: preparation of methyl 3-chloro-6-ethyl-5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxylate

Compound 10 (4476 mg,1.0 eq) was weighed into a 50mL single-necked flask, 4-aminotetrahydropyran (383.8 mg,2.0 eq) was added, followed by DMF (3 mL) and triethylamine (576.0 mg,3.0 eq) in sequence, and stirred at room temperature for 2h. TLC monitoring of the reaction completion, dilution of the solution with water (30 mL), extraction of the reaction solution with EA (3X 30 mL), combining the organic layers and washing with saturated brine (2X 40 mL) to remove DMF, drying over anhydrous Na ₂SO₄, removal of the solvent by distillation under reduced pressure gave crude product, purification by column chromatography gave 469mg of pure white solid 11 in yield 82.40％.¹H NMR(400MHz,Chloroform-d)δ5.02(d,J＝7.5Hz,1H),4.28–4.17(m,1H),4.02–3.95(m,2H),3.92(s,3H),3.59–3.50(m,2H),2.65(q,J＝7.5Hz,2H),2.07–2.00(m,2H),1.64–1.49(m,2H),1.27(t,J＝7.5Hz,3H).

Step 3: preparation of methyl 3- (4- (tert-butoxycarbonyl) piperazin-1-yl) -3-methoxyphenyl) amino) -6-ethyl-5- ((tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxylate

A40 mL tube was sealed, and Compound 11 (214.5 mg,1.1 eq), compound 4 (200.0 mg,1.0 eq), 4, 5-bis (diphenylphosphine) -9, 9-dimethylxanthene (Xant-phos, 113.0mg,0.3 eq), cesium carbonate (636.0 mg,3.0 eq) and palladium acetate (43.8 mg,0.3 eq) were weighed in this order, and solvent THF (1.5 mL) was added under argon. The reaction system was reacted in a microwave reactor at 100℃for 1h. After the reaction, the reaction mixture was returned to room temperature, water was added in an amount of about 40mL, the reaction mixture was extracted with EA (3X 30 mL), the organic layers were combined and washed with saturated brine (40 mL) and saturated NaHCO ₃ solution, dried over anhydrous Na ₂SO₄, and the solvent was removed by distillation under reduced pressure to give crude product, and the crude product was purified by column chromatography to give 306mg of yellow solid 12 in the yield of 82.41％.¹H NMR(400MHz,Chloroform-d)δ10.78(s,1H),7.53(t,J＝3.7Hz,1H),7.50(d,J＝2.4Hz,1H),6.92(d,J＝2.3Hz,1H),6.84(d,J＝8.6Hz,1H),5.41(d,J＝4.6Hz,1H),4.72(d,J＝7.3Hz,1H),4.24–4.15(m,1H),4.07–4.00(m,2H),3.89(s,3H),3.63(t,J＝5.0Hz,4H),3.56–3.47(m,2H),2.98(dd,J＝8.2,3.5Hz,4H),2.53(q,J＝7.4Hz,2H),2.11–2.04(m,2H),1.63–1.55(m,2H),1.50(s,9H),1.30(t,J＝7.4Hz,3H).

Step 4: preparation of 3- (4- (tert-Butoxycarbonyl) piperazin-1-yl) -3-methoxyphenyl) amino) -6-ethyl-5- ((tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxylic acid

Compound 12 (306 mg,1.0 eq) was weighed into a 50mL single-necked flask, dissolved in methanol (8 mL), and reacted at 80℃for 18 hours with LiOH H ₂ O (101.2 mg,4.0 eq). TLC monitored completion of the reaction, extraction with EA (3×30 mL) and saturated NH ₄ Cl (50 mL) solution, combined organic layers and washed with saturated brine (2×40 mL), dried over anhydrous Na ₂SO₄, and distilled under reduced pressure to afford crude brown solid 13 (315.5 mg) which was used directly in the next reaction without further purification.

Step 5: preparation of tert-butyl 4- (4- (3-carbamoyl-5-ethyl-6- (tetrahydro-2H-pyran-4-yl) amino) pyrazin-2-yl) amino) -2-methoxyphenyl) piperazine-1-carboxylate

Compound 13 (315.5 mg,1.0 eq) was weighed into a 50ml single-necked flask, dissolved in DMF (5 ml) as a solvent, followed by dropping DIPEA (293.0 mg,4.0 eq) into the flask, stirring for several minutes, NH ₄ Cl (45.5 mg,1.5 eq) and HATU (237.1 mg,1.1 eq) were added in sequence, and the reaction solution was stirred at room temperature overnight. TLC showed that the reaction was complete, the reaction solution was extracted with EA (3X 30 mL) and water (40 mL), the organic layers were combined and washed with saturated brine (2X 40 mL), dried over anhydrous Na ₂SO₄, and distilled under reduced pressure to remove EA, and purified by column chromatography to give 300.0mg of yellow solid 8 in the yield of 95.40％.¹H NMR(400MHz,Chloroform-d)δ10.78(s,1H),7.53(t,J＝3.7Hz,1H),7.50(d,J＝2.4Hz,1H),6.92(d,J＝2.3Hz,1H),6.84(d,J＝8.6Hz,1H),5.41(d,J＝4.6Hz,1H),4.72(d,J＝7.3Hz,1H),4.26–4.16(m,1H),4.07–4.00(m,2H),3.89(s,3H),3.63(t,J＝5.0Hz,4H),3.58–3.49(m,2H),2.98(dd,J＝8.2,3.5Hz,4H),2.53(q,J＝7.4Hz,2H),2.12–2.06(m,2H),1.63–1.55(m,2H),1.50(s,9H),1.30(t,J＝7.4Hz,3H).

Step 6: preparation of 6-ethyl-3- (3-methoxy-4- (piperazin-1-yl) phenyl) amino) -5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide

Compound 8 (300.0 mg,1.0 eq) was weighed into a 50ml single-necked flask, dissolved in DCM (1.5 ml), TFA (1.5 ml, excess) was added dropwise and stirred at room temperature for 30min. TLC monitored completion of the reaction and distilled under reduced pressure to remove solvent and TFA. Column chromatography separation and purification gave 9, 230.0mg of yellow solid with yield 93.52％.¹H NMR(400MHz,Chloroform-d)δ10.76(s,1H),7.57–7.52(m,1H),7.49(dd,J＝8.6,2.3Hz,1H),6.92(d,J＝2.3Hz,1H),6.86(d,J＝8.7Hz,1H),5.47(s,1H),4.69(d,J＝7.3Hz,1H),4.27–4.17(m,1H),4.06–4.01(m,2H),3.88(s,3H),3.58–3.50(m,2H),3.15–3.11(m,4H),3.09–3.02(m,4H),2.53(q,J＝7.4Hz,2H),2.13–2.06(m,2H),1.64–1.52(m,2H),1.32(t,J＝7.4Hz,3H).

The synthesis method of the gelitinib derivative II is the same as that of the compound 13 in the first synthesis route.

Example 2, (2S, 4R) -1- (S) -2-amino-3, 3-dimethylbutyryl) -4-hydroxy-N- (S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) pyrrolidine-2-carboxamide

Step 1: preparation of tert-butyl (S) - (1- (4-bromophenyl) ethyl) carbamate

(S) - (-) -1- (4-bromophenyl) ethylamine 14 (5 g,1.0 eq) was weighed into a 100mL single-necked flask, dissolved in DCM (15 mL), followed by Et ₃ N (2.8 g,1.1 eq) and a solution of tert-butyl dicarbonate (6.0 g,1.1 eq) in DCM (5 mL) was slowly added with stirring after ice bath for several minutes. After the addition, the ice bath was removed and the reaction was carried out at room temperature for 2 hours. After completion of the TLC monitoring the reaction, the extraction with water and DCM (3X 30 mL) was performed, the organic layers were combined and backwashed twice with water (2X 40 mL), dried over anhydrous Na ₂SO₄, and the DCM was distilled off under reduced pressure to give the crude white solid product 15,7.57g in 100% yield.

Step 2: preparation of tert-butyl (S) - (1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamate

Separately, compound 15 (6 g,1.0 eq), 4-methylthiazole (4.0 g,2.0 eq), palladium acetate (44.8 mg,0.01 eq) and potassium acetate (3.9 g,2.0 eq) were weighed into a 150mL single-port bottle, argon was replaced, and DMAC (15 mL) was added under inert gas to dissolve, and heated to 90℃to react for 18 hours. After the reaction, the mixture was stirred for 1 hour with celite spread in a funnel, and the residue was washed with DMAC (20 mL), and the filtrate was taken, water was added to the filtrate in an amount of 4 to 5 times the volume of the filtrate under ice bath conditions, and an off-white solid was precipitated. Filtering to obtain filter residue, washing with PE, oven drying, and purifying by column chromatography to obtain pure white 17,3.3g product with yield of 52％.¹H NMR(400MHz,Chloroform-d)δ8.68(s,1H),7.42(d,J＝8.4Hz,2H),7.37(d,J＝8.1Hz,2H),4.94(s,1H),2.54(s,3H),1.48(d,J＝6.8Hz,3H),1.44(s,9H).

Step 3: preparation of tert-butyl (2S, 4R) -4-hydroxy-2- (S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamoyl) pyrrolidine-1-carboxylic acid

Compound 17 (6.0 g,1.0 eq) was weighed into a 50mL single-necked flask, dissolved in DCM (6 mL) and TFA (12 mL) was added dropwise and stirred at room temperature for 30min. After completion of the TLC monitoring, the solvent and TFA were distilled off under reduced pressure to give 18 as a brown oil, which was used directly in the next reaction. Deprotection intermediate 18 was dissolved in DMF (10 mL) followed by dropwise addition of DIPEA (9.7 g,4.0 eq), followed by stirring at room temperature for several minutes by the addition of Boc-L-hydroxyproline (4.8 g,1.1 eq) and HATU (7.9 g,1.1 eq) in sequence and reaction at room temperature for 30min. After the completion of the TLC monitoring, the reaction solution was extracted with EA (3X 40 mL) and water, and the organic phases were combined, washed with saturated brine (2X 40 mL), dried over anhydrous Na ₂SO₄, distilled off under reduced pressure, and purified by column chromatography to give a white solid product 19,5.8g. The total yield of the two steps was 71%.

Step 4: preparation of tert-butyl ((S) -1- ((2S, 4R) -4-hydroxy-2- ((S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamoyl) pyrrolidin-1-yl) -3, 3-dimethyl-1-oxobutan-2-yl) carbamate

Compound 19 (5.8 g,1.0 eq) was weighed into a 50mL single port flask and dissolved in DCM (10 mL) followed by dropwise TFA (10 mL) and stirred at room temperature for 30min. After completion of the TLC monitoring, the solvent and TFA were distilled off under reduced pressure to give 20 as a brown oily liquid, which was used directly in the next reaction. Deprotection intermediate 20 was dissolved in DMF (6 mL) followed by dropwise addition of DIPEA (10.4 g,6.0 eq), followed by stirring at room temperature for several minutes by the sequential addition of Boc-L-tert-leucine (4.7 g,1.5 eq) and HATU (5.6 g,1.1 eq) and reaction at room temperature for 30min. After the completion of the TLC monitoring, the reaction solution was extracted with EA (3X 40 mL) and water, and the organic phases were combined, washed with saturated brine (2X 40 mL), dried over anhydrous Na ₂SO₄, distilled off under reduced pressure, and purified by column chromatography to give 21.6 g of a white solid product. The total yield from the two steps was 36%.

Step 5: preparation of (2S, 4R) -1- (S) -2-amino-3, 3-dimethylbutyryl) -4-hydroxy-N- (S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) pyrrolidine-2-carboxamide

Compound 21 (3.0 g,1.0 eq) was weighed into a 50mL single port flask and dissolved in DCM (6 mL) followed by dropwise TFA (6 mL) and stirred at room temperature for 30min. After TLC monitored completion of the reaction, the solvent and most of TFA were distilled off under reduced pressure, pH was adjusted to 9-10 with saturated NaHCO ₃ solution, DCM was prepared, meoh=10:1 solvent extraction (3×30 mL) and the organic phases were combined, dried over anhydrous Na ₂SO₄, distilled off under reduced pressure, and purified by further column chromatography to give 22,2.0g as white solid product in yield 82％.¹H NMR(400MHz,Chloroform-d)δ8.66(s,1H),8.22(d,J＝7.3Hz,1H),7.37(s,4H),5.07(p,J＝7.0Hz,1H),4.78(t,J＝8.3Hz,1H),4.41(d,J＝3.7Hz,1H),3.79(d,J＝11.3Hz,1H),3.62–3.55(m,1H),3.38(s,1H),2.51(s,3H),2.22–2.12(m,2H),1.50(d,J＝6.9Hz,3H),0.99(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.26,170.77,150.40,148.28,143.97,131.66,130.52,129.46,126.27,69.84,60.33,58.77,56.87,48.87,37.13,35.67,26.13,22.42,16.08.

The preparation of VHL ligands without methyl groups is the same as above.

EXAMPLE 3 preparation of halogen-terminated alkyl chain VHL ligand

Taking the preparation of (2S, 4R) -1- (S) -2- (5-bromopentanylamino) -3, 3-dimethylbutyryl) -4-hydroxy-N- (S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) pyrrolidine-2-carboxamide (24) as an example, it is obtained by the following reaction.

Compound 22 (150.0 mg,1.0 eq) was weighed out with acid 23 (73.3 mg,1.2 eq) of the corresponding chain length in a 50mL single-necked flask, dissolved in DMF as solvent, followed by dropwise addition of DIPEA (261.6 mg,6.0 eq), stirred for several minutes, then added with condensing agent HATU (141.4 mg,1.1 eq) and reacted at room temperature for 30min. After TLC monitoring the completion of the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give the corresponding white solid product 24, 105mg in reaction yield 62％.¹H NMR(400MHz,Chloroform-d)δ8.70(s,1H),7.51(d,J＝7.9Hz,1H),7.41(d,J＝8.4Hz,2H),7.38(d,J＝8.5Hz,2H),6.39(d,J＝8.9Hz,1H),5.10(p,J＝7.0Hz,1H),4.68(t,J＝7.9Hz,1H),4.59(d,J＝8.9Hz,1H),4.51(s,1H),4.03(d,J＝11.3Hz,1H),3.64(dd,J＝11.3,3.8Hz,1H),3.39(t,J＝6.4Hz,2H),2.53(s,3H),2.44–2.36(m,1H),2.25–2.17(m,2H),2.12–2.03(m,1H),1.90–1.81(m,2H),1.79–1.70(m,2H),1.50–1.48(m,3H),1.05(s,9H).

Other alkyl chain VHL ligands terminated with halogen atoms are prepared as described above.

EXAMPLE 4 preparation of halogen-substituted-terminated alkyl chain CRBN ligand

By way of example, the preparation of 8-bromo-N- (2, 6-dioxopiperidin-3-yl) -1, 3-dioxoisooctan-4-yl) octanol (29) is obtained by the following reaction.

Compound 25 (1.5 g,1.0 eq) was weighed out, replaced with argon, dissolved in DCM (5 mL) as a solvent under the protection of inert gas, and compound 26, oxalyl chloride (1.7 g,2.0 eq), was slowly added dropwise under ice bath, followed by one drop of DMF, stirred under ice bath for several minutes and then reacted at room temperature for 2h. After completion of the reaction, DCM was removed by concentration under reduced pressure to give compound 27, which was used directly in the next step without purification. Solvent THF (5 ml) was added thereto for dissolution, and then compound 28 (0.92 g,0.5 eq) was added thereto for reaction at room temperature overnight. After the reaction, THF was distilled off under reduced pressure and purified by column chromatography to give 29 mg of a white solid product, 850mg, in two steps of total yield 26％.¹H NMR(400MHz,Chloroform-d)δ9.42(s,1H),8.83(d,J＝8.9Hz,2H),7.72(dd,J＝8.5,7.3Hz,1H),7.55(d,J＝7.3Hz,1H),5.03–4.94(m,1H),3.41(t,J＝6.8Hz,2H),2.94–2.85(m,1H),2.85–2.72(m,2H),2.47(t,J＝7.5Hz,2H),2.21–2.14(m,1H),1.90–1.82(m,2H),1.80–1.71(m,2H),1.47–1.33(m,6H).

By way of example, the preparation of 4- (8-bromooctyl) oxy) -2- (2, 6-dioxopiperidin-3-yl) isoindole-1, 3-dione (32) is obtained by the following reaction.

Compound 30 (300 mg,1.0 eq) and compound 31 (357.1 mg,1.2 eq) were weighed into a 50mL single-port bottle, dissolved by adding solvent DMF (5 mL), followed by dropwise addition of DIPEA (424.2 mg,3.0 eq) and heated to 90 ℃ for reaction for 3h. After completion of the TLC monitoring the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give compound 32, 165.0mg as a white solid in yield 32％.¹H NMR(400MHz,Chloroform-d)δ9.12(d,J＝5.7Hz,1H),7.60(t,J＝7.9Hz,1H),7.34(dd,J＝7.5,2.6Hz,1H),7.16(d,J＝8.5Hz,1H),4.50–4.92(m,1H),4.10(t,J＝6.6Hz,2H),3.36(t,J＝6.8Hz,2H),2.83–2.68(m,3H),2.12–2.01(m,1H),1.85–1.75(m,4H),1.50–1.41(m,2H),1.40–1.26(m,6H).

Other alkyl chain CRBN ligands with halogen atom substituted at the end are prepared as described above.

Example 5 preparation of the Compounds of the series I (1) PROTAC

Taking the preparation of 6-ethyl-3- ((4- (4- (5- ((S) -1- ((2S, 4 r) -4-hydroxy-2- ((S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamoyl) pyrrolidin-1-yl) -3, 3-dimethyl-1-oxobutan-2-yl) amino) -5-oxopentyl) piperazin-1-yl) -3-methoxyphenyl) amino) -5- ((tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide (X-1) as an example, it is obtained by the following reaction.

The corresponding compound 24 (64 mg,1.2 eq), K ₂CO₃ (48.5 mg,4.0 eq) and KI (21.9 mg,1.4 eq) were weighed into a single vial, dissolved in solvent DMF, stirred for several minutes and then added with compound 9 (40 mg,1.0 eq) and heated to 90℃overnight. After TLC monitoring the completion of the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give the corresponding target end product as yellow solid X-1, 26.6mg, in reaction yield 31％.¹H NMR(400MHz,Chloroform-d)δ10.74(s,1H),8.67(s,1H),7.59(d,J＝7.9Hz,1H),7.54(d,J＝4.8Hz,1H),7.46(dd,J＝8.6,2.3Hz,1H),7.38(d,J＝1.4Hz,4H),6.91(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),6.60(d,J＝8.9Hz,1H),5.60(d,J＝4.6Hz,1H),5.10(t,J＝7.2Hz,1H),4.75–4.69(m,2H),4.64(d,J＝9.0Hz,1H),4.51(s,1H),4.23–4.15(m,1H),4.07(d,J＝11.3Hz,1H),4.05–3.97(m,2H),3.85(s,3H),3.66–3.62(m,1H),3.55–3.47(m,4H),3.16–3.02(m,4H),3.68–2.79(m,4H),2.53–2.50(m,5H),2.43–2.37(m,1H),2.30–2.23(m,2H),2.16–2.11(m,1H),2.07(dd,J＝11.4,3.2Hz,2H),1.65(d,J＝8.4Hz,2H),1.60–1.54(m,4H),1.49(d,J＝6.9Hz,3H),1.33–1.29(m,3H),1.06(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.50,171.95,170.37,170.00,152.37,151.92,151.03,150.39,148.39,143.28,136.00,135.90,131.62,130.78,130.72,129.53,126.45,117.94,112.62,112.51,105.03,69.81,66.89,58.74,57.97,57.55,55.66,53.25,50.54,48.81,36.00,35.34,33.12,31.93,29.70,29.37,26.56,25.82,24.55,23.47,22.70,16.09,14.16,10.51.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₁H₇₂N₁₁O₇S]⁺982.5331;found 982.5368.

The other series of compounds I (1) were prepared as described above.

Example 6 preparation of the Compounds of the series I (2) PROTAC

Taking the preparation of 3- (4- (8- (2, 6-dioxopiperidin-3-yl) -1, 3-dioxoisooctanol-4-yl) amino) -8-oxooctyl) piperazin-1-yl) -3-methoxyphenyl) amino) -6-ethyl-5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide (X-14) as an example, it is obtained by the following reaction.

Compound 29 (100.8 mg,1.2 eq), compound 9 (80 mg,1.0 eq) were weighed into a 50mL single-port bottle, dissolved in DMF (3 mL) as solvent, then NaHCO ₃ solid (29.5 mg,2.0 eq) was added and heated to 90 ℃ for reaction for 3h. After TLC monitoring the completion of the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give the final product as a yellow solid X-14, 62.4mg in yield 42％.¹H NMR(400MHz,Chloroform-d)δ10.71(d,J＝5.4Hz,1H),9.45(s,1H),8.78(d,J＝8.5Hz,1H),7.72–7.63(m,1H),7.50(dd,J＝9.6,5.6Hz,2H),7.44(dd,J＝8.6,2.3Hz,1H),6.89(d,J＝2.3Hz,1H),6.84(d,J＝8.7Hz,1H),5.66(d,J＝4.6Hz,1H),4.97–4.91(m,1H),4.75(d,J＝7.3Hz,1H),4.21–4.13(m,1H),4.03–3.96(m,2H),3.83(s,3H),3.54–3.46(m,2H),3.13–3.02(m,4H),2.85–2.82(m,1H),2.80–2.58(m,6H),2.52–2.44(m,2H),2.43–2.37(m,2H),2.18–2.12(m,1H),2.08–2.02(m,2H),1.78–1.68(m,2H),1.60–1.50(m,4H),1.45–1.28(m,8H),1.28–1.26(m,3H).¹³C NMR(100MHz,Chloroform-d)δ172.46,171.88,170.45,169.28,168.89,166.80,152.36,151.92,151.01,137.71,136.35,136.26,135.73,131.13,130.70,125.17,118.37,117.82,115.34,112.47,104.99,66.88,58.72,55.61,53.32,50.67,49.34,47.67,45.86,37.80,33.06,31.47,29.67,29.21,28.89,27.59,26.51,25.29,24.50,22.78,14.83,14.15,10.49,9.62.HRMS-ESI(m/z):[M+H]⁺calcd for[C₄₄H₅₇N₁₀O₈]⁺853.4355;found 853.4352.

The other series of compounds I (2) were prepared as described above.

EXAMPLE 7 preparation of VHL ligand with N-Boc substituted connecting chain as alkyl chain

Taking the preparation of tert-butyl (6- ((S) -1- ((2S, 4 r) -4-hydroxy-2- ((S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamoyl) pyrrolidin-1-yl) -3, 3-dimethyl-1-oxobutan-2-yl) amino) -6-oxohexyl) carbamate (34) as an example, it is obtained by the following reaction.

Compound 22 (100 mg,1.0 eq) and the corresponding compound 33 (57.2 mg,1.1 eq) were weighed out and dissolved in a single vial, solvent DMF was added followed by dropwise DIPEA (116.3 mg,4.0 eq), HATU (94.1 mg,1.1 eq) was added after stirring for several minutes, and the reaction was carried out at room temperature for 1h. After TLC monitoring the completion of the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give the corresponding intermediate as a white solid 34, 140mg in reaction yield 97％.¹H NMR(400MHz,Chloroform-d)δ8.64(s,1H),7.63(d,J＝7.7Hz,1H),7.33(d,J＝2.3Hz,4H),6.69(d,J＝8.3Hz,1H),5.08–5.01(m,1H),4.65(t,J＝8.0Hz,1H),4.59(d,J＝9.2Hz,1H),4.45(s,1H),3.96(d,J＝11.0Hz,1H),3.67–3.58(m,1H),3.01(d,J＝6.7Hz,2H),2.46(s,3H),2.33–2.20(m,1H),2.20–2.10(m,2H),2.06(dd,J＝16.9,8.6Hz,1H),1.59–1.49(m,2H),1.42(d,J＝7.0Hz,3H),1.38(s,9H),1.25–1.20(m,2H),0.99(s,9H).

The preparation of other VHL ligands with N-Boc substituted linker chains as alkyl chains is the same as above.

Preparation of the Compounds of example 8, series II PROTAC

Taking the preparation of 6-ethyl-N- (6- (S) -1- (2S, 4 r) -4-hydroxy-2- (S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamoyl) pyrrolidin-1-yl) -3, 3-dimethyl-1-oxobutan-2-yl) amino) -6-oxohexyl) -3- (3-methoxy-4- (4-methylpiperazin-1-yl) phenyl) amino) -5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide (42 a) as an example, it is obtained by the following reaction.

The corresponding compound 34 (70.0 mg,1.0 eq) was weighed out and dissolved in DCM, followed by dropwise addition of excess TFA and reaction at room temperature for 30min. TLC monitored completion of the reaction and DCM and TFA were distilled off under reduced pressure to give 35 as a brown oil which was used directly in the next step without further purification. An appropriate amount of solvent DMF was added first to dissolve, DIPEA (100 mg,8.0 eq) was added dropwise and stirred for several minutes, followed by the sequential addition of compound 36 (45.5 mg,1.1 eq) and HATU (40.5 mg,1.1 eq) to react for 30min at room temperature. After TLC monitoring the completion of the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give the corresponding target PROTAC molecule as a yellow solid X-9, 77.5mg in reaction yield 67％.¹H NMR(400MHz,Chloroform-d)δ10.89(s,1H),8.65(s,1H),7.79–7.71(m,1H),7.53(d,J＝8.7Hz,1H),7.52–7.46(m,1H),7.34(d,J＝7.3Hz,4H),6.86(t,J＝2.8Hz,1H),6.82(dd,J＝9.3,5.1Hz,1H),6.46–6.35(m,1H),5.05(q,J＝6.8Hz,1H),4.76–4.69(m,1H),4.67(d,J＝7.4Hz,1H),4.59(d,J＝8.8Hz,1H),4.48(s,1H),4.20–4.16(m,1H),4.03–3.93(m,3H),3.83(s,3H),3.62(dd,J＝11.0,3.8Hz,1H),3.55–3.46(m,2H),3.38–3.31(m,2H),3.18–3.00(m,4H),2.75–2.65(m,4H),2.53–2.46(m,5H),2.42–2.30(m,4H),2.20–2.13(m,2H),2.10–2.00(m,3H),1.67–1.50(m,6H),1.45(d,J＝6.7Hz,3H),1.28–1.21(m,5H),1.01(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.41,171.73,170.07,167.55,152.42,151.60,150.51,150.41,148.33,143.29,136.01,135.95,131.60,130.73,130.33,129.49,126.46,117.92,113.13,111.98,104.68,69.77,66.93,58.80,57.39,56.78,55.63,55.30,50.83,48.77,47.67,46.07,45.86,38.81,38.66,36.29,36.02,35.41,33.12,30.31,29.72,28.89,26.56,26.50,25.36,24.60,23.69,22.97,22.21,16.07,14.08,10.71,9.63.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₃H₇₆N₁₁O₇S]⁺1010.5644;found 1010.5658.

Other series II PROTAC compounds were prepared as described above.

EXAMPLE 9 preparation of Gelidine derivative I with tert-butyl substituted connecting Strand as alkoxy Strand

Taking the preparation of tert-butyl 2- (2- (4- (4- (3-carbamoyl-5-ethyl-6- (tetrahydro-2H-pyran-4-yl) amino) pyrazin-2-yl) amino) -2-methoxyphenyl) piperazin-1-yl) ethoxy) acetate (41) as an example, it is obtained by the following reaction.

Step 1: preparation of tert-butyl acetate 2- (2- (2-hydroxyethoxy) ethoxy)

The corresponding compound 37 (6.0 g,1.0 eq) was weighed into a double-necked flask, kept under inert gas atmosphere by argon displacement, then dissolved by adding solvent DMF, and NaH (2.7 g,1.2 eq) was slowly added in portions under ice bath and stirred at room temperature for 1h. Then, tert-butyl bromoacetate 38 (11.0 g,1.0 eq) was added under ice bath, and the ice bath was removed and reacted overnight at room temperature. After the completion of the reaction, the reaction was quenched slowly with water, then the reaction solution was extracted with EA and water, the organic phases were combined and dried over anhydrous Na ₂SO₄, and the EA was distilled off under reduced pressure, followed by purification by column chromatography to give 39,0.7g of a yellow oily liquid as a compound, the reaction yield was 6%. ¹ H NMR (400 MHz, chloroform-d) delta 3.99 (s, 2H), 3.72-3.67 (m, 6H), 3.61-3.57 (m, 2H), 1.44 (s, 9H).

Step 2: preparation of tert-butyl 2- (2- (p-tolyloxy) ethoxy) acetate

The corresponding compound 39 (400 mg,1.0 eq) was weighed into a single vial and dissolved in solvent DCM, followed by sequential addition of p-toluenesulfonyl chloride (380.8 mg,1.1 eq), et ₃ N (643.8 mg,3.5 eq) and DMAP (13.3 mg,0.06 eq) for 2h at room temperature. After TLC monitoring the reaction, the reaction solution was extracted with DCM and water, the organic layers were combined and dried over anhydrous Na ₂SO₄, and further purified by column chromatography to give colorless liquid 40, 328.8mg, reaction yield 48％.¹H NMR(400MHz,Chloroform-d)δ7.81–7.74(m,2H),7.33(d,J＝8.1Hz,2H),4.19–4.12(m,2H),3.97(s,2H),3.72–3.65(m,2H),3.66–3.62(m,2H),3.62–3.59(m,2H),2.43(s,3H),1.46(s,9H).

Step 3: preparation of tert-butyl 2- (2- (4- (4- (3-carbamoyl-5-ethyl-6- (tetrahydro-2H-pyran-4-yl) amino) pyrazin-2-yl) amino) -2-methoxyphenyl) piperazin-1-yl) ethoxy) acetate

The corresponding compound 40 (45.2 mg,1.1 eq), K ₂CO₃ (60.7 mg,4.0 eq), KI (23.4 mg,1.3 eq) were weighed into a single vial, dissolved in DMF and stirred for several minutes, followed by the addition of compound 9 (50 mg,1.0 eq) and heated to 85℃for reaction overnight. After completion of the TLC monitoring, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography gave a yellow solid 41, 49.4mg, reaction yield was 68％.¹H NMR(400MHz,Chloroform-d)δ10.74(s,1H),7.49(d,J＝4.5Hz,1H),7.45(dd,J＝8.6,2.3Hz,1H),6.86(d,J＝2.3Hz,1H),6.82(d,J＝8.6Hz,1H),5.58(s,1H),4.78(d,J＝7.3Hz,1H),4.20–4.13(m,1H),4.02–3.98(m,2H),3.97–3.94(m,2H),3.82(s,3H),3.76(t,J＝5.5Hz,2H),3.70–3.67(m,2H),3.67–3.64(m,2H),3.52–3.45(m,2H),3.19–3.11(m,4H),2.96–2.85(m,4H),2.83(t,J＝5.6Hz,2H),2.49(q,J＝7.3Hz,2H),2.07–2.01(m,2H),1.60–1.52(m,2H),1.43(s,9H),1.35(t,J＝7.4Hz,3H).

Other preparation methods of the gefitinib derivative I with tert-butyl ester substituted connecting chain as alkoxy chain are the same as the preparation method.

Preparation of example 10, series III PROTAC Compounds

Taking the preparation of 6-ethyl-3- (4- (2- ((S) -1- (2S, 4 r) -4-hydroxy-2- ((S) -1- (4- (4-methylthiazol-5-yl) phenyl) ethyl) carbamoyl) pyrrolidin-1-yl) -3, 3-dimethyl-1-oxobutan-2-yl) amino) -2-oxoethoxy) ethyl) piperazin-1-yl) -3-methoxyphenyl) amino) -5- (tetrahydro-2H-pyran-4-yl) amino) pyrazine-2-carboxamide (X-19) as an example, it is obtained by the following reaction.

The corresponding compound 41 (49.3 mg,1.0 eq) was weighed out and dissolved in solvent DCM followed by the addition of excess TFA and reaction at room temperature for 2h. After the completion of the reaction, distillation under reduced pressure gave brown oily liquid 42 which was used in the next step without further purification. Solvent DMF was added to dissolve compound 42, DIPEA (58.1 mg,6.0 eq) was added dropwise followed by stirring for several minutes, then compound 22 (40.0 mg,1.2 eq) was added sequentially with HATU (31.3 mg,1.1 eq) and reacted at room temperature for 30min. After completion of the TLC monitoring, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give X-19 as a yellow solid, 34mg, in the reaction yield of 44％.¹H NMR(400MHz,Chloroform-d)δ10.74(s,1H),8.67(s,1H),7.57(d,J＝7.7Hz,1H),7.53(d,J＝4.6Hz,1H),7.46(dd,J＝8.6,2.3Hz,1H),7.38(d,J＝2.6Hz,4H),7.35(s,1H),6.91(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),5.52(d,J＝4.5Hz,1H),5.12–5.04(m,1H),4.78–4.74(m,1H),4.70(d,J＝7.3Hz,1H),4.60(d,J＝8.8Hz,1H),4.24–4.14(m,1H),4.06–3.98(m,5H),3.85(s,3H),3.73–3.69(m,2H),3.68–3.62(m,6H),3.55–3.47(m,2H),3.13–3.04(m,4H),2.76–2.67(m,6H),2.55–2.49(m,5H),2.48–2.42(m,1H),2.10–2.03(m,3H),1.61–1.53(m,2H),1.48(d,J＝6.9Hz,3H),1.29(t,J＝7.4Hz,3H),1.08(s,9H).¹³C NMR(100MHz,CDCl₃)δ171.31,170.35,170.29,169.97,152.39,151.91,151.02,150.35,148.37,143.34,136.24,135.78,131.65,130.71,130.67,129.50,126.42,117.84,112.64,112.52,105.06,71.20,70.47,70.31,69.86,68.92,66.91,58.64,57.72,57.03,56.78,55.66,53.89,50.84,48.85,47.66,45.95,35.84,35.47,33.12,29.69,26.52,24.54,22.35,16.10,10.53.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₂H₇₄N₁₁O₉S]⁺1028.5386;found 1028.5391.

The preparation methods of other series III and series IV PROTAC compounds are the same as those described above.

EXAMPLE 11 preparation of Gelitinib derivative I with tert-butyl substituted connecting chain as heterocyclyl chain

Taking the preparation of tert-butyl 2- (4- (4- (3-carbamoyl-5-ethyl-6- (tetrahydro-2H-pyran-4-yl) amino) pyrazin-2-yl) amino) -2-methoxyphenyl) piperazin-1-yl) ethyl) piperazin-1-yl) acetate (44) as an example, it is obtained by the following reaction.

Compound 43 was prepared according to the procedure in reference example 9. Compound 43 (122.7 mg) was weighed into a single vial, dissolved in DCM, added with excess TFA and reacted at room temperature for 30min. After the reaction was completed, excess TFA and solvent were distilled off under reduced pressure, pH was adjusted to 9-10 by dissolution with NaHCO ₃, the reaction solution was extracted with DCM, the organic phases were combined and dried over anhydrous Na ₂SO₄, DCM was distilled off under reduced pressure to give the corresponding crude compound, which was further purified by column chromatography to give the debonded Boc intermediate 44, 52.4mg, the reaction yield was 50％.¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),7.51(d,J＝4.5Hz,1H),7.46(dd,J＝8.6,2.3Hz,1H),6.87(d,J＝2.3Hz,1H),6.83(d,J＝8.6Hz,1H),5.62(d,J＝4.6Hz,1H),4.67(d,J＝7.3Hz,1H),4.23–4.12(m,1H),4.03–3.96(m,2H),3.85(s,3H),3.54–3.45m,2H),3.16–2.99(m,4H),2.89(t,J＝4.9Hz,4H),2.75–2.65(m,4H),2.62–2.58(m,2H),2.57–2.53(m,2H),2.49(q,J＝7.0,6.4Hz,6H),2.08–2.02(m,2H),1.60–1.50(m,2H),1.27(t,J＝7.4Hz,3H)., compound 44 (52.4 mg,1.0 eq) and tert-butyl bromoacetate (18.0 mg,1.0 eq) were weighed into a single vial, solvent DMF was added to dissolve, K ₂CO₃ solid (51.0 mg,4.0 eq) was added, and heated to 50 ℃ for 2h. After TLC monitoring the completion of the reaction, the reaction solution was extracted with EA (3X 30 mL) and water, the organic phases were combined, and the organic phase was washed with saturated brine (2X 40 mL) to remove excess DMF, followed by drying over anhydrous Na ₂SO₄, removal of EA by distillation under reduced pressure, and further purification by column chromatography to give 45.16 mg of a yellow solid in the reaction yield of 26％.¹H NMR(400MHz,Chloroform-d)δ10.75(s,1H),7.54–7.47(m,2H),6.90(d,J＝2.3Hz,1H),6.86(d,J＝8.6Hz,1H),5.30(s,1H),4.65(d,J＝7.3Hz,1H),4.25–4.16(m,1H),4.06–4.00(m,2H),3.87(s,3H),3.57–3.49(m,2H),3.13–3.05(m,6H),2.82–2.73(m,4H),2.71–2.57(m,12H),2.56–2.49(m,2H),2.12–2.06(m,2H),1.62–1.53(m,2H),1.47(s,9H),1.31(t,J＝7.3Hz,3H).

EXAMPLE 12 preparation and characterization of PROTAC Compounds targeting degradation of FLT3-ITD muteins

(1) Compounds numbered X-2 in Table 1

The title compound was prepared according to the procedure in example 5 in 46% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),8.67(s,1H),7.56(d,J＝7.8Hz,1H),7.53(d,J＝4.6Hz,1H),7.45(dd,J＝8.6,2.3Hz,1H),7.40–7.33(m,4H),6.91(d,J＝2.3Hz,1H),6.84(d,J＝8.6Hz,1H),6.60(d,J＝9.0Hz,1H),5.70(d,J＝4.5Hz,1H),5.12–5.06(m,1H),4.76–4.70(m,2H),4.64(d,J＝9.0Hz,1H),4.51(s,1H),4.23–4.14(m,1H),4.08–3.96(m,5H),3.85(s,3H),3.63(dd,J＝11.2,3.6Hz,1H),3.55–3.46(m,2H),3.16–3.30(m,4H),2.78–2.62(m,4H),2.54–2.47(m,5H),2.45–2.37(m,3H),2.26–2.17(m,2H),2.11–2.03(m,3H),1.67–1.61(m,2H),1.50–1.46(m,4H),1.48(d,J＝6.9Hz,3H),1.32–1.29(m,3H),1.05(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.58,171.95,170.41,170.05,152.37,151.92,151.01,150.40,148.36,143.30,136.07,135.86,131.62,130.75,129.51,126.46,117.90,112.59,112.49,105.02,69.72,66.90,58.79,58.34,57.45,56.95,55.66,53.29,50.61,48.79,47.65,45.68,36.18,35.99,35.46,34.46,33.09,31.91,29.68,29.35,27.06,26.56,26.07,25.39,24.53,22.69,22.25,16.09,14.83,14.15,10.51,9.32.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₂H₇₄N₁₁O₇S]⁺986.5488;found 986.5491.

(2) Compounds numbered X-3 in Table 1

The title compound was prepared according to the procedure in example 5 in a yellow solid yield of 60%.

¹H NMR(400MHz,Chloroform-d)δ10.74(s,1H),8.67(s,1H),7.63(d,J＝7.9Hz,1H),7.53(d,J＝4.5Hz,1H),7.46(dd,J＝8.6,2.3Hz,1H),7.38(s,4H),6.90(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),6.51(d,J＝9.0Hz,1H),5.68(d,J＝4.5Hz,1H),5.12–5.07(m,1H),4.77–4.70(m,2H),4.64(d,J＝9.0Hz,1H),4.51(s,1H),4.23–4.14(m,1H),4.08–3.98(m,3H),3.85(s,3H),3.65–3.61(m,1H),3.57–3.47(m,4H),3.18–3.04(m,4H),2.79–3.69(m,4H),2.55–2.48(m,5H),2.41–2.35(m,1H),2.24–2.18(m,2H),2.06(dd,J＝13.1,4.2Hz,3H),1.61(d,J＝6.4Hz,2H),1.59–1.52(m,4H),1.49(d,J＝6.9Hz,3H),1.43(dd,J＝8.3,6.3Hz,2H),1.33–1.29(m,5H),1.05(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.64,171.76,170.40,170.17,152.36,151.93,151.00,150.38,148.34,143.43,135.98,135.86,131.66,130.80,130.69,129.49,126.47,118.01,112.60,112.45,104.98,69.80,66.89,58.84,58.35,57.40,56.94,55.66,53.20,52.83,50.35,48.79,47.66,36.31,36.19,35.46,34.46,33.09,31.91,31.50,30.12,29.68,29.36,28.87,27.02,26.54,25.96,25.48,24.54,22.28,16.08,14.82,14.15,7.92.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₃H₇₆N₁₁O₇S]⁺1010.5644;found 1010.5665.

(3) Compounds numbered X-4 in Table 1

¹H NMR(400MHz,Chloroform-d)δ10.74(s,1H),8.66(s,1H),7.57(d,J＝7.8Hz,1H),7.52(d,J＝4.6Hz,1H),7.44(dd,J＝8.6,2.3Hz,1H),7.37(s,4H),6.90(d,J＝2.3Hz,1H),6.84(d,J＝8.7Hz,1H),6.48(d,J＝9.0Hz,1H),5.79(d,J＝4.5Hz,1H),5.12–5.05(m,1H),4.78–4.69(m,2H),4.64(d,J＝9.0Hz,1H),4.51(s,1H),4.23–4.14(m,1H),4.05–3.96(m,3H),3.85(s,3H),3.63(dd,J＝11.1,3.9Hz,1H),3.53–3.46(m,2H),3.18–3.00(m,4H),2.79–2.64(m,4H),2.54–2.46(m,5H),2.45–2.38(m,3H),2.22–2.15(m,2H),2.09–2.02(m,3H),1.62–1.50(m,6H),1.47(d,J＝6.9Hz,3H),1.33–1.25(m,9H),1.04(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.56,171.87,170.43,170.14,152.37,151.92,151.00,150.40,148.35,143.33,136.07,135.87,131.62,130.76,129.49,126.47,117.91,112.59,112.50,105.01,69.71,66.90,58.82,58.64,57.33,56.89,55.65,53.35,50.61,48.78,47.66,45.83,36.38,35.51,33.08,31.90,29.68,29.34,29.01,28.90,27.20,26.54,26.23,25.50,24.53,22.68,16.08,14.83,14.16,10.51.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₄H₇₈N₁₁O₇S]⁺1024.5801;found 1024.5806.

(4) Compounds numbered X-5 in Table 1

The title compound was prepared according to the procedure in example 5 in 66% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.72(s,1H),8.67(s,1H),7.60(d,J＝7.9Hz,1H),7.52(d,J＝4.6Hz,1H),7.44(dd,J＝8.5,2.3Hz,1H),7.38(s,4H),6.90(d,J＝2.3Hz,1H),6.85(d,J＝8.7Hz,1H),6.48(d,J＝8.9Hz,1H),5.78–5.72(m,1H),5.14–5.05(m,1H),4.75(d,J＝7.3Hz,1H),4.70(t,J＝7.9Hz,1H),4.63(d,J＝9.0Hz,1H),4.49(d,J＝5.5Hz,1H),4.23–4.14(m,1H),4.07–3.98(m,3H),3.85(s,3H),3.63(dd,J＝11.2,3.7Hz,1H),3.55–3.46(m,2H),3.17–2.99(m,6H),2.74–2.58(s,4H),2.54–2.46(m 5H),2.43–2.35(m,3H),2.17(t,J＝7.6Hz,2H),2.10–2.03(m,3H),1.56(dd,J＝12.0,4.3Hz,4H),1.48(d,J＝6.9Hz,3H),1.30–1.27(m,5H),1.26–1.23(m,6H),1.04(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.73,171.84,170.42,170.09,152.38,151.93,151.03,150.42,148.37,143.31,136.18,135.81,131.62,129.51,126.49,117.91,112.60,112.54,105.05,69.81,66.91,58.81,58.74,57.38,56.84,55.66,53.50,53.38,50.70,48.79,47.66,36.45,35.99,35.45,33.10,31.92,31.51,30.12,29.69,29.29,29.13,29.09,27.42,26.54,25.64,24.53,22.69,22.23,16.09,14.83,14.15,10.52.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₅H₈₀N₁₁O₇S]⁺1038.5957;found 1038.5986.

(5) Compounds numbered X-6 in Table 1

The title compound was prepared according to the procedure for example 5 in 63% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),8.67(s,1H),7.58(d,J＝7.8Hz,1H),7.52(d,J＝4.5Hz,1H),7.44(dd,J＝8.6,2.3Hz,1H),7.37(s,4H),6.90(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),6.48(d,J＝8.9Hz,1H),5.84(d,J＝5.3Hz,1H),5.09(t,J＝7.2Hz,1H),4.77(d,J＝7.2Hz,1H),4.70(t,J＝7.8Hz,1H),4.62(d,J＝8.9Hz,1H),4.51(s,1H),4.23–4.14(m,1H),4.05–3.96(m,3H),3.85(s,3H),3.64(dd,J＝11.2,4.0Hz,1H),3.53–3.47(m,2H),3.16–2.96(m,4H),2.77–2.63(m,4H),2.53–2.46(m,5H),2.45–2.37(m,3H),2.17(t,J＝7.6Hz,2H),2.05(dd,J＝13.7,3.8Hz,3H),1.60–1.51(m,6H),1.47(d,J＝6.9Hz,3H),1.31–1.25(m,13H),1.04(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.65,171.84,170.45,170.14,152.38,151.93,151.01,150.43,148.34,143.33,136.14,135.84,131.62,130.78,130.75,126.49,117.92,112.58,105.03,69.79,66.91,58.87,58.75,57.37,56.83,55.65,53.38,50.67,48.77,47.66,38.84,36.07,35.50,33.07,29.67,29.41,29.33,29.20,28.95,27.49,25.70,24.52,23.95,22.96,22.23,16.09,14.08,10.52.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₆H₈₂N₁₁O₇S]⁺1052.6114;found 1052.6117.

(6) Compounds numbered X-7 in Table 1

The title compound was prepared as a yellow solid in 44% yield by the procedure of example 5.

¹H NMR(400MHz,Chloroform-d)δ10.71(s,1H),8.67(s,1H),7.56(d,J＝7.8Hz,1H),7.52(d,J＝4.7Hz,1H),7.45(dd,J＝8.6,2.3Hz,1H),7.38(d,J＝1.7Hz,4H),6.90(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),6.41(d,J＝9.1Hz,1H),5.65(d,J＝4.6Hz,1H),5.12–5.07(m,1H),4.75–4.68(m,2H),4.62(d,J＝9.0Hz,1H),4.52–4.49(m,1H),4.25–4.14(m,1H),4.07–3.97(m,3H),3.86(s,3H),3.63(dd,J＝11.2,3.7Hz,1H),3.55–3.47(m,2H),3.16–2.99(m,6H),2.73–2.65(m,4H),2.54–2.47(m,5H),2.42–2.37(m,3H),2.17(t,J＝7.6Hz,2H),2.10–2.04(m,3H),1.56(dd,J＝12.5,4.4Hz,4H),1.48(d,J＝6.9Hz,3H),1.31–1.25(m,15H),1.04(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.79,171.89,170.39,170.02,152.39,151.93,151.04,150.40,148.40,143.28,136.08,135.88,131.61,130.80,130.72,129.53,126.48,117.97,112.63,112.53,105.06,69.85,66.90,58.75,57.39,56.81,55.66,53.49,53.34,50.56,48.80,47.65,36.51,35.87,33.12,31.92,29.69,29.46,29.41,29.35,29.24,29.19,26.53,26.41,25.65,24.54,22.69,22.22.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₇H₈₃N₁₁O₇S]⁺1066.6270;found 1066.6302.

(7) Compounds numbered X-8 in Table 1

The title compound was prepared according to the procedure in example 5 in 52% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.72(s,1H),8.68(s,1H),7.59(d,J＝7.9Hz,1H),7.53(d,J＝4.5Hz,1H),7.45(dd,J＝8.5,2.3Hz,1H),7.39(s,4H),6.91(d,J＝2.3Hz,1H),6.86(d,J＝8.6Hz,1H),6.44(d,J＝8.9Hz,1H),5.71(d,J＝4.5Hz,1H),5.10(p,J＝7.0Hz,1H),4.74(d,J＝7.3Hz,1H),4.68(d,J＝8.0Hz,1H),4.62(d,J＝8.9Hz,1H),4.50(s,1H),4.24–4.15(m,1H),4.08–3.99(m,3H),3.86(s,3H),3.63(dd,J＝11.3,3.6Hz,1H),3.55–3.47(m,2H),3.16–3.00(m,4H),2.76–2.64(m,4H),2.54–2.47(m,5H),2.45–2.36(m,3H),2.17(t,J＝7.6Hz,2H),2.12–2.03(m,3H),1.62–1.52(m,6H),1.49(d,J＝6.9Hz,3H),1.31–1.23(m,17H),1.05(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.87,171.84,170.40,170.06,152.39,151.92,151.04,150.43,148.38,143.27,136.23,135.78,131.60,130.80,130.69,129.52,126.49,117.90,112.59,112.54,105.04,69.86,66.91,58.80,57.39,56.83,55.65,53.41,50.76,48.80,47.65,36.52,35.90,35.38,33.11,29.69,29.54,29.52,29.49,29.43,29.28,29.24,27.60,26.64,26.53,25.68,24.54,22.21,16.09,10.51.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₈H₈₅N₁₁O₇S]⁺1080.6427;found 1080.6427.

(8) Compounds numbered X-10 in Table 1

The title compound was prepared as a yellow solid in 44% yield by the procedure described in example 8.

¹H NMR(400MHz,Chloroform-d)δ10.94(s,1H),8.67(s,1H),7.77(t,J＝6.1Hz,1H),7.58–7.50(m,2H),7.41–7.35(m,4H),6.88(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),6.28(d,J＝8.8Hz,1H),5.08(q,J＝7.2Hz,1H),4.72–4.64(m,2H),4.59(d,J＝8.8Hz,1H),4.50(s,1H),4.25–4.15(m,1H),4.05–3.98(m,3H),3.85(s,3H),3.62(dd,J＝11.3,3.8Hz,1H),3.58–3.49(m,2H),3.38(q,J＝6.9Hz,2H),3.18–3.01(m,4H),2.75–2.63(m,4H),2.51(d,J＝4.3Hz,5H),2.43(t,J＝6.9Hz,1H),2.39(s,3H),2.16(t,J＝7.5Hz,2H),2.11–2.05(d,J＝15.3Hz,3H),1.64–1.53(m,6H),1.48(d,J＝6.9Hz,3H),1.30–1.24(m,9H),1.03(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.60,171.71,170.08,167.51,152.42,151.58,150.50,150.43,148.35,143.29,136.18,135.73,131.60,130.77,130.26,129.50,126.49,118.01,113.25,111.89,104.62,69.80,66.94,58.82,57.36,56.77,55.64,55.22,50.64,48.77,47.68,45.90,38.97,36.43,36.02,35.43,33.14,31.91,29.88,29.68,29.09,28.98,26.86,26.51,25.56,24.58,22.69,22.20,16.08,14.16,10.67.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₅H₈₀N₁₁O₇S]⁺1038.5957;found 1038.5945.

(9) Compounds numbered X-11 in Table 1

The title compound was prepared according to the procedure for example 8 in 42% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.99(s,1H),8.66(s,1H),7.76(t,J＝6.0Hz,1H),7.58(dd,J＝8.6,2.3Hz,1H),7.50(d,J＝7.8Hz,1H),7.37(d,J＝2.8Hz,4H),6.86–6.82(m,2H),6.26(d,J＝8.7Hz,1H),5.10–5.05(m,1H),4.73–4.66(m,2H),4.58(d,J＝8.8Hz,1H),4.51–4.48(m,1H),4.24–4.15(m,1H),4.03–3.98(m,3H),3.84(s,3H),3.62(dd,J＝11.1,3.9Hz,1H),3.57–3.49(m,2H),3.40–3.35(m,2H),3.23–3.16(m,4H),2.83–2.97(m,4H),2.55–2.51(m,5H),2.50(s,3H),2.46–2.37(m,1H),2.14(t,J＝7.6Hz,2H),2.10–2.04(m,3H),1.64–1.51(m,6H),1.47(d,J＝6.9Hz,3H),1.29–1.24(m,13H),1.02(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.52,171.81,169.97,167.47,152.40,151.57,150.41,148.37,143.26,136.67,134.86,131.59,130.77,130.37,129.50,126.46,118.32,113.33,111.65,104.42,77.48,77.16,69.80,66.93,58.75,57.34,56.69,55.66,54.88,53.51,49.76,48.77,47.69,45.85,45.18,39.00,36.51,35.91,35.40,33.14,29.89,29.67,29.37,29.21,26.99,26.51,25.64,24.58,22.23,16.09,10.63,8.67.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₇H₈₄N₁₁O₇S]⁺1066.6270;found 1066.6302.

(10) Compounds numbered X-12 in Table 1

The title compound was prepared according to the procedure for example 8 in 47% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.99(s,1H),8.65(s,1H),7.75(t,J＝6.0Hz,1H),7.58(dd,J＝8.6,2.3Hz,1H),7.51(d,J＝7.9Hz,1H),7.36(d,J＝1.9Hz,4H),6.85–6.81(m,2H),6.28(d,J＝8.8Hz,1H),5.10–5.03(m,1H),4.75(d,J＝7.3Hz,1H),4.66(t,J＝7.8Hz,1H),4.57(d,J＝8.8Hz,1H),4.50–4.45(m,1H),4.22–4.13(m,1H),4.03–3.93(m,3H),3.82(s,3H),3.62(dd,J＝11.2,4.1Hz,1H),3.55–3.48(m,2H),3.39–3.34(m,2H),3.24–3.16(m,4H),3.00–2.84(m,4H),2.56–2.51(m,5H),2.49(s,3H),2.42–2.33(m,1H),2.12(t,J＝7.6Hz,2H),2.08–2.02(m,3H),1.63–1.50(m,6H),1.46(d,J＝6.9Hz,3H),1.28–1.21(m,17H),1.01(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.47,171.74,170.04,167.45,152.38,151.56,150.38,148.33,143.30,136.76,134.68,131.58,130.74,130.42,129.48,126.45,118.36,113.31,111.58,104.37,77.55,77.23,76.91,69.78,66.93,58.79,57.33,56.69,55.65,54.82,49.59,48.75,47.69,45.89,45.05,38.98,36.52,35.44,33.11,29.88,29.50,29.47,29.43,29.29,29.24,27.00,26.51,25.68,24.56,22.22,16.08,10.61,8.65.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₉H₈₈N₁₁O₇S]⁺1094.6583;found 1092.6616.

(11) Compounds numbered X-13 in Table 1

The title compound was prepared as a yellow solid in 37% yield by the procedure described in example 5.

¹H NMR(400MHz,Chloroform-d)δ10.72(s,1H),8.67(s,1H),7.52(d,J＝4.6Hz,1H),7.48(t,J＝6.0Hz,1H),7.44(dd,J＝8.6,2.3Hz,1H),7.35(s,4H),6.92(d,J＝2.3Hz,1H),6.85(d,J＝8.7Hz,1H),6.41(d,J＝9.0Hz,1H),5.63(d,J＝4.6Hz,1H),4.74–4.69(m,2H),4.60(d,J＝8.9Hz,1H),4.57–4.51(m,2H),4.34(dd,J＝15.0,5.3Hz,1H),4.24–4.15(m,1H),4.07–3.98(m,3H),3.86(s,3H),3.64(dd,J＝11.2,3.6Hz,1H),3.55–3.48(m,2H),3.14–3.00(m,4H),2.72–2.60(m,4H),2.52–2.49(m,5H),2.48–2.43(m,1H),2.37(t,J＝7.9Hz,2H),2.23–2.13(m,3H),2.10–2.04(m,2H),1.63–1.54(m,4H),1.50(d,J＝10.3Hz,2H),1.31–1.27(m,9H),0.95(s,9H).¹³C NMR(100MHz,Chloroform-d)δ173.66,171.74,171.07,170.36,152.39,151.91,151.04,150.37,148.38,138.18,136.31,135.74,131.64,130.84,130.65,129.46,128.04,117.82,112.63,112.56,105.07,69.80,66.91,58.79,57.30,56.93,55.66,53.48,50.89,47.65,46.02,43.17,36.41,36.29,35.31,33.13,29.69,29.00,28.85,27.23,26.43,25.45,24.54,16.07,10.51.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₃H₇₆N₁₁O₇S]⁺1010.5644;found 1010.5645.

(12) Compounds numbered X-15 in Table 1

The title compound was prepared according to the procedure for example 6 in 29% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),7.65(dd,J＝8.5,7.3Hz,1H),7.50(d,J＝4.6Hz,1H),7.46(dd,J＝8.6,2.3Hz,1H),7.42(d,J＝7.2Hz,1H),7.19(d,J＝8.5Hz,1H),6.89(d,J＝2.3Hz,1H),6.85(d,J＝8.6Hz,1H),5.60(d,J＝4.6Hz,1H),4.97–4.92(m,1H),4.74(d,J＝7.2Hz,1H),4.22–4.10(m,3H),4.04–3.97(m,2H),3.84(s,3H),3.55–3.46(m,2H),3.17–3.01(m,4H),2.89–2.64(m,7H),2.53–2.47(m,2H),2.46–2.41(m,2H),2.14–2.03(m,3H),1.91–1.82(m,2H),1.59–1.46(m,6H),1.39–1.31(m,6H),1.29–1.27(m,3H).¹³C NMR(100MHz,Chloroform-d)δ171.89,170.45,168.94,167.18,165.78,156.64,152.37,151.92,151.02,136.48,136.16,135.81,133.76,130.72,118.94,117.86,117.03,115.62,112.50,112.39,104.93,69.51,66.89,58.73,55.62,53.29,50.69,49.12,47.68,45.87,33.05,31.49,29.68,29.39,29.11,28.77,27.51,26.44,25.88,24.50,22.69,14.83,10.49,9.32.HRMS-ESI(m/z):[M+H]⁺calcd for[C₄₄H₅₈N₉O₈]⁺840.4403;found 840.4427.

(13) Compounds numbered X-16 in Table 1

The title compound was prepared according to the procedure for example 6 in a yellow solid yield of 37%.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),8.86(s,1H),7.78(d,J＝7.9Hz,1H),7.63(d,J＝7.4Hz,1H),7.53(d,J＝4.8Hz,1H),7.46–7.39(m,2H),6.92(d,J＝2.3Hz,1H),6.83(d,J＝8.7Hz,1H),5.59(d,J＝4.6Hz,1H),4.99(dd,J＝12.7,5.4Hz,1H),4.74(d,J＝7.2Hz,1H),4.40–4.31(s,2H),4.23–4.13(m,1H),4.04–3.96(m,2H),3.84(s,3H),3.55–3.46(m,2H),3.17–2.96(m,4H),2.76–2.61(m,5H),2.53–2.39(m,6H),2.11–2.03(m,3H),1.80–1.69(m,2H),1.62–1.51(m,4H),1.41–1.34(m,2H),1.32–1.24(m,5H).¹³C NMR(100MHz,Chloroform-d)δ172.30,172.00,170.42,169.15,152.38,151.95,151.04,136.15,135.80,134.11,133.29,132.58,130.82,126.26,117.88,112.54,105.07,66.88,58.25,55.67,53.28,52.07,50.61,47.68,36.43,34.50,33.09,31.92,29.70,26.93,26.05,25.34,24.53,23.11,10.50.HRMS-ESI(m/z):[M+H]⁺calcd for[C₄₂H₅₅N₁₀O₇]⁺811.4250;found 811.4273.

(14) Compounds numbered X-17 in Table 1

The title compound was prepared according to the procedure for example 6 in 43% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.72(s,1H),9.14(s,1H),7.74(d,J＝7.6Hz,1H),7.59(d,J＝7.1Hz,1H),7.52(s,1H),7.40(d,J＝8.9Hz,2H),6.90(s,1H),6.80(d,J＝8.6Hz,1H),5.83(s,1H),5.10–5.01(m,1H),4.87(d,J＝6.8Hz,1H),4.50–4.25(m,2H),4.14(s,1H),4.02–3.93(m,2H),3.80(s,3H),3.47(t,J＝10.9Hz,2H),3.19–3.02(m,4H),2.97(q,J＝7.3Hz,1H),2.92–2.70(m,4H),2.69–2.60(m,1H),2.53–2.41(m,5H),2.07–1.96(m,3H),1.72–1.61(m,2H),1.59–1.46(m,4H),1.33–1.18(m,11H).¹³C NMR(100MHz,Chloroform-d)δ172.67,172.51,170.69,170.53,169.28,152.34,151.97,150.95,136.13,135.50,134.28,133.41,132.47,131.12,118.10,112.35,104.97,66.86,55.69,53.55,53.01,49.90,47.68,45.98,32.94,29.68,28.96,27.07,25.56,24.50,10.50,8.86.HRMS-ESI(m/z):[M+H]⁺calcd for[C₄₄H₅₉N₁₀O₇]⁺839.4563;found 839.4581.

(15) Compounds numbered X-18 in Table 1

The title compound was prepared according to the procedure for example 6 in a yellow solid yield of 38%.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),8.62(s,1H),7.68(t,J＝6.1Hz,2H),7.56–7.50(m,1H),7.49–7.43(m,2H),6.90(s,1H),6.85(d,J＝8.7Hz,1H),5.43–5.37(m,1H),5.17(dd,J＝13.5,5.5Hz,1H),4.72(d,J＝7.3Hz,1H),4.50(d,J＝16.8Hz,1H),4.35(d,J＝16.6Hz,1H),4.24–4.15(m,1H),4.03(d,J＝11.3Hz,2H),3.86(s,3H),3.53(t,J＝11.5Hz,2H),3.17–3.05(m,5H),2.88–2.71(m,4H),2.57–2.44(m,6H),2.18–2.07(m,3H),1.73(p,J＝7.4Hz,2H),1.62–1.52(m,4H),1.42–1.29(m,15H).¹³C NMR(100MHz,Chloroform-d)δ172.48,172.36,170.59,170.41,169.23,152.34,151.96,151.04,136.03,135.84,134.44,133.22,132.54,130.84,128.93,126.42,120.58,117.92,112.58,112.49,105.04,66.88,62.51,58.45,55.66,53.14,51.76,50.45,47.65,46.72,45.84,36.74,33.06,32.58,31.61,29.70,29.32,29.24,29.18,27.35,26.11,25.68,24.54,23.33,10.50,9.40.HRMS-ESI(m/z):[M+H]⁺calcd for[C₄₆H₆₃N₁₀O₇]⁺867.4876;found 867.4902.

(16) Compounds numbered X-20 in Table 1

The title compound was prepared according to the procedure for example 10 in 49% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.72(s,1H),8.65(s,1H),7.67(d,J＝7.7Hz,1H),7.50(d,J＝4.4Hz,1H),7.42(dd,J＝8.6,2.3Hz,1H),7.38(d,J＝4.5Hz,1H),7.37–7.32(m,4H),6.89(d,J＝2.3Hz,1H),6.82(d,J＝8.6Hz,1H),5.77(d,J＝4.4Hz,1H),5.06(p,J＝7.0Hz,1H),4.77–4.69(m,2H),4.60(d,J＝8.9Hz,1H),4.21–4.12(m,1H),4.03–3.95(m,5H),3.83(s,3H),3.74–3.58(m,13H),3.52–3.45(m,2H),3.25–3.16(m,1H),3.09–3.01(m,4H),2.74–2.65(m,4H),2.53–2.47(m,6H),2.42–2.34(m,1H),2.05–2.01(m,2H),1.60–1.50(m,2H),1.46(d,J＝6.9Hz,3H),1.26(t,J＝7.4Hz,3H),1.04(s,9H).¹³C NMR(100MHz,CDCl₃)δ171.17,170.38,170.20,170.12,152.37,151.90,151.01,150.36,148.33,143.41,136.27,135.74,131.65,130.67,130.65,129.46,127.84,126.40,117.85,112.61,112.53,105.07,76.92,71.11,70.60,70.43,70.32,69.81,68.72,66.89,58.75,57.81,56.95,56.77,55.64,53.81,50.81,48.80,47.64,46.09,36.02,35.50,33.08,26.49,24.51,22.33,16.07,11.36,10.53.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₄H₇₈N₁₁O₁₀S]⁺1072.5648;found 1072.6564.

(17) Compounds numbered X-21 in Table 1

The title compound was prepared according to the procedure for example 10 in a yellow solid yield of 16%.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),8.69(s,1H),7.92(d,J＝8.6Hz,1H),7.55–7.50(m,2H),7.50–7.47(m,1H),7.43–7.36(m,4H),6.91(d,J＝2.3Hz,1H),6.86(d,J＝8.6Hz,1H),5.42(d,J＝4.6Hz,1H),5.08(q,J＝7.2Hz,1H),4.76(t,J＝7.9Hz,1H),4.69(d,J＝7.3Hz,1H),4.50(d,J＝8.7Hz,2H),4.25–4.18(m,1H),4.14(d,J＝11.3Hz,1H),4.06–4.00(m,2H),3.88(s,3H),3.62(dd,J＝11.3,3.8Hz,1H),3.57–3.49(m,2H),3.15–3.01(m,6H),2.77–2.69(m,4H),2.67–2.55(m,12H),2.54–2.51(m,5H),2.15–2.02(m,4H),1.62–1.54(m,2H),1.50(d,J＝6.9Hz,3H),1.30(t,J＝7.4Hz,3H),1.08(s,9H).¹³C NMR(100MHz,CDCl₃)δ171.53,170.98,170.32,169.88,152.40,151.92,151.05,150.37,148.44,143.25,136.21,135.80,131.64,130.79,130.65,129.55,126.43,117.83,112.64,112.51,105.03,69.97,66.93,61.12,58.39,57.22,55.69,53.90,53.78,53.44,50.89,48.87,47.68,35.55,34.92,33.15,29.71,26.56,24.55,22.32,16.12,10.52.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₄H₇₈N₁₃O₇S]⁺1052.5862;found 1052.5852.

(18) Compounds numbered X-22 in Table 1

The title compound was prepared according to the procedure for example 10 in 45% yield as yellow solid.

¹H NMR(400MHz,Chloroform-d)δ10.73(s,1H),8.68(s,1H),7.97(d,J＝8.5Hz,1H),7.60(d,J＝7.8Hz,1H),7.52(d,J＝4.6Hz,1H),7.47(dd,J＝8.6,2.3Hz,1H),7.41–7.36(m,4H),6.91(d,J＝2.3Hz,1H),6.86(d,J＝8.7Hz,1H),5.54–5.48(m,1H),5.12–5.05(m,1H),4.77(t,J＝7.8Hz,1H),4.70(d,J＝7.4Hz,1H),4.49(d,J＝8.6Hz,1H),4.25–4.15(m,1H),4.15–4.10(m,1H),4.04–3.99(m,2H),3.87(s,3H),3.63(dd,J＝11.3,4.2Hz,1H),3.55–3.49(m,2H),3.14–3.03(m,4H),2.89–2.77(m,4H),2.71–2.62(m,4H),2.56–2.47(m,7H),2.44(t,J＝6.8Hz,2H),2.18(dd,J＝31.8,10.9Hz,2H),2.11–2.03(m,4H),1.74(t,J＝11.6Hz,2H),1.64–1.50(m,4H),1.49(d,J＝7.0Hz,3H),1.30(t,J＝7.3Hz,5H),1.08(s,9H).¹³C NMR(100MHz,CDCl₃)δ171.61,171.39,170.36,169.89,152.38,151.93,151.04,150.44,148.41,143.33,135.99,135.87,131.67,130.71,129.53,126.44,117.98,112.64,112.47,105.01,69.97,66.91,58.36,57.24,55.95,55.68,54.29,53.10,50.33,48.86,47.67,45.14,34.89,33.63,33.15,32.68,26.54,24.55,22.33,16.10,10.51,8.70.HRMS-ESI(m/z):[M+H]⁺calcd for[C₅₅H₇₈N₁₂O₇S]⁺1051.5910;found 1051.5922.

The chemical structures of the above synthesized target compounds of the present invention are shown in table 1. Other compounds of Table 1 can be prepared by the methods described above.

EXAMPLE 13 biological Activity test of PROTAC class of Compounds targeting degradation of FLT3-ITD muteins

(1) Cell inhibition activity test of PROTAC class compounds of targeted degradation FLT3-ITD mutant proteins:

Drug IC ₅₀ values were tested using the CCK-8 assay. In the experiment, cells in the logarithmic phase were first taken. After centrifugation at 1000rpm for 5min, the supernatant was discarded. Cells were resuspended in complete medium containing 10% fbs. After subsequent cell counting and cell concentration adjustment, cells were seeded in 96-well plates at a density of 10000 per well. And the drug concentration gradient was adjusted to 0,0.1,1,5, 10, 20, 50, 100, 500, 1000nM, the total volume of medium per well was 100. Mu.L, at least 3 duplicate wells were set, the cell-free wells were completely medium as a blank, and the 96-well plate periphery was filled with sterile PBS. At 72h of cell culture, 10. Mu. L Cell Counting Kit 8 (CCK-8) solution was added to each well, and the cells were mixed and then returned to the cell incubator for culture. After 1-4h incubation, cells were removed (avoiding contamination), absorbance (OD) per well at 450nm wavelength was measured using a multifunctional microplate reader, and drug IC ₅₀ values were calculated.

(2) Cell degradation activity test of PROTAC class compounds targeted to degrade FLT3-ITD muteins:

cell surface FLT3 protein expression was detected by flow cytometry. Cells in the logarithmic growth phase were harvested in the experiment, centrifuged at 1000rpm for 5min, and the supernatant was discarded and the cells were resuspended in sterile PBS. After subsequent cell counting and cell concentration adjustment, cells were seeded at a density of 5×105 cells/well in six well plates. The concentration gradient of the drug is adjusted to 0,1, 10 and 100nM, the total volume of each hole is 2mL, at least 3 compound holes are arranged, and the mixture is placed in an incubator for incubation for 12h. The cells were pelleted by centrifugation at 1000rpm for 5min and the supernatant discarded. The cells were resuspended in 50. Mu.L of PBS, washed 1-2 times with PBS, the supernatant was discarded, and the appropriate concentration of the streaming antibody CD135 was added and incubated for 30min at room temperature in the absence of light. The cells were pelleted by centrifugation at 1000rpm for 5min and the supernatant discarded. 400. Mu.L PBS was added to each tube for resuspension. After filtration, the apoptosis rate is detected by a flow cytometer.

The invention uses gelitinib and its derivative 9 as control, and tests the cell inhibition activity (IC ₅₀) and the protein degradation activity of the synthesized compound, the cell inhibition activity result is shown in Table 2, and the protein degradation activity is shown in figure 1. Wherein the MOLM-13 cell line carries FLT3-ITD mutant human acute myelogenous leukemia cell line, and all activity results are calculated in nM.

Table 2: results of cytostatic Activity of some of the compounds synthesized according to the present invention

From the above results of biological activity, it can be seen that most of the compounds have excellent cytostatic activity, IC ₅₀ can reach nanomolar level, and the activity of compound X-22 is equivalent to that of the control drug, namely, gilitanid. On the other hand, in the degradation activity test, most compounds, especially PROTAC molecules based on VHL ligand with methyl, can be seen to show excellent protein degradation capability, and can provide a new idea for treating AML as a novel degradation agent.

Finally, it is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. The PROTAC compound for targeted degradation of FLT3-ITD mutant protein is characterized in that PROTAC compound for targeted degradation of FLT3-ITD mutant protein comprises one of the following compounds X3, X4, X5, X6, X7, X8, X13, X14, X15, X16, X17, X18, X20, X21 and X22, and the structural formula is as follows:

；；

；

；。

2. An anti-AML pharmaceutical composition comprising a compound of the PROTAC class which is a target-degrading FLT3-ITD mutein according to claim 1 or a pharmacologically or physiologically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

3. Use of a compound of the PROTAC class of targeted degradation FLT3-ITD muteins according to claim 1 or an anti-AML pharmaceutical composition according to claim 2 for the preparation of an anti-AML medicament.