PD-L1 protein degradation agent with silicon-containing group as hydrophobic label as well as preparation method, pharmaceutical composition and application of PD-L1 protein degradation agent

Abstract

The invention belongs to the field of chemical drugs, and discloses a PD-L1 protein degradation agent taking a silicon-containing group as a hydrophobic label, and a preparation method, a pharmaceutical composition and application thereof. The structure of the PD-L1 protein degradation agent taking the silicon-containing group as the hydrophobic label is as shown in formula I, and linker is a saturated aliphatic chain, an unsaturated aliphatic chain, a connecting structure consisting of an aromatic ring and a saturated aliphatic chain or a connecting structure consisting of an aromatic ring and an unsaturated aliphatic chain; r is a specific silicon-containing group as a hydrophobic label. The PD-L1 protein degradation agent with the silicon-containing group as the hydrophobic label is obtained, the preparation process is simple and easy to implement, and the obtained PD-L1 protein degradation agent has high liver microsome metabolism stability and considerable oral bioavailability, shows an efficient treatment effect in an in-vivo experiment, has a certain inhibition effect on proliferation of various tumor cells, and has a good application prospect in the fields of liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism, liver microsome metabolism and liver microsome metabolism. The compound is suitable for developing drugs for treating leukemia and other cancers. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of chemical medicines, and specifically relates to a PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag, a preparation method thereof, a pharmaceutical composition and application thereof. Background Art

[0002] Immune checkpoint blocking antibodies targeting programmed death protein 1 (PD-1) / programmed cell death ligand 1 (PD-L1) interaction have achieved considerable clinical success. So far, the U.S. Food and Drug Administration (FDA) has approved several monoclonal antibodies that block the interaction between PD-1 and PD-L1 immune checkpoint proteins. In addition, some small molecules targeting PD-1 / PD-L1 interaction, such as macrocyclic peptides, peptides, peptide mimetics, and non-peptide structures, have been reported recently. However, some inherent defects of antibody drugs, such as immune-related adverse events, poor pharmacokinetic (PK) properties, poor tumor tissue penetration, and high production costs, have hindered their wider clinical application. In addition, the cytoplasmic region of PD-L1 is involved in intracellular signaling that promotes tumor cell proliferation, which suggests that regulating the PD-1 / PD-L1 interaction by inhibitors alone may not be sufficient to achieve the desired anti-tumor efficacy. Therefore, the development of PD-L1 degraders may be an effective strategy.

[0003] The hydrophobic tag (Hyt) bifunctional molecule consists of three parts: target protein ligand, linker, and hydrophobic group. By connecting a large and hydrophobic group to a small molecule that can bind to the target, such a two-headed molecule will be mistakenly identified as a misfolded part of the target protein by the intracellular protein repair mechanism after binding to the target, and then it can be folded by the chaperone protein and then degraded by the proteasome. The hydrophobic group in the Hyt molecule often has a small molecular weight, so it may have higher solubility and drugability. At present, the research and development of degraders based on hydrophobic tags is still in the exploratory stage. On the one hand, there are few reported hydrophobic tag fragments, and there is still a lot of room for optimization in degradation activity and physicochemical properties. On the other hand, the exact degradation mechanism has not yet been clarified. Therefore, it is very important to explore more hydrophobic fragments with high activity and excellent physicochemical properties and clarify their corresponding degradation mechanisms for the development of hydrophobic tag fragments towards clinical applications.

[0004] The hydrophobic fragments used in the hydrophobic tag degraders that have been reported so far include adamantane, menthol, norbornene, Boc arginine, carborane, fluorenyl, etc. However, the degradation effects of these conventional hydrophobic tag degraders are relatively low, their metabolic stability in liver microsomes is poor, and their solubility is poor and difficult to be taken orally, making them difficult to be used for further clinical treatment and development. The development of new hydrophobic tag degraders with better liver microsome stability and oral administration is needed to meet clinical needs. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies of the prior art and provide a PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag, which has high metabolic stability in liver microsomes and can be orally administered, and a preparation method, a pharmaceutical composition and application thereof. Based on this, the first aspect of the present invention provides a PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag, and its structure is shown in Formula I:

[0006]

[0007] Wherein, linker is a saturated fatty chain, an unsaturated fatty chain, a linking structure consisting of an aromatic ring and a saturated fatty chain, or a linking structure consisting of an aromatic ring and an unsaturated fatty chain; R is trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, isopropyldimethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, cyclohexyldimethylsilyl, vinyldimethylsilyl, trimethoxysilyl, triethoxysilyl, phenylvinylmethylsilyl or triphenylsilyl.

[0008] The present invention provides a PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag. In a bifunctional molecule, the silicon-containing group is used as a hydrophobic tag and the BMS-37 mother core is used as a target protein ligand, thereby obtaining a protein degrader that can effectively degrade PD-L1. The PD-L1 protein degrader prepared by the present invention can effectively induce the degradation of PD-L1 in the human acute myeloid leukemia cell line kasumi-1 in a dose-dependent and time-dependent manner, has considerable liver microsome stability and bioavailability, and exhibits excellent in vivo anticancer effects.

[0009] Among them, Linker is a saturated fatty chain, an unsaturated fatty chain, a connection structure composed of an aromatic ring and a saturated fatty chain, or a connection structure composed of an aromatic ring and an unsaturated fatty chain. By selecting ideal linkers of different types and lengths, the purpose of not affecting the binding of the two proteins in space but maintaining their binding can be achieved. Based on this, in some more preferred implementations, the structure of the PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag is shown in Formula II or Formula III:

[0010]

[0011] wherein m and n are independently selected from integers in the range of 1-9.

[0012] When the structure of the above-mentioned PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag is as shown in Formula IV, it can effectively induce the degradation of PD-L1 in the human acute myeloid leukemia cell line kasumi-1 in a dose-dependent and time-dependent manner, has considerable liver microsomal stability and bioavailability, and exhibits excellent in vivo anti-leukemia effects.

[0013]

[0014] The second aspect of the present invention provides a method for preparing the above-mentioned PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag. When the structure of the above-mentioned PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag is shown in Formula II, its preparation method is shown in Scheme 1; when the structure of the above-mentioned PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag is shown in Formula III, its preparation method is shown in Scheme 2;

[0015] Route 1: tert-Butyldiphenylsilyl chloride (compound B) and ethyl azide (compound A) are reacted with imidazole to obtain intermediate C, and compound D and compound E are reacted with Mitsunobu reaction to obtain intermediate F, which is then subjected to reductive amination reaction with alkynylamines of different lengths to obtain intermediates G1-G5, and intermediate C and intermediates G1-G5 undergo click reaction to obtain final products 1-5.

[0016]

[0017] Route 2: Compound B and compound H1-H4 are reacted with imidazole to obtain intermediates I1-I4, which are then subjected to reductive amination reaction with compound F to obtain the final product 6-9.

[0018]

[0019] The preparation method of the invention has a simple route, the raw materials used are cheap and easily available, and the overall reaction yield is high.

[0020] The PD-L1 protein degrader or a pharmaceutically acceptable salt thereof using a silicon-containing group as a hydrophobic tag can be used to prepare a drug for treating related cancers with abnormal PD-L1. The above-mentioned related cancers include: leukemia, melanoma, lung cancer, gastric cancer, breast cancer, colorectal cancer, and pancreatic cancer. More preferably, the related cancer is leukemia.

[0021] The third aspect of the present invention provides a pharmaceutical composition, comprising the above-mentioned PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag or a pharmaceutically acceptable salt thereof (or, the above-mentioned PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag or a pharmaceutically acceptable salt thereof as the main active ingredient). In some preferred implementations, the above-mentioned pharmaceutical composition may also include at least one of an excipient, a solvent and a pharmaceutical carrier. Among them, the excipient is at least one of gum arabic, syrup, lanolin and starch; it has no incompatibility with the main drug, does not produce side effects, does not affect the efficacy, is not easy to deform, crack, mildew, or be worm-eaten at room temperature, is harmless to the human body, has no physiological effect, does not produce chemical or physical effects with the main drug, and does not affect the content determination of the main drug. The solvent can be water, glycerol or ethanol.

[0022] The beneficial effects of the present invention are as follows: the present invention obtains a PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag, the preparation process is simple and easy, the obtained PD-L1 protein degrader has high liver microsome metabolic stability, has considerable oral bioavailability, shows a high therapeutic effect in in vivo experiments, has a certain inhibitory effect on the proliferation of various tumor cells, and is suitable for the development of drugs for the treatment of leukemia and other cancers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The graph shows the concentration-dependent degradation of PD-L1 in human acute myeloid leukemia cell line kasumi-1 by compound 1; (A) is a Western Blot graph, (B) is a DC 50 picture;

[0024] Figure 2 Shown is the effect of compound 1 on time-dependent degradation of PD-L1 in the human acute myeloid leukemia cell line kasumi-1. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments and drawings to clearly and completely describe the concept and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0026] Example 1

[0027] A PD-L1 protein degrader (denoted as compound 1-5) with a silicon-containing group as a hydrophobic tag, and its structures are shown below:

[0028]

[0029] The structures of the intermediate compound A, compound B, compound C, compound D, compound E, compound F, propargylamine, but-3-yn-1-amine, pent-4-yn-1-amine, hex-5-yn-1-amine, hept-6-yn-1-amine, and compounds G1-G5 are shown below:

[0030]

[0031]

[0032] The specific preparation method is:

[0033] 1) Preparation of compound C:

[0034] Under an ice bath, compound A (174 mg, 2.00 mmol) was dissolved in dichloromethane (12 mL), and compound B (825 mg, 3.00 mmol) and imidazole (408 mg, 6.00 mmol) were added respectively. The ice bath was removed after 30 minutes, and the mixture was stirred at room temperature overnight. The solid was filtered out, and the remaining organic phase was dried over anhydrous sodium sulfate, concentrated, and subjected to silica gel flash column chromatography (petroleum ether: ethyl acetate = 60:1) to obtain compound C.

[0035] Compound C was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.72–7.66(m,4H),7.41(tt,J=8.1,5.7Hz,6H),3.81(dd,J=5.5,4.6Hz,2H),3.29(t,J=5.0Hz,2H),1.07(s,9H). 13 C NMR (100MHz, CDCl3) δ135.6,133.1,129.9,127.8,63.3,53.2,26.7,19.1.

[0036] 2) Preparation of compound F:

[0037] Under an ice bath, compound D (1.98 g, 10.0 mmol) and compound E (1.82 g, 10.0 mmol) were dissolved in tetrahydrofuran (30 mL), and triphenylphosphine (2.62 g, 10.0 mmol) was added, and then diisopropyl azodicarboxylate (4.04 g, 20.0 mmol) was added dropwise to the reaction system. After the reaction was completed, it was diluted with water (50 mL), and extracted with ethyl acetate (3×50 mL). The organic phases were then combined and the reaction solution was washed with saturated NaCl solution (50 mL). The organic phase was dried over anhydrous sodium sulfate and concentrated. The crude product was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 4:1) to obtain compound F.

[0038] Compound F was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.46–7.40(m,2H),7.40–7.32(m,5H),7.21(ddt,J=6.8, 2.2, 0.9Hz, 1H), 6.40 (s, 2H), 5.15 (d, J = 0.9Hz, 2H), 3.89 (s, 6H), 2.30 (s, 3H).

[0039] 3) Preparation of compounds G1-G5:

[0040] Preparation of compound G1:

[0041] Under an ice bath, compound F (362 mg, 1.00 mmol) and acetic acid (60.1 mg, 1.00 mmol) were dissolved in dichloromethane (12 mL), and propargylamine (82.5 mg, 1.50 mmol) was added to the reaction system. After one hour, sodium cyanoborohydride (126 mg, 2.00 mmol) was slowly added, and the reaction system was reacted at room temperature overnight. After the reaction, it was diluted with water (10 mL) and extracted with dichloromethane (3×10 mL). The organic phases were then combined and dried over anhydrous sodium sulfate and concentrated. The crude product was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 2:1) to obtain compound G1.

[0042] Compound G1 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.55–7.20(m,8H),6.33–6.15(m,3H),5.09(s,2H),4.19(s,2H),3.84(s,6H),3.63(s,2H),2.43(s,1H),2.27(s,3H). 13 C NMR (100MHz, CDCl3) δ161.7,159.8,143.2,141.9,134.8,134.6,130.5,129.5,12 8.4,128.2,127.0,125.8,101.6,91.3,76.3,75.4,69.5,55.9,39.8,36.1,16.3.

[0043] Preparation of compound G2:

[0044] Compound G2 was obtained by replacing compound propargylamine with compound but-3-yn-1-amine (104 mg, 1.50 mmol) in the same manner as for preparing compound G1.

[0045] Compound G2 was tested, and the test results were as follows:1 H NMR (400MHz, CDCl3) δ7.52–7.20(m,8H),6.27(s,2H),5.10(s,2H),4.26(s,2H),3. 87(s,6H),3.04(t,J=7.3Hz,2H),2.72(d,J=7.4Hz,2H),2.27(s,3H),2.09(s,1H). 13 C NMR (100MHz, CDCl3) δ176.7,162.1,159.8,143.1,141.8,134.6,134.6,130.5,129.4,128 .4,128.2,127.0,125.7,99.4,91.2,79.1,71.7,69.5,55.9,44.6,40.5,23.0,16.5,16.3.

[0046] Preparation of compound G3:

[0047] Compound G3 was obtained by replacing compound propargylamine with compound pent-4-yn-1-amine (125 mg, 1.50 mmol) in the same manner as for preparing compound G1.

[0048] Compound G3 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.50–7.21(m,8H),6.26(s,2H),5.10(s,2H),4.21(s,2H),3.89(s,6H),3.0 2(t,J=7.7Hz,2H),2.35–2.28(m,2H),2.27(s,3H),1.99(t,J=4.1Hz,3H),1.26(d,J=6.4Hz,2H). 13 C NMR (100MHz, CDCl3) δ162.4,159.9,143.2,141.9,134.7,130.6,129.5,128.5,128.2, 127.1,125.8,98.6,91.3,81.9,70.5,69.6,56.1,45.7,40.5,24.1,22.1,16.4,16.1.

[0049] Preparation of compound G4:

[0050] Compound G4 was obtained by replacing compound propargylamine with compound hex-5-yn-1-amine (146 mg, 1.50 mmol) in the same manner as for preparing compound G1.

[0051] Compound G4 was tested, and the test results are as follows: 1H NMR (400MHz, CDCl3) δ7.48–7.40(m,2H),7.40–7.31(m,5H),7.21(ddt,J=6.8,2.1,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.00(d,J=5.8Hz, 2H),3.90(s,6H),2.76(dt,J=5.0,4.3Hz,2H),2.66–2.55(m,1H),2.43(td ,J=5.7,3.0Hz,2H),2.30(s,3H),2.05(t,J=3.0Hz,1H),1.67–1.43(m,4H).

[0052] Preparation of compound G5:

[0053] Compound G5 was obtained by replacing compound propargylamine with compound hept-6-yn-1-amine (167 mg, 1.50 mmol) in the same manner as compound G1.

[0054] Compound G5 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.50–7.40(m,2H),7.40–7.31(m,5H),7.21(ddt,J=6.8,2. 1,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.00(d,J=5.8Hz,2H),3.90(s ,6H),2.72(q,J=5.2Hz,2H),2.60(tt,J=5.7,4.8Hz,1H),2.30(s,3H),2.11(td, J=5.9,3.0Hz,2H),2.04(t,J=3.0Hz,1H),1.64–1.47(m,4H),1.43–1.33(m,2H).

[0055] 4) Preparation of compound 1-5:

[0056] Preparation of compound 1:

[0057] G1 (92.3 mg, 0.230 mmol) and compound C (91.1 mg, 0.280 mmol) were dissolved in a mixed solvent of t-BuOH / H2O (5 mL, 1:1), and CuSO4·5H2O (18.6 mg, 0.116 mmol) and sodium L-ascorbate (38.4 mg, 0.194 mmol) were added. The mixture was reacted at room temperature overnight. After the reaction was completed, CuSO4·5H2O was filtered out, and the filtrate was concentrated in vacuo and separated by silica gel flash column chromatography (dichloromethane:methanol=30:1) to obtain compound 1.

[0058] Compound 1 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.64–7.17(m,19H),6.25(d,J=11.2Hz,2H),5.10(d,J=13.3Hz,2H),4.56–4.38(m,2 H),4.26(d,J=18.6Hz,1H),4.18–3.94(m,5H),3.81(d,J=9.2Hz,6H),2.28(d,J=7.4Hz,3H),1.00(s,9H). 13 C NMR (100MHz, CDCl3) δ143.1,141.9,135.5,135.5,135.0,134.8,134.5,132.7,130.5,130.4,130.1,130.0,129.4,1 28.4,128.4,128.1,128.0,127.9,127.0,126.9,125.7,125.7,91.3,69.5,62.5,55.9,29.8,26.9,26.8,19.2,16.3.

[0059] Preparation of compound 2:

[0060] Compound 2 was obtained by the same method as that for preparing Compound 1 except that Compound G1 was replaced by Compound G2 (95.6 mg, 0.230 mmol).

[0061] Compound 2 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.53–7.24(m,19H),6.25(s,2H),5.08(s,2H),4.43(s,2H),4.24 (s,2H),3.97(s,2H),3.85(s,6H),3.15(s,4H),2.26(s,3H),1.26(s,1H),1.00(s,9H). 13 C NMR (100MHz, CDCl3) δ159.8,143.2,141.9,135.5,134.8,134.6,132.6,130.6,130.2,129. 5,128.5,128.2,128.0,127.0,125.8,91.3,69.5,62.6,56.0,29.8,26.8,22.6,19.2,16.4.

[0062] Preparation of compound 3:

[0063] Compound 3 was obtained by the same method as that for preparing Compound 1 except that Compound G1 was replaced by Compound G3 (98.8 mg, 0.230 mmol).

[0064] Compound 3 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.56–7.25(m,19H),6.23(s,2H),5.08(s,2H),4.41(t,J=5.3Hz,2H),4.17(s,2H),3.97(t,J=5. 2Hz,2H),3.84(s,6H),2.93(t,J=6.9Hz,2H),2.81(t,J=7.0Hz,2H),2.26(s,3H),2.18(t,J=6.9Hz,2H),1.00(s,9H). 13 C NMR (100MHz, CDCl3) δ160.0,143.2,141.9,135.5,134.8,134.7,132.7,130.6,130.1,129.5,1 28.5,128.2,128.0,127.0,125.8,91.2,69.5,62.7,56.0,52.5,29.8,26.8,23.1,19.2,16.4.

[0065] Preparation of compound 4:

[0066] Compound 4 was obtained by replacing Compound G1 with Compound G4 (102 mg, 0.230 mmol) in the same manner as for preparing Compound 1.

[0067] Compound 4 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.64–7.57(m,4H),7.48(s,1H),7.46–7.40(m,2H),7.40–7.33(m,11H),7. 21(ddt,J=6.8,2.2,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.31(t,J=4.1Hz,2H),4.18 (t,J=4.1Hz,2H),4.00(d,J=5.8Hz,2H),3.90(s,6H),2.83–2.70(m,4H),2.61(tt,J=5.8,4.9Hz ,1H),2.30(s,3H),1.79(pd,J=7.7,0.7Hz,2H),1.64(ttd,J=8.1,5.1,0.8Hz,2H),1.03(s,9H).

[0068] Preparation of compound 5:

[0069] Compound 5 was obtained by replacing Compound G1 with Compound G5 (105 mg, 0.230 mmol) in the same manner as for preparing Compound 1.

[0070] Compound 5 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.65–7.58(m,4H),7.48(s,1H),7.46–7.40(m,2H),7.40–7.32(m,11H),7.2 1(ddt,J=6.8,2.2,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.31(t,J=4.1Hz,2H),4.18(t, J=4.1Hz,2H),4.00(d,J=5.8Hz,2H),3.90(s,6H),2.80–2.66(m,4H),2.60(tt,J=5.7,4.8Hz,1H) ,2.30(s,3H),1.80(p,J=8.0Hz,2H),1.62–1.50(m,2H),1.41(pd,J=7.5,0.9Hz,2H),1.03(s,9H).

[0071] Example 2

[0072] A PD-L1 protein degrader (denoted as compound 6-9) with a silicon-containing group as a hydrophobic tag, the structures of which are shown below:

[0073]

[0074] The structures of the intermediate compounds H1-H4, compound B, compound I1-I4, and compound F used are shown below:

[0075]

[0076] The specific preparation method is:

[0077] 1) Preparation of compounds I1-I4:

[0078] Preparation of compound I1:

[0079] Under an ice bath, compound H1 (150 mg, 2.00 mmol) was dissolved in dichloromethane (12 mL), and compound B (825 mg, 3.00 mmol) and imidazole (408 mg, 6.00 mmol) were added respectively. The ice bath was removed after 30 minutes, and the mixture was stirred at room temperature overnight. The solid was filtered out, and the remaining organic phase was dried over anhydrous sodium sulfate, concentrated, and subjected to silica gel flash column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain compound I1.

[0080] Compound I1 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.70–7.50(m,4H),7.45–7.29(m,6H),3.73(t,J=5.7Hz,2H),2. 93(tt,J=6.4,5.5Hz,2H), 1.74(p,J=5.6Hz,2H), 1.48(t,J=6.4Hz,2H), 1.03(s,9H).

[0081] Preparation of compound I2:

[0082] According to the same method for preparing compound I1, compound I2 was obtained by replacing compound H1 with compound H2 (178 mg, 1.50 mmol).

[0083] Compound I2 was tested, and the test results were as follows: 1 H NMR(400MHz, CDCl3)δ7.79–7.47(m,4H),7.46–7.23(m,6H),3.77–3.55(m,2H ),2.95–2.61(m,2H),1.81(t,J=6.5Hz,2H),1.70–1.40(m,4H),1.03(s,9H).

[0084] Preparation of compound I3:

[0085] According to the same method for preparing compound I1, compound I3 was obtained by replacing compound H1 with compound H3 (206 mg, 1.50 mmol).

[0086] Compound I3 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.80–7.49(m,4H),7.53–7.21(m,6H),3.67(t,J=6.0Hz,2H), 2.66(tt,J=6.5,5.2Hz,2H), 1.78(t,J=6.5Hz,2H), 1.61–1.26(m,6H), 1.03(s,9H).

[0087] Preparation of compound I4:

[0088] According to the same method for preparing compound I1, compound I4 was obtained by replacing compound H1 with compound H4 (234 mg, 1.50 mmol).

[0089] Compound I4 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.68–7.51(m,4H),7.47–7.10(m,6H),3.68(t,J=6.0Hz,2H), 2.67(tt,J=6.5,5.2Hz,2H),1.78(t,J=6.5Hz,2H),1.68–1.25(m,8H),1.03(s,9H).

[0090] 2) Preparation of compound 6-9:

[0091] Preparation of compound 6:

[0092] Under an ice bath, compound F (181 mg, 0.500 mmol) and acetic acid (30.0 mg, 0.500 mmol) were dissolved in dichloromethane (5 mL), and compound I1 (235 mg, 0.750 mmol) was added to the reaction system. One hour later, sodium cyanoborohydride (63.2 mg, 1.00 mmol) was slowly added, and the reaction system was reacted at room temperature overnight. After the reaction, it was diluted with water (8 mL) and extracted with dichloromethane (3×8 mL). The organic phases were then combined and dried over anhydrous sodium sulfate and concentrated. The crude product was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 5:1) to obtain compound 6.

[0093] Compound 6 was tested, and the test results were as follows: 1 H NMR(400MHz, CDCl3)δ7.71–7.58(m,4H),7.48–7.40(m,2H),7.40–7.31(m,11H) ,7.21(ddt,J=6.8,2.2,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.01(d ,J=5.9Hz,2H),3.90(s,6H),3.70(t,J=5.9Hz,2H),2.95(tt,J=5.8,4.9Hz,1H) ,2.78(td,J=5.6,4.9Hz,2H),2.30(s,3H),1.76(p,J=5.8Hz,2H),1.03(s,9H).

[0094] Preparation of compound 7:

[0095] Compound 7 was obtained by replacing compound I1 with compound I2 (246 mg, 0.750 mmol) according to the same method as that for preparing compound 6.

[0096] Compound 7 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.68–7.57(m,4H),7.46–7.40(m,2H),7.40–7.32(m,11 H),7.21(ddt,J=6.8,2.2,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4. 00(d,J=5.9Hz,2H),3.90(s,6H),3.71(t,J=5.7Hz,2H),2.75(q,J=5.1Hz,2H ), 2.60(tt,J=5.7,4.8Hz,1H),2.30(s,3H),1.74–1.56(m,4H),1.03(s,9H).

[0097] Preparation of compound 8:

[0098] Compound 8 was obtained by replacing compound I1 with compound I3 (256 mg, 0.750 mmol) according to the same method as that for preparing compound 6.

[0099] Compound 8 was tested, and the test results are as follows: 1 H NMR (400MHz, CDCl3) δ7.67–7.58(m,4H),7.49–7.40(m,2H),7.40–7.32(m,11H),7.21(ddt ,J=6.8,2.2,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.00(d,J=5.9Hz,2H),3.90( s,6H),3.67(t,J=6.0Hz,2H),2.72(q,J=5.2Hz,2H),2.60(tt,J=5.7,4.8Hz,1H),2.30(s, 3H), 1.56 (dddd, J=13.0, 10.4, 6.8, 5.6Hz, 4H), 1.38 (pd, J=7.3, 1.1Hz, 2H), 1.03 (s, 9H).

[0100] Preparation of compound 9:

[0101] Compound 9 was obtained by replacing compound I1 with compound I4 (267 mg, 0.750 mmol) according to the same method as that for preparing compound 6.

[0102] Compound 9 was tested, and the test results were as follows: 1 H NMR (400MHz, CDCl3) δ7.68–7.57(m,4H),7.50–7.41(m,2H),7.41–7.32(m,11H),7 .21(ddt,J=6.8,2.2,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.00(d,J=5 .8Hz,2H),3.90(s,6H),3.68(t,J=6.0Hz,2H),2.72(q,J=5.2Hz,2H),2.60(tt,J= 5.7,4.8Hz,1H),2.30(s,3H),1.65–1.47(m,4H),1.41–1.29(m,4H),1.03(s,9H).

[0103] Comparative Example 1

[0104] Compound 10 is used as a comparative example of a non-silicon-containing hydrophobic tag. Its structure is shown below:

[0105]

[0106] Its synthetic route is as follows:

[0107]

[0108] The structures of the intermediate compound J, compound K, compound L and compound G1 used are shown below:

[0109]

[0110] The specific preparation method is:

[0111] 1) Preparation of compound L:

[0112] At 0°C, compound K (456 mg, 3.00 mmol) was dissolved in tetrahydrofuran (15 mL), and then sodium hydride (180 mg, 4.50 mmol, the content of sodium hydride used was 60%) was added. After stirring at this temperature for ten minutes, compound J (1.45 g, 6.00 mmol) was added, and the reaction was carried out at room temperature overnight. After the reaction was completed, ethyl acetate (40 mL) was added, and the organic phase was washed with saturated brine (20 mL). The organic phase was dried over anhydrous sodium sulfate and concentrated. The crude product was purified by silica gel column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain compound L.

[0113] Compound L was tested, and the test results were as follows: 1H NMR (400MHz, CDCl3) δ3.68 (t, J = 6.8 Hz, 2H), 3.41 (t, J = 6.7 Hz, 2H), 2.32 (dt, J = 10.8, 5.3 Hz, 3H), 2.11 (d, J = 5.1 Hz, 6H), 1.70 (t, J = 5.6 Hz, 6H).

[0114] 2) Preparation of compound 10:

[0115] Compound 10 was obtained by replacing compound C with compound L (62.0 mg, 0.280 mmol) in the same manner as for preparing compound 1.

[0116] Compound 10 was tested, and the test results were as follows: 1 H NMR(400MHz, CDCl3)δ7.57(s,1H),7.46–7.40(m,2H),7.40–7.33(m,5H),7.21 (ddt,J=6.8,2.1,0.9Hz,1H),6.28(s,2H),5.15(d,J=0.9Hz,2H),4.33(t,J=4 .0Hz,2H),4.31–4.24(m,1H),4.14(dd,J=10.4,5.9Hz,4H),3.90(s,6H),3.80 (t,J=4.0Hz,2H),2.30(s,3H),2.11(hept,J=5.5Hz,3H),1.81–1.63(m,12H).

[0117] Compound performance test

[0118] 1) The above-mentioned PD-L1 protein degraders with silicon-containing groups as hydrophobic tags (PD-L1 protein degraders 1-9 prepared in Examples 1-2) and the comparative examples of PD-L1 protein degraders with non-silicon-containing groups as hydrophobic tags (PD-L1 protein degraders 10 prepared in Comparative Example 1) were evaluated for their ability to degrade PD-L1 in the human acute myeloid leukemia cell line kasumi-1 by using protein immunoblotting, and the compound concentrations used were 0.1 μM and 1 μM. The degradation efficiency results are shown in Table 1, and the IC of each compound on kasumi-1 cells was also evaluated. 50 An evaluation was conducted and the results are shown in Table 1.

[0119] Table 1 The degradation efficiency of PD-L1 in human acute myeloid leukemia cell line Kasumi-1 and IC of compounds against human acute myeloid leukemia cell line Kasumi-1 50

[0120]

[0121]

[0122] It can be seen from Table 1 that each compound has a certain ability to degrade PD-L1, and is better than the comparative compound 10 of the PD-L1 protein degrader with a non-silicon-containing group as a hydrophobic tag. Among them, compound 1 has the best effect. Compound 1 was selected for further degradation effect evaluation. The human acute myeloid leukemia cell line kasumi-1 was selected, and eight concentration gradients of 0, 0.15, 0.3, 0.6, 1.25, 2.5, 5, and 10 μM were set to determine whether the compound can degrade PD-L1 in a concentration-dependent manner. The results are shown in Figure 1 The results showed that compound 1 could degrade PD-L1 in human acute myeloid leukemia cell line kasumi-1 in a concentration-dependent manner and degrade DC 50 It is 0.51μM.

[0123] The human acute myeloid leukemia cell line kasumi-1 was selected, and six time gradients of 0, 3, 6, 9, 12, and 24 hours were set to determine whether the compound could degrade PD-L1 in a time-dependent manner. Figure 2 The results showed that compound 1 could time-dependently degrade PD-L1 in the human acute myeloid leukemia cell line kasumi-1.

[0124] 2) The metabolic stability of compound 1 in liver microsomes was evaluated by comparing compound 10 with a non-silicon-containing hydrophobic tag and using Diclofenac as a positive control.

[0125] The specific method for evaluating the metabolic stability of liver microsomes is as follows: take out the liver microsomes from the -80°C refrigerator, place them in a 37°C water bath constant temperature oscillator for pre-incubation for 3 minutes, and melt them for use. Then weigh a certain amount of NADPH, add an appropriate amount of magnesium chloride solution to dissolve it into a 2mM solution for use. According to the composition ratio of the experimental incubation system (3Mm MgCl2-PB solution, 1μM test compound, 0.5mg / mL liver microsomes), prepare the incubation system mixed solution (without NADPH) and distribute it in 40μL / tube. 240 μL of internal standard working precipitant was added to the 0min sample, and then 40 μL of NADPH solution was added (40 μL of magnesium chloride solution was added to the negative control group), and 40 μL of NADPH solution was added to other samples to start the reaction (40 μL of magnesium chloride solution was added to the negative control group), and 240 μL of internal standard precipitant was added after incubation in a 37°C water bath for 5min, 15min, 30min, and 60min, and 40 μL of NADPH solution was added to the positive control group to start the reaction, incubated in a 37°C water bath for 5min, and 240 μL of internal standard precipitant was added after 15min. All samples were vortexed and centrifuged to take 150 μL of supernatant, vortexed and mixed after adding 150 μL of water, and analyzed by LC-MS / MS injection. Through analysis and calculation, it was found that compound 1 showed medium clearance efficiency in two species, such as humans and mice, and was significantly stable in PD-L1 protein degrader comparative example 10 with non-silicon-containing groups as hydrophobic tags, and the results are shown in Table 2.

[0126] Table 2 Metabolic stability of liver microsomes

[0127]

[0128]

[0129] The oral bioavailability of compound 1 was evaluated.

[0130] The specific method for evaluating oral bioavailability is as follows: after fasting overnight, three rats were gavaged and administered (10 mg / kg), and three rats were administered (1 mg / kg) by tail vein. Then, blood was collected at 5min, 15min, 30min, 1h, 2h, 4h, 6h, and 8h, respectively, and placed in a pre-heparinized sodium tube. The blood and sodium heparin were fully mixed by flicking several times, and then centrifuged (4°C, 3000rpm, 10min) to obtain plasma. 50μL of plasma sample was taken, 50μL of diluent (50% methanol / water) and 250μL of methanol precipitant were added, vortexed and centrifuged (4°C, 12000rpm, 10min), and the supernatant was sealed and sent to LC-MS / MS for detection. The results (Table 3) show that compound 1 has a good oral bioavailability of 14.6%.

[0131] Table 3 Kinetic parameters

[0132]

[0133] From Table 2 and the evaluation results of the oral bioavailability experiment, it can be seen that the present invention has made optimizations in terms of the hydrophobic tag type and the linker type, and the selected compound 1 can exert higher metabolic stability and in vivo bioavailability.

[0134] 3) In vivo pharmacodynamic PD experiments were evaluated in a xenograft model, and mice received a single oral dose of compound 1 (10 mg / kg). The mice were euthanized at the specified time points (0 hours, 6 hours, 12 hours, 24 hours, 48 ​​hours, and 72 hours) after oral administration, and tumor tissues were harvested for Western blotting analysis. The data are shown in Table 4, and the results showed that compound 1 significantly reduced PD-L1 expression within 6 hours, and the effect lasted up to 48 hours. These findings indicate that degrader 1 can maintain PD-L1 degradation for a long time in vivo.

[0135] Table 4 PD data

[0136]

[0137] 4) For the in vivo efficacy evaluation of compound 1, a mouse model was established using the human acute myeloid leukemia cell line Kasumi-1 cells.

[0138] Subcutaneous tumor model: The suspension of Kasumi-1 cells was mixed with Matrigel and injected subcutaneously into NU / NU mice. When the average tumor diameter reached 3 mm, they were randomly divided into a control group (5 mice), a compound 1 oral administration group 1 (5 mpk, 5 mice, daily administration), and a compound 1 oral administration group 2 (10 mpk, 5 mice, daily administration). After 18 days, there was no significant fluctuation in the body weight of mice in the administration group and the control group, and there was no obvious abnormality in the state of the mice, indicating that compound 1 was safe. The tumor weight and tumor volume of mice in the administration group were significantly lower than those in the control group. The tumor inhibition rate ((1-tumor weight of the administration group / tumor weight of the control group)*100%) is shown in Table 5. The results showed that compound 1 had a strong in vivo therapeutic effect.

[0139] Table 5 TGI of Kasumi-1 cell xenograft model

[0140]

[0141] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. A PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag, characterized in that: Its structure is shown in Formula I: Wherein, linker is a saturated fatty chain, an unsaturated fatty chain, a linking structure consisting of an aromatic ring and a saturated fatty chain, or a linking structure consisting of an aromatic ring and an unsaturated fatty chain; R is trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, isopropyldimethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, cyclohexyldimethylsilyl, vinyldimethylsilyl, trimethoxysilyl, triethoxysilyl, phenylvinylmethylsilyl or triphenylsilyl.

2. The PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag according to claim 1, characterized in that Its structure is shown in Formula II or Formula III: wherein m and n are independently selected from integers in the range of 1-9.

3. The PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag according to claim 2, characterized in that: Its structure is shown in Formula IV:

4. A method for preparing a PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag as claimed in claim 2, characterized in that: When the structure of the PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag is shown in Formula II, its preparation method is shown in Scheme 1; when the structure of the PD-L1 protein degrader with a silicon-containing group as a hydrophobic tag is shown in Formula III, its preparation method is shown in Scheme 2; Route 1: Route 2:

5. Use of the PD-L1 protein degrader having a silicon-containing group as a hydrophobic tag or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 in the preparation of a drug for treating cancers related to PD-L1 abnormalities.

6. The use according to claim 5, characterized in that: The related cancer is leukemia.

7. A pharmaceutical composition, characterized in that A PD-L1 protein degrader comprising a silicon-containing group as a hydrophobic tag as described in any one of claims 1 to 3, or a pharmaceutically acceptable salt thereof.

8. The pharmaceutical composition according to claim 7, characterized in that Pharmaceutically acceptable excipients are also included.

9. The pharmaceutical composition according to claim 8, characterized in that The excipient is at least one of gum arabic, syrup, lanolin and starch.

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