2,5-diketopiperazine compounds and use thereof

Abstract

Provided in the present invention are 2,5-diketopiperazine compounds and the use thereof. The 2,5-diketopiperazine compounds are a novel series of substituted heterocyclic skeleton compounds. Specifically disclosed is a structural formula shown as formula (I). The 2,5-diketopiperazine compounds have novel structures, good water solubility and antitumor activity, and therefore can be used for preparing pharmaceutical compositions for treating tumors and also can be used as tubulin inhibitors for inhibiting tubulins, achieving wide application scenarios.

Description

A 2,5-diketopiperazine compound and its application Technical Field

[0001] The present invention belongs to the technical field of medicinal chemistry, and specifically relates to a 2,5-diketopiperazine compound and application thereof. Background Art

[0002] Plinabulin (NPI-2358) is a structurally modified derivative of the low-molecular-weight cyclic dipeptide phenylahistin, a metabolite produced by the marine fungus Aspergillus sp. It is a tubulin inhibitor. Plinabulin selectively targets the colchicine binding site on endothelial tubulin, inhibiting tubulin polymerization and blocking microtubule assembly, thereby disrupting the endothelial cytoskeleton and suppressing tumor activity. It also inhibits endothelial cell migration, leading to dysfunction of the tumor vasculature. Experimental studies have shown that Plinabulin arrests cells in early mitosis and induces cell death. Recent studies have shown that Plinabulin is a differentiation-immune and stem cell modulator, as well as a guanine nucleotide exchange factor H1 (GEF-H1) activator, targeting and altering the tumor microenvironment and disrupting tumor vasculature through multiple mechanisms of action. Plinabulin is also a potent antigen-presenting cell (APC) inducer (via dendritic cell maturation), and its sustained anticancer effects are related to its T cell activation.

[0003] The chemical structure of Plinabulin is as follows. Its molecular formula is C 19 H 20 N₄O₂, with a molecular weight of 336.39 and a CAS number of 714272-27-2, has good stability but poor water solubility, making it difficult to commercialize as a drug and a major technical barrier. Existing technologies have modified the structure of Plinabulin, but none of these have addressed its poor water solubility.

[0004] Summary of the Invention

[0005] The present invention provides a 2,5-diketopiperazine compound and its application. The 2,5-diketopiperazine compound has a novel structure, good activity and water solubility, and can overcome the defects of Plinabulin, such as poor water solubility, which is not conducive to drug development and difficult clinical administration.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0007] A 2,5-diketopiperazine compound having the structural formula shown in formula (I):

[0008] Where:

[0009] * is a carbon atom or a chiral carbon atom. When it is a chiral carbon atom, it is an S configuration and / or an R configuration;

[0010] n=0-3; m=0-3; x=0-5;

[0011] R 1 is a mono- or poly-substituted group selected from hydrogen, deuterium, halogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C1-C8 alkyl substituted by one or more halogens, C1-C8 alkoxy, C1-C8 alkoxy substituted by one or more halogens, benzoyl, benzoyl substituted by one or more halogens, phenoxy, phenoxy substituted by one or more halogens, carboxyl, cyano, hydroxyl, nitro and methylthienyl;

[0012] L is "a C1-C8 heteroalkylene group with 1 to 4 heteroatoms selected from one or more of N, O, S and Se", 2 Substituted "heteroatoms selected from one or more of N, O, S and Se, with 1 to 4 heteroatoms of C1-C8 heteroalkylene", C1-C8 alkylene or "substituted by one or more R 2 "substituted C1-C8 alkylene";

[0013] R 2 is C1-C8 alkyl or C3-C 10 Cycloalkyl;

[0014] R 3 、R 4 、R 6 and R 7 is hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, and is surrounded by one or more R 3-1 Substituted C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C1-C8 alkoxy, C3-C 10 Cycloalkyl, C6-C 10 Aryl or "a 3-10 membered heterocycloalkyl group having one or more heteroatoms selected from N, O and S, and 1 to 5 heteroatoms";

[0015] R 3-1 OR 3-1-1 , R 3-1-1 is C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or is replaced by one or more R 3-1-2 Substituted C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl; R 3-1-2 C6-C 10 aryl;

[0016] Z is O, S, SO, SO2 or N(R 5 );

[0017] R 5 is hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, and is surrounded by one or more R 5-1 Substituted C6-C 10 Aryl, benzyl, one or more R 5-2 Substituted benzyl, -C(=O)-R 5-3 or -S(=O)2-R 5-4 ;

[0018] Among them, R 5-1 is a halogen;

[0019] R 5-2 is hydrogen, C1-C8 alkoxy, benzyloxy, one or more R 5-2 Substituted benzyloxy, C1-C8 alkyl, C3-C 10 Cycloalkyl, C2-C8 alkenyl, C6-C 10 Aryl or NR 5-3-1 R 5-3-2 ;

[0020] R 5-3 is C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or C6-C 10 aryl;

[0021] Among them, R 5-3-1 and R 5-3-2 is hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or C3-C 10 Cycloalkyl;

[0022] R 5-4 C1-C8 alkyl or C6-C 10 Aryl.

[0023] Furthermore, in the structural formula:

[0024] n=0-1; m=0-1; x=0-2;

[0025] R 1 is a mono- or poly-substituted group selected from hydrogen, deuterium, vinyl, ethynyl, methyl, trifluoromethoxy, methoxy, halogen, cyano and benzoyl;

[0026] And / or, when L is C1-C8 alkylene, the C1-C8 alkylene is

[0027] and / or, when R 2 When it is a C1-C8 alkyl group, the C1-C8 alkyl group is a methyl group, an ethyl group, an isopropyl group or a tert-butyl group;

[0028] and / or, when R 2 C3-C 10 When cycloalkyl, the C3-C 10 Cycloalkyl is cyclopropyl;

[0029] and / or, when R 3 、R 4 、R 6 and R 7 When it is a C1-C8 alkyl group, the C1-C8 alkyl group is a methyl group or an ethyl group;

[0030] and / or, when R 3 、R 4 、R 6 and R 7 For one or more R 3-1 When the C1-C8 alkyl group is substituted, the 3-1 substituted methyl groups;

[0031] and / or, when R 3 、R 4 、R 6 and R 7 C3-C 10 When cycloalkyl, the C3-C 10 Cycloalkyl is cyclohexyl;

[0032] and / or, when R 3 、R 4 、R 6 and R 7 When it is a “3-10 membered heteroaryl group having 1-5 heteroatoms and one or more heteroatoms selected from N, O and S”, the “3-10 membered heteroaryl group having 1-5 heteroatoms and one or more heteroatoms selected from N, O and S” is pyridyl;

[0033] and / or, when R 3-1-1 When it is a C1-C8 alkyl group, the C1-C8 alkyl group is a methyl group, an ethyl group, an n-propyl group or an n-butyl group;

[0034] and / or, when R 5 When it is a C1-C8 alkyl group, the C1-C8 alkyl group is methyl, ethyl, n-propyl, isopropyl, n-butyl or 2-methylpropyl;

[0035] and / or, when R 5 For one or more R 5-1 Substituted C6-C 10 When the C6-C10 Aryl is phenyl;

[0036] and / or, when R 5-1 When halogen, the halogen is fluorine;

[0037] And / or, the pharmaceutically acceptable salt of the compound represented by formula (I) is a salt prepared from the compound represented by formula (I) and a pharmaceutically acceptable acid, wherein the pharmaceutically acceptable acid is an inorganic acid or an organic acid, the inorganic acid is preferably hydrochloric acid, and the organic acid is preferably methanesulfonic acid.

[0038] Furthermore, in the structural formula:

[0039] for

[0040] and / or

[0041] R 2 isopropyl or cyclopropyl;

[0042] and / or, L is

[0043] and / or, for

[0044] And / or, the pharmaceutically acceptable salt of the compound represented by formula (I) is a salt prepared from the compound represented by formula (I) and a pharmaceutically acceptable acid, wherein the pharmaceutically acceptable acid is hydrochloric acid or methanesulfonic acid;

[0045] And / or, the pharmaceutically acceptable salt of the compound represented by formula (I) is a salt formed by the compound represented by formula (I) and a pharmaceutically acceptable acid in a molar ratio of 1:2.

[0046] Furthermore, the 2,5-diketopiperazine compounds are specifically compounds P-1 to P-33, and their structural formulas are:

[0047] The present invention also provides a pharmaceutical composition containing the 2,5-diketopiperazine compound or its stereoisomers, tautomers, racemates, pharmaceutically acceptable salts, and pharmaceutically acceptable carriers and pharmaceutical excipients.

[0048] Furthermore, the pharmaceutical composition can be administered intravenously, intradermally, intramuscularly, subcutaneously, orally or by inhalation, and the dosage form of the pharmaceutical composition is a gastrointestinal preparation such as tablets, capsules, pills, etc., or a parenteral preparation such as an injection, an external preparation, etc.

[0049] Furthermore, the pharmaceutical composition contains a therapeutically effective amount of a 2,5-diketopiperazine compound or its stereoisomers, tautomers, racemates, pharmaceutically acceptable salts, and a pharmaceutically acceptable carrier, and is used to treat various cancers, infections, inflammations, and conventional proliferative diseases, or to treat other diseases characterized by the appearance of rapidly proliferating cells, such as psoriasis and other skin diseases; wherein the therapeutically effective amount means that the amount of the 2,5-diketopiperazine compound contained in the pharmaceutical composition is sufficient to produce a clinically desired therapeutic effect, such as reducing the tumor size of the user to a clinically acceptable range, or obtaining clinically recognized effectiveness in the treatment of other diseases.

[0050] The present invention also provides use of the 2,5-diketopiperazine compound or the pharmaceutical composition as a tubulin inhibitor for inhibiting tubulin.

[0051] The present invention also provides the use of the 2,5-diketopiperazine compound or the pharmaceutical composition in preparing a drug for treating tumors.

[0052] Further, the tumor includes fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyoma, rhabdomyosarcoma, colon cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, sweat gland cancer, sebaceous gland cancer, papillary carcinoma, papillary adenocarcinoma, cystadenocarcinoma, medullary carcinoma, Bronchogenic carcinoma, renal cell carcinoma, hepatocellular carcinoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, testicular tumors, lung cancer, small cell lung cancer, bladder cancer, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, and retinoblastoma.

[0053] Furthermore, the 2,5-diketopiperazine compound or pharmaceutical composition can also be used to treat conditions such as cancers formed in breast, prostate, kidney, bladder, pancreas or colon tissue; proliferative or neoplastic diseases occurring in adipose tissue, such as adipocyte tumors, i.e., lipoma, fibrolipoma, lipoblastoma, liposis, brown lipoma, hemangioma and / or liposarcoma; and to control infectious agents and parasites (such as bacteria, trypanosomes, fungi, etc.).

[0054] The present invention also provides the use of the 2,5-diketopiperazine compound or the pharmaceutical composition in combination with a chemotherapeutic agent in the preparation of a drug for treating tumors.

[0055] Furthermore, the chemotherapy agent is docetaxel.

[0056] Compared with the existing ones, the advantages and beneficial effects of the present invention are:

[0057] The present invention presents a novel class of 2,5-diketopiperazine compounds, obtained through structural and synthetic route design and chemical synthesis. Compared to the control compound Plinabulin, some compounds exhibit comparable or even superior antitumor activity. Furthermore, some compounds, after salt formation, exhibit excellent water solubility and can be dissolved in a commonly used saline / 5% glucose solution for intravenous administration, demonstrating promising development prospects. DETAILED DESCRIPTION

[0058] The technical solution of the present invention is further described in detail with reference to the following specific examples. In the following examples, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used can be purchased from biological or chemical reagent companies.

[0059] The compounds involved in the following examples are specifically shown below:

[0060] Example 1: Synthesis of Compound P-1

[0061] Step 1:

[0062] To a 50 ml dry round-bottom flask, add (Z)-1-acetyl-3-((5-isopropyl-1H-imidazol-4-yl)methylene)piperazine-2,5-dione 2 (298 mg, 1.08 mmol), 1-chloro-3-morpholinopropane 1 (355 mg, 2.17 mmol), cesium carbonate (708 mg, 2.17 mmol), potassium iodide (180 mg, 1.08 mmol), 4A molecular sieves (500 mg), N,N-dimethylformamide (6 ml) in sequence, vent, protect with nitrogen, place in an oil bath at 70 ° C, and stir to react for 20 h. After the reaction, the reaction solution was transferred to a 100 ml single-necked bottle, washed with ethanol, concentrated under reduced pressure, redissolved with EtOH:DCM = 1:5, filtered, and the filter cake was washed with EtOH:DCM = 1:5 and concentrated under reduced pressure to obtain 348 mg of a brown solid crude product 3 (yield 80.00%). The product was used directly in the next step without purification.

[0063] Step 2:

[0064] A 1L dry, single-necked flask was charged with 3,5-difluorobenzaldehyde 4 (14.2 g, 0.10 mol), 2-(triphenylphosphanylidene)acetaldehyde 5 (33.5 g, 0.11 mmol), and toluene (200 ml). The reaction system was refluxed for 17 hours and then concentrated. The crude product was purified by column chromatography to afford a yellow oil 6 (10.9 g, 65% yield). ESI-MS: m / z = 169 (M+H).

[0065] Step 3:

[0066] To a 25 ml dry brown round-bottom flask, 3 (351 mg, 0.87 mmol), 6 (190 mg, 1.13 mmol), cesium carbonate (425 mg, 1.30 mmol), anhydrous sodium sulfate (247 mg, 1.74 mmol), and N,N-dimethylformamide (6 ml) were added sequentially. The mixture was evacuated, nitrogen atmosphere was maintained, and the mixture was stirred in a 45°C oil bath for 18 h. The reaction was monitored by LC-MS. Upon completion, the reaction solution was transferred to a 100 ml single-necked flask, washed with ethanol, concentrated under reduced pressure, and purified by column chromatography to obtain the desired product P-1 in a yield of 17.52%. ESI-MS: m / z = 512 (M+H).

[0067] The synthesis steps of compounds P-2 to P-4 refer to compound P-1.

[0068] Example 2: Synthesis of Compound P-5

[0069] Step 1, preparation of 3-fluorocinnamaldehyde 8

[0070] 3-Fluorobenzaldehyde 7 (2.00 g, 16.11 mmol) was added to a 250 mL three-necked flask, followed by 70 mL of toluene and (formylmethylene)triphenylphosphine 5 (5.39 g, 17.72 mmol). After addition, the mixture was heated to 120°C and allowed to react for 48 hours before being stopped. The reaction solution was concentrated and sanded, and then column chromatography (PE-PE:EA = 100:1) was performed to obtain 710 mg of the pure product, with a yield of 29%. MS (ESI): m / z 151.1 [M+H] + .

[0071] Step 2: Preparation of compound P-5 (3Z, 6Z)-3-fluorophenylallylidene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione

[0072] A 50 mL dry round-bottom flask was charged with (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (1.59 g, 3.94 mmol), cesium carbonate (1.93 g, 5.91 mmol), sodium sulfate (1.12 g, 7.88 mmol), N,N-dimethylformamide (20 mL), and 3-fluorocinnamaldehyde 8 (0.71 g, 4.73 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 280 mg of the crude product as a yellow solid. Column chromatography yielded 63 mg, a 3.2% yield. MS (ESI): m / z 494.3 [M+H]. + .

[0073] 1 H NMR(600MHz,DMSO-d6)δ11.94(s,1H),10.88(s,1H),7.93(s,1H)7.84-7.80(m,1H),7.54-7.5 0(m,1H),7.42-7.38(m,1H),7.36(d,J=7.7Hz,1H),7.15-7.11(m,1H),6.91(d,J=15.2Hz,1H), 6.71(s,1H),6.53(d,J=12.1Hz,1H),4.05(t,J=7.13Hz,2H),3.57(t,J=4.44Hz,4H),3.27-3.2 1(m,1H),2.39-2.30(m,2H),2.25(t,J=6.7Hz,2H),1.90-1.81(m,2H),1.33(d,J=7.13Hz,6H).

[0074] Step 3, preparation of P-5 hydrochloride:

[0075] Take a 25 mL single-necked dry round-bottom flask and add P-5 (50.0 mg, 0.10 mmol) and methanol (5 mL) in sequence. Add a methanol solution of hydrogen chloride (4 mol / L, 2 mL) dropwise at 0 degrees. Protect from light throughout the process. After the addition, warm to room temperature and react for 2 hours. Concentrate the reaction solution, add a small amount of MeOH to just dissolve the product, and add it dropwise to 10 mL of ethyl acetate. Filter the precipitated solid and take the filter cake to dryness to obtain 48 mg of a light yellow solid.

[0076] 1H NMR(600MHz,DMSO-d6)δ11.86(s,1H),11.32(s,1H),10.89(s,1H),8.03(s,1H),7.81(dd,J=15.2,12.3Hz,1H) ,7.49(d,J=10.7Hz,1H),7.44–7.40(m,1H),7.38(d,J=7.7Hz,1H),7.13-7.10(m,1H),6.91(d,J=15.2Hz,1H), 6.70(s,1H),6.53(d,J=12.2Hz,1H),4.16(t,J=7.2Hz,2H),3.95(d,J=12.5Hz,2H),3.84-3.80(m,2H),3.40-3 .39(m,2H),3.26-3.22(m,1H),3.14-3.10(m,2H),3.09-3.00(m,2H),2.19-2.15(m,2H),1.35(d,J=7.1Hz,6H).

[0077] The synthesis steps of compounds P-6 to P-9 refer to compound P-5.

[0078] Example 3: Synthesis of Compound P-10

[0079] Step 1, preparation of 3-cyanocinnamaldehyde 10:

[0080] 3-Cyanobenzaldehyde 9 (2.00 g, 15.25 mmol) was added to a 250 mL three-necked flask, followed by 70 mL of toluene and (formylmethylene)triphenylphosphine 5 (5.10 g, 16.71 mmol). After addition, the mixture was heated to 120°C and allowed to react for 48 hours before stopping the reaction. The reaction solution was concentrated and sanded, and column chromatography afforded 820 mg of the pure product in a 34% yield. MS (ESI): m / z 158.1 [M+H] + .

[0081] Step 2, preparation of compound P-10 (3Z, 6Z)-3-cyanophenylallylidene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione:

[0082] To a 100 mL dry round-bottom flask were added (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (1.75 g, 4.35 mol), cesium carbonate (2.12 g, 6.52 mmol), sodium sulfate (1.23 g, 8.70 mmol), N,N-dimethylformamide (30 mL), and 3-cyanocinnamaldehyde 10 (0.82 g, 5.22 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 470 mg of the crude product as a yellow solid. Column chromatography yielded 130 mg of the product with an HPLC purity of 99% and a yield of 6.0%. mp = 207-209°C.

[0083] 1 H NMR(600MHz,DMSO-d6)δ11.96(s,1H),10.87(s,1H),7.88(s,1H),7.84-7.74(m,2H),7.57 (d,J=7.0Hz,1H),7.42-7.35(m,2H),6.88(d,J=15.2Hz,1H),6.71(s,1H),6.53(d,J=12.1H z,1H),4.05(t,J=7.1Hz,2H),3.58(t,J=4.3Hz,4H),3.26-3.21(m,1H),2.38-2.30(m,4H) ,2.25(t,J=6.7Hz,2H),1.89-1.80(m,2H),1.34(d,J=7.1Hz,6H).MS(ESI):m / z501.3[M+H] + .

[0084] Step 3, preparation of P-10 hydrochloride:

[0085] Take a 25 mL single-necked dry round-bottom flask and add P-10 (70.0 mg, 0.14 mmol) and methanol (5 mL) in sequence. Add a methanol solution of hydrogen chloride (4 mol / L, 3 mL) dropwise at 0 degrees. Protect from light throughout the process. After the addition, warm to room temperature and react for 2 hours. Concentrate the reaction solution, add a small amount of MeOH to just dissolve the product, and add it dropwise to 10 mL of ethyl acetate to precipitate a solid. Let it stand for 20 minutes and then filter. Take the filter cake and dry it to obtain 71 mg of a light yellow solid.

[0086] 1H NMR (600MHz, DMSO-d6) δ11.85(s,1H),11.18(s,1H),10.91(s,1H),8.02(s,1H),7.81(dd,J=15.5,12.5 Hz,2H),7.57(d,J=6.9Hz,1H),7.41–7.35(m,2H),6.89(d,J=15.2Hz,1H),6.70(s,1H),6.53(d,J=12.2 Hz,1H),4.16(t,J=7.1Hz,2H),3.95(d,J=12.5Hz,2H),3.85–3.77(m,2H),3.45-3.41(m,2H),3.27-3.2 0(m,1H),3.14-3.10(m,2H),3.09-3.01(m,2H),2.19-2.15(m,2H),1.35(d,J=7.1Hz,6H).mp=242-245℃.

[0087] Example 4: Synthesis of Compound P-11

[0088] Step 1, preparation of 3-vinylcinnamaldehyde 12:

[0089] 3-Vinylbenzaldehyde 11 (2.00 g, 15.13 mmol) was added to a 250 mL three-necked flask, followed by 70 mL of toluene and (formylmethylene)triphenylphosphine 5 (5.06 g, 16.64 mmol). The mixture was heated to 120°C and allowed to react for 48 hours before being stopped. The reaction solution was concentrated and sanded, and then column chromatography (PE-PE:EA = 100:1) was performed to obtain 430 mg of the pure product, with a yield of 18%. MS (ESI): m / z 159.1 [M+H] + .

[0090] Step 2, preparation of compound P-11 (3Z, 6Z)-3-vinylphenylallylidene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione:

[0091] A 50 mL dry round-bottom flask was charged with (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (0.92 g, 2.27 mol), cesium carbonate (1.11 g, 3.41 mmol), sodium sulfate (0.64 g, 4.54 mmol), N,N-dimethylformamide (20 ml), and 3-vinylcinnamaldehyde 12 (0.43 g, 2.72 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 220 mg of the crude product as a yellow solid. Column chromatography yielded 22 mg, a 2.0% yield. MS (ESI): m / z 502.3 [M+H]. + .

[0092] Example 5: Synthesis of Compound P-12

[0093] Step 1, preparation of 3-ethynylcinnamaldehyde 14:

[0094] 3-Ethynylbenzaldehyde 13 (2.00 g, 15.37 mmol) was added to a 250 mL three-necked flask, followed by 70 mL of toluene and (formylmethylene)triphenylphosphine 5 (5.15 g, 16.91 mmol). After addition, the mixture was heated to 120°C and allowed to react for 48 hours before being stopped. The reaction solution was concentrated and sanded, and then purified by column chromatography (PE-PE:EA = 100:1) to obtain 560 mg of the pure product, with a yield of 23%. MS (ESI): m / z 157.1 [M+H] + .

[0095] Step 2, preparation of compound P-12 (3Z, 6Z)-3-ethynylphenylallylidene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione:

[0096] A 50 mL dry round-bottom flask was charged with (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (1.20 g, 2.98 mmol), cesium carbonate (1.46 g, 4.47 mmol), sodium sulfate (0.85 g, 5.96 mmol), N,N-dimethylformamide (20 ml), and 3-ethynylcinnamaldehyde 14 (0.56 g, 3.58 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 210 mg of the crude product as a yellow solid. Column chromatography yielded 46 mg, a 3.1% yield. MS (ESI): m / z 500.3 [M+H]. + .

[0097] 1 H NMR(600MHz,DMSO-d6)δ11.97(s,1H),10.90(s,1H),7.90(s,1H),7.85-7.80(m,2H), 7.58(d,J=7.0Hz,1H),7.42-7.37(m,2H),6.90(d,J=15.2Hz,1H),6.71(s,1H),6.53(d ,J=12.1Hz,1H),4.27(s,1H),4.05(t,J=7.1Hz,2H),3.59(t,J=4.2Hz,4H),3.26-3.21 (m,1H),2.34(s,4H),2.26(t,J=6.7Hz,2H),1.88-1.81(m,2H),1.35(d,J=7.1Hz,6H).

[0098] The synthesis steps of compound P-13 refer to compound P-12.

[0099] Example 6: Synthesis of Compound P-14

[0100] Step 1:

[0101] To a 50 ml dry round-bottom flask, 15 (326 mg, 1.08 mmol), 1-chloro-3-morpholinopropane 1 (355 mg, 2.17 mmol), cesium carbonate (708 mg, 2.17 mmol), potassium iodide (180 mg, 1.08 mmol), 4A molecular sieves (500 mg), and DMF (6 ml) were added in sequence. The mixture was evacuated, nitrogen atmosphere was applied, and the mixture was placed in a 70°C oil bath and stirred for 20 h. After completion of the reaction, the reaction solution was transferred to a 100 ml single-necked flask, washed with ethanol, concentrated under reduced pressure, and reconstituted with EtOH:DCM = 1:5. Filtered, the filter cake was washed with EtOH:DCM = 1:5, and concentrated under reduced pressure to obtain 301 mg of crude tan solid 16, with a yield of 65.00%. This was directly used in the next step.

[0102] Step 2:

[0103] To a 25 ml dry brown round-bottom flask, 16 (359 mg, 0.87 mmol), 6 (190 mg, 1.13 mmol), cesium carbonate (425 mg, 1.30 mmol), anhydrous sodium sulfate (247 mg, 1.74 mmol), and N,N-dimethylformamide (6 ml) were added sequentially. The mixture was evacuated, nitrogen atmosphere was maintained, and the mixture was stirred in a 45°C oil bath for 18 h. The reaction was monitored by LC-MS. Upon completion, the reaction solution was transferred to a 100 ml single-necked flask, washed with ethanol, concentrated under reduced pressure, and purified by column chromatography to obtain the desired product P-14 in a 19% yield. ESI-MS: m / z = 538 (M+H).

[0104] The synthesis steps of compounds P-15 to P-25 refer to compound P-14.

[0105] Example 7: Synthesis of Compound P-26

[0106] To a 25 ml dry brown round-bottom flask, 3 (351 mg, 0.87 mmol), 17 (168 mg, 1.13 mmol), cesium carbonate (425 mg, 1.30 mmol), anhydrous sodium sulfate (247 mg, 1.74 mmol), and N,N-dimethylformamide (6 ml) were added sequentially. The mixture was evacuated, nitrogen atmosphere was maintained, and the mixture was stirred in a 45°C oil bath for 18 h. The reaction was monitored by LC-MS. Upon completion, the reaction solution was transferred to a 100 ml single-necked flask, washed with ethanol, concentrated under reduced pressure, and purified by column chromatography to obtain the desired product P-26 in an 18% yield. ESI-MS: m / z = 493 (M+H).

[0107] The synthesis steps of compounds P-27 to P-28 refer to compound P-26.

[0108] Example 8

[0109] Step 1, preparation of compound P-29 (3Z, 6Z)-3-cyanophenylmethylene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione:

[0110] A 50 mL dry round-bottom flask was charged with (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (1.50 g, 3.62 mol), cesium carbonate (1.77 g, 5.43 mmol), sodium sulfate (1.03 g, 7.24 mmol), N,N-dimethylformamide (20 ml), and 3-cyanobenzaldehyde 18 (0.57 g, 4.34 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 690 mg of the crude product as a yellow solid. Column chromatography yielded 240 mg, a 14% yield.

[0111] 1 H NMR(600MHz,DMSO-d6)δ12.07(s,1H),10.56(s,1H),7.99(s,1H),7.92(s,1H),7.79 (d,J=7.9Hz,1H),7.76(d,J=7.7Hz,1H),7.60(t,J=7.8Hz,1H),6.75(d,J=4.0Hz,2H) ,4.07(t,J=7.1Hz,2H),3.60(t,J=4.4Hz,4H),3.27-3.21(m,1H),2.35(s,4H),2.26( t,J=6.7Hz,2H),1.89-1.82(m,2H),1.35(d,J=7.1Hz,6H).mp:237.6-239.6.MW[M+H] + :475.54.

[0112] Step 2, preparation of P-29 hydrochloride:

[0113] Take a 25 mL single-necked dry round-bottom flask and add P-29 (100.0 mg, 0.21 mmol) and methanol (5 mL) in sequence. Add a methanol solution of hydrogen chloride (4 mol / L, 5 mL) dropwise at 0 degrees. Protect from light throughout the process. After the addition, warm to room temperature and react for 2 hours. Concentrate the reaction solution, add a small amount of MeOH to just dissolve the product, and add it dropwise to 10 mL of ethyl acetate to precipitate a solid. Let it stand for 20 minutes and then filter. Take the filter cake and dry it to obtain 101 mg of a light yellow solid.

[0114] 1H NMR(600MHz,DMSO-d6)δ11.90(s,1H),11.56(s,1H),10.60(s,1H),8.11(s,1H),7.98(s,1 H),7.79-7.75(m,2H),7.59(t,J=7.8Hz,1H),6.75(s,1H),6.71(s,1H),4.18(t,J=7.2Hz, 2H),3.98-3.93(m,2H),3.88–3.83(m,2H),3.47–3.36(m,2H),3.27-3.21(m,1H),3.15-3. 11(m,2H),3.07-3.02(m,2H),2.23-2.18(m,2H),1.35(d,J=7.1Hz,6H).mp:268.6-270.6℃.

[0115] Example 9:

[0116] Step 1, preparation of compound P-30 (3Z, 6Z)-3-vinylphenylmethylene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione:

[0117] A 50 mL dry round-bottom flask was charged with (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (1.50 g, 3.62 mol), cesium carbonate (1.77 g, 5.43 mmol), sodium sulfate (1.03 g, 7.24 mmol), N,N-dimethylformamide (20 ml), and 3-vinylbenzaldehyde 11 (0.56 g, 4.34 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 640 mg of the crude product as a yellow solid. Column chromatography yielded 210 mg, a 12% yield.

[0118] 1H NMR(600MHz,DMSO-d6)δ12.00(s,1H),10.27(s,1H),7.89(s,1H),7.59(s,1H),7.45-7.43 (m,2H),7.41-7.37(m,1H),6.80-6.73(m,2H),6.71(s,1H),5.89(d,J=17.6Hz,1H),5.31(d ,J=11.2Hz,1H),4.05(t,J=6.8Hz,2H),3.65-3.52(m,4H),3.27-3.21(m,1H),2.33(s,4H), 2.25(t,J=6.7Hz,2H),1.88-1.80(m,2H),1.34(d,J=7.1Hz,6H).mp:219.0-221.0.MW[M+H] + :476.59.

[0119] Step 2, preparation of P-30 hydrochloride:

[0120] Take a 25 mL single-necked dry round-bottom flask and add P-30 (100.0 mg, 0.21 mmol) and methanol (5 mL) in sequence. Add a methanol solution of hydrogen chloride (4 mol / L, 5 mL) dropwise at 0 degrees. Protect from light throughout the process. After the addition, warm to room temperature and react for 2 hours. Concentrate the reaction solution, add a small amount of MeOH to just dissolve the product, and add it dropwise to 10 mL of EA to precipitate a solid. After standing for 20 minutes, filter and dry the filter cake to obtain 98 mg of a light yellow solid.

[0121] 1 H NMR(600MHz,DMSO-d6)δ11.82(s,1H),11.55(s,1H),10.25(s,1H),8.14(s,1H),7.59(s,1H),7.48–7 .37(m,3H),6.81–6.74(m,2H),6.69(s,1H),5.90(d,J=17.7Hz,1H),5.76(s,1H),5.32(d,J=11.5Hz,1 H),4.18(t,J=7.2Hz,2H),3.96-3.94(m,2H),3.89-3.83(m,2H),3.46-3.37(m,2H),3.27-3.21(m,1H ),3.17-3.09(m,2H),3.09-2.99(m,2H),2.23-2.18(m,2H),1.34(d,J=7.1Hz,6H).mp:260.2-262.2℃.

[0122] Example 10

[0123] Preparation of compound P-31 (3Z, 6Z) -3-ethynylphenylmethylene-6- ((5-isopropyl-1- (-3-morpholinyl) propylimidazol-4-yl) methylene) piperazine-2,5-dione:

[0124] A 50 mL dry round-bottom flask was charged with (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (1.50 g, 3.62 mol), cesium carbonate (1.77 g, 5.43 mmol), sodium sulfate (1.03 g, 7.24 mmol), N,N-dimethylformamide (20 ml), and 3-ethynylbenzaldehyde 13 (0.56 g, 4.34 mmol). The mixture was evacuated and nitrogen atmosphere was applied. The mixture was placed in a 50°C oil bath and protected from light for 24 h. Upon completion of the reaction, the reaction solution was added dropwise to 200 mL of ice water. A yellow solid precipitated and was filtered. The filter cake was drained to give 580 mg of the crude product as a yellow solid. Column chromatography yielded 160 mg, a 9% yield.

[0125] 1H NMR(600MHz,DMSO-d6)δ12.01(s,1H),7.90(s,1H),7.66(s,1H),7.57-7.54(m, 1H),7.46-7.36(m,2H),6.71(d,J=6.4Hz,2H),4.25(s,1H),4.06(t,J=6.8Hz,2 H),3.65-3.52(m,4H),3.27-3.21(m,1H),2.35(s,4H),2.26(t,J=6.7Hz,2H),1 .90-1.82(m,2H),1.35(d,J=7.1Hz,6H).mp:246.5-248.5℃.MW[M+H]+:474.57.

[0126] Example 11

[0127] Step 1, preparation of compound P-32 (3Z, 6Z)-3-fluorophenylmethylene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione:

[0128] Take a 25 ml dry brown round-bottom flask and add (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione 3 (0.73 g, 1.81 mmol), 3-fluorobenzaldehyde 7 (0.22 g, 1.81 mmol), cesium carbonate (0.88 g, 2.71 mmol), anhydrous sodium sulfate (0.51 g, 3.62 mmol), N,N-dimethylformamide (8 ml) in sequence. Exhaust the air, protect with nitrogen, place in a 45 ° C oil bath, and stir to react for 20 hours. The reaction was monitored by LC-MS. After the reaction, the reaction solution was dropped into 4°C cold water (80 ml), filtered with suction, the filter cake was washed with cold water, dried, dissolved in methanol and dichloromethane (1:3), filtered, concentrated under reduced pressure, dried, chromatographed, concentrated under reduced pressure, dried, ultrasonically slurried with methanol, placed in a -30°C refrigerator and allowed to stand, filtered with suction, the filter cake was washed with cold methanol, and dried in vacuo at 50°C to obtain 301.7 mg of the target product in a yield of 35.66%.

[0129] 1 H NMR (600MHz, DMSO-d6) δ12.02(s,1H),10.27(s,1H),7.88(d,J=5.34Hz,1H),7.46-7.40(m,1H),7.3 6(d,J=10.26Hz,1H),7.34(dd,J=9.02,19.44Hz,1H),7.13(td,J=2.37,8.57Hz,1H),6.73(s,1H),6 .71(s,1H),4.04(t,J=7.13Hz,2H),3.57(t,J=4.44Hz,4H),3.24(dt,J=7.10,14.24Hz,1H),2.26(d d,J=24.07,30.84Hz,6H),1.84(p,J=6.86Hz,2H),1.33(d,J=7.13Hz,6H).MS(ESI):m / z468.18[M+H] + .Mp:208-210℃.

[0130] Step 2, preparation of P-32 hydrochloride

[0131] (3Z,6Z)-3-(3-Fluorophenyl)methylene-6-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione, hydrochloride

[0132] To a 100 mL single-necked dry round-bottom flask, (3Z,6Z)-3-(3-fluorophenyl)methylene-6-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione (200.0 mg, 0.43 mmol) and methanol (10 mL) were added sequentially. A methanol solution of hydrogen chloride (4 mol / L, 15 mL) was added dropwise at 0°C in a dark atmosphere. After the addition, the mixture was naturally warmed to room temperature and reacted for 2 h. The reaction solution was concentrated, and a small amount of MeOH was added to just dissolve the product. The mixture was added dropwise to 15 mL of ethyl acetate to precipitate a solid. After stirring for 10 minutes, the mixture was filtered and dried. The filter cake was taken to obtain 218.0 mg of a light yellow solid with a yield of 94%.

[0133] 1H NMR(600MHz,DMSO-d6)δ11.84(s,1H),10.36(s,1H),8.15(s,1H),7.49–7.40(m,1H),7.37( d,J=10.2Hz,1H),7.34(d,J=7.8Hz,1H),7.17-7.14(m,1H),6.75(s,1H),6.69(s,1H),4.19( t,J=7.2Hz,2H),3.96-3.93(m,2H),3.86(t,J=11.5Hz,2H),3.42(d,J=12.2Hz,2H),3.28-3 .21(m,1H),3.14-3.10(m,2H),3.08-3.02(m,2H),2.23-2.18(m,2H),1.34(d,J=7.1Hz,6H).

[0134] Step 3, preparation of P-32 mesylate

[0135] (3Z,6Z)-3-(3-Fluorophenyl)methylene-6-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)methylene)piperazine-2,5-dione, methanesulfonate (P-32-2)

[0136] Take a 100 mL single-necked dry round-bottom flask and add P-32 (200.0 mg, 0.43 mmol), methanol (10 mL), and methanesulfonic acid (102.8 mg, 1.07 mmol) in sequence. Protect from light throughout the process. After the addition, naturally warm to room temperature and react for 2 h. Concentrate the reaction solution, add a small amount of MeOH to just dissolve the product, and add it dropwise to 15 mL of ethyl acetate to precipitate a solid. After stirring for 10 minutes, filter and dry the mixture. Take the filter cake to obtain 268.0 mg of a light yellow solid with a yield of 95%.

[0137] 1H NMR(600MHz,DMSO-d6)δ11.76(s,1H),10.39(s,1H),8.18(s,1H),7.47-7.43(m,1H),7.3 8-7.35(m,1H),7.34(d,J=7.8Hz,1H),7.17-7.14(m,1H),6.76(s,1H),6.68(s,1H),4.16 (t,J=7.3Hz,2H),4.01-3.98(m,2H),3.69(t,J=11.6Hz,2H),3.46(d,J=12.2Hz,2H),3.2 6-3.19(m,3H),3.14-3.06(m,2H),2.42(s,6H),2.16-2.11(m,2H),1.34(d,J=7.1Hz,6H).

[0138] Example 13

[0139] Preparation of compound P-33 (3Z, 6Z)-3-fluorophenylmethylene-6-((5-isopropyl-1-(-3-morpholinyl)propylimidazol-4-yl)allylidene)piperazine-2,5-dione:

[0140] To a 25 mL dry round-bottom flask, (Z)-1-acetyl-3-((5-isopropyl-1-(3-morpholinyl)propylimidazol-4-yl)allylidene)piperazine-2,5-dione 16 (481 mg, 1.12 mmol), cesium carbonate (547 mg, 1.68 mmol), sodium sulfate (318 mg, 2.24 mmol), N,N-dimethylformamide (50 ml), and 3-fluorobenzaldehyde 7 (166 mg, 1.34 mmol) were added in sequence. The mixture was evacuated, nitrogen atmosphere was applied, and the mixture was placed in a 50°C oil bath in the dark for 24 h. The reaction was monitored for completion, and the reaction solution was added dropwise to 50 mL of ice water, filtered, and dried to obtain a yellow solid with a [M+H]+ value of 494.7.

[0141] Example 14: Water solubility test of compounds

[0142] The hydrochloride or methanesulfonate of the compound was dissolved in pure water at 24° C. or 27° C. to obtain the solubility of the compound. The results are shown in Table 1, indicating that the compound has good water solubility after salt formation.

[0143] Table 1: Water solubility test results of compounds

[0144] Example 15 Cell proliferation inhibition test

[0145] Tumor cells (NCI-H460, BxPC-3, HT-29, HepG2) in the logarithmic growth phase were digested and centrifuged. The supernatant was removed and the cells were resuspended in fresh culture medium containing 10% fetal bovine serum. The cells were counted using a cell counter. 100 μL of culture medium (containing cells) was added to a 96-well plate at a standard of 2000-6000 cells per well. The 96-well plate was then filled with PBS on all sides and incubated in an incubator (37°C, 5% CO2) for 24 hours. Once the cells were fully adhered, the test samples and the positive control Plinabulin were diluted to different concentrations in fresh culture medium. A concentration gradient of six different drug concentrations was added, with 100 μL per well and three replicates per concentration. The cells were incubated in a 5% CO2, 37°C incubator for 72 hours. After adding 20 μL of 5 mg / mL MTT to each well and placing it in an incubator for 4 hours, the MTT was discarded and 100 μL of DMSO was added to each well. The plate was placed on a 96-well plate shaker and shaken to completely dissolve the purple formazan. The absorbance (OD value) was then detected at a wavelength of 490 nm using a microplate reader. The experiment also required setting a zeroing well (blank culture medium, MTT, DMSO). Cell inhibition rate = 1-(OD value of the drug-addition group-OD value of the zeroing group) / (OD value of the blank group-OD value of the zeroing group) × 100%. The experimental data were processed using Excel and Origin8.5 software to calculate the IC 50 The experiment was repeated 3 times and the results were averaged.

[0146] Table 2: IC50 of compounds against various cell types

[0147] Among them, NCI-H460 is a human non-small cell lung cancer cell line, BxPC-3 is a human pancreatic cancer cell line, HT-29 is a human colon cancer cell line, and HepG2 is a human liver cancer cell line. Plinabulin is used as a positive control.

[0148] The results are shown in Table 2. The new series of 2,5-diketopiperazine compounds designed and synthesized by the present invention have significant ability to inhibit the growth of tumor cells in H460, BxPC-3, HT-29 and HepG2 cells.

[0149] Especially in the tumor inhibition experiment on liver HepG2 cells, some new series of 2,5-diketopiperazine compounds showed significantly better tumor inhibition activity than the control plinabulin. IC inhibition of HepG2 cell proliferation in vitro by positive drug plinabulin and test substances P-29 hydrochloride, P-30 hydrochloride, P-31 hydrochloride and P-32 hydrochloride 50The results were 289.98±97.65nM, 37.47±1.36nM, 5.70±2.09nM, 12.80±1.67nM, and 4.30±0.49nM, respectively. Furthermore, compounds P-30, P-32, and their hydrochloride salts demonstrated comparable abilities to Plinabulin in inhibiting the growth of other tumor cells. However, the water solubility of the new derivatives was significantly improved after salt formation.

[0150] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A 2,5-diketopiperazine compound, characterized in that: It has a structural formula as shown in formula (I): Where: n=0-3; m=0-3; x=0-5; R 1 is a mono- or poly-substituted group selected from hydrogen, deuterium, halogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C1-C8 alkyl substituted by one or more halogens, C1-C8 alkoxy, C1-C8 alkoxy substituted by one or more halogens, benzoyl, benzoyl substituted by one or more halogens, phenoxy, phenoxy substituted by one or more halogens, carboxyl, cyano, hydroxyl, nitro or methylthienyl; L is C1-C8 heteroalkylene, 2 Substituted C1-C8 heteroalkylene, C1-C8 alkylene or one or more R 2 Substituted C1-C8 alkylene; R 2 is C1-C8 alkyl or C3-C 10 Cycloalkyl; R 3 , R 4 , R 6 and R 7 is hydrogen, deuterium, C1-C8 alkyl, or one or more R 3-1 Substituted C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, C1-C8 alkoxy, C3-C 10 Cycloalkyl, C6-C 10 Aryl or 3-10 membered heterocycloalkyl; wherein R 3-1 OR 3-1-1 , where R 3-1-1 is C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or substituted by one or more C6-C 10 Aryl-substituted C1-C8 alkyl, C1-C8 alkenyl or C1-C8 alkynyl; Z is O, S, SO, SO2 or N(R 5 ); R 5 is hydrogen, deuterium, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl, and is replaced by one or more R 5-1 Substituted C6-C 10 Aryl, benzyl, one or more R 5-2 Substituted benzyl, -C(=O)-R 5-3 or -S(=O)2-R 5-4 ; Among them, R 5-1 is halogen; R 5-2 is hydrogen, C1-C8 alkoxy, benzyloxy, or one or more R 5-2 Substituted benzyloxy, C1-C8 alkyl, C3-C 10 Cycloalkyl, C2-C8 alkenyl, C6-C 10 Aryl or NR 5-3-1 R 5-3-2 ; R 5-3 is C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or C6-C 10 Aryl; wherein R 5-3-1 and R 5-3-2 is hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or C3-C 10 Cycloalkyl; R 5-4 is C1-C8 alkyl or C6-C 10 Aryl.

2. The 2,5-diketopiperazine compound according to claim 1, characterized in that: The heteroatoms in the C1-C8 heteroalkylene of L are selected from one or more of N, O, S and Se, and the number of heteroatoms is 1-4; 3 , R 4 , R 6 and R 7 The heteroatoms in the 3-10 membered heterocycloalkyl are selected from one or more of N, O and S, and the number of heteroatoms is 1-5.

3. The 2,5-diketopiperazine compound according to claim 2, characterized in that: In the structural formula: n=0-1; m=0-1; x=0-2; R 1 is a mono- or poly-substituted group selected from hydrogen, deuterium, vinyl, ethynyl, methyl, trifluoromethoxy, methoxy, halogen, cyano or benzoyl; L is R 2 is methyl, ethyl, isopropyl, tert-butyl or cyclopropyl; R 3 , R 4 , R 6 and R 7 is hydrogen, deuterium, methyl or ethyl, 3-1 substituted methyl, cyclohexyl, or pyridyl; wherein R 3-1 OR 3-1-1 , where R 3-1-1 is methyl, ethyl, n-propyl or n-butyl; Z is O, S, SO, SO2 or N(R 5 ); R 5 is hydrogen, deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl or 2-methylpropyl, C1-C8 alkenyl, C1-C8 alkynyl, and is replaced by one or more R 5-1 Substituted phenyl, benzyl, substituted with one or more R 5-2 Substituted benzyl, -C(=O)-R 5-3 or -S(=O)2-R 5-4 ; Among them, R 5-1 is halogen; R 5-2 is hydrogen, C1-C8 alkoxy, benzyloxy, or one or more R 5-2 Substituted benzyloxy, methyl, ethyl, n-propyl, isopropyl or n-butyl, cyclopentyl or cyclohexyl, C2-C8 alkenyl, C6-C 10 Aryl or NR 5-3-1 R 5-3-2 ; R 5-3 is C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or C6-C 10 Aryl; wherein R 5-3-1 and R 5-3-2 is hydrogen, C1-C8 alkyl, C1-C8 alkenyl, C1-C8 alkynyl or C3-C6 cycloalkyl; R 5-4 is C1-C8 alkyl or C6-C 10 Aryl.

4. The 2,5-diketopiperazine compound according to claim 2, characterized in that: The 2,5-diketopiperazine compounds are specifically compounds P-1 to P-33, and their structural formulas are:

5. A pharmaceutical composition, characterized in that The composition comprises the 2,5-diketopiperazine compound according to claim 1 or its stereoisomer, tautomer, racemate, pharmaceutically acceptable salt, and pharmaceutically acceptable carriers and pharmaceutical excipients.

6. The pharmaceutical composition according to claim 5, characterized in that Its dosage forms include tablets, capsules, pills, injections, and external preparations.

7. Use of the 2,5-diketopiperazine compound according to claim 1 or the pharmaceutical composition according to claim 5 as a tubulin inhibitor for inhibiting tubulin.

8. Use of the 2,5-diketopiperazine compound according to claim 1 or the pharmaceutical composition according to claim 5 in the preparation of a drug for treating tumors.

9. Use of the 2,5-diketopiperazine compound according to claim 1 or the pharmaceutical composition according to claim 5 in combination with a chemotherapeutic agent in the preparation of a drug for treating tumors.

10. The use according to claim 9, characterized in that: The chemotherapeutic agent is docetaxel.

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