A 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative and its applications

Abstract

This invention belongs to the field of pharmaceutical technology, specifically relating to a 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative and its applications. The derivative of this invention is a compound represented by general formula (Ⅰ) and its pharmaceutically acceptable salt, wherein A, X, R1, and R2 are as described in the specification. The compound of this invention exhibits strong ROCK2 inhibitory activity in vitro and can treat ROCK2-related diseases, such as tumors or fibrosis.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to a 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative and its applications. Background Technology

[0002] ROCK, also known as Rho kinase, belongs to the serine / threonine kinase family. When Rho binds to GTP, it activates downstream ROCK, which in turn mediates the phosphorylation of multiple downstream substrates. ROCK participates in cytoskeleton remodeling, cell migration, and stress fiber formation, and is closely related to various physiological functions such as endothelial permeability, tissue contraction, and growth. ROCK has been considered a potential target for various diseases, including eye diseases, cardiovascular diseases, neurological diseases, tumors, and fibrosis.

[0003] In recent years, four ROCK inhibitors have been developed and marketed, mostly for the treatment of eye and cardiovascular diseases. Notably, Belumosudil is currently the only selective ROCK2 inhibitor, approved in 2021 for the treatment of chronic graft-versus-host disease, and its application in pulmonary fibrosis is in phase II clinical trials. However, the presence of 2-phenylquinazoline in its structure results in poor solubility, further limiting its widespread use. Currently, no ROCK inhibitors are approved for the treatment of cancer and fibrosis.

[0004] Imidazolo[1,2-b]pyridazines are a classic class of drug structural fragments. Due to the influence of the polar nitrogen atom in their structure, their derivatives often have better solubility and bioavailability and exhibit broad biological activities in various drugs. For example, the imidazo[1,2-b]pyridazine derivatives disclosed in invention patents CN103360399 and CN112805062 are used as PI3K inhibitors or TRK inhibitors in anti-tumor applications; an imidazo[1,2-b]pyridazine derivative disclosed in invention patent WO2020146194 is used as an IL-17A inhibitor for the treatment of psoriasis, rheumatoid arthritis, and multiple sclerosis; and an imidazo[1,2-b]pyridazine compound disclosed in invention patent WO2024227051 is used as an IRAK inhibitor for the treatment of hematopoietic system cancers, myelodysplastic syndromes, and acute myeloid leukemia. No 3-substituted imidazo[1,2-b]pyridazine-6-amine derivatives have been reported as ROCK inhibitors. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative and its application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative, the derivative being a compound of general formula (I) and its pharmaceutically acceptable salt.

[0008]

[0009] In the formula:

[0010] R1 is hydrogen, an unsubstituted (C1-C6) alkyl group or a (C1-C6) acyl group substituted with at least one identical or different R3;

[0011] R3 is hydroxyl, amino, cyano, carboxyl, (C1-C6)alkoxy, or (C1-C6)alkylamino;

[0012] A is a 5-10 aryl or heteroaryl group, wherein the heteroaryl group contains 1-4 heteroatoms selected from N, O and S;

[0013] X is

[0014] m can be 1, 2, or 3 independently;

[0015] R2 is -NR4R5, -OR4, -SR4,

[0016] R4 and R5 may be the same or different, and are independently selected from hydrogen, unsubstituted or substituted with at least one of the same or different R6 (C1-C6) alkyl, (C3-C6) cycloalkyl, 5-10 aryl or heteroaryl; or R4 and R5 together with the attached nitrogen atom form a 4-8 membered heterocyclic or heteroaryl group, wherein the heterocyclic or heteroaryl group is optionally substituted with 0-3 independent R6 groups;

[0017] R6 is a halogen, hydroxyl, amino, carboxyl, cyano, unsubstituted or substituted with at least one R7 (C1-C6) alkyl, (C3-C6) cycloalkyl, (C6-C7) alkyl group, or cycloalkyl group. 10 aryl, (C1-C6)alkoxy or (C1-C6)alkylamino;

[0018] R7 is a halogen, hydroxyl, amino, cyano, (C1-C6)alkyl, (C1-C6)alkoxy, or (C1-C6)alkylamino.

[0019] Preferably, the derivative is a compound represented by general formula (I) and its pharmaceutically acceptable salt, wherein:

[0020] R1 is hydrogen, an unsubstituted (C1-C6) alkyl group or substituted with at least one identical or different R3;

[0021] R3 is a hydroxyl, amino, cyano, carboxyl, or (C1-C6) alkoxy group;

[0022] A is a 5-8 aryl or heteroaryl group, wherein the heteroaryl group contains 1-4 heteroatoms selected from N, O and S;

[0023] X is

[0024] m can be 1 or 2 independently;

[0025] R2 is -NR4R5, -OR4, -SR4,

[0026] R4 and R5 may be the same or different, and are independently selected from hydrogen, unsubstituted or substituted with at least one of the same or different R6 (C1-C6) alkyl, (C3-C6) cycloalkyl, 5-8 aryl or heteroaryl; or R4 and R5 together with the attached nitrogen atom form a 4-8 membered heterocyclic or heteroaryl group, wherein the heterocyclic or heteroaryl group is optionally substituted with 0-3 independent R6 groups;

[0027] R6 is a halogen, hydroxyl, amino, cyano, unsubstituted or substituted with at least one R7 (C1-C6) alkyl, (C3-C6) cycloalkyl, (C6-C7) alkyl group, or a group that is substituted with at least one R7. 10 aryl, (C1-C6)alkoxy or (C1-C6)alkylamino;

[0028] R7 is a halogen, hydroxyl, amino, cyano, (C1-C6)alkyl, (C1-C6)alkoxy, or (C1-C6)alkylamino.

[0029] More preferably, the derivative is a compound represented by general formula (I) and its pharmaceutically acceptable salt, wherein:

[0030] R1 is hydrogen, an unsubstituted (C1-C3) alkyl group, or an alkyl group substituted with at least one identical or different R3;

[0031] R3 is a hydroxyl, amino, cyano, carboxyl, or (C1-C3) alkoxy group;

[0032] A is a 5-8 aryl or heteroaryl group, wherein the heteroaryl group contains 1-4 heteroatoms selected from N, O and S;

[0033] X is

[0034] m can be 1 or 2 independently;

[0035] R2 is -NR4R5, -OR4, -SR4,

[0036] R4 and R5 may be the same or different, and are independently selected from hydrogen, unsubstituted or substituted with at least one of the same or different R6 (C1-C6) alkyl, (C3-C6) cycloalkyl, 5-8 aryl or heteroaryl; or R4 and R5 together with the attached nitrogen atom form a 4-6 membered heterocyclic group, wherein the heterocyclic group is optionally substituted with 0-2 independent R6s.

[0037] R6 is a halogen, hydroxyl, amino, cyano, unsubstituted or substituted phenyl, (C1-C3) alkyl, (C3-C6) cycloalkyl, (C1-C3) alkoxy or (C1-C3) alkylamino;

[0038] R7 is a halogen, hydroxyl, amino, cyano, (C1-C3) alkyl, or (C1-C3) alkoxy group.

[0039] In a further preferred embodiment, the derivative is a compound represented by general formula (I) and its pharmaceutically acceptable salt, wherein:

[0040] R1 is hydrogen or (C1-C3) alkyl;

[0041] A is a 5-6 aryl or heteroaryl group, wherein the heteroaryl group contains 1-3 heteroatoms optionally selected from N, O and S;

[0042] X is

[0043] R2 is -NR4R5, -OR4, -SR4,

[0044] R3 and R4 may be the same or different, and are independently selected from hydrogen, unsubstituted or substituted with at least one of the same or different R6 (C1-C6) alkyl, (C3-C6) cycloalkyl, phenyl; or R3 and R4 together with the attached nitrogen atom form a 4-6 membered heterocyclic group, wherein the heterocyclic group is optionally substituted with 0-1 independent R6.

[0045] R6 is a halogen, hydroxyl, cyano, unsubstituted or substituted phenyl, (C1-C3) alkyl, (C3-C6) cycloalkyl or (C1-C3) alkoxy;

[0046] R7 is a halogen, (C1-C3) alkyl, or (C1-C3) alkoxy.

[0047] More preferably, the derivative is a compound represented by general formula (I) and its pharmaceutically acceptable salt, wherein:

[0048] R1 is hydrogen, methyl, or isopropyl;

[0049] A is

[0050] X is

[0051] R2 is

[0052] Ideally, the derivative is one of the following compounds and its pharmaceutically acceptable salt.

[0053] N-(1H-indazol-5-yl)-3-[5-(morpholinomethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazine-6-amine;

[0054] N-(1H-indazol-5-yl)-3-[5-(piperidin-1-ylmethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazine-6-amine;

[0055] 1-{{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-1,2,4-oxadiazol-5-yl}methyl}piperidin-4-ol;

[0056] 2-{4-{{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-1,2,4-oxadiazol-5-yl}methyl}piperazin-1-yl}ethane-1-ol;

[0057] 3-{5-[(cyclopropylamino)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0058] 3-{5-[(cyclopentylamino)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0059] 3-{5-{[cyclohexyl(methyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine;

[0060] 3-{5-{[(4-fluorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0061] N-(1H-indazol-5-yl)-3-{5-[(anilino)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine;

[0062] 3-{5-{[(2-chlorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0063] N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine;

[0064] 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0065] 3-{5-{[(3-chloro-4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0066] 3-{5-[(3,5-difluorophenoxy)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine;

[0067] N-(1H-indazol-5-yl)-3-{5-[(2-methoxy-4-methylphenoxy)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine;

[0068] 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)-N-methylimidazo[1,2-b]pyridazine-6-amine;

[0069] 3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-fluorobenzyl)-1,2,4-oxadiazole-5-carboxamide;

[0070] 3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-cyanobenzyl)-1,2,4-oxadiazole-5-carboxamide;

[0071] 3-{6-[(1H-indazol-5-yl)(methyl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-methylbenzyl)-1,2,4-oxadiazole-5-carboxamide;

[0072] N-(1H-indazol-5-yl)-3-{4-[(4-methylpiperidin-1-yl)methyl]thiazo-2-yl}imidazo[1,2-b]pyridazin-6-amine;

[0073] N-(1H-indazol-5-yl)-3-{4-[(4-methylpiperazin-1-yl)methyl]thiazo-2-yl}imidazo[1,2-b]pyridazin-6-amine;

[0074] 3-{4-[(dimethylamino)methyl]thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine;

[0075] 3-{4-[(cyclopentylamino)methyl]thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine;

[0076] 3-{4-{[(cyclopropylmethyl)amino]methyl}thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine;

[0077] 3-{4-{[cyclohexyl(methyl)amino]methyl}thiazo-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine;

[0078] 3-{4-{[(4-fluorophenyl)amino]methyl}thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine;

[0079] N-(1H-indazol-5-yl)-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazo-2-yl}imidazo[1,2-b]pyridazine-6-amine;

[0080] N-(1H-indazol-5-yl)-N-isopropyl-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazo-2-yl}imidazo[1,2-b]pyridazine-6-amine;

[0081] N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(pyrrolidone-1-yl)acetamide;

[0082] N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(isopropylamino)acetamide;

[0083] N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-ylphenyl}-2-(cyclohexyl(ethyl)amino)acetamide.

[0084] The salt of the compound represented by general formula (I) is a pharmaceutically acceptable salt obtained by reacting the compound with an acid, wherein the corresponding acid is hydrochloric acid, hydrobromic acid, sulfuric acid, lactic acid, citric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, tartaric acid, pyruvic acid, acetic acid, maleic acid or succinic acid, fumaric acid, salicylic acid, phenylacetic acid or mandelic acid.

[0085] The use of the 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative of the above, the use of the compound of general formula (I) and its pharmaceutically acceptable salt as a ROCK2 inhibitor.

[0086] The use of the compounds represented by general formula (I) and their pharmaceutically acceptable salts, particularly in the preparation of medicaments for treating tumors or fibrotic diseases.

[0087] The tumors are selected from lung cancer, breast cancer, gastric cancer, colon cancer, hepatocellular carcinoma, oral cancer, kidney cancer, bladder cancer, ovarian cancer, cervical cancer, neuroblastoma, osteosarcoma, and fibrosarcoma; the fibrosis is selected from pulmonary fibrosis, renal fibrosis, liver fibrosis, and myocardial fibrosis.

[0088] Beneficial effects of the present invention

[0089] This invention provides a ROCK2 inhibitor with an imidazo[1,2-b]pyridazine backbone, filling a research gap. It is a 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative formed by replacing the 2-phenylisoquinoline structure of Belumosudil with imidazo[1,2-b]pyridazine via a backbone transition. This improves the physicochemical properties of the molecule and reduces its lipophilicity. This 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative not only exhibits high inhibitory activity against ROCK2 in vitro but also outperforms the marketed ROCK2 inhibitor Belumosudil. In cell experiments, this 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative effectively inhibits the proliferation of MDA-MB-231 breast cancer cells and TGF-β-induced NIH-3T3 mouse embryonic fibroblasts, and also inhibits the migration of MDA-MB-231 cells. Meanwhile, in a bleomycin-induced C57BL / 6 mouse pulmonary fibrosis model, this 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative effectively improved the degree of inflammation in mouse lung tissue, demonstrating therapeutic potential for tumors and fibrotic diseases, and providing a highly promising candidate molecule for the discovery of ROCK2 inhibitors. Attached Figure Description

[0090] Figure 1 The results are from HE & Masson staining experiments on mouse lung tissue. Detailed Implementation

[0091] The present invention will be further described below with reference to specific implementation examples, but the present invention is not limited to these embodiments.

[0092] In the following examples, the proton NMR spectra of the compounds were measured using a Bruker ARX-400 / 600, and the mass spectra were measured using an Agilent 1100 LC / MSD; all reagents used were analytical grade or chemically pure.

[0093] Examples 1-31

[0094]

[0095]

[0096]

[0097] Amine (1);

[0098] The route is shown below:

[0099]

[0100] Step A1: Synthesis of intermediate a1

[0101] 3-Amino-6-pyridazine (10.0 g, 77.5 mmol) was dissolved in DMF (100 mL), and DMF-DMA (18.47 g, 155 mmol) was added. The mixture was stirred at 65 °C for 2 h. The reaction solution was concentrated under reduced pressure, and sodium bicarbonate (9.77 g, 116.25 mmol), potassium iodide (2.57 g, 15.5 mmol), and bromoacetonitrile (18.59 g, 155 mmol) were added. The mixture was stirred at 85 °C for 2 h. After the reaction was complete as detected by TLC, the reaction solution was filtered while hot. The filtrate was added to water (500 mL), stirred, and filtered to obtain a large amount of brown solid, 11.2 g, with a yield of 81.2%.

[0102] Step A2: Synthesis of intermediate a2

[0103] 1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-5-amine (3.6 g, 16.58 mmol) and intermediate a1 (2.46 g, 13.82 mmol) were dissolved in dioxane (20 mL). Pd2(dba)3 (1.27 g, 1.38 mmol), XantPhos (1.60 g, 2.76 mmol), and cesium carbonate (13.51 g, 41.46 mmol) were added. The mixture was stirred at 80 °C for 3 h under nitrogen protection. After the reaction was complete as detected by TLC, the reaction solution was concentrated, tetrahydrofuran (20 mL) was added, and the mixture was stirred and filtered. The filter cake was purified by column chromatography to give 4.2 g of gray solid, with a yield of 85%. Analytical data: ESI-MS [M+H] +(m / z): 360.1.

[0104] Step A3: Synthesis of intermediate a3

[0105] Intermediate a2 (2.0 g, 5.6 mmol) was dissolved in anhydrous ethanol (20 mL), and hydroxylamine hydrochloride (0.58 g, 8.35 mmol) and triethylamine (1.13 g, 11.2 mmol) were added. The mixture was stirred at 80 °C for 3 h. After the reaction was complete as detected by TLC, the reaction solution was evaporated to dryness to give 1.74 g of orange-red solid, with a yield of 79.1%.

[0106] Step A4: Synthesis of intermediate a4

[0107] Intermediate a3 (3.06 g, 7.8 mmol) and triethylamine (0.78 g, 7.8 mmol) were dissolved in DMF (20 mL). Chloroacetyl chloride (0.72 g, 9.36 mmol) was added dropwise under ice bath conditions. After the addition was complete, the mixture was heated to 65 °C and stirred for 2.5 h. After the reaction was complete as detected by TLC, 200 mL of water was added to the reaction solution and stirred. The mixture was extracted three times with ethyl acetate (100 mL each time). The organic phase was evaporated to dryness, and the residue was purified by column chromatography to give 1.51 g of a yellow-green solid, with a yield of 56.0%. Analytical data: ESI-MS [M+H] + (m / z): 451.0; 1 H NMR (400MHz, DMSO-d6) δ9.80(s,1H),9.05(s,1H),8.20(s,1H),8.06(d,J=9.6Hz,1H),7.99(s,1H),7.70(d,J=13.4Hz,2H),7.16(d,J=9.7H z,1H),5.84(d,J=9.5Hz,1H),5.27(s,2H),3.90(s,1H),3.76(s,1H),2.43(d,J=15.2Hz,1H),2.12-1.96(m,2H),1.77(s,1H),1.60(s,2H).

[0108] Step A5: Synthesis of Example 1

[0109] Intermediate a4 (0.2 g, 0.4 mmol) was dissolved in DMF (2 mL), and morpholine (0.05 g, 0.6 mmol) and potassium carbonate (0.11 g, 0.8 mmol) were added. The mixture was stirred at 60 °C for 4 h. After the reaction was complete as detected by TLC, 20 mL of water was added to the reaction solution and stirred, followed by filtration. The filter cake was dissolved in dichloromethane (0.5 mL) and trifluoroacetic acid (0.5 mL) and stirred at room temperature for 3 h. The reaction solution was evaporated to dryness, and water (5 mL) was added and stirred. The solution was adjusted to pH 8 with saturated sodium bicarbonate solution, extracted with dichloromethane (5 mL), and the organic phase was dried over anhydrous sodium sulfate and evaporated to dryness. The crude product was purified by column chromatography to give 79 mg of a pale yellow solid, with a yield of 47.3%. Analytical data: ESI-HRMS [M+Na] + (m / z): 440.1582; 1 HNMR(600MHz,DMSO-d6)δ12.98(s,1H),9.70(s,1H),9.15-9.12(m,1H),8.16(s,1H),8.03(d,J=9.8Hz,1H),7.98( s,1H),7.58-7.51(m,2H),7.13(d,J=9.7Hz,1H),4.06(s,2H),3.63(t,J=4.7Hz,4H),2.61(dd,J=5.6,3.7Hz,4H). 13 C NMR (151MHz, DMSO) δ176.23,160.31,151.83,139.20,136.52,135.07,133.93,133. 53,126.38,123.78,120.34,117.30,115.64,110.71,108.75,66.52,53.14,52.81.

[0110] Example 2: N-(1H-indazol-5-yl)-3-[5-(piperidin-1-ylmethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazin-6-amine (2);

[0111] Following the method in step A5 of Example 1, intermediate a4 was reacted with piperidine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 2, with a yield of 56.8%. Analytical data: ESI-MS [M+H] + (m / z): 416.1; 1HNMR(600MHz,DMSO-d6)δ12.99(s,1H),9.70(s,1H),9.14(s,1H),8.17(s,1H),8.03(d,J=9.7Hz,1H),7.98(s,1H),7. 55(d,J=7.0Hz,2H),7.14(d,J=9.7Hz,1H),4.00(s,2H),2.55(t,J=5.4Hz,4H),1.56-1.53(m,4H),1.40-1.37(m,2H). 13 C NMR (151MHz, DMSO) δ176.65,160.26,151.81,139.17,136.52,135.03,133.94,133.52, 126.36,123.79,120.34,117.34,115.61,110.71,108.75,53.97,53.33,25.90,23.90.

[0112] Example 3: 1-{{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-1,2,4-oxadiazol-5-yl}methyl}piperidin-4-ol (3);

[0113] Following the method in step A5 of Example 1, intermediate a4 was reacted with 4-hydroxypiperidine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 3, with a yield of 40.9%. Analytical data: ESI-HRMS [M+Na] + (m / z): 454.1743; 1 H NMR(600MHz,DMSO-d6)δ13.02(s,1H),9.81(s,1H),9.15(d,J=1.9Hz,1H),8.16(s,1H),8.03(d,J=9.7Hz,1H),7.96(s,1H),7.59-7.51(m,2H) ,4.62(d,J=4.2Hz,1H),4.03(s,2H),3.48(s,2H),2.88-2.80(m,2H),2 .34(s,2H),1.75(dq,J=12.7,3.9Hz,2H),1.46(tt,J=13.2,6.6Hz,2H). 13C NMR(151MHz,DMSO)δ160.28,158.42,151.86,139.22,136.56,135.03,133.97,133.50, 126.34,118.74,117.31,116.75,115.71,110.73,108.70,65.81,52.65,50.95,34.63.

[0114] Example 4: 2-{4-{{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-1,2,4-oxadiazol-5-yl}methyl}piperazin-1-yl}ethane-1-ol (4);

[0115] Following the method in step A5 of Example 1, intermediate a4 was reacted with N-hydroxyethylpiperazine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 4, with a yield of 32.4%. Analytical data: ESI-HRMS [M+Na] + (m / z): 483.2009; 1 H NMR (400MHz, DMSO-d6) δ12.99(s,1H),9.76(d,J=6.1Hz,1H),9.16(q,J=1.9,1.2Hz,1H),8.16(d,J=3.4Hz,1H),8.03(d,J=9.7Hz,1H ),7.97(d,J=3.1Hz,1H),7.60-7.49(m,2H),7.16(dd,J=9.8,2.4Hz,1H),4.11(s,1H),3.59(s,2H),3.35(s,4H),3.02-2.58(m,8H). 13 C NMR(151MHz,DMSO-d6)δ176.16,160.30,151.85,139.22,136.51,135.06,133.96,133.51,1 26.35,123.76,120.35,117.29,115.70,110.72,108.72,59.51,55.59,52.73,52.13,50.84.

[0116] Example 5: 3-{5-[(cyclopropylamino)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (5);

[0117] Following the method in step A5 of Example 1, intermediate a4 was reacted with cyclopropylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 5, with a yield of 49.5%. Analytical data: ESI-MS [M+Na] + (m / z): 410.0; 1 H NMR(600MHz,DMSO-d6)δ13.02(d,J=44.8Hz,1H),9.71(s,1H),9.17(s,1H),8.16(s,1H),8.09-7.94(m,2 H),7.54(s,2H),7.14(d,J=9.4Hz,1H),4.18(s,2H),2.28(s,1H),1.44(s,1H),0.41(s,2H),0.32(s,2H). 13 C NMR(151MHz,DMSO)δ179.03,160.25,151.81,139.14,136.53,134.91,133.96,133 .51,126.37,123.78,120.33,117.45,115.59,110.73,108.74,44.61,30.27,6.70.

[0118] Example 6: 3-{5-[(cyclopentylamino)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (6);

[0119] Following the method in step A5 of Example 1, intermediate a4 was reacted with cyclopentylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 6, with a yield of 47.8%. Analytical data: ESI-HRMS [M+Na] + (m / z): 438.1792; 1 H NMR(600MHz,DMSO-d6)δ12.99(s,1H),9.71(s,1H),9.18(s,1H),8.15(s,1 H),8.03(d,J=9.7Hz,1H),7.98(s,1H),7.54(d,J=2.9Hz,2H),7.14(d,J=9 .7Hz,1H),4.16(s,2H),3.17(p,J=6.2Hz,1H),1.75(dq,J=12.6,6.3Hz,2H ),1.66-1.63(m,2H),1.48(td,J=7.8,7.2,3.6Hz,2H),1.43-1.37(m,3H). 13C NMR(151MHz,DMSO)δ178.75,160.25,151.80,139.15,136.51,134.92,133.95,133.53, 126.36,123.79,120.32,117.41,115.60,110.70,108.75,59.26,43.37,32.62,23.95.

[0120] Example 7: 3-{5-{[cyclohexyl(methyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (7);

[0121] Following the method in step A5 of Example 1, intermediate a4 was reacted with N-methylcyclohexylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 7, with a yield of 50.1%. Analytical data: ESI-HRMS [M+Na] + (m / z): 466.2110; 1 H NMR (600MHz, DMSO-d6) δ12.99(s,1H),9.70(s,1H),9.16(t,J=1.4Hz,1H),8.15(s,1 H),8.03(d,J=9.7Hz,1H),7.97(s,1H),7.58-7.51(m,2H),7.13(d,J=9.8Hz,1H),4.1 0(s,2H),2.47(dd,J=10.4,3.4Hz,1H),2.36(s,3H),1.84(dd,J=9.5,4.8Hz,2H),1. 77-1.72(m,2H),1.57(dt,J=13.0,3.5Hz,1H),1.30-1.17(m,4H),1.14-1.06(m,1H). 13 CNMR(151MHz,DMSO)δ177.98,160.25,151.80,139.15,136.51,134.97,133.95,133.48,126.3 5,123.79,120.33,117.38,115.57,110.70,108.75,62.21,49.05,38.57,29.02,26.13,25.59.

[0122] Example 8: 3-{5-{[(4-fluorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (8);

[0123] Following the method in step A5 of Example 1, intermediate a4 was reacted with 4-fluoroaniline via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 8, with a yield of 59.2%. Analytical data: ESI-HRMS [M+Na] + (m / z): 464.1390; 1 H NMR (600MHz, DMSO-d6) δ12.98(s,1H),9.70(s,1H),9.16(t,J=1.4Hz,1H),8.13(s,1H),8.03(d,J=9.7Hz,1H),7.92(s,1H),7 .60-7.50(m,2H),7.13(d,J=9.8Hz,1H),7.01-6.88(m,2H),6.78-6.71(m,2H),6.52(t,J=6.6Hz,1H),4.79(d,J=6.6Hz,2H). 13 C NMR (151MHz, DMSO) δ160.34,156.18,154.64,151.81,144.76,139.20,136.50,134.99,133.93,133.4 8,126.36,123.77,120.32,117.29,115.99,115.84,115.65,113.87,113.82,110.71,108.76,55.38.

[0124] Example 9: N-(1H-indazol-5-yl)-3-{5-[(anilino)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine (9);

[0125] Following the method in step A5 of Example 1, intermediate a4 was reacted with aniline via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 9, with a yield of 56.4%. Analytical data: ESI-HRMS [M+Na] + (m / z): 446.1483; 1 H NMR (400MHz, DMSO-d6) δ12.97(s,1H),9.69(s,1H),9.15(s,1H),8.14(s,1H),8.03(d,J=9.7Hz,1H),7.92(s,1H), 7.59-7.48(m,2H),7.20-7.04(m,3H),6.74(d,J=8.0Hz,2H),6.59(dt,J=22.0,6.9Hz,2H),4.80(d,J=6.5Hz,2H). 13C NMR (101MHz, DMSO) δ178.44,160.36,151.81,148.10,139.19,136.51,134.99,133.93,13 3.49,129.51,126.36,123.76,120.32,117.48,117.30,115.64,112.90,110.71,108.75.

[0126] Example 10: 3-{5-{[(2-chlorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (10);

[0127] Following the method in step A5 of Example 1, intermediate a4 was reacted with 2-chloroaniline via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 10, with a yield of 44.7%. Analytical data: ESI-HRMS [M+Na] + (m / z): 480.1099; 1 H NMR (400MHz, DMSO-d6) δ12.96 (s, 1H), 9.73 (d, J = 10.9 Hz, 1H), 9.13 (dt, J = 5. 1,1.5Hz,1H),8.12(s,1H),8.03(t,J=9.3Hz,1H),7.90(s,1H),7.60-7.48(m ,2H),7.33(dd,J=7.9,1.5Hz,1H),7.22-7.04(m,2H),6.86(dd,J=8.2,1.4Hz ,1H),6.67(td,J=7.6,1.4Hz,1H),6.41-6.28(m,1H),4.92(d,J=6.5Hz,2H). 13 C NMR (101MHz, DMSO) δ177.99,160.39,151.82,143.77,139.21,136.53,135.01,133.94,133.46,12 9.72,128.53,126.36,123.75,120.33,118.78,118.29,117.25,115.67,112.15,110.73,108.74.

[0128] Example 11: N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine (11);

[0129] Following the method in step A5 of Example 1, intermediate a4 was reacted with 4-methoxybenzylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 11, with a yield of 55.2%. Analytical data: ESI-HRMS [M+Na] + (m / z): 490.1750; 1 H NMR (400MHz, DMSO-d6) δ12.98(s,1H),9.71(s,1H),9.19(t,J=1.4Hz,1H),8.15(s,1H),8.03(d,J=9.8Hz,1H),7.98(s,1H),7.54(d,J= 1.6Hz,2H),7.34-7.27(m,2H),7.14(d,J=9.8Hz,1H),6.93-6.86(m,2H),4.11(s,2H),3.79(s,2H),3.72(s,3H),3.18(d,J=5.0Hz,1H). 13 C NMR (101MHz, DMSO) δ178.67,160.24,158.70,151.80,139.13,136.52,134.92,133.96,133.56,132. 18,129.80,126.35,123.81,120.33,117.47,115.57,114.07,110.70,108.79,55.44,52.05,43.75.

[0130] Example 12: 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (12);

[0131] Following the method in step A5 of Example 1, intermediate a4 was reacted with 4-fluorobenzylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 12, with a yield of 59.3%. Analytical data: 13 C NMR (101MHz, DMSO) δ178.60,162.88,160.25,151.81,139.14,136.55,134.93,133.95,133.55,130.47,1 30.39,129.50,126.36,123.81,120.33,117.45,115.61,115.45,115.24,110.70,108.78,51.82,43.87.

[0132] Example 13: 3-{5-{[(3-chloro-4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (13);

[0133] Following the method in step A5 of Example 1, intermediate a4 was reacted with 4-chloro-3-methoxybenzylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 13, with a yield of 48.5%. Analytical data: ESI-HRMS [M+Na] + (m / z): 524.1357; 1 H NMR (400MHz, DMSO-d6) δ12.97(s,1H),9.71(d,J=7.9Hz,1H),9.18(d,J=4.2 Hz,1H),8.15(s,1H),8.04(dd,J=9.8,3.3Hz,1H),7.97(d,J=4.9Hz,1H),7.5 3(s,2H),7.46(d,J=2.1Hz,1H),7.35-7.27(m,1H),7.17-7.05(m,2H),4.11 (d,J=7.0Hz,2H),3.82(s,3H),3.80(d,J=3.4Hz,2H),3.18(d,J=4.9Hz,1H).

[0134] Example 14: 3-{5-[(3,5-difluorophenoxy)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazine-6-amine (14);

[0135] Following the method in step A5 of Example 1, intermediate a4 was reacted with 3,5-difluorophenol via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 14, with a yield of 59.1%. Analytical data: ESI-HRMS [M+Na] + (m / z): 524.1357; 1 H NMR (400MHz, DMSO-d6) δ12.98(s,1H),9.72(s,1H),9.15(s,1H),8.17(s,1H),8.04(d,J=9.7Hz,1H),7.95 (s,1H),7.54(s,2H),7.15(d,J=9.8Hz,1H),7.03-6.97(m,2H),6.92(tt,J=9.4,2.3Hz,1H),5.75(s,2H). 13C NMR (101MHz, DMSO) δ174.51,164.81,164.65,162.38,162.22,160.54,151.88,139.35,136.52,135.24,133.91 ,133.48,126.38,123.77,120.33,116.96,115.82,110.73,108.76,99.98,99.69,98.22,97.96,97.70,61.98.

[0136] Example 15: N-(1H-indazol-5-yl)-3-{5-[(2-methoxy-4-methylphenoxy)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine (15);

[0137] Following the method in step A5 of Example 1, intermediate a4 was reacted with 3-methoxy-4-methylphenol via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 15, with a yield of 56.2%. Analytical data: ESI-HRMS [M+Na] + (m / z): 491.1591; 1 H NMR (400MHz, DMSO-d6) δ12.98(s,1H),9.73(s,1H),9.14(t,J=1.4Hz,1H),8.18(s,1H),8.04(d,J=9.7Hz,1H),7.95(s,1H),7.53(d,J=1.5Hz, 2H),7.15(d,J=9.8Hz,1H),7.02(d,J=8.1Hz,1H),6.88(d,J=1.9Hz,1H),6.69(dd,J=8.3,1.9Hz,1H),5.54(s,2H),3.80(s,3H),2.26(s,3H). 13 C NMR(151MHz,DMSO-d6)δ175.48,160.47,151.88,149.87,144.95,139.22,136.61,134.98,133.90,133.40,13 2.85,126.31,123.76,121.18,120.33,117.07,116.06,115.88,114.00,110.81,108.75,62.59,56.01,21.14.

[0138] Example 16: 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)-N-methylimidazo[1,2-b]pyridazine-6-amine (16);

[0139] The route is shown below:

[0140]

[0141] Step A6: Preparation of intermediate a5

[0142] Intermediate a2 (2.0 g, 5.6 mmol) was dissolved in DMF (20 mL), and NaH (0.16 g, 6.72 mmol) was added. The mixture was stirred at room temperature for 30 min, followed by the addition of iodomethane (0.87 g, 6.16 mmol). The reaction was stirred at 45 °C for 2 h. After the reaction was complete as monitored by TLC, water (100 mL) was added to the reaction solution, and the mixture was stirred, filtered, and the filter cake was dried to give 1.41 g of a yellow-green solid, with a yield of 67.5%. Analytical data: ESI-MS [M+Na] + (m / z): 396.5.

[0143] Step A7: Preparation of intermediate a6

[0144] According to the method in step A3 of Example 1, intermediate a5 was used as a raw material and reacted with hydroxylamine hydrochloride in a nucleophilic addition reaction to obtain intermediate a6, with a yield of 66.2%.

[0145] Step A8: Preparation of intermediate a7

[0146] According to the method in step A4 of Example 1, intermediate a6 was used as a raw material and cyclized with chloroacetyl chloride to obtain intermediate a7, with a yield of 43.5%.

[0147] Step A9: Preparation of Example 16

[0148] Following the method in step A5 of Example 1, intermediate a7 was reacted with 4-fluorobenzylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 17, with a yield of 42.7%. Analytical data: 1 H NMR (600MHz, DMSO-d6) δ13.26(s,1H),8.12(d,J=5.2Hz,2H),7.84-7.79(m,2H),7.68(d,J=8.7Hz,1H),7.44-7.39(m ,2H),7.36(dd,J=8.7,2.0Hz,1H),7.19-7.10(m,2H),6.60(d,J=10.0Hz,1H),4.07(s,2H),3.83(s,2H),3.51(s,3H). 13C NMR (151MHz, DMSO) δ162.47,160.87,160.17,155.27,139.11,139.02,138.21,136.54,135.37,134.32,130.43, 130.37,129.77,126.26,125.90,124.01,119.26,117.17,115.42,115.28,113.14,112.33,61.97,51.69,43.72.

[0149] Example 17: 3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-fluorobenzyl)-1,2,4-oxadiazole-5-carboxamide (17);

[0150] The route is shown below:

[0151]

[0152] Step A10: Preparation of intermediate a8

[0153] According to the method in step A4 of Example 1, intermediate a3 was used as a raw material and cyclized with oxaloyl chloride monoethyl ester to obtain intermediate a8, with a yield of 41.5%.

[0154] Step A11: Preparation of Example 17

[0155] Intermediate a8 (0.15 g, 0.32 mmol) was dissolved in ethanol (2 mL), and 4-fluorobenzylamine (0.12 g, 0.95 mmol) was added. The mixture was refluxed for 3 h. After the reaction was complete as monitored by TLC, the reaction solution was evaporated to dryness, water (10 mL) was added, and the mixture was stirred and filtered. The filter cake was dissolved in dichloromethane (0.5 mL) and trifluoroacetic acid (0.5 mL), and the mixture was stirred at room temperature for 3 h. The reaction solution was evaporated to dryness, water (5 mL) was added, and the mixture was stirred. The pH of the solution was adjusted to 8 with saturated sodium bicarbonate solution, and the solution was extracted with dichloromethane (5 mL). The organic phase was dried over anhydrous sodium sulfate and evaporated to dryness. The crude product was purified by column chromatography to give 70 mg of a pale yellow solid, with a yield of 41.0%. Analytical data: ESI-HRMS [M+Na] + (m / z): 492.1305. 1H NMR (600MHz, DMSO-d6) δ12.98(s,1H),10.09(t,J=6.2Hz,1H),9.74(s,1H),9.17(t,J=1.4Hz,1H),8.20(s,1H),8.0 5(d,J=9.7Hz,1H),8.01(s,1H),7.53(d,J=1.5Hz,2H),7.51-7.39(m,2H),7.23-7.14(m,3H),4.54(d,J=6.1Hz,2H). 13 C NMR (151MHz, DMSO) δ167.67,161.47,159.87,159.62,152.40,150.75,138.25,134.13,133.61,132.67,1 28.97,128.92,125.22,123.40,122.62,119.14,115.64,114.80,114.49,114.35,109.55,107.65,41.40.

[0156] Example 18: 3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-cyanobenzyl)-1,2,4-oxadiazole-5-carboxamide (18);

[0157] Following the method in step A11 of Example 17, intermediate a8 was reacted with 4-cyanobenzylamine via ammonolysis, followed by deprotection under acidic conditions to obtain Example 18, with a yield of 43.9%. Analysis data: 1 H NMR(600MHz,DMSO-d6)δ12.98(s,1H),10.17(d,J=5.8Hz,1H),9.75(s,1H),9.18(s,1H),8.21(s,1H),8.07-7.99 (m,2H),7.85(d,J=8.0Hz,2H),7.61(d,J=7.9Hz,2H),7.54(s,2H),7.17(d,J=9.8Hz,1H),4.65(d,J=6.1Hz,2H). 13 C NMR (151MHz, DMSO) δ168.72,160.82,153.80,151.94,144.36,139.44,135.30,133.85,132.83,128. 77,126.40,126.16,123.79,120.33,119.32,116.83,116.00,110.74,110.38,108.84,97.63,43.02.

[0158] Example 19: 3-{6-[(1H-indazol-5-yl)(methyl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-methylbenzyl)-1,2,4-oxadiazole-5-carboxamide (19);

[0159] The route is shown below:

[0160]

[0161] Step A12: Preparation of intermediate a9

[0162] According to the method in step A4 of Example 1, intermediate a6 was used as a raw material and cyclized with oxaloyl chloride monoethyl ester to obtain intermediate a9, with a yield of 50.6%.

[0163] Step A13: Preparation of Example 19

[0164] Following the method in step A11 of Example 17, intermediate a9 was reacted with 4-fluorobenzylamine via ammonolysis, followed by deprotection under acidic conditions to obtain Example 19, with a yield of 43.9%. Analytical data: ESI-HRMS [M+Na] + (m / z): 502.1717; 1 H NMR (600MHz, DMSO-d6) δ13.27(s,1H),10.01(t,J=6.2Hz,1H),8.15(d,J=33.1Hz,2H),7.86-7.80(m,2H),7.69(d,J=8.7Hz,1H),7.37(dd, J=8.7,2.0Hz,1H),7.27(d,J=7.7Hz,2H),7.16(d,J=7.7Hz,2H),6.62(d,J=10.0Hz,1H),4.47(d,J=6.2Hz,2H),3.52(s,3H),2.29(s,3H). 13 C NMR (151MHz, DMSO) δ168.71,160.64,155.40,153.45,139.40,139.06,138.11,136.73,135.72,135.56, 134.33,129.39,128.05,126.25,125.94,124.00,119.31,116.56,113.52,112.37,42.99,39.79,21.16.

[0165] Example 20: N-(1H-indazol-5-yl)-3-{4-[(4-methylpiperidin-1-yl)methyl]thiazo-2-yl}imidazo[1,2-b]pyridazin-6-amine (20);

[0166] The route is shown below:

[0167]

[0168] Step A14: Preparation of intermediate a10

[0169] Following the method in step A3 of Example 1, intermediate a2 was reacted with an aqueous solution of ammonium sulfide to obtain intermediate a10, with a yield of 75.1%. Analytical data: ESI-MS [M+H] + (m / z): 394.0;

[0170] Step A15: Preparation of intermediate a11

[0171] Following the method in step A4 of Example 1, intermediate a10 was used as a starting material and underwent a cyclization reaction with 1,3-dichloroacetone to obtain intermediate a11, with a yield of 62.3%. Analytical data: ESI-MS [M+H] + (m / z): 466.0;

[0172] Step A16: Preparation of Example 20

[0173] Following the method in step A5 of Example 1, intermediate a11 was reacted with 4-methylpiperidine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 20, with a yield of 62.5%. Analytical data: ESI-HRMS [M+H] + (m / z): 445.1950; 1 H NMR (600MHz, DMSO-d6) δ13.10 (s, 1H), 9.72 (s, 1H), 8.50 (d, J = 1.9Hz, 1H), 8.16 (d, J=19.0Hz,2H),8.04(d,J=9.7Hz,1H),7.92(s,1H),7.61(d,J=8.8Hz,1H),7.56(dd ,J=8.9,2.0Hz,1H),7.12(d,J=9.7Hz,1H),4.24(s,2H),3.30(s,2H),2.74(s,2H), 1.73(d,J=13.4Hz,2H),1.54(s,1H),1.34(d,J=12.2Hz,2H),0.91(d,J=6.5Hz,3H). 13CNMR(151MHz,DMSO)δ154.66,154.09,152.37,138.24,137.12,133.61,132.94,131.84,126.75 ,124.12,123.40,121.47,116.76,114.97,110.93,110.41,52.73,49.06,32.15,29.01,21.59.

[0174] Example 21: N-(1H-indazol-5-yl)-3-{4-[(4-methylpiperazin-1-yl)methyl]thiazo-2-yl}imidazo[1,2-b]pyridazin-6-amine (21);

[0175] Following the method in step A5 of Example 1, intermediate a11 was reacted with 4-methylpiperazine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 21, with a yield of 66.8%. Analytical data: ESI-HRMS [M+H] + (m / z): 446.1898; 1 H NMR (600MHz, DMSO-d6) δ13.10(s,1H),9.70(s,1H),8.54(d,J=2.0Hz,1H),8.14(d,J=15.0Hz,2H),8.03(d,J=9.7Hz,1H),7. 73(s,1H),7.62-7.53(m,2H),7.11(d,J=9.7Hz,1H),3.80(s,2H),3.10(q,J=7.3Hz,4H),2.78(s,4H),1.19(t,J=7.3Hz,3H). 13 CNMR(151MHz,DMSO)δ153.97,152.80,152.29,138.09,137.09,133.55,133.00,131.60,126 .72,124.36,123.40,121.44,117.31,114.75,110.90,110.35,56.75,53.15,49.77,46.09.

[0176] Example 22: 3-{4-[(dimethylamino)methyl]thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (22);

[0177] Following the method in step A5 of Example 1, intermediate a11 was reacted with dimethylamine hydrochloride via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 22, with a yield of 42.2%. Analytical data: ESI-HRMS [M+H] +(m / z): 391.1477; 1 H NMR (600MHz, DMSO-d6) δ13.05(s,1H),9.62(s,1H),8.54(s,1H),8.15-8.12(m,2H),8.02(d,J=9 .7Hz,1H),7.64(s,1H),7.58(d,J=11.5Hz,2H),7.07(d,J=9.7Hz,1H),3.63(s,2H),2.25(s,6H). 13 C NMR (151MHz, DMSO) δ154.38,153.51,152.22,138.02,137.05,133.62,133.03,131. 54,126.72,124.49,123.43,121.37,116.49,114.60,110.88,110.23,59.16,45.51.

[0178] Example 23: 3-{4-[(cyclopentylamino)methyl]thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (23);

[0179] Following the method in step A5 of Example 1, intermediate a11 was reacted with cyclopentylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 23, with a yield of 51.8%. Analytical data: ESI-HRMS [M+H] + (m / z): 431.1800; 1 H NMR (600MHz, DMSO-d6) δ13.05(s,1H),9.62(s,1H),8.56(d,J=1.9Hz,1H),8.13(d,J=9.5Hz,2H),8.02(d,J=9.6Hz,1H),7.62(s,1H),7.60-7. 52(m,2H),7.07(d,J=9.7Hz,1H),3.89(s,2H),3.11(p,J=6.3Hz,1H),1.76(dq,J=12.5,6.4Hz,2H),1.65(q,J=5.7Hz,2H),1.56-1.34(m,5H). 13 C NMR (151MHz, DMSO) δ156.59,153.62,152.20,138.01,137.05,133.57,133.04,131.55,126 .71,124.49,123.42,121.34,114.79,114.59,110.89,110.20,59.24,48.31,32.88,24.07.

[0180] Example 24: 3-{4-{[(cyclopropylmethyl)amino]methyl}thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (24);

[0181] Following the method in step A5 of Example 1, intermediate a11 was reacted with cyclopropylmethylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 24, with a yield of 46.5%. Analytical data: ESI-HRMS [M+H] + (m / z): 417.1636; 1 H NMR (600MHz, DMSO-d6) δ13.05(s,1H),9.62(s,1H),8.56(d,J=2.2Hz,1H),7.62(d,J=1.0Hz,1H),7.60-7.51(m,2H),7. 07(d,J=9.7Hz,1H),3.94-3.91(m,2H),2.49(d,J=6.7Hz,2H),0.99-0.90(m,1H),0.49-0.37(m,2H),0.18-0.11(m,2H). 13 C NMR(151MHz,DMSO)δ156.67,153.61,152.20,138.01,137.07,133.56,133.04,131.53,126 .71,124.51,123.42,121.34,114.63,114.59,110.91,110.19,54.12,49.41,11.50,3.75.

[0182] Example 25: 3-{4-{[cyclohexyl(methyl)amino]methyl}thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (25);

[0183] Following the method in step A5 of Example 1, intermediate a11 was reacted with N-methylcyclohexylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 25, with a yield of 66.7%. Analytical data: ESI-MS [M+H] + (m / z): 459.3; 1H NMR (600MHz, DMSO-d6) δ13.08(s,1H),9.68(s,1H),8.52-8.49(m,1H),8.15(d,J=12.6H z,2H),8.04(d,J=9.7Hz,1H),7.62-7.53(m,2H),7.11(d,J=9.7Hz,1H),4.27(s,2H),2.8 9(s,1H),2.74(s,1H),2.71-2.53(m,2H),2.03-2.00(m,2H),1.81(d,J=12.8Hz,2H),1.6 1(dt,J=13.0,3.3Hz,1H),1.41(s,2H),1.30-1.21(m,2H),1.12(qt,J=12.9,3.6Hz,1H). 13 C NMR(151MHz,DMSO)δ156.67,153.61,152.20,138.01,137.07,133.56,133.04,131.53,126 .71,124.51,123.42,121.34,114.63,114.59,110.91,110.19,54.12,49.41,11.50,3.75.

[0184] Example 26: 3-{4-{[(4-fluorophenyl)amino]methyl}thiazolyl-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (26);

[0185] Following the method in step A5 of Example 1, intermediate a11 was reacted with 4-fluoroaniline via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 26, with a yield of 72.6%. Analytical data: ESI-HRMS [M+Na] + (m / z): 479.1197; 1 H NMR (400MHz, DMSO-d6) δ13.02(s,1H),9.61(s,1H),8.54-8.49(m,1H),8.16(s,1H),8.12(s,1H),8.02(d,J=9.7H z,1H),7.63-7.51(m,3H),7.07(d,J=9.8Hz,1H),6.98-6.88(m,2H),6.71-6.63(m,2H),6.19(s,1H),4.43(s,2H). 13C NMR(101MHz,DMSO)δ156.05,155.58,154.04,153.75,152.27,145.66,138.07,137.06,133.63,133.00,131.6 0,126.71,124.46,123.42,121.39,115.81,115.59,115.09,114.66,113.58,113.51,110.89,110.27,44.47.

[0186] Example 27: N-(1H-indazol-5-yl)-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazo-2-yl}imidazo[1,2-b]pyridazine-6-amine (27);

[0187] Following the method in step A5 of Example 1, intermediate a11 was reacted with 4-methoxybenzylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 27, with a yield of 63.1%. Analytical data: ESI-HRMS [M+H] + (m / z): 483.1751; 1 H NMR (400MHz, DMSO-d6) δ13.05(s,1H),9.62(s,1H),8.56(s,1H),8.13(d,J=4.9Hz,2H),8.02(d,J=9.7Hz,1H),7.65(s,1H),7.57(q,J= 9.0Hz,2H),7.31(d,J=8.1Hz,2H),7.07(d,J=9.7Hz,1H),6.89(d,J=8.1Hz,2H),6.32-4.76(m,1H),3.88(s,2H),3.74(d,J=2.6Hz,5H). 13 C NMR (101MHz, DMSO) δ158.63,156.18,153.70,152.23,138.03,137.05,133.60,133.05,132.61,131.57, 129.83,126.71,124.50,123.44,121.37,114.93,114.60,114.03,110.88,110.24,55.48,52.24,48.64.

[0188] Example 28: N-(1H-indazol-5-yl)-N-isopropyl-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazo-2-yl}imidazo[1,2-b]pyridazine-6-amine (28);

[0189] The synthesis route is shown below:

[0190]

[0191] Step A17: Preparation of intermediate a12

[0192] According to the method in step A6 of Example 16, intermediate a2 was used as a raw material and reacted with 2-iodopropane in a nucleophilic substitution reaction to obtain intermediate a12, with a yield of 68.7%.

[0193] Step A13: Preparation of intermediate a13

[0194] According to the method in step A3 of Example 1, intermediate a12 was reacted with an aqueous solution of ammonium sulfide to obtain intermediate a10, with a yield of 77.4%.

[0195] Step A14: Preparation of intermediate a14

[0196] According to the method in step A4 of Example 1, intermediate a13 was used as a raw material and cyclized with 1,3-dichloroacetone to obtain intermediate a14, with a yield of 58.4%.

[0197] Step A15: Preparation of Example 28

[0198] Following the method in step A5 of Example 1, intermediate a14 was reacted with 4-methoxybenzylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 28, with a yield of 63.1%. Analytical data: ESI-HRMS [M+Na] + (m / z): 547.2002; 1 H NMR (600MHz, DMSO-d6) δ13.33(s,1H),8.16(d,J=9.0Hz,2H),7.77-7.69(m,3H),7.57(s,1H),7.28(dd,J=36.6,8.4Hz,3H),6.90(d,J=8.1Hz ,2H),6.16(d,J=10.1Hz,1H),5.19-5.16(m,1H),3.88(s,2H),3.75(s,3H),3.45(t,J=5.4Hz,2H),3.33-3.25(m,1H),1.26(d,J=6.5Hz,6H). 13C NMR (151MHz, DMSO) δ158.61,156.22,154.89,154.00,139.59,137.35,134.50,132.70,131.59,131.36,129.81 ,129.66,126.09,124.05,123.97,123.54,114.87,114.02,112.40,112.05,72.97,63.56,55.47,52.24,20.87.

[0199] Example 29: N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(pyrrolidine-1-yl)acetamide (29);

[0200] The synthesis route is shown below:

[0201]

[0202] Step A16: Preparation of intermediate a15

[0203] 3-Amino-6-chloropyridazine (1.0 g, 7.72 mmol) was dissolved in ethanol (10 mL) and water (5 mL), and bromoacetaldehyde diethyl acetal (3.0 g, 15.2 mmol) and hydrobromic acid (0.7 mL) were added. The mixture was refluxed for 8 h. After the reaction was completed as monitored by TLC, the reaction solution was evaporated to dryness, and the residue was added to saturated sodium carbonate solution (10 mL) and stirred. The mixture was then filtered, and the filter cake was washed with water and dried to give 1.05 g of a grayish-white solid, with a yield of 89.1%.

[0204] Step A17: Preparation of intermediate a16

[0205] Intermediate a15 (1.0 g, 6.54 mmol) was dissolved in dichloromethane (10 mL). NBS (1.3 g, 7.19 mmol) was added in portions under ice bath conditions, and the mixture was stirred at room temperature for 4 h. After the reaction was complete as monitored by TLC, the reaction solution was washed twice with saturated sodium bicarbonate solution (10 mL), the organic phase was separated, dried over anhydrous sodium sulfate, and evaporated to dryness to give 1.38 g of a yellow solid, yield 91.4%.

[0206] Step A18: Preparation of intermediate a17

[0207] Intermediate a16 (1.0 g, 4.33 mmol), m-nitrophenylboronic acid (0.87 g, 5.20 mmol), and sodium carbonate (0.69 g, 6.50 mmol) were dissolved in dioxane (10 mL) and water (5 mL). [1,1′-bis(diphenylphosphine)ferrocene]palladium dichloromethane dichloride complex (0.18 g, 0.22 mmol) was added. The mixture was stirred at 80 °C for 4 h under nitrogen protection. After the reaction was complete as monitored by TLC, the reaction solution was evaporated to dryness, and ethyl acetate (20 mL) was added with stirring. The mixture was filtered through diatomaceous earth, and the filtrate was washed twice with saturated sodium chloride solution (20 mL). The organic phase was evaporated to dryness, and the crude product was purified by column chromatography to obtain 0.85 g of a yellow-green solid, with a yield of 71.7%.

[0208] Step A19: Preparation of intermediate a18

[0209] According to the method in step A2 of Example 1, intermediate a18 was obtained by Buchwald-Hartwig coupling reaction of intermediate a17 and 1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-5-amine, with a yield of 36.6%.

[0210] Step A20: Preparation of intermediate a19

[0211] Intermediate a18 (0.15 g, 0.33 mmol) was dissolved in methanol (3 mL), and reduced iron powder (0.15 g, 2.64 mmol) and saturated ammonium chloride aqueous solution (1 mL) were added. The mixture was refluxed for 6 h. After the reaction was completed as monitored by TLC, the reaction solution was filtered while hot, the filtrate was evaporated to dryness, and the residue was added to saturated sodium bicarbonate solution and stirred. The mixture was then filtered, and the crude product was purified by column chromatography to give 0.11 g of a yellow solid, with a yield of 78.6%.

[0212] Step A21: Preparation of intermediate a20

[0213] Intermediate a19 (0.1 g, 0.24 mmol) and triethylamine (0.04 g, 0.36 mmol) were dissolved in tetrahydrofuran (2 mL). Chloroacetyl chloride (0.03 g, 0.28 mmol) was slowly added dropwise at low temperature, and the mixture was stirred at room temperature for 1 h. After the reaction was completed as monitored by TLC, the reaction solution was poured into water (10 mL), stirred, filtered, and the filter cake was dried to give 0.1 g of a yellow solid, with a yield of 83.3%.

[0214] Step A22: Preparation of Example 29

[0215] Following the method in step A5 of Example 1, intermediate a20 was reacted with tetrahydropyrrole via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 29, with a yield of 46.9%. Analytical data: ESI-HRMS [M+H] +(m / z): 453.2176; 1 H NMR (600MHz, DMSO-d6) δ12.98(s,1H),9.88(s,1H),9.49(s,1H),8.47(d,J=2.0H z,1H),8.30(t,J=1.9Hz,1H),7.94(d,J=9.6Hz,2H),7.88(s,1H),7.81(d,J=7.1H z,2H),7.74(dd,J=8.1,2.2Hz,1H),7.55-7.49(m,2H),7.44(dd,J=8.9,2.0Hz,1 H),6.99(d,J=9.7Hz,1H),3.36(s,2H),2.57(d,J=6.1Hz,4H),1.71-1.68(m,4H). 13 C NMR(151MHz,DMSO)δ169.09,151.34,139.37,137.46,136.59,133.88,133.45,130.71,129.91,129.36, 128.11,126.66,123.49,122.55,120.80,119.49,118.62,113.64,110.80,108.69,59.72,54.14,23.86.

[0216] Example 30: N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(isopropylamino)acetamide (30);

[0217] Following the method in step A5 of Example 1, intermediate a20 was reacted with isopropylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 30, with a yield of 38.4%. Analytical data: ESI-HRMS [M+H] + (m / z): 441.2171;

[0218] Example 31: N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-ylphenyl}-2-(cyclohexyl(ethyl)amino)acetamide (31);

[0219] Following the method in step A5 of Example 1, intermediate a20 was reacted with N-ethylcyclohexylamine via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 31, with a yield of 44.7%. Analytical data: ESI-HRMS [M+H] + (m / z): 509.2806; 1H NMR (600MHz, DMSO-d6) δ12.98(s,1H),9.74(s,1H),9.53(s,1H),8.49(d,J=2.0Hz,1H),8.21(d, J=1.9Hz,1H),8.00-7.88(m,1H),7.87-7.82(m,3H),7.81-7.77(m,1H),7.56-7.49(m,2H),7.43 (dd,J=8.9,2.0Hz,1H),7.00(d,J=9.7Hz,1H),3.11(s,2H),2.55(q,J=7.0Hz,2H),2.44(s,1H), 1.78-1.61(m,4H),1.24-1.21(m,2H),1.09(td,J=11.3,10.8,6.0Hz,4H),0.95(t,J=7.1Hz,3H). 13 C NMR (151MHz, DMSO) δ171.33,151.31,138.96,137.43,136.56,133.95,133.37,130.80,130.08,129.48,128.02,126.6 3,123.52,122.62,120.66,119.19,118.31,113.68,110.82,108.42,61.13,54.79,46.52,29.01,26.06,25.86,14.08.

[0220] Example 32: N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)thio]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine;

[0221] Following the method in step A5 of Example 1, intermediate A4 was reacted with 4-methoxybenzyl mercaptan and sodium hydride via a nucleophilic substitution reaction, followed by deprotection under acidic conditions to obtain Example 32, with a yield of 21.9%. Analytical data: ESI-MS [M+H] + (m / z): 485.0; 1H NMR (400MHz, DMSO-d6) δ12.98(s,1H),9.71(d,J=4.6Hz,1H),9.18(d,J=13.2Hz,1H),8.18(d,J=8.3Hz,1H),8.04(d,J=9.8Hz,1H),7.97(d,J= 7.0Hz,1H),7.56-7.51(m,2H),7.37-7.22(m,2H),7.14(d,J=9.8Hz,1H),6.90-6.78(m,2H),4.10(s,2H),3.92(d,J=5.3Hz,2H),3.68(s,3H). 13 C NMR (101MHz, DMSO) δ177.29,160.52,158.86,151.82,139.17,136.50,135.05,133.94,133.52,130. 71,129.39,126.35,123.78,120.34,117.27,115.66,114.36,110.77,108.78,55.42,35.52,24.88.

[0222] Example 33: N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)sulfinyl]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine;

[0223] Example 32 (0.2 g, 0.41 mmol) was dissolved in hexafluoroisopropanol (2 mL), and 30% hydrogen peroxide solution (0.1 mL) was added. The mixture was stirred at room temperature for 2 h. After the reaction was completed as monitored by TLC, the reaction solution was poured into water (10 mL), stirred, filtered, and the filter cake was purified by column chromatography to obtain Example 33 (0.15 g), with a yield of 71.4%. Analytical data: ESI-MS [M+H] + (m / z): 501.0; 1 HNMR (400MHz, DMSO-d6) δ12.98(s,1H),9.71(s,1H),9.18(s,1H),8.16(s,1H),8.03(d,J=9.7Hz,1H),7.97(d,J=6.8Hz,1H),7.5 4(d,J=1.6Hz,2H),7.36-7.25(m,2H),7.14(d,J=9.8Hz,1H),6.91-6.80(m,2H),4.42(s,2H),4.10(d,J=5.0Hz,2H),3.78(s,3H). 13C NMR (101MHz, DMSO) δ178.52,160.47,158.75,151.80,139.16,136.51,134.95,133.92,133.55,131. 48,129.85,126.34,123.77,120.33,117.39,115.48,114.27,110.72,108.79,59.58,55.32,49.56.

[0224] Example 34: N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)sulfonyl]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazine-6-amine;

[0225] Example 32 (0.2 g, 0.41 mmol) was dissolved in glacial acetic acid (2 mL), and 30% hydrogen peroxide solution (1 mL) and sodium tungstate (0.01 g, 0.04 mmol) were added. The mixture was stirred at room temperature for 3 h. After the reaction was completed as monitored by TLC, the reaction solution was poured into water (10 mL), stirred, filtered, and the filter cake was purified by column chromatography to obtain Example 34 (0.16 g), with a yield of 76.2%. Analytical data: ESI-MS [M+H] + (m / z): 517.0; 1 H NMR (400MHz, DMSO-d6) δ12.97(s,1H),9.71(s,1H),9.18(d,J=2.3Hz,1H),8.18(s,1H),8.04(d,J=9.8Hz,1 H),7.97(s,1H),7.53(d,J=1.5Hz,2H),7.38-7.25(m,2H),7.14(d,J=9.8Hz,1H),6.96-6.87(m,2H),4.60(s ,2H),4.35(s,2H),3.81(s,3H).δ178.75,160.38,158.63,151.79,139.15,136.48,134.98,133.97,133.5 7,132.06,130.02,126.34,123.78,120.33,117.47,115.61,114.45,110.70,108.82,58.47,55.29,51.07.

[0226] Example 35: Antitumor and antifibrotic activity experiments were conducted on the compounds prepared in the above examples.

[0227] I. In vitro ROCK2 inhibitory activity

[0228] Using Promega The inhibitory effect of the obtained compounds on ROCK2 was tested using a kinase assay kit. The test compounds were prepared into 10 mM stock solutions using DMSO and serially diluted three-fold with reaction buffer (50 mM HEPES (pH 7.5), 10 mM magnesium chloride hexahydrate, 100 mM sodium orthovanadate, 0.01% CHAPS, and 0.1% bovine serum albumin) to obtain different concentrations of compound solutions. In white flat-bottomed 96-well plates, 20 μL of ROCK2 enzyme solution (1 nM), 10 μL of the compound solution, 10 μL of reaction substrate (20 μM RSK2 peptide KKRNRTLTK), and 10 μL of ATP solution (10 μM) were added to each well sequentially, and the plates were incubated at room temperature for 3 h. The reaction was terminated by adding 50 μL of the assay kit to each well, and the chemiluminescence signal was detected using a Tecan multi-mode microplate reader. All doses were set up in triplicate, and the IC50 was calculated using a GraphPad Prism8 for nonlinear fitting. 50 value.

[0229] The results of the compounds disclosed in this invention inhibiting ROCK2 activity are shown in Table 1. In this table, "++++" indicates IC50. 50 Value < 50 nM; "+++" indicates 50 nM < IC 50 Value < 100nM; "++" indicates 100nM < IC 50 Value < 1 μM; "+" indicates 1 μM < IC 50 Value <10μM.

[0230] Table 1 Results of compounds inhibiting ROCK2 activity

[0231] Example <![CDATA[ROCK2 IC 50 ]]> Example <![CDATA[ROCK2 IC 50 ]]> Example <![CDATA[ROCK2 IC 50 ]]> 1 ++ 13 ++++ 25 +++ 2 ++ 14 +++ 26 +++ 3 ++ 15 +++ 27 ++++ 4 + 16 ++++ 28 ++++ 5 ++ 17 ++++ 29 ++++ 6 ++ 18 ++++ 30 +++ 7 ++ 19 ++++ 31 ++++ 8 +++ 20 ++ 32 ++ 9 +++ 21 ++ 33 + 10 +++ 22 ++ 34 + 11 ++++ 23 +++ Belumosudil ++ 12 ++++ 24 +++

[0232] As can be seen from the above, the compound obtained in this invention exhibits high inhibitory activity against ROCK2, IC50. 50 The values ​​were mostly below 100 nM, which was better than the positive control Belumosudil.

[0233] II. CCK-8 assay for tumor cell and fibroblast toxicity

[0234] The cytotoxicity of some compounds in this invention to human breast cancer cell line MDA-MB-231 and TGF-β-induced mouse embryonic fibroblast NIH / 3T3 cells was detected.

[0235] Cells were cultured in DMEM containing 10% fetal bovine serum in a 37°C incubator containing 5% CO2, with the medium changed every 2–3 days. When cells reached 80%–90% confluence, they were digested with trypsin and collected by centrifugation. The collected cells were resuspended in serum-containing medium and diluted to 2 × 10⁶ cells / mL. 4Cell suspension at a density of 100 μL / well was seeded into 96-well cell culture plates and incubated overnight. The medium was then changed by adding the target compound or solvent (DMSO) at the concentration gradients described above, and incubated for 48 hours. After treatment, the culture medium was discarded, the plates were washed twice with PBS, and 100 μL of CCK-8 working solution was added to each well. The plates were incubated at 37°C in the dark for 1.5 hours, and the OD was measured using a microplate reader. 450 nm The absorbance values ​​of each well were analyzed, and the CC of each compound was calculated. 50 value.

[0236] The results of the anti-proliferative activities of some compounds in this invention against MDA-MB-231 cells and TGF-β-NIH / 3T3 cells are shown in Table 2. In this table, "A" indicates CC. 50 Value < 1 μM; "B" indicates 1 μM < CC 50 Value < 10 μM; "C" indicates 10 μM < C< ... 50 Value <100μM.

[0237] Table 2 shows the anti-proliferation activity of some compounds against MDA-MB-231 and TGF-β-NIH / 3T3 cells.

[0238]

[0239] As can be seen from the above, some of the compounds obtained in this invention have anti-proliferative effects on MDA-MB-231 cells and TGF-β-induced NIH / 3T3 cells. Among them, compounds 11, 12, 13, 16, 17, 18 and 28 have the best anti-proliferative effects on both cell lines, and their CC50 values ​​are all below 1 μM.

[0240] III. In vivo anti-pulmonary fibrosis activity

[0241] Some of the compounds in this invention were tested in an animal model of pulmonary fibrosis in C57BL / 6 mice induced by bleomycin.

[0242] Forty male C57BL / 6 mice (6-8 weeks old, weighing 20-22g) were randomly divided into four groups of ten each. The mice were fasted for 12 hours prior to modeling, but allowed free access to water. All mice were anesthetized by intraperitoneal injection of 0.05 mg / kg of 2% sodium pentobarbital solution. After no response, the mice were suspended vertically with their limbs fixed. A tracheal infusion of 3 U / kg of bleomycin sulfate solution (BLM) was administered via an indwelling needle inserted into the glottis to induce pulmonary fibrosis in each mouse. Seven days after modeling, mice were administered different concentrations of the compound obtained in Example 11 (50 mg / kg or 100 mg / kg) via gavage once daily. Fourteen days after administration, lung tissue was collected for HE & Masson staining to observe alveolar wall thickness, neutrophil infiltration, and collagen fiber area. Lung tissue from healthy C57BL / 6 mice served as a negative control.

[0243] like Figure 1 As shown, after bleomycin induction, the lung tissue of the model group mice exhibited alveolar collapse, alveolar wall thickening, and extensive inflammatory cell infiltration and collagen fiber deposition. After administration of compound 11, the alveolar walls thinned, and collagen fiber deposition was significantly reduced. When the concentration of compound 11 was 100 mg / kg, the lung morphology essentially returned to normal, indicating that compound 11 improved bleomycin-induced pulmonary fibrosis in mice.

Claims

1. A 3-substituted imidazo[1,2- b ] pyridazine-6-amine derivative characterized by: The derivative is a compound represented by general formula (I) and a pharmaceutically acceptable salt thereof, ​ In the formula: R1 is hydrogen, (C1-C6) alkyl; A is , , ; X is , , ; R2is -NR4R5, -OR4, -SR4, or ; R4 and R5 are the same or different, and are independently selected from hydrogen, (C1-C6) alkyl which is unsubstituted or substituted by at least one same or different R6, (C3-C6) cycloalkyl, phenyl; or R4 and R5 together with the nitrogen atom to which they are attached form a 4-6 membered heterocyclyl group which is optionally substituted by 0-1 independent R6; R6 is halogen, hydroxyl, cyano, (C1-C3) alkyl, (C3-C6) cycloalkyl or (C1-C3) alkoxy.

2. A 3-substituted imidazo[1,2- a]pyridazine-6-amine derivative of the formula (I) ###0001### characterized in that b ]pyridazine-6-amine derivative of the formula (I) ###0001### characterized in that The derivative is a compound represented by general formula (I) and a pharmaceutically acceptable salt thereof, in the formula: R1 is hydrogen, (C1-C6) alkyl; A is , , ; X is , , ; R2 is , , , , , , , , , , , , , , , , , , , , , , , , , , .

3. The 3-substituted imidazo[1,2- a]pyridazine-6-amine derivative according to claim 2, characterized in that, b ]pyridazine-6-amine derivative according to claim 1, characterized in that, The derivative is a compound represented by general formula (I) and a pharmaceutically acceptable salt thereof, in the formula: R1 is hydrogen, (C1-C3) alkyl; A is , , ; X is , , ; R2 is , , , , , , , , , , , , , , , , , , , , , , , , , , .

4. The 3-substituted imidazo[1,2- a]pyridazine-6-amine derivative according to claim 3, characterized in that, b ]pyridazine-6-amine derivative according to claim 1, characterized in that, The derivative is a compound represented by general formula (I) and a pharmaceutically acceptable salt thereof, in the formula: R1 is hydrogen, methyl or isopropyl; A is , , ; X is , , ; R2 is , , , , , , , , , , , , , , , , , , , , , , , , , , .

5. The 3-substituted imidazo[l,2- a]pyridazine-6-amine derivative according to claim 4, characterized in that b ]pyridazine-6-amine derivative according to claim 4, characterized in that Specifically selected from the following compounds: N - (1 H - 1,2, 4-oxadiazol-3-yl]imidazo[l,2- b ]pyridazine-6-amine; N - (1 H - (1H-indazol-5-yl)-3-[5-(piperidin-l-ylmethyl)-l,2,4-oxadiazol-3-yl]imidazo[l,2- b ]pyridazine-6-amine; 1 -{3-[6-( 1 -amino- 1 -oxoethyl)- 1 H-indol-3-yl]- 1 H-indol-5 -y l}- 1,2,4-oxadiazol-3- ylmethanol; H - 1 -{3-[6-( 1 -amino- 1 -oxoethyl)- 1 H-indol-3-yl]- 1 H-indol-5 -y l}- 1,2,4-oxadiazol-3- ylmethanol; b - 1 -{3-[6-( 1 -amino- 1 -oxoethyl)- 1 H-indol-3-yl]- 1 2-{4-{{3-{6-[(1 H - indazol-5-yl)amino]imidazo[1,2- b ]pyridazin-3-yl}-1,2,4-oxadiazol-5-yl}methyl}piperazin-1-yl}ethan-1-ol; 3-{5-[(cyclopropylamino)methyl]-1,2,4-oxadiazol-3-yl}- N -1H-indazol-5-yl)imidazo[1,2- H -1H-indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; 3-{5-[(cyclopentylamino)methyl]-l,2,4-oxadiazol-3-yl}-2,6-dinitro-4-trifluoromethylphenyl N - (1 H - indazol-5-yl)imidazo[l,2- b ]pyridazine-6-amine; 3-{5-{[cyclohexyl(methyl)amino]methyl}-1,2,4-oxadiazol-3-yl}- N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; 3-{5-{[(4-fluorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}- N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; N -(1 H -Indazole-5-yl)-3-{5-[(anilino)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2- b ]pyridazine-6-amine; 3-{5-{[(2-chlorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-1,2,4-thiadiazol-5-yl N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; N - (1 H - imidazo[1,2- a]pyrimidin-6-yl)-3-{5-[(4-methoxybenzyl)amino]methyl- 1,2,4- oxadiazol-3-yl}imidazo[1,2-a]pyrimidine; - (1 b ]pyrimidin-6-yl)-3-{5-[(4-methoxybenzyl)amino]methyl- 1,2,4- oxadiazol-3-yl}imidazo[1,2-a]pyrimidine; - (1 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}- N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; 3-{5-{[(3-chloro-4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}- N -(1 H -Indazole-5-yl)imidazo[1,2-b]pyridazine-6-amine; 3-{5-[(3,5-difluorophenoxy)methyl]-1,2,4-oxadiazol-3-yl}-1H-indol-6-ol; N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; N - (1 H - (1H-indazol-5-yl)-3-{5-[(2-methoxy-4-methylphenoxy)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2- b ]pyridazine-6-amine; 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}- N -1 H -indazol-5-yl)- N -1,2,4-oxadiazol-3-yl}-1,2,3,4-tetrahydro-1- b pyrimidin-6-yl)-1,2,3,4-tetrahydro-1 3-{6-[(1 H - (indazol-5-yl) amino] imidazo [1,2- b ] pyridazin-3-yl}- N - (4-fluorobenzyl) -1, 2, 4-oxadiazole-5- carboxamide; 3-{6-[(1 H - (indazol-5-yl) amino] imidazo [1,2- b ] pyridazin-3-yl}- N - (4-cyanobenzyl) -1, 2, 4-oxadiazole-5-carboxamide; 3-{6-[(1 H - indazol-5-yl)(methyl)amino]imidazo[1,2- b ]pyridazin-3-yl}- N - (4-methylbenzyl)-1,2,4-oxadiazole-5-carboxamide; N - (1 H - (1H-indazol-5-yl)-3-{4-[(4-methylpiperidin-1-yl)methyl]thiazol-2-yl}imidazo[1,2- b ]pyridazine-6-amine; N - (1 H - (1H-indazol-5-yl)-3-{4-[(4-methylpiperazin-1-yl)methyl]thiazol-2-yl}imidazo[1,2- b ]pyridazine-6-amine; 3-{4-[(dimethylamino)methyl]thiazol-2-yl}- N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; 3-{4-[(cyclopentylamino)methyl]thiazol-2-yl}- N -1 H -indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; 3-{4-{[(cyclopropylmethyl)amino]methyl}thiazol-2-yl}- N - (1 H - indazol-5-yl)imidazo[l,2- b ]pyridazine-6-amine; 3-{4-{[cyclohexyl(methyl)amino]methyl}thiazol-2-yl}- N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; 3-{4-{[(4-fluorophenyl)amino]methyl}thiazol-2-yl}- N - (1 H - indazol-5-yl)imidazo[1,2- b ]pyridazine-6-amine; N - (1 H - (1H-indazol-5-yl)-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazol-2-yl}imidazo[1,2- b ]pyridazine-6-amine; N - (1 H - indazol-5-yl)- N - isopropyl-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazol-2-yl}imidazo[1,2- b ]pyridazine-6-amine; N - {3 - [6- [( 1 H - [ 1,2,4] triazol- 1 -yl]imidazo [ 1,2- b ]pyridazin-3-yl}phenyl}-2-(pyrrolidin- 1 -yl)acetamide; N - {3 - [6- [( 1 H - [ 1,2,4] triazol- 1 -yl]imidazo [ 1,2- b ]pyridazin-3-yl}phenyl}-2-(isopropylamino)acetamide; N - {3 - [6- [( 1 H - [ 1,2,4] triazol- 1 -yl]imidazo [ 1,2- b ]pyridazin-3-ylphenyl}-2-(cyclohexyl(ethyl)amino)acetamide; N - (1 H - (1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)thio]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2- b ]pyridazine-6-amine; N -(1 H -Indazole-5-yl)-3-{5-{[(4-methoxybenzyl)sulfinyl]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2- b ]pyridazine-6-amine; N -(1 H -Indazole-5-yl)-3-{5-{[(4-methoxybenzyl)sulfonyl]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2- b ]pyridazine-6-amine.

6. The 3-substituted imidazo[1,2- a]pyridazine-6-amine derivatives according to any one of claims 1 to 5, characterized by: b ]pyridazine-6-amine derivatives, characterized by: The salt of the compound represented by general formula (I) is a pharmaceutically acceptable salt obtained by reacting the compound with an acid, and the corresponding acid is hydrochloric acid, hydrobromic acid, sulfuric acid, lactic acid, citric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, tartaric acid, pyruvic acid, acetic acid, maleic acid, succinic acid, fumaric acid, salicylic acid, phenylacetic acid or mandelic acid.

7. Use of a 3-substituted imidazo[l,2- a]pyridazine-6-amine derivative according to claim 1, characterized in that: b ] pyridazine-6-amine derivative according to claim 1, characterized in that: The compound represented by general formula (I) and the pharmaceutically acceptable salt thereof are used for preparing a ROCK2 inhibitor.

8. Use of a 3-substituted imidazo[1,2- b ]pyridazine-6-amine derivative according to claim 7, characterized in that: The compound represented by general formula (I) and the pharmaceutically acceptable salt thereof are used for preparing a drug for treating a tumor or a fibrosis disease.

9. Use according to claim 8, characterized in that, The tumor is selected from lung cancer, breast cancer, gastric cancer, colon cancer, hepatocellular carcinoma, oral cancer, renal cancer, bladder cancer, ovarian cancer, cervical cancer, neuroblastoma, osteosarcoma, fibrosarcoma; the fibrosis is selected from pulmonary fibrosis, renal fibrosis, liver fibrosis, myocardial fibrosis.

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