3-substituted imidazo [1, 2-b] pyridazine-6-amine derivative and application thereof

Abstract

The invention belongs to the technical field of medicines, and particularly relates to a 3-substituted imidazo [1, 2-b] pyridazine-6-amine derivative and application thereof. The derivative is a compound as shown in a general formula (I) and pharmaceutically acceptable salts thereof, and A, X, R1 and R2 are described in the specification. The compound disclosed by the invention has relatively strong ROCK2 inhibitory activity in vitro, and can be used for treating ROCK2 related diseases, such as tumors or fibrosis and the like. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical technology, and particularly relates to a 3-substituted imidazo[1,2-b]pyridazin-6-amine derivative and its application. Background Art

[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, participates in cytoskeleton reorganization, cell migration, and the formation of stress fibers, 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 such as eye diseases, cardiovascular diseases, nervous system diseases, tumors, and fibrosis.

[0003] In recent years, four ROCK inhibitors have been developed and marketed, and most of them are used for the treatment of eye diseases and cardiovascular diseases. It is worth mentioning that Belumosudil is currently the only selective ROCK2 inhibitor, which was approved for the treatment of chronic graft-versus-host disease in 2021, and its treatment of pulmonary fibrosis is also in clinical phase II trials. However, due to the influence of 2-phenylquinazoline in its structure, Belumosudil has poor solubility, which further limits its wide application. Currently, no ROCK inhibitor has been approved for the treatment of tumors and fibrosis.

[0004] Imidazo[1,2-b]pyridazine is a class of classic drug structure fragments. Due to the influence of polar nitrogen atoms in its structure, its 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; a class of imidazo[1,2-b]pyridazine derivatives as IL-17A inhibitors disclosed in invention patent WO2020146194 are used 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 hematological cancers, myelodysplastic syndromes, and acute myeloid leukemia, etc. Currently, 3-substituted imidazo[1,2-b]pyridazin-6-amine derivatives have not been reported as ROCK inhibitors. Summary of the Invention

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

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A 3-substituted imidazo[1,2-b]pyridazin-6-amine derivative, the derivative being a compound represented by the general formula (I) and a pharmaceutically acceptable salt thereof,

[0008]

[0009] In the formula:

[0010] R 1 is hydrogen, unsubstituted or substituted by at least one identical or different R 3 substituted (C 1 -C 6 ) alkyl and (C 1 -C 6 ) acyl;

[0011] R 3 is hydroxyl, amino, cyano, carboxyl, (C 1 ~C 6 ) alkoxy or (C 1 ~C 6 ) alkylamino;

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

[0013] X is

[0014] m is independently 1, 2, or 3;

[0015] R 2 is -NR 4 R 5 、-OR 4 、-SR 4 、

[0016] R 4 and R 5 are the same or different and are each independently selected from hydrogen, unsubstituted or substituted by at least one identical or different R 6 substituted (C 1 -C 6 ) alkyl, (C 3 -C 6 ) cycloalkyl, 5- to 10-membered aryl or heteroaryl; or R 4 and R 5 together with the nitrogen atom to which they are attached form a 4- to 8-membered heterocyclic group or heteroaryl group, and the heterocyclic group or heteroaryl group is optionally substituted by 0 to 3 independent R 6 substituents;

[0017] R6 is halogen, hydroxyl, amino, carboxyl, cyano, unsubstituted or substituted by at least one R 7 substituted (C 1 ~C 6 ) alkyl, (C 3 -C 6 ) cycloalkyl, (C 6 ~C 10 ) aryl, (C 1 ~C 6 ) alkoxy or (C 1 ~C 6 ) alkylamino;

[0018] R 7 is halogen, hydroxyl, amino, cyano, (C 1 ~C 6 ) alkyl, (C 1 ~C 6 ) alkoxy or (C 1 ~C 6 ) alkylamino.

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

[0020] R 1 is hydrogen, unsubstituted or substituted by at least one identical or different R 3 substituted (C 1 -C 6 ) alkyl;

[0021] R 3 is hydroxyl, amino, cyano, carboxyl, or (C 1 ~C 6 ) alkoxy;

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

[0023] X is

[0024] m is independently 1 or 2;

[0025] R 2 is -NR 4 R 5 、-OR 4 、-SR 4 、

[0026] R 4 and R 5 are the same or different and are each independently selected from hydrogen, unsubstituted or substituted by at least one identical or different R 6Substituted (C 1 -C 6 ) alkyl, (C 3 -C 6 ) cycloalkyl, 5- to 8-membered aryl or heteroaryl; or R 4 and R 5 together with the attached nitrogen atom form a 4- to 8-membered heterocyclic group or heteroaryl, which is optionally substituted with 0 to 3 independent R 6 substituents;

[0027] R 6 is halogen, hydroxy, amino, cyano, unsubstituted or substituted with at least one R 7 substituted (C 1 -C 6 ) alkyl, (C 3 -C 6 ) cycloalkyl, (C 6 -C 10 ) aryl, (C 1 -C 6 ) alkoxy or (C 1 -C 6 ) alkylamino;

[0028] R 7 is halogen, hydroxy, amino, cyano, (C 1 -C 6 ) alkyl, (C 1 -C 6 ) alkoxy or (C 1 -C 6 ) alkylamino.

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

[0030] R 1 is hydrogen, unsubstituted or substituted with at least one identical or different R 3 substituted (C 1 -C 3 ) alkyl;

[0031] R 3 is hydroxy, amino, cyano, carboxy, or (C 1 -C 3 ) alkoxy;

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

[0033] X is

[0034] m is independently 1 or 2;

[0035] R 2 is -NR 4 R 5 、 -OR 4 、 -SR 4 、

[0036] R 4 and R 5 are the same or different and are each independently selected from hydrogen, unsubstituted or substituted by at least one identical or different R 6 (C 1 -C 6 )alkyl, (C 3 -C 6 )cycloalkyl, a 5 - 8 - membered aryl or heteroaryl; or R 4 and R 5 together with the nitrogen atom to which they are attached form a 4 - 6 - membered heterocyclic group, which heterocyclic group is optionally substituted by 0 - 2 independent R 6 substituents;

[0037] R 6 is halogen, hydroxy, amino, cyano, unsubstituted or substituted by at least one R 7 phenyl, (C 1 ~C 3 )alkyl, (C 3 -C 6 )cycloalkyl, (C 1 ~C 3 )alkoxy or (C 1 ~C 3 )alkylamino;

[0038] R 7 is halogen, hydroxy, amino, cyano, (C 1 ~C 3 )alkyl or (C 1 ~C 3 )alkoxy.

[0039] More preferably, the derivative is a compound of the general formula (I) and its pharmaceutically acceptable salts, wherein:

[0040] R 1 is hydrogen, (C 1 -C 3 )alkyl;

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

[0042] X is

[0043] R 2-NR 4 R 5 、 -OR 4 、 -SR 4 、

[0044] R 3 and R 4 are the same or different and are each independently selected from hydrogen, unsubstituted or substituted by at least one identical or different R 6 (C 1 -C 6 )alkyl, (C 3 -C 6 )cycloalkyl, phenyl; or R 3 and R 4 together with the nitrogen atom to which they are attached form a 4- to 6-membered heterocyclic group, which heterocyclic group is optionally substituted by 0-1 independent R 6 ;

[0045] R 6 is halogen, hydroxy, cyano, unsubstituted or substituted by at least one R 7 phenyl, (C 1 ~C 3 )alkyl, (C 3 -C 6 )cycloalkyl or (C 1 ~C 3 )alkoxy;

[0046] R 7 is halogen, (C 1 ~C 3 )alkyl or (C 1 ~C 3 )alkoxy.

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

[0048] R 1 is hydrogen, methyl or isopropyl;

[0049] A is

[0050] X is

[0051] R 2 is

[0052] Most preferably, the derivative is the following compound and a pharmaceutically acceptable salt thereof,

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

[0054] N-(1H-Indazol-5-yl)-3-[5-(piperidin-1-ylmethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazin-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}ethan-1-ol;

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

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

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

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

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

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

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

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

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

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

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

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

[0078] 3-{4-{[(4-Fluorophenyl)amino]methyl}thiazol-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}thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine;

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

[0081] N-{3-{6-[(1H-Indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(pyrrolidin-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 the general formula (I) is a pharmaceutically acceptable salt obtained by reacting the compound with an acid, and the corresponding acids are 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] Use of a 3-substituted imidazo[1,2-b]pyridazin-6-amine derivative as described above, use of the compound represented by the general formula (I) and its pharmaceutically acceptable salts as ROCK2 inhibitors.

[0086] Use of the compound represented by the general formula (I) and its pharmaceutically acceptable salts in the preparation of a medicament for treating tumors or fibrotic diseases, in particular.

[0087] The tumors mentioned above 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, fibrosarcoma; the fibrosis is selected from pulmonary fibrosis, renal fibrosis, hepatic fibrosis, myocardial fibrosis.

[0088] Advantages of the present invention

[0089] The present invention provides a ROCK2 inhibitor with an imidazo[1,2-b]pyridazine backbone, filling the research gap; it is a 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative formed by replacing the 2-phenylisoquinoline structure of Belumosudil through skeletal jump, which helps to improve the physicochemical properties of the molecule and reduce lipophilicity. This 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative not only shows high inhibitory activity against ROCK2 in vitro, but also is superior to the marketed ROCK2 inhibitor Belumosudil. In cell experiments, this 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative can effectively inhibit the proliferation of MDA-MB-231 breast cancer cells and TGF-β-induced NIH-3T3 mouse embryonic fibroblasts and inhibit the migration of MDA-MB-231 cells. At the same time, in a bleomycin-induced pulmonary fibrosis model of C57BL / 6 mice, this 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative can effectively improve the degree of inflammation in the lung tissue of mice, has the potential for treating tumors and fibrotic diseases, and provides a highly potential candidate molecule for the drug discovery of ROCK2 inhibitors. Description of the drawings

[0090] Figure 1 Results of HE & Masson staining experiments on mouse lung tissue. Detailed implementation manners

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

[0092] In the following examples, the nuclear magnetic resonance hydrogen spectrum of the compound was measured by Bruker ARX-400 / 600, and the mass spectrum was measured by Agilent1100LC / MSD; all reagents used were of analytical purity or chemical purity.

[0093] Examples 1 - 31

[0094]

[0095]

[0096]

[0097] Example 1: N-(1H-indazol-5-yl)-3-[5-(morpholinomethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazin-6-amine (1);

[0098] The route is as follows:

[0099]

[0100] Step A1: Synthesis of intermediate a1

[0101] Dissolve 3-amino-6-pyridazine (10.0 g, 77.5 mmol) in DMF (100 mL). After adding DMF-DMA (18.47 g, 155 mmol), stir and react at 65 °C for 2 h. Concentrate the reaction solution under reduced pressure. Add sodium bicarbonate (9.77 g, 116.25 mmol), potassium iodide (2.57 g, 15.5 mmol) and bromoacetonitrile (18.59 g, 155 mmol), and stir and react at 85 °C for 2 h. After detecting the completion of the reaction by TLC, filter the reaction solution while it is hot. Add water (500 mL) to the filtrate and stir, then filter to obtain 11.2 g of a large amount of brown solid, with a yield of 81.2%.

[0102] Step A2: Synthesis of intermediate a2

[0103] Dissolve 1-(tetrahydro-2H-pyran-2-yl)-1H-indazol-5-amine (3.6 g, 16.58 mmol) and intermediate a1 (2.46 g, 13.82 mmol) in dioxane (20 mL). Add Pd 2 (dba) 3 (1.27 g, 1.38 mmol), XantPhos (1.60 g, 2.76 mmol) and cesium carbonate (13.51 g, 41.46 mmol). Under nitrogen protection, stir and react at 80 °C for 3 h. After detecting the completion of the reaction by TLC, concentrate the reaction solution, add tetrahydrofuran (20 mL) and stir, then filter. The filter cake is purified by column chromatography to obtain 4.2 g of a 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), hydroxylamine hydrochloride (0.58 g, 8.35 mmol) and triethylamine (1.13 g, 11.2 mmol) were added, and the mixture was stirred at 80 °C for 3 h. After the reaction was completed as detected by TLC, the reaction solution was evaporated to dryness to obtain 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), and chloroacetyl chloride (0.72 g, 9.36 mmol) was added dropwise under ice bath. After the addition was complete, the temperature was raised to 65 °C and the mixture was stirred for 2.5 h. After the reaction was completed as detected by TLC, 200 mL of water was added to the reaction solution and stirred, and the mixture was extracted three times with ethyl acetate (100 mL). The organic phase was evaporated to dryness, and the residue was purified by column chromatography to obtain 1.51 g of yellow-green solid, with a yield of 56.0%. Analytical data: ESI-MS [M+H] + (m / z): 451.0; 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.80 (s, 1H), 9.05 (s, 1H), 8.20 (s, 1H), 8.06 (d, J = 9.6 Hz, 1H), 7.99 (s, 1H), 7.70 (d, J = 13.4 Hz, 2H), 7.16 (d, J = 9.7 Hz, 1H), 5.84 (d, J = 9.5 Hz, 1H), 5.27 (s, 2H), 3.90 (s, 1H), 3.76 (s, 1H), 2.43 (d, J = 15.2 Hz, 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), morpholine (0.05 g, 0.6 mmol) and potassium carbonate (0.11 g, 0.8 mmol) were added, and the mixture was stirred at 60 °C for 4 h. After the reaction was completed as detected by TLC, 20 mL of water was added to the reaction solution and stirred, and then filtered by suction. 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, 5 mL of water was added and stirred, and the pH of the solution was adjusted to 8 with saturated sodium bicarbonate solution, and then 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 obtain 79 mg of pale yellow solid, with a yield of 47.3%. Analytical data: ESI-HRMS [M+Na] +(m / z): 440.1582; 1 HNMR (600 MHz, DMSO-d 6 ) δ 12.98 (s, 1H), 9.70 (s, 1H), 9.15 - 9.12 (m, 1H), 8.16 (s, 1H), 8.03 (d, J = 9.8 Hz, 1H), 7.98 (s, 1H), 7.58 - 7.51 (m, 2H), 7.13 (d, J = 9.7 Hz, 1H), 4.06 (s, 2H), 3.63 (t, J = 4.7 Hz, 4H), 2.61 (dd, J = 5.6, 3.7 Hz, 4H). 13 C NMR (151 MHz, DMSO) δ 176.23, 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] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with piperidine and then deprotecting under acidic conditions, Example 2 was obtained with a yield of 56.8%. Analytical data: ESI-MS [M + H] + (m / z): 416.1; 1 HNMR (600 MHz, DMSO-d 6 ) δ 12.99 (s, 1H), 9.70 (s, 1H), 9.14 (s, 1H), 8.17 (s, 1H), 8.03 (d, J = 9.7 Hz, 1H), 7.98 (s, 1H), 7.55 (d, J = 7.0 Hz, 2H), 7.14 (d, J = 9.7 Hz, 1H), 4.00 (s, 2H), 2.55 (t, J = 5.4 Hz, 4H), 1.56 - 1.53 (m, 4H), 1.40 - 1.37 (m, 2H). 13 C NMR (151 MHz, DMSO) δ 176.65, 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] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 4-hydroxypiperidine and then deprotecting under acidic conditions, Example 3 was obtained with a yield of 40.9%. Analytical data: ESI-HRMS [M+Na] + (m / z): 454.1743; 1 H NMR (600 MHz, DMSO-d 6 ) δ 13.02 (s, 1H), 9.81 (s, 1H), 9.15 (d, J = 1.9 Hz, 1H), 8.16 (s, 1H), 8.03 (d, J = 9.7 Hz, 1H), 7.96 (s, 1H), 7.59 - 7.51 (m, 2H), 4.62 (d, J = 4.2 Hz, 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, 3.9 Hz, 2H), 1.46 (tt, J = 13.2, 6.6 Hz, 2H). 13 C NMR (151 MHz, DMSO) δ 160.28, 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}ethan-1-ol (4);

[0115] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with N-hydroxyethylpiperazine and then deprotecting under acidic conditions, Example 4 was obtained with a yield of 32.4%. Analytical data: ESI-HRMS [M+Na] + (m / z): 483.2009; 1 H NMR (400 MHz, DMSO-d 6)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 - d 6 )δ176.16,160.30,151.85,139.22,136.51,135.06,133.96,133.51,126.35,123.76,120.35,117.29,115.70,110.72,108.72,59.51,55.59,52.73,52.13,50.84.

[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] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with cyclopropylamine and then de - protecting under acidic conditions, Example 5 was obtained with a yield of 49.5%. Analytical data: ESI - MS[M + Na] + (m / z): 410.0; 1 H NMR(600MHz,DMSO - d 6 )δ13.02(d,J=44.8Hz,1H),9.71(s,1H),9.17(s,1H),8.16(s,1H),8.09 - 7.94(m,2H),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]pyridazin-6-amine (6);

[0119] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with cyclopentylamine and then deprotecting under acidic conditions, Example 6 was obtained with a yield of 47.8%. Analytical data: ESI-HRMS [M+Na] + (m / z): 438.1792; 1 H NMR (600 MHz, DMSO-d 6 ) δ 12.99 (s, 1H), 9.71 (s, 1H), 9.18 (s, 1H), 8.15 (s, 1H), 8.03 (d, J = 9.7 Hz, 1H), 7.98 (s, 1H), 7.54 (d, J = 2.9 Hz, 2H), 7.14 (d, J = 9.7 Hz, 1H), 4.16 (s, 2H), 3.17 (p, J = 6.2 Hz, 1H), 1.75 (dq, J = 12.6, 6.3 Hz, 2H), 1.66 - 1.63 (m, 2H), 1.48 (td, J = 7.8, 7.2, 3.6 Hz, 2H), 1.43 - 1.37 (m, 3H). 13 C NMR (151 MHz, DMSO) δ 178.75, 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]pyridazin-6-amine (7);

[0121] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with N-methylcyclohexylamine and then deprotecting under acidic conditions, Example 7 was obtained with a yield of 50.1%. Analytical data: ESI-HRMS [M+Na] + (m / z): 466.2110; 1 H NMR (600 MHz, DMSO-d 6)δ12.99(s,1H),9.70(s,1H),9.16(t,J=1.4Hz,1H),8.15(s,1H),8.03(d,J=9.7Hz,1H),7.97(s,1H),7.58-7.51(m,2H),7.13(d,J=9.8Hz,1H),4.10(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)δ177.98,160.25,151.80,139.15,136.51,134.97,133.95,133.48,126.35,123.79,120.33,117.38,115.57,110.70,108.75,62.21,49.05,38.57,29.02,26.13,25.59.

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

[0123] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 4-fluoroaniline and deprotecting under acidic conditions, Example 8 was obtained with a yield of 59.2%. Analytical data: ESI-HRMS[M+Na] + (m / z): 464.1390; 1 H NMR(600MHz,DMSO-d 6 )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). 1313C NMR (151 MHz, DMSO) δ 160.34, 156.18, 154.64, 151.81, 144.76, 139.20, 136.50, 134.99, 133.93, 133.48, 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-[(phenylamino)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine (9);

[0125] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with aniline and then deprotecting under acidic conditions, Example 9 was obtained with a yield of 56.4%. Analytical data: ESI-HRMS [M+Na] + (m / z): 446.1483; 1 1H NMR (400 MHz, DMSO-d 6 ) δ 12.97 (s, 1H), 9.69 (s, 1H), 9.15 (s, 1H), 8.14 (s, 1H), 8.03 (d, J = 9.7 Hz, 1H), 7.92 (s, 1H), 7.59 - 7.48 (m, 2H), 7.20 - 7.04 (m, 3H), 6.74 (d, J = 8.0 Hz, 2H), 6.59 (dt, J = 22.0, 6.9 Hz, 2H), 4.80 (d, J = 6.5 Hz, 2H). 13 13C NMR (101 MHz, DMSO) δ 178.44, 160.36, 151.81, 148.10, 139.19, 136.51, 134.99, 133.93, 133.49, 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]pyridazin-6-amine (10);

[0127] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 2-chloroaniline and then deprotecting under acidic conditions, Example 10 was obtained with a yield of 44.7%. Analytical data: ESI-HRMS [M+Na]+ (m / z): 480.1099; 1 H NMR (400 MHz, DMSO-d 6 ) δ 12.96 (s, 1H), 9.73 (d, J = 10.9 Hz, 1H), 9.13 (dt, J = 5.1, 1.5 Hz, 1H), 8.12 (s, 1H), 8.03 (t, J = 9.3 Hz, 1H), 7.90 (s, 1H), 7.60 - 7.48 (m, 2H), 7.33 (dd, J = 7.9, 1.5 Hz, 1H), 7.22 - 7.04 (m, 2H), 6.86 (dd, J = 8.2, 1.4 Hz, 1H), 6.67 (td, J = 7.6, 1.4 Hz, 1H), 6.41 - 6.28 (m, 1H), 4.92 (d, J = 6.5 Hz, 2H). 13 C NMR (101 MHz, DMSO) δ 177.99, 160.39, 151.82, 143.77, 139.21, 136.53, 135.01, 133.94, 133.46, 129.72, 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]pyridazin-6-amine (11);

[0129] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 4-methoxybenzylamine and then deprotecting under acidic conditions, Example 11 was obtained with a yield of 55.2%. Analytical data: ESI-HRMS [M+Na] + (m / z): 490.1750; 1 H NMR (400 MHz, DMSO-d 6 ) δ 12.98 (s, 1H), 9.71 (s, 1H), 9.19 (t, J = 1.4 Hz, 1H), 8.15 (s, 1H), 8.03 (d, J = 9.8 Hz, 1H), 7.98 (s, 1H), 7.54 (d, J = 1.6 Hz, 2H), 7.34 - 7.27 (m, 2H), 7.14 (d, J = 9.8 Hz, 1H), 6.93 - 6.86 (m, 2H), 4.11 (s, 2H), 3.79 (s, 2H), 3.72 (s, 3H), 3.18 (d, J = 5.0 Hz, 1H). 1313C NMR (101 MHz, DMSO) δ 178.67, 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]pyridazin-6-amine (12);

[0131] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 4-fluorobenzylamine, deprotection was carried out under acidic conditions to obtain Example 12 with a yield of 59.3%. Analytical data: 13 13C NMR (101 MHz, DMSO) δ 178.60, 162.88, 160.25, 151.81, 139.14, 136.55, 134.93, 133.95, 133.55, 130.47, 130.39, 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]pyridazin-6-amine (13);

[0133] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 4-chloro-3-methoxybenzylamine, deprotection was carried out under acidic conditions to obtain Example 13 with a yield of 48.5%. Analytical data: ESI-HRMS [M+Na] + (m / z): 524.1357; 1 1H NMR (400 MHz, DMSO-d 6)δ12.97(s,1H),9.71(d,J=7.9Hz,1H),9.18(d,J=4.2Hz,1H),8.15(s,1H),8.04(dd,J=9.8,3.3Hz,1H),7.97(d,J=4.9Hz,1H),7.53(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]pyridazin - 6 - amine (14);

[0135] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 3,5 - difluorophenol, deprotection was carried out 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 - d 6 )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). 13 C 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]pyridazin - 6 - amine (15);

[0137] According to the method of step A5 in Example 1, using intermediate a4 as the raw material, after undergoing a nucleophilic substitution reaction with 3-methoxy-4-methylphenol, deprotection is carried out 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-d 6 ) 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-d 6 ) δ175.48, 160.47, 151.88, 149.87, 144.95, 139.22, 136.61, 134.98, 133.90, 133.40, 132.85, 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]pyridazin-6-amine (16);

[0139] The route is as follows:

[0140]

[0141] Step A6: Preparation of intermediate a5

[0142] Intermediate a2 (2.0 g, 5.6 mmol) was dissolved in DMF (20 mL). NaH (0.16 g, 6.72 mmol) was added. After stirring at room temperature for 30 min, methyl iodide (0.87 g, 6.16 mmol) was added, and the mixture was stirred at 45 °C for 2 h. After monitoring the reaction by TLC until completion, water (100 mL) was added to the reaction mixture and stirred. The mixture was filtered by suction, and the filter cake was dried to obtain 1.41 g of a yellowish-green solid with a yield of 67.5%. Analytical data: ESI-MS + (m / z): 396.5.

[0143] Step A7: Preparation of intermediate a6

[0144] According to the method of Step A3 in Example 1, using intermediate a5 as the raw material, after undergoing a nucleophilic addition reaction with hydroxylamine hydrochloride, intermediate a6 was obtained with a yield of 66.2%.

[0145] Step A8: Preparation of intermediate a7

[0146] According to the method of Step A4 in Example 1, using intermediate a6 as the raw material, after undergoing a cyclization reaction with chloroacetyl chloride, intermediate a7 was obtained with a yield of 43.5%.

[0147] Step A9: Preparation of Example 16

[0148] According to the method of Step A5 in Example 1, using intermediate a7 as the raw material, after undergoing a nucleophilic substitution reaction with 4-fluorobenzylamine and deprotecting under acidic conditions, Example 17 was obtained with a yield of 42.7%. Analytical data: 1 H NMR (600 MHz, DMSO-d 6 ) δ 13.26 (s, 1H), 8.12 (d, J = 5.2 Hz, 2H), 7.84 - 7.79 (m, 2H), 7.68 (d, J = 8.7 Hz, 1H), 7.44 - 7.39 (m, 2H), 7.36 (dd, J = 8.7, 2.0 Hz, 1H), 7.19 - 7.10 (m, 2H), 6.60 (d, J = 10.0 Hz, 1H), 4.07 (s, 2H), 3.83 (s, 2H), 3.51 (s, 3H). 13 C NMR (151 MHz, DMSO) δ 162.47, 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 as follows:

[0151]

[0152] Step A10: Preparation of intermediate a8

[0153] According to the method of Step A4 in Example 1, using intermediate a3 as the raw material, after cyclization reaction with ethyl oxalyl chloride, intermediate a8 was obtained with a yield of 41.5%.

[0154] Step A11: Preparation of Example 17

[0155] Dissolve intermediate a8 (0.15 g, 0.32 mmol) in ethanol (2 mL), add 4-fluorobenzylamine (0.12 g, 0.95 mmol), and reflux for 3 h. After monitoring the reaction by TLC until completion, the reaction solution was evaporated to dryness, water (10 mL) was added and stirred, and then filtered by suction. 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, water (5 mL) was added and stirred, the solution was adjusted to pH 8 with saturated sodium bicarbonate solution, extracted with dichloromethane (5 mL), the organic phase was dried over anhydrous sodium sulfate, and then evaporated to dryness. The crude product was purified by column chromatography to obtain 70 mg of pale yellow solid with a yield of 41.0%. Analytical data: ESI-HRMS + (m / z): 492.1305. 1 1H NMR (600 MHz, DMSO-d 6 ) δ 12.98 (s, 1H), 10.09 (t, J = 6.2 Hz, 1H), 9.74 (s, 1H), 9.17 (t, J = 1.4 Hz, 1H), 8.20 (s, 1H), 8.05 (d, J = 9.7 Hz, 1H), 8.01 (s, 1H), 7.53 (d, J = 1.5 Hz, 2H), 7.51 - 7.39 (m, 2H), 7.23 - 7.14 (m, 3H), 4.54 (d, J = 6.1 Hz, 2H). 1313C NMR (151 MHz, DMSO) δ 167.67, 161.47, 159.87, 159.62, 152.40, 150.75, 138.25, 134.13, 133.61, 132.67, 128.97, 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] According to the method of step A11 in Example 17, using intermediate a8 as the raw material, after ammonolysis reaction with 4-cyanobenzylamine, deprotection was carried out under acidic conditions to obtain Example 18 with a yield of 43.9%. Analytical data: 1 1H NMR (600 MHz, DMSO-d 6 ) δ 12.98 (s, 1H), 10.17 (d, J = 5.8 Hz, 1H), 9.75 (s, 1H), 9.18 (s, 1H), 8.21 (s, 1H), 8.07 - 7.99 (m, 2H), 7.85 (d, J = 8.0 Hz, 2H), 7.61 (d, J = 7.9 Hz, 2H), 7.54 (s, 2H), 7.17 (d, J = 9.8 Hz, 1H), 4.65 (d, J = 6.1 Hz, 2H). 13 13C NMR (151 MHz, DMSO) δ 168.72, 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 as follows:

[0160]

[0161] Step A12: Preparation of intermediate a9

[0162] According to the method of step A4 in Example 1, using intermediate a6 as the raw material, after undergoing a cyclization reaction with ethyl oxalyl chloride, intermediate a9 was obtained with a yield of 50.6%.

[0163] Step A13: Preparation of Example 19

[0164] According to the method of step A11 in Example 17, using intermediate a9 as the raw material, after undergoing an ammonolysis reaction with 4-fluorobenzylamine and then deprotecting under acidic conditions, Example 19 was obtained with a yield of 43.9%. Analytical data: ESI-HRMS [M+Na] + (m / z): 502.1717; 1 H NMR (600 MHz, DMSO-d 6 ) δ 13.27 (s, 1H), 10.01 (t, J = 6.2 Hz, 1H), 8.15 (d, J = 33.1 Hz, 2H), 7.86 - 7.80 (m, 2H), 7.69 (d, J = 8.7 Hz, 1H), 7.37 (dd, J = 8.7, 2.0 Hz, 1H), 7.27 (d, J = 7.7 Hz, 2H), 7.16 (d, J = 7.7 Hz, 2H), 6.62 (d, J = 10.0 Hz, 1H), 4.47 (d, J = 6.2 Hz, 2H), 3.52 (s, 3H), 2.29 (s, 3H). 13 C NMR (151 MHz, DMSO) δ 168.71, 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]thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine (20);

[0166] The route is as follows:

[0167]

[0168] Step A14: Preparation of intermediate a10

[0169] According to the method of step A3 in Example 1, using intermediate a2 as the raw material, reacting with aqueous ammonium sulfide solution, intermediate a10 was obtained with a yield of 75.1%. Analytical data: ESI-MS [M+H] + (m / z): 394.0;

[0170] Step A15: Preparation of intermediate a11

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

[0172] Step A16: Preparation of Example 20

[0173] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, reacting with 4-methylpiperidine in a nucleophilic substitution reaction, and then deprotecting 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 (600 MHz, DMSO-d 6 ) δ13.10 (s, 1H), 9.72 (s, 1H), 8.50 (d, J = 1.9 Hz, 1H), 8.16 (d, J = 19.0 Hz, 2H), 8.04 (d, J = 9.7 Hz, 1H), 7.92 (s, 1H), 7.61 (d, J = 8.8 Hz, 1H), 7.56 (dd, J = 8.9, 2.0 Hz, 1H), 7.12 (d, J = 9.7 Hz, 1H), 4.24 (s, 2H), 3.30 (s, 2H), 2.74 (s, 2H), 1.73 (d, J = 13.4 Hz, 2H), 1.54 (s, 1H), 1.34 (d, J = 12.2 Hz, 2H), 0.91 (d, J = 6.5 Hz, 3H). 13 C NMR (151 MHz, 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]thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine (21);

[0175] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after undergoing a nucleophilic substitution reaction with 4-methylpiperazine and then deprotecting under acidic conditions, Example 21 was obtained with a yield of 66.8%. Analytical data: ESI-HRMS [M+H] + (m / z): 446.1898; 1 H NMR (600 MHz, DMSO-d 6 ) δ 13.10 (s, 1H), 9.70 (s, 1H), 8.54 (d, J = 2.0 Hz, 1H), 8.14 (d, J = 15.0 Hz, 2H), 8.03 (d, J = 9.7 Hz, 1H), 7.73 (s, 1H), 7.62 - 7.53 (m, 2H), 7.11 (d, J = 9.7 Hz, 1H), 3.80 (s, 2H), 3.10 (q, J = 7.3 Hz, 4H), 2.78 (s, 4H), 1.19 (t, J = 7.3 Hz, 3H). 13 C NMR (151 MHz, DMSO) δ 153.97, 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]thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (22);

[0177] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after undergoing a nucleophilic substitution reaction with dimethylamine hydrochloride and then deprotecting under acidic conditions, Example 22 was obtained with a yield of 42.2%. Analytical data: ESI-HRMS [M+H] + (m / z): 391.1477; 1 H NMR (600 MHz, DMSO-d 6)δ 13.05 (s, 1H), 9.62 (s, 1H), 8.54 (s, 1H), 8.15 - 8.12 (m, 2H), 8.02 (d, J = 9.7 Hz, 1H), 7.64 (s, 1H), 7.58 (d, J = 11.5 Hz, 2H), 7.07 (d, J = 9.7 Hz, 1H), 3.63 (s, 2H), 2.25 (s, 6H). 13 C NMR (151 MHz, DMSO) δ 154.38, 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]thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (23);

[0179] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after undergoing a nucleophilic substitution reaction with cyclopentylamine and then deprotecting under acidic conditions, Example 23 was obtained with a yield of 51.8%. Analytical data: ESI-HRMS [M + H] + (m / z): 431.1800; 1 H NMR (600 MHz, DMSO-d 6 )δ 13.05 (s, 1H), 9.62 (s, 1H), 8.56 (d, J = 1.9 Hz, 1H), 8.13 (d, J = 9.5 Hz, 2H), 8.02 (d, J = 9.6 Hz, 1H), 7.62 (s, 1H), 7.60 - 7.52 (m, 2H), 7.07 (d, J = 9.7 Hz, 1H), 3.89 (s, 2H), 3.11 (p, J = 6.3 Hz, 1H), 1.76 (dq, J = 12.5, 6.4 Hz, 2H), 1.65 (q, J = 5.7 Hz, 2H), 1.56 - 1.34 (m, 5H). 13 C NMR (151 MHz, DMSO) δ 156.59, 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}thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (24);

[0181] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after undergoing a nucleophilic substitution reaction with cyclopropylmethylamine and then deprotecting under acidic conditions, Example 24 was obtained with a yield of 46.5%. Analytical data: ESI-HRMS [M+H] + (m / z): 417.1636; 1 H NMR (600 MHz, DMSO-d 6 ) δ 13.05 (s, 1H), 9.62 (s, 1H), 8.56 (d, J = 2.2 Hz, 1H), 7.62 (d, J = 1.0 Hz, 1H), 7.60 - 7.51 (m, 2H), 7.07 (d, J = 9.7 Hz, 1H), 3.94 - 3.91 (m, 2H), 2.49 (d, J = 6.7 Hz, 2H), 0.99 - 0.90 (m, 1H), 0.49 - 0.37 (m, 2H), 0.18 - 0.11 (m, 2H). 13 C NMR (151 MHz, DMSO) δ 156.67, 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}thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine (25);

[0183] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after undergoing a nucleophilic substitution reaction with N-methylcyclohexylamine and then deprotecting under acidic conditions, Example 25 was obtained with a yield of 66.7%. Analytical data: ESI-MS [M+H] + (m / z): 459.3; 1 H NMR (600 MHz, DMSO-d 6)δ13.08(s,1H),9.68(s,1H),8.52 - 8.49(m,1H),8.15(d,J=12.6Hz,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),2.89(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),1.61(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}thiazol - 2 - yl}-N-(1H - indazol - 5 - yl)imidazo[1,2 - b]pyridazin - 6 - amine (26);

[0185] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after carrying out a nucleophilic substitution reaction with 4 - fluoroaniline and de - protecting under acidic conditions, Example 26 was obtained with a yield of 72.6%. Analytical data: ESI - HRMS[M + Na] + (m / z): 479.1197; 1 H NMR(400MHz,DMSO - d 6 )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=9.7Hz,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). 13¹³C NMR (101 MHz, DMSO) δ 156.05, 155.58, 154.04, 153.75, 152.27, 145.66, 138.07, 137.06, 133.63, 133.00, 131.60, 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}thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine (27);

[0187] According to the method of step A5 in Example 1, using intermediate a11 as the raw material, after undergoing a nucleophilic substitution reaction with 4-methoxybenzylamine and deprotecting under acidic conditions, Example 27 was obtained with a yield of 63.1%. Analytical data: ESI-HRMS [M+H] + (m / z): 483.1751; 1 ¹H NMR (400 MHz, DMSO-d 6 ) δ 13.05 (s, 1H), 9.62 (s, 1H), 8.56 (s, 1H), 8.13 (d, J = 4.9 Hz, 2H), 8.02 (d, J = 9.7 Hz, 1H), 7.65 (s, 1H), 7.57 (q, J = 9.0 Hz, 2H), 7.31 (d, J = 8.1 Hz, 2H), 7.07 (d, J = 9.7 Hz, 1H), 6.89 (d, J = 8.1 Hz, 2H), 6.32 - 4.76 (m, 1H), 3.88 (s, 2H), 3.74 (d, J = 2.6 Hz, 5H). 13 ¹³C NMR (101 MHz, DMSO) δ 158.63, 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}thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine (28);

[0189] The synthetic route is as follows:

[0190]

[0191] Step A17: Preparation of intermediate a12

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

[0193] Step A13: Preparation of intermediate a13

[0194] According to the method of step A3 in Example 1, using intermediate a12 as the raw material, after reacting with an aqueous solution of ammonium sulfide, intermediate a10 was obtained with a yield of 77.4%.

[0195] Step A14: Preparation of intermediate a14

[0196] According to the method of step A4 in Example 1, using intermediate a13 as the raw material, after undergoing a cyclization reaction with 1,3-dichloroacetone, intermediate a14 was obtained with a yield of 58.4%.

[0197] Step A15: Preparation of Example 28

[0198] According to the method of step A5 in Example 1, using intermediate a14 as the raw material, after undergoing a nucleophilic substitution reaction with 4-methoxybenzylamine and then deprotecting under acidic conditions, Example 28 was obtained with a yield of 63.1%. Analytical data: ESI-HRMS [M+Na] + (m / z): 547.2002; 1 H NMR (600 MHz, DMSO-d 6 ) δ13.33 (s, 1H), 8.16 (d, J = 9.0 Hz, 2H), 7.77 - 7.69 (m, 3H), 7.57 (s, 1H), 7.28 (dd, J = 36.6, 8.4 Hz, 3H), 6.90 (d, J = 8.1 Hz, 2H), 6.16 (d, J = 10.1 Hz, 1H), 5.19 - 5.16 (m, 1H), 3.88 (s, 2H), 3.75 (s, 3H), 3.45 (t, J = 5.4 Hz, 2H), 3.33 - 3.25 (m, 1H), 1.26 (d, J = 6.5 Hz, 6H). 1313C NMR (151 MHz, DMSO) δ 158.61, 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-(pyrrolidin-1-yl)acetamide (29);

[0200] The synthetic route is as follows:

[0201]

[0202] Step A16: Preparation of intermediate a15

[0203] Dissolve 3-amino-6-chloropyridazine (1.0 g, 7.72 mmol) in ethanol (10 mL) and water (5 mL), add bromoacetaldehyde diethyl acetal (3.0 g, 15.2 mmol) and hydrobromic acid (0.7 mL), and reflux for 8 h. After monitoring the reaction by TLC and completion, evaporate the reaction solution to dryness. Add the residue to saturated sodium carbonate solution (10 mL), stir, filter, wash the filter cake with water and dry to obtain 1.05 g of off-white solid, with a yield of 89.1%.

[0204] Step A17: Preparation of intermediate a16

[0205] Dissolve intermediate a15 (1.0 g, 6.54 mmol) in dichloromethane (10 mL). Under ice bath, add NBS (1.3 g, 7.19 mmol) in portions and stir at room temperature for 4 h. After monitoring the reaction by TLC and completion, wash the reaction solution twice with saturated sodium bicarbonate solution (10 mL), separate the organic phase, dry over anhydrous sodium sulfate and evaporate to dryness to obtain 1.38 g of yellow solid, with a yield of 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(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (0.18 g, 0.22 mmol) was added. Under nitrogen protection, the mixture was stirred at 80 °C for 4 h. After monitoring the reaction by TLC until completion, the reaction solution was evaporated to dryness, ethyl acetate (20 mL) was added and stirred, and then filtered through diatomaceous earth. The filtrate was washed twice with saturated sodium chloride solution (20 mL), and the organic phase was evaporated to dryness. The crude product was purified by column chromatography to obtain 0.85 g of a yellowish-green solid, with a yield of 71.7%.

[0208] Step A19: Preparation of intermediate a18

[0209] According to the method of step A2 in Example 1, using intermediate a17 as the raw material, a Buchwald-Hartwig coupling reaction was carried out with 1-(tetrahydro-2H-pyran-2-yl)-1H-indazol-5-amine to obtain intermediate a18, 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). Reductive iron powder (0.15 g, 2.64 mmol) and saturated aqueous ammonium chloride solution (1 mL) were added, and the mixture was refluxed for 6 h. After monitoring the reaction by TLC until completion, the reaction solution was filtered while hot, and the filtrate was evaporated to dryness. The residue was stirred with saturated sodium bicarbonate solution and then filtered. The crude product was purified by column chromatography to obtain 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). At low temperature, chloroacetyl chloride (0.03 g, 0.28 mmol) was slowly added dropwise, and the mixture was stirred at room temperature for 1 h. After monitoring the reaction by TLC until completion, the reaction solution was poured into water (10 mL) and stirred, and then filtered. The filter cake was dried to obtain 0.1 g of a yellow solid, with a yield of 83.3%

[0214] Step A22: Preparation of Example 29

[0215] According to the method of step A5 in Example 1, using intermediate a20 as the raw material, after a nucleophilic substitution reaction with pyrrolidine, deprotection was carried out 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 (600 MHz, DMSO-d 6 ) δ 12.98 (s, 1H), 9.88 (s, 1H), 9.49 (s, 1H), 8.47 (d, J = 2.0 Hz, 1H), 8.30 (t, J = 1.9 Hz, 1H), 7.94 (d, J = 9.6 Hz, 2H), 7.88 (s, 1H), 7.81 (d, J = 7.1 Hz, 2H), 7.74 (dd, J = 8.1, 2.2 Hz, 1H), 7.55 - 7.49 (m, 2H), 7.44 (dd, J = 8.9, 2.0 Hz, 1H), 6.99 (d, J = 9.7 Hz, 1H), 3.36 (s, 2H), 2.57 (d, J = 6.1 Hz, 4H), 1.71 - 1.68 (m, 4H). 13 C NMR (151 MHz, DMSO) δ 169.09, 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] According to the method of step A5 in Example 1, using intermediate a20 as the raw material, after undergoing a nucleophilic substitution reaction with isopropylamine and then deprotecting under acidic conditions, Example 30 was obtained 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-yl}phenyl}-2-(cyclohexyl(ethyl)amino)acetamide (31);

[0219] According to the method of step A5 in Example 1, using intermediate a20 as the raw material, after undergoing a nucleophilic substitution reaction with N-ethylcyclohexylamine and then deprotecting under acidic conditions, Example 31 was obtained with a yield of 44.7%. Analytical data: ESI-HRMS [M+H] + (m / z): 509.2806; 1 H NMR (600 MHz, 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)δ171.33,151.31,138.96,137.43,136.56,133.95,133.37,130.80,130.08,129.48,128.02,126.63,123.52,122.62,120.66,119.19,118.31,113.68,110.82,108.42,61.13,54.79,46.52,29.01,26.06,25.86,14.08.

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

[0221] According to the method of step A5 in Example 1, using intermediate A4 as the raw material, after undergoing a nucleophilic substitution reaction with 4-methoxybenzyl mercaptan and sodium hydride, deprotection was carried out under acidic conditions to obtain Example 32 with a yield of 21.9%. Analytical data: ESI-MS [M + H] + (m / z): 485.0; 1 H NMR(400MHz,DMSO-d 6)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]pyridazin-6-amine;

[0223] Dissolve Example 32 (0.2 g, 0.41 mmol) in hexafluoroisopropanol (2 mL), add 30% hydrogen peroxide solution (0.1 mL), and stir the reaction at room temperature for 2 h. After monitoring the reaction by TLC until completion, pour the reaction solution into water (10 mL), stir, filter by suction, and purify the filter cake by column chromatography to obtain 0.15 g of Example 33, with a yield of 71.4%. Analytical data: ESI-MS [M+H] + (m / z): 501.0; 1 HNMR(400MHz,DMSO-d 6 )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),7.54(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). 1313C NMR (101 MHz, DMSO) δ 178.52, 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]pyridazin-6-amine;

[0225] Dissolve Example 32 (0.2 g, 0.41 mmol) in glacial acetic acid (2 mL), add 30% hydrogen peroxide solution (1 mL) and sodium tungstate (0.01 g, 0.04 mmol), and stir the reaction at room temperature for 3 h. After monitoring the reaction by TLC until completion, pour the reaction solution into water (10 mL), stir, filter by suction, and purify the filter cake by column chromatography to obtain 0.16 g of Example 34 with a yield of 76.2%. Analytical data: ESI-MS + (m / z): 517.0; 1 1H NMR (400 MHz, DMSO-d 6 ) δ 12.97 (s, 1H), 9.71 (s, 1H), 9.18 (d, J = 2.3 Hz, 1H), 8.18 (s, 1H), 8.04 (d, J = 9.8 Hz, 1H), 7.97 (s, 1H), 7.53 (d, J = 1.5 Hz, 2H), 7.38 - 7.25 (m, 2H), 7.14 (d, J = 9.8 Hz, 1H), 6.96 - 6.87 (m, 2H), 4.60 (s, 2H), 4.35 (s, 2H), 3.81 (s, 3H). δ 178.75, 160.38, 158.63, 151.79, 139.15, 136.48, 134.98, 133.97, 133.57, 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: Conduct anti-tumor and anti-fibrotic activity experiments on the compounds prepared in the above examples

[0227] I. In vitro ROCK2 inhibitory activity

[0228] Use Promega The kinase detection kit was used to test the inhibitory effect of the above-obtained compounds on ROCK2. The compound to be tested was prepared into a 10 mM stock solution with DMSO and serially diluted three-fold with the 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 compound solutions with different concentrations. In a white flat-bottom 96-well plate, 20 μL of ROCK2 enzyme solution (1 nM), 10 μL of the compound solution, 10 μL of the reaction substrate (20 μM RSK2 peptide KKRNRTLTK), and 10 μL of the ATP solution (10 μM) were added to each well in sequence and incubated at room temperature for 3 h. 50 μL of the reaction detection solution in the kit was added to each well to terminate the reaction, and the chemiluminescence signal was detected using a Tecan multi-functional microplate reader. All dose settings had three replicates, and non-linear fitting was performed using GraphPad Prism 8 to calculate the IC 50 value.

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

[0230] Table 1 Results of the inhibition of ROCK2 activity by compounds

[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 above, the compounds obtained in the present invention have a high inhibitory activity against ROCK2, and most of the IC 50 values are below 100 nM, which is better than the positive control Belumosudil.

[0233] II. CCK-8 assay for the cytotoxicity of tumor cells and fibroblasts

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

[0235] The cells were cultured in DMEM medium containing 10% fetal bovine serum in a 37 °C incubator containing 5% CO 2 and the medium was changed every 2 - 3 days. When the cells grew to 80% - 90% density, they were digested with trypsin and centrifuged to collect the cells. The collected cells were resuspended with serum-containing medium and diluted to 2×104 A suspension of cells at a density of cells / mL. The cell suspension was inoculated into a 96-well cell culture plate at a density of 100 μL / well and incubated overnight. The culture medium was changed, and the test compounds or the solvent (DMSO) at the above-described concentration gradients were added, and the cells were incubated in an incubator for 48 hours. After the treatment, the culture medium in the plate was discarded, and the cells were washed twice with PBS. Then, 100 μL of CCK-8 working solution was added to each well, and the plate was incubated at 37 °C in the dark for 1.5 hours. The absorbance values of each well at 450 nm were measured on an ELISA reader, and the CC 50 values of each compound were analyzed and calculated.

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

[0237] Table 2 Results of the anti-proliferative activities of some compounds against MDA-MB-231 cells and TGF-β-NIH / 3T3 cells

[0238]

[0239] As can be seen from the above, some compounds obtained in the present invention have anti-proliferative effects on both 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 the two cell lines, and their CC50 values are all below 1 μM.

[0240] III. Anti-pulmonary fibrosis activity in vivo

[0241] Animal model experiments based on bleomycin-induced pulmonary fibrosis in C57BL / 6 mice were conducted on some compounds in the present invention.

[0242] Forty 6- to 8-week-old C57BL / 6 mice (male, weighing 20-22 g) were randomly divided into 4 groups of 10 mice each. They were fasted for 12 hours before modeling, with water available ad libitum. All experimental mice were anesthetized by intraperitoneal injection of a 2% sodium pentobarbital solution at a dose of 0.05 mg / kg. After no response, the mice were vertically suspended and their limbs were fixed. A cannula was inserted through the glottis fissure of the mice into the trachea, and tracheal instillation was performed. Each mouse was instilled with a 3 U / kg bleomycin sulfate solution (BLM) to induce a pulmonary fibrosis model. Seven days after modeling, the mice were given different concentrations of the compound obtained in Example 11 (50 mg / kg or 100 mg / kg) by gavage once a day. Fourteen days after administration, the lung tissues of the mice were taken for HE and Masson staining to observe the alveolar wall thickness, the degree of neutrophil infiltration, and the collagen fiber area. At the same time, the lung tissues of healthy C57BL / 6 mice were used as negative controls.

[0243] As Figure 1 shown, after the lung tissues of the mice in the model group were induced by bleomycin, the alveolar morphology collapsed, the alveolar walls thickened, and there was a large amount of inflammatory cell infiltration and collagen fiber deposition. After administration of Compound 11, the alveolar walls thinned and the collagen fiber deposition decreased significantly. When the concentration of Compound 11 administered was 100 mg / kg, the pulmonary morphology basically 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 in that: The derivatives are compounds represented by the general formula (I) and pharmaceutically acceptable salts thereof. Where: R1 is hydrogen, (C1-C6)alkyl and (C1-C6)acyl which are unsubstituted or substituted by at least one identical or different R3; R3 is hydroxy, amino, cyano, carboxyl, (C1-C6) alkoxy or (C1-C6) alkylamino; A is a 5-10 membered aryl or heteroaryl group, wherein the heteroaryl group contains 1-4 heteroatoms selected from N, O and S; X is m is independently 1, 2 or 3; R2 is -NR4R5, -OR4, -SR4, R4 and R5 are the same or different and are independently selected from hydrogen, (C1-C6) alkyl, (C3-C6) cycloalkyl, 5-10 membered aryl or heteroaryl which are unsubstituted or substituted by at least one R6 which is the same or different; or R4 and R5 together with the nitrogen atom to which they are attached form a 4-8 membered heterocyclyl or heteroaryl, which is optionally substituted by 0-3 independent R6; R6 is halogen, hydroxy, amino, carboxyl, cyano, (C1-C6) alkyl, (C3-C6) cycloalkyl, (C6-C 10 )aryl, (C1-C6)alkoxy or (C1-C6)alkylamino; R7 is halogen, hydroxy, amino, cyano, (C1-C6) alkyl, (C1-C6) alkoxy or (C1-C6) alkylamino.

2. The 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 1, characterized in that The derivatives are compounds represented by the general formula (I) and pharmaceutically acceptable salts thereof, wherein: R1 is hydrogen, unsubstituted or substituted by at least one identical or different R3 (C1-C6) alkyl; R3 is hydroxy, amino, cyano, carboxyl, or (C1-C6) alkoxy; A is a 5-8 membered aryl or heteroaryl group, wherein the heteroaryl group contains 1-4 heteroatoms selected from N, O and S; X is m is independently 1 or 2; R2 is -NR4R5, -OR4, -SR4, R4 and R5 are the same or different and are independently selected from hydrogen, (C1-C6) alkyl, (C3-C6) cycloalkyl, 5-8 membered aryl or heteroaryl which are unsubstituted or substituted by at least one R6 which is the same or different; or R4 and R5 together with the nitrogen atom to which they are attached form a 4-8 membered heterocyclyl or heteroaryl, which is optionally substituted by 0-3 independent R6; R6 is halogen, hydroxy, amino, cyano, (C1-C6) alkyl, (C3-C6) cycloalkyl, (C6-C 10 )aryl, (C1-C6)alkoxy or (C1-C6)alkylamino; R7 is halogen, hydroxy, amino, cyano, (C1-C6) alkyl, (C1-C6) alkoxy or (C1-C6) alkylamino.

3. The 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 2, characterized in that: The derivatives are compounds represented by the general formula (I) and pharmaceutically acceptable salts thereof, wherein: R1 is hydrogen, unsubstituted or substituted by at least one identical or different R3 (C1-C3) alkyl; R3 is hydroxy, amino, cyano, carboxyl, or (C1-C3) alkoxy; A is a 5-8 membered aryl or heteroaryl group, wherein the heteroaryl group contains 1-4 heteroatoms selected from N, O and S; X is m is independently 1 or 2; R2 is -NR4R5, -OR4, -SR4, R4 and R5 are the same or different and are independently selected from hydrogen, (C1-C6) alkyl, (C3-C6) cycloalkyl, 5-8 membered aryl or heteroaryl which are unsubstituted or substituted by at least one identical or different R6; or R4 and R5 together with the nitrogen atom to which they are attached form a 4-6 membered heterocyclic group which is optionally substituted by 0-2 independent R6; R6 is halogen, hydroxy, amino, cyano, phenyl which is unsubstituted or substituted by at least one R7, (C1-C3) alkyl, (C3-C6) cycloalkyl, (C1-C3) alkoxy or (C1-C3) alkylamino; R7 is halogen, hydroxy, amino, cyano, (C1-C3) alkyl or (C1-C3) alkoxy.

4. The 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 3, characterized in that: The derivatives are compounds represented by the general formula (I) and pharmaceutically acceptable salts thereof, wherein: R1 is hydrogen, (C1-C3) alkyl; A is a 5-6 membered aryl or heteroaryl group, wherein the heteroaryl group contains 1-3 heteroatoms selected from N, O and S; X is R2 is -NR4R5, -OR4, -SR4, R3 and R4 are the same or different and are independently selected from hydrogen, (C1-C6) alkyl, (C3-C6) cycloalkyl, phenyl which are unsubstituted or substituted by at least one identical or different R6; or R3 and R4 together with the nitrogen atom to which they are attached form a 4-6 membered heterocyclic group which is optionally substituted by 0-1 independent R6; R6 is halogen, hydroxy, cyano, phenyl which is unsubstituted or substituted by at least one R7, (C1-C3) alkyl, (C3-C6) cycloalkyl or (C1-C3) alkoxy; R7 is halogen, (C1-C3) alkyl or (C1-C3) alkoxy.

5. The 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 4, characterized in that The derivatives are compounds represented by the general formula (I) and pharmaceutically acceptable salts thereof, wherein: R1 is hydrogen, methyl or isopropyl; A is X is R2 is 6. The 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 5, characterized in that Specifically selected from the following compounds: N-(1H-indazol-5-yl)-3-[5-(morpholinomethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-[5-(piperidin-1-ylmethyl)-1,2,4-oxadiazol-3-yl]imidazo[1,2-b]pyridazin-6-amine; 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; 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}ethan-1-ol; 3-{5-[(cyclopropylamino)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{5-[(cyclopentylamino)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{5-{[cyclohexyl(methyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{5-{[(4-fluorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{5-[(anilino)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine; 3-{5-{[(2-chlorophenyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine; 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{5-{[(3-chloro-4-methoxybenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{5-[(3,5-difluorophenoxy)methyl]-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{5-[(2-methoxy-4-methylphenoxy)methyl]-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine; 3-{5-{[(4-fluorobenzyl)amino]methyl}-1,2,4-oxadiazol-3-yl}-N-(1H-indazol-5-yl)-N-methylimidazo[1,2-b]pyridazin-6-amine; 3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-fluorobenzyl)-1,2,4-oxadiazole-5-carboxamide; 3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-cyanobenzyl)-1,2,4-oxadiazole-5-carboxamide; 3-{6-[(1H-indazol-5-yl)(methyl)amino]imidazo[1,2-b]pyridazin-3-yl}-N-(4-methylbenzyl)-1,2,4-oxadiazole-5-carboxamide; N-(1H-indazol-5-yl)-3-{4-[(4-methylpiperidin-1-yl)methyl]thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{4-[(4-methylpiperazin-1-yl)methyl]thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine; 3-{4-[(dimethylamino)methyl]thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{4-[(Cyclopentylamino)methyl]thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{4-{[(cyclopropylmethyl)amino]methyl}thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{4-{[cyclohexyl(methyl)amino]methyl}thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; 3-{4-{[(4-fluorophenyl)amino]methyl}thiazol-2-yl}-N-(1H-indazol-5-yl)imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-N-isopropyl-3-{4-{[(4-methoxybenzyl)amino]methyl}thiazol-2-yl}imidazo[1,2-b]pyridazin-6-amine; N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(pyrrolidin-1-yl)acetamide; N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-yl}phenyl}-2-(isopropylamino)acetamide; N-{3-{6-[(1H-indazol-5-yl)amino]imidazo[1,2-b]pyridazin-3-ylphenyl}-2-(cyclohexyl(ethyl)amino)acetamide; N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)thio]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)sulfinyl]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine; N-(1H-indazol-5-yl)-3-{5-{[(4-methoxybenzyl)sulfonyl]methyl}-1,2,4-oxadiazol-3-yl}imidazo[1,2-b]pyridazin-6-amine.

7. The 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to any one of claims 1 to 6, characterized in that: The salt of the compound represented by the 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 or succinic acid, fumaric acid, salicylic acid, phenylacetic acid or mandelic acid.

8. Use of the 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 1, characterized in that: The compound represented by the general formula (I) and its pharmaceutically acceptable salt are used as ROCK2 inhibitors.

9. The use of the 3-substituted imidazo[1,2-b]pyridazine-6-amine derivative according to claim 8, characterized in that: The compound represented by the general formula (I) and its pharmaceutically acceptable salt are used in the preparation of drugs for treating tumors or fibrotic diseases.

10. The use according to claim 9, characterized in that: The tumor is 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.

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