Imidazopyridazine derivatives, their preparation methods, pharmaceutical compositions and uses

Abstract

The present invention relates to imidazo[1,2-a]pyridazine derivatives, a preparation method thereof, a pharmaceutical composition and uses thereof. The present invention provides a compound represented by formula (1), its stereoisomers, tautomers, prodrugs, pharmaceutically acceptable salts, amorphous substances, isotopomers, polymorphs or solvates. A pharmaceutical composition containing the compound and the use of the compound as a GABA A receptor modulator, wherein R1, R2 and R3 are as defined in the specification.

Description

Technical Field

[0001] The present invention relates to imidazopyridazine derivatives having a regulatory function on GABA A receptors, a preparation method thereof, a pharmaceutical composition, and their use as drugs. Background Art

[0002] γ-aminobutyric acid (GABA) is an important inhibitory neurotransmitter in the mammalian central nervous system. Substances that regulate GABAergic neurotransmission are widely used in the treatment of various diseases, such as epilepsy, anxiety, and depression. In nature, there are two types of GABA receptors. One is the GABA A receptor (GABA A R), which is a member of the ligand-gated ion channel superfamily. The other is the GABA B receptor (GABA B R), which is a member of the G protein-coupled receptor superfamily. The GABA A receptor subunits found in mammals include α1-6, β1-4, γ1-3, δ, ε, θ, and ρ1-2 subunits. Among them, α subunits, β subunits, and γ subunits are essential for forming a complete functional GABA A receptor, and the α subunit is crucial for the binding of benzodiazepine compounds to the GABA A receptor.

[0003] Drugs that bind to allosteric binding sites can be positive allosteric modulators (or direct allosteric modulators) that increase receptor activity, negative allosteric modulators (or inverse allosteric modulators) that decrease receptor activity, or neutral allosteric modulators that do not change receptor activity (referring to compounds that bind to allosteric binding sites but do not regulate receptor activity). Recent evidence suggests that GABA A receptors containing α2 or α3 subunits (referred to herein as α2 / 3-GABA A receptors) may be involved in certain pain states, and positive allosteric modulators of these receptors may be effective analgesics (Mirza, N.R. and Munro, G., Drug News and Perspectives, 2010, 23(6), 351-360).

[0004] International patent applications PCT / GB01 / 04948 (published as WO2002 / 038568) and PCT / GB02 / 03114 (published as WO2003 / 008418) describe 7-phenylimidazo[1,2-b][1,2,4]triazine derivatives which have an affinity for the α2, α3 and / or α5 subunits. International patent application PCT / US99 / 14935 (published as WO2000 / 001697) particularly discloses 4-phenyl-7H-imidazo[4,5-c]pyridazine derivatives which are corticotropin-releasing factor antagonists. International patent applications PCT / IB2013 / 060631 (published as WO2014 / 091368) and PCT / IB2015 / 054200 (publication number WO2015 / 189744) and an article by Robert M. Owen (Robert M. Owen, J. Med. Chem. 2019, 62, 5773-5796) describe 4-(biphenyl-3-yl)-7H-imidazo[4,5-c]pyridazine derivatives which interact with the α2 / 3-GABA A receptor and are useful for the treatment of a variety of diseases including pain. Such compounds have also been used in the treatment of pruritus (International patent application PCT / US2019 / 033598, publication number WO2019 / 26820A1) and epilepsy (CNS Neurosci Ther. 2019.25(2): p. 255-260. by Duveau, V.).

[0005] The prevailing view is that the regulatory activity on the GABA A receptor containing the α1 subunit is the main source of side effects (such as sedation, addiction, drowsiness, amnesia) of current GABA A modulators (such as benzodiazepines) (Uwe Rudolph and Frederic Knoflach, Nature Reviews: Drug Discovery, 2011, 10(9), 685-697). Searching for new compounds that interact with the GABA A receptor and have fewer α1-GABA A receptor-related side effects will have great therapeutic potential. SUMMARY OF THE INVENTION

[0006] According to one aspect of the present invention, there is provided a compound of formula (1), its stereoisomers, tautomers, prodrugs, pharmaceutically acceptable salts, amorphous forms, polymorphs or solvates:

[0007]

[0008] Wherein,

[0009] R1 is a fused group formed by a substituted or unsubstituted heterocycle and a heterocycle;

[0010] R2 is selected from H, halogen, OH, C1-C6 alkoxy or CN;

[0011] R3 is selected from H, a substituted or unsubstituted straight-chain or branched C1-C6 alkyl, or a substituted or unsubstituted C3-C6 cycloalkyl.

[0012] Unless otherwise specified, the following definitions are used to illustrate and define the meanings and scopes of various terms used in this article to describe the present invention.

[0013] Whether occurring alone or in combination, the following definitions of general terms apply.

[0014] The nomenclature rules used in this application are based on AutoNomTM 2000, a computerized system of the Beilstein Institute for generating IUPAC system names. The chemical structures given in this article were obtained using ChemDraw version 12. Any open valence bond appearing on a carbon, oxygen, sulfur, or nitrogen atom in the structures given in this article indicates the presence of a hydrogen atom.

[0015] Unless otherwise specified, the term "substituted" means that the specified group or moiety may have 1, 2, 3, 4, 5, or 6 substituents. When a group may have multiple substituents and multiple possible substituents are given, the substituents are independently selected and do not have to be the same.

[0016] The term "unsubstituted" means that the specified group does not have a substituent.

[0017] The term "optionally substituted" means that the specified group is unsubstituted or is substituted by one or more substituents independently selected from the possible substituents.

[0018] When the number of substituents is specified, the term "one or more" means one substitution to the maximum possible number of substitutions, i.e., substituting one hydrogen to all hydrogens being substituted by substituents. Unless otherwise specified, 1, 2, 3, 4, or 5 substituents are preferred.

[0019] Specifically, in the group definitions of R1 and R3, "substituted" means that one or more hydrogens on the group are substituted by an alkyl selected from C1-C4, an alkoxy selected from C1-C4, a halogen-substituted alkyl selected from C1-C4, or a halogen.

[0020] The term "halogen" means fluorine, chlorine, bromine, and iodine, preferably fluorine.

[0021] The compounds of the present invention may contain asymmetric or chiral centers and, accordingly, exist in different stereoisomeric forms. All stereoisomeric forms of the compounds of the present invention, including but not limited to, diastereomers, enantiomers, and atropisomers, as well as mixtures thereof such as racemic mixtures, will form part of the present invention. In this text, when the stereochemistry of any particular chiral atom is not determined, all stereoisomers are contemplated. In addition, the present invention relates to all geometric and positional isomers. The compounds of the present invention may exist in different tautomeric forms, and all such forms are included within the scope of the present invention. All stereoisomers of the compounds of the present invention are expected to include mixtures or pure or substantially pure forms. They may be resolved by physical methods such as fractional crystallization, separation or crystallization of diastereomeric derivatives, or by chiral column chromatography.

[0022] The term "prodrug" is a functional derivative of a compound of formula (1) which is readily convertible in vivo into a compound of formula (1). Suitable derivatives can be selected and prepared by conventional techniques well known to those skilled in the art, see, for example, Design of Prodrugs, ed. H. Bundgaard, Elsevier, 1985.

[0023] As used herein, the term "pharmaceutically acceptable salt" refers to pharmaceutically acceptable organic or inorganic salts of the compounds of the present invention. Exemplary salts include but are not limited to sulfate, citrate, acetate, oxalate, chloride, bromide, iodide, nitrate, bisulfate, isonicotinate, lactate, salicylate, acid citrate, succinate, maleate, fumarate, gluconate, formate, mesylate, and pamoate. "Pharmaceutically acceptable salts" may involve including another molecule such as maleate or other counterions. Counterions stabilize the charge in the parent compound. "Pharmaceutically acceptable salts" may have more than one charged atom, and multiple charged atoms may have multiple counterions.

[0024] If the compound of the present invention is a base, the required "pharmaceutically acceptable salt" can be prepared by suitable methods, for example, by treating the free base with the following inorganic acids: hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid; or with the following organic acids: acetic acid, maleic acid, succinic acid, mandelic acid, fumaric acid, malonic acid, pyruvic acid, salicylic acid, pyranosyl acids such as glucuronic acid or galacturonic acid, α-hydroxy acids such as citric acid or tartaric acid, amino acids such as glutamic acid, aromatic acids such as benzoic acid or cinnamic acid, sulfonic acids such as methanesulfonic acid or p-toluenesulfonic acid.

[0025] If the compound of the present invention is an acid, the required "pharmaceutically acceptable salts" can be prepared by suitable methods, for example, treating the free acid with an inorganic base or an organic base such as amines, alkali metal hydroxides or alkaline earth metal hydroxides. Exemplary examples of suitable salts include but are not limited to organic salts derived from amino acids, primary, secondary and tertiary amine salts, and salts of cyclic amines such as piperidine, morpholine and piperazine, as well as inorganic salts derived from sodium, calcium, potassium, magnesium, manganese, iron, copper, zinc, aluminum and lithium.

[0026] The compounds of the present invention can exist in a continuous solid state ranging from completely amorphous to completely crystalline. The term "amorphous" refers to a state in which the material lacks long-range order at the molecular level and, depending on the temperature, can exhibit the physical properties of a solid or a liquid. Typically, such materials do not give a distinct X-ray diffraction pattern and, while exhibiting solid properties, are more formally described as liquids. Upon heating, a change from solid to liquid properties occurs, characterized by a change in state, typically a second-order ("glass transition"). The term "crystal" refers to a solid phase in which the material has a regularly ordered internal structure at the molecular level and gives a unique X-ray diffraction pattern with defined peaks. Such materials will also exhibit liquid properties upon sufficient heating, but the change from solid to liquid is characterized by a phase change, typically a first-order ("melting point").

[0027] The term "polymorph" as used herein refers to different solid crystalline phases of certain compounds of the present invention resulting from the presence of two or more different molecular arrangements in the solid state. Certain compounds of the present invention can exist in more than one crystalline form, and the present invention is intended to include all crystalline forms and their mixtures.

[0028] The term "solvate" as used herein refers to an adduct or complex of one or more solvent molecules with a compound of the present invention. Examples of solvents that form solvates include but are not limited to water, isopropanol, ethanol, methanol, dimethyl sulfoxide, ethyl acetate, acetic acid and ethanolamine. The compounds of the present invention can exist in unsolvated form or in solvated form with pharmaceutically acceptable solvents such as water, ethanol, etc., and thus the present invention will include solvated and unsolvated forms.

[0029] Compounds of the present invention may contain unnatural proportions of atomic isotopes on one or more atoms constituting the compound. The term "isotopologue" has the same number of atoms, but its atomic mass or mass number is different from the atomic mass or mass number that preponderantly exists in nature. For example, compounds can be labeled with radioactive isotopes such as deuterium (2H), tritium (3H), iodine-125 (125I), or C-14 (14C). All transformations of the isotopic composition of the compounds of the present invention, whether radioactive or not, are included within the scope of the present invention. Isotopic variants may enhance certain therapeutic advantages, such as deuterium enrichment can increase the in vivo half-life or reduce the dosage requirement, or can provide standard compounds that can be used for the characterization of biological samples. By conventional techniques well known to those skilled in the art, or by methods similar to those described in the routes and examples herein, using appropriate isotopically enriched reagents and / or intermediates, isotopically enriched compounds within formula (1) can be prepared without undue experimentation.

[0030] [R2]

[0031] In the compounds of the present invention, R2 is selected from H, halogen, OH, C1-C6 alkoxy, or CN; preferably, R2 is preferably H or halogen, more preferably H or F.

[0032] [R3]

[0033] In the compounds of the present invention, R3 is selected from H, substituted or unsubstituted straight-chain or branched C1-C6 alkyl, or substituted or unsubstituted C3-C6 cycloalkyl. In R3, the C1-C6 alkyl can be straight-chain or branched. Exemplary C1-C6 alkyls include methyl, ethyl, n-propyl (1-propyl), isopropyl (2-propyl, 1-methylethyl), n-butyl (1-butyl), sec-butyl (2-butyl, 1-methylpropyl), isobutyl (2-methylpropyl), or tert-butyl (1,1-dimethylethyl). One or more hydrogen atoms on the above alkyls can be substituted by substituents such as methyl, ethyl, n-propyl, methoxy, ethoxy, propoxy, fluoromethyl, fluoroethyl, fluorine, chlorine, bromine, etc.

[0034] The term "cycloalkyl" refers to a monovalent saturated cyclic hydrocarbon group. In R3, exemplary C3-C5 cycloalkyls include cyclopropyl, cyclobutyl, or cyclopentyl.

[0035] In R3, exemplary C3-C6 cycloalkyl groups include 1-methylcyclopropyl, 2-methylcyclopropyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1-methylcyclopentyl, 2-methylcyclopentyl or 3-methylcyclopentyl. One or more hydrogen atoms on the above cycloalkyl groups may be substituted by substituents such as methyl, ethyl, n-propyl, methoxy, ethoxy, propoxy, fluoromethyl, fluoroethyl, fluorine, chlorine, bromine, etc.

[0036] The term "alkoxy" refers to alkyloxy. In R3, exemplary C1-C6 alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, etc. One or more hydrogen atoms on the above alkoxy groups may be substituted by substituents such as methyl, ethyl, n-propyl, methoxy, ethoxy, propoxy, fluoromethyl, fluoroethyl, fluorine, chlorine, bromine, etc.

[0037] In a preferred embodiment of the present invention, R3 is selected from straight-chain or branched C1-C6 alkyl groups, C1-C6 alkoxy groups, more preferably C2-C4 alkyl groups, and even more preferably ethyl or isopropyl.

[0038] [R1]

[0039] In the solution of the present invention, R1 is a heterocyclic fused group. The two heterocycles independently refer to saturated or partially unsaturated monocyclic or polycyclic groups having heteroatoms, and the heteroatoms are N, O or S. Preferably, the two heterocycles independently are 3-7 membered saturated or partially unsaturated monocyclic or polycyclic groups containing 1-3 ring heteroatoms selected from N, O or S. S and O can exist as -SO or SO2.

[0040] Preferably, the two heterocycles independently are 5-7 membered saturated or unsaturated monocyclic groups containing 1, 2 or 3 ring heteroatoms selected from N, O or S. Preferably, the two heterocycles independently are 5-6 membered saturated or unsaturated monocyclic groups containing 1, 2 or 3 ring heteroatoms selected from N or O.

[0041] Preferably, R1 has the structures shown in formula (2), (3), (4), (5), (6) or (7):

[0042]

[0043]

[0044] Specifically,

[0045] R4 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C1-C6 alkylthio or C1-C6 alkylsulfonyl; the above groups (including the alkyl, cycloalkyl, alkoxy, alkylthio or alkylsulfonyl involved) may optionally be unsubstituted or independently substituted by 1-4 substituents each independently selected from halogen, hydroxy, C1-C3 alkyl, halo C1-C3 alkyl, C1-C3 alkoxy or halo C1-C3 alkoxy;

[0046] R5 is selected from hydrogen, halogen, hydroxy, oxo, C1-C6 alkylcarbonyl, C1-C6 alkylamide, C1-C6 alkoxyimino, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C6-C10 aryl, 5-10 membered heteroaryl containing 1-3 heteroatoms, C1-C6 non-aromatic heterocycle containing 1-3 heteroatoms; the above groups (including the alkylcarbonyl, alkylamide, alkoxyimino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, aryl, heteroaryl, non-aromatic heterocycloalkyl involved) may optionally be unsubstituted or independently substituted by 1-4 substituents each independently selected from halogen, hydroxy, C1-C3 alkyl, halogen-substituted C1-C3 alkyl, C1-C3 alkoxy or 3-7 membered heterocycloalkyl of C1-C6 containing 1-3 N or O heteroatoms;

[0047] The A ring refers to a 5-7 membered saturated or partially unsaturated monocyclic group containing N, m is 1, 2 or 3, n is 1 or 2, preferably, m is 1 and n is 1, represents the connection site.

[0048] R1 is connected to the phenyl group of the compound of formula (1) through

[0049] When R4 or R5 is a substituent on the heterocycle, it can be connected to a heteroatom or a carbon atom.

[0050] In the R5 group, the heteroatom is selected from N, O or S.

[0051] In some preferred embodiments, R4 is selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, vinyl, ethynyl, cyclopropyl, cyclobutyl, methoxy, ethoxy, n-propoxy, -CH2-O-CH3, methylsulfonyl or ethylsulfonyl; the above groups may optionally be unsubstituted or independently substituted by C1-C3 alkoxy or halogen. Preferably, R4 is selected from H, C1-C3 alkyl, C1-C3 alkoxy-substituted C1-C3 alkyl or C1-C3 alkoxy, most preferably methoxymethyl or methoxy.

[0052] ​In certain preferred embodiments, R5 is selected from hydrogen, F, Cl, Br, hydroxyl, formyl, acetyl, formamido, acetamido, methoxyimino, ethoxyimino, methyl, ethyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, phenyl, benzyl, tetrahydrofuranyl, hexahydropyranyl, hexahydropyridyl, oxetane, azetidine; the above groups may be optionally unsubstituted or independently substituted by 1-4 substituents each independently selected from F, Cl, Br, hydroxyl, methoxy, methyl, pyrrolidine, morpholinyl or -CH2-CF3.

[0053] In a more preferred embodiment, R5 is selected from H, methyl, ethyl, isopropyl, cyclopropyl, fluorocyclopropyl, or

[0054] Ring A refers to a 5- or 6-membered saturated or unsaturated monocyclic group containing 1, 2 or 3 N heteroatoms.

[0055] In certain preferred embodiments, when R1 has the structure shown in formula (2) or (7), Ring A has the following structure:

[0056] or

[0057] indicating the connection site; the R5 is as defined in any one of the foregoing of the present invention.

[0058] In certain preferred embodiments, when R1 has the structure shown in formula (3), (4), (5) or (6), Ring A has the following structure:

[0059] or

[0060] indicating the connection site; the R5 is as defined in any one of the foregoing of the present invention.

[0061] In the solution of the present invention, R1 is a substituted or unsubstituted pyridine-fused heterocycle; more preferably, R1 is a substituted or unsubstituted pyrido-triazole or a substituted or unsubstituted pyrido-imidazole.

[0062] As a more preferred solution, R1 is selected from any one of the following compounds:

[0063] or

[0064] Among them, represents a linking site.

[0065] R4 and R5 are as defined in any one of the foregoing of the present invention.

[0066] As a preferred structure, R1 is selected from any one of the following structures:

[0067] or And,

[0068] R4 is selected from methoxy C1-C3 alkyl or C1-C3 alkoxy; more preferably methoxymethyl or methoxy;

[0069] R5 is selected from H, methyl, ethyl, isopropyl, cyclopropyl, fluorocyclopropyl,

[0070] More preferably, the compound of the present invention has the structure shown in Table 1 below.

[0071] Table 1 Preferred compound structures

[0072]

[0073]

[0074]

[0075]

[0076]

[0077] The present invention also provides a pharmaceutical mixture, which contains two or more compounds selected from the group consisting of: the compound according to any one of the present invention or its stereoisomers, tautomers, prodrugs, pharmaceutically acceptable salts, amorphous forms, isotopomers, polymorphs or solvates.

[0078] The present invention also provides a pharmaceutical composition, which contains at least one of the compound according to any one of the present invention or its stereoisomers, tautomers, prodrugs, pharmaceutically acceptable salts, amorphous forms, isotopomers, polymorphs or solvates, and optionally adds a pharmaceutically acceptable carrier and / or adjuvant.

[0079] The compound according to any one of the present invention or its stereoisomers, tautomers, prodrugs, pharmaceutically acceptable salts, amorphous forms, polymorphs, solvates, the pharmaceutical mixture, or the pharmaceutical composition in the preparation of treating or preventing diseases related to GABAA Use in drugs for receptor-related diseases.

[0080] Further, the diseases related to the GABA A receptor are selected from at least one of the following: pain, Alzheimer's disease, multi-infarct dementia, and stroke.

[0081] Further, the pain is neuropathic pain, inflammatory pain, and cancer pain.

[0082] Further, the pain is selected from: headache, facial pain, neck pain, shoulder pain, back pain, chest pain, abdominal pain, back pain, lumbar pain, lower limb pain, muscle and bone pain, vascular pain, gout, arthritis pain, visceral pain, pain caused by infectious diseases, polyostotic pain, sickle cell anemia, autoimmune diseases, pain related to multiple sclerosis or inflammation, chronic pain caused by injury or surgery, nociceptive pain, painful diabetes, trigeminal neuralgia, lumbosacral or cervical radiculopathy, glossopharyngeal neuralgia, autonomic reflex pain, reflex sympathetic dystrophy, nerve root avulsion, cancer, chemical injury, toxin, nutritional deficiency, viral or bacterial infection, or pain related to degenerative osteoarthropathy.

[0083] The present invention also provides a method for treating or preventing diseases related to the GABA A receptor, by administering to a patient an effective dose of the compound or its stereoisomer, tautomer, prodrug, pharmaceutically acceptable salt, amorphous form, polymorph, solvate, the drug mixture, or the pharmaceutical composition according to any one of the present invention.

[0084] The present invention also provides a method for treating or preventing pain, Alzheimer's disease, multi-infarct dementia, or stroke, by administering to a patient an effective dose of the compound or its stereoisomer, tautomer, prodrug, pharmaceutically acceptable salt, amorphous form, polymorph, solvate, the drug mixture, or the pharmaceutical composition according to any one of the present invention.

[0085] The present invention also relates to a method for preparing the compound of formula (1) as described above, comprising:

[0086]

[0087] Note: The experimental operations are the same when R3 is ethyl or isopropyl.

[0088] Z-1a: 5-chloro-N3-ethylpyridazine-3,4-diamine

[0089] 3,5-Dichloropyridazin-4-amine (80.5 g, 0.5 mol) and ethanamine alcohol solution (30%, 600 ml) were placed in an autoclave and reacted at 150 °C for 16 hours. After the reaction solution cooled to room temperature, a solid precipitated. It was filtered, and the filter cake was washed with dichloromethane (300 ml). The mother liquor was concentrated (without evaporating to dryness), and a solid precipitated. It was filtered again. This was repeated 3 times, and all the filter cakes were collected to obtain the crude product (containing ethylamine hydrochloride). Water was added to the crude product, and it was stirred and slurried, then filtered. The filter cake was dried by rotary evaporation to obtain 65 g (76.5% yield) of the target product as a pale yellow solid. LC-MS: m / z [M+H] + = 173.

[0090] Z-2a: 4-chloro-7-ethyl-7H-imidazo[4,5-c]pyridazine

[0091] 5-Chloro-N3-ethylpyridazine-3,4-diamine (30 g, 0.17 mol) was added to trimethyl orthoformate (600 ml). The reaction was carried out at 120 °C for 4 hours. The reaction solution was directly dried by rotary evaporation to obtain the crude product. The crude product was dissolved in dichloromethane and methanol, and the sample was mixed and passed through a column (dichloromethane, dichloromethane / methanol = 50 / 1, V / V). 20 g (63% yield) of the target product as a yellow solid was obtained. LC-MS: m / z [M+H] + = 183.

[0092] Z-3a: 4-(3-chloro-4-fluorophenyl)-7-ethyl-7H-imidazo[4,5-c]pyridazine

[0093] 4-Chloro-7-ethyl-7H-imidazo[4,5-c]pyridazine (20 g, 108 mmol), (3-chloro-4-fluorophenyl)boronic acid (19.08 g, 108 mmol), sodium carbonate (24 g, 216 mmol), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (9.2 g, 10.8 mmol) were added to 1,4-dioxane / water (160 ml / 40 ml), and the reaction was carried out at 90 °C for 2 hours. The reaction solution was directly purified by column chromatography (petroleum ether / ethyl acetate = 10 / 1, 5 / 1, 1 / 1, ethyl acetate, V / V.) to obtain the title compound as a yellow solid (26 g, 85.7% yield). LC-MS: m / z [M+H] + = 277.

[0094] Z-4a-1: 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine Z-4a-2: (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid

[0095] 4-(3-Chloro-4-fluorophenyl)-7-ethyl-7H-imidazo[4,5-c]pyridazine (15 g, 54 mmol), bis(pinacolato)diboron (27.6 g, 108 mmol), sodium acetate (13 g, 163 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (2.7 g, 5.4 mmol), and tris(dibenzylideneacetone)dipalladium(0) (5 g, 5.4 mmol) were added to anhydrous 1,4-dioxane (150 mL), and the mixture was stirred at 110 °C overnight. The reaction mixture was purified directly by column chromatography (dichloromethane / methanol anhydrous = 50 / 1) to give the title compound as a pale yellow solid (12 g, 60% yield). 1 H NMR (400 MHz, CHLOROFORM-d) ppm 1.40 (s, 12H) 1.69 (t, J = 7.09 Hz, 3H) 4.58 (q, J = 7.34 Hz, 2H) 7.26 (d, J = 6.36 Hz, 1H) 8.29 (s, 1H) 8.45 (d, J = 1.96 Hz, 2H) 9.39 (s, 1H). LC-MS: m / z [M+H] + = 287, 369.

[0096] 1-1: (4-bromo-2-fluoropyridin-3-yl)methanol 7-Ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (12 g, 32.5 mmol) was dissolved in 200 mL of aqueous hydrochloric acid solution (2 M), and the mixture was stirred at room temperature for 2 hours and then lyophilized to give the title compound (9.3 g, crude product) as a white solid.

[0097] The compound of formula (1) of the present invention and its pharmaceutically acceptable salts can be prepared by the above methods.

[0098] If the preparation method is not described in the examples, the compound of formula (1) and its intermediate products can be prepared according to similar methods or according to the foregoing methods. Raw materials known in the art can be obtained commercially or can be prepared according to known methods in the art or similar methods of known methods.

[0099] It is understood that the compound of formula (1) of the present invention can be derivatized on the functional groups to obtain derivatives that can be reconverted into the parent compound in vivo.

[0100] Accordingly, the present invention also relates to a pharmaceutical composition comprising a compound as defined above or a pharmaceutically acceptable salt or prodrug thereof and a pharmaceutically acceptable carrier and / or adjuvant.

[0101] Similarly, the present invention also includes the compound or composition as described above, which is used for preparing a medicament for treating or preventing diseases related to the α2 / 3-GABA A receptor, especially for treating or preventing the following diseases: pain, epilepsy, anxiety, pruritus and depression.

[0102] Preferably for treating or preventing pain.

[0103] More preferably for treating or preventing neuropathic pain, inflammatory pain and cancer pain.

[0104] As used herein, "cancer pain" refers to the pain that occurs during the development of a malignant tumor. It is currently believed that there are three mechanisms for the occurrence of cancer pain, namely: pain directly caused by the development of cancer, pain caused after cancer treatment, and pain caused by concurrent painful diseases in cancer patients.

[0105] As used herein, "neuropathic pain" is the pain stimulated or caused by primary damage and dysfunction of the nervous system.

[0106] As used herein, "inflammatory pain" is the pain caused by local acute inflammation or chronic inflammation stimulating the nerves.

[0107] As used herein, "treatment" also includes prophylactic administration to relieve or eliminate the disease once the disease state is established.

[0108] As used herein, "patient" is defined as any warm-blooded animal, such as but not limited to mice, guinea pigs, dogs, horses or humans, and preferably the patient is a human.

[0109] As used herein, "acute pain" is defined as the pain caused by noxious stimuli resulting from injury and / or disease of the skin, body structures or viscera, or the pain caused by abnormal functions of muscles or viscera that do not produce actual tissue damage.

[0110] As used herein, "chronic pain" is defined as pain that persists beyond the usual course of an acute illness or a reasonable time for an injury to heal, or is associated with a chronic pathological process that causes persistent pain, or the pain recurs at intervals for months or years. If pain persists after it should have healed or beyond the usual course of treatment, it is considered chronic pain. The length of time pain needs to persist depends on the nature of the pain and the treatment process associated with it. If the pain exceeds the usual course of treatment, the pain is chronic. Chronic pain includes, but is not limited to, headache, facial pain, neck pain, shoulder pain, chest pain, abdominal pain, back pain, low back pain, lower limb pain, muscle and bone pain, pain associated with somatoform disorders, visceral pain, painful diabetic neuropathy, vascular pain, gout, arthritic pain, cancer pain, autonomic reflex pain, pain caused by infectious diseases (such as AIDS and shingles), pain caused by autoimmune diseases (rheumatism), pain caused by acute and chronic inflammation, postoperative pain, and post-burn pain.

[0111] The drug disclosed in the present invention can effectively treat chronic pain as defined above, and the drug disclosed in the present invention can be used to treat pain sensitivity associated with other conditions, including hyperalgesia, allodynia, hyperpathia, and enhanced pain memory. This invention will improve the treatment of pain.

[0112] As used herein, "headache" can be divided into primary headache and secondary headache. Primary headache includes tension headache, migraine, and cluster headache, while secondary headache is caused by other diseases. When pathological changes or stimuli occur in the pain-sensitive tissues of the head and face, various headaches can be caused. These pain-sensitive tissues include those distributed in the scalp, face, oral cavity, and throat, etc. Since they are mainly the muscles or blood vessels of the head and contain rich nerve fibers and are relatively sensitive to pain, headache can be caused when these tissues are damaged.

[0113] As used herein, "facial pain" includes, but is not limited to, trigeminal neuralgia, atypical facial pain, facial nerve palsy, and hemifacial spasm.

[0114] As used herein, "trigeminal neuralgia" is a unique chronic pain disorder, also known as tic douloureux, which refers to brief, paroxysmal, and recurrent electric shock-like severe pain in the distribution area of the trigeminal nerve, or accompanied by ipsilateral hemifacial spasm. Trigeminal neuralgia is divided into two types: primary and secondary. Primary trigeminal neuralgia means that no neurological signs are found clinically and no organic lesions are found upon examination; secondary trigeminal neuralgia means that neurological signs are found clinically and organic lesions are found upon examination, such as tumors and inflammation, etc.

[0115] As used herein, "atypical facial pain" refers to pain caused by various etiologies. It is manifested as persistent burning pain, without intermittence, unrelated to specific movements or trigger stimuli. The pain is mostly bilateral and often extends beyond the distribution of the trigeminal nerve and even involves the neck skin. The etiologies can be due to sinusitis, malignant tumors, infections of the jaw and skull base, etc., which stimulate or damage the trigeminal nerve and cause pain.

[0116] As used herein, "neck pain, back pain, shoulder pain" refers to pain caused by acute and chronic muscle strain, degenerative changes and trauma of bone joints, etc. Common diseases causing neck, shoulder and upper limb pain include neck and shoulder myofascial pain syndrome, nuchal ligament inflammation, cervical spondylosis, scapulohumeral periarthritis, thoracic outlet syndrome, lateral epicondylitis of humerus, etc. Or pain caused by autoimmune diseases is common in diseases such as rheumatoid arthritis, ankylosing spondylitis and rheumatic arthritis. Other diseases that may cause neck pain, back pain and shoulder pain also include tumors, neuritis, arteriovenous diseases and various infections of the neck and shoulders, as well as referred pain caused by lesions of thoracic and abdominal viscera.

[0117] As used herein, "chest, abdomen and back pain" refers to pain caused by diseases of the chest and abdominal viscera and chest and abdominal wall tissues, including but not limited to intercostal neuralgia, costal chondritis, angina pectoris, abdominal pain (acute abdominal visceral pain) and lumbodorsal myofascial syndrome.

[0118] As used herein, "low back and lower limb pain" refers to pain in the lower back, lumbosacral region, sacroiliac joint, hip, buttock and lower limb. Low back and lower limb pain is often not an independent disease, but a common feature of many diseases. The clinical manifestations are diverse and the etiologies are very complex, mostly degenerative and traumatic, including but not limited to pain involved in lumbar disc herniation, acute lumbar sprain, sciatica, osteoporosis, third lumbar transverse process syndrome, piriformis syndrome, knee osteoarthritis, coccydynia and heel pain, etc.

[0119] As used herein, "muscle and bone pain" includes but not limited to myofascial pain, pain caused by trauma and complex regional pain syndrome.

[0120] As used herein, "painful diabetes" refers to pain caused by nerve damage associated with diabetes, where the nerve damage in diabetes is at least partially due to reduced blood flow and hyperglycemia. Some diabetic patients do not develop neuropathy, while others develop the disease early. Diabetic neuropathic pain can be classified into mononeuropathy involving one or more focal sites and generalized polyneuropathy, where the polyneuropathy can be diffuse and symmetric and typically mainly involves sensory modalities (Merrit’s Textbook of Neurology, 9th Edition, edited by LP Rowland LP). Manifestations of diabetic neuropathy can include autonomic dysfunction, leading to dysregulation involving the heart, smooth muscle, and glands, causing hypotension, diarrhea, constipation, and sexual impotence. Diabetic neuropathy often develops in stages. In the early stage, in the nerve terminal area, autonomic neuropathy or sensory neuropathy occurs in the feet, and cranial neuropathy occurs in the face and around the eyes, presenting with intermittent pain and tingling. In subsequent stages, the pain is stronger and more frequent. Finally, when there is loss of pain sensation in a region, it becomes painless neuropathy, and due to the absence of pain as an indicator of injury, the risk of severe tissue damage is greatly increased.

[0121] As used herein, "visceral pain" includes, but is not limited to, pain associated with irritable bowel syndrome (IBS), with or without chronic fatigue syndrome (CFS), inflammatory bowel disease (IBD), and interstitial cystitis.

[0122] As used herein, "vascular pain" is pain produced by one or more of the following factors. First, improper perfusion of tissues, causing temporary or continuous local ischemia, such as local ischemia in limb muscles during exercise; second, delayed changes, such as ulcers or gangrene in the skin or abdominal viscera; third, sudden or accelerated changes in the caliber of large blood vessels, such as changes occurring in aneurysms; fourth, rupture of the aorta, resulting in blood spillage and stimulation of nociceptive fibers in the peritoneal or pleural parietal layer; fifth, severe spasm caused by severe irritation of the arterial endothelium during intra-arterial injection; sixth, impairment of venous blood return, resulting in massive edema rapidly expanding the fascial compartment (Bonica et al., The Management of Pain, Volume I (2nd Edition), Philadelphia; Lea&Feboger, 1990). Examples include, but are not limited to, atherosclerotic obliterans, thromboangiitis obliterans, acute arterial occlusion, embolism, congenital arteriovenous aneurysm, vasospastic diseases, Raynaud's disease, acrocyanosis, acute venous occlusion, thrombophlebitis, varicose veins, and lymphedema.

[0123] As used herein, "autonomic reflex pain" refers to pain caused by "reflex sympathetic dystrophy". Reflex sympathetic dystrophy refers to the condition in which, after acute or chronic injury to the body, there is severe spontaneous pain, hypersensitivity to touch and pain, accompanied by swelling and blood circulation disorders, and subsequently symptoms such as trophic disorders and atrophy of the skin and musculoskeletal system may occur.

[0124] As used herein, "postoperative pain" refers to a complex physiological response of the body to tissue damage caused by the disease itself and surgery, which is manifested as an unpleasant experience in terms of psychology and behavior.

[0125] As used herein, "arthritic pain" includes, but is not limited to, pain caused by diseases such as osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, gout, pseudogout, infectious arthritis, tendinitis, bursitis, bone lesions, and inflammation of the soft tissues of joints.

[0126] As used herein, "postherpetic neuralgia" refers to severe pain that persists subcutaneously in the area of the original rash after the rash of herpes zoster has healed.

[0127] As used herein, "nociceptive pain" is pain caused by the process of tissue damage transmitted by stimulation of nociceptors, or pain caused by prolonged excitation of nociceptors. Pain caused by prolonged excitation of nociceptors can be caused by persistent noxious stimulation of nociceptors or their sensitization or both, or they can be caused by these factors and prolonged by their persistence, various reflex mechanisms, and other factors.

[0128] The present invention provides the use of a pharmaceutical compound containing a therapeutically effective amount of an α2 / 3-GABA A positive allosteric modulator. Although the α2 / 3-GABA A positive allosteric modulator can be administered in the form of the raw material compound, it is preferably mixed with one or more additives, excipients, carriers, buffers, diluents, and / or other conventional pharmaceutical excipients to form a pharmaceutical composition, optionally in the form of a physiologically acceptable salt of the active ingredient.

[0129] In a preferred embodiment, the present invention provides a pharmaceutical composition containing an α2 / 3-GABA A positive allosteric modulator, wherein the α2 / 3-GABA A positive allosteric modulator is mixed with one or more pharmaceutically acceptable carriers and, optionally, with other therapeutic and / or prophylactic components known in the art or used. The carrier must be "acceptable", i.e., compatible with the other components in the formulation and not harmful to its recipient.

[0130] Thus, the compounds useful in the present invention can be made into pharmaceutical compositions and their unit dosage forms together with conventional additives or diluents. Such forms include solids (especially in the form of tablets, filled capsules, powders and pills), and liquids (especially aqueous or non-aqueous solutions, suspensions, emulsions, elixirs), and capsules filled with the above forms, all forms for oral administration, suppositories for rectal administration, and sterile injectable solutions for parenteral administration. Such pharmaceutical compositions and their unit dosage forms can include conventional components in conventional proportions, with or without additional active compounds or ingredients, and such unit dosage forms can contain any suitable effective amount of the active ingredient corresponding to the desired daily dosage range.

[0131] The compounds useful in the present invention can be administered in a variety of oral and parenteral dosage forms. To those skilled in the art, the following dosage forms can contain the compounds of the present invention or their pharmaceutically acceptable salts as active ingredients.

[0132] To make the compounds useful in the present invention into pharmaceutical compositions, the pharmaceutically acceptable carrier can be solid or liquid. Solid form preparations include powders, tablets, pills, capsules, cachets, suppositories, and dispersible granules. The solid carrier can be one or more substances that also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, preservatives, tablet disintegrants, or encapsulating materials.

[0133] In powders, the carrier is a finely divided solid which is mixed with the finely divided active ingredient.

[0134] In tablets, the active ingredient is mixed with the carrier having the necessary binding properties in appropriate proportions and compressed into the desired shape and size.

[0135] Powders and tablets preferably contain 5% or 10% to about 70% of the active compound. Suitable carriers are magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, low melting waxes, cocoa butter, and the like. The term "preparation" includes the active compound formulated with an encapsulating material as the carrier, and the encapsulating material provides a capsule in which the active ingredient with or without the carrier is surrounded by the carrier and thus bound together. Similarly, preparations include cachets and lozenges. Tablets, powders, capsules, pills, cachets and lozenges can be used as solid forms suitable for oral administration.

[0136] To prepare suppositories, first melt a mixture of a low melting wax, such as a fatty acid glyceride or cocoa butter, and then disperse the active ingredient uniformly therein by stirring. Then pour the melted and uniform mixture into a mold of appropriate size and let it cool and thus solidify.

[0137] Compositions suitable for vaginal administration may be in the form of vaginal suppositories, tampons, creams, gels, pastes, foams or sprays, and the composition contains, in addition to the active ingredient, a suitable carrier known in the art.

[0138] Liquid preparations include solutions, suspensions and emulsions, for example, aqueous solutions or water-propylene glycol solutions. For example, parenteral injection liquid preparations can be formulated as solutions of water-polyethylene glycol.

[0139] Therefore, the compounds used in the present invention can be formulated into preparations for parenteral administration (such as injection, such as rapid bolus injection or continuous infusion), and can be present in ampoules, pre-filled syringes, small-volume infusion bags or multi-dose containers in unit doses together with added preservatives. The composition can be in the form of a suspension, solution or emulsion of an oily or aqueous carrier, and can contain formulation ingredients such as suspending agents, stabilizers and / or dispersing agents. In addition, the active ingredient can be in the form of a powder, which can be obtained by sterile isolation of a solid or by lyophilization of a solution, for reconstitution with a suitable carrier such as sterile, pyrogen-free water immediately before use.

[0140] An aqueous solution suitable for oral administration can be prepared by dissolving the active ingredient in water and adding the required coloring agents, flavoring agents, stabilizers and thickening agents.

[0141] An aqueous suspension suitable for oral administration can be prepared by dispersing the finely divided active ingredient in water containing a viscous substance such as natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, or other well-known suspending agents.

[0142] Also included are solid preparations designed to be converted into liquid preparations for oral administration shortly before use. Such liquid preparations include solutions, suspensions and emulsions. In addition to the active ingredient, such preparations can contain coloring agents, flavoring agents, stabilizers, buffering agents, artificial and natural sweeteners, dispersing thickening agents, solubilizing agents, etc.

[0143] For topical application to the epidermis, the compounds of the present invention can be formulated into ointments, creams or lotions or transdermal patches. For example, ointments and creams can be formulated with aqueous or oily bases plus suitable thickening agents and / or gelling agents. Lotions can be formulated with aqueous or oily bases and usually also contain one or more emulsifying agents, stabilizers, dispersing agents, suspending agents, thickening agents or coloring agents.

[0144] Compositions suitable for topical oral administration include lozenges containing the active ingredient in a flavored matrix, usually sucrose and acacia or tragacanth; pastilles containing the active ingredient in an inert matrix such as gelatin and glycerin or sucrose and acacia; and mouthwashes containing the active ingredient in a suitable liquid carrier.

[0145] Solutions or suspensions can be applied directly to the nasal cavity by conventional methods, such as with a dropper, pipette or nebulizer. The composition can be in single-dose or multi-dose form.

[0146] Administration to the respiratory tract can also be achieved by aerosol, wherein the active ingredient is contained in a pressurized package together with a suitable propellant, and suitable propellants include chlorofluorocarbons (CFCs) such as dichlorodifluoromethane, trichlorofluoromethane or dichlorotetrafluoroethane, carbon dioxide or other suitable gases. The aerosol may also suitably contain a surfactant, such as lecithin. The dose of the drug can be controlled by a metering valve.

[0147] Alternatively, the active ingredient can be in the form of a dry powder, such as a powder mixture of the compound with a suitable powder matrix such as lactose, starch, starch derivatives such as hydroxypropylmethylcellulose and polyvinylpyrrolidone (PVP). The powder carrier can conveniently form a gel in the nasal cavity. The powder composition can be in unit-dose form, for example, present in a capsule or cartridge (such as a gelatin capsule or cartridge), or present in a blister pack from which the powder can be administered via an inhaler.

[0148] In compositions for administration to the respiratory tract (including intranasal compositions), generally the compound has a small particle size, for example, a particle size of the order of 5 microns or less. Such a particle size can be obtained by methods known in the art, such as by micronization.

[0149] When needed, compositions suitable for sustained release of the active ingredient can be applied.

[0150] The pharmaceutical preparation is preferably in unit-dose form. In such form, the preparation is subdivided into unit doses of a suitable amount of the active ingredient. The unit-dose form can be an encapsulated preparation, wherein the sealed package contains discrete multiple preparations, such as encapsulated tablets, capsules and powders contained in vials or ampoules. In addition, the unit-dose form can be the capsule, tablet, cachet or lozenge itself, or can be any appropriately encapsulated amount of the above capsules, tablets, etc.

[0151] Tablets or capsules for oral administration and liquids for intravenous administration and continuous infusions are preferred compositions.

[0152] More detailed information on formulations and administration techniques can be found in the latest edition of Remington's Pharmaceutical Sciences (Maack Publishing Co., Easton, PA).

[0153] The amount of the active ingredient in the unit dose formulation can vary depending on the specific application and the potency of the active ingredient, and can be adjusted from 0.01 mg to about 0.1 g. For example, in pharmaceutical use, the drug can be administered three times a day in capsules of 0.01 to about 100 mg, and the composition can also contain other compatible therapeutic agents if necessary.

[0154] Method of treatment

[0155] In therapeutic use, the compounds for use in the present invention are administered at an initial dose of 0.001 mg / kg to 10 mg / kg body weight per day. However, these doses can vary depending on the needs of the patient, the severity of the condition being treated, and the compound used. Generally, treatment is started at a lower dose that is less than the optimal dose of the compound, and thereafter, the dose is increased in small amounts to achieve the best effect. For convenience, the total daily dose can be further divided into several administrations within a day if necessary.

[0156] The pharmaceutical compositions of the present invention can also be used in combination with other drugs for treating pain, epilepsy, anxiety, and depression, including but not limited to morphine, gabapentin, etc. Therefore, the present invention provides a drug for treating pain, epilepsy, anxiety, and depression, which is not only effective but also has no obvious side effects. Another object of the present invention is to provide a drug with high safety for special patient groups, such as the elderly, patients with liver or kidney function decline, or patients with cardiovascular diseases.

[0157] The present invention also provides a method for treating or preventing a disease, which comprises administering an effective dose of the compound or composition as described above to a patient.

[0158] The present invention also provides a method for treating or preventing a disease related to the GABA A receptor, which comprises administering an effective dose of the compound as described above or the composition as described above to a patient.

[0159] The present invention also provides the use of the compound or composition as described above in the preparation of a drug for treating or preventing the following diseases: pain, Alzheimer's disease, multi-infarct dementia, and stroke.

[0160] The pain described above is neuropathic pain, inflammatory pain, and cancer pain. Preferably, the pain is selected from: headache, facial pain, neck pain, shoulder pain, back pain, chest pain, abdominal pain, dorsal pain, lumbar pain, lower limb pain, muscle and bone pain, vascular pain, gout, arthritis pain, visceral pain, pain caused by infectious diseases, polyostotic pain, sickle cell anemia, autoimmune diseases, multiple sclerosis, or pain related to inflammation, chronic pain caused by injury or surgery, nociceptive pain, painful diabetes, trigeminal neuralgia, lumbosacral or cervical radiculopathy, glossopharyngeal neuralgia, autonomic reflex pain, reflex sympathetic dystrophy, nerve root avulsion, cancer, chemical injury, toxins, nutritional deficiency, viral or bacterial infection, or pain related to degenerative osteoarthropathy.

[0161] The present invention also provides a method for treating or preventing pain, Alzheimer's disease, multi-infarct dementia, or stroke, by administering to a patient an effective dose of the compound as described above or the composition as described above.

[0162] Beneficial effects:

[0163] The compounds of the present invention, their pharmaceutically acceptable salts, or their prodrugs have important pharmacological properties and are positive allosteric modulators of the α2 / 3-GABA A receptor. The compounds of the present invention have excellent affinity activity and positive regulatory activity for the α2 / 3-GABA A receptor, and have good genotoxic safety and drugability. Therefore, the compounds of the present invention, their pharmaceutically acceptable salts, or their prodrugs can be used alone or in combination with other drugs for treating or preventing diseases related to α2 / 3-GABAA. Detailed implementation manners

[0164] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Among them, the solvent ratios used in the purification steps (such as preparative thin layer chromatography, column chromatography, etc.) in the following embodiments are volume ratios.

[0165] Example 1

[0166]

[0167] 1-2: (4-bromo-2-hydrazinopyridin-3-yl)methanol

[0168] 4-Bromo-2-fluoronicotinaldehyde (565 mg, 2.77 mmol) was added to tetrahydrofuran (3 ml), and sodium borohydride (63 mg, 1.67 mmol) was added to the reaction mixture. The mixture was stirred at room temperature for 20 minutes. The reaction mixture was quenched by pouring it into methanol (10 ml), then poured into water (30 ml), and extracted with dichloromethane (30 ml × 3 times). The organic phases were combined, dried over anhydrous sodium sulfate, concentrated, and a crude product as a colorless oily liquid (508 mg, 89%) was obtained. LC-MS: m / z [M+H] + = 206, 208.

[0169] 1-3: (7-bromo-3-cyclopropyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)methanol

[0170] (4-Bromo-2-fluoropyridin-3-yl)methanol (505 mg, 2.45 mmol) and hydrazine hydrate (246 mg, 4.9 mmol) were added to ethanol (4 ml), and the mixture was reacted at 95 °C for 2 hours. The reaction mixture was directly loaded onto a column for chromatography (dichloromethane / methanol = 10 / 1) to obtain the title compound as a white solid (388 mg, 51%). LC-MS: m / z [M+H] + = 218, 220.

[0171] 1-4: 7-bromo-3-cyclopropyl-8-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine

[0172] (4-Bromo-2-hydrazinopyridin-3-yl)methanol (150 mg, 0.48 mmol) and cyclopropylcarbaldehyde (50 mg, 0.72 mmol) were added to ethanol (2 ml), and the mixture was reacted at 90 °C for 1 hour. Potassium carbonate (66 mg, 0.66 mmol) and iodine (12 mg, 0.05 mmol) were added to the reaction mixture, and the mixture was stirred at room temperature for 4 hours. The reaction mixture was prepared for thin-layer chromatography (dichloromethane / methanol = 25 / 1) to obtain the title compound as a brown solid (65 mg, 51%). LC-MS: m / z [M+H] + = 268, 270.

[0173] Compound 1: 4-(3-(3-cyclopropyl-8-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridin-7-yl)-

[0174] (7-Bromo-3-cyclopropyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)methanol (60 mg, 0.22 mmol) was added to tetrahydrofuran (2 ml), and sodium hydride (8 mg, 0.26 mmol) was added to the reaction mixture. The mixture was stirred at room temperature for 10 minutes, and iodomethane (47 mg, 0.33 mmol) was added to the reaction mixture. The mixture was stirred at room temperature for 30 minutes. The reaction mixture was prepared for thin-layer chromatography (dichloromethane / methanol = 30 / 1) to obtain the title compound as a brown solid (55 mg, 89%). LC-MS: m / z [M+H] + = 282, 284.

[0175] 4-fluorophenyl)-7-ethyl-7H-imidazo[4,5-c]pyridazine2-1: 5-bromo-4-methoxypyridin-2-amine

[0176] 7-Bromo-3-cyclopropyl-8-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine (30 mg, 0.11 mmol), (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (31 mg, 0.11 mmol), sodium carbonate (23 mg, 0.22 mmol), and bis(triphenylphosphine)palladium(II) dichloride (8 mg, 0.01 mmol) were added to tetrahydrofuran (2 mL) and water (0.1 mL). Under argon protection, the reaction was carried out at 80 °C for 16 hours. The reaction mixture was prepared for thin-layer chromatography (dichloromethane / methanol = 15 / 1) to obtain the title compound as a brown solid (8 mg, 16%).

[0177] 1 H NMR (400 MHz, CHLOROFORM-d) 9.40 (s, 1H), 8.42 (d, J = 6.8 Hz, 2H), 8.28 (s, 1H), 8.16 - 8.10 (m, 1H), 7.46 - 7.38 (m, 1H), 6.93 (br.s., 1H), 4.83 (br.s., 2H), 4.59 (d, J = 7.3 Hz, 2H), 3.41 (s, 3H), 2.13 - 2.00 (m, 1H), 1.71 - 1.68 (m, 3H), 0.88 (br.s., 4H). LC-MS: m / z [M + H] + = 444.

[0178] Example 2

[0179]

[0180] 2-2: 6-bromo-2-(1-fluorocyclopropyl)-7-methoxyimidazo[1,2-a]pyridine

[0181] 2-Amino-4-methoxypyridine (5 g, 40 mmol) was dissolved in anhydrous acetonitrile (80.0 mL), and N-bromosuccinimide (NBS, 7 g, 40 mmol) was added portionwise. The mixture was stirred at 0 °C for 2 hours, quenched with saturated aqueous sodium bicarbonate solution (100 mL), and then separated. The organic layer was collected, and the aqueous phase was extracted with dichloromethane (100 mL × 3). After evaporation to dryness, the crude product was obtained and purified by normal-phase silica gel column chromatography (petroleum ether:ethyl acetate = 10:1 - 2:1) to obtain the title product (4 g, 58%) as a white solid. LC-MS: m / z [M + 1] + = 203

[0182] Compound 2: 7-isopropyl-4-(4-fluoro-3-(2-(1-fluorocyclopropyl)-7-methoxyimidazo[1,2-a]pyridin-

[0183] Dissolve 5-bromo-4-methoxypyridin-2-amine (500 mg, 2.5 mmol), 2-chloro-1-(1-fluorocyclopropyl)ethan-1-one (670 mg, 5 mmol), and cesium carbonate (1.6 g, 5 mmol) in ethanol (10.0 mL). Heat the solution to 100 °C in a microwave reactor and react for 1 hour. Purify the reaction solution by preparative HPLC to obtain the title product (100 mg, 27%) as a white solid. LC-MS: m / z [M+1] + = 285

[0184] 6-yl)phenyl)-7H-imidazo[4,5-c]pyridazine 3-1: 2-fluoro-4-iodo-3-methoxypyridine

[0185] Suspend 6-bromo-2-(1-fluorocyclopropyl)-7-methoxyimidazo[1,2-a]pyridine (100.0 mg, 0.36 mmol), (5-(7-isopropyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (105 mg, 0.36 mmol), cesium carbonate (210 mg, 0.54 mmol), and [1,1-bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II) (16.5 mg, 0.036 mmol) in a solution of 1,4-dioxane / water (5.5 mL, v / v = 10 / 1). Heat the solution to 100 °C and react for 2 hours. Dilute the reaction solution with ethyl acetate (50 mL), wash it with saturated aqueous sodium chloride solution (50 mL × 3), dry the organic phase, concentrate it, and then purify it by preparative HPLC to obtain the title product (30 mg, 17%) as a white solid.

[0186] 1 H NMR (400 MHz, CDCl3) 9.64 (s, 1H), 9.06 (s, 1H), 8.98 (s, 1H), 8.70–8.62 (m, 1H), 8.58 (dd, J = 7.0, 2.2 Hz, 1H), 8.25 (s, 1H), 7.65 (t, J = 9.2 Hz, 1H), 7.30 (s, 1H), 5.22–5.02 (m, 1H), 4.02 (s, 3H), 1.67 - 1.63 (m, 8H), 1.42 (q, J = 8.5 Hz, 2H). LC-MS: m / z [M+1] + = 461

[0187] Examples 3 and 4

[0188]

[0189] 3-2: 2-hydrazino-4-iodo-3-methoxypyridine

[0190] Dissolve 2-fluoro-3-methoxypyridine (5 g, 39.3 mmol) in anhydrous tetrahydrofuran (150 mL). Under nitrogen protection, cool the reaction solution to -60 °C, slowly add n-butyllithium (2.5 M) (23.6 mL, 59 mmol), control the temperature at -60 to -65 °C, which takes 10 min, and stir at -60 °C for 1 h. Slowly add an anhydrous tetrahydrofuran solution (100 mL) of iodine (11 g, 43 mmol), keep the temperature around -60 °C, which takes 2 h, then react at -60 °C for 2 h. Add saturated ammonium chloride aqueous solution (200 mL) to quench the reaction, extract with ethyl acetate (100 mL × 3), wash with saturated brine (100 mL), dry over anhydrous sodium sulfate, and after concentration, purify by normal phase (petroleum ether: ethyl acetate = 3:1) to obtain the title product (6.8 g, white solid) with a yield of 68%. 1 HNMR(400MHz,CDCl3)7.56(m,2H),3.99(s,3H).

[0191] 3-3: N'-(4-iodo-3-methoxypyridin-2-yl)-3-methoxycyclobutane-1-carbohydrazide

[0192] Dissolve 2-fluoro-4-iodo-3-methoxypyridine (6.8 g, 26.88 mmol) in ethanol (68.0 mL), add water and hydrazine (2.7 g, 53.8 mmol), and react at 90 °C for 16 h. After concentration, add water (100 mL), stir for 30 min, filter, and collect the filter cake. After vacuum drying, obtain the title product (5.5 g, white solid) with a yield of 78%. LCMS: m / z [M+1] + =266

[0193] 3-4: 7-iodo-8-methoxy-3-(3-methoxycyclobutyl)-[1,2,4]triazolo[4,3-a]pyridine

[0194] Dissolve 2-hydrazino-4-iodo-3-methoxypyridine (300 mg, 1.13 mmol), 3-methoxycyclobutane-1-carboxylic acid (147 mg, 1.13 mmol), and 2-(7-azabenzotriazol)-N,N,N',N'-tetramethyluronium hexafluorophosphate (472.6 mg, 1.24 mmol) in anhydrous dichloromethane (12 mL). Under nitrogen protection, slowly add diisopropylethylamine (366 mg, 2.83 mmol), and stir at 30 °C for 2 h. Pour the reaction solution into ice water, extract with dichloromethane (100 ml × 3), and after concentration, purify by reverse phase to obtain the title product (270 mg, yellow oil) with a yield of 71%. LCMS: m / z [M+1] + =378

[0195] Compound 3: rel-4

[0196] Dissolve N'-(4-iodo-3-methoxypyridin-2-yl)-3-methoxycyclobutane-1-carbohydrazide (270 mg, 0.72 mmol) in anhydrous tetrahydrofuran (10 ml), add Burgess reagent (N-(triethylammoniumsulfonyl) carbamic acid methyl ester, 512 mg, 2.15 mmol), and react this reaction under nitrogen protection at 60 °C for 3 h. Pour the reaction solution into water (50 ml). Extract with ethyl acetate (50 ml × 3), concentrate to obtain a crude product, and obtain the title product (170 mg, white solid) after purification by HPLC preparation, with a yield of 66%. LCMS: m / z [M+1] + = 360

[0197] (4-fluoro-3-(8-methoxy-3-((1s,3s)-3-methoxycyclobutyl)-[1,2,4]tri - azol[4,3-a]pyridin-7-yl)phenyl)-7-isopropyl-7H-imidazo[4,5-c]pyridazine Compound 4: rel-4-(4-fluoro-3-(8-methoxy-3-((1r,3r)-3-methoxycyclobutyl)-[1,2,4]tri

[0198] azol[4,3-a]pyridin-7-yl)phenyl)-7-isopropyl-7H-imidazo[4,5-c]pyridazine : 4-(methoxymethylene)-2-methyltetrahydro-2H-pyran

[0199] The experimental operation is the same as that in Example 2. Using 7-iodo-8-methoxy-3-(3-methoxycyclobutyl)-[1,2,4]triazolo[4,3-a]pyridine (100.0 mg, 0.278 mmol) and (2-fluoro-5-(7-isopropyl-7H-imidazo[4,5-c]pyridazin-4-yl)phenyl)boronic acid (100.3 mg, 0.334 mmol) as raw materials, a mixture of the two titles is obtained, with an appearance of a white solid. Then, chiral resolution is carried out to obtain Example 3 and Example 4. Resolution method: Instrument: MGⅡ preparative SFC (supercritical fluid preparative chromatograph, SFC-1); Chromatographic column: ChiralPak AD, 250×30 mm I.D., 10 μm; Mobile phase: A is CO2, B is isopropanol; B is 55 vt%; Flow rate: 80 mL / min; Back pressure: 100 bar; Column temperature: 38 °C; Wavelength: 220 nm.

[0200] Example 3: The first peak, 14 mg, white solid, yield 10%.

[0201] 11H NMR (400 MHz, DMSO-d6) δ 9.58 (s, 1H), 8.95 (s, 1H), 8.64–8.44 (m, 2H), 8.13 (d, 1H), 7.67–7.46 (m, 1H), 7.03 (d, 1H), 5.24–4.92 (m, 1H), 4.33 (d, J = 3.2 Hz, 3H), 4.22–3.88 (m, 2H), 3.21 (s, 3H), 2.72 (m, 2H), 2.59–2.49 (m, 2H), 1.68 (d, J = 6.8 Hz, 6H). LCMS: m / z [M+H] + = 488

[0202] Example 4: The second peak, 38 mg, white solid, yield 28%.

[0203] 1 1H NMR (400 MHz, DMSO-d6) δ 9.58 (s, 1H), 8.95 (s, 1H), 8.65–8.43 (m, 2H), 8.19 (d, 1H), 7.70–7.44 (m, 1H), 7.04 (d, 1H), 5.22–5.00 (m, 1H), 4.33 (s, 3H), 4.02 (t, J = 6.9 Hz, 1H), 3.60 (d, J = 7.9 Hz, 1H), 3.21 (s, 3H), 2.97–2.75 (m, 2H), 2.32 (dd, J = 10.5, 8.8 Hz, 2H), 1.68 (d, J = 6.8 Hz, 6H). LCMS: m / z [M+H] + = 488.

[0204] Example 5

[0205]

[0206] 5- 1 5-2: 2-methyltetrahydro-2H-pyran-4-carbaldehyde

[0207] (Methoxymethyl)triphenylphosphonium chloride (22 g, 64.4 mmol) was suspended in anhydrous tetrahydrofuran (180 mL), and the reaction mixture was cooled to -10 to -20 °C under nitrogen protection. Lithium bis(trimethylsilyl)amide (1 M, 64.3 mL, 64.4 mmol) was slowly added dropwise, controlling the temperature at -10 to -20 °C, which took 30 min, and then stirred at -10 to -20 °C for 2 h. A solution of 2-methyltetrahydro-4H-pyran-4-one (4.9 g, 42.9 mmol) in anhydrous tetrahydrofuran (50 mL) was added dropwise over 10 min, then the mixture was allowed to warm to room temperature and reacted for 16 h. The reaction was quenched by adding saturated ammonium chloride (200 mL), extracted with ethyl acetate (200 mL × 3), washed with saturated brine (200 mL), dried over anhydrous sodium sulfate, concentrated, and purified by normal-phase chromatography (petroleum ether:ethyl acetate = 10:1) to obtain the title product (4.9 g, yellow oil) with a yield of 80%. 1 H NMR (400 MHz, CDCl3) 5.95–5.76 (m, 1H), 4.07–3.95 (m, 1H), 3.54 (m, 3H), 3.43–3.26 (m, 2H), 2.62 (m, 1H), 2.01–1.78 (m, 2H), 1.70–1.55 (m, 1H), 1.20 (m, 3H).

[0208] 5-3: 7-iodo-8-methoxy-3-(2-methyltetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]py

[0209] 4-(Methoxymethylene)-2-methyltetrahydro-2H-pyran (4.9 g, 34.4 mmol) was dissolved in formic acid (59 mL), water (30 mL) was added, and the mixture was heated to 90 °C and reacted for 6 h. After cooling, water (300 mL) was added, stirred for 30 min, and the pH was adjusted to 8 - 9 with 6N NaOH. It was extracted with dichloromethane (150 ml × 3), washed with saturated brine (100 mL), dried over anhydrous sodium sulfate, concentrated, and purified by normal-phase chromatography (petroleum ether:ethyl acetate = 2:1) to obtain the title product (0.7 g, yellow oil) with a yield of 16%. 1 H NMR (400 MHz, CDCl3) 9.67 (s, 1H), 4.09 (m, 1H), 3.60–3.36 (m, 2H), 2.51 (m, 1H), 1.84 (m, 2H), 1.56 (m, 1H), 1.24 (d, J = 6.2 Hz, 3H), 1.22–1.14 (m, 1H).

[0210] ridine ​

[0211] Dissolve 2-methyltetrahydro-2H-pyran-4-carbaldehyde (400 mg, 1.51 mmol) and 2-hydrazino-4-iodo-3-methoxypyridine (193 mg, 1.51 mmol) in ethanol (8 ml), and heat this reaction to 90 °C under nitrogen protection for 2 h. Concentrate the reaction solution, dissolve it in dichloromethane (16 mL), add iodine (460 mg, 1.81 mmol) and potassium carbonate (625 mg, 4.53 mmol), and stir at room temperature for 16 h. Add water (100 mL), extract with dichloromethane (50 mL×3), wash with saturated sodium thiosulfate (50 mL), wash with saturated brine (50 mL), dry over anhydrous sodium sulfate, and after concentration, purify by reverse phase (0.5% HCOOH~CH3CN) to obtain the title product (241 mg, white solid) with a yield of 43%. LCMS: m / z [M+H] + = 374

[0212] Compound 5: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(2-methyltetrahydro-2H-pyran-4-yl)-[1,2, 4]triazolo[4,3-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0213] The experimental operation was the same as in Example 2. Using 7-iodo-8-methoxy-3-(2-methyltetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]pyridine (100 mg, 0.27 mmol) and (2-fluoro-5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)phenyl)boronic acid (77 mg, 0.27 mmol) as raw materials, the title compound (35 mg, white solid) was obtained with a yield of 27.0%.

[0214] 1 H NMR (400 MHz, DMSO-d6) 9.58 (s, 1H), 8.88 (s, 1H), 8.68–8.49 (m, 2H), 8.44 (d, 1H), 7.66–7.53 (m, 1H), 7.04 (d, 1H), 4.52 (q, 2H), 4.31 (s, 3H), 4.02 (m, 1H), 3.61 (m, 3H), 2.01 (m, 2H), 1.84 (m, 1H), 1.65–1.46 (m, 4H), 1.18 (d, 3H). LCMS: m / z [M+H] + = 488

[0215] Example 6

[0216]

[0217] Compound 6: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(3-methoxycyclobutyl)-[1,2,4]triazolo [4,3-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0218] The experimental operations were the same as those in Example 2. Using 7-iodo-8-methoxy-3-(3-methoxycyclobutyl)-[1,2,4]triazolo[4,3-a]pyridine (85 mg, 0.24 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (66 mg, 0.24 mmol) as raw materials, the title compound (41.0 mg, white solid) was obtained with a yield of 36.2%.

[0219] 1 H NMR (400 MHz, DMSO-d6) 9.58 (s, 1H), 8.88 (s, 1H), 8.63–8.46 (m, 2H), 8.18 (d, J = 7.0 Hz, 1H), 7.59 (t, J = 9.2 Hz, 1H), 7.03 (d, J = 7.0 Hz, 1H), 4.52 (q, J = 7.2 Hz, 2H), 4.32 (s, 3H), 4.02 (m, 1H), 3.61 (m, 1H), 3.21 (s, 3H), 2.87 (m, 2H), 2.31 (m, 2H), 1.56 (t, J = 7.3 Hz, 3H). LCMS: m / z [M+1] + = 474

[0220] Example 7

[0221]

[0222] 7-1: 4-Chloro-2-(chloromethyl)-3-methoxypyridine

[0223] 4-Chloro-3-methoxy-2-methylpyridine 1-oxide (4.9 g, 28.31 mmol) was dissolved in anhydrous dichloromethane (250 mL). Under nitrogen protection, phosphorus oxychloride (6.5 g, 42.47 mmol) dissolved in dichloromethane (40 mL) and triethylamine (5.7 g, 56.62 mmol) dissolved in dichloromethane (40 mL) were simultaneously and slowly added dropwise at the same rate. After addition, the mixture was stirred at 30 °C for 3 h. The reaction solution was poured into 300 mL of saturated sodium bicarbonate solution, extracted with dichloromethane (200 ml × 3), washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated to obtain the title product (4.9 g, yellow solid) with a yield of 89%. LCMS: m / z [M+1] + = 192

[0224] 7-2: 2–((4-Chloro-3-methoxypyridin-2-yl)methyl)isoindole-1,3-dione

[0225] Dissolve 4-chloro-2-(chloromethyl)-3-methoxypyridine (5.4 g, 28.31 mmol) and potassium phthalimide (5.2 g, 28.31 mmol) in N,N-dimethylformamide (100.0 mL), and carry out this reaction under nitrogen protection at 60 °C for 16 h. Pour the reaction solution into water (100 mL). Extract with ethyl acetate (100 mL × 3), wash with 5% lithium chloride and saturated brine respectively, dry over anhydrous sodium sulfate, concentrate to obtain a crude product, and obtain the title product (3.7 g, white solid) after normal-phase purification (CH2Cl2~ethyl acetate) with a yield of 48%. 1 1H NMR (400 MHz, CDCl3) δ 8.09 (d, J = 5.2 Hz, 1H), 7.91–7.85 (m, 2H), 7.78–7.71 (m, 2H), 7.21 (d, J = 5.2 Hz, 1H), 5.08 (s, 2H), 4.03 (s, 3H). LCMS: m / z [M+1] + = 303

[0226] 7-3: (4-Chloro-3-methoxypyridin-2-yl)methanamine

[0227] Dissolve 2–((4-chloro-3-methoxypyridin-2-yl)methyl)isoindoline-1,3-dione (3.8 g, 12.53 mmol) in ethanol (38 mL), add water and hydrazine (7.6 mL), and carry out this reaction at 80 °C for 16 h. After rotary evaporation of ethanol from the reaction solution, add 50 mL of water, adjust the pH = 1 with concentrated hydrochloric acid, a large amount of solid precipitates, filter, collect the filtrate, adjust the pH = 9–10 with NaOH, then extract with ethyl acetate (100 mL × 3), wash with saturated brine, dry over anhydrous sodium sulfate, and concentrate to obtain the title product (1.35 g, yellow oil) with a yield of 62%. LCMS: m / z [M+1] + = 173

[0228] 7-4: N-((4-Chloro-3-methoxypyridin-2-yl)methyl)tetrahydro-2H-pyran-4-carboxamide

[0229] Dissolve (4-chloro-3-methoxypyridin-2-yl)methanamine (300 mg, 1.74 mmol) in dichloromethane (6 mL), add diisopropylethylamine (562 mg, 4.35 mmol), then slowly add 4-hydroxypyran-4-carbonyl chloride (258.5 mg, 1.74 mmol) dropwise to the reaction solution, and carry out this reaction at 30 °C for 3 h. Pour the reaction solution into 50 mL of water, extract with dichloromethane (50 mL × 3), wash with saturated brine, dry over anhydrous sodium sulfate, and concentrate to obtain the title product (497 mg, yellow oil).

[0230] 7-5: 7-Chloro-8-methoxy-3-(tetrahydro-2H-pyran-4-yl)imidazo[1,5-a]pyridine

[0231] Dissolve N-((4-chloro-3-methoxypyridin-2-yl)methyl)tetrahydro-2H-pyran-4-carboxamide (200 mg, 0.7 mmol) in anhydrous tetrahydrofuran (4 ml), add Burgess reagent (502 mg, 2.1 mmol), and react this reaction at 60 °C for 3 h under N2 protection. Pour the reaction solution into water (50 mL). Extract with ethyl acetate (50 ml × 3), concentrate to obtain a crude product, and obtain the title product (102 mg, white solid) after reverse-phase purification (0.5% HCOOH~CH3CN) with a yield of 54%. LCMS: m / z [M+1] + = 267

[0232] 7: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(tetrahydro-2H-pyran-4-yl)imidazo[1,5-a]pyridin- 7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0233] The experimental operation is the same as that in Example 2. Using 7-chloro-8-methoxy-3-(tetrahydro-2H-pyran-4-yl)imidazo[1,5-a]pyridine (102.1 mg, 0.38 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (109.5 mg, 0.38 mmol) as raw materials, the title compound (22 mg, white solid) is obtained with a yield of 12%.

[0234] 1 H NMR (400 MHz, DMSO-d6) 9.57 (s, 1H), 8.87 (s, 1H), 8.56 (d, 1H), 8.52–8.38 (m, 1H), 8.19 (d, 1H), 7.61 (s, 1H), 7.55 (t, 1H), 6.71 (d, 1H), 4.52 (q, J = 7.2 Hz, 2H), 4.04–3.88 (m, 5H), 3.53 (m, 3H), 1.96–1.75 (m, 4H), 1.56 (t, J = 7.2 Hz, 3H). LCMS: m / z [M+1] + = 473

[0235] Example 8

[0236]

[0237] 8-1: 5-Amino-1-methyl-1H-pyrazole-4-carbaldehyde

[0238] 5-Amino-1-methyl-1H-pyrazole-4-carbonitrile (5 g, 128 mmol) was added to tetrahydrofuran (20 ml). Under argon protection, the temperature was lowered to -20 °C, and diisobutylaluminum hydride (40 mL, 40 mmol) was added dropwise. After addition, the mixture was stirred at room temperature for 16 hours. The reaction solution was poured into ice water (50 mL), filtered, and the filtrate was extracted with ethyl acetate (50 mL × 3), concentrated, and purified by column chromatography (dichloromethane:methanol = 15:1) to obtain a white solid compound (420 mg, yield 20%). LC-MS: m / z [M+H] + = 126.0

[0239] 8-2: Methyl 3-(5-amino-1-methyl-1H-pyrazol-4-yl)acrylate

[0240] 18-Crown-6 (2.9 g, 11.0 mmol) was dissolved in tetrahydrofuran (20 mL), and the temperature was lowered to -40 °C. Then methyl 2-(dimethoxyphosphoryl)acetate (420 mg, 2.2 mmol) and lithium bis(trimethylsilyl)amide (2.2 mL, 2.2 mmol) were added. 5-Amino-1-methyl-1H-pyrazole-4-carbaldehyde (275 mg, 2.2 mmol) was dissolved in tetrahydrofuran (10 ml) and added dropwise to the system. Then the mixture was stirred at room temperature for 16 hours. The reaction solution was poured into water (50 mL), extracted with ethyl acetate (50 mL × 3), concentrated, and purified by column chromatography (petroleum ether:ethyl acetate = 1:1) to obtain a white solid compound (200 mg, yield 50%) LC-MS: m / z [M+H] + = 182

[0241] 8-3: 1-Methyl-1H-pyrazolo[3,4-b]pyridin-6-ol

[0242] Methyl 3-(5-amino-1-methyl-1H-pyrazol-4-yl)acrylate (200 mg, 1.1 mmol) was dissolved in dilute hydrochloric acid (3 mol / L, 20 mL) and stirred at 100 °C for 4 hours. It was directly evaporated to dryness, then dissolved by heating with distilled water (5 mL), allowed to stand and cooled in the upper layer of the refrigerator, and a large amount of white flocculent precipitate was formed. After filtration, a white solid (150 mg, yield 91%) was obtained. LC-MS: m / z [M+H] + = 150

[0243] 8-4: 5-Bromo-1-methyl-1H-pyrazolo[3,4-b]pyridin-6-ol

[0244] 1-Methyl-1H-pyrazolo[3,4-b]pyridin-6-ol (150 mg, 1.0 mmol) was added to acetic acid (15 mL), and bromine (480 mg, 3.0 mmol) was added dropwise. After stirring at room temperature for 2 h, the reaction solution was directly evaporated to dryness. Deionized water (20 mL) was added, and a large amount of white solid precipitated. The solid was filtered to obtain a white solid (100 mg, yield 44%). LC-MS: m / z [M+H] + = 228

[0245] 8-5: 5-Bromo-6-methoxy-1-methyl-1H-pyrazolo[3,4-b]pyridine

[0246] 5-Bromo-1-methyl-1H-pyrazolo[3,4-b]pyridin-6-ol (114 mg, 0.5 mmol) was added to N,N-dimethylformamide (20 mL). Cesium carbonate (326 mg, 1.0 mmol) and methyl iodide (142 mg, 1.0 mmol) were added. The reaction was carried out at 60 °C for 2 h. The reaction solution was poured into ice water (50 mL), and extracted with ethyl acetate (50 mL × 3). The extract was concentrated and purified by column chromatography (petroleum ether:ethyl acetate = 8:1) to obtain a white solid compound (120 mg, yield 99%). LC-MS: m / z [M+H] + = 242

[0247] 8: 7-Ethyl-4-(4-fluoro-3-(6-methoxy-1-methyl-1H-pyrazolo[3,4-b]pyridin-5-yl)phenyl)- 7H-imidazo[4,5-c]pyridazine

[0248] The experimental procedure was the same as in Example 2, using 5-bromo-6-methoxy-1-methyl-1H-pyrazolo[3,4-b]pyridine (100 mg, 0.40 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (125 mg, 0.44 mmol) as starting materials to obtain a white solid (30 mg, yield: 20%).

[0249] 1 H NMR (400 MHz, CDCl3) 9.42 (s, 1H), 8.36 (s, 1H), 8.30 (s, 2H), 7.96 (s, 1H), 7.92 (s, 1H), 7.37 (t, 1H), 4.59 (d, J = 6.8 Hz, 2H), 4.11 (s, 3H), 4.06 (s, 3H), 1.70 (t, J = 6.4 Hz, 3H). LC-MS: m / z [M+H] + = 404

[0250] Example 9

[0251]

[0252] 9-1: Methyl 6-bromo-7-methoxyimidazo[1,2-a]pyridine-2-carboxylate

[0253] 5-Bromo-4-methoxypyridin-2-amine (1 g, 3.5 mmol) and methyl 3-bromo-2-oxopropanoate (762 mg, 4.2 mmol) were added to anhydrous ethanol (10 mL) in a sealed tube and stirred at 90 °C overnight. The reaction mixture was directly separated and purified on a preparative plate (petroleum ether / ethyl acetate = 3 / 1) to obtain the title compound (600 mg, 60%).

[0254] 9-2: 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-2-carboxylic acid

[0255] Methyl 6-bromo-7-methoxyimidazo[1,2-a]pyridine-2-carboxylate (400 mg, 1.4 mmol) and aqueous sodium hydroxide solution (2 M, 2 mL) were added to tetrahydrofuran (4 mL) and stirred at room temperature overnight. The reaction mixture was concentrated, and the aqueous phase was extracted with ethyl acetate three times. The organic phase was concentrated and separated and purified on a preparative plate (dichloromethane / methanol = 20 / 1) to obtain the title compound (300 mg, 79%).

[0256] 9-3: (6-Bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)(pyrrolidin-1-yl)methanone

[0257] 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-2-carboxylic acid (300 mg, 1.1 mmol), 1-hydroxybenzotriazole (234 mg, 1.1 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (95 mg, 0.5 mmol), N,N-diisopropylethylamine (425 mg, 3.3 mmol) and pyrrolidine (213 mg, 3.3 mmol) were added to N,N-dimethylformamide (6 mL) and stirred at 35 °C overnight. The reaction was directly separated and purified on a preparative plate (dichloromethane / methanol = 20 / 1) to obtain the title compound (60 mg, 17%).

[0258] 9: (6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxyimidazo [1,2-a]pyridin-2-yl)(pyrrolidin-1-yl)methanone

[0259] The experimental procedure was the same as in Example 2, using (6-Bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)(pyrrolidin-1- yl)methanone (60 mg, 0.19 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (72 mg, 0.19 mmol) as starting materials to obtain the title compound (50 mg, 54%).

[0260] 11H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H), 8.30 (br.s., 1H), 8.15 - 8.04 (m, 1H), 7.79 - 7.67 (m, 1H), 7.53 (br.s., 1H), 7.38 (br.s., 1H), 4.59 (d, J=6.8 Hz, 1H), 4.13 (br.s., 1H), 3.90 (br.s., 3H), 3.75 (br.s., 1H), 2.03 - 1.93 (m, 4H), 1.70 (d, J=7.3 Hz, 1H). LC-MS: m / z [M+H] + =486.

[0261] Example 10

[0262]

[0263] 10-1: 1-(Ethylsulfonyl)-1,2,3,4-tetrahydropyrido[2,3-b]pyrazine

[0264] Dissolve 1,2,3,4-tetrahydropyrido[2,3-b]pyrazine (500 mg, 3.7 mmol) in tetrahydrofuran (10 mL), add triethylamine (1.12 g, 11.1 mmol), then add ethylsulfonyl chloride (480 mg, 3.7 mmol). Stir at room temperature for 12 hours. After diluting with ethyl acetate (200 mL), wash with water (150 mL x 2), dry, concentrate, and purify by column chromatography (petroleum ether:ethyl acetate = 1:1) to obtain a yellow solid (300 mg, yield 35.7%). LC-MS: m / z [M+H] + =228.0

[0265] 10 : 4-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-1-(ethylsulfonyl)- 1,2,3,4-tetrahydropyrido[2,3-b]pyrazine

[0266] Add 1-(ethylsulfonyl)-1,2,3,4-tetrahydropyrido[2,3-b]pyrazine (200 mg, 0.88 mmol), 4-(3-chloro-4-fluorophenyl)-7-ethyl-7H-imidazo[4,5-c]pyridazine (364 mg, 1.32 mmol), potassium phosphate (374 mg, 1.76 mmol), tris(dibenzylideneacetone)dipalladium (80 mg, 0.09 mmol), and toluene (20 mL) to the reaction flask in sequence. Heat to 90 °C and react for 16 hours. Directly concentrate the reaction solution and purify by prep-HPLC (0.5% NH3.H2O ~ acetonitrile) to obtain a white solid (30 mg, yield 15%).

[0267] 11H NMR (400 MHz, CDCl3) δ 9.39 (s, 1H), 8.32 (m, 2H), 8.28–8.19 (m, 1H), 7.91 (d, J = 4.8 Hz, 1H), 7.85 (d, J = 8.0 Hz, 1H), 7.43–7.33 (m, 1H), 6.74 (m, 1H), 4.58 (q, J = 7.3 Hz, 2H), 4.14–4.00 (m, 2H), 4.00–3.90 (m, 2H), 3.18 (q, J = 7.4 Hz, 2H), 1.70 (t, J = 7.3 Hz, 3H), 1.44 (t, J = 7.4 Hz, 3H). LC-MS: m / z [M+H] + = 468

[0268] Example 11

[0269]

[0270] 11-1: 4-Bromo-2-nitropyridin-3-ol

[0271] Under an inert atmosphere of nitrogen, 4-bromopyridin-3-ol (3 g, 17.3 mmol) was added to 8 mL of concentrated sulfuric acid and stirred for 15 minutes. Fuming nitric acid (1.64 g, 26 mmol) was added dropwise at 0 °C and stirred overnight. The reaction mixture was poured into 10 g of ice and extracted with ethyl acetate (10 mL × 3). After evaporation, the crude product was obtained and purified by normal-phase silica gel column chromatography (petroleum ether:ethyl acetate = 10:1 to 1:1) to give the title product (2.19 g, yield 56%) as a yellow solid. LC-MS: m / z [M+H] + = 219

[0272] 11-2: 4-Bromo-3-methoxy-2-nitropyridine

[0273] 4-Bromo-2-nitropyridin-3-ol (2.19 g, 10 mmol) and potassium carbonate (1.39 g, 20 mmol) were dissolved in N,N-dimethylformamide (17.0 mL). Iodomethane (1.43 g, 20 mmol) was added dropwise and stirred at room temperature for 17 hours. After quenching with water (20 mL), the mixture was extracted with ethyl acetate (20 mL × 2). After evaporation, the crude product was obtained and purified by normal-phase silica gel column chromatography (petroleum ether:ethyl acetate = 10:1 to 2:1) to give the title product (0.65 g, yield 28%) as a white solid. LC-MS: m / z [M+H] + = 233

[0274] 11-3: 4-Bromo-3-methoxypyridin-2-amine

[0275] 4-Bromo-3-methoxy-2-nitropyridine (550 mg, 2.37 mmol) and ammonium chloride (628 mg, 11.85 mmol) were dissolved in ethanol:water = 1:1 (16.6 mL), heated to 60 °C, and iron powder (664 mg, 11.85 mmol) was added in portions. The reaction was continued with stirring at 60 °C for 2 h, filtered, and the filter cake was washed with methanol (10 mL x 3). The washings were combined and concentrated in vacuo. It was diluted with 5 mL of water, and the aqueous phase was extracted with ethyl acetate (10 mL x 3). After evaporation, the title product (514 mg, 100%) was obtained as a brown solid. LC-MS: m / z [M+H] + = 203

[0276] 11-4: 7-Bromo-8-methoxyimidazo[1,2-a]pyridine

[0277] 4-Bromo-3-methoxypyridin-2-amine (200 mg, 0.99 mmol), chloroacetaldehyde (295 mg, 40 wt%, 1.5 mmol), and sodium bicarbonate (159 mg, 1.5 mmol) were dissolved in ethanol (10.0 mL). The solution was heated to 90 °C in a microwave reactor and reacted for 1 h. The reaction solution was concentrated, diluted with 2 mL of water, and the aqueous phase was extracted with dichloromethane (2 mL x 3). The organic phases were combined, dried, and concentrated in vacuo to obtain the title product (290 mg, 100%) as a brown solid. LC-MS: m / z [M+H] + = 227

[0278] 11-5: 7-Bromo-3-iodo-8-methoxyimidazo[1,2-a]pyridine

[0279] 7-Bromo-8-methoxyimidazo[1,2-a]pyridine (400 mg, 1.28 mmol) was dissolved in N,N-dimethylformamide (7.5 mL), and N-iodosuccinimide (375 mg, 1.67 mmol) was added. The reaction was stirred at 100 °C for 1 h. After cooling to room temperature, it was diluted with 10 mL of water, and the aqueous phase was extracted with methyl tert-butyl ether (10 mL x 3). After evaporation, the title product (220 mg, 100%) was obtained as a brown solid. LC-MS: m / z [M+H] + = 353

[0280] 11-6: 7-Bromo-3-cyclopropyl-8-methoxyimidazo[1,2-a]pyridine

[0281] 7-Bromo-3-iodo-8-methoxyimidazo[1,2-a]pyridine (400 mg, 1.13 mmol), cyclopropylboronic acid (97 mg, 1.13 mmol), tetrakis(triphenylphosphine)palladium(0) (131 mg, 0.113 mmol), and potassium phosphate (481 mg, 2.27 mmol) were dissolved in dioxane:H2O = 10:1 (11 mL). The mixture was degassed with argon three times and then stirred at 95 °C for 17 h. After cooling to room temperature, the reaction mixture was purified by normal-phase silica gel column chromatography (petroleum ether:ethyl acetate = 10:1 to 1:1) to give the title compound (100 mg, 33%) as a yellow solid. LC-MS: m / z [M+H] + = 267

[0282] 11: 4-(3-(3-Cyclopropyl-8-methoxyimidazo[1,2-a]pyridin-7-yl)-4-fluorophenyl)-7-ethyl- 7H-imidazo[4,5-c]pyridazine

[0283] The experimental procedure was the same as in Example 2, using 7-bromo-3-cyclopropyl-8-methoxyimidazo[1,2-a]pyridine (100 mg, 0.37 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (107 mg, 0.37 mmol) as starting materials to give the title compound (60 mg, 37%) as an off-white solid.

[0284] 1 H NMR (400 MHz, CDCl3) 9.37 (s, 1H), 8.38–8.30 (m, 1H), 8.29–8.20 (m, 2H), 7.85 (d, 1H), 7.36 (dd, 2H), 6.78 (d, 1H), 4.58 (q, 2H), 4.24 (s, 3H), 2.12 (s, 1H), 1.69 (t, 3H), 0.97 (m, 4H). LC-MS: m / z [M+H] + = 429

[0285] Example 12

[0286]

[0287] 12: 7-Ethyl-4-(4-fluoro-3-(2-(1-fluorocyclopropyl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)phenyl)- 7H-imidazo[4,5-c]pyridazine

[0288] The experimental procedure was the same as in Example 2, using 6-bromo-2-(1-fluorocyclopropyl)-7-methoxyimidazo[1,2-a]pyridine (100.0 mg, 0.36 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (100 mg, 0.36 mmol) as starting materials to give the title product (30 mg, yield 17%) as a white solid.

[0289] 1 1H NMR (400 MHz, DMSO-d6) δ 9.38 (s, 1H), 8.29 (m, 3H), 8.05 (s, 1H), 7.55 (s, 1H), 7.37 (t, 1H), 6.99 (s, 1H), 4.59 (q, 2H), 3.85 (s, 3H), 1.70 (t, 3H), 1.56–1.33 (m, 4H). LC-MS: m / z [M+H] + = 447

[0290] Example 13

[0291]

[0292] 13-1: Methyl 3-bromo-1-methyl-1H-pyrrolo[3,2-b]pyridine-6-carboxylate

[0293] Methyl 3-bromo-1H-pyrrolo[3,2-b]pyridine-6-carboxylate (102 mg, 0.4 mmol) was dissolved in N,N-dimethylformamide (5 mL). Sodium cyanide (32 mg, 0.8 mmol) was added at 0 °C and stirred for 30 min, then iodomethane (65 mg, 0.6 mmol) was added. The mixture was stirred at room temperature for 16 h. The reaction mixture was poured into ice water (30 mL), extracted with ethyl acetate (50 mL × 3), the organic phases were combined, dried, concentrated, and purified by column chromatography (petroleum ether:ethyl acetate = 3:1) to obtain a white solid (100 mg, yield 92.9%). LC-MS: m / z [M+H] + = 269

[0294] 13-2: 3-Bromo-N,1-dimethyl-1H-pyrrolo[3,2-b]pyridine-6-carboxamide

[0295] Methyl 3-bromo-1-methyl-1H-pyrrolo[3,2-b]pyridine-6-carboxylate (110 mg, 0.41 mmol) was dissolved in an ethanol solution of methylamine (5 mL). The mixture was stirred at 80 °C for 16 h and then directly concentrated to obtain a white solid (80 mg, yield 73.1%). LC-MS: m / z [M+H] + = 268

[0296] 13: 3-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-N,1-dimethyl-1H- pyrrolo[3,2-b]pyridine-6-carboxamide

[0297] The experimental procedure was the same as in Example 2, using 3-bromo-N,1-dimethyl-1H-pyrrolo[3,2-b]pyridine-6-carboxamide (80 mg, 0.30 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (101 mg, 0.36 mmol) as starting materials to obtain the title compound (45.0 mg, white solid) with a yield of 35%.

[0298] 1 1H NMR (400 MHz, CDCl3) δ 9.59–9.42 (m, 1H), 9.41–9.25 (m, 1H), 8.99–8.88 (m, 1H), 8.30–8.18 (m, 2H), 8.13–8.03 (m, 1H), 8.00–7.92 (m, 1H), 7.35–7.28 (m, 1H), 4.64–4.45 (m, 2H), 4.02–3.89 (m, 3H), 3.15–2.92 (m, 3H), 1.69–1.60 (m, 3H). LC-MS: m / z [M+H] + = 430

[0299] Example 14

[0300]

[0301] 14-1: 7-Iodo-8-methoxy-3-(tetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]pyridine

[0302] The experimental procedure was the same as the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (100 mg, 0.38 mmol) and tetrahydro-2H-pyran-4-carbaldehyde (50 mg, 0.38 mmol) as starting materials, the white solid title compound (100 mg, 74%) was obtained. LC-MS: m / z [M+H] + = 360.

[0303] 14: 4-(4-Fluoro-3-(8-methoxy-3-(tetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]pyridin-7-yl)phenyl)-7-isopropyl-7H-imidazo[4,5-c]pyridazine 15: 4,4'-(4-Fluoro-1,3-phenylene)bis(7-ethyl-7H-imidazo[4,5-c]pyridazine)

[0304] The experimental procedure was the same as in Example 2. Using 4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7-isopropyl-7H-imidazo[4,5-c]pyridazine (45 mg, 0.11 mmol) and 7-iodo-8-methoxy-3-(tetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.14 mmol) as starting materials, the title compound (40 mg, 74.5%) was obtained.

[0305] 11H NMR (400 MHz, CHLOROFORM-d) δ 9.37 (s, 1H), 8.37 - 8.31 (m, 2H), 8.27 (dd, J = 3.2, 5.6 Hz, 1H), 7.74 (d, J = 6.8 Hz, 1H), 7.40 (t, J = 9.0 Hz, 1H), 6.90 (d, J = 6.8 Hz, 1H), 5.30 - 5.17 (m, 1H), 4.50 (s, 3H), 4.19 (d, J = 11.7 Hz, 2H), 3.67 (t, J = 10.5 Hz, 2H), 3.43 - 3.31 (m, 1H), 2.33 - 2.22 (m, 2H), 2.07 (d, J = 13.7 Hz, 2H), 1.77 (d, J = 6.8 Hz, 6H). LC-MS: m / z [M+H] + = 488.

[0306] Example 15

[0307]

[0308] 16-1: 3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-

[0309] The experimental procedure was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (100 mg, 0.3 mmol) and 4-chloro-7-ethyl-7H-imidazo[4,5-c]pyridazine (5 mg, 0.3 mmol) as starting materials, the white solid title compound (17 mg, 16%) was obtained.

[0310] 1 1H NMR (400 MHz, CHLOROFORM-d) δ 9.45 (br.s., 2H) 8.84 - 9.02 (m, 1H) 8.37 - 8.49 (m, 1H) 8.30 (br.s., 2H) 7.50 (br.s., 1H) 4.49 - 4.69 (m, 4H) 1.71 (q, J = 7.01 Hz, 6H). LC-MS: m / z [M+H] + = 389.

[0311] Example 16

[0312]

[0313] a]pyridine 16: 4-(3-(3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)-8-methoxy-[1,2,4]triazolo[4,3-

[0314] The experiment was conducted following the same procedure as in the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (300 mg, 1.132 mmol) and 2,2-dimethyltetrahydro-2H-pyran-4-carbaldehyde (161 mg, 1.132 mmol) as starting materials, the title compound was obtained as a brown solid (259 mg, 59%). LC-MS: m / z [M+H] + = 388.

[0315] a]pyridin-7-yl)-4-fluorophenyl)-7-ethyl-7H-imidazo[4,5-c]pyridazine 17-1: 3-Cyclobutyl-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0316] The experiment was conducted following the same procedure as in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (50 mg, 0.13 mmol) and 3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (59 mg, 0.15 mmol) as starting materials, the title compound was obtained as a yellow solid (34 mg, 53%).

[0317] 1 H NMR (400 MHz, CHLOROFORM-d) 9.35 (s, 1H), 8.32 (dd, J = 2.2, 7.1 Hz, 1H), 8.29 - 8.23 (m, 2H), 7.74 (d, J = 7.3 Hz, 1H), 7.37 (t, J = 9.0 Hz, 1H), 6.89 (d, J = 7.3 Hz, 1H), 4.57 (q, J = 7.3 Hz, 2H), 4.46 (s, 3H), 3.97 - 3.84 (m, 2H), 3.53 - 3.43 (m, 1H), 2.16 - 2.07 (m, 2H), 1.99 - 1.92 (m, 2H), 1.67 (t, J = 7.3 Hz, 3H), 1.39 (s, 3H), 1.32 (s, 3H). LC-MS: m / z [M+H] + = 502.

[0318] Example 17

[0319]

[0320] 17: 4-(3-(3-Cyclobutyl-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-7-yl)-4-fluorophenyl)-

[0321] The experiment was conducted following the synthesis method in 5-3 of Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (300 mg, 1.132 mmol) and cyclobutylcarboxaldehyde (95 mg, 1.132 mmol) as starting materials, the title compound was obtained as a brown solid (262 mg, 70%). LC-MS: m / z [M+H] + = 330.

[0322] 7-ethyl-7H-imidazo[4],5-c]pyridazine 18-1: 7-Iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

[0323] The experiment was conducted following the procedure of Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (60 mg, 0.152 mmol) and 3-cyclobutyl-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.152 mmol) as starting materials, the title compound was obtained as a yellow solid (34 mg, 50%).

[0324] 1 1H NMR (400 MHz, CHLOROFORM-d) δ = 9.37 (s, 1H), 8.35 - 8.31 (m, 1H), 8.30 - 8.23 (m, 2H), 7.58 (d, J = 6.8 Hz, 1H), 7.38 (t, J = 9.0 Hz, 1H), 6.85 (d, J = 7.3 Hz, 1H), 4.62 - 4.55 (m, 2H), 4.48 (s, 3H), 3.88 (quin, J = 8.4 Hz, 1H), 2.76 - 2.54 (m, 4H), 2.29 - 2.09 (m, 2H), 1.68 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 444.

[0325] Example 18

[0326]

[0327] 18-2: 7-Iodo-8-methoxy-2-methyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

[0328] 2-Hydrazino-4-iodo-3-methoxypyridine (450 mg, 1.698 mmol) and carbonyldiimidazole (550 mg, 3.400 mmol) were added to acetonitrile (4 ml), and the reaction was carried out at 85 °C for 2 hours. The reaction mixture was filtered by suction, and the solid obtained was washed with water and then filtered by suction to obtain the title compound (370 mg, 75%). LC-MS: m / z [M+H] + = 292.

[0329] 18: 7-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-8-methoxy-2-methyl-

[0330] 7-Iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one (60 mg, 0.206 mmol), iodomethane (32 mg, 0.227 mmol), and cesium carbonate (134 mg, 0.412 mmol) were added to acetonitrile (1 mL), and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was filtered by suction, concentrated, and purified by preparative thin-layer chromatography (petroleum ether / ethyl acetate = 1 / 1) to obtain the title compound as a white solid (39 mg, 62%). LC-MS: m / z [M+H] + = 306.

[0331] [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one ​

[0332] The experimental procedure was the same as in Example 2, using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (42 mg, 0.115 mmol) and 3-(4-fluoro-1-methylpiperidin-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (35 mg, 0.115 mmol) as starting materials to obtain the title compound as a yellow solid (13 mg, 27%).

[0333] 1 H NMR (400 MHz, CHLOROFORM-d) 9.36 (s, 1H), 8.32 - 8.25 (m, 3H), 7.62 (d, J = 6.8 Hz, 1H), 7.38 (t, J = 9.0 Hz, 1H), 6.56 (d, J = 6.8 Hz, 1H), 4.59 (q, J = 7.2 Hz, 2H), 4.14 (s, 3H), 3.73 (s, 3H), 1.69 (t, J = 7.1 Hz, 3H). LC-MS: m / z [M+H] + = 420.

[0334] Example 19

[0335]

[0336] 19: (7-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-6-methoxyimidazo [1,5-a]pyridin-3-yl)(morpholine)methanone

[0337] 7-Ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (60 mg, 0.15 mmol), (7-bromo-6-methoxyimidazo[1,5-a]pyridin-3-yl)(morpholine)methanone (50 mg, 0.15 mmol), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (CAS: 95464-05-4, 12 mg, 0.02 mmol) and cesium carbonate (200 mg, 0.3 mmol) were successively added to 5 mL of dioxane and 0.5 mL of water, and then stirred at 95 °C for 2 hours. The reaction mixture was filtered, concentrated, and purified by preparative TLC (dichloromethane:methanol = 20:1) to obtain the white solid title compound (24 mg, 33%).

[0338] 1 H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H) 9.06 (s, 1H) 8.29 (s, 3H) 7.51 - 7.65 (m, 2H) 7.37 (t, J = 8.80 Hz, 1H) 4.59 (q, J = 7.34 Hz, 4H) 3.89 (s, 3H) 3.84 (br.s., 6H) 1.70 (t, J = 7.34 Hz, 3H). LC-MS: m / z [M+H] + = 502.

[0339] Example 20

[0340]

[0341] 20-1: N-((4-Chloro-3-methoxypyridin-2-yl)methyl)cyclopropanecarboxamide

[0342] (4-Chloro-3-methoxypyridin-2-yl)methanamine (900 mg, 5.2 mmol) and potassium carbonate (2.2 g, 15.7 mmol) were dissolved in acetonitrile (20 mL), and cyclopropanecarbonyl chloride (816 mg, 7.8 mmol) was added under an ice-water bath. The mixture was stirred at room temperature for 2 h, and the reaction mixture was directly evaporated to dryness and separated by column chromatography (petroleum ether:ethyl acetate = 1:1) to obtain a yellow solid (300 mg, yield 24%). LC-MS: m / z [M+H] + = 241

[0343] 20-2: 7-Chloro-3-cyclopropyl-8-methoxyimidazo[1,5-a]pyridine

[0344] N-((4-chloro-3-methoxypyridin-2-yl)methyl)cyclopropanecarboxamide (200 mg, 0.83 mmol), Burgess reagent (500 mg, 2.1 mmol) and dichloromethane (5 mL) were added to a reaction flask. After stirring at room temperature for 2 hours, it was directly evaporated to dryness and purified by column chromatography (petroleum ether:ethyl acetate = 1:1) to obtain a yellow oily liquid (110 mg, yield 60%). LC-MS: m / z [M+H] + = 223

[0345] 20: 4-(3-(3-Cyclopropyl-8-methoxyimidazo[1,5-a]pyridin-7-yl)-4-fluorophenyl)-7-ethyl- 7H-imidazo[4,5-c]pyridazine

[0346] 7-Chloro-3-cyclopropyl-8-methoxyimidazo[1,5-a]pyridine (50 mg, 0.23 mmol), 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (97 mg, 0.34 mmol), [1,1-bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II) (15 mg, 0.023 mmol), and cesium carbonate (150 mg, 0.46 mmol) were added to 1,4-dioxane / water (5 ml / 1 ml). Under argon protection, microwave reaction was carried out at 100 °C for 2 hours. After filtration, the filtrate was evaporated to dryness and sent for HPLC preparation. After lyophilization, the title product was obtained (26 mg, yield 27%).

[0347] 1 H NMR (400 MHz, DMSO-d6) 9.57 (s, 1H), 8.87 (s, 1H), 8.57 (dd, J = 7.2, 2.3 Hz, 1H), 8.52–8.36 (m, 1H), 8.20 (d, J = 7.2 Hz, 1H), 7.62–7.45 (m, 2H), 6.74 (d, J = 7.2 Hz, 1H), 4.52 (q, J = 7.2 Hz, 2H), 3.95 (s, 3H), 2.41–2.30 (m, 1H), 1.56 (t, J = 7.3 Hz, 3H), 1.15–1.03 (m, 2H), 1.00–0.84 (m, 2H). LC-MS: m / z [M+H] + = 429

[0348] Example 21

[0349]

[0350] 7-Chloro-6-methoxy-2-methylimidazo[1,2-a]pyridine

[0351] 4-Chloro-5-methoxypyridin-2-amine (20 mg, 0.13 mmol) was added to ethanol (2 mL), and chloroacetone (35 mg, 0.38 mmol) and sodium carbonate (40 mg, 0.38 mmol) were added. The mixture was heated to 100 °C by microwave irradiation and reacted for 1 h. After filtration and concentration, the title product was purified by column chromatography (5 mg, yield 20%). LC-MS: m / z [M+H] + = 197

[0352] 7-Ethyl-4-(4-fluoro-3-(6-methoxy-2-methylimidazo[1,2-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0353] 7-Chloro-6-methoxy-2-methylimidazo[1,2-a]pyridine (72 mg, 0.367 mmol), (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (105 mg, 0.367 mmol), [1,1-bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II) (24 mg, 0.0367 mmol), and cesium carbonate (239 mg, 0.735 mmol) were added to 1,4-dioxane / water (7.2 mL / 0.8 mL). Under argon protection, the mixture was reacted at 95 °C for 2 h. 10 mL of water was added, and the mixture was extracted with ethyl acetate (20 mL×2). The organic phase was dried over anhydrous sodium sulfate, concentrated, and purified by prep-HPLC (0.5% NH3·H2O~acetonitrile) to obtain a white solid (40 mg, yield: 31%).

[0354] 1 H NMR (400 MHz, CDCl3) 9.38 (s, 1H), 8.40–8.16 (m, 3H), 7.71 (s, 2H), 7.43–7.29 (m, 2H), 4.58 (q, J = 7.3 Hz, 2H), 3.84 (s, 3H), 2.51 (s, 3H), 1.69 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 403.

[0355] Example 22

[0356]

[0357] 22-1: 3-(4-Fluoropiperidin-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0358] 2-Hydrazino-4-iodo-3-methoxypyridine (300 mg, 0.822 mmol), tert-butyl 4-fluoro-4-formylpiperidine-1-carboxylate (285 mg, 1.233 mmol) were added to ethanol (2 ml), and the mixture was stirred at 25 °C for 2 h. Copper(II) bromide (37 mg, 0.164 mmol), potassium peroxymonosulfate (606 mg, 0.986 mmol) were added to the reaction mixture, and the mixture was stirred at 25 °C for 1.5 h. The reaction mixture was filtered by suction, concentrated, dissolved in dichloromethane (5 ml), and hydrochloric acid-ethyl acetate solution (4 mol / L, 2 ml) was added to the reaction mixture, and the mixture was stirred at 25 °C for 1 h. The reaction mixture was concentrated and evaporated to dryness, and the title compound as a yellow solid (179 mg, 61%) was obtained by preparative thin-layer chromatography (dichloromethane / methanol = 15 / 1). LC-MS: m / z [M+H] + = 377.

[0359] 22-2: 3-(4-Fluoro-1-methylpiperidin-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0360] 3-(4-Fluoropiperidin-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (179 mg, 0.500 mmol), aqueous formaldehyde solution (60 mg, 1 mmol) were added to tetrahydrofuran (1 ml), and the mixture was stirred at 25 °C for 5 min. Sodium cyanoborohydride (63 mg, 1 mmol) was added to the reaction mixture, and the mixture was stirred at 25 °C for 1 h. The reaction mixture was filtered by suction, concentrated, and the title compound as a brown solid (79 mg, 42%) was obtained by preparative thin-layer chromatography (dichloromethane / methanol = 20 / 1). LC-MS: m / z [M+H] + = 391.

[0361] 22: 7-Ethyl-4-(4-fluoro-3-(3-(4-fluoro-1-methylpiperidin-4-yl)-8-methoxy-[1,2,4]triazolo [4,3-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0362] The experimental procedure was the same as in Example 2, using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (71 mg, 0.195 mmol), 3-(4-fluoro-1-methylpiperidin-4-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (76 mg, 0.195 mmol) as starting materials, and the title compound as a pale yellow solid (6 mg, 6%) was obtained.

[0363] 11H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H), 8.36 (d, J = 6.8 Hz, 1H), 8.28 (s, 2H), 8.15 (d, J = 6.8 Hz, 1H), 7.41 (t, J = 9.0 Hz, 1H), 6.93 (d, J = 7.3 Hz, 1H), 4.59 (q, J = 7.3 Hz, 2H), 4.48 (s, 3H), 3.04 (br.s., 2H), 2.88 - 2.57 (m, 6H), 2.53 (s, 3H), 1.70 (br.s., 3H). LC-MS: m / z [M+H] + = 505.

[0364] Example 23

[0365]

[0366] 23-1: 3-(Azetidin-3-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0367] The experimental operation was the same as that in the synthesis method of 22-1 in Example 22. Using 2-hydrazino-4-iodo-3-methoxypyridine (250 mg, 0.94 mmol) and tert-butyl 3-formylazetidine-1-carboxylate (349 mg, 1.89 mmol) as raw materials, the title compound was obtained as a brown solid (136 mg, 44%). LC-MS: m / z [M+H] + = 331.

[0368] 23-2: 7-Iodo-8-methoxy-3-(1-(2,2,2-trifluoroethyl)azetidin-3-yl)-[1,2,4]triazolo [4,3-a]pyridine

[0369] 3-(Azetidin-3-yl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (136 mg, 0.41 mmol), 2,2,2-trifluoroethyl trifluoromethanesulfonate (113 mg, 0.50 mmol), and potassium carbonate (114 mg, 0.82 mmol) were added to acetonitrile (3 ml), and the reaction was carried out at 50 °C for 2 hours. The reaction solution was filtered by suction, concentrated, and purified by preparative thin-layer chromatography (dichloromethane / methanol = 30 / 1) to obtain the title compound as a yellow gummy solid (70 mg, 41%). LC-MS: m / z [M+H] + = 413.

[0370] 23: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(1-(2,2,2-trifluoroethyl)azetidin-3-yl)- [1,2,4]triazolo[4,3-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0371] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (62 mg, 0.17 mmol) and 7-iodo-8-methoxy-3-(1-(2,2,2-trifluoroethyl)azetidin-3-yl)-[1,2,4]triazolo[4,3-a]pyridine (70 mg, 0.17 mmol) as raw materials, the title compound was obtained as a pale yellow solid (22 mg, 25%).

[0372] 1 H NMR (400 MHz, CHLOROFORM-d) 9.36 (s, 1H), 8.34 (d, J = 5.9 Hz, 1H), 8.28 (s, 2H), 7.98 (d, J = 6.8 Hz, 1H), 7.39 (t, J = 9.0 Hz, 1H), 6.93 (d, J = 6.8 Hz, 1H), 4.58 (q, J = 7.3 Hz, 2H), 4.46 (s, 3H), 4.27 (quin, J = 7.5 Hz, 1H), 4.09 (t, J = 7.6 Hz, 2H), 3.88 (t, J = 7.1 Hz, 2H), 3.17 (q, J = 9.3 Hz, 2H), 1.68 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 527.

[0373] Example 24

[0374]

[0375] 24-1: 7-Iodo-8-methoxy-3-(4-methyltetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]py ridine

[0376] The experimental operation was the same as the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (100 mg, 0.38 mmol) and 4-methyltetrahydro-2H-pyran-4-carbaldehyde (96 mg, 0.75 mmol) as raw materials, the title compound was obtained as a brown-red solid (113 mg, 80%). LC-MS: m / z [M+H] + = 374.

[0377] 24: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(4-methyltetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo [4,3-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0378] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (54 mg, 0.15 mmol) and 7-iodo-8-methoxy-3-(4-methyltetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]pyridine (55 mg, 0.15 mmol) as raw materials, the titled compound was obtained as a yellow solid (19 mg, 27%).

[0379] 1 H NMR(400MHz,CHLOROFORM-d)9.38(s,1H),8.35(d,J=5.9Hz,1H),8.28(s,2H),7.94(d,J=7.3Hz,1H),7.40(t,J=9.0Hz,1H),6.87(d,J=6.8Hz,1H),4.59(q,J=7.3Hz,2H),4.49(s,3H),3.93-3.85(m,2H),3.83-3.73(m,2H),2.60(d,J=14.2Hz,2H),2.00-1.91(m,2H),1.69(br.s.,3H),1.59(s,3H).LC-MS:m / z[M+H] + =488.

[0380] Example 25

[0381]

[0382] 25-1: 3-(4,4-Difluorocyclohexyl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0383] The experimental operation was the same as the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (100 mg, 0.38 mmol) and 4,4-difluorocyclohexane-1-carbaldehyde (112 mg, 0.75 mmol) as raw materials, the titled compound was obtained as a brown-red solid (100 mg, 67%). LC-MS: m / z [M+H] + =394.

[0384] 25: 4-(3-(3-(4,4-Difluorocyclohexyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-7-yl)- 4-fluorophenyl)-7-ethyl-7H-imidazo[4,5-c]pyridazine

[0385] The experimental procedure was the same as in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (52 mg, 0.14 mmol) and 3-(4,4-difluorocyclohexyl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (55 mg, 0.14 mmol) as starting materials, the title compound was obtained as a pale yellow solid (13 mg, 20%).

[0386] 1 H NMR (400 MHz, CHLOROFORM-d) 9.38 (br.s., 1H), 8.34 (dd, J = 2.0, 6.8 Hz, 1H), 8.30 - 8.25 (m, 2H), 7.71 (d, J = 6.8 Hz, 1H), 7.39 (t, J = 9.0 Hz, 1H), 6.92 (d, J = 7.3 Hz, 1H), 4.61 - 4.56 (m, 2H), 4.49 (s, 3H), 3.25 (br.s., 1H), 2.39 (d, J = 9.3 Hz, 2H), 2.29 - 2.20 (m, 4H), 1.88 - 1.78 (m, 2H), 1.69 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 508.

[0387] Example 26

[0388]

[0389] 26-1: 6-Bromo-7-methoxy-2-methylimidazo[1,2-a]pyridine

[0390] 5-Bromo-4-methoxypyridin-2-amine (200 mg, 1 mmol) and bromoacetone (274 mg, 2 mmol) were added to anhydrous EtOH (5 mL) and stirred at 90 °C overnight. After concentrating the reaction mixture, it was purified by preparative thin-layer chromatography (petroleum ether / ethyl acetate = 1 / 1) to obtain the title compound (120 mg, 50%).

[0391] 26: 4-(4-Fluoro-3-(7-methoxy-2-methylimidazo[1,2-a]pyridin-6-yl)phenyl)-7-isopropyl- 7H-imidazo[4,5-c]pyridazine

[0392] The experimental procedure was the same as in Example 2. Using 6-bromo-7-methoxy-2-methylimidazo[1,2-a]pyridine (24.2 mg, 0.1 mmol) and 7-isopropyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (40 mg, 0.1 mmol) as starting materials, the title compound was obtained (17 mg, 42%).

[0393] 1 1H NMR (400 MHz, DMSO-d6) δ 9.55 - 9.51 (s, 1H), 8.93 - 8.89 (s, 1H), 8.64 - 8.41 (m, 4H), 7.60 - 7.49 (m, 2H), 5.12 - 5.06 (m, 1H), 3.87 - 3.78 (m, 3H), 2.39 - 2.24 (m, 3H), 1.66 (d, J = 6.8 Hz, 6H). LC-MS: m / z [M+H] + = 417.

[0394] Example 27

[0395]

[0396] 27-1: N'-(4-Iodo-3-methoxypyridin-2-yl)cyclopropanecarbohydrazide

[0397] The experimental operation was the same as the synthesis method of 3-3 in Example 3. Using 2-hydrazino-4-iodo-3-methoxypyridine (200 mg, 0.76 mmol) and cyclopropanecarboxylic acid (65 mg, 0.76 mmol) as raw materials, the title product (190.1 mg, white solid) was obtained with a yield of 76%. LC-MS: m / z [M+H] + = 334

[0398] 27-2: 3-Cyclopropyl-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0399] The experimental operation was the same as the synthesis method of 3-4 in Example 3. Using N'-(4-iodo-3-methoxypyridin-2-yl)cyclopropanecarbohydrazide (150.0 mg, 0.45 mmol) as the raw material, the title product (60.1 mg, white solid) was obtained with a yield of 32%. LC-MS: m / z [M+H] + = 316

[0400] 27: 4-(3-(3-Cyclopropyl-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-7-yl)-4-fluorophenyl)- 7-isopropyl-7H-imidazo[4,5-c]pyridazine

[0401] The experimental operation was the same as in Example 2. Using 3-cyclopropyl-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (100.0 mg, 0.32 mmol) and (2-fluoro-5-(7-isopropyl-7H-imidazo[4,5-c]pyridazin-4-yl)phenyl)boronic acid (142.8 mg, 0.48 mmol) as raw materials, the title compound (62.1 mg, white solid) was obtained with a yield of 37%.

[0402] 11H NMR (400 MHz, DMSO-d6) δ 9.57 (s, 1H), 8.94 (s, 1H), 8.65–8.48 (m, 2H), 8.40 (d, J = 7.0 Hz, 1H), 7.59 (t, J = 9.2 Hz, 1H), 7.07 (d, J = 7.0 Hz, 1H), 5.13 (m, 1H), 4.31 (s, 3H), 2.44 (m, 1H), 1.68 (d, J = 6.7 Hz, 6H), 1.27–0.98 (m, 4H). LC-MS: m / z [M+H] + = 444

[0403] Example 28

[0404]

[0405] 28-1: 7-Iodo-8-methoxy-3-(oxetan-3-yl)-[1,2,4]triazolo[4,3-a]pyridine

[0406] The experimental procedure was the same as that in the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (200 mg, 0.754 mmol) and oxetan-3-carbaldehyde (207 mg, 3.77 mmol) as starting materials, the title compound was obtained as a brown solid (151 mg, 61%). LC-MS: m / z [M+H] + = 332.

[0407] 28: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(oxetan-3-yl)-[1,2,4]triazolo[4,3- a]pyridin-7-yl ) phenyl)-7H-imidazo[4,5-c]pyridazine

[0408] The experimental procedure was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (56 mg, 0.151 mmol) and 7-iodo-8-methoxy-3-(oxetan-3-yl)-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.151 mmol) as starting materials, the title compound was obtained as a yellow solid (26 mg, 39%).

[0409] 11H NMR (400 MHz, CHLOROFORM-d) δ = 9.38 (br.s., 1H), 8.39 - 8.24 (m, 3H), 7.92 - 7.85 (m, 1H), 7.40 (t, J = 9.3 Hz, 1H), 6.96 (d, J = 4.9 Hz, 1H), 5.22 (d, J = 7.3 Hz, 4H), 4.79 (br.s., 1H), 4.63 - 4.55 (m, 2H), 4.49 (d, J = 2.9 Hz, 3H), 1.69 (br.s., 3H). LC-MS: m / z [M+H] + = 446.

[0410] Example 29

[0411]

[0412] 29-1: 7-Iodo-8-methoxy-3-isopropyl-[1,2,4]triazolo[4,3-a]pyridine

[0413] The experimental operation was the same as the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (200 mg, 0.754 mmol) and isobutyraldehyde (271 mg, 3.77 mmol) as raw materials, the title compound was obtained as a brown solid (109 mg, 46%). LC-MS: m / z [M+H] + = 318.

[0414] 29: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-isopropyl-[1,2,4]triazolo[4,3-a]pyridin-7-yl) phenyl)-7H-imidazo[4,5-c]pyridazine

[0415] The experimental operation was the same as in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (58 mg, 0.158 mmol) and 7-iodo-8-methoxy-3-isopropyl-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.158 mmol) as raw materials, the title compound was obtained as a yellow solid (17 mg, 25%).

[0416] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.38 (br.s., 1H), 8.37 - 8.23 (m, 3H), 7.72 (d, J = 6.4 Hz, 1H), 7.43 - 7.35 (m, 1H), 6.89 (d, J = 6.8 Hz, 1H), 4.59 (d, J = 7.3 Hz, 2H), 4.48 (br.s., 3H), 3.39 (d, J = 5.9 Hz, 1H), 1.70 (d, J = 7.8 Hz, 3H), 1.57 (d, J = 5.9 Hz, 6H). LC-MS: m / z [M+H]+ = 432.

[0417] Example 30

[0418]

[0419] 30-1: 6-Bromo-2-ethyl-7-methoxyimidazo[1,2-a]pyridine

[0420] 5-Bromo-4-methoxypyridin-2-amine (200 mg, 0.99 mmol) and bromobutanone (747 mg, 4.95 mmol) were successively added to anhydrous ethanol (5 mL), and the mixture was stirred at 90 °C for 16 hours. The reaction solution was concentrated, and the oily liquid title compound (150 mg, 60%) was obtained by separation using preparative thin-layer chromatography (petroleum ether / acetone = 4 / 1). LC-MS: m / z [M+H] + = 255, 257.

[0421] 30: 7-Ethyl-4-(3-(2-ethyl-7-methoxyimidazo[1,2-a]pyridin-6-yl)-4-fluorophenyl)-7H- imidazo[4,5-c]pyridazine

[0422] The experimental procedure was the same as in Example 2, using 6-bromo-2-ethyl-7-methoxyimidazo[1,2-a]pyridine (50 mg, 0.20 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (74 mg, 0.20 mmol) as starting materials, to obtain the brown solid title compound (10 mg, 12%).

[0423] 1 H NMR (400 MHz, CHLOROFORM-d) 9.37 (s, 1H), 8.28 (br.s., 3H), 8.02 (br.s., 1H), 7.36 (t, J = 8.8 Hz, 1H), 7.21 (br.s., 1H), 7.05 (br.s., 1H), 4.62 - 4.55 (m, 2H), 3.87 (br.s., 3H), 2.82 (d, J = 7.8 Hz, 2H), 1.69 (t, J = 7.1 Hz, 3H), 1.34 (d, J = 10.3 Hz, 3H). LC-MS: m / z [M+H] + = 417.

[0424] Example 31

[0425]

[0426] 31-1: 7-Iodo-8-methoxy-3-ethyl-[1,2,4]triazolo[4,3-a]pyridine

[0427] The experimental procedure was the same as that in the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (200 mg, 0.75 mmol) and propionaldehyde (219 mg, 3.77 mmol) as starting materials, the title compound was obtained as a brown solid (147 mg, 64%). LC-MS: m / z [M+H] + = 304.

[0428] 31: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-ethyl-[1,2,4]triazolo[4,3-a]pyridin-7-yl)benz yl)-7H-imidazo[4,5-c]pyridazine

[0429] The experimental procedure was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (60 mg, 0.165 mmol) and 7-iodo-8-methoxy-3-ethyl-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.165 mmol) as starting materials, the title compound was obtained as a yellow solid (23 mg, 33%).

[0430] 1 H NMR (400 MHz, CHLOROFORM-d) 9.37 (br.s., 1H), 8.38 - 8.22 (m, 3H), 7.68 (d, J = 4.4 Hz, 1H), 7.38 (t, J = 9.0 Hz, 1H), 6.89 (d, J = 5.9 Hz, 1H), 4.58 (d, J = 7.3 Hz, 2H), 4.46 (br.s., 3H), 3.13 (d, J = 7.3 Hz, 2H), 1.72 - 1.66 (m, 3H), 1.56 - 1.51 (m, 3H). LC-MS: m / z [M+H] + = 418.

[0431] Example 32

[0432]

[0433] 32-1: 7-Iodo-8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridine

[0434] The experimental procedure was the same as that in the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (200 mg, 0.75 mmol) and acetaldehyde - tetrahydrofuran solution (0.75 ml, 3.77 mmol) as starting materials, the title compound was obtained as a brown solid (140 mg, 64%). LC-MS: m / z [M+H] + = 290.

[0435] 32: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-7-yl)benz yl)-7H-imidazo[4,5-c]pyridazine

[0436] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (67 mg, 0.182 mmol) and 7-iodo-8-methoxy-3-methyl-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.182 mmol) as raw materials, the title compound was obtained as a yellow solid (27 mg, 37%).

[0437] 1 H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H), 8.34 (d, J = 6.4 Hz, 1H), 8.28 (s, 2H), 7.66 (d, J = 6.8 Hz, 1H), 7.39 (t, J = 9.0 Hz, 1H), 6.91 (d, J = 6.8 Hz, 1H), 4.58 (q, J = 7.0 Hz, 2H), 4.47 (s, 3H), 2.79 (s, 3H), 1.69 (br.s., 3H). LC-MS: m / z [M+H] + = 404.

[0438] Example 33

[0439]

[0440] 33-1: 7-Iodo-8-methoxy-3-(tetrahydrofuran-3-yl)-[1,2,4]triazolo[4,3-a]pyridine

[0441] The experimental operation was the same as the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (100 mg, 0.38 mmol) and tetrahydrofuran-3-carbaldehyde (50 mg, 0.38 mmol) as raw materials, the title compound was obtained as a white solid (140 mg, 100%). LC-MS: m / z [M+H] + = 346.

[0442] 33: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(tetrahydrofuran-3-yl)-[1,2,4]triazolo[4,3-a] pyridin-7-yl ) phenyl)-7H-imidazo[4,5-c]pyridazine

[0443] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (60 mg, 0.17 mmol) and 7-iodo-8-methoxy-3-(tetrahydrofuran-3-yl)-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.17 mmol) as raw materials, the title compound was obtained as a yellow solid (47 mg, 60%).

[0444] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.39 (s, 1H) 8.35 (d, J = 6.36 Hz, 1H) 8.29 (s, 2H) 7.83 (d, J = 6.85 Hz, 1H) 7.38 - 7.43 (m, 1H) 6.93 (d, J = 6.85 Hz, 1H) 4.59 (q, J = 6.85 Hz, 2H) 4.49 (s, 3H) 4.30 (d, J = 8.31 Hz, 1H) 4.23 (dd, J = 15.41, 7.09 Hz, 2H) 3.91 - 4.08 (m, 2H) 2.53 (d, J = 6.85 Hz, 2H) 1.69 - 1.72 (m, 3H). LC-MS: m / z [M+H] + = 460.

[0445] Example 34

[0446]

[0447] 34: 7-Ethyl-4-(4-fluoro-3-(8-methoxy-3-(tetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4, 3-a]pyridin-7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0448] The experimental procedure was the same as that of Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (70 mg, 0.2 mmol) and 7-iodo-8-methoxy-3-(tetrahydro-2H-pyran-4-yl)-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.2 mmol) as starting materials, the brown solid title compound (47 mg, 50%) was obtained.

[0449] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.39 (s, 1H) 8.35 (d, J = 5.87 Hz, 1H) 8.29 (s, 2H) 7.75 (d, J = 6.85 Hz, 1H) 7.40 (t, J = 9.05 Hz, 1H) 6.91 (d, J = 6.85 Hz, 1H) 4.59 (q, J = 7.34 Hz, 2H) 4.50 (s, 3H) 4.19 (d, J = 11.25 Hz, 2H) 3.67 (t, J = 11.00 Hz, 2H) 3.37 (t, J = 11.00 Hz, 1H) 2.20 - 2.35 (m, 2H) 2.08 (d, J = 13.21 Hz, 2H) 1.68 (br.s., 3H). LC-MS: m / z [M+H] + = 474.

[0450] Example 35

[0451]

[0452] 35-1: 3-(Difluoromethyl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0453] Dissolve 2-hydrazino-4-iodo-3-methoxypyridine (160 mg, 0.57 mmol) in 2 mL of difluoroacetic anhydride, and reflux it overnight. Dilute it with water, neutralize it to neutral with sodium bicarbonate solution, extract it with dichloromethane, concentrate it, and purify it by preparative plate (petroleum ether:ethyl acetate = 1:1) to obtain the white solid title compound (150 mg, 82%). LC-MS: m / z [M+H] + = 326.

[0454] 35 : 4-(3-(3-(Difluoromethyl)-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-7-yl)-4-fluoroben yl)-7-ethyl-7H-imidazo[4,5-c]pyridazine

[0455] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (80 mg, 0.22 mmol) and 3-(difluoromethyl)-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (75 mg, 0.22 mmol) as raw materials, the white solid title compound (39 mg, 41%) was obtained.

[0456] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H) 8.38 (d, J = 6.85 Hz, 1H) 8.29 (s, 2H) 8.18 (d, J = 6.85 Hz, 1H) 7.42 (t, J = 9.05 Hz, 1H) 7.30 (br.s., 1H) 7.08 (d, J = 6.85 Hz, 1H) 4.59 (q, J = 7.17 Hz, 2H) 4.50 (s, 3H) 1.67 - 1.70 (m, 3H). LC-MS: m / z [M+H] + = 440.

[0457] Example 36

[0458]

[0459] 36-1: 2-Bromo-1-(tetrahydro-2H-pyran-4-yl)ethanone

[0460] 1-(Tetrahydro-2H-pyran-4-yl)ethanone (1000 mg, 7.8 mmol) was added to methanol (5 mL), and the temperature was lowered to 0 °C. Then bromine (0.4 mL, 7.8 mmol) was added, and the mixture was stirred at 0 °C for 45 minutes, then at room temperature for 45 minutes. After that, sulfuric acid (2.7 mL, 30 mmol) was added, and the mixture was stirred at room temperature overnight. The reaction mixture was quenched with an aqueous solution of sodium bisulfite, then ethyl acetate (300 mL) was added. The ethyl acetate layer was washed with water (200 mL × 3), then dried and concentrated to obtain the title compound (600 mg, 37%).

[0461] 36-2: 6-Bromo-7-methoxy-2-(tetrahydro-2H-pyran-4-yl)imidazo[1,2-a]pyridine

[0462] 5-Bromo-4-methoxypyridin-2-amine (200 mg, 1 mmol) and 2-bromo-1-(tetrahydro-2H-pyran-4-yl)ethanone (600 mg, 3 mmol) were added to anhydrous ethanol (10 mL). The mixture was stirred at 80 °C overnight. The reaction mixture was directly subjected to thin-layer chromatography (petroleum ether / ethyl acetate = 3 / 1) to obtain the title compound (300 mg, 98%). LC-MS: m / z [M+H] + = 311

[0463] 36: 7-Ethyl-4-(4-fluoro-3-(7-methoxy-2-(tetrahydro-2H-pyran-4-yl)imidazo[1,2-a]pyridin- 6-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0464] The experimental procedure was the same as in Example 2, using 6-bromo-7-methoxy-2-(tetrahydro-2H-pyran-4-yl)imidazo[1,2-a]pyridine (80 mg, 0.26 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (50 mg, 0.13 mmol) as starting materials to obtain the title compound (16 mg, 25%).

[0465] 1 H NMR (400 MHz, CHLOROFORM-d) 1.70 (d, J = 7.34 Hz, 3H) 2.07 (br.s., 4H) 3.08 (br.s., 1H) 3.59 (br.s., 2H) 3.89 (br.s., 3H) 4.07 (br.s., 2H) 4.58 (d, J = 6.85 Hz, 2H) 7.12 (br.s., 1H) 7.22 (br.s., 1H) 7.35 - 7.41 (m, 1H) 8.06 (br.s., 1H) 8.28 (br.s., 3H) 9.37 (s, 1H). LC-MS: m / z [M+H] + = 473

[0466] Example 37

[0467]

[0468] 37-1: 6-Bromo-2-cyclopropyl-7-methoxyimidazo[1,2-a]pyridine

[0469] 5-Bromo-4-methoxypyridin-2-amine (2000 mg, 9.85 mmol) and 2-bromo-1-cyclopropylethanone (3211 mg, 19.7 mmol) were added to anhydrous ethanol (20 ml). The tube was sealed and stirred at 90 °C overnight. The reaction mixture was directly subjected to column chromatography (petroleum ether / ethyl acetate = 3 / 1) to obtain the title compound (1900 mg, 72%). LC-MS: m / z [M+H] + = 267

[0470] 37: 4-(3-(2-Cyclopropyl-7-methoxyimidazo[1,2-a]pyridin-6-yl)-4-fluorophenyl)-7-ethyl- 7H-imidazo[4,5-c]pyridazine

[0471] The experimental procedure was the same as in Example 2. Using 6-bromo-2-cyclopropyl-7-methoxyimidazo[1,2-a]pyridine (150 mg, 0.56 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (249 mg, 0.67 mmol) as starting materials, the title compound (83 mg, 34%) was obtained.

[0472] 1 1H NMR (400 MHz, DMSO-d6) 0.78 - 0.91 (m, 4H) 1.54 (s, 3H) 1.94 - 2.00 (m, 1H) 3.79 (s, 3H) 4.46 - 4.54 (m, 2H) 6.96 (s, 1H) 7.54 (s, 2H) 8.11 - 8.16 (m, 1H) 8.47 (s, 1H) 8.50 - 8.56 (m, 1H) 8.85 (s, 1H) 9.55 (s, 1H). LC-MS: m / z [M+H] + = 429

[0473] Example 38

[0474]

[0475] 38-1: 3-Cyclopropyl-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0476] The experimental procedure was the same as in the synthesis method of 5-3 in Example 5. Using 2-hydrazino-4-iodo-3-methoxypyridine (200 mg, 0.76 mmol) and cyclopropanecarbaldehyde (53 mg, 0.76 mmol) as starting materials, the white solid title compound (160 mg, 67%) was obtained. LC-MS: m / z [M+H] + = 316.

[0477] 38: 4-(3-(3-Cyclopropyl-8-methoxy-[1,2,4]triazolo[4,3-a]pyridin-7-yl)-4-fluorophenyl)- 7-ethyl-7H-imidazo[4,5-c]pyridazine

[0478] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (70 mg, 0.2 mmol) and 3-cyclopropyl-7-iodo-8-methoxy-[1,2,4]triazolo[4,3-a]pyridine (50 mg, 0.2 mmol) as raw materials, the yellow solid title compound (43 mg, 50%) was obtained.

[0479] 1 H NMR (400 MHz, CHLOROFORM-d) δ ppm 9.38 (s, 1H) 8.34 (d, J = 5.87 Hz, 1H) 8.29 (br.s., 2H) 7.91 (d, J = 6.85 Hz, 1H) 7.39 (t, J = 9.05 Hz, 1H) 6.92 (d, J = 6.85 Hz, 1H) 4.59 (q, J = 6.85 Hz, 2H) 4.38 - 4.52 (m, 3H) 2.08 (br.s., 1H) 1.70 (t, J = 6.85 Hz, 3H) 1.21 (d, J = 7.83 Hz, 2H) 0.88 (br.s, 2H). LC-MS: m / z [M + H] + = 430.

[0480] Example 39

[0481]

[0482] 39-1: 6-Bromo-2-(bromomethyl)-7-methoxyimidazo[1,2-a]pyridine

[0483] 5-Bromo-4-methoxypyridin-2-amine (300 mg, 1.48 mmol) and dibromoacetone (635 mg, 2.95 mmol) were added to anhydrous ethanol (4 ml), and the mixture was stirred at 90 °C for two hours. The reaction solution was concentrated and directly separated and purified on a preparative plate (petroleum ether / ethyl acetate = 1 / 1) to obtain the title compound (210 mg, 45%). LC-MS: m / z [M + H] + = 321

[0484] 39-2: 6-Bromo-7-methoxy-2-(methoxymethyl)imidazo[1,2-a]pyridine

[0485] 6-Bromo-2-(bromomethyl)-7-methoxyimidazo[1,2-a]pyridine (200 mg, 0.63 mmol) and sodium methoxide (0.5 ml, 4 mmol) were added to methanol (4 ml), and the mixture was stirred at room temperature for two hours. The reaction solution was concentrated and directly separated and purified on a preparative plate (petroleum ether / ethyl acetate = 1 / 1) to obtain the title compound (35 mg, 21%). LC-MS: m / z [M+H] + = 271, 273.

[0486] 39: 7-Ethyl-4-(4-fluoro-3-(7-methoxy-2-(methoxymethyl)imidazo[1,2-a]pyridin-6-yl)benz yl)-7H-imidazo[4,5-c]pyridazine

[0487] The experimental procedure was the same as in Example 2, using 6-bromo-7-methoxy-2-(methoxymethyl)imidazo[1,2-a]pyridine (35 mg, 0.13 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (50 mg, 0.13 mmol) as starting materials to obtain the title compound (21 mg, 38%).

[0488] 1 H NMR (400 MHz, CDCl3) δ 9.37 (s, 1H), 8.31 - 8.22 (m, 3H), 8.05 (s, 1H), 7.45 (s, 1H), 7.40 - 7.33 (m, 1H), 7.00 (br.s., 1H), 4.65 - 4.54 (m, 4H), 3.87 (s, 3H), 3.48 (br.s., 3H), 1.69 - 1.67 (m, 3H). LC-MS: m / z [M+H] + = 433.

[0489] Example 40

[0490]

[0491] 40-1: 5-Bromo-6-methoxy-2-methylimidazo[1,2-a]pyridine

[0492] 6-Bromo-5-methoxypyridin-2-amine (90 mg, 0.45 mmol) and bromoacetone (120 mg, 0.88 mmol) were added to anhydrous ethanol (10 mL), and the mixture was reacted at 90 °C for 16 hours, concentrated, and prepared on a preparative plate (petroleum ether:ethyl acetate = 1:2) to obtain a yellow oil (35 mg, yield 32%). LC-MS: m / z [M+H] + = 241, 243.

[0493] 40: 7-Ethyl-4-(4-fluoro-3-(6-methoxy-2-methylimidazo[1,2-a]pyridin-5-yl)phenyl)-7H- imidazo[4,5-c]pyridazine

[0494] The experimental operation was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (54 mg, 0.15 mmol) and 5-bromo-6-methoxy-2-methylimidazo[1,2-a]pyridine (35 mg, 0.15 mmol) as raw materials, a brown solid (25 mg, yield 41%) was obtained.

[0495] 1 H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H), 8.43 (br.s., 2H), 8.28 (s, 2H), 7.50 (t, J = 9.0 Hz, 1H), 7.36 - 7.28 (m, 1H), 7.11 (br.s., 1H), 4.61 - 4.56 (m, 2H), 3.85 (br.s., 3H), 2.46 - 2.32 (m, 3H), 1.71 - 1.67 (m, 3H). LC-MS: m / z [M+H] + = 403.

[0496] Example 41

[0497]

[0498] 41-1: 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-2-carbaldehyde

[0499] 5-Bromo-4-methoxypyridin-2-amine (610 mg, 3.0 mmol) and 1,1,3-trichloroacetone (720 mg, 4.5 mmol) were added to 1,2-dimethoxyethane (2 ml), and the mixture was stirred at room temperature for 24 hours. The reaction solution was filtered by suction, and the obtained white solid was dissolved in ethanol (4 ml). The solution was reacted at 95 °C for 24 hours, and then the reaction solution was concentrated and added to dichloromethane (5 ml) and trifluoroacetic acid (0.5 ml). The mixture was stirred at room temperature for 1 hour, and then the reaction solution was concentrated. The title compound (60 mg, 7.8%) was obtained by preparative thin-layer chromatography (dichloromethane / methanol = 10 / 1). LC-MS: m / z [M+H] + = 255, 257

[0500] 41-2: 6-Bromo-2-(difluoromethyl)-7-methoxyimidazo[1,2-a]pyridine

[0501] 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-2-carbaldehyde (60 mg, 0.235 mmol) was added to dichloromethane (2 ml), and (diethylamino) sulfur trifluoride (0.05 ml) was added to the reaction solution. The mixture was stirred at room temperature for 1 hour, and then 0.5 ml of the reaction solution was quenched and concentrated. The title compound (17 mg, 26%) was obtained by preparative thin-layer chromatography (petroleum ether / ethyl acetate / dichloromethane = 3 / 1 / 0.1). LC-MS: m / z [M+H]+ = 277,279.

[0502] 41: 4-(3-(2-(Difluoromethyl)-7-methoxyimidazo[1,2-a]pyridin-6-yl)-4-fluorophenyl)-7-eth yl-7H-imidazo[4,5-c]pyridazine

[0503] The experimental operation was the same as that in Example 19. Using 6-bromo-2-(difluoromethyl)-7-methoxyimidazo[1,2-a]pyridine (9 mg, 0.032 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (12 mg, 0.032 mmol) as raw materials, the title compound (7 mg, 50%) was obtained.

[0504] 1 H NMR (400 MHz, CHLOROFORM-d) δ = 9.38 (s, 1H), 8.29 (br.s., 3H), 8.10 (s, 1H), 7.69 (s, 1H), 7.38 (s, 1H), 7.05 - 6.67 (m, 2H), 4.59 (q, J = 7.0 Hz, 2H), 3.88 (s, 3H), 1.70 (br.s., 3H). LC-MS: m / z [M+H] + = 439.

[0505] Example 42

[0506]

[0507] 42-1: 5-Bromo-2-(methoxycarbonyl)-3-methylpyridine 1-oxide

[0508] Methyl 5-bromo-3-methylpicolinate (1.2 g, 5.22 mmol) and m-chloroperbenzoic acid (3 g, 17.44 mmol) were added to dichloromethane (100 mL), stirred at room temperature for 16 hours, concentrated, and purified by column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain the title compound as a white solid (1.06 g, yield 83%). LC-MS: m / z [M+H] + = 246,248.

[0509] 42-2: Methyl 5-bromo-6-chloro-3-methylpicolinate

[0510] 5-Bromo-2-(methoxycarbonyl)-3-methylpyridine 1-oxide (1.05 g, 4.30 mmol) and triethylamine (5 g, 49.5 mmol) were added to dichloromethane (100 mL). Oxalyl chloride (2.5 g, 20.5 mmol) was added dropwise under ice bath, and the mixture was stirred at room temperature for 1 hour, filtered, and the mother liquor was concentrated. Purification by column chromatography (petroleum ether:ethyl acetate = 5:1) gave the title compound as a light yellow solid (0.52 g, yield 44%). LC-MS: m / z [M+H]+ = 264,266.

[0511] 42-3: Methyl 5-bromo-3-(bromomethyl)-6-chloropicolinate

[0512] Methyl 5-bromo-6-chloro-3-methylpicolinate (0.52 g, 1.90 mmol), NBS (0.48 g, 2.7 mmol) and AIBN (30 mg) were added to carbon tetrachloride (10 mL). The mixture was stirred at 65 °C for 16 h, concentrated, and purified by preparative TLC (petroleum ether:ethyl acetate = 5:1) to obtain a mixture containing the title compound and the starting material (0.5 g, 1:1 crude product). LC-MS: m / z [M+H] + = 342,344,346.

[0513] 42-4: 3-Bromo-2-chloro-6-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one

[0514] Methyl 5-bromo-3-(bromomethyl)-6-chloropicolinate (0.5 g, crude product), methylamine hydrochloride (200 mg, 3 mmol) and triethylamine (0.5 g, 4.95 mmol) were added to acetonitrile (10 mL). The mixture was stirred at room temperature for 2 h, 100 mL of saturated ammonium chloride solution was added, and the mixture was extracted with ethyl acetate (3 × 100 mL). The mother liquor was concentrated and purified by preparative TLC to obtain the title compound as a white solid (200 mg). LC-MS: m / z [M+H] + = 261,263.

[0515] 42-5: 3-Bromo-2-methoxy-6-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one

[0516] 3-Bromo-2-chloro-6-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (120 mg, 0.46 mmol) and sodium phosphate (250 mg, 1.52 mmol) were added to methanol (5 mL). The mixture was stirred at 60 °C for 16 h, filtered, and the mother liquor was concentrated. Purification by preparative TLC gave the title compound as a white solid (17 mg, 14%). LC-MS: m / z [M+H] + = 257,259.

[0517] 42: 3-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-2-methoxy-6-methyl- 5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one

[0518] The experimental procedure was the same as in Example 2, using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (25 mg, 0.07 mmol) and 3-bromo-2-methoxy-6-methyl-5,6-dihydro-7H-pyrrolo[3,4-b]pyridin-7-one (15 mg, 0.06 mmol) as starting materials to obtain a brown solid (12 mg, 48% yield).

[0519] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.37 (s, 1H), 8.28 (s, 3H), 7.78 (s, 1H), 7.37 (t, J = 9.3 Hz, 1H), 4.67 - 4.52 (m, 2H), 4.38 (s, 2H), 4.10 (s, 3H), 3.28 (s, 3H), 1.71 - 1.68 (m, 3H). LC-MS: m / z [M+H] + = 419.

[0520] Example 43

[0521]

[0522] 43-1: 6-Bromo-7-methoxy-2-(trifluoromethyl)imidazo[1,2-a]pyridine

[0523] 5-Bromo-4-methoxypyridin-2-amine (202 mg, 1.0 mmol) was added to a mixed solvent of ethanol (1.5 ml) and 1,4-dioxane (0.5 ml). 3-Chloro-1,1,1-trifluoroacetone (161 mg, 1.1 mmol) was slowly added to the reaction solution, and the mixture was stirred at room temperature for 6 hours. Triethylamine (202 mg, 2.0 mmol) was added to the reaction solution, and the reaction was carried out at 95 °C overnight. The reaction solution was filtered by suction, concentrated, and purified by preparative thin-layer chromatography (petroleum ether / ethyl acetate = 20 / 1) to obtain the title compound (50 mg, 16.9%). LC-MS: m / z [M+H] + = 295, 297.

[0524] 43 : 7-Ethyl-4-(4-fluoro-3-(7-methoxy-2-(trifluoromethyl)imidazo[1,2-a]pyridin-6-yl)phenyl) -7H-imidazo[4,5-c]pyridazine

[0525] The experimental procedure was the same as that of Example 19, using 6-bromo-7-methoxy-2-(trifluoromethyl)imidazo[1,2-a]pyridine (50 mg, 0.170 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (58 mg, 0.155 mmol) as starting materials to obtain the title compound (32 mg, 45%).

[0526] 11H NMR (400 MHz, CHLOROFORM-d) 9.36 (br.s., 1H), 8.27 (br.s., 3H), 8.09 (s, 1H), 7.76 (s, 1H), 7.36 (t, J = 8.6 Hz, 1H), 7.01 (s, 1H), 4.57 (d, J = 7.3 Hz, 2H), 3.86 (s, 3H), 1.68 (br.s., 3H). LC-MS: m / z [M+H] + = 457.

[0527] Example 44

[0528]

[0529] 44-1: 4-Bromo-2-hydrazinyl-5-methoxypyridine

[0530] 4-Bromo-2-fluoro-5-methoxypyridine (560 mg, 2.72 mmol) and hydrazine hydrate (1360 mg, 27.20 mmol) were added to ethanol (10 mL), and the mixture was stirred at 80 °C for 16 h. The reaction mixture was concentrated, and the title compound as a yellow oily liquid (110 mg, 20%) was obtained by separation on preparative TLC (ethyl acetate). LC-MS: m / z [M+H] + = 218, 220.

[0531] 44-2: 7-Bromo-6-methoxy-[1,2,4]triazolo[4,3-a]pyridine

[0532] 4-Bromo-2-hydrazino-5-methoxypyridine (110 mg, 0.50 mmol) was added to formic acid (5 mL), and the mixture was stirred at 110 °C for 16 h. After the reaction mixture was filtered and concentrated, the title compound as a white solid (30 mg, 26%) was obtained by separation on preparative TLC (dichloromethane / methanol = 20 / 1). LC-MS: m / z [M+H] + = 228, 230.

[0533] 44: 7-Ethyl-4-(4-fluoro-3-(6-methoxy-[1,2,4]triazolo[4,3-a]pyridin-7-yl)phenyl)-7H- imidazo[4,5-c]pyridazine

[0534] The experimental procedure was the same as that in Example 2, using 7-bromo-6-methoxy-[1,2,4]triazolo[4,3-a]pyridine (30 mg, 0.13 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (48 mg, 0.13 mmol) as starting materials, to obtain the title compound as a yellow solid (3 mg, 6%).

[0535] 11H NMR (400 MHz, CHLOROFORM-d) δ 9.37 (s, 1H), 8.83 (s, 1H), 8.34 (d, J = 6.4 Hz, 1H), 8.28 (s, 2H), 7.82 (s, 1H), 7.71 (s, 1H), 7.37 (t, J = 9.0 Hz, 1H), 4.58 (q, J = 7.3 Hz, 2H), 3.86 (s, 3H), 1.69 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 390.

[0536] Example 45

[0537]

[0538] 45-1: (6-Bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)methanol

[0539] Methyl 6-bromo-7-methoxyimidazo[1,2-a]pyridine-2-carboxylate (800 mg, 2.81 mmol) was added to dichloromethane (4 mL), and then a hexane solution of diisobutylaluminum hydride (1 M, 4 mL) was added. After stirring at room temperature for 16 hours, the reaction mixture was filtered and concentrated. The title compound as a yellow solid (190 mg, 26%) was obtained by preparative thin-layer chromatography (dichloromethane / methanol = 10 / 1). LC-MS: m / z [M+H] + = 257, 259.

[0540] 45: (6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxyimidazo [1,2-a]pyridin-2-yl)methanol

[0541] The experimental procedure was the same as in Example 2, using (6-bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)methanol (50 mg, 0.19 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (70 mg, 0.19 mmol) as starting materials to obtain the title compound as a brown solid (15 mg, 18%).

[0542] 1 1H NMR (400 MHz, CHLOROFORM-d) δ 9.23 (s, 1H), 8.32 (s, 1H), 8.20 - 8.10 (m, 3H), 7.45 (s, 1H), 7.30 (t, J = 9.3 Hz, 1H), 7.20 - 6.98 (m, 1H), 4.67 (s, 2H), 4.50 (q, J = 7.2 Hz, 2H), 3.80 (s, 3H), 1.60 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 419.

[0543] Example 46

[0544]

[0545] 46-1: 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-3-carbaldehyde

[0546] 5-Bromo-4-methoxypyridin-2-amine (300 mg, 1.48 mmol) and 2-bromomalonaldehyde (335 mg, 2.22 mmol) were added to ethanol (10 mL). After stirring at 80 °C for 0.5 h, sodium bicarbonate (249 mg, 2.96 mmol) was added and the mixture was stirred at 80 °C for 16 h. The reaction mixture was filtered and concentrated, and the title compound as a yellow solid (120 mg, 25%) was separated by preparative TLC (ethyl acetate). LC-MS: m / z [M+H] + = 255, 257.

[0547] 46-2: 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-3-methanol

[0548] 6-Bromo-7-methoxyimidazo[1,2-a]pyridine-3-carbaldehyde (120 mg, 0.47 mmol) was added to dichloromethane (4 mL), and then a hexane solution of diisobutylaluminum hydride (1 M, 4 mL) was added. After stirring at room temperature for 16 h, the reaction mixture was filtered and concentrated, and the title compound as a white solid (40 mg, 33%) was separated by preparative TLC (dichloromethane / methanol = 10 / 1). LC-MS: m / z [M+H] + = 257, 259.

[0549] 46: (6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxyimidazo [1,2-a]pyridin-3-yl)methanol

[0550] The experimental procedure was the same as that of Example 2, using 6-bromo-7-methoxyimidazo[1,2-a]pyridin-3-methanol (40 mg, 0.16 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (59 mg, 0.16 mmol) as starting materials, to give the title compound as a brown solid (6 mg, 8%).

[0551] 11H NMR (400 MHz, DMSO-d6) δ 9.57 - 9.54 (m, 1H), 8.87 - 8.84 (m, 1H), 8.59 - 8.53 (m, 1H), 8.53 - 8.47 (m, 2H), 7.58 - 7.53 (m, 1H), 7.52 - 7.49 (m, 1H), 7.26 - 7.15 (m, 1H), 5.33 - 5.26 (m, 1H), 4.79 - 4.75 (m, 2H), 4.53 - 4.47 (m, 2H), 3.86 (s, 3H), 1.54 (s, 3H). LC-MS: m / z [M+H] + = 419.

[0552] Example 47

[0553]

[0554] 47-1: 3-Bromo-1,8-naphthyridin-2(1H)-one

[0555] 2-Oxo-1,2-dihydro-1,8-naphthyridine-3-carboxylic acid (490 mg, 2.58 mmol) was added to N,N-dimethylformamide (10 mL), and bromine (2 g, 12.9 mmol) and pyridine (5 mL) were added. The mixture was stirred at 100 °C for 1 hour. 5 mL of saturated aqueous sodium bisulfite solution was added dropwise to the reaction mixture, and then the mixture was extracted with ethyl acetate (3 x 200 mL). The ethyl acetate layer was washed three times with water and once with saturated brine, then dried over anhydrous sodium sulfate and concentrated. The crude product was purified by thin-layer chromatography (petroleum ether / ethyl acetate = 4 / 1) to obtain the title compound (140 mg, 21%). LC-MS: m / z [M+H] + = 225

[0556] 47-2: 3-Bromo-2-methoxy-1,8-naphthyridine

[0557] 3-Bromo-1,8-naphthyridin-2(1H)-one (140 mg, 0.63 mmol) was added to dichloromethane / methanol (5 mL / 2 mL), and then trimethylsilyldiazomethane (2 mL) was added. The mixture was stirred at room temperature overnight. The reaction mixture was directly concentrated and then purified by thin-layer chromatography (petroleum ether / ethyl acetate = 4 / 1) to obtain the title compound (40 mg, 27%). LC-MS: m / z [M+H] + = 239

[0558] 47: 3-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-2-methoxy-1,8-naph thyridine

[0559] The experimental procedure was the same as in Example 19. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (74 mg, 0.2 mmol) and 3-bromo-2-methoxy-1,8-naphthyridine (40 mg, 0.17 mmol) as starting materials, the title compound (38 mg, 48%) was obtained.

[0560] 1 H NMR (400 MHz, CHLOROFORM-d) 9.39 (s, 1H) 8.66 (d, J = 3.42 Hz, 1H) 8.43 (d, J = 4.89 Hz, 1H) 8.29 (br.s., 1H) 8.27 (s, 1H) 7.95 (d, J = 6.36 Hz, 1H) 7.90 (s, 1H) 7.39 (t, J = 9.05 Hz, 1H) 7.23 (d, J = 7.83 Hz, 1H) 4.58 (q, J = 7.34 Hz, 2H) 3.94 (s, 3H) 1.69 (t, J = 7.34 Hz, 3H). LC-MS: m / z [M+H] + = 401.

[0561] Example 48

[0562]

[0563] 48-1: 6-Bromo-7-methoxyimidazo[1,2-a]pyrimidine

[0564] 5-Bromo-4-methoxypyrimidin-2-amine (203 mg, 1.0 mmol) and chloroacetaldehyde (94 mg, 1.2 mmol) were added to ethanol (2 ml), and the mixture was stirred at room temperature overnight. Sodium bicarbonate (168 mg, 2.0 mmol) was added to the reaction mixture, and the reaction was carried out at 60 °C for 2 hours. The reaction mixture was filtered by suction, concentrated, and purified by preparative thin-layer chromatography (dichloromethane / methanol = 20 / 1) to obtain the title compound (57 mg, 25%). LC-MS: m / z [M+H] + = 228, 230.

[0565] 48: 7-Ethyl-4-(4-fluoro-3-(7-methoxyimidazo[1,2-a]pyrimidin-6-yl)phenyl)-7H-imidazo [4,5-c]pyridazine

[0566] The experimental procedure was the same as in Example 19. Using 6-bromo-7-methoxyimidazo[1,2-a]pyrimidine (57 mg, 0.251 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (92 mg, 0.251 mmol) as starting materials, the title compound (50 mg, 52%) was obtained.

[0567] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.37 (s, 1H), 8.31 (d, J = 16.6 Hz, 4H), 7.57 (br.s., 1H), 7.44 - 7.34 (m, 2H), 4.59 (q, J = 7.3 Hz, 2H), 4.08 (s, 3H), 1.72 - 1.68 (m, 3H). LC-MS: m / z [M+H] + = 390.

[0568] Example 49

[0569]

[0570] 49-1: 5-Bromo-6-methoxyimidazo[1,2-a]pyridine

[0571] 6-Bromo-5-methoxypyridin-2-amine (200 mg, 0.99 mmol) and chloroacetaldehyde (40%, 290 mg, 1.49 mmol) were added to anhydrous methanol (10 mL), stirred at room temperature for 1 hour, then sodium bicarbonate (200 mg, 2.38 mmol) was added, and the reaction was carried out at 60 °C for 16 hours. After concentration, preparative thin layer chromatography (petroleum ether:ethyl acetate = 3:1) was used to obtain a light yellow solid (130 mg, yield 58%). LC-MS: m / z [M+H] + = 227, 229.

[0572] 49: 7-Ethyl-4-(4-fluoro-3-(6-methoxyimidazo[1,2-a]pyridin-5-yl)phenyl)-7H-imidazo [4,5-c]pyridazine

[0573] The experimental procedure was the same as that of Example 2, using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (36 mg, 0.1 mmol) and 5-bromo-6-methoxyimidazo[1,2-a]pyridine (23 mg, 0.1 mmol) as starting materials to obtain a brown solid (7 mg, yield 18%).

[0574] 1 1H NMR (400 MHz, CHLOROFORM-d) 9.38 (s, 1H), 8.47 - 8.39 (m, 2H), 8.28 (s, 1H), 7.84 - 7.59 (m, 1H), 7.50 (t, J = 8.8 Hz, 1H), 7.41 - 7.26 (m, 2H), 7.25 - 6.97 (m, 1H), 4.58 (q, J = 7.3 Hz, 2H), 3.85 (s, 3H), 1.70 - 1.65 (m, 3H). LC-MS: m / z [M+H] + = 389.

[0575] Example 50

[0576]

[0577] 50: 7-Ethyl-4-(4-fluoro-3-(7-methoxy-2-methylimidazo[1,2-a]pyridin-6-yl)phenyl)-7H- imidazo[4,5-c]pyridazine

[0578] The experimental procedure was the same as that in Example 2. Using 6-bromo-7-methoxy-2-methylimidazo[1,2-a]pyridine (30 mg, 0.12 mmol) and 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (44 mg, 0.12 mmol) as starting materials, the white solid title compound (13 mg, 27%) was obtained.

[0579] 1 H NMR (400 MHz, CHLOROFORM-d) 9.35 (s, 1H), 8.32 - 8.16 (m, 3H), 7.98 (s, 1H), 7.34 (t, J = 8.8 Hz, 1H), 7.20 (s, 1H), 6.90 (br.s., 1H), 4.57 (q, J = 7.3 Hz, 2H), 3.93 - 3.74 (m, 3H), 2.47 - 2.33 (m, 3H), 1.68 (t, J = 7.1 Hz, 3H). LC-MS: m / z [M+H] + = 403.

[0580] Example 51

[0581]

[0582] 51-1: 6-Bromo-5-methoxyimidazo[1,2-a]pyridine

[0583] 5-Bromo-6-methoxypyridin-2-amine (200 mg, 0.99 mmol) and chloroacetaldehyde (40%, 290 mg, 1.49 mmol) were added to anhydrous methanol (10 mL), stirred at room temperature for 1 hour, then sodium bicarbonate (200 mg, 2.38 mmol) was added, and the reaction was carried out at 70 °C for 16 hours. After concentration, purification by preparative thin layer chromatography (petroleum ether:ethyl acetate = 3:1) gave a light yellow solid (70 mg, yield 31%). LC-MS: m / z [M+H] + = 227, 229.

[0584] 51: 7-Ethyl-4-(4-fluoro-3-(5-methoxyimidazo[1,2-a]pyridin-6-yl)phenyl)-7H-imidazo [4,5-c]pyridazine

[0585] The experimental procedure was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (36 mg, 0.1 mmol) and 6-bromo-5-methoxyimidazo[1,2-a]pyridine (23 mg, 0.1 mmol) as starting materials, a brown solid (4 mg, yield 10%) was obtained.

[0586] 1 H NMR (400 MHz, CHLOROFORM-d) 9.39 (s, 1H), 8.41 (d, J = 4.9 Hz, 1H), 8.29 (br.s., 2H), 7.76 (br.s., 2H), 7.49 - 7.27 (m, 3H), 4.68 - 4.50 (m, 2H), 3.84 (s, 3H), 1.69 (br.s., 3H). LC-MS: m / z [M + H] + =389.

[0587] Example 52

[0588]

[0589] 52: 7-Ethyl-4-(4-fluoro-3-(7-methoxyimidazo[1,2-a]pyridin-6-yl)phenyl)-7H-imidazo [4,5-c]pyridazine

[0590] The experimental procedure was the same as that in Example 2. Using 7-ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (50 mg, 0.14 mmol) and 6-bromo-7-methoxyimidazo[1,2-a]pyridine (30 mg, 0.14 mmol) as starting materials, the yellow solid title compound (8 mg, 15%) was obtained.

[0591] 1 H NMR (400 MHz, DMSO-d6) δ 9.57 (s, 1H) 8.87 (s, 1H) 8.67 (s, 1H) 8.48 - 8.61 (m, 2H) 7.82 (br.s., 1H) 7.46 - 7.65 (m, 2H) 7.17 (br.s., 1H) 4.51 (q, J = 6.85 Hz, 2H) 3.84 (s, 3H) 1.55 (t, J = 7.09 Hz, 3H). LC-MS: m / z [M + H] + =389.

[0592] Example 53

[0593]

[0594] 53-1: N-(4-(Methoxymethyl)pyridin-2-yl)-1,1-diphenylmethanamine

[0595] 2-Chloro-4-(methoxymethyl)pyridine (2.87 g, 18.28 mmol), dibenzylamine (3.3 g, 18.28 mmol), R-(+)-1,1'-binaphthalene-2,2'-diphenylphosphine (1.10 g, 1.82 mmol), and cesium carbonate (8.30 g, 25.59 mmol) were added to a solution of 1,4-dioxane (50 mL). The mixture was purged with argon three times and heated to 80 °C for 15 hours. After cooling to room temperature, the reaction mixture was poured into ice water (40 mL), and the product was extracted with ethyl acetate (50 mL × 3). The organic layer was washed with saturated aqueous sodium chloride solution (50 mL × 3), dried, and concentrated. The residue was purified by prep-HPLC to obtain a yellow oily liquid (3.4 g, 61.8%). LC-MS: m / z [M+1] + : 303

[0596] 53-2: 4-(Methoxymethyl)pyridin-2-amine

[0597] N-(4-(Methoxymethyl)pyridin-2-yl)-1,1-diphenylmethanamine (3.3 g, 11 mmol) was dissolved in a solution of tetrahydrofuran (50 mL), and then 1,4-dioxane (17 mL) containing hydrochloric acid was added. The mixture was stirred at room temperature for 2 hours. After the reaction was complete, saturated sodium bicarbonate (30 mL) was added to adjust the pH to about 7. The product was extracted with ethyl acetate (50 mL × 3). The organic layer was washed with saturated aqueous sodium chloride solution (50 mL × 3), dried, and concentrated. The residue was purified by prep-HPLC to obtain a white solid (800 mg, 53.3%). LC-MS: m / z [M+1] + : 139

[0598] 53-3: 5-Bromo-4-(methoxymethyl)pyridin-2-amine

[0599] 5-Bromo-4-(methoxymethyl)pyridin-2-amine (260 mg, 1.88 mmol) and ammonium acetate (14.5 mg, 0.188 mmol) were added to a solution of acetonitrile (25 mL). NBS (167.7 mg, 0.94 mmol) was added portionwise at 0 °C. After removing the ice bath, the mixture was stirred at room temperature for 40 minutes. Dichloromethane (20 mL) was added to dissolve the product, and saturated sodium bicarbonate (40 mL) was added to adjust the pH to about 7. The product was extracted with dichloromethane (50 mL × 4). The organic layer was dried and concentrated. The residue was purified by prep-HPLC to obtain a white solid (220 mg, 40%). LC-MS: m / z [M+1] + : 219

[0600] 53-4: 6-Bromo-2-(1-fluorocyclopropyl)-7-(methoxymethyl)imidazo[1,2-a]pyridine

[0601] Dissolve 5-bromo-4-(methoxymethyl)pyridin-2-amine (524 mg, 2.5 mmol), 2-chloro-1-(1-fluorocyclopropyl)ethan-1-one (670 mg, 5 mmol), and cesium carbonate (1.6 g, 5 mmol) in ethanol (10.0 mL). Heat the solution to 100 °C in a microwave reactor and react for 1 hour. Purify the reaction solution by preparative HPLC to obtain (100 mg, 26%) of a white solid. LC-MS: m / z [M+1] + = 300

[0602] 53: 7-Ethyl-4-(4-fluoro-3-(2-(1-fluorocyclopropyl)-7-(methoxymethyl)imidazo[1,2-a]pyridin-6-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0603] Using 6-bromo-2-(1-fluorocyclopropyl)-7-(methoxymethyl)imidazo[1,2-a]pyridine (50.0 mg, 0.17 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (105 mg, 0.36 mmol) as starting materials, the title compound (20 mg, 26%) of an off-white solid was obtained.

[0604] 1 H NMR (400 MHz, CHLOROFORM-d) δ = 9.39 (s, 1H), 8.30 (d, J = 10.8 Hz, 3H), 8.13 (br.s., 1H), 7.81 (br.s., 1H), 7.70 (s, 1H), 7.40 (t, J = 8.6 Hz, 1H), 4.59 (q, J = 7.0 Hz, 2H), 4.38 (s, 2H), 3.31 (s, 3H), 1.70 (t, J = 7.1 Hz, 3H), 1.54 (d, J = 19.6 Hz, 2H), 1.26 (d, J = 14.5 Hz, 2H). LC-MS: m / z [M+1] + = 461

[0605] Example 54

[0606]

[0607] 54-1: (2,4-Dichloropyridin-3-yl)methanol

[0608] Under nitrogen protection, dissolve 2,4-dichloronicotinaldehyde (5 g, 28.6 mmol) in 50 ml of ethanol. Cool the solution to 0 °C. At this temperature, slowly add sodium borohydride (1.4 g, 37.2 mmol). Restore to room temperature and react for 16 hours. Add it to an aqueous solution of ammonium chloride with ice, and extract with dichloromethane (100 ml x 3). Concentrate the organic phase to obtain (2,4-dichloropyridin-3-yl)methanol (4.8 g, 94.1%) as a yellow solid. LC-MS: m / z [M+H] + = 178.

[0609] 54-2: 2,4-Dichloro-3-(methoxymethyl)pyridine

[0610] Under nitrogen protection, dissolve (2,4-dichloropyridin-3-yl)methanol (4.8 g, 27 mmol) in 50 ml of N,N-dimethylformamide. Cool the solution to 0 °C. At this temperature, slowly add NaH (2.2 g, 54 mmol). React under an ice bath for half an hour, then add methyl iodide (4.6 g, 32.4 mmol). React at room temperature for 16 hours. After the reaction is completed, add the reaction solution to 100 ml of ice water, and extract with ethyl acetate (100 ml x 3), and wash with water (50 mL x 2). Spin-dry the organic phase to obtain 2,4-dichloro-3-(methoxymethyl)pyridine (2.3 g, 44.5%) as a pale yellow liquid. 1H NMR (400 MHz, CDCl3) δ 8.16 (d, J = 5.1 Hz, 1H), 7.23 (d, J = 5.2 Hz, 1H), 4.64 (s, 2H), 3.38 (s, 3H). LC-MS: m / z [M+H] + = 192

[0611] 54-3: N-(4-Chloro-3-(methoxymethyl)pyridin-2-yl)-1,1-diphenylmethanamine

[0612] Under nitrogen protection, dissolve 2,4-dichloro-3-(methoxymethyl)pyridine (1 g, 5.8 mmol) and dibenzylamine (1.1 g, 5.8 mmol) in 15 mL, then add 1,1'-binaphthalene-2,2'-bis(diphenylphosphine) (361 mg, 0.58 mmol), cesium carbonate (2.83 g, 8.7 mmol), and finally add palladium acetate (130 mg, 0.58 mmol). React at 90 °C for 16 hours. After the reaction is completed, add the reaction solution to 60 ml of water, and extract with ethyl acetate (50 mL x 3). Spin-dry the organic phase and perform column chromatography (petroleum ether / ethyl acetate = 10 / 1). Spin-dry the organic phase to obtain N-(4-chloro-3-(methoxymethyl)pyridin-2-yl)-1,1-diphenylmethanamine (700 mg, 40%) as a yellow oily liquid. LC-MS: m / z [M+H] + = 337

[0613] 54-4: 4-Chloro-3-(methoxymethyl)pyridin-2-amine

[0614] Under nitrogen protection, N-(4-chloro-3-(methoxymethyl)pyridin-2-yl)-1,1-diphenylmethylaniline (0.7 g, 2.1 mmol) was added to 10 ml of tetrahydrofuran, and then 8 ml of dioxane hydrochloride solution was added. After reacting at room temperature for 16 hours, the reaction solution was added to 20 ml of sodium bicarbonate solution, and extracted with ethyl acetate (30 ml x 3). The organic phase was dried by rotation, and column chromatography (petroleum ether / ethyl acetate = 2 / 1) was carried out to obtain 4-chloro-3-(methoxymethyl)pyridin-2-amine (220 mg, 20%) as a white solid.

[0615] 1 HNMR(400MHz,CDCl3)7.85(d,J=5.7Hz,1H),6.71(d,J=5.8Hz,1H),5.72(s,2H),4.69(s,2H),3.37(s,3H).LC-MS:m / z[M+H] + =173

[0616] 54-5: 7-Chloro-8-(methoxymethyl)-3-methylimidazo[1,2-a]pyridine

[0617] Under nitrogen protection, 4-chloro-3-(methoxymethyl)pyridin-2-amine (50 mg, 0.29 mmol) and 1,1-dimethoxy-2-bromopropane (265 mg, 1.45 mmol) were dissolved in 2 mL of ethanol, and then 0.2 ml of hydrochloric acid methanol solution was added. The reaction was carried out at 120 °C under microwave for 2 hours. It was directly dried by rotation for the next step to obtain 7-chloro-8-(methoxymethyl)-3-methylimidazo[1,2-a]pyridine (70 mg, 100%) as a white solid. LC-MS: m / z [M+H] + =211

[0618] 54: 7-Ethyl-4-(4-fluoro-3-(8-(methoxymethyl)-3-methylimidazo[1,2-a]pyridin-7-yl)phenyl)- 7H-imidazo[4,5-c]pyridazine

[0619] The experimental operation was the same as that in Example 2. Using 7-chloro-8-(methoxymethyl)-3-methylimidazo[1,2-a]pyridine (70 mg, 0.33 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (95 mg, 0.33 mmol) as raw materials, the title compound (16.1 mg, 11.6%) was obtained as a white solid.

[0620] 1HNMR (400 MHz, DMSO-d6) 9.54 (s, 1H), 8.87 (s, 1H), 8.61–8.53 (m, 2H), 8.35 (d, J = 7.1 Hz, 1H), 7.59 (t, J = 9.3 Hz, 1H), 7.46 (d, J = 0.7 Hz, 1H), 7.00 (d, J = 7.0 Hz, 1H), 4.72 (s, 2H), 4.52 (q, J = 7.3 Hz, 2H), 3.11 (d, J = 3.8 Hz, 3H), 2.53 (s, 3H), 1.64–1.47 (m, 3H). LC-MS: m / z [M+H] + = 417

[0621] Examples 55 and 56

[0622]

[0623] 55-1: 1-(6-Bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)ethan-1-one

[0624] 5-Bromo-4-methoxypyridin-2-amine (500 mg, 2.46 mmol) and 1-bromobutane-2,3-dione (406 mg, 2.46 mmol) were added to ethanol (10 mL), and the mixture was stirred at 90 °C overnight. The reaction solution was directly subjected to thin-layer chromatography (petroleum ether / ethyl acetate = 1 / 1) to obtain the yellow solid title compound (150 mg, 22.66%). LC-MS: m / z [M+H]+ = 269

[0625] 55-2: 1-(6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxyimi dazo[1,2-a]pyridin-2-yl)ethan-1-one

[0626] The experimental procedure was the same as that of Example 2, using 1-(6-bromo-7-methoxyimidazo[1,2-a]pyridin-2-yl)ethan-1-one (150 mg, 0.56 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (161 mg, 0.56 mmol) as starting materials to obtain the yellow solid title compound (100 mg, 41.29%). LC-MS: m / z [M+H] + = 431

[0627] 55: (Z)-1-(6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxy imidazo[1,2-a]pyridin-2-yl)ethan-1-one O-methyl oxime

[0628] 56: (E)-1-(6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxy imidazo[1,2-a]pyridin-2-yl)ethan-1-one O-methyl oxime

[0629] 1-(6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxyimidazo[1,2-a]pyridin-2-yl)ethan-1-one (100 mg, 0.23 mmol) and methoxylamine hydrochloride (58 mg, 0.69 mmol) were added to ethanol (10 ml). Stir at room temperature for 1 hour. The reaction mixture was directly purified by thin layer chromatography (dichloromethane / methanol = 20 / 1) to obtain yellow solid Example 55 (6 mg, 5%) and Example 56 (15 mg, 13%).

[0630] Example 55: 1 H NMR (400 MHz, DMSO-d6) ppm 1.50 - 1.57 (m, 3H) 2.26 - 2.32 (m, 3H) 3.80 - 3.85 (m, 3H) 3.89 - 3.97 (m, 3H) 4.47 - 4.54 (m, 2H) 7.12 - 7.17 (m, 1H) 7.52 - 7.58 (m, 1H) 8.44 - 8.59 (m, 3H) 8.65 - 8.71 (m, 1H) 8.83 - 8.89 (m, 1H) 9.52 - 9.60 (m, 1H). LC-MS: m / z [M+H] + = 460

[0631] Example 56: 1 H NMR (400 MHz, DMSO-d6) ppm 1.54 (t, J = 7.34 Hz, 3H) 2.21 - 2.29 (m, 3H) 3.83 (s, 3H) 3.89 (s, 3H) 4.49 - 4.53 (m, 2H) 7.11 (s, 1H) 7.54 (t, J = 8.80 Hz, 1H) 8.02 (s, 1H) 8.48 - 8.60 (m, 3H) 8.86 (s, 1H) 9.56 (s, 1H). LC-MS: m / z [M+H] + = 460

[0632] Example 57

[0633]

[0634] 57-1: 2-(6-Bromo-7-methoxy[1,2-a]pyridin-2-yl)propan-2-ol

[0635] Methylmagnesium chloride (620 mg, 8.35 mmol) and methyl 6-bromo-7-methoxyimidazo[1,2-a]pyridine-2-carboxylate (500 mg, 1.67 mmol) were added to tetrahydrofuran (20 mL), and the mixture was stirred at room temperature for 1 hour. The reaction solution was adjusted to acidic with aqueous hydrochloric acid (1 N), concentrated, then adjusted to basic with saturated aqueous sodium bicarbonate, extracted with dichloromethane (50 mL×3). The organic phase was washed with saturated brine (50 mL), dried over sodium sulfate, concentrated, and separated by preparative thin-layer chromatography (dichloromethane / methanol = 20 / 1) to obtain the title compound (130 mg, 27%). LC-MS: m / z [M+H]+ = 285, 287.

[0636] 57: 2-(6-(5-(7-Ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)-7-methoxyimid azo[1,2-a]pyridin-2-yl)propan-2-ol

[0637] The experimental procedure was the same as in Example 2, using 2-(6-bromo-7-methoxy[1,2-a]pyridin-2-yl)propan-2-ol (120 mg, 0.42 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (120 mg, 0.42 mmol) as starting materials to obtain the title compound (25 mg, 13%).

[0638] 1 H NMR (400 MHz, CHLOROFORM-d) 9.37 (s, 1H), 8.31 - 8.23 (m, 3H), 8.03 (s, 1H), 7.40 - 7.33 (m, 2H), 6.97 (s, 1H), 4.59 (q, J = 7.3 Hz, 2H), 3.86 (s, 3H), 1.71 - 1.67 (m, 9H). LC-MS: m / z [M+H] + = 447.

[0639] Example 58

[0640]

[0641] 58-1: 4-Bromo-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-fluoropyridine

[0642] (4-Bromo-2-fluoropyridin-3-yl)methanol (2.0 g, 9.71 mmol), tert-butyldimethylsilyl chloride (2.93 g, 19.42 mmol), and imidazole (1.32 g, 19.42 mmol) were added to dichloromethane (15 ml), and the mixture was stirred at room temperature for 30 minutes. The reaction solution was sampled and purified by column chromatography (petroleum ether / ethyl acetate = 20 / 1) to obtain the title compound as a colorless oily liquid (3.8 g, crude product). LC-MS: m / z [M+H] + = 320, 322.

[0643] 58-2: 4-Bromo-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-hydrazinopyridine

[0644] 4-Bromo-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-fluoropyridine (3.8 g, 11.86 mmol) and hydrazine hydrate (5.94 g, 118.6 mmol) were added to 1,4-dioxane (20 ml). The reaction was carried out at 80 °C for 2 hours. The reaction solution was sampled and purified by column chromatography (petroleum ether / ethyl acetate / ammonia water = 20 / 1 / 0.05) to obtain the title compound as a gray solid (2.1 g, 53%). LC-MS: m / z [M+H] + = 332, 334.

[0645] 58-3: 7-Bromo-8-(((tert-butyldimethylsilyl)oxy)methyl)-3-methyl-[1,2,4]triazolo [4,3-a]pyridine

[0646] 4-Bromo-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-hydrazinopyridine (1.03 g, 3.01 mmol) and 5M acetaldehyde in tetrahydrofuran solution (1.6 ml) were added to 1,4-dioxane (6 ml). The reaction was carried out at 80 °C for 1 hour. Copper(II) bromide (280 mg, 1.24 mmol) and potassium monopersulfate (2.29 g, 3.72 mmol) were added to the reaction solution, and the reaction was carried out at room temperature for 4 hours. The reaction solution was filtered by suction, sampled, and purified by column chromatography (dichloromethane / methanol = 30 / 1) to obtain the title compound as a white solid (262 mg, 23.54%). LC-MS: m / z [M+H] + = 356, 358.

[0647] 58-4: (7-Bromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)methanol

[0648] 7-Bromo-8-(((tert-butyldimethylsilyl)oxy)methyl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridine (260 mg, 0.61 mmol) was added to dichloromethane (10 ml). 4M hydrochloric acid in dioxane solution (2 ml) was added, and the mixture was stirred at room temperature for 20 minutes. The reaction solution was concentrated, sampled, and purified by column chromatography (dichloromethane / methanol = 20 / 1) to obtain the title compound as a brown solid (160 mg, 96%). LC-MS: m / z [M+H] + = 242, 244.

[0649] 58-5: 7-Bromo-8-(methoxymethyl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridine

[0650] (7-Bromo-3-methyl-[1,2,4]triazolo[4,3-a]pyridin-8-yl)methanol (160 mg, 0.66 mmol) was added to N,N-dimethylformamide (2 ml). Sodium hydride (52 mg, 1.32 mmol) was added to the reaction mixture, and the mixture was stirred at room temperature for 15 minutes. Iodomethane (190 mg, 1.31 mmol) was added to the reaction mixture, and the reaction was carried out at room temperature for 30 minutes. The reaction mixture was prepared for thin layer chromatography (dichloromethane / methanol = 20 / 1) to obtain the title compound (143 mg, 85%). LC-MS: m / z [M+H] + = 256, 258.

[0651] 58: 7-Ethyl-4-(4-fluoro-3-(8-(methoxymethyl)-3-methyl-[1,2,4]triazolo[4,3-a]pyridin- 7-yl)phenyl)-7H-imidazo[4,5-c]pyridazine

[0652] The experimental procedure was the same as in Example 1, using 7-bromo-3-methyl-8-(methoxymethyl)-[1,2,4]triazolo[4,3-a]pyridine (143 mg, 0.56 mmol) and (5-(7-ethyl-7H-imidazo[4,5-c]pyridazin-4-yl)-2-fluorophenyl)boronic acid (159 mg, 0.56 mmol) as starting materials to obtain the title compound as a brown solid (82 mg, 35%).

[0653] 1 H NMR (400 MHz, CHLOROFORM-d) 9.40 (s, 1H), 8.43 (d, J = 5.9 Hz, 2H), 8.28 (s, 1H), 7.89 (d, J = 7.3 Hz, 1H), 7.42 (t, J = 9.3 Hz, 1H), 6.95 (d, J = 6.8 Hz, 1H), 4.84 (s, 2H), 4.59 (q, J = 7.3 Hz, 2H), 3.41 (s, 3H), 2.81 (s, 3H), 1.70 (t, J = 7.3 Hz, 3H). LC-MS: m / z [M+H] + = 418.

[0654] Example 59

[0655]

[0656] 59-1: 3-Methoxybenzo[b]thiophene

[0657] 3-Bromobenzo[b]thiophene (500 mg, 2.35 mmol), sodium methoxide (1267 mg, 23.5 mmol), copper(II) oxide (93 mg, 1.18 mmol), copper(I) iodide (22 mg, 0.12 mmol), potassium iodide (19 mg, 0.12 mmol) were added to N,N-dimethylformamide (5 ml) and methanol (5 ml). The reaction was carried out in a sealed tube at 120 °C overnight. The reaction mixture was added to water (30 ml), extracted with ethyl acetate, the organic phases were combined, washed with saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, concentrated, and purified by column chromatography (pure petroleum ether) to give the title compound as a colorless oily liquid (308 mg, 80%). LC-MS: m / z [M+H] + = 165.

[0658] 59-2: 2-Bromo-3-methoxybenzo[b]thiophene

[0659] 3-Methoxybenzo[b]thiophene (308 mg, 1.88 mmol) and N-bromosuccinimide (368 mg, 2.07 mmol) were added to dichloromethane (5 ml). The mixture was stirred at 25 °C for 30 minutes. The reaction mixture was filtered by suction, concentrated, and purified by preparative thin-layer chromatography (pure petroleum ether) to give the title compound as a pink oily liquid (311 mg, 68%). 1 H NMR (400 MHz, CHLOROFORM-d) δ = 7.72 (d, J = 7.3 Hz, 1H), 7.66 (d, J = 7.8 Hz, 1H), 7.39 - 7.31 (m, 2H), 4.05 (s, 3H).

[0660] 59: 7-Ethyl-4-(4-fluoro-3-(3-methoxybenzo[b]thiophen-2-yl)phenyl)-7H-imidazo[4,5-c] pyridazine

[0661] 7-Ethyl-4-(4-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-7H-imidazo[4,5-c]pyridazine (59 mg, 0.16 mmol), 2-bromo-3-methoxybenzo[b]thiophene (97 mg, 0.4 mmol), cesium carbonate (104 mg, 0.32 mmol), and tetrakis(triphenylphosphine)palladium(0) (9 mg, 0.008 mmol) were added to 1,4-dioxane (2 ml) and water (0.2 ml). Under argon protection, the reaction was carried out at 100 °C for 4 hours. The reaction mixture was filtered by suction, concentrated, and purified by preparative thin-layer chromatography (petroleum ether / dichloromethane / methanol = 20 / 30 / 1) to give the title compound as a pale yellow solid (6 mg, 9%).

[0662] 11H NMR (400 MHz, CHLOROFORM-d) δ 9.43 (br.s., 1H), 8.68 (d, J = 5.4 Hz, 1H), 8.31 (br.s., 2H), 7.90 - 7.76 (m, 2H), 7.41 (br.s., 3H), 4.60 (d, J = 7.3 Hz, 2H), 3.93 (br.s., 3H), 1.70 (t, J = 6.4 Hz, 3H). LC-MS: m / z [M+H] + = 405.

[0663] Cell line construction and subculture

[0664] The α subunit, β subunit and γ subunit are essential for forming a complete functional GABA A receptor. In this example, the present invention constructs and separately screens HEK293 cells stably expressing human α1-GABA A receptor (α1-GABA A R) and α2-GABA A receptor (α2-GABA A R) by liposome transfection method (Felgner, P.L., et al. Proceedings of the National Academy of Sciences, 1987, 84: 7413 - 7417). The α1-GABA A R-HEK293 cell model simultaneously expresses the α1 subunit (protein sequence see GenBank accession number: NM_000806.5), β3 subunit (protein sequence see GenBank accession number: NM_000814.5) and γ2 subunit (protein sequence see GenBank accession number: NM_000816.3). The α2-GABA A R-HEK293 cell model simultaneously expresses the α2 subunit (protein sequence see GenBank accession number: NM_000807.4), β3 subunit (protein sequence see GenBank accession number: NM_000814.5) and γ2 subunit (protein sequence see GenBank accession number: NM_000816.3).

[0665] The above cell lines are subcultured. Expand α2-GABA A R-HEK293 cells for the benzodiazepine site (BZD) affinity test of the compound for the GABA A receptor. α1-GABA A R-HEK293 cells and α2-GABA ADuring the passage of R-HEK293 cells, some suspended cells were plated on glass slides pretreated with Poly-D-Lysine for electrophysiological tests (the method refers to paragraph 0586 of patent CN 107344936 A).

[0666] The compound of the present invention has an affinity activity for the α2-GABA A receptor

[0667] by competition 3 H-flunitrazepam (isotope 3 H-labeled flunitrazepam) binds to the BZD site of the membrane protein of stably expressed human α2-GABA A R-HEK293 cells to determine the affinity of the compound for the α2-GABA A receptor.

[0668] Membrane preparation: The cells were suspended in 50 mM Tris-HCl buffer (pH = 7.4), homogenized 10 times for 20 seconds with a homogenizer on ice, and centrifuged at 4°C, 1000g for 10 min. The supernatant was taken and the above steps were repeated. The supernatant was centrifuged at 4°C (33800g; Thermo, rotor: A27-8x50) for 60 min, and the precipitate was resuspended in Tris buffer (50 mM Tris-HCl, 10 mM MgCl2, 0.5 mM EDTA, 10% glycerol). The protein content was measured (BCA (bicinchoninic acid) protein quantification test method based on the copper ion reduction method, and the BCA kit was purchased from Pierce), 1 mL aliquots were prepared and stored at -80°C.

[0669] Radioactive ligand competition binding assay: This assay was carried out in a 200 μL system (96-well plate), which contained 100 μL of cell membrane. 3 The concentration of H-flunitrazepam was 1 nM, and the concentration of the compound to be tested was in the range of 1x10 -5 -10 -6Within the range of M. Using flumazenil as a control. 1 μL of 2 mM flumazenil (final concentration 10 μM) was added to the low signal control well (LC), and 1 μL of dimethyl sulfoxide was added to the high signal control well (HC). The final concentration of the target membrane protein was 5 μg / well. All test compound sample stocks were 10 mM dimethyl sulfoxide solutions. The working concentration of the samples was obtained by diluting all samples to 0.2 mM with dimethyl sulfoxide and then performing 4-fold serial dilutions for a total of 8 concentration gradients. The 96-well plate was sealed with a sealing film and then incubated on a shaker at room temperature for 1 hour. Meanwhile, the GF / C filter plate was soaked in the soaking buffer (0.3% PEI (polyethyleneimine, purchased from: sigmaaldrich, model: P314), stored at 4°C) for at least 0.5 hours. After the binding incubation was completed, the cells were collected onto the GF / C filter plate using a cell harvester and washed 4 times with the washing buffer (50 mM Tris-HCl, pH 7.4, stored at 4°C). After drying in an oven at 50°C for 1 hour, the bottom of the dried GF / C filter plate was sealed with a film, and the residual radioactivity on the filter membrane was detected by liquid scintillation counting. 50 μL of scintillation fluid was added to each well and sealed, and readings were taken using Microbeta 2 (Microplate counter, purchased from: PerkinElmer, model: CNLL0153). Calculate the inhibitory activity of the test samples against 3 H-flunitrazepam binding to the GABA A receptor membrane protein. Calculate the IC 50 of each test sample by dose-response curve fitting (GraphPad Prism 5 software), and calculate the Ki of the sample through IC 50 to evaluate the binding ability of the compound to the BZD site of the α2-GABA A receptor.

[0670] Representative test results obtained by the above method for determining the binding affinity of the compound to the BZD site of the human α2-GABA A R-HEK293 cell membrane protein are shown in Table 1.

[0671] The functional activity of the compounds of the present invention against different subtypes of GABA A receptors

[0672] The positive regulatory activity of the test drug against the α1-GABA A receptor and the α2-GABA A receptor was detected by electrophysiological methods. The specific method is as follows:

[0673] Compound concentration setting: The final concentration of the compounds used in compound screening is 100 nM. For cell lines expressing the α1-GABA A receptor, the GABA concentration is 0.05 - 0.07 μM (approx. EC 2～4 ); for cell lines expressing the α2-GABA A receptor, the GABA concentration is 0.10 - 0.11 μM (approx. EC 7～8 ). The electrophysiological experiment uses the whole-cell patch-clamp technique, and this method can refer to the method reported in the literature (Nickolls, S.A., et al. British Journal of Pharmacology, 2018, 175: 708–725). The composition of the extracellular solution (ECS) for electrophysiology is as follows: 150 mM NaCl, 5 mM KCl, 2.5 mM CaCl2, 1 mM MgCl2, 10 mM HEPES, and 10 mM glucose (pH 7.4); the formula of the intracellular solution (ICS) for electrophysiology is as follows: 140 mM CsCl, 11 mM EGTA, 10 mM HEPES, 2 mM CaCl2, 1 mM MgCl2, 4 mM MgATP, 2 mM TEA (pH 7.3). GABA (γ-aminobutyric acid) powder is prepared into a stock solution with pure water and then diluted in ECS; the compounds are first prepared into a 4 mM stock solution with dimethyl sulfoxide and then gradually diluted to the corresponding concentration in GABA-ECS. The solutions are freshly prepared before electrophysiological testing.

[0674] Electrophysiological signals are collected using an EPC 10 amplifier and PatchMaster software (HEKA) or an Axon 700B amplifier and Clampex software (AXON). The recording electrodes are pulled from borosilicate glass, and the electrode resistance is 4 - 6 MΩ. Extracellular drug administration uses an ALA-VC-8PG TM system. Select a single independently growing cell. After the glass electrode forms a good seal with the cell, the membrane is ruptured to form the whole-cell mode. The cell membrane potential is clamped at -60 mV and recorded in the Gap-free mode. During the experiment, first apply the extracellular solution for about 20 seconds outside the cell. After the baseline (I prebaseline ) is stable, switch the extracellular solution to GABA-ECS. At this time, the current (I gaba ) induced by GABA can be detected. After about 10 - 20 seconds, when the current is stable, switch the extracellular solution to the mixed solution of the compound and GABA-ECS until the current (I treatment ) jointly induced by the compound and GABA can be detected. Finally, switch the solution to the extracellular solution and record for 20 - 40 seconds to terminate the experiment. Only when the baseline is stable and the size of the control current (Igaba -I prebaseline ) Cells with an absolute value of current greater than 40 pA and relatively stable current within 10 - 20 seconds will be used for compound testing.

[0675] α1 - GABA A R and α2 - GABA A The experimental results of the positive allosteric regulatory activity of R were analyzed using PatchMaster v2x90.1 or PatchMaster v2x90.3 software (EPC 10 amplifier) and Clampex 10.6 software (Axon 700B amplifier). The current values at each stage were calculated as the average value of the current after stabilization under the corresponding conditions. We defined the control current as I gaba -I prebaseline , and the current after compound treatment was defined as I treatment -I prebaseline . The allosteric regulatory activity of the compound was expressed as a percentage and calculated according to the following formula: Functional activity = [(I treatment -I gaba ) / (I gaba -I prebaseline )] × 100%. If the value is negative, it indicates that the test compound has a negative allosteric regulatory effect on the GABA receptor. If the value is positive, it indicates that the test compound has a positive allosteric regulatory effect on the GABA receptor. For convenient comparison, the positive compound CVL - 865 was used as a reference for normalization, that is, positive allosteric regulatory activity = [functional activity of the compound / functional activity of the positive compound] × 100%. The test results of the positive allosteric regulatory activity of the compound on the α1 - GABA A receptor and α2 - GABA A receptor are shown in Table 1.

[0676] In vitro micronucleus test

[0677] 1. Guidelines for genotoxicity studies

[0678] This experimental design was based on the experimental purpose and followed the following experimental design guidelines:

[0679] (1) OECD Test Guideline 487, In vitro Mammalian Cell Micronucleus Test, revised in 2016;

[0680] (2) ICH S2(R1): Guidelines for Genotoxicity Testing and Results Analysis of Medicinal Products for Human Use, which came into effect in November 2011.

[0681] 2. Materials and methods

[0682] Experimental System and Reasons for Selection: In this experiment, Chinese hamster ovary cells (CHO-WBL cells) were used as the experimental system. The karyotype of this cell line contains 21 chromosomes, and its growth cycle is 12 to 13 hours. The CHO-WBL cells were originally derived from Dr. S. Wolff at the University of California, San Francisco, USA, and were later cloned in the laboratory of Dr. A. Bloom at Columbia University in New York. Subsequently, they were cloned again by Dr. S. Galloway at the Litton Bionetics laboratory in Maryland. The cell stock solution is stored in liquid nitrogen. The karyotype of each batch of cell stock solution has been identified and tested to prove that it is not contaminated with mycoplasma. The number of passages after cell cloning will not exceed 15 times. The reason for choosing Chinese hamster ovary cells is that this cell line is recommended in OECD Chemical Testing Guideline 487 and has been proven to be sensitive to many clastogens / aneugens (Marilyn J. et al., 2006).

[0683] Culture Medium and Cell Growth Conditions: Chinese hamster ovary cells were cultured in McCoy’s 5A complete medium (McCoy’s 5A complete medium supplemented with 10% (v / v) fetal bovine serum, 2 mM GlutaMAX TM medium, 100 units / mL penicillin, and 100 μg / mL streptomycin), and grew in a standard environment (a humidified incubator at 37 °C with a CO2 concentration of 5%). One day before drug administration, exponentially growing CHO-WBL cells were seeded onto eight-well cell culture slides at a density of 8 x 10 3 cells / 400 μL McCoy’s 5A complete medium / well.

[0684] Metabolic Activation System: The in vitro metabolic activation system (Maron and Ames, 1983) consists of β-naphthoflavone and phenobarbital-induced rat liver microsomal homogenate (abbreviated as S9) and a NADPH-generating system (i.e., sodium NADP plus trisodium isocitrate). S9 was purchased from Qisheng Biotechnology Co., Ltd. and stored in a -75 °C refrigerator before use. Preparation method of S9 homogenate: β-Naphthoflavone and phenobarbital were intraperitoneally injected into male Sprague Dawley rats once, and the tissues were taken for preparation.

[0685] Preparation of S9 Metabolic Activation System: First, dissolve sodium NADP and trisodium isocitrate in serum-free medium to make a core solution, and filter and sterilize it with a 0.22 μm filter head. Before use, thaw the S9 homogenate and mix the components of the S9 metabolic activation system according to the ratio shown in Table 2 below.

[0686] Table 2 Components and Ratios of S9 Metabolic Activation System

[0687]

[0688] Dose exploration experiment: In the dose exploration experiment, 8 dosing concentrations are set up in each dosing treatment series. One well of cells is set for each concentration of the test article. In the ICH guideline S2(R1), when not limited by the solubility of the test article in the solvent / media or the cytotoxicity of the test article, the recommended maximum concentration is 1 mM or 0.5 mg / mL, whichever is lower. However, if limited by solubility, the highest concentration tested is the lowest concentration at which a small amount of precipitate is visible in the medium under the microscope. To ensure that the solubility limit in the medium can be reached, up to 4 concentrations with visible precipitate can be tested.

[0689] Dosing treatment: In the 3-hour dosing series with S9 metabolic activation, the medium in each well is aspirated, and according to the ICH S2(R1) guideline, a serum-free McCoy’s 5A / S9 mixture medium containing the appropriate concentration of the test article / control is added.

[0690] In the 3-hour dosing series without metabolic activation, the medium in each well is aspirated, and McCoy’s 5A complete medium containing the appropriate concentration of the test article / control is added.

[0691] The cells are incubated under standard conditions for 3 hours. After 3 hours, the old medium in each well is aspirated, and the cells are washed twice with McCoy’s 5A complete medium. McCoy’s 5A complete medium containing cytochalasin B (final concentration in the medium is approximately 3 μg / mL) is added to each well, and then cultured for 21 hours until harvest.

[0692] For the 24-hour dosing series without metabolic activation, the treatment method is similar to that of the 3-hour dosing series without metabolic activation, except that the cells will be cultured with the test article / control in the complete medium containing cytochalasin B (final concentration in the medium is approximately 3 μg / mL) for 24 hours (±30 minutes).

[0693] Slide preparation: At harvest, the medium in the eight-well slides is poured out, blotted dry with absorbent paper, 75 mM KCl hypotonic solution is added to each well, and then the cells are fixed twice with the fixative (absolute methanol: glacial acetic acid, 3:1 v / v) for 5 minutes and air-dried. Stain with acridine orange and air-dry under light-proof conditions.

[0694] Count cytotoxicity: Examine the stained situation presented under a low-power microscope to evaluate the analyzability (sufficient number of cells) of all wells on each slide. Under a fluorescence microscope, at least 500 cells are analyzed in each well, and the numbers of mononuclear, binuclear, and multinuclear cells contained are counted separately to calculate the cytokinesis-block proliferation index (CBPI).

[0695] The cytotoxicity of the test substance was evaluated using CBPI. The calculation formula for CBPI is as follows:

[0696]

[0697] % Cytotoxicity = 100 - 100{(CBPIT - 1) / (CBPIC - 1)}

[0698] Where, T = treatment culture group with the test substance, C = vehicle control culture group.

[0699] When CBPI is 1, it is equal to 100% cytotoxicity.

[0700] Micronucleus main experiment: In the micronucleus main experiment, CHO-WBL cells were exposed to 3 - 8 concentrations of the test substance. At the same time, a positive control group (cyclophosphamide monohydrate) and a vehicle control group (dimethyl sulfoxide) with the same treatment as the solvent group were established. Each dose group had 2 wells of cells. In the non-activated test system, the dosing time was 3 and 24 hours. In the S9-activated test system, the exposure time of the test substance was 3 hours. The upper limit of the test substance test depends on its solubility in the culture medium, but generally does not exceed the maximum concentration of 1 mM or 0.5 mg / mL, taking the lower value. When selecting the highest dose for micronucleus frequency analysis, the cytotoxicity of this test substance dose group should not exceed 50% too much compared with the corresponding vehicle control group. If the highest concentration is not limited by cytotoxicity, in order to reach the solubility limit in the culture medium, multiple doses with visible precipitation can be tested, and there should be a small amount of recognizable precipitation visible in the culture medium of the highest dose group.

[0701] Selection of doses for micronucleus analysis: The selection of doses for micronucleus analysis of CHO-WBL cells will depend on the cytotoxicity of the test substance. The highest dose selected for evaluation will induce no more than 50% too much cytotoxicity. At least two lower dose groups should be analyzed additionally (in the range of moderate to non-cytotoxicity, if applicable). If the test substance has no cytotoxicity, then select the dose at which precipitation can be observed under the microscope at the end of dosing, or the maximum concentration to be tested (1 mM or 0.5 mg / mL, taking the lower value) as the highest concentration for micronucleus analysis.

[0702] Counting micronucleus frequency: All slides selected for micronucleus analysis were labeled with a randomly generated blind code to reduce the subjectivity of reading the slides. The blind code was made by personnel not involved in reading the slides. The label of the blindly labeled slides contained the following information: experiment number, treatment series, and random number.

[0703] For each dose group, 2000 binucleated cells (1000 per well) were analyzed to count the frequency of binucleated cells containing micronuclei.

[0704] Binucleated cells could be counted only if they met the following criteria:

[0705] a. Have a complete cell membrane. b. The two daughter nuclei are of equal size.

[0706] The criteria for judging micronuclei are as follows:

[0707] a. The micronuclei have a fluorescence intensity similar to that of the main nucleus. b. The micronuclei should be free in the cytoplasm. c. The micronuclei have a smooth edge and a diameter less than or equal to one-third of the diameter of the main nucleus.

[0708] The glass slides are discarded before signing the experimental report.

[0709] Data

[0710] Data report: The cytotoxicity of the dosing group is determined and presented based on the cytotoxicity compared to the corresponding vehicle control. The micronucleus frequency for each well and each dose group in the micronucleus main experiment is also presented.

[0711] Statistical analysis: Fisher's exact probability method is used to compare the significance of the difference in the frequency of binucleated cells containing micronuclei between the dosing group and the corresponding vehicle control group. When making multiple comparisons, the P-value is corrected by Bonferroni. When comparing multiple groups of data, the Cochran-Armitage test is used to detect the dose-effect relationship.

[0712] When P ≤ 0.05, the difference can be considered significant.

[0713] Experimental validity criteria: An acceptable genotoxicity test must meet the following criteria: The frequency of micronucleated cells in the vehicle / negative control must be comparable to the historical negative control data. There should be at least three concentrations that can be analyzed. The proportion of micronucleated cells in the positive control should show a statistically significant increase (p ≤ 0.05) compared to the parallel vehicle / negative control group.

[0714] Criteria for judging experimental results: On the premise that the experiment is valid, according to the guiding principle ICH S2(R1), for the determination of test results, it is necessary to combine the results of micronucleus rates under different dosing treatment conditions (administering with S9 for 3 hours, without S9 for 3 hours, without S9 for 24 hours) and different test substance concentrations, and refer to the criteria for judging test results to comprehensively analyze and determine that the in vitro micronucleus results of the test substance are negative, positive, or suspiciously positive. It is better to express the results as negative. The specific criteria for evaluating experimental results are as follows:

[0715] Positive: If the test substance simultaneously meets the following criteria, it can be considered positive: A significant increase in the frequency of micronucleated cells is observed in one or more dose groups compared to the parallel vehicle control group. The increase in micronucleus frequency shows a dose-effect relationship. The frequency of micronucleated cells is observed to exceed the range of the laboratory's negative historical data in one or more dose groups.

[0716] Negative: If none of the above three points are met, the test substance can be considered negative.

[0717] Suspicious positive: If a test substance only partially meets the above three points, a scientific judgment should be made. Signs of concentration-related effects are considered useful but not necessary when evaluating positive results. Biological relevance will be considered, such as the consistency of responses within and between concentrations, and (if applicable) the consistency of responses between experiments, or effects that occur only at high or extremely cytotoxic concentrations.

[0718] The compounds of the present invention on α2-GABA A receptor affinity and the positive allosteric modulation activity results on α1, α2-GABA A receptors are shown in Table 3 below, and the results of the in vitro micronucleus test are shown in Table 4.

[0719] It should be noted that since the advantage of the compounds described in the present invention lies in the high selectivity of the receptor rather than just the absolute activity of the drug, and considering that the absolute value of the functional activity of the compounds will vary to a certain extent under different detection systems and is not comparable, therefore, for the convenience of comparison, the experiments of the present invention synchronously detect the control and the compounds involved under the same detection system, and use the positive compound CVL-865 as a reference object for normalization, that is, the positive allosteric modulation activity = [functional activity of the compound / functional activity of the positive compound] × 100%, and the specific results are shown in Table 3 below.

[0720] Table 3 Affinity activity of some compounds on α2-GABA A receptor and positive allosteric modulation activity on α1, α2-GABA A receptors

[0721]

[0722]

[0723] The compounds of the examples of the present invention are compared with the reference compound CVL-865, with better selectivity. While maintaining an appropriate α2-GABA A receptor affinity and electrophysiological activity, the electrophysiological activity of the α1-GABA A receptor is less than 70% of CVL-865, so that while maintaining the in vivo drug efficacy, there are smaller side effects.

[0724] Table 4 Results of the in vitro micronucleus test

[0725]

[0726] It can be seen from the in vitro micronucleus results that the compounds of the present invention have better genetic toxicity safety and better drug-likeness.

[0727] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes or alterations derived therefrom still fall within the protection scope of the present invention.

Claims

1. A compound of formula (1) or a pharmaceutically acceptable salt thereof: Wherein, R2 is selected from H, halogen, OH, C1-C6 alkoxy or CN; R3 is selected from H, substituted or unsubstituted straight-chain or branched C1-C6 alkyl or substituted or unsubstituted C3-C6 cycloalkyl; the substitution means that one or more hydrogens on the group are substituted by alkyl selected from C1-C4, alkoxy selected from C1-C4, halogen-substituted alkyl selected from C1-C4 or halogen; R1 has a structure shown in formula (2), (3), (4), (5), (6) or (7): Wherein, R4 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C1-C6 alkylthio or C1-C6 alkylsulfonyl; the above groups may optionally be unsubstituted or independently of each other be substituted by at least one selected from halogen, hydroxy, C1-C3 alkyl, halogenated C1-C3 alkyl, C1-C3 alkoxy or halogenated C1-C3 alkoxy; R5 is selected from hydrogen, halogen, hydroxy, oxo, C1-C6 alkyl acyl, C1-C6 alkyl amide, C1-C6 alkoxy imino, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C6-C10 aryl, 5-10 membered heteroaryl containing 1-3 heteroatoms, C1-C6 non-aromatic heterocycle containing 1-3 heteroatoms; the above groups may optionally be unsubstituted or independently of each other be substituted by at least one selected from halogen, hydroxy, C1-C3 alkyl, halogen-substituted C1-C3 alkyl, C1-C3 alkoxy, halogenated C1-C3 alkoxy or 3-7 membered heterocycloalkyl containing 1-3 N or O heteroatoms; The A ring refers to a 5- to 7-membered saturated or partially unsaturated monocyclic ring containing N; m is 1, 2, or 3, and n is 1 or 2, indicating the connection site.

2. The compound according to claim 1, characterized in that, R4 is selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, methoxy, ethoxy, n-propoxy, -CH2-O-CH3, methylsulfonyl or ethylsulfonyl; the above groups may optionally be unsubstituted or independently of each other be substituted by C1-C3 alkoxy or halogen.

3. The compound according to claim 1, wherein R5 is selected from hydrogen, F, Cl, Br, hydroxy, formyl, acetyl, formamide, acetamide, methoxy imino, ethoxy imino, methyl, ethyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, phenyl, benzyl, tetrahydrofuran, tetrahydropyran, hexahydropyridine, oxetane, azetidine; the above groups may optionally be unsubstituted or independently of each other be substituted by at least one selected from F, Cl, Br, hydroxy, methoxy, methyl, pyrrolidine, morpholine or -CH2-CF3.

4. The compound according to claim 3, characterized in that, R5 is selected from H, methyl, ethyl, isopropyl, cyclopropyl, fluorocyclopropyl, or 5. The compound according to claim 1, characterized in that, The A ring is a 5-6 membered saturated or unsaturated monocyclic group containing 1, 2 or 3 N ring heteroatoms.

6. The compound according to claim 1, wherein When R1 has the structure shown in formula (2) or (7), the A ring has the following structure: Or When R1 has the structure shown in formula (3), (4), (5) or (6), the A ring has the following structure: or Among them, represents the connection site.

7. The compound according to any one of claims 1-6, characterized in that, R1 is selected from any one of the following structures: Or 8. The compound according to any one of claims 1-6, characterized in that, The R1 is selected from any one of the following structures: or And, R4 is selected from methoxy C1-C3 alkyl or C1-C3 alkoxy; R5 is selected from H, methyl, ethyl, isopropyl, cyclopropyl, fluorocyclopropyl, 9. The compound according to claim 8, wherein, R4 is methoxymethyl or methoxy.

10. The compound according to claim 1, wherein: R2 is selected from H or F; R3 is selected from H or a straight-chain or branched C1-C6 alkyl group.

11. The compound according to claim 1, characterized in that, The compound is selected from any one of the following compounds:

12. A pharmaceutical composition, characterized in that, It comprises the compound according to any one of claims 1-11 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or adjuvant are added.

13. The use of the compound according to any one of claims 1-11 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition according to claim 12, in the preparation of a medicament for treating or preventing a disease related to positive allosteric modulation of the α2-GABA A receptor.

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