PARP7 inhibitor and application thereof

Abstract

The invention relates to a compound which is shown in a formula (I), has a PARP7 inhibiting effect and is good in selectivity, pharmaceutically acceptable salt, stereoisomer, solvate or prodrug of the compound, application of the compound and a preparation method of the compound.

Description

Technical Field

[0001] This disclosure relates to the pharmaceutical field, and in particular to a compound with PARP7 inhibitory activity and good selectivity, its uses and preparation method. Background Technology

[0002] Poly-ADP-ribose polymerases (PARPs) are a family of proteins composed of 17 different members in the human body, each playing an important role in various biological processes, including inflammation, viral infection, and tumor cell stress. The PARP family can be divided into three categories based on catalytic activity: polyPARPs (4 members, including PARP1, PARP2, PARP5a, and PARP5b), monoPARPs (12 members, including PARP3, PARP4, PARP6, PARP7, PARP8, PARP9, PARP10, PARP11, PARP12, PARP14, PARP15, and PARP16), and non-catalytically active PARPs (1 member, PARP13). Most research on PARPs has focused on polyPARPs (PARP1, 2, 5a, and 5b), particularly the role of PARP1 / 2 in DNA damage repair. DNA damage refers to the permanent alteration of the DNA nucleotide sequence during DNA replication, leading to changes in genetic characteristics. If DNA damage or abnormal changes in genetic information cannot be corrected, it will affect cell function or survival. DNA damage repair is a programmed, orderly, multi-stage, and precise process involving multiple factors. PARP is an important protein in the DNA repair process, participating in a series of important cellular processes, including DNA repair and maintenance of genome stability. There are four PARP inhibitors available: niraparib and talazoparib target PARP1 and PARP2; olaparib and rucaparib target PARP1, PARP2, and PARP3. Olaparib (a first-in-class inhibitor), represented by the PARP1 / 2 inhibitor developed by AstraZeneca, has become a blockbuster drug with significant anti-cancer efficacy, and its indications can be gradually expanded through combination therapy.

[0003] Studies on monoPARPs targeting ADP-riboylation are relatively limited. As mentioned above, most members of the PARP family (12 in total) are monoPARPs. Recent research on monoPARPs has revealed that PARP7 plays an important role in immunity and cancer. Specifically, studies suggest that PARP7 is one of the target genes of AHR (anti-inflammatory neuropathy), and is part of a negative feedback loop regulating AHR activity. AHR can regulate immune function, inflammation, and play a role in cancer. It can be induced by cancer-related stresses, such as harmful chemicals in tobacco. In-depth studies on lung cancer, esophageal cancer, and head and neck cancer, which are strongly correlated with smoking, have revealed amplification and high expression of the gene locus where PARP7 is located. Research has found that PARP7 is overactive in tumor cells, and many cancer cells rely on PARP7 for cell survival. Studies have also shown that PARP7 can enable cancer cells to evade immune system attacks. Inhibiting PARP7 can effectively suppress cancer cell growth, restore interferon signaling, and reverse immunosuppression. In several cancer models, PARP7 inhibitors have shown durable tumor growth inhibition and interferon signaling restoration effects. In summary, PARP7 plays a crucial role in cancer and immune responses, making it a potentially ideal cancer target. However, earlier studies lacked selective chemical probes for PARP7, relying primarily on genetic methods to elucidate its function, thus failing to distinguish between enzymatic activity and the entire protein and its interactions. Furthermore, the lack of mature high-throughput on-target activity screening methods hindered the development of drugs targeting PARP7. Given the increasing number of PARP7-related research findings in recent years, PARP7 has become a more promising anti-cancer target. Currently, no PARP7 inhibitors have been approved for marketing, and Ribon's RBN-2397 has shown poor clinical efficacy. Additionally, studies have found that inhibiting PARP2 may cause hematologic toxicity.

[0004] Therefore, further research and development of new, safe, effective, and selective PARP7 inhibitors is of great significance. Furthermore, as mentioned above, in addition to its important role in tumors, PARP7 also plays a crucial role in diseases such as inflammation and viral infections. Therefore, besides its anti-cancer effects, PARP7 inhibitors are expected to have potential applications in other diseases such as inflammation, immunity, and viral infections. Summary of the Invention

[0005] The purpose of this invention is to provide a compound with PARP7 inhibitory activity and good selectivity, or a pharmaceutically acceptable salt, stereoisomer, solvate, or prodrug thereof.

[0006] In one aspect, the present invention provides a compound represented by formula (I), a pharmaceutically acceptable salt thereof, a stereoisomer thereof, a solvate thereof, or a prodrug thereof.

[0007]

[0008] In formula (I),

[0009] T1 is selected from CH, CR6, or N;

[0010] T2 is selected from CH, CR6, or N;

[0011] T6 is selected from CH, CR6, or N;

[0012] Y1 is selected from -NH-C 3-7 Cycloalkyl-, 3-10 nitrogen-containing heterocyclic alkyl groups containing at least one nitrogen atom, 5-6-membered heterocyclic aryl groups, 5-6-membered heterocyclic alkyl groups, -NHCH2-, -NHCH2CH2-;

[0013] T3 is selected from CH, CR5, or N;

[0014] T4 is selected from CH, CR5, or N;

[0015] T5 is selected from CH, CR5, or N;

[0016] The n1 R5 atoms may be the same or different from each other, where n1 is selected from 0, 1, 2, or 3, and R5 is selected from hydrogen, deuterium, -CF3, -CN, -OCH3, or...

[0017] R6 is selected from hydrogen, deuterium, -CN, -F, -Br, -CF3, -OCF3,

[0018] n2 is selected from 0 or 1;

[0019] T7 is selected from single bond, C, CH2. -O- or -OCH2-; preferably, T7 is selected from C, R7 is selected from hydrogen, deuterium, -CH3, -F, -CF3, R8 is selected from hydrogen, deuterium, -CH3, -F, -CF3, or R7 and R8 form a carbonyl group with the carbon atom they are connected to.

[0020] In a preferred embodiment, the compound of formula (I), its pharmaceutically acceptable salt, stereoisomer, solvate, or prodrug thereof, wherein the compound is selected from the group consisting of:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] In another aspect, the present invention provides a pharmaceutical composition, characterized in that the pharmaceutical composition comprises the above-described compound, a pharmaceutically acceptable salt thereof, a stereoisomer thereof, a solvate thereof or a prodrug thereof, and at least one pharmaceutically acceptable carrier.

[0028] In another aspect, the present invention provides the use of the above-described compound or a pharmaceutically acceptable salt, stereoisomer, solvate, prodrug thereof, or pharmaceutical composition as described above in the preparation of a PARP7 inhibitor or in the treatment of PARP7-mediated diseases.

[0029] Preferably, the PARP7-mediated diseases include cancer, immune diseases, inflammation, and viral infections;

[0030] Preferably, the cancer includes a solid tumor with PARP7 amplification;

[0031] Preferably, the solid tumors amplified by PARP7 include lung cancer, esophageal cancer, and head and neck cancer. Detailed Implementation

[0032] Based on the content of this disclosure, and in accordance with common technical knowledge and practices in the art, various other modifications, substitutions, or alterations can be made without departing from the basic technical ideas described in this disclosure.

[0033] I. Definition

[0034] The compounds disclosed herein may be asymmetric, for example, having one or more stereoisomers. Unless otherwise stated, all stereoisomers are included, such as enantiomers and diastereomers. The compounds containing asymmetric carbon atoms of this disclosure can be isolated in optically active pure form or in racemic form. The optically active pure form can be resolved from racemic mixtures or synthesized using chiral starting materials or chiral reagents. Racemic, diastereomer, and enantiomers are all included within the scope of this disclosure.

[0035] The disclosed compounds also include tautomer forms. Tautomer forms arise from the exchange of a single bond with an adjacent double bond, accompanied by the migration of a proton.

[0036] The term "substitution" refers to the replacement of one or more hydrogen atoms on a particular atom or group with a substituent, provided that the valence state of the atom or group is normal and the resulting compound is stable. When the substituent is a ketone group (i.e., =O), it means that two hydrogen atoms are replaced. Unless otherwise specified, the type and number of substituents can be arbitrary on the basis of chemical feasibility.

[0037] In this disclosure, when any variable (e.g., Rn) appears more than once in the composition or structure of a compound, its definition is independent in each case. Thus, for example, if a group is substituted by 1-5 Rs, the group may optionally be substituted by up to 5 Rs, and each R has an independent option. Furthermore, combinations of substituents and / or their variants are permitted only if such combinations produce a stable compound.

[0038] The term "alkyl" refers to a saturated aliphatic hydrocarbon group, which is a straight-chain or branched group containing 1 to 20 carbon atoms, preferably an alkyl group containing 1 to 8 carbon atoms, more preferably an alkyl group containing 1 to 6 carbon atoms, and most preferably an alkyl group containing 1 to 3 carbon atoms. Non-limiting examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, n-hexyl, 1-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2, 3-Dimethylpentyl, 2,4-Dimethylpentyl, 2,2-Dimethylpentyl, 3,3-Dimethylpentyl, 2-Ethylpentyl, 3-Ethylpentyl, n-Octyl, 2,3-Dimethylhexyl, 2,4-Dimethylhexyl, 2,5-Dimethylhexyl, 2,2-Dimethylhexyl, 3,3-Dimethylhexyl, 4,4-Dimethylhexyl, 2-Ethylhexyl, 3-Ethylhexyl, 4-Ethylhexyl, 2-Methyl-2-Ethylpentyl, 2-Methyl-3-Ethylpentyl, n-Nonyl, 2-Methyl-2-Ethylhexyl, 2-Methyl-3-Ethylhexyl, 2,2-Diethylpentyl, n-Decyl, 2,2-Diethylhexyl, 2,2-Diethylhexyl, and their various branched isomers, etc. More preferably, lower alkyl groups containing 1 to 6 carbon atoms are used. Non-limiting examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, n-hexyl, 1-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 2,2-dimethylbutyl, 1,3-dimethylbutyl, 2-ethylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, etc. The alkyl group can be substituted or unsubstituted. When substituted, the substituent can be substituted at any usable connection point. The substituent is preferably one or more of the following groups, independently selected from alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, mercapto, hydroxyl, nitro, cyano, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkoxy, heterocycloalkoxy, cycloalkylthio, heterocycloalkylthio, oxo, carboxyl, or carboxylic acid ester group. The present disclosure preferably includes methyl, ethyl, isopropyl, tert-butyl, haloalkyl, deuteralkyl, alkoxy-substituted alkyl, and hydroxy-substituted alkyl.

[0039] The term "cycloalkyl" refers to a saturated monocyclic alkane substituent, wherein the cycloalkyl ring contains at least 3 carbon atoms, preferably 3 to 12 carbon atoms, and more preferably 3 to 6 carbon atoms. Non-limiting examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.

[0040] The term "heterocyclic group" or "heterocyclic alkyl group" refers to a saturated monocyclic cyclic hydrocarbon substituent in which one or more ring atoms are heteroatoms selected from nitrogen, oxygen, or S(O)m (where m is an integer from 0 to 2), but excluding the ring moiety of -OO-, -OS-, or -SS-, and the remaining ring atoms are carbon. Non-limiting examples of heterocyclic groups include pyrrolidinyl, imidazolyl, tetrahydrofuranyl, tetrahydrothiophenel, dihydroimidazolyl, dihydrofuranyl, dihydropyrazolyl, dihydropyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, etc., preferably pyrrolidinyl, morpholinyl, piperidinyl, cycloheptyl, 1,4-diazacycloheptyl, and piperazinyl.

[0041] The heterocyclic group can be optionally substituted or unsubstituted. When substituted, the substituent is preferably one or more of the following groups, independently selected from alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, mercapto, cyano, nitro, chloro, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkoxy, heterocycloalkoxy, cycloalkylthio, heterocycloalkylthio, oxo, carboxyl, or carboxylic acid ester group.

[0042] The term "aryl" refers to a 6- to 14-membered all-carbon monocyclic or fused polycyclic (i.e., a ring sharing adjacent carbon atom pairs) group having a conjugated π-electron system, preferably 6- to 12-membered, such as phenyl and naphthyl. More preferably phenyl. The aryl ring may be fused to a heteroaryl, heterocyclic, or cycloalkyl ring, including benzo5- to 10-membered heteroaryl, benzo3- to 8-membered cycloalkyl, and benzo3- to 8-membered heteroalkyl, preferably benzo5- to 6-membered heteroaryl, benzo3- to 6-membered cycloalkyl, and benzo3- to 6-membered heteroalkyl, wherein the heterocyclic group is a heterocyclic group containing 1-3 nitrogen, oxygen, and sulfur atoms; or may further include a ternary nitrogen-containing fused ring containing a benzene ring.

[0043] The aryl group can be substituted or unsubstituted. When substituted, the substituent is preferably one or more of the following groups, independently selected from alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, mercapto, hydrogen, nitro, cyano, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkoxy, heterocycloalkoxy, cycloalkylthio, heterocycloalkylthio, carboxyl or carboxylic acid ester group.

[0044] The term "heteroaryl" refers to a heteroaryl system containing a heteroatom and a carbon atom, wherein the heteroatom is selected from oxygen, sulfur, and nitrogen. The heteroaryl group is preferably 5- or 6-membered, such as imidazolyl, furanyl, thiophene, thiazolyl, pyrazolyl, pyrroleyl, triazolyl, tetrazolyl, pyridinyl, pyrimidinyl, thiadiazole, pyrazinyl, etc., preferably triazolyl, thiophene, imidazolyl, pyrazolyl, oxazolyl, pyrimidinyl, or thiazolyl; more preferably pyrazolyl, pyrroleyl, and oxazolyl.

[0045] The heteroaryl group can be optionally substituted or unsubstituted. When substituted, the substituent is preferably one or more of the following groups, independently selected from alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, halogen, mercapto, hydrogen, nitro, cyano, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkoxy, heterocycloalkoxy, cycloalkylthio, heterocycloalkylthio, carboxyl, or carboxylic acid ester group.

[0046] In this disclosure,

[0047] DCM refers to dichloromethane;

[0048] Toluene or Tol refers to toluene;

[0049] Pd(PPh3)4 refers to tetra(triphenylphosphine)palladium;

[0050] Zn(CN)2 refers to zinc cyanide;

[0051] DMF stands for N,N-dimethylformamide;

[0052] ACN refers to acetonitrile;

[0053] Pd(dppf)Cl2 refers to 1,1-bis(diphenylphosphine)ferrocene palladium(II) chloride;

[0054] dioxane refers to 1,4-dioxane;

[0055] EtOH refers to ethanol;

[0056] NBS refers to N-bromosuccinimide;

[0057] AlBN refers to azobisisobutyronitrile (AIBN);

[0058] DBDMH refers to 1,3-dibromo-5,5-dimethylhydantoin;

[0059] NMP refers to N-methylpyrrolidone;

[0060] AcOH refers to acetic acid;

[0061] THF stands for tetrahydrofuran;

[0062] CHCl3 refers to chloroform;

[0063] n-BuLi refers to n-butyllithium;

[0064] BCl3 refers to boron trichloride;

[0065] EtOAc refers to ethyl acetate;

[0066] TEA stands for triethylamine;

[0067] MeOH refers to methanol;

[0068] HATU refers to 2-(7-azabenzotriazole)-N,N,N,N-tetramethylurea hexafluorophosphate;

[0069] DIEA refers to N,N-diisopropylethylamine.

[0070] All hydrogen atoms described in this disclosure can be replaced by their isotope deuterium.

[0071] In this disclosure, " "" refers to the point where chemical bonds are joined.

[0072] Drugs or drug compositions

[0073] The term "pharmaceutically acceptable" refers to those compounds, materials, compositions, and / or dosage forms that are suitable for use in human and animal tissues to the extent of reasonable medical judgment without excessive toxicity, irritation, allergic reactions, or other problems or complications in proportion to a reasonable benefit / risk ratio.

[0074] The term "pharmaceutically acceptable salt" refers to a salt that retains the biological potency of a particular compound as a free acid or base without any adverse biological effects. Examples include acid (including organic and inorganic acids) addition salts or base addition salts (including organic and inorganic bases).

[0075] The pharmaceutically acceptable salts disclosed herein can be synthesized from parent compounds containing an acid radical or a base using conventional chemical methods. Generally, such salts are prepared by reacting these compounds, in their free acid or base form, with a stoichiometric amount of a suitable base or acid in water or an organic solvent or a mixture thereof.

[0076] The pharmaceutical products or pharmaceutical compositions disclosed herein can be administered orally, topically, parenterally, or via mucosal routes (e.g., sublingually, by inhalation, or rectally) in dosage units comprising a conventional, non-toxic, pharmaceutically acceptable carrier. Oral administration is generally preferred. The active agent can be administered orally in capsule, tablet, or other similar forms (see Remington: The Science and Practice of Pharmacy, 20th Edition).

[0077] For oral administration in tablet or capsule form, the active pharmaceutical ingredient may be combined with non-toxic, pharmaceutically acceptable excipients such as binders (e.g., pregelatinized corn starch, polyvinylpyrrolidone, or hydroxypropyl methylcellulose); fillers (e.g., lactose, sucrose, glucose, mannitol, sorbitol, and other reducing and non-reducing sugars, microcrystalline cellulose, calcium sulfate, or calcium hydrogen phosphate); lubricants (e.g., magnesium stearate, talc or silica, stearic acid, sodium stearyl fumarate, glyceryl docosanoate, calcium stearate, etc.); disintegrants (e.g., potato starch or sodium hydroxyacetic acid starch); or wetting agents (e.g., sodium lauryl sulfate), colorants and flavorings, gelatin, sweeteners, natural and synthetic gums (e.g., gum arabic, tragacanth, or alginate), buffer salts, carboxymethyl cellulose, polyethylene glycol, waxes, etc. For oral administration in liquid form, the drug component may be combined with pharmaceutically acceptable inert carriers (e.g., ethanol, glycerol, water), anti-settling agents (e.g., sorbitol syrup, cellulose derivatives, or hydrogenated edible fats), emulsifiers (e.g., lecithin or gum arabic), non-aqueous carriers (e.g., almond oil, esters, ethanol, or fractionated vegetable oils), and preservatives (e.g., methylparaben, propylparaben, or sorbic acid). Stabilizers such as antioxidants (BHA, BHT, propyl iodide, sodium ascorbate, citric acid) may also be added to stabilize the dosage form.

[0078] Tablets containing the active compound can be coated using methods well known in the art. The compositions of this disclosure containing a compound of formula I as the active compound can also incorporate beads, microspheres, or microcapsules, for example, constructed from polyglycolic acid / lactic acid (PGLA). Liquid formulations for oral administration can take the form of, for example, solutions, syrups, emulsions, or suspensions, or they can be presented as dry products reconstituted with water or other suitable excipients prior to use. Formulations for oral administration can be suitably formulated to allow for controlled or delayed release of the active compound.

[0079] The pharmaceutical products or pharmaceutical compositions disclosed herein can be delivered parenterally, i.e., administered intravenously (IV), intraventricularly (ICV), subcutaneously (SC), intraperitoneally (IP), intramuscularly (IM), subcutaneously (SD), or intradermally (ID), by direct injection, such as rapid concentration or continuous infusion. Formulations for injection may be presented in unit dosage forms, such as in ampoules or multi-dose containers with added preservatives. The compositions may be in the form of excipients, suspensions, solutions, or emulsions in oil or aqueous carriers, and may contain formulation agents such as anti-settling agents, stabilizers, and / or dispersants. Alternatively, the active ingredient may be reconstituted in powder form with a suitable carrier (e.g., sterile, pyrogen-free water) prior to use.

[0080] The pharmaceutical or pharmaceutical composition disclosed herein can also be formulated for rectal administration, for example as a suppository or retention enema (e.g., containing a conventional suppository base such as cocoa butter or other glycerides).

[0081] The term "pharmaceutical composition" means a composition comprising the compounds described in this disclosure or their pharmaceutically acceptable salts, and at least one pharmaceutically acceptable ingredient selected from the following, depending on the manner of administration and the nature of the dosage form: carriers, diluents, adjuvants, excipients, preservatives, fillers, disintegrants, wetting agents, emulsifiers, suspending agents, sweeteners, flavoring agents, fragrances, antibacterial agents, antifungal agents, lubricants, dispersants, thermosensitive materials, temperature regulators, adhesives, stabilizers, suspending agents, etc.

[0082] II. Examples

[0083] The present disclosure is further illustrated below with reference to embodiments. The description of specific exemplary embodiments of the present disclosure is for illustrative and explanatory purposes. These descriptions are not intended to limit the present disclosure to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the teachings of this specification. The exemplary embodiments were chosen and described in order to explain the specific principles of the present disclosure and their practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the present disclosure, as well as various different choices and variations.

[0084] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0085] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0086] Experimental instruments and methods:

[0087] Instruments and reagents:

[0088] NMR measurements were performed using an Agilent 400MR DD2 NMR spectrometer. The solvents used were deuterated dimethyl sulfoxide (DMSO-D6), deuterated methanol (CD3OD), and deuterated chloroform (CDCl3). The internal standard was tetramethylsilane (TMS). LC-MS was performed using an Agilent 1260 Infinity II–InfinityLab LC / MSD mass spectrometer. HPLC was performed using an Agilent 1260 Infinity II high-performance liquid chromatograph (Sunfire C18 5μm 150x 4.6mm column). The reagents used are 6-bromo-4-iodonicotinic acid (Shanghai Bid Pharmaceutical Technology Co., Ltd.), 5-(di(adamantane-1-yl)phosphino)-1',3',5'-triphenyl-1'H-1,4'-bipyrazole (Adamas Reagents Co., Ltd.), 1-propynyl-tri-n-butyltin (Shaoyuan Technology Shanghai Co., Ltd.), tributyl(1-ethoxyethylene)tin (Shanghai Haohong Biomedical Technology Co., Ltd.), deuterated DMSO-D6 (Adamas Reagents Co., Ltd.), n-butyllithium, iodomethane, or synthesized using methods known in the art. Unless otherwise specified, all reactions in this disclosure are carried out under continuous magnetic stirring, under dry nitrogen or argon atmosphere, using dry solvents, and the reaction temperature is in degrees Celsius.

[0089] intermediate

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] Preparation of intermediate I-1: 6-bromo-4-bromomethylphthalazine-1(2H)-one (I-1)

[0098] Step 1: Preparation of methyl 2-acetyl-4-bromobenzoate (I-1-a)

[0099] Methyl 4-bromo-2-iodobenzoate (2 g, 5.87 mmol) was dissolved in tetrahydrofuran (20 ml), and nitrogen gas was introduced to replace the nitrogen atmosphere. After the reaction temperature was lowered to -78 °C, magnesium isopropyl chloride (3.22 ml, 6.54 mmol) was slowly added dropwise. After the reaction proceeded for 0.5 hours, acetic anhydride (778.5 mg, 7.63 mmol) was slowly added dropwise, and the reaction was continued with stirring at room temperature for 2 hours. After the reaction was complete, saturated ammonium chloride solution was added to quench the reaction, and the mixture was concentrated under reduced pressure. The solution was extracted three times with ethyl acetate and purified by Flash column chromatography (ethyl acetate: petroleum ether = 0–30%) to obtain methyl 2-acetyl-4-bromobenzoate (I-1-a, 429 mg, yield 28.58%), ESI [M+H). + =224.9, 226.9

[0100] Step 2: Preparation of 6-bromo-4-methylphthalazine-1(2H)-one (I-1-b)

[0101] Methyl 2-acetyl-4-bromobenzoate (I-1-a, 419 mg, 1.64 mmol) was dissolved in ethanol (6 mL), and hydrazine hydrate (5.8 mg, 0.177 mmol) was added. The mixture was reacted overnight at 85 °C. After monitoring the reaction to completion, the mixture was concentrated under reduced pressure, and the residue was washed with acetonitrile and filtered to give the target product, 6-bromo-4-methylphthalazine-1(2H)-one (I-1-b, 333 mg, yield 85.5%). ESI[M+H] + =240.1, 242.1

[0102] Step 3: Preparation of 6-bromo-4-bromomethylphthalazine-1(2H)-one (I-1)

[0103] 6-Bromo-4-methylphthalazin-1(2H)-one (I-1-b, 87.2 g mmol), N-bromosuccinimide (356 mg, 1.49 mmol), and azobisisobutyronitrile (25.6 mg, 0.149 mmol) were dissolved in acetonitrile (5 mL) and reacted overnight at 85 °C. After the reaction was complete, the reaction solution was filtered, and the filter cake was washed three times with acetonitrile and concentrated under reduced pressure to obtain the target product 6-bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 155 mg, yield 32.8%). ESI[M+H] + =318.2, 320.2

[0104] Preparation of intermediate I-2: 4-(bromomethyl)-6-cyclobutoxy-1-(2H)-one (I-2)

[0105]

[0106] Step 1: Preparation of methyl 2-acetyl-4-cyclobutoxybenzoate (I-2-a)

[0107] Methyl 2-acetyl-4-bromobenzoate (I-1-a, 300 mg, 1.17 mmol) was dissolved in toluene (8 mL), and cesium carbonate (764 mg, 2.34 mmol), cyclobutanol (275 μl, 3.52 mmol), palladium acetate (11.5 mg, 0.0469 mmol), and 5-(di(adamantane-1-yl)phosphino)-1',3',5'-triphenyl-1'H-1,4'-bipyrazole (62 mg, 0.0983 mmol) were added. The reaction mixture was reacted overnight at 100 °C under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 5:1) to obtain the target product, methyl 2-acetyl-4-cyclobutoxybenzoate (I-2-a, 68 mg, yield 23.3%). ESI [M+H] + =249.2

[0108] Step 2: Preparation of 6-cyclobutoxy-4-methylphthalazine-1(2H)-one (I-2-b)

[0109] Methyl 2-acetyl-4-cyclobutoxybenzoate (I-2-a, 68 mg, 0.274 mmol) was dissolved in ethanol (5 mL), and hydrazine hydrate (40 μl, 0.822 mmol) was added. The mixture was reacted overnight at 85 °C. The reaction solution was concentrated under reduced pressure and purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 6-cyclobutoxy-4-methylphthalazine-1(2H)-one (I-2-b, 72 mg, crude product). (ESI)[M+H] + =231.2

[0110] Step 3: Preparation of 4-(bromomethyl)-6-cyclobutoxy-1(2H)-one (I-2)

[0111] 6-Cyclobutoxy-4-methylphthalazin-1(2H)-one (I-2-b, 53 mg, 0.230 mmol) was dissolved in acetonitrile (2 ml), N-bromosuccinimide (82 mg, 0.461 mmol), and azobisisobutyronitrile (34 mg, 0.207 mmol). The mixture was reacted with microwave under reduced pressure for 1.5 h. The reaction solution was concentrated under reduced pressure and purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 1:1) to give the target product 4-(bromomethyl)-6-cyclobutoxy-1(2H)-one (I-2, 12 mg, yield 13.1%). ESI[M+H] + =309.1, 311.1

[0112] Preparation of intermediate I-3: 3-bromo-5-(bromomethyl)pyrido[2,3-d]pyridazin-8(7H)-one (I-3)

[0113]

[0114] Step 1: Methyl 5-bromo-3-iodopyridinecarboxylate (I-3-a)

[0115] Methyl 3-amino-5-bromopyridinecarboxylate (1 g, 4.33 mmol) was dissolved in an acetonitrile:water (1:2) mixture (15 ml). Under ice bath conditions, 12M hydrogen chloride solution (3.6 ml, 4.33 mmol) and sodium nitrite (600 mg, 8.7 mmol) aqueous solution (2 ml) were added dropwise. After stirring for 30 minutes, potassium iodide (2.16 g, 13 mmol) aqueous solution (4 ml) was added dropwise. Finally, the mixture was stirred at room temperature for 2 hours. After the reaction was complete, the reaction was quenched with sodium thiosulfate, and the mixture was extracted with ethyl acetate. The organic phase was collected, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by Flash column chromatography (petroleum ether:ethyl acetate = 3:1) to obtain the target product, methyl 5-bromo-3-iodopyridinecarboxylate (I-3-a, 1.48 g, 99% yield).

[0116] Step 2: Preparation of methyl 3-acetyl-5-bromopyridinecarboxylate (I-3-b)

[0117] Methyl 5-bromo-3-iodopyridinecarboxylate (I-3-a, 1.48 g, 4.3 mmol) was dissolved in dioxane (20 mL), and then tributyl(1-ethoxyethylene)tin (2.35 mL, 6.5 mmol) and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (0.32 g, 0.43 mmol) were added under stirring. After nitrogen purging, the mixture was heated to 100 °C and reacted overnight. After the reaction was completed, the mixture was cooled to room temperature, and 1 M hydrogen chloride solution was added to the reaction solution and stirred thoroughly for 10 minutes. The mixture was extracted with ethyl acetate, and the organic phase was collected and repeatedly washed with saturated sodium chloride solution. After drying with anhydrous sodium sulfate, the phase was filtered, concentrated under reduced pressure, and purified by Flash column chromatography (petroleum ether:ethyl acetate = 3:1) to obtain the target product, methyl 3-acetyl-5-bromopyridinecarboxylate (I-3-b, 580 mg, yield 51.92%). ESI [M+H] + =260.0

[0118] Step 3: Preparation of 3-bromo-5-methylpyridano[2,3-d]pyridazin-8(7H)-one (I-3-c)

[0119] Methyl 3-acetyl-5-bromopyridinecarboxylate (I-3-b, 580 mg, 2.25 mmol) was dissolved in ethanol (6 mL), and then hydrazine hydrate (0.146 mL, 2.92 mmol) was added with stirring. The mixture was heated to 70 °C and refluxed for 2 hours. After the reaction was complete, a large amount of solid precipitated. The reaction mixture was evaporated to dryness, slurried with a small amount of acetonitrile, filtered, and the solid on the filter cake was collected to obtain the target product 3-bromo-5-methylpyridano[2,3-d]pyridazin-8(7H)-one (I-3-c, 360 mg, yield 66.67%). ESI[M+H] + =239.9

[0120] Step 4: Preparation of 3-bromo-5-(bromomethyl)pyrido[2,3-d]pyridazin-8(7H)-one (I-3)

[0121] 3-Bromo-5-methylpyridano[2,3-d]pyridazin-8(7H)-one (I-3-c, 160 mg, 0.667 mmol) was dissolved in carbon trichloride (8 mL), followed by the addition of 1,3-dibromo-5,5-dimethylhydantoin (192 mg, 0.667 mmol) and azobisisobutyronitrile (56 mg, 0.667 mmol). The mixture was sealed and heated to 100 °C overnight. After the reaction was complete, the mixture was cooled to room temperature, and the filtrate was concentrated under reduced pressure using silica gel. The filtrate was then purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:2) to obtain the target product, 3-bromo-5-(bromomethyl)pyridano[2,3-d]pyridazin-8(7H)-one (I-3, 95 mg, yield 72%). ESI [M+H] + =319.9

[0122] Preparation of intermediate I-4: 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4)

[0123]

[0124] Step 1: Preparation of methyl 6-bromo-4-iodonicotinate (I-4-a)

[0125] 6-Bromo-4-iodonicotinic acid (500 mg, 1.52 mmol) was dissolved in N,N-dimethylformamide (6 ml), and potassium carbonate (316 mg, 2.287 mmol) and iodomethane (143 μl, 2.287 mmol) were added. The reaction was carried out overnight at room temperature. The reaction solution was quenched with water, extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure, and the crude product was purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product, methyl 6-bromo-4-iodonicotinic acid (I-4-a, 530 mg, crude product). (ESI)[M+H] + =342.2, 344.2

[0126] Step 2: Preparation of methyl 4-acetyl-6-bromonicotinic acid (I-4-b)

[0127] Methyl 6-bromo-4-iodonicotinate (I-4-a, 385 mg, 1.13 mmol) was dissolved in 1,4-dioxane (8 ml), and tributyl(1-ethoxyethylene)tin (612 μl, 1.69 mmol) and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (83 mg, 0.113 mmol) were added. The reaction was carried out overnight at 100°C under nitrogen protection. The reaction solution was quenched with water, extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure and dissolved in tetrahydrofuran (4 ml). 4M hydrochloric acid aqueous solution (4 ml) was added. After monitoring that the intermediate phase was completely consumed, the solution was concentrated under reduced pressure. The crude product was purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 3:1) to the target product methyl 4-acetyl-6-bromonicotinate (I-4-b, 270 mg, yield 49.6%).

[0128] Step 3: Preparation of 7-bromo-1-methylpyridano[3,4-d]pyridazin-4(3H)-one (I-4-c)

[0129] 4-Acetyl-6-bromonicotinic acid methyl ester (I-4-b, 270 mg, 1.05 mmol) was dissolved in ethanol (5 mL), and hydrazine hydrate (77 μl, 1.576 mmol) was added. The mixture was reacted at 70 °C for 1 hour. The reaction solution was concentrated under reduced pressure and purified by normal-phase column chromatography (petroleum ether: tetrahydrofuran = 1:1) to obtain the target product 7-bromo-1-methylpyridano[3,4-d]pyridazin-4(3H)-one (I-4-c, 228 mg, yield 90.87%). (ESI)[M+H + =240.1, 242.1

[0130] Step 4: Preparation of 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4)

[0131] 7-Bromo-1-methylpyrido[3,4-d]pyridazin-4(3H)-one (I-4-c, 120 mg, 0.502 mmol) was dissolved in chloroform (2 ml), and dibromohydantoin (143 mg, 0.502 mmol) and azobisisobutyronitrile (82 mg, 0.502 mmol) were added. The reaction mixture was reacted overnight at 100 °C. The reaction solution was concentrated under reduced pressure and purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4, 30 mg, yield 18.8%). (ESI)[M+H + =318.1, 320.1

[0132] Preparation of intermediate I-5: 6-bromo-4-bromomethyl-8-fluorophthalazine-1(2H)-one (I-5)

[0133]

[0134] Step 1: Preparation of methyl 4-bromo-2-fluoro-6-iodobenzoate (I-5-a)

[0135] Methyl 2-amino-4-bromo-6-fluorobenzoate (1 g, 4.03 mmol) was dissolved in a 1:2 mixture of acetonitrile and water (1:2) (12 mL). Under ice bath conditions, 3.4 mL (40 mmol) of 12 M aqueous hydrogen chloride solution and 556 mg (8.06 mmol) of sodium nitrite were slowly added dropwise. After 0.5 hours of reaction, 2 g (12.1 mmol) of potassium iodide was added in portions, and the reaction was continued with stirring at room temperature for 1 hour. After the reaction was complete, the mixture was quenched with saturated sodium thiosulfate solution, extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography (ethyl acetate: petroleum ether = 0–10%) to obtain methyl 4-bromo-2-fluoro-6-iodobenzoate (I-5-a, 1.29 g, yield 89.5%), ESI [M+H]. + =358.9

[0136] Step 2: Preparation of methyl 2-acetyl-4-bromo-6-fluorobenzoate (I-5-b)

[0137] Methyl 4-bromo-2-fluoro-6-iodobenzoate (I-5-a, 1.29 g, 3.6 mmol), tributyl(1-ethoxyethylene)tin (1.95 g, 5.4 mmol), and 1,1-bis(diphenylphosphine)ferrocene dichloropalladium(II) (263.8 mg, 0.36 mmol) were dissolved in 1,4-dioxane (30 ml) and reacted overnight at 85 °C under a nitrogen atmosphere. After the reaction was monitored and completed, the mixture was quenched with water, filtered through diatomaceous earth, concentrated under reduced pressure, and then dissolved in tetrahydrofuran (10 ml). A 10% hydrochloric acid solution was added and the mixture was stirred for 1 hour. The mixture was then extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and purified by Flash column chromatography (ethyl acetate: petroleum ether = 0–20%) to obtain the target product, methyl 2-acetyl-4-bromo-6-fluorobenzoate (I-5-b, 539 mg, yield 54.6%). ESI[M+H] + =275.6

[0138] Step 3: Preparation of 6-bromo-8-fluoro-4-methylphthalazine-1(2H)-one (I-5-c)

[0139] Methyl 2-acetyl-4-bromo-6-fluorobenzoate (I-5-b, 539 mg, 1.97 mmol) and hydrazine hydrate (118 μl, 2.36 mmol) were dissolved in ethanol (8 mL) and reacted at 70 °C for 1 hour. After the reaction was complete, the reaction solution was directly concentrated and purified by Flash column chromatography (tetrahydrofuran: petroleum ether = 0–50%) to give 6-bromo-8-fluoro-4-methylphthalazine-1(2H)-one (I-5-c, 106 mg, yield 21.1%). ESI[M+H] + =257.1, 259.1

[0140] Step 4: Preparation of 6-bromo-4-bromomethyl-8-fluorophthalazine-1(2H)-one (I-5)

[0141] 6-Bromo-8-fluoro-4-methylphthalazin-1(2H)-one (I-5-c, 106 mg, 0.414 mmol), N-bromosuccinimide (321.6 mg, 1.24 mmol), and azobisisobutyronitrile (81.6 mg, 0.497 mmol) were dissolved in acetonitrile (5 mL) and reacted by microwave at 100 °C for 1 hour. After the reaction was complete, the reaction solution was concentrated under reduced pressure, and the crude product was purified by thin-layer chromatography using silica gel (tetrahydrofuran: petroleum ether = 1:3) to obtain the product 6-bromo-4-bromomethyl-8-fluorophthalazin-1(2H)-one (I-5, 60.1 mg, yield 43.5%). ESI[M+H] + =337.1, 335.1

[0142] Preparation of intermediate I-6: 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6)

[0143]

[0144] Step 1: Preparation of tert-butyl 4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carboxylic acid (I-6-a)

[0145] 2-Chloro-5-(trifluoromethyl)pyrimidine (1825 mg, 10 mmol) was dissolved in N-methylpyrrolidone (30 mL), and piperazine-1-carboxylic acid tert-butyl ester (1862 mg, 10 mmol) and potassium carbonate (2764 mg, 20 mmol) were added. The mixture was reacted at 80 °C for 1 hour. Water (100 mL) was added, the solid was collected by filtration, and dried under vacuum to give the target product 4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-6-a, 2.9 g, yield 87%).

[0146] Step 2: Preparation of 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6)

[0147] 4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-6-a, 332 mg, 1 mmol) was dissolved in 4M ethyl acetate (5 mL) and reacted at room temperature for 2 hours. The reaction solution was filtered, and the solid was washed with petroleum ether to give the target product 2-(piperazine-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 289 mg, yield 94%). ESI[M+H] + =233.1 1 H NMR (400MHz, DMSO-d6) δ9.48(S,2H),8.78(S,2H),4.06(S,4H),3.18(S,4H).

[0148] Preparation of intermediate I-7: ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7)

[0149]

[0150] Step 1: Preparation of tert-butyl carbamate ((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (I-7-a)

[0151] Dissolve ((1R,3R)-3-((tert-butoxycarbonyl)amino)cyclobutane-1-carboxylic acid (1 g, 4.65 mmol) in N,N-dimethylformamide (10 ml), add O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (1.77 g, 4.65 mmol) and N,N-diisopropylethylamine (2.44 mL, 13.95 mmol) in an ice bath, stir for 30 minutes in an ice bath, and then add 2-(piperazine) (1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (1R,3R)-5-(trifluoromethyl)pyrimidin-1-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (1R,7-a, 1.7 g, yield 85.4%). The reaction mixture was reacted at room temperature for 3 hours, then added dropwise to water (100 mL) with stirring. The filter cake was concentrated under reduced pressure to obtain the target product ((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (1R,7-a, 1.7 g, yield 85.4%). (ESI)[M+H] + =430.2

[0152] Step 2: Preparation of ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7)

[0153] ((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)carbamate tert-butyl ester (I-7-a, 1.7 g, 3.96 mmol) was dissolved in ethyl acetate (10 mL), and 4M ethyl acetate hydrochloride solution (20 mL) was added under ice bath. After reacting at room temperature for 3 hours, the solution was concentrated under reduced pressure and then liberated with sodium bicarbonate to obtain the target product ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 1.6 g, crude product). (ESI)[M+H] + =330.2

[0154] Intermediate I-8: Preparation of tert-butyl 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (I-8)

[0155]

[0156] Step 1: Preparation of tert-butyl 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (I-8-a)

[0157] 1-(tert-Butoxycarbonyl)azacyclobutane-3-carboxylic acid (1 g, 4.97 mmol) was dissolved in dichloromethane (50 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (1.89 g, 4.97 mmol), N,N-diisopropylethylamine (2.6 mL, 14.91 mmol), and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 1.6 g, 5.96 mmol) were added. The reaction mixture was reacted at room temperature for 3 hours. The reaction solution was filtered, concentrated under reduced pressure, and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-8-a, 2.041 g, yield 98.86%). ESI[M+H-56] + =360.0ESI[2M+H] + =831.3

[0158] Step 2: Preparation of azirmonobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (I-8)

[0159] 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-8-a, 2.041 g, 4.91 mmol) was dissolved in ethyl acetate (20 mL), and a 4M solution of hydrogen chloride in ethyl acetate (4 mL) was slowly added dropwise (4 M) to the solution, and the mixture was stirred at room temperature for 4 hours. After concentration under reduced pressure, the product was liberated with sodium bicarbonate to obtain the target product, azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 1.9 g, purity 80.0%, crude product). ESI [M+H] + =316.1ESI[2M+H] + =631.4

[0160] Intermediate I-9: Preparation of (1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)(piperazin-1-yl)methyl ketone (I-9)

[0161]

[0162] Step 1: Preparation of tert-butyl ((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (I-9-a)

[0163] (1S,3S)-3-(tert-butoxycarbonylamino)cyclobutane-1-carboxylic acid (100 mg, 0.304 mmol), 2-(7-azabenzotriazole)-N,N,N,N-tetramethylurea hexafluorophosphate (181 mg, 0.476 mmol), and diisopropylethylamine (179.3 mg, 1.39 mmol) were dissolved in N,N-dimethylformamide (3 ml). Finally, 2-piperazin-1-yl-5-trifluoromethylpyrimidine hydrochloride (I-6, 127 mg, 0.472 mmol) was added, and the reaction was stirred overnight at room temperature. After the reaction was monitored to be complete, the reaction solution was added dropwise to ice water and stirred. The precipitated solid was filtered, the filter cake was collected, and finally concentrated under reduced pressure to obtain the target product, tert-butyl ((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (I-9-a, 190 mg, yield 95.4%). ESI[M+H] + =430.2

[0164] Step 2: Preparation of (1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)(piperazin-1-yl)methyl ketone (I-9)

[0165] Tert-butyl ((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)carbamate (I-9-a, 190 mg, 0.443 mmol) was dissolved in ethyl acetate solution of 4 mol / L hydrogen chloride and reacted overnight at room temperature. After the reaction was completed, the product was concentrated under reduced pressure and then purified by sodium bicarbonate to obtain the target product (1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)(piperazin-1-yl)methyl ketone hydrochloride (I-9, 200 mg, crude product). ESI[M+H] + =330.2 Intermediate I-10: Preparation of (R)-pyrrolidine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-10)

[0166]

[0167] Step 1: Preparation of (R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)pyrrolidine-1-carboxylic acid tert-butyl ester (I-10-a)

[0168] (R)-1-(tert-Butoxycarbonyl)pyrrolidine-3-carboxylic acid (100 mg, 0.465 mmol) was dissolved in N,N-dimethylformamide (6 ml). O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (176.7 mg, 0.465 mmol) and N,N-diisopropylethylamine (244 μl, 1.39 mmol) were added under ice bath conditions. After stirring for 30 minutes under ice bath conditions, 2- (piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 124 mg, 0.465 mmol) was reacted at room temperature for 3 hours. The reaction mixture was then added dropwise to water (12 mL) with stirring. After filtration, the filter cake was concentrated under reduced pressure to obtain the target product (R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidine-1-carboxylic acid tert-butyl ester (I-10-a, 130 mg, yield 65.2%). (ESI)[M-56+H] + =374.4

[0169] Step 2: Preparation of (R)-pyrrolidine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-10) Tert-butyl (R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidine-1-carboxylic acid (I-10-a, 130 mg, 0.303 mmol) was dissolved in 3 ml of 4 mol / L hydrogen chloride in ethyl acetate solution and reacted at room temperature for 2 hours. After the reaction was monitored to be complete, the solution was concentrated under reduced pressure and then purified by sodium bicarbonate to obtain the crude product (R)-pyrrolidine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-10, 137 mg). ESI [M+H] + =330.2ESI[2M+H] + =659.5

[0170] Preparation of intermediate I-11: 6-bromo-4-(bromomethyl)-7-fluorophthalazine-1(2H)-one (I-11)

[0171]

[0172] Step 1: Preparation of methyl 4-bromo-5-fluoro-2-iodobenzoate (I-11-a)

[0173] Methyl 2-amino-4-bromo-5-fluorobenzoate (1350 mg, 5.44 mmol) was dissolved in a 1:2 mixture of acetonitrile and water (30 mL). A 12 M aqueous solution of hydrogen chloride (4.53 mL, 54.42 mmol) and sodium nitrite (750 mg, 1087 mmol) were slowly added dropwise under ice bath conditions. After 0.5 hours of reaction, potassium iodide (2710 mg, 16.33 mmol) was added in portions, and the reaction was continued with stirring at room temperature for 2 hours. After the reaction was complete, the mixture was quenched with saturated sodium thiosulfate solution, extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and purified by Flash column chromatography (petroleum ether:ethyl acetate = 0–10%) to obtain the target product, methyl 4-bromo-5-fluoro-2-iodobenzoate (I-11-a, 1.24 g, yield 63.68%). ESI [M+H] + =359.1,361.1

[0174] Step 2: Preparation of methyl 2-acetyl-4-bromo-5-fluorobenzoate (I-11-b)

[0175] Methyl 4-bromo-5-fluoro-2-iodobenzoate (I-11-a, 1.24 g, 3.47 mmol), tributyl(1-ethoxyethylene)tin (1.88 g, 5.2 mmol), and 1,1-bis(diphenylphosphine)ferrocene palladium(II) chloride (254 mg, 0.35 mmol) were dissolved in 1,4-dioxane (40 mL) and reacted overnight at 100 °C under nitrogen. After the reaction was completed, the mixture was quenched with water, filtered through diatomaceous earth, concentrated under reduced pressure, and then dissolved in tetrahydrofuran (10 mL). A 10% hydrochloric acid solution was added and the mixture was stirred for 1 hour. The mixture was then extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and purified by Flash column chromatography (ethyl acetate: petroleum ether = 1:4) to obtain the target product, methyl 2-acetyl-4-bromo-5-fluorobenzoate (I-11-b, 540 mg, yield 56.65%).

[0176] Step 3: Preparation of 6-bromo-7-fluoro-4-methyldiazanaphth-1(2H)-one (I-11-c)

[0177] Methyl 2-acetyl-4-bromo-5-fluorobenzoate (I-11-b, 540 mg, 1.96 mmol) and hydrazine hydrate (149 μL, 2.35 mmol) were dissolved in ethanol (10 mL) and reacted at 70 °C for 1 hour. After the reaction was complete, the reaction solution was directly concentrated and purified by Flash column chromatography (tetrahydrofuran: petroleum ether = 1:1) to obtain the target product 6-bromo-7-fluoro-4-methyldiazanaphthyl-1(2H)-one (I-11-c, 160 mg, yield 31.71%). ESI[M+H] + =257.0,258.9

[0178] Step 4: Preparation of 6-bromo-4-(bromomethyl)-7-fluorophthalazine-1(2H)-one (I-11)

[0179] 6-Bromo-7-fluoro-4-methyldiazanaphthyl-1(2H)-one (I-11-c, 120 mg, 0.47 mmol), N-bromosuccinimide (208 mg, 1.17 mmol), and azobisisobutyronitrile (85 mg, 0.52 mmol) were dissolved in acetonitrile (8 mL) and reacted at 100 °C under microwave conditions for 1 hour. After the reaction was complete, the reaction solution was directly concentrated and purified by thin-layer chromatography on silica gel plates (tetrahydrofuran: petroleum ether = 1:3) to obtain the target product 6-bromo-4-(bromomethyl)-7-fluorophthalazine-1(2H)-one (I-11, 50 mg, yield 32.1%). ESI [M+H] + =335.1,337.1

[0180] Preparation of intermediate I-12: 4-(bromomethyl)pyrido[3,4-d]pyridazin-1(2H)-one (I-12)

[0181]

[0182] Step 1: Preparation of methyl 3-acetylisonicotinic acid (I-12-a)

[0183] 3-Iodoisonicotin methyl ester (1 g, 3.8 mmol), tributyl(1-ethoxyethylene)tin (2.06 mL, 5.7 mmol), and 1,1-bis(diphenylphosphine)ferrocene palladium(II) dichloride (280 mg, 0.38 mmol) were dissolved in 1,4-dioxane (15 mL) and reacted overnight at 100 °C under nitrogen. After the reaction was completed, the reaction solution was concentrated and purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain an intermediate compound. The organic phase was concentrated under reduced pressure and then dissolved in tetrahydrofuran (10 mL). 10% hydrochloric acid solution was added and the mixture was stirred for 1 hour. The pH was adjusted to 8 by adding saturated sodium bicarbonate solution. The mixture was extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, and filtered to obtain the target product, 3-acetylisonicotinic acid methyl ester (I-12-a, 535 mg, yield 78.7%). ESI[M+H] + =180.9

[0184] Step 2: Preparation of 4-methylpyridinone [3,4-d]pyridazine-1(2H)-one (I-12-b)

[0185] 3-Acetylisonicotinic acid methyl ester (I-12-a, 535 mg, 2.99 mmol) was dissolved in ethanol (10 mL), and hydrazine hydrate (179 μL, 3.58 mmol) was added. The reaction was carried out at 70 °C for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 4-methylpyridinone [3,4-d]pyridazine-1(2H)-one (I-12-b, 370 mg, yield 77.08%). ESI [M+H] + =161.9

[0186] Step 3: Preparation of 4-(bromomethyl)pyrido[3,4-d]pyridazin-1(2H)-one (I-12)

[0187] 4-Methylpyridinone[3,4-d]pyridazin-1(2H)-one (I-12-b, 315 mg, 1.96 mmol) was dissolved in chloroform (5 mL), and 1,3-dibromo-5,5-dimethylhydantoin (840 mg, 2.93 mmol) and azobisisobutyronitrile (322 mg, 1.96 mmol) were added. The reaction mixture was reacted overnight at 100 °C. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product 4-(bromomethyl)pyrido[3,4-d]pyridazin-1(2H)-one (I-12, 390 mg, purity 55%, yield 45.7%). ESI[M+H] + =239.5,241.6

[0188] Preparation of intermediate I-13: N-(2-(piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (I-13)

[0189]

[0190] Step 1: Preparation of tert-butyl 4-(3-nitro-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-13-a)

[0191] 2-Bromo-3-nitro-5-(trifluoromethyl)pyridine (100 mg, 0.369 mmol) and piperazine-1-carboxylic acid tert-butyl ester (76 mg, 0.406 mmol) were dissolved in N-methylpyrrolidone (3 mL), and potassium carbonate (153 mg, 1.107 mmol) was added. The reaction was carried out at 80 °C for 1 hour. The reaction solution was quenched with water, and the mixture was extracted with ethyl acetate. The organic phases were combined, washed with brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to obtain the target product, 4-(3-nitro-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-13-a, 120 mg, yield 86.41%). ESI[M+H-Boc] + =277.0, ESI[M+H-56] + =321.3

[0192] Step 2: Preparation of tert-butyl 4-(3-amino-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-13-b)

[0193] 4-(3-nitro-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-13-a, 120 mg, 0.319 mmol) and iron powder (356 mg, 6.377 mmol) were added to acetic acid (4 mL) and reacted at 80 °C for 2 hours. The reaction solution was cooled and filtered. The filtrate was concentrated under reduced pressure to obtain the target product, 4-(3-amino-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-13-b, 110 mg, yield 99.61%). ESI[M+H] + =347.9

[0194] Step 3: Preparation of N-(2-(piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (I-13)

[0195] 4-(3-amino-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-13-b, 110 mg, 0.318 mmol) and potassium carbonate (132 mg, 0.953 mmol) were added to N,N-dimethylformamide (3 mL). Acetyl chloride (37 mg, 0.476 mmol) was added dropwise under nitrogen protection, and the reaction mixture was heated to 100 °C for 2 hours. The reaction solution was cooled and quenched with water, then extracted with ethyl acetate. The organic phases were combined, washed with brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to obtain the target product, N-(2-(piperazine-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (I-13, 400 mg, purity 25%, yield 109.23%). ESI [M+H] + =289.1

[0196] Preparation of intermediate I-14: 4-(bromomethyl)-6-(trifluoromethyl)phthalazine-1(2H)-one (I-14)

[0197]

[0198] Step 1: Preparation of methyl 2-(1-ethoxyvinyl)-4-(trifluoromethyl)benzoate (I-14-a)

[0199] Methyl 2-bromo-4-(trifluoromethyl)benzoate (1 g, 3.53 mmol) was dissolved in 1,4-dioxane (20 mL), and then tributyl(1-ethoxyethylene)tin (1.91 g, 5.3 mmol) and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (259 mg, 0.353 mmol) were added under stirring. After nitrogen purging, the mixture was heated to 100 °C and reacted overnight. After the reaction was completed, the mixture was cooled to room temperature, and water was added. The mixture was then extracted with ethyl acetate. The organic phase was collected and repeatedly washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the target product, methyl 2-(1-ethoxyethylene)-4-(trifluoromethyl)benzoate (I-14-a, 1.41 g, crude product).

[0200] Step 2: Preparation of methyl 2-acetyl-4-(trifluoromethyl)benzoate (I-14-b)

[0201] Methyl 2-(1-ethoxyvinyl)-4-(trifluoromethyl)benzoate (I-14-a, 1.41 g, 5.14 mmol) was dissolved in tetrahydrofuran (15 mL), and 4M hydrochloric acid aqueous solution (5 mL) was added. The reaction was carried out at room temperature for 1 hour. After the reaction was completed, the product methyl 2-acetyl-4-(trifluoromethyl)benzoate (I-14-b, 1.42 g, crude product) was obtained by concentration under reduced pressure. ESI [M+H] + =246.6

[0202] Step 3: Preparation of 4-methyl-6-(trifluoromethyl)phthalazine-1(2H)-one (I-14-c)

[0203] Methyl 2-acetyl-4-(trifluoromethyl)benzoate (I-14-b, 1.42 g, 5.37 mmol) was dissolved in ethanol (20 mL), and then hydrazine hydrate (0.42 mL, 6.45 mmol) was added with stirring. The mixture was heated to 80 °C and refluxed for 1 hour. After the reaction was completed, the mixture was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:2) to obtain the target product 4-methyl-6-(trifluoromethyl)phthalazine-1(2H)-one (I-14-c, 500 mg, yield 37.99%). ESI [M+H] + =228.9

[0204] Step 4: Preparation of 4-(bromomethyl)-6-(trifluoromethyl)phthalazine-1(2H)-one (I-14)

[0205] 4-Methyl-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14-c, 400 mg, 1.75 mmol) was dissolved in carbon trichloride (15 mL), followed by the addition of 1,3-dibromo-5,5-dimethylhydantoin (500 mg, 1.75 mmol) and azobisisobutyronitrile (288 mg, 1.75 mmol). The mixture was sealed and heated to 100 °C overnight. After the reaction, the mixture was cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure using silica gel, and then purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:2) to obtain the target product, 4-(bromomethyl)-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14, 68 mg, yield 12.64%). ESI [M+H] + =306.8,308.7

[0206] Preparation of intermediate I-15: 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-15)

[0207]

[0208] Step 1: Preparation of 4-(2-(benzyloxy)acetyl)-6-bromonicotinic acid (I-15-a)

[0209] Under nitrogen protection, 2.1 mL (5.1 mmol) of n-butyllithium was slowly added dropwise to a 10 mL solution of tetrahydrofuran (0.85 mL (5.1 mmol) at -78 °C. The mixture was then heated to 0 °C and slowly cooled to -78 °C. A 2 mL solution of tetrahydrofuran containing 200 mg (1.27 mmol) of 6-bromonicotinic acid was slowly added dropwise to the above reaction mixture. The mixture was stirred at this temperature for 1.5 hours. Then, 0.96 mL (5.1 mmol) of 2-(benzyloxy)-N-methoxy-N-methylacetamide was added dropwise. After the addition was complete, the mixture was heated to -30 °C and stirred for 4 hours. After the reaction was complete, the reaction solution was quenched with 10% citric acid solution, extracted with ethyl acetate, washed with saturated brine of the organic phase, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. The crude product was purified by Flash column chromatography (petroleum ether:ethyl acetate = 0–70%) to obtain the target product 4-(2-(benzyloxy)acetyl)-6-bromonicotinic acid (I-15-a, 300 mg, yield 67.7%). ESI[M+H] + =349.7,351.8

[0210] Step 2: Preparation of 1-(benzyloxy)methyl)-7-bromopyrido[3,4-d]pyridazin-4(3H)-one (I-15-b)

[0211] 4-(2-(benzyloxy)acetyl)-6-bromonicotinic acid (I-15-a, 300 mg, 0.86 mmol) was dissolved in ethanol (5 mL), and hydrazine hydrate (52 μL, 1.03 mmol) was added. The reaction was carried out at 70 °C for 0.5 h. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 0–20%) to obtain the target product 1-(benzyloxy)methyl)-7-bromopyrido[3,4-d]pyridazine-4(3H)-one (I-15-b, 150 mg, yield 50.5%). ESI[M+H + =346.1,348.2

[0212] Step 3: Preparation of 7-bromo-1-(hydroxymethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-15-c)

[0213] 1-(benzyloxy)methyl)-7-bromopyrido[3,4-d]pyridazin-4(3H)-one (I-15-b, 150 mg, 0.43 mmol) was dissolved in dichloromethane (6 mL), and boron trichloride (0.65 mL, 0.65 mmol) was added at 0 °C. The reaction was carried out at this temperature for 2 hours. After the reaction was completed, saturated sodium bicarbonate solution was added at 0 °C to adjust the pH to alkaline. After stirring for 1 hour, the solution was concentrated to obtain a crude product. The crude product was purified by Flash column chromatography (dichloromethane:methanol = 0–10%) to obtain the target product 7-bromo-1-(hydroxymethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-15-c, 40 mg, yield 36.5%). ESI[M+H] + =256.3,258.2

[0214] Step 4: Preparation of 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-15)

[0215] 7-Bromo-1-(hydroxymethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-15-c, 40 mg, 0.157 mmol) was dissolved in ethyl acetate (5 mL) and manganese dioxide (136 mg, 1.57 mmol) was added. The mixture was reacted overnight at 70 °C. After the reaction was complete, the reaction solution was filtered while hot to obtain the target product, 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 33 mg, crude product). ESI[M+H] + =254.2,256.3 1 H NMR (600MHz, DMSO-d6) δ13.93(s,1H),9.80(s,1H),9.25(s,1H),8.79(s,1H).

[0216] Preparation of intermediate I-16: 4-(bromomethyl)-6-(trifluoromethoxy)phthalazine-1(2H)-one (I-16)

[0217]

[0218] Step 1: Preparation of methyl 2-bromo-4-(trifluoromethoxy)benzoate (I-16-a)

[0219] 2-Bromo-4-(trifluoromethoxy)benzoic acid (945 mg, 3.32 mmol) was dissolved in N,N-dimethylformamide (20 mL), potassium carbonate (1.37 g, 9.95 mmol) and iodomethane (413 μL, 6.63 mmol) were added, and the mixture was reacted overnight at room temperature. The reaction solution was quenched with water, extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 10:1) to obtain the target product, methyl 2-bromo-4-(trifluoromethoxy)benzoate (I-16-a, 1.091 g, yield 99.50%).

[0220] Step 2: Preparation of methyl 2-(1-ethoxyvinyl)-4-(trifluoromethoxy)benzoate (I-16-b)

[0221] Methyl 2-bromo-4-(trifluoromethoxy)benzoate (I-16-a, 1.091 g, 3.65 mmol) was dissolved in 1,4-dioxane (20 mL), and tributyl(1-ethoxyethylene)tin (1.97 g, 5.47 mmol) and [1,1'-bis(diphenylphosphine)ferrocene]palladium dichloride (267 mg, 0.365 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether:ethyl acetate = 10:1) to obtain the target product, methyl 2-(1-ethoxyvinyl)-4-(trifluoromethoxy)benzoate (I-16-b, 1.08 g, yield 101.99%). ESI [M+H] + =290.8

[0222] Step 3: Preparation of methyl 2-acetyl-4-(trifluoromethoxy)benzoate (I-16-c)

[0223] Methyl 2-(1-ethoxyvinyl)-4-(trifluoromethoxy)benzoate (I-16-b, 1.08 g, 3.72 mmol) was dissolved in tetrahydrofuran (12 mL), and 4M hydrochloric acid aqueous solution (3 mL) was added. The reaction was carried out at room temperature for 1 hour. After the reaction was completed, the solution was concentrated under reduced pressure to obtain the target product, methyl 2-acetyl-4-(trifluoromethoxy)benzoate (I-16-c, 1.06 g, crude product). ESI [M+H] +=262.8

[0224] Step 4: Preparation of 4-methyl-6-(trifluoromethoxy)phthalazine-1(2H)-one (I-16-d)

[0225] Methyl 2-acetyl-4-(trifluoromethoxy)benzoate (I-16-c, 1.06 g, 4.05 mmol) was dissolved in ethanol (15 mL), and hydrazine hydrate (243 mg, 4.85 mmol) was added. The mixture was reacted at 80 °C for 1.5 h. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 4-methyl-6-(trifluoromethoxy)phthalazine-1(2H)-one (I-16-d, 617 mg, yield 62.51%). ESI[M+H] + =244.7

[0226] Step 4: Preparation of 4-(bromomethyl)-6-(trifluoromethoxy)phthalazine-1(2H)-one (I-16)

[0227] 4-Methyl-6-(trifluoromethoxy)phthalazin-1(2H)-one (I-16-d, 617 mg, 2.53 mmol) was dissolved in chloroform (20 mL), and 1,3-dibromo-5,5-dimethylhydantoin (722 mg, 2.53 mmol) and azobisisobutyronitrile (415 mg, 2.53 mmol) were added. The reaction mixture was reacted overnight at 100 °C. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 2:1) to obtain the target product 4-(bromomethyl)-6-(trifluoromethoxy)phthalazin-1(2H)-one (I-16, 205 mg, yield 25.12%). ESI [M+H] + =322.9,324.7

[0228] Preparation of intermediate I-17: 7-cyclobutoxy-4-oxo-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-17)

[0229]

[0230] Step 1: Preparation of 1-(benzyloxy)methyl)-7-cyclobutoxypyrido[3,4-d]pyridazine-4(3H)-one (I-17-a)

[0231] 1-(benzyloxy)methyl)-7-bromopyrido[3,4-d]pyridazin-4(3H)-one (I-15-b, 160 mg, 0.464 mmol) was dissolved in 1,4-dioxane (4 mL), and cesium carbonate (302 mg, 0.928 mmol), cyclobutanol (218 μL, 7.28 mmol), palladium acetate (9.1 mg, 0.0371 mmol), and 5-(di(adamantane-1-yl)phosphino)-1',3',5'-triphenyl-1'H-1,4'-bipyrazole (49.2 mg, 0.0742 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product 1-(benzyloxy)methyl)-7-cyclobutoxypyridano[3,4-d]pyridazine-4(3H)-one (I-17-a, 126 mg, yield 80.76%). ESI[M+H + =338.2

[0232] Step 2: Preparation of 7-cyclobutoxy-1-(hydroxymethyl)pyrido[3,4-d]pyridazine-4(3H)-one (I-17-b)

[0233] 1-(benzyloxy)methyl)-7-cyclobutoxypyrido[3,4-d]pyridazin-4(3H)-one (I-17-a, 126 mg, 0.326 mmol) was dissolved in dichloromethane (5 mL), and a 1 M boron trichloride solution in dichloromethane (5 mL) was added under ice bath conditions. The reaction mixture was reacted under ice bath conditions for 1 hour. The reaction solution was quenched with methanol under ice bath conditions and concentrated under reduced pressure. The crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product 7-cyclobutoxy-1-(hydroxymethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-17-b, 30 mg, yield 37.2%). ESI[M+H) + =247.9

[0234] Step 3: Preparation of 7-cyclobutoxy-4-oxo-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-17)

[0235] 7-Cyclobutoxy-1-(hydroxymethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-17-b, 30 mg, 0.121 mmol) was dissolved in ethyl acetate (5 mL), and manganese dioxide (105 mg, 1.21 mmol) was added. The reaction was carried out overnight at 65 °C. After filtration, the mixture was concentrated under reduced pressure to give the target product 7-cyclobutoxy-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-17, 24 mg, yield 81.6%). ESI[M+H] + =246.1

[0236] Preparation of intermediate I-18: 4-oxo-7-(trifluoromethyl)-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-18)

[0237]

[0238] Step 1: Preparation of 4-(2-(benzyloxy)acetyl)-6-(trifluoromethyl)nicotinic acid (I-18-a)

[0239] Under nitrogen protection, 1.27 mL of n-butyllithium (3.15 mmol) was slowly added dropwise to a 10 mL solution of tetrahydrofuran (0.53 mL, 3.15 mmol) at -78 °C. The mixture was then heated to 0 °C and slowly cooled to -78 °C. A 2 mL solution of tetrahydrofuran containing 200 mg, 1.05 mmol of 6-(trifluoromethyl)nicotinic acid was slowly added dropwise to the above reaction mixture, and the mixture was stirred at this temperature for 1.5 hours. Then, 0.6 mL of 2-(benzyloxy)-N-methoxy-N-methylacetamide (3.15 mmol) was added dropwise. After the addition was complete, the mixture was heated to -30 °C and stirred overnight. After the reaction was complete, the reaction solution was quenched with 10% citric acid solution, extracted with ethyl acetate, washed with saturated brine of the organic phase, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. The crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 0–80%) to obtain the target product 4-(2-(benzyloxy)acetyl)-6-(trifluoromethyl)nicotinic acid (I-18-a, 400 mg, crude product). ESI[M+H] + =340.2

[0240] Step 2: Preparation of 1-(benzyloxy)methyl)-7-(trifluoromethyl)pyrido[3,4-d]pyridazine-4(3H)-one (I-18-b)

[0241] 4-(2-(benzyloxy)acetyl)-6-(trifluoromethyl)nicotinic acid (I-18-a, 400 mg, 1.18 mmol) was dissolved in ethanol (5 mL), and hydrazine hydrate (70 μL, 1.41 mmol) was added. The reaction was carried out at 70 °C for 0.5 h. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 0–30%) to obtain the target product 1-(benzyloxy)methyl)-7-(trifluoromethyl)pyrido[3,4-d]pyridazine-4(3H)-one (I-18-b, 140 mg, yield 35%). ESI[M+H] + =336.2

[0242] Step 3: Preparation of 1-(hydroxymethyl)-7-(trifluoromethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-18-c)

[0243] 1-(benzyloxy)methyl)-7-(trifluoromethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-18-b, 140 mg, 0.42 mmol) was dissolved in dichloromethane (6 mL), and boron trichloride (0.63 mL, 0.63 mmol) was added at 0 °C. The reaction was carried out at this temperature for 2 hours. After the reaction was completed, saturated sodium bicarbonate solution was added at 0 °C to adjust the pH to alkaline. After stirring for 1 hour, the solution was concentrated to obtain the crude product. The crude product was purified by Flash column chromatography (dichloromethane:methanol = 0–10%) to obtain the target product 1-(hydroxymethyl)-7-(trifluoromethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-18-c, 70 mg, yield 68%). ESI[M+H] + =246.2

[0244] Step 4: Preparation of 4-oxo-7-(trifluoromethyl)-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-18)

[0245] 1-(hydroxymethyl)-7-(trifluoromethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-18-c, 70 mg, 0.29 mmol) was dissolved in ethyl acetate (5 mL), and manganese dioxide (249 mg, 2.9 mmol) was added. The reaction was carried out at 70 °C for 16 hours. After the reaction was completed, the reaction solution was filtered while hot to obtain the target product 4-oxo-7-(trifluoromethyl)-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-18, 44 mg, crude product). ESI[M+H] + =244.2

[0246] Intermediate I-19: Preparation of (3-fluorozacricyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-19)

[0247]

[0248] Step 1: Preparation of tert-butyl 3-fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (I-19-a)

[0249] 1-(tert-Butoxycarbonyl)-3-fluorozazeline-3-carboxylic acid (100 mg, 0.912 mmol) was dissolved in dichloromethane (5 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (174 mg, 0.912 mmol) and N,N-diisopropylethylamine (239 μL, 2.74 mmol) were added. After stirring in an ice bath for 20 minutes, 2-(piperazine-1) 3-fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-19-a, 96 mg, yield 48.2%) was reacted at room temperature for 4 hours, concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to give the target product tert-butyl 3-fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (I-19-a, 96 mg, yield 48.2%). ESI [M-56+H] + =378.2

[0250] Step 2: Preparation of (3-fluorozacriane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-19)

[0251] 3-Fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-19-a, 96 mg, 0.222 mmol) was dissolved in ethyl acetate (3 mL), and 4M ethyl acetate hydrochloride solution (3 mL) was added. The reaction was carried out at room temperature for 3 hours. After the reaction solution was concentrated under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with triethylamine. The crude product was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 8:1) to obtain the target product (3-fluoroazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-19, 35 mg, yield 47.4%). ESI [M+H] + =334.2

[0252] Preparation of intermediate I-20: 2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinic acid nitrile hydrochloride (I-20)

[0253]

[0254] Step 1: Preparation of tert-butyl 4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-20-a)

[0255] 2-Chloro-5-(trifluoromethyl)nicotinonitrile (200 mg, 0.968 mmol) and piperazine-1-carboxylic acid tert-butyl ester (178.6 mg, 0.959 mmol) were dissolved in N-methylpyrrolidone (3 mL), and potassium carbonate (199 mg, 1.44 mmol) was added. The mixture was reacted at 80 °C for 3 hours. Water (10 mL) was added dropwise to the reaction solution, and a white solid precipitated. The mixture was filtered, the filter cake was washed with water, collected, and concentrated under reduced pressure to obtain the target product, 4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-20-a, 350 mg, yield 97.6%). ESI [M-100+H] + =257.4, ESI[M-56+H] + =301.5

[0256] Step 2: Preparation of 2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinic acid nitrile hydrochloride (I-20)

[0257] 4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-20-a, 350 mg, 0.983 mmol) was dissolved in ethyl acetate (3 mL), and 4M ethyl acetate hydrochloride solution (4 mL) was added. After reacting at room temperature for 4 hours, the solution was concentrated under reduced pressure to obtain the target product 2-(piperazine-1-yl)-5-(trifluoromethyl)nicotinic acid nitrile hydrochloride (I-20, 310 mg, crude product). ESI[M+H] + =257.2

[0258] Preparation of intermediate I-21: 3-(5-(trifluoromethyl)pyrimidin-2-yl)-3,8-diazacyclic [3.2.1]octane hydrochloride (I-21)

[0259]

[0260] Step 1: Preparation of tert-butyl 4-(5-(trifluoromethyl)pyrazin-2-yl)piperazine-1-carboxylic acid (I-21-a)

[0261] Piperazine-1-carboxylic acid tert-butyl ester (486 mg, 2.61 mmol) was dissolved in N-methylpyrrolidone (20 mL). 2-chloro-5-(trifluoromethyl)pyrazine (500 mg, 2.74 mmol) and potassium carbonate (757 mg, 5.22 mmol) were added under ice bath conditions. After reacting at 80 °C for 4 hours, water (50 mL) was added to the reaction solution under ice bath conditions. The mixture was filtered, the filter cake was washed with water, and the cake was collected and concentrated under reduced pressure to obtain the target product, 4-(5-(trifluoromethyl)pyrazin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-21-a, 880 mg, yield 96.8%). ESI [M-56+H] + =277.2

[0262] Step 2: Preparation of 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrazine hydrochloride (I-21)

[0263] 4-(5-(trifluoromethyl)pyrazin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-21-a, 880 mg, 2.61 mmol) was dissolved in 4M ethyl acetate hydrochloride (10 mL) and reacted at room temperature for 4 hours. The reaction solution was filtered, and the solid was washed with petroleum ether to give the target 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrazine hydrochloride (I-21, 638 mg, yield 89.6%). ESI[M+H] + =233.2 Intermediate I-22: Preparation of 1-(5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-22)

[0264]

[0265] Step 1: Preparation of tert-butyl 4-(5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-22-a)

[0266] 2-Chloro-5-(trifluoromethyl)pyridine (500 mg, 2.68 mmol) was dissolved in N-methylpyrrolidone (13 mL), and piperazine-1-carboxylic acid tert-butyl ester (2.82 mg, 10 mmol) and potassium carbonate (557 mg, 4.02 mmol) were added. The mixture was reacted at 80 °C for 3 hours. Water (150 mL) was added, and the mixture was stirred, filtered, and the solid was collected and dried under vacuum to give the target product 4-(5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-22-a, 520 mg, yield 58.46%).

[0267] Step 2: Preparation of 1-(5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-22)

[0268] 4-(5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-22-a, 520 mg, 1.57 mmol) was dissolved in 4M ethyl acetate (6 mL) and reacted at room temperature for 3 hours. The reaction solution was filtered, and the solid was washed with petroleum ether to give the target product 1-(5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-22, 400 mg, yield 95.22%). ESI[M+H] + =232.0 Intermediate I-23: Preparation of 1-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-23)

[0269]

[0270] Step 1: Preparation of tert-butyl 4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-23-a)

[0271] Piperazine-1-carboxylic acid tert-butyl ester (301 mg, 1.62 mmol) and 2-chloro-3-methoxy-5-(trifluoromethyl)pyridine (156 mg, 0.737 mmol) were dissolved in N-methylpyrrolidone (4 mL), and potassium carbonate (153 mg, 1.11 mmol) was added. The mixture was reacted in a sealed tube at 85 °C for 4 hours. The reaction solution was cooled and quenched with water, extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure and purified by Flash chromatography (10 g silica gel column, petroleum ether:ethyl acetate = 10:1) to obtain the target product 4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-23-a, 153 mg, yield 57.42%). ESI [M+H] + =362.6

[0272] Step 2: Preparation of 1-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-23)

[0273] 4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-23-a, 153 mg, 0.423 mmol) was added to a 4M ethyl acetate hydrochloride solution (3 mL). After reacting at room temperature for 3 hours, the reaction solution was diluted several times with ethyl acetate and concentrated under reduced pressure to obtain the target product 1-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-23, 114 mg, crude product). ESI[M+H] + =262.5

[0274] Preparation of intermediate I-24: 6-bromo-4-(1-bromomethyl)phthalazin-1(2H)-one (I-24)

[0275]

[0276] Step 1: Preparation of methyl 4-bromo-2-propionylbenzoate (I-24-a)

[0277] Methyl 4-bromo-2-iodobenzoate (2 g, 5.87 mmol) was dissolved in tetrahydrofuran (22 mL), purged with nitrogen, and cooled to -78 °C. Then, 2 M isopropyl magnesium chloride tetrahydrofuran solution (3.23 mL, 6.45 mmol) was added dropwise. The reaction was carried out at -78 °C for 15 minutes, followed by the addition of propionic anhydride (982 μL, 7.62 mmol). The reaction was allowed to proceed overnight at room temperature. The reaction was quenched with saturated ammonium chloride aqueous solution, extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by Flash column chromatography (petroleum ether:ethyl acetate = 7:1) to obtain the target product, methyl 4-bromo-2-propionylbenzoate (I-24-a, 750 mg, yield 47.16%). ESI [M+H] + =271.2,273.2

[0278] Step 2: Preparation of 6-bromo-4-ethylphthalazine-1(2H)-one (I-24-b)

[0279] Methyl 4-bromo-2-propionylbenzoate (I-24-a, 350 mg, 1.29 mmol) was dissolved in ethanol (8 mL), and hydrazine hydrate (235 μL, 3.87 mmol) was added. The reaction mixture was reacted at 85 °C for 4 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product 6-bromo-4-ethylphthalazine-1(2H)-one (I-24-b, 290 mg, yield 88.75%). ESI [M+H] + =253.2,255.2

[0280] Step 3: Preparation of 6-bromo-4-(1-bromomethyl)phthalazin-1(2H)-one (I-24)

[0281] 6-Bromo-4-ethylphthalazine-1(2H)-one (I-24-b, 270 mg, 1.067 mmol) was dissolved in acetonitrile (10 mL), and N-bromosuccinimide (380 mg, 2.14 mmol) and azobisisobutyronitrile (158 mg, 0.962 mmol) were added. The mixture was microwaved at 100 °C for 1 hour. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:2) to obtain the target product 6-bromo-4-(1-bromomethyl)phthalazine-1(2H)-one (I-24, 230 mg, yield 64.94%). ESI [M+H] + =331.2,333.2 Intermediate I-25: Preparation of 6-bromo-4-(2-bromoprop-2-yl)phthalazin-1(2H)-one (I-25)

[0282]

[0283] Step 1: Preparation of methyl 4-bromo-2-isobutyrylbenzoate (I-25-a)

[0284] Methyl 4-bromo-2-iodobenzoate (2 g, 5.87 mmol) was dissolved in tetrahydrofuran (22 mL). Under nitrogen protection, the solution was cooled to -78 °C, and 2 M isopropyl magnesium chloride tetrahydrofuran solution (3.23 mL, 6.45 mmol) was added dropwise. The reaction was carried out at -78 °C for 15 minutes, followed by the addition of isobutyric anhydride (1264 μL, 7.62 mmol). The reaction was allowed to proceed overnight at room temperature. The solution was quenched with saturated ammonium chloride aqueous solution, extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by Flash column chromatography (petroleum ether:ethyl acetate = 7:1) to obtain the target product, methyl 4-bromo-2-isobutyrylbenzoate (I-25-a, 1.3 g, yield 77.72%). ESI [M+H] + =285.2,287.2

[0285] Step 2: Preparation of 6-bromo-4-isopropylphthalazine-1(2H)-one (I-25-b)

[0286] Methyl 4-bromo-2-isobutyrylbenzoate (I-25-a, 800 mg, 2.81 mmol) was dissolved in ethanol (10 mL), and hydrazine hydrate (409 μL, 8.42 mmol) was added. The mixture was reacted at 85 °C for 3 hours, and then concentrated under reduced pressure. The crude product was slurried in ethyl acetate:acetonitrile = 1:1 to obtain the target product, 6-bromo-4-isopropylphthalazine-1(2H)-one (I-25-b, 670 mg, yield 89.6%). ESI[M+H] + =267.1,269.1

[0287] Step 3: Preparation of 6-bromo-4-(2-bromoprop-2-yl)phthalazin-1(2H)-one (I-25)

[0288] 6-Bromo-4-isopropylphthalazin-1(2H)-one (I-25-b, 270 mg, 1.02 mmol) was dissolved in carbon tetrachloride (10 mL), and N-bromosuccinimide (180 mg, 1.02 mmol) and azobisisobutyronitrile (166 mg, 1.02 mmol) were added. The reaction mixture was reacted overnight at 80 °C. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 6-bromo-4-(2-bromopropyl-2-yl)phthalazin-1(2H)-one (I-25, 164 mg, purity 50%, yield 23.5%). ESI [M+H] + =345.1,347.1

[0289] Preparation of intermediate I-26: 4-(bromomethyl)pyrido[3,4-d]pyridazin-1(2H)-one (I-26)

[0290]

[0291] Step 1: Preparation of 4-bromo-2-(carboxycarbonyl)benzoic acid (I-26-a)

[0292] 1-(5-bromo-2-methylphenyl)ethyl-1-one (1 g, 4.69 mmol), potassium permanganate (4.93 g, 32.85 mmol), and potassium carbonate (942 mg, 7.04 mmol) were dissolved in water (40 mL) and reacted at 50 °C for 3.5 h. Then, ethanol (40 mL) was added, and the reaction continued for another 0.5 h until a black solid completely precipitated. The reaction solution was cooled and filtered. The filtrate was concentrated under reduced pressure to remove most of the ethanol. The pH was adjusted to approximately 2 with 1 N hydrochloric acid solution in an ice bath. The solution was extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the target product, 4-bromo-2-(carboxycarbonyl)benzoic acid (I-26-a, 1.33 g, yield 103.91%). ESI[M+H] + =273.0,274.9

[0293] Step 2: Preparation of 7-bromo-4-oxo-3,4-dihydrophthalazine-1-carboxylic acid (I-26)

[0294] 4-Bromo-2-(carboxycarbonyl)benzoic acid (I-26-a, 1.23 g, 4.5 mmol) was dissolved in tetrahydrofuran (16 mL), and hydrazine hydrate (455 mg, 9.01 mmol) was added. The reaction mixture was reacted at 70 °C for 1 hour. The reaction solution was concentrated under reduced pressure to obtain the target product, 7-bromo-4-oxo-3,4-dihydrophthalazine-1-carboxylic acid (I-26, 1.36 g, yield 103.82%). ESI[M+H] + =269.0,271.0

[0295] Preparation of intermediate I-27: 2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-27)

[0296]

[0297] Step 1: Preparation of tert-butyl 4-(3-amino-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-27-a)

[0298] 4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-20-a, 550 mg, 1.54 mmol) was dissolved in ethanol (15 ml), and water (5 ml), potassium carbonate (640 mg, 4.63 mmol), and 30% hydrogen peroxide (3.3 ml) were added. After reacting at room temperature for 5 hours, the solvent was removed by concentration under reduced pressure, water (15 ml) was added, and the mixture was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure, and the crude product was purified by normal-phase column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 4-(3-amino-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-27-a, 256 mg, yield 44.3%). ESI[M+H] + =375.2.

[0299] Step 2: Preparation of 2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-27)

[0300] 4-(3-amino-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-27-a, 256 mg, 0.684 mmol) was dissolved in ethyl acetate (4 mL), and 4M ethyl acetate hydrochloride solution (4 mL) was added. After reacting at room temperature for 3 hours, the solution was concentrated under reduced pressure to give the target product 2-(piperazine-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-27, 194 mg, yield 91.5%). ESI[M+H] + =275.1

[0301] Preparation of intermediate I-28: 1-(3-ethoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-28)

[0302]

[0303] Step 1: Preparation of 2-chloro-3-ethoxy-5-trifluoromethylpyridine (I-28-a)

[0304] 2-Chloro-5-(trifluoromethyl)pyridin-3-ol (250 mg, 1.27 mmol) and iodoethane (203 μL, 2.53 mmol) were dissolved in N,N-dimethylformamide (15 mL), and cesium carbonate (619 mg, 1.89 mmol) was added. The mixture was reacted in a sealed tube at 90 °C for 1 hour. The reaction solution was cooled and quenched with water, extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure and purified by Flash chromatography (10 g silica gel column, petroleum ether:ethyl acetate = 6:1) to obtain the target product 2-chloro-3-ethoxy-5-trifluoromethylpyridine (I-28-a, 220 mg, yield 77.04%). ESI[M+H] +=225.9

[0305] Step 2: Preparation of tert-butyl 4-(3-ethoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-28-b)

[0306] Piperazine-1-carboxylic acid tert-butyl ester (218 mg, 1.17 mmol) and 2-chloro-3-ethoxy-5-trifluoromethylpyridine (I-28-a, 220 mg, 0.98 mmol) were dissolved in N-methylpyrrolidone (8 mL), and potassium carbonate (203 mg, 1.47 mmol) was added. The mixture was reacted overnight at 80 °C in a sealed tube. After cooling, the reaction solution was quenched with water, extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure and purified by Flash chromatography (10 g silica gel column, petroleum ether:ethyl acetate = 6:1) to obtain the target product 4-(3-ethoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-28-b, 120 mg, yield 32.69%). ESI [M+H] + =366.0

[0307] Step 3: Preparation of 1-(3-ethoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-28)

[0308] 4-(3-ethoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid tert-butyl ester (I-28-b, 115 mg, 0.31 mmol) was dissolved in 4M ethyl acetate hydrochloride solution (3 mL), reacted at room temperature for 2 hours, and then concentrated under reduced pressure to give the target product 1-(3-ethoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-28, 110 mg, yield 115.79%). ESI[M+H] + =311.0

[0309] Preparation of intermediate I-29: N-methyl-2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-29)

[0310]

[0311] Step 1: Preparation of tert-butyl 4-(3-(methoxycarbonyl)-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylic acid (I-29-a)

[0312] Methyl 2-chloro-5-(trifluoromethyl)nicotinate (500 mg, 2.087 mmol) and tert-butyl piperazine-1-carboxylate (408 mg, 2.194 mmol) were dissolved in N-methylpyrrolidone (15 mL), and potassium carbonate (432 mg, 3.13 mmol) was added. The mixture was reacted at 80 °C for 2 hours. The reaction solution was quenched with water and then extracted with ethyl acetate. The organic phases were combined, washed with brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to obtain the target product 4-(3-(methoxycarbonyl)-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylate tert-butyl (I-29-a, 764 mg, yield 93.81%).

[0313] Step 2: Preparation of 2-(4-(tert-Butoxycarbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinic acid (I-29-b)

[0314] 4-(3-(methoxycarbonyl)-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carboxylic acid tert-butyl (I-29-a, 740 mg, 1.9 mmol) and lithium hydroxide (146 mg, 3.476 mmol) were dissolved in methanol (20 mL) and water (4 mL) and reacted overnight at room temperature. After the reaction was completed, the pH was adjusted to 7 with acetic acid, and the mixture was extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the target product 2-(4-(tert-butyloxycarbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinic acid (I-29-b, 820 mg, yield 114.85%). ESI[M+H] + =376.3

[0315] Step 3: Preparation of tert-butyl 4-(3-(methylcarbamoyl)-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylate (I-29-c)

[0316] 2-(4-(tert-Butoxycarbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinic acid (I-29-b, 200 mg, 0.533 mmol) was dissolved in dichloromethane (10 mL), and O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (200 mg, 0.526 mmol) was added and stirred for 10 minutes. Then N,N-diisopropylethylamine (279 μL, 1.578 mmol) and methylamine hydrochloride (36 mg, 0.53 mmol) were added, and the mixture was reacted at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure and then purified by Flash chromatography (10 g silica gel column, petroleum ether: ethyl acetate = 1:1) to obtain the target product, tert-butyl 4-(3-(methylcarbamoyl)-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carboxylate (I-29-c, 220 mg, yield 106.38%). ESI [M+H] +=389.0

[0317] Step 4: Preparation of N-methyl-2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-29)

[0318] 4-(3-(methylcarbamoyl)-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carboxylic acid tert-butyl ester (I-29-c, 220 mg, 0.567 mmol) was dissolved in 4M ethyl acetate hydrochloride solution (3 mL), reacted at room temperature for 2 hours, and then concentrated under reduced pressure to obtain the target product N-methyl-2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-29, 193 mg, yield 105.46%). ESI[M+H] + =289.0

[0319] Preparation of intermediate I-30: 4,6-dibromo-2-(4-methoxybenzyl)phthalazine-1(2H)-one (I-30)

[0320]

[0321] Step 1: Preparation of 4,6-dibromophthalazine-1(2H)-one (I-30-a)

[0322] 6-Bromophthalazine-1(2H)-one (100 mg, 0.444 mmol) was dissolved in water (2 mL), and bromine (34 μL, 0.667 mmol) was added. The mixture was microwaved at 150 °C for 40 minutes. A white solid precipitated. The mixture was filtered, and the filter cake was collected and concentrated under reduced pressure to obtain the target product, 4,6-dibromophthalazine-1(2H)-one (I-30-a, 77 mg, purity 70%, yield 57.5%). ESI [M+H] + =303.1,305.1

[0323] Step 2: Preparation of 4,6-dibromo-2-(4-methoxybenzyl)phthalazine-1(2H)-one (I-30)

[0324] 4,6-Dibromophthalazine-1(2H)-one (I-30-a, 77 mg, 70% purity, 0.255 mmol) was dissolved in N,N-dimethylformamide (5 mL), and cesium carbonate (166 mg, 0.510 mmol) was added. After stirring at room temperature for 20 minutes, p-methoxybenzyl chloride (48 μL, 0.306 mmol) was added, and the reaction was carried out at room temperature for 4 hours. The reaction solution was quenched with water, and a white solid precipitated. The filter cake was collected, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product 4,6-dibromo-2-(4-methoxybenzyl)phthalazine-1(2H)-one (I-30, 28 mg, yield 37%). ESI[M+H] +=423.1,425.1

[0325] Preparation of intermediate I-31: 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-onitrile (I-31)

[0326]

[0327] Step 1: Preparation of methyl 2-acetyl-4-bromobenzoate (I-31-a)

[0328] Methyl 4-bromo-2-iodobenzoate (3 g, 8.82 mmol) was dissolved in 1,4-dioxane (50 mL), and tributyl(1-ethoxyethylene)tin (3.52 mL, 10.56 mmol) and 1,1-bis(diphenylphosphine)ferrocene palladium(II) dichloride (643 mg, 0.88 mmol) were added. The reaction mixture was reacted at 100 °C for 16 hours under nitrogen protection. The reaction mixture was then stirred for 1 hour with saturated potassium fluoride solution, filtered, and the filter cake was washed with ethyl acetate. The filtrate was extracted with ethyl acetate, and the organic phase was concentrated. 4 M hydrochloric acid solution was added and the mixture was stirred for 0.5 hours. The organic phase was extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and purified by Flash column chromatography (petroleum ether:ethyl acetate = 4:1) to obtain the target product, methyl 2-acetyl-4-bromobenzoate (I-31-a, 1.4 g, yield 61.7%). ESI [M+H] + =257.1,259.2

[0329] Step 2: Preparation of methyl 2-acetyl-4-cyanobenzoate (I-31-b)

[0330] Methyl 2-acetyl-4-bromobenzoate (I-31-a, 1.4 g, 5.45 mmol) was dissolved in N,N-dimethylformamide (10 mL), and zinc cyanide (382 mg, 3.27 mmol) and tetrakis(triphenylphosphine)palladium (315 mg, 0.273 mmol) were added. The reaction was carried out at 100 °C for 3 hours under nitrogen protection. After filtration and concentration under reduced pressure, the product was purified by Flash column chromatography (petroleum ether:ethyl acetate = 3:1) to obtain the target product, methyl 2-acetyl-4-cyanobenzoate (I-31-b, 450 mg, yield 38%). ESI [M+H] + =204.2

[0331] Step 3: Preparation of methyl 2-(2-bromoacetyl)-4-cyanobenzoate (I-31-c)

[0332] Methyl 2-acetyl-4-cyanobenzoate (I-31-b, 450 mg, 2.22 mmol) was dissolved in ethyl acetate (10 mL), and benzoyl peroxide (54 mg, 0.22 mmol) and N-bromosuccinimide (592 mg, 3.32 mmol) were added. The reaction was carried out at 80 °C for 3 hours under nitrogen protection. After the reaction was complete, the mixture was diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain the target product, methyl 2-(2-bromoacetyl)-4-cyanobenzoate (I-31-c, 650 mg, crude product). ESI[M+H] + =282.2,284.2

[0333] Step 4: Preparation of 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-onitrile (I-31)

[0334] Methyl 2-(2-bromoacetyl)-4-cyanobenzoate (I-31-c, 600 mg, 2.12 mmol) was dissolved in ethanol (8 mL), and hydrazine hydrate (160 μL, 2.55 mmol) was added. The reaction mixture was reacted at 80 °C for 3 hours. The reaction solution was concentrated under reduced pressure and then slurried with ethanol to obtain the target product, 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-onitrile (I-31, 120 mg, yield 21.6%). ESI[M+H] + =264.2,266.2

[0335] Intermediate I-32: Preparation of methyl 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-carboxylic acid ester (I-32)

[0336]

[0337] Step 1: Preparation of dimethyl 2-acetyl terephthalate (I-32-a)

[0338] Dimethyl 2-bromoterephthalate (3 g, 11.0 mmol), tributyl(1-ethoxyethylene)tin (5.9 mL, 16.5 mmol), and 1,1-bis(diphenylphosphine)ferrocene palladium(II) chloride (804 mg, 1.10 mmol) were dissolved in 1,4-dioxane (20 mL) and reacted overnight at 100 °C under nitrogen protection. After the reaction was completed, the solvent was removed by concentration under reduced pressure, quenched with saturated potassium fluoride aqueous solution, and then extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate, concentrated under reduced pressure, and then dissolved in tetrahydrofuran (15 mL). After stirring for 30 minutes with 6M hydrochloric acid (3 mL), the crude product was purified by Flash column chromatography (petroleum ether:ethyl acetate = 5:1) to obtain the target product, dimethyl 2-acetylterephthalate (I-32-a, 2.16 g, yield 83.4%). ESI [M-32+H]+ =205.1

[0339] Step 2: Preparation of methyl 4-methyl-1-oxo-1,2-dihydrophthalazine-6-carboxylic acid ester (I-32-b)

[0340] Dimethyl 2-acetyl terephthalate (I-32-a, 1 g, 4.24 mmol) was dissolved in ethanol (20 mL), and 80% hydrazine hydrate (321 μL) was added. The mixture was reacted at 85 °C for 2 hours, then concentrated under reduced pressure. The crude product was slurried with acetonitrile to obtain the target product, methyl 4-methyl-1-oxo-1,2-dihydrophthalazine-6-carboxylic acid (I-32-b, 850 mg, yield 92%). ESI[M+H] + =219.1

[0341] Step 3: Preparation of methyl 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-carboxylic acid (I-32)

[0342] Methyl 4-methyl-1-oxo-1,2-dihydrophthalazine-6-carboxylate (I-32-b, 100 mg, 0.459 mmol) was dissolved in carbon tetrachloride (3 mL), and N-bromosuccinimide (89 mg, 0.550 mmol) and azobisisobutyronitrile (75 mg, 0.459 mmol) were added. The reaction was carried out overnight at 80 °C. After concentration under reduced pressure, the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product, methyl 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-carboxylate (I-32, 100 mg, purity 50%, yield 36.8%). ESI [M+H] + =297.1,299.1

[0343] Preparation of intermediate I-33: 1-(5-(trifluoromethyl)pyrimidin-2-yl)piperidine-4-carboxylic acid (I-33)

[0344]

[0345] Step 1: Preparation of methyl 1-(5-(trifluoromethyl)pyrimidin-2-yl)piperidine-4-carboxylic acid (I-33-a)

[0346] Methyl piperidine-4-carboxylate (500 mg, 3.5 mmol) was dissolved in N-methylpyrrolidone (10 mL), and 2-chloro-5-(trifluoromethyl)pyrimidine (644 mg, 3.5 mmol) and potassium carbonate (720 mg, 5.2 mmol) were added. The mixture was reacted in an oil bath at 80 °C for 3 hours. After the reaction was complete, water (15 mL) was added, followed by extraction three times with ethyl acetate (8 mL). The mixture was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether:ethyl acetate = 2:1) to obtain the target product, methyl 1-(5-(trifluoromethyl)pyrimidin-2-yl)piperidine-4-carboxylate (I-33-a, 950 mg, yield 85.5%). ESI [M+H] + =290.2

[0347] Step 2: Preparation of 1-(5-(trifluoromethyl)pyrimidin-2-yl)piperidine-4-carboxylic acid (I-33)

[0348] Methyl 1-(5-(trifluoromethyl)pyrimidin-2-yl)piperidine-4-carboxylic acid (I-33-a, 940 mg, 3.24 mmol) was dissolved in tetrahydrofuran (10 mL) and water (3 mL), followed by the addition of sodium hydroxide (455 mg, 11.37 mmol). The reaction was carried out at room temperature for 3 hours. After the reaction was completed, the solution was concentrated under reduced pressure, and the product was dissolved in water (5 mL). The pH was adjusted to 2 by adding 1 M HCl aqueous solution under ice bath conditions, and the precipitated solid was the target product, 1-(5-(trifluoromethyl)pyrimidin-2-yl)piperidine-4-carboxylic acid (I-33, 1.2 g, crude product). ESI [M+H] + =276.2

[0349] Preparation of intermediate I-34: 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-3-nitrile (I-34)

[0350]

[0351] Step 1: Preparation of tert-butyl 3-cyano-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (I-34-a)

[0352] Dissolve 1-(tert-butoxycarbonyl)-3-cyanozazepane-3-carboxylic acid (100 mg, 0.442 mmol) in dichloromethane (5 mL), add 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (185 mg, 0.486 mmol) and N,N-diisopropylethylamine (232 μL, 1.33 mmol), stir for 20 minutes in an ice bath, then add 2-(piperazine- 1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azhecyclobutane-1-carboxylic acid tert-butyl ester (I-34-a, 88 mg, yield 45%) was reacted at room temperature for 4 hours, concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to give the target product 3-cyano-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-34-a, 88 mg, yield 45%). ESI [M-56+H] + =385.1

[0353] Step 2: Preparation of 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-3-nitrile (I-34)

[0354] 3-Cyano-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-34-a, 42 mg, 0.200 mmol) was dissolved in ethyl acetate (3 mL), and 4M ethyl acetate hydrochloride solution (3 mL) was added. The reaction was carried out at room temperature for 3 hours. After the reaction solution was concentrated under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with triethylamine. The crude product was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 8:1) to obtain the target product 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-3-onitrile (I-34, 19 mg, yield 27.6%). ESI [M+H] + =340.1

[0355] Preparation of intermediate I-35: (3-hydroxyazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-35)

[0356]

[0357] Step 1: Preparation of tert-butyl 3-hydroxy-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (I-35-a)

[0358] 1-(tert-Butoxycarbonyl)-3-hydroxyazacyclobutane-3-carboxylic acid (150 mg, 0.691 mmol) was dissolved in dichloromethane (5 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (289 mg, 0.759 mmol) and N,N-diisopropylethylamine (353 μL, 2.07 mmol) were added. After stirring in an ice bath for 20 minutes, 2-(piperazine-1) 3-hydroxy-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-35-a, 94 mg, yield 31.5%) was reacted at room temperature for 4 hours, concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to give the target product 3-hydroxy-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-35-a, 94 mg, yield 31.5%). ESI [M-56+H] + =376.1

[0359] Step 2: Preparation of (3-hydroxyazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-35)

[0360] 3-Hydroxy-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-35-a, 94 mg, 0.218 mmol) was dissolved in ethyl acetate (3 mL), and 4M ethyl acetate hydrochloride solution (3 mL) was added. The reaction was carried out at room temperature for 3 hours. After the reaction solution was concentrated under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with triethylamine. The crude product was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 8:1) to obtain the target product (3-hydroxyazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-35, 30 mg, yield 41.6%). ESI [M+H] + =332.1 Preparation of intermediate I-36: 2-chloro-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)acet-1-one (I-36)

[0361]

[0362] 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 300 mg, 1.29 mmol) and N,N-diisopropylethylamine (1 mL, 6.45 mmol) were dissolved in tetrahydrofuran (10 mL), and chloroacetyl chloride (124 μL, 1.55 mmol) was added at 0 °C. The reaction was carried out at room temperature for 3 hours. After the reaction was complete, the reaction solution was diluted with saturated ammonium chloride solution, extracted three times with ethyl acetate, and the mixed organic phase was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. The crude product was purified by Flash column chromatography (ethyl acetate: petroleum ether = 1:1) to obtain the target product 2-chloro-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl-1-one (I-36, 90 mg). ESI [M+H] + =309.2,311.2

[0363] Preparation of intermediate I-37: 2-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)acet-1-one (I-37)

[0364]

[0365] Step 1: Preparation of tert-butyl (2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)carbamate (I-37-a)

[0366] (tert-Butoxycarbonyl)glycine (500 mg, 2.85 mmol) and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 843 mg, 3.14 mmol) were dissolved in dichloromethane (15 mL), and N,N-diisopropylethylamine (1.5 mL, 8.55 mmol) and O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (1.08 g, 2.85 mmol) were added. The reaction was carried out at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 2:1) to obtain the target product (2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)carbamate tert-butyl ester (I-37-a, 1.194 g, yield 107.47%). ESI[M-56+H] + =334.2

[0367] Step 2: Preparation of 2-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)acet-1-one (I-37)

[0368] (2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)tert-butyl carbamate (I-37-a, 1.1 g, 2.83 mmol) was dissolved in ethyl acetate (5 mL), and 4M ethyl acetate hydrochloride solution (15 mL) was added. The reaction mixture was reacted at room temperature for 2 hours. After concentration under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with sodium bicarbonate solution. The crude product was concentrated under reduced pressure to obtain the target product 2-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl-1-one (I-37, 500 mg, yield 61.19%). ESI[M+H] + =290.3

[0369] Preparation of intermediate I-38: (S)-morpholin-2-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-38)

[0370]

[0371] Step 1: Preparation of (S)-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-38-a)

[0372] (S)-4-(tert-Butoxycarbonyl)morpholine-2-carboxylic acid (200 mg, 0.865 mmol) was dissolved in dichloromethane (5 mL), followed by the addition of 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (398 mg, 1.04 mmol) and N,N-diisopropylethylamine (453 μL, 2.60 mmol). After stirring for 20 minutes in an ice bath, 2-(piperazine-1- (S)-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-38-a, 195 mg, yield 50.6%) was reacted with 5-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-38-a, 195 mg, yield 50.6%) at room temperature for 4 hours. ESI [M-56+H] + =490.2

[0373] Step 2: Preparation of (S)-morpholin-2-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-38)

[0374] (S)-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-38-a, 195 mg, 0.438 mmol) was dissolved in ethyl acetate (3 mL), and 4M ethyl acetate hydrochloride solution (5 mL) was added. The reaction was carried out at room temperature for 3 hours. After the reaction solution was concentrated under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with triethylamine. The crude product was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 8:1) to obtain the target product (S)-morpholine-2-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-38, 150 mg, yield 98%). ESI[M+H] + =346.1

[0375] Preparation of intermediate I-39: (3-(hydroxymethyl)cyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-39)

[0376]

[0377] Step 1: Preparation of 3-(hydroxymethyl)cyclobutane-1-carboxylic acid (I-39-a)

[0378] Methyl 3-(hydroxymethyl)cyclobutane-1-carboxylic acid (100 mg, 0.694 mmol) was dissolved in tetrahydrofuran (3 mL), water (1 mL) and lithium hydroxide hydrate (87 mg, 2.08 mmol) were added. The mixture was reacted at room temperature for 40 minutes, and the solvent was removed by concentration under reduced pressure. The pH was adjusted to 2 with 1 M hydrochloric acid solution, and after concentration under reduced pressure, dichloromethane:methanol = 8:1 was added. The mixture was sonicated and filtered. The filtrate was concentrated under reduced pressure to obtain the target product 3-(hydroxymethyl)cyclobutane-1-carboxylic acid (I-39-a, 90 mg, yield 97.8%).

[0379] Step 2: Preparation of (3-(hydroxymethyl)cyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-39)

[0380] 3-(hydroxymethyl)cyclobutane-1-carboxylic acid (I-39-a, 90 mg, 0.682 mmol) was dissolved in dichloromethane (5 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (285 mg, 0.75 mmol) and N,N-diisopropylethylamine (477 μL, 2.73 mmol) were added. After stirring in an ice bath for 20 minutes, 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 184 mg, 0.682 mmol) was added. After reacting at room temperature for 4 hours, the mixture was concentrated under reduced pressure. The crude product was purified by Flash column chromatography (ethyl acetate) to obtain the target product (3-(hydroxymethyl)cyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-39, 130 mg, yield 55.3%). ESI[M+H] + =345.2

[0381] Preparation of intermediate I-40: ((1S,3S)-3-hydroxycyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-40)

[0382]

[0383] Step 1: Preparation of (1S,3S)-3-hydroxycyclobutane-1-carboxylic acid (I-40-a)

[0384] Methyl (1S,3S)-3-hydroxycyclobutane-1-carboxylate (100 mg, 0.768 mmol) was dissolved in tetrahydrofuran (2 mL) and water (1 mL), and lithium hydroxide monohydrate (48 mg, 1.15 mmol) was added. The mixture was stirred at room temperature for 1 hour. The reaction solution was adjusted to pH 5-6 by adding 1 M hydrochloric acid solution in an ice bath, and then concentrated under reduced pressure to obtain the target product (1S,3S)-3-hydroxycyclobutane-1-carboxylic acid (I-40-a, 100 mg, crude product). ESI[M+H] + =117.1

[0385] Step 2: Preparation of ((1S,3S)-3-hydroxycyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-40)

[0386] (1S,3S)-3-hydroxycyclobutane-1-carboxylic acid (I-40-a, 100 mg, 0.766 mmol) and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 206 mg, 0.766 mmol) were dissolved in dichloromethane (7 mL), N,N-diisopropylethylamine (400 μL, 2.298 mmol) was added, and finally N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (292 mg, 0.766 mmol) was added. The mixture was stirred at room temperature for 1.5 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (10 g silica gel column, dichloromethane:methanol = 10:1) to obtain the target product ((1S,3S)-3-hydroxycyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-40, 241 mg, yield 95.26%). ESI [M+H + =331.3

[0387] Preparation of intermediate I-41:(R)-morpholin-2-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-41)

[0388]

[0389] Step 1: Preparation of (R)-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-41-a)

[0390] (R)-4-(tert-Butoxycarbonyl)morpholine-2-carboxylic acid (500 mg, 2.16 mmol) was dissolved in N,N-dimethylformamide (8 mL), and O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronic acid hexafluorophosphate (820 mg, 2.16 mmol) and N,N-diisopropylethylamine (1.2 mL, 6.5 mmol) were added. The mixture was stirred for 10 minutes, and then 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine (I-6, 500 mg, 2.16 mmol) was added. The mixture was reacted overnight at room temperature. After the reaction was completed, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 2:1) to obtain the target product (R)-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-41-a, 480 mg, yield 49.9%) ESI[M+H). + =446.30

[0391] Step 2: Preparation of (R)-morpholin-2-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-41)

[0392] (R)-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)morpholine-4-carboxylic acid tert-butyl ester (I-41-a, 380 mg) was dissolved in ethyl acetate solution (4 mL), followed by the addition of ethyl hydrogen chloride solution (4 mL). The reaction was carried out at room temperature for 3 hours. After the reaction was completed, the reaction solution was concentrated under reduced pressure, dissolved in dichloromethane, and a suitable amount of triethylamine was added dropwise until the pH of the reaction solution reached 8. The solution was then purified by Flash column chromatography (dichloromethane:methanol = 3:1) to obtain the target product (R)-morpholine-2-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-41, 400 mg, yield 73.5%). ESI[M+H] + =346.30

[0393] Preparation of intermediate I-42: 3-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)prop-1-one (I-42)

[0394]

[0395] Step 1: Preparation of tert-butyl (3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)carbamate (I-42-a)

[0396] 3-((tert-Butoxycarbonyl)amino)propionic acid (2 g, 10.57 mmol) and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 2.83 g, 10.57 mmol) were dissolved in dichloromethane (50 mL), and N,N-diisopropylethylamine (1.5 mL, 8.55 mmol) and O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (4.01 g, 10.57 mmol) were added. The reaction mixture was reacted at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product tert-butyl 3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)carbamate (I-42-a, 3.41 g, yield 79.47%). ESI[M-56+H] + =348.2

[0397] Step 2: Preparation of 3-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)prop-1-one (I-42)

[0398] 3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)tert-butyl carbamate (I-42-a, 1.5 g, 3.72 mmol) was dissolved in ethyl acetate (10 mL), and 15 mL of 4M ethyl acetate hydrochloride solution was added. The reaction mixture was reacted at room temperature for 1 hour. After concentration under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with sodium bicarbonate solution. The crude product was concentrated under reduced pressure to obtain the target product 3-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl-1-one (I-42, 400 mg, yield 35.44%). ESI[M+H] + =304.1

[0399] Preparation of intermediate I-43: (2,2-dimethylazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone trifluoroacetate (I-43)

[0400]

[0401] Step 1: Preparation of tert-butyl 2,2-dimethyl-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (I-43-a)

[0402] 1-(tert-Butoxycarbonyl)-2,2-dimethylazacyclobutane-3-carboxylic acid (40 mg, 0.175 mmol) and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine (I-6, 45 mg, 0.192 mmol) were dissolved in N,N-dimethylformamide (3 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (80 mg, 0.21 mmol) and N,N-diisopropylethylamine (9 μL, 0.525 mmol) were added. The reaction was carried out at room temperature for 16 hours under nitrogen protection. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product, tert-butyl 2,2-dimethyl-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (I-43-a, 65 mg, yield 83.8%). ESI [M+H] + =444.2

[0403] Step 2: Preparation of (2,2-dimethylazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone trifluoroacetate (I-43)

[0404] 2,2-Dimethyl-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-43-a, 65 mg, 0.147 mmol) was dissolved in dichloromethane (5 mL), and trifluoroacetic acid (1 mL) was added. The reaction was carried out at room temperature for 1 hour. After the reaction was completed, the reaction solution was concentrated under reduced pressure to obtain the target product 4-(azacyclobutane-3-yl)-1-oxo-1,2-dihydrophthalazine-6-onitrile trifluoroacetate (I-43, 100 mg, crude product). ESI[M+H] + =344.2

[0405] Preparation of intermediate I-44: ((1R,3R)-3-hydroxycyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-44)

[0406]

[0407] Step 1: Preparation of (1R,3R)-3-hydroxycyclobutane-1-carboxylic acid (I-44-a)

[0408] Methyl (1R,3R)-3-hydroxycyclobutane-1-carboxylate (100 mg, 0.768 mmol) was dissolved in tetrahydrofuran (2 mL) and water (1 mL), and lithium hydroxide monohydrate (48 mg, 1.15 mmol) was added. The mixture was stirred at room temperature for 1 hour. The reaction solution was adjusted to pH 5-6 by adding 1 M hydrochloric acid solution under ice bath conditions, and then concentrated under reduced pressure to obtain the target product (1R,3R)-3-hydroxycyclobutane-1-carboxylic acid (I-44-a, 100 mg, crude product). ESI[M+H] + =117.1

[0409] Step 2: Preparation of ((1R,3R)-3-hydroxycyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-44)

[0410] (1R,3R)-3-hydroxycyclobutane-1-carboxylic acid (I-44-a, 100 mg, 0.766 mmol) and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 206 mg, 0.766 mmol) were dissolved in dichloromethane (7 mL), N,N-diisopropylethylamine (400 μL, 2.298 mmol) was added, and finally N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (292 mg, 0.766 mmol) was added. The mixture was stirred at room temperature for 1.5 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (10 g silica gel column, dichloromethane:methanol = 10:1) to obtain the target product ((1R,3R)-3-hydroxycyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-44, 241 mg, yield 95.26%). ESI [M+H + =331.3

[0411] Preparation of intermediate I-45: (4-hydroxypyrrolidone-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (I-45)

[0412]

[0413] Step 1: Preparation of 1-(tert-Butoxycarbonyl)-4-hydroxypyrrolidine-3-carboxylic acid (I-45-a)

[0414] 1-(tert-butyl)-3-ethyl-4-hydroxypyrrolidine-1,3-dicarboxylic acid ester (150 mg, 0.578 mmol) was dissolved in tetrahydrofuran (3 mL) and water (1 mL), and lithium hydroxide monohydrate (36 mg, 0.868 mmol) was added. The mixture was stirred at room temperature for 1.5 hours. The reaction solution was adjusted to pH 6-7 by adding 1M hydrochloric acid aqueous solution under ice bath conditions, and then concentrated under reduced pressure. Methanol was added to dissolve the solution, and the mixture was filtered. The filtrate was concentrated under reduced pressure to obtain the target product 1-(tert-butyloxycarbonyl)-4-hydroxypyrrolidine-3-carboxylic acid (I-45-a, 130 mg, yield 97.74%).

[0415] Step 2: Preparation of tert-butyl 3-hydroxy-4-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)pyrrolidine-1-carboxylate (I-45-b)

[0416] 1-(tert-Butoxycarbonyl)-4-hydroxypyrrolidine-3-carboxylic acid (I-45-a, 130 mg, 0.562 mmol) and 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 151 mg, 0.562 mmol) were dissolved in dichloroethane (6 mL), N,N-diisopropylethylamine (295 μL, 1.686 mmol) was added, and finally N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (214 mg, 0.562 mmol) was added. The mixture was stirred overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (10 g silica gel column, petroleum ether: ethyl acetate = 3:1) to obtain the target product, tert-butyl 3-hydroxy-4-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)pyrrolidine-1-carboxylate (I-45-b, 113 mg, yield 45.13%). ESI [M+H] + =446.3

[0417] Step 3: Preparation of (4-hydroxypyrrolidone-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (I-45)

[0418] 3-Hydroxy-4-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidine-1-carboxylic acid tert-butyl ester (I-45-b, 113 mg, 0.254 mmol) was dissolved in 4M ethyl acetate hydrochloride solution (3 mL) and stirred at room temperature for 2.5 hours. The reaction solution was repeatedly added to ethyl acetate and concentrated under reduced pressure to obtain the target product (4-hydroxypyrrolidine-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (I-45, 117 mg, crude product). ESI [M+H] + =346.2

[0419] Intermediate I-46: Preparation of aziridine-3-yl(morpholino)methyl ketone (I-46)

[0420]

[0421] Step 1: Preparation of benzyl 3-(morpholino-4-carbonyl)azacyclobutane-1-carboxylate (I-46-a)

[0422] 1-(benzyloxy)carbonyl)azacyclobutane-3-carboxylic acid (500 mg, 2.13 mmol) was dissolved in dichloromethane (10 mL), and thionyl chloride (230 μL, 3.18 mmol) was added under ice bath conditions. After stirring at room temperature for 40 minutes, morpholine (280 μL, 3.18 mmol) and triethylamine (590 μL, 4.25 mmol) were added, and the reaction was carried out at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product, benzyl 3-(morpholine-4-carbonyl)azacyclobutane-1-carboxylic acid (I-46-a, 480 mg, yield 72.4%). ESI [M+H] + =305.1

[0423] Step 2: Preparation of aziridine-3-yl(morpholino)methyl ketone (I-46)

[0424] Benzyl 3-(morpholino-4-carbonyl)azacyclobutane-1-carboxylate (I-46-a, 480 mg, 1.58 mmol) was dissolved in methanol (10 mL), and 10% palladium on carbon (168 mg, 1.58 mmol) was added. The reaction mixture was reacted overnight at room temperature under hydrogen protection. After filtration, the filtrate was concentrated under reduced pressure to obtain the target product, azacyclobutane-3-yl(morpholino) methyl ketone (I-46, 320 mg, crude product). ESI [M+H] + =171.1 Example 1: Preparation of (R)-6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidine-1-yl)methyl)phthalazin-1(2H)-one (1)

[0425]

[0426] Step 1: Preparation of (R)-6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)pyrrolidine-1-yl)methyl)phthalazine-1(2H)-one (1-a)

[0427] (R)-pyrrolidone-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-10, 50 mg, 0.151 mmol) and 6-bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 48.5 mg, 0.153 mmol) were dissolved in dichloromethane (2 mL) and reacted at room temperature for 3 hours. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography (dichloromethane:methanol = 10:1) to obtain the target product (R)-6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidone-1-yl)methyl)phthalazin-1(2H)-one (1-a, 11 mg, yield 12.8%). ESI [M+H] + =566.2, 568.2

[0428] Step 2: Preparation of (R)-6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidine-1-yl)methyl)phthalazin-1(2H)-one (1)

[0429] (R)-6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)pyrrolidine-1-yl)methyl)phthalazine-1(2H)-one (1-a, 11 mg, 0.019 mmol), 1-propynyl-tri-n-butyltin (9.6 mg, 0.029 mmol), and tetrakis(triphenylphosphine)palladium (2.24 mg, 0.002 mmol) were dissolved in toluene (2 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 30%-60% over 30min] to obtain the target product (R)-6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)pyrrolidine-1-yl)methyl)phthalazin-1(2H)-one (1, 1.29 mg, yield 12.6%). ESI [M+H] + =526.2 1H NMR (400MHz, DMSO-d6) δ12.56(s,1H),8.72(s,2H),8.22–8.10(m,2H),7.78(d,J=8.1Hz,1H),3.83(d,J=15.6Hz,4H),3.56(s,4H),2 .92(t,J=8.7Hz,1H),2.70(dd,J=15.0,8.1Hz,2H),2.61–2.55(m,1H),2.41(dd,J=17.4,9.6Hz,3H),2.14(s,3H),2.02–1.90(m,2H).

[0430] Example 2: Preparation of 6-(prop-1-yn-1-yl)-4-((((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (2)

[0431]

[0432] Step 1: Preparation of 6-bromo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (2-a)

[0433] 6-Bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 80 mg, 0.253 mmol) and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 91.9 mg, 0.279 mmol) were dissolved in dichloromethane (3 mL), and the reaction was stirred at room temperature for 3 hours. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated under reduced pressure and purified by thin-layer chromatography on silica gel plates (dichloromethane:methanol = 10:1) to give the target product 6-bromo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)phthalazin-1(2H)-one (2-a, 10 mg, yield 23.3%). ESI [M+H] + =566.1, 568.1

[0434] Step 2: Preparation of 6-(prop-1-yn-1-yl)-4-((((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (2)

[0435] 6-Bromo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (2-a, 10 mg, 0.017 mmol), 1-propynyl-tri-n-butyltin (8.7 mg, 0.026 mmol), and tetrakis(triphenylphosphine)palladium (2.1 mg, 0.002 mmol) were dissolved in toluene (2 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 30%-60% over 30min] to obtain the target product 6-(prop-1-yn-1-yl)-4-((((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (2.05 mg, yield 22.1%). ESI [M+H] + =526.2 1 H NMR(400MHz,DMSO-d6)δ12.56(s,1H),8.73(s,2H),8.30(s,1H),8.21–8.08(m ,1H),7.77(d,J=8.2Hz,1H),6.83(d,J=26.6Hz,2H),6.69–6.56(m,1H),4.09–3 .93(m,1H),3.84(d,J=24.6Hz,2H),2.29(dd,J=16.6,9.4Hz,2H),2.21–2.08( m,2H),1.99(s,2H),1.36(t,J=8.5Hz,5H),1.23(s,5H),0.84(d,J=7.1Hz,2H).

[0436] Example 3: Preparation of 6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (3)

[0437]

[0438] Step 1: Preparation of 6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (3-a)

[0439] 6-Bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 50 mg, 0.158 mmol) and aziridine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 54.8 mg, 0.174 mmol) were dissolved in dichloromethane (2 ml), and the reaction was stirred at room temperature for 3 hours. After the reaction was complete, the mixture was filtered, and the filtrate was concentrated under reduced pressure and purified by thin-layer chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)aziridine-1-yl)methyl)phthalazin-1(2H)-one (3-a, 28 mg, yield 32.1%). ESI[M+H] + =552.1, 554.1

[0440] Step 2: Preparation of 6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (3)

[0441] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (3-a, 28 mg, 0.051 mmol), 1-propynyl-tri-n-butyltin (25 mg, 0.076 mmol), and tetrakis(triphenylphosphine)palladium (5.8 mg, 0.005 mmol) were dissolved in toluene (2 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 5%-100% over 30min] to obtain the target product 6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (3, 3.21 mg, yield 22.1%). ESI [M+H] + =512.2 1 H NMR (400MHz, DMSO-d6) δ12.60(s,1H),8.72(s,2H),8.16(dd,J=27.1,18.9Hz,2H),7.78(d ,J=8.2Hz,1H),3.78(s,4H),3.51(dd,J=28.7,6.3Hz,7H),3.29–3.21(m,4H),2.14(s,3H).

[0442] Example 4: Preparation of 6-(prop-1-yn-1-yl)-4-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (4)

[0443]

[0444] Step 1: Preparation of 6-bromo-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (4-a)

[0445] ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-9, 50 mg, 0.158 mmol) and 6-bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 52.6 mg, 0.159 mmol) were dissolved in dichloromethane (2 ml) and reacted at room temperature for 3 hours. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)phthalazin-1(2H)-one (4-a, 19 mg, yield 21.2%). ESI [M+H] + =566.2, 568.2

[0446] Step 2: Preparation of 6-(prop-1-yn-1-yl)-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (4)

[0447] 6-Bromo-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (4-a, 19 mg, 0.034 mmol), 1-propynyl-tri-n-butyltin (16.6 mg, 0.050 mmol), and tetrakis(triphenylphosphine)palladium (3.9 mg, 0.003 mmol) were dissolved in toluene (2 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 20ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 30%-60% over 30min] to obtain the target product 6-(prop-1-yn-1-yl)-4-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (4, 0.77 mg, yield 4.37%). ESI [M+H] + =526.2 1 H NMR (600MHz, DMSO-d6) δ12.95(s,1H),8.74(s,2H),8.23(d,J=8.2Hz,1H),8.06(s,1H),7.86(d,J=8.2Hz,1H),3.89–3.77(m,4H ),3.57(s,2H),3.48(d,J=4.1Hz,2H),3.42–3.36(m,3H),3.26(dd,J=10.8,2.2Hz,2H),2.61(s,2H),2.38(s,2H),2.14(s,3H).

[0448] Example 5: Preparation of 6-ethynyl-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (5)

[0449]

[0450] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (3-a, 10 mg, 0.018 mmol), tributyl(ethynyl)stanane (17 μL, 0.054 mmol) and tetra(triphenylphosphine)palladium (2.1 mg, 0.002 mmol) were dissolved in toluene (2 mL) and reacted at 110 °C under microwave conditions for 2 hours. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 20ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 5%-45% over 30min] to obtain the target product 6-ethynyl-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (5, 0.60 mg, yield 6.66%). ESI [M+H] + =498.5 1 H NMR (600MHz, DMSO-d6) δ12.63(s,1H),8.72(s,2H),8.28(s,1H),8.20(s,1H),7.87(d,J=8.2Hz,1H),3.80 (s,3H),3.55(dd,J=12.8,7.2Hz,3H),3.50–3.44(m,3H),3.25(d,J=7.2Hz,5H),2.61(s,1H),2.38(s,1H).

[0451] Example 6: Preparation of 6-ethynyl-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (6)

[0452]

[0453] 6-Bromo-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (4-a, 18 mg, 0.032 mmol), tributyl(ethynyl)stanane (30 μl, 0.096 mmol) and tetrakis(triphenylphosphine)palladium (3.7 mg, 0.003 mmol) were dissolved in toluene (2 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 20ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 5%-45% over 30min] to obtain the target product 6-ethynyl-4-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (6, 0.63 mg, yield 3.87%). ESI [M+H] + =512.4 1 H NMR (600MHz, DMSO-d6) δ12.59(s,1H),8.72(s,2H),8.42(s,1H),8.24(s,1H),8.21(d,J=8.1Hz,1H),3.89(s,2H),3.79(s,3H), 3.54–3.50(m,2H),3.47–3.44(m,2H),3.15–3.10(m,2H),2.97–2.92(m,2H),2.89(s,1H),2.03–1.97(m,2H),1.86–1.81(m,2H).

[0454] Example 7: Preparation of 6-cyclobutoxy-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)o-phthalazin-1(2H)-one (7)

[0455]

[0456] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 18 mg, 0.0584 mmol) was dissolved in dichloromethane (2 ml), and 4-(bromomethyl)-6-cyclobutoxy-1(2H)-one (I-2, 12 mg, 0.0389 mmol) was added. The mixture was reacted at room temperature for 1 hour. The reaction solution was purified by vacuum distillation using a silica gel plate (dichloromethane:methanol = 10:1), followed by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 30min] to obtain the target product 6-cyclobutoxy-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)o-phthalazin-1(2H)-one (7, 2.98 mg, yield 8.9%). ESI [M+H] + =544.0 1 H NMR (600MHz, DMSO-d6) δ12.76 (s, 1H), 8.74 (s, 2H), 8.20 (d, J = 8.2Hz, 1H), 7. 41(d,J=6.0Hz,1H),7.15(s,1H),4.97–4.91(m,1H),4.83–4.76(m,1H),4.40 (dd,J=89.5,30.2Hz,4H),3.82(t,J=28.9Hz,4H),3.63(d,J=21.5Hz,2H),3. 41(d,J=4.6Hz,2H),2.61–2.52(m,2H),2.14–2.05(m,2H),1.93–1.62(m,4H).

[0457] Example 8: Preparation of 6-cyclobutoxy-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)ophthalazine-1(2H)-one (8)

[0458]

[0459] Dissolve ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-7, 34.6 mg, 0.105 mmol) in dichloromethane (2 ml), then add 4-(bromomethyl)-6-cyclobutoxy-1-(2H)

[0460] - Ketone (I-2, 18 mg, 0.0584 mmol), reacted at room temperature for 1 hour. The reaction solution was purified by vacuum distillation using a silica gel plate (dichloromethane:methanol = 10:1), followed by high performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50 min] to obtain the target product 6-cyclobutoxy-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)o-phthalazine-1(2H)-one (8, 1.36 mg, yield 4.18%). (ESI)[M+H] + =558.2 1 H NMR(600MHz,DMSO-d6)δ12.84(s,1H),9.42(d,J=5.6Hz,2H),8.74(s,2H),8 .22(d,J=8.8Hz,1H),7.43(d,J=8.8Hz,1H),7.21(s,1H),4.99–4.93(m,1H), 4.52–4.44(m,2H),3.85(t,J=9.0Hz,4H),3.60(d,J=14.8Hz,2H),3.53–3.4 3(m,4H),2.15–1.95(m,4H),1.85(t,J=14.2Hz,2H),1.70(d,J=18.9Hz,2H).

[0461] Example 9: Preparation of 6-cyclobutoxy-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)ophthalazine-1(2H)-one (9)

[0462]

[0463] ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-9, 34.6 mg, 0.105 mmol) was dissolved in dichloromethane (2 ml), and 4-(bromomethyl)-6-cyclobutoxy-1-(2H)-one (I-2, 18 mg, 0.0584 mmol) was added. After reacting at room temperature for 1 hour, the mixture was purified by thin-layer chromatography (dichloromethane:methanol = 10:1) and then subjected to high-performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] [50 min] The target product 6-cyclobutoxy-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)o-phthalazine-1(2H)-one (9, 1.37 mg, yield 4.2%) was prepared and purified. (ESI)[M+H] + =558.2 1 H NMR (600MHz, DMSO-d6) δ12.81(s,1H),9.33(s,2H),8.74(s,2H),8.22(d,J=8.8Hz,1H),7.4 3(d,J=6.7Hz,1H),7.22(s,1H),5.01–4.93(m,1H),4.46(s,2H),3.93–3.73(m,4H),3.65–3 .42(m,4H),2.10(dt,J=19.0,9.7Hz,2H),2.03–1.90(m,2H),1.84(dd,J=18.1,7.7Hz,1H), 1.70(dd,J=22.8,11.1Hz,2H), 1.45(dd,J=14.4,7.3Hz,1H), 1.30(dd,J=23.0,14.1Hz,2H).

[0464] Example 10: Preparation of 7-(prop-1-yn-1-yl)-1-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (10)

[0465]

[0466] Step 1: 7-Bromo-1-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)

[0467] Preparation of amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (10-a)

[0468] ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-9, 36 mg, 0.109 mmol) was dissolved in dichloromethane (2 ml), and 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4, 19.2 mg, 0.0606 mmol) was added. The reaction was carried out at room temperature for 30 minutes. After the reaction was concentrated under reduced pressure, the crude product was purified by normal phase column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-1-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (10-a, 5 mg, yield 14.6%).

[0469] (ESI)[M+H] + =567.2, 569.2

[0470] Step 2: Preparation of 6-cyclobutoxy-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)ophthalazine-1(2H)-one (10)

[0471] 7-Bromo-1-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (10-a, 5 mg, 8.81 μmol) was dissolved in toluene (2 ml), and 1-propynyl-tri-n-butyltin (4.4 μl, 13.2 μmol) and tetrakis(triphenylphosphine)palladium (1 mg, 0.88 μmol) were added. The mixture was reacted overnight at 100 °C under nitrogen protection. After filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50min] to obtain the target product 7-(prop-1-yn-1-yl)-1-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (10, 0.7 mg, yield 15%). ESI [M+H] + =527.2 1H NMR(600MHz,DMSO-d6)δ13.30(s,1H),9.39(s,1H),8.74(s,2H),8.02(s,1 H),4.05–4.00(m,5H),3.87–3.76(m,8H),2.48–2.37(m,4H),2.18(s,3H).

[0472] Example 11: Preparation of 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11)

[0473]

[0474] Step 1: Preparation of 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a)

[0475] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 53 mg, 0.170 mmol) was dissolved in dichloromethane (2 ml), and 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4, 30 mg, 0.0947 mmol) was added. The reaction was carried out at room temperature for 30 minutes. After concentration under reduced pressure, the crude product was purified by normal-phase column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 26 mg, yield 49.7%). ESI[M+H] + =553.2, 555.2.

[0476] Step 2: Preparation of 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11)

[0477] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 26 mg, 0.0471 mmol) was dissolved in toluene (2 ml), and 1-propynyl-tri-n-butyltin (23 μl, 0.0706 mmol) and tetrakis(triphenylphosphine)palladium (6 mg, 0.00471 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration, the mixture was concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] [50 min] The target product 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11, 2.38 mg, yield 9.9%) was prepared and purified to obtain [M+H]. + =513.2 1 HNMR(600MHz,DMSO-d6)δ13.23(s,1H),9.37(s,1H),8.74(s,2H),7.98(s,1H),3.89–3.81( m,4H),3.67–3.56(m,3H),3.42–3.38(m,4H),2.51(s,2H),2.50–2.49(m,2H),2.18(s,3H).

[0478] Example 12: Preparation of 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-onitrile (12)

[0479]

[0480] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)o-phthalazin-1(2H)-one (3-a, 17 mg, 0.0309 mmol) was dissolved in N,N-dimethylformamide (2 ml), and zinc cyanide (5.8 mg, 0.0494 mmol) and tetrakis(triphenylphosphine)palladium (4.3 mg, 0.00370 mmol) were added. The mixture was microwaved at 110 °C for 1 hour under nitrogen protection. After filtration, the filtrate was concentrated under reduced pressure, and the crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] [30 min] The target product 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-onitrile (12, 2.13 mg, yield 14.2%) was prepared and purified. (ESI)[M+H] + =499.1

[0481] Example 13: Preparation of 1-oxo-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)-1,2-dihydro-o-phthalazine-6-onitrile (13)

[0482]

[0483] 6-Bromo-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)o-phthalazin-1(2H)-one (4-a, 17 mg, 0.0301 mmol) was dissolved in N,N-dimethylformamide (2 ml), and zinc cyanide (5.7 mg, 0.081 mmol) and tetrakis(triphenylphosphine)palladium (4.2 mg, 0.00361 mmol) were added. The mixture was microwaved at 110 °C for 1 hour under nitrogen protection. After filtration, the filtrate was concentrated under reduced pressure, and the crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] [30 min] The target product 1-oxo-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)-1,2-dihydro-o-phthalazine-6-onitrile (13, 2.60 mg, yield 16.9%) was prepared and purified. (ESI)[M+H] + =513.4

[0484] Example 14: Preparation of 8-fluoro-6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (14)

[0485]

[0486] Step 1: Preparation of 6-bromo-8-fluoro-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (14-a)

[0487] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 14 mg, 0.045 mmol) and 6-bromo-4-bromomethyl-8-fluorophthalazin-1(2H)-one (I-5, 10 mg, 0.029 mmol) were dissolved in dichloromethane (2 mL) and reacted overnight at room temperature. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-8-fluoro-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (14-a, 9.6 mg, yield 56.5%). ESI [M+H] + =570.2, 572.2

[0488] Step 2: Preparation of 8-fluoro-6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (14)

[0489] 6-Bromo-8-fluoro-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (14-a, 9.6 mg, 0.0169 mmol), 1-propynyl-tri-n-butyltin (10 mg, 0.031 mmol) and tetra(triphenylphosphine)palladium (2 mg, 0.002 mmol) were dissolved in toluene (2 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%TFA), B:ACN, B%: 5%-50% over 50min] to obtain the target product 8-fluoro-6-(prop-1-yn-1-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (14, 0.61 mg, yield 6.84%). ESI [M+H] + =530.2

[0490] Example 15: Preparation of 3-(prop-1-yn-1-yl)-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (15)

[0491]

[0492] Step 1: Preparation of 3-bromo-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (15-a)

[0493] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 44 mg, 0.127 mmol) was dissolved in dichloromethane (3 mL), and 3-bromo-5-(bromomethyl)pyrido[2,3-d]pyridazin-8(7H)-one (I-3, 40 mg, 0.14 mmol) was added. The reaction was carried out at room temperature for 30 minutes. After concentration under reduced pressure, the crude product was purified by normal-phase column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 3-bromo-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (15-a, 14 mg, yield 20%). (ESI)[M+H] + =553.2, 555.2.

[0494] Step 2: Preparation of 3-(prop-1-yn-1-yl)-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (15)

[0495] 3-Bromo-5-(((1s,3s)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazine-8(7H)-one (15-a, 14 mg, 0.025 mmol) was dissolved in toluene (2 ml), and 1-propynyl-tri-n-butyltin (12.5 μl, 0.038 mmol) and tetrakis(triphenylphosphine)palladium (3 mg, 0.0025 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration, the mixture was concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% TFA), B: ACN, B%: 10%-100% over] [50 min] The target product 3-(prop-1-yn-1-yl)-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (15, 0.70 mg, yield 15%) was prepared and purified. ESI[M+H] + =513.4

[0496] Example 16: 3-(prop-1-yn-1-yl)-5-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (16)

[0497]

[0498] Step 1: Preparation of 3-bromo-5-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazine-8(7H)-one (16-a)

[0499] ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-9, 56 mg, 0.171 mmol) was dissolved in dichloromethane (2 ml), and 3-bromo-5-(bromomethyl)pyrido[2,3-d]pyridazin-8(7H)-one (I-3, 30 mg, 0.095 mmol) was added. The reaction was carried out at room temperature for 1 hour. After the reaction was concentrated under reduced pressure, the crude product was purified by normal phase column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 3-bromo-5-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (16-a, 10 mg, yield 18.5%). ESI[M+H] + =569.3

[0500] Step 2: Preparation of 3-(prop-1-yn-1-yl)-5-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (16)

[0501] 3-Bromo-5-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazine-8(7H)-one (16-a, 10 mg, 0.018 mmol) was dissolved in toluene (2 ml), and 1-propynyl-tri-n-butyltin (8.7 μl, 0.026 mmol) and tetrakis(triphenylphosphine)palladium (2 mg, 0.0018 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration, the mixture was concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% TFA), B: ACN, B%: 10%-100% over] [50 min] The target product 3-(prop-1-yn-1-yl)-5-(((1S,3S-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (16, 1.70 mg, yield 18.27%) was prepared and purified. ESI[M+H] + =527.4 Example 17: Preparation of 8-fluoro-6-(prop-1-yn-1-yl)-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (17)

[0502]

[0503] Step 1: Preparation of 6-bromo-8-fluoro-4-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (17-a)

[0504] ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-9, 25 mg, 0.077 mmol) and 6-bromo-4-bromomethyl-8-fluorophthalazin-1(2H)-one (I-5, 51 mg, 0.153 mmol) were dissolved in dichloromethane (2 ml) and reacted overnight at room temperature. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography on silica gel plates (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-8-fluoro-4-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)phthalazin-1(2H)-one (17-a, 8 mg, yield 8.9%). ESI [M+H] + =586.2, 584.2

[0505] Step 2: Preparation of 8-fluoro-6-(prop-1-yn-1-yl)-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (17)

[0506] 6-Bromo-8-fluoro-4-((((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (17-a, 8 mg, 0.014 mmol), 1-propynyl-tri-n-butyltin (9 μl, 0.025 mmol), and tetrakis(triphenylphosphine)palladium (2 mg, 0.002 mmol) were dissolved in toluene (3 ml) and reacted overnight at 100 °C. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by preparative liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1% TFA), B:ACN, B%: 5%-50% over 50min] to obtain the target product 8-fluoro-6-(prop-1-yn-1-yl)-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (17, 0.58 mg, yield 7.79%). ESI [M+H] + =544.2

[0507] Example 18: Preparation of 1-oxo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)-1,2-dihydrophthalazine-6-onitrile (18)

[0508]

[0509] Step 1: Preparation of 6-bromo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (18-a)

[0510] 6-Bromo-4-(bromomethyl)phthalazin-1(2H)-one (I-1, 100 mg, 50% purity, 0.159 mmol) was dissolved in dichloromethane (8 mL), and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 105 mg, 0.317 mmol) was added. The reaction was carried out at room temperature for 2 hours. After the reaction was completed, the crude product was concentrated under reduced pressure and purified by Flash (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)phthalazin-1(2H)-one (18-a, 15 mg, yield 16.8%). ESI[M+H] + =568.3,566.3

[0511] Step 2: Preparation of 1-oxo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)-1,2-dihydrophthalazine-6-onitrile (18)

[0512] 6-Bromo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (18-a, 15 mg, 0.026 mmol) was dissolved in N,N-dimethylformamide (3.5 mL), and zinc cyanide (5 mg, 0.042 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.0032 mmol) were added. The mixture was then microwaved at 110 °C for 1 hour under nitrogen protection. The filtrate was filtered, and the crude product was concentrated under reduced pressure and then purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 30min] to obtain the target product 1-oxo-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)-1,2-dihydrophthalazine-6-onitrile (18, 4.75 mg, yield 35.05%). ESI [M+H] + =513.30 1 H NMR (600MHz, DMSO-d6) δ13.25(s,1H),8.74(s,2H),8.65(s,1H),8.42(d,J=8.2Hz,1H),8.31(d,J=8.2 Hz,1H),4.53(s,2H),3.85(s,4H),3.60(s,2H),3.47(dd,J=17.6,10.4Hz,5H),2.53(d,J=17.7Hz,4H).

[0513] Example 19: Preparation of 7-fluoro-6-(propyl-1-ynyl)-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)diazanaphth-1(2H)-one (19)

[0514]

[0515] Step 1: Preparation of (19-a) from 6-bromo-7-fluoro-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)diazanaphth-1(2H)-one

[0516] (1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-9, 13 mg, 0.04 mmol) was dissolved in dichloromethane (2 mL), and 6-bromo-4-(bromomethyl)-7-fluorophthalazin-1(2H)-one (I-11, 25 mg, 0.074 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the crude product was purified by normal-phase column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-7-fluoro-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)diazanaphthalene-1(2H)-one (19-a, 8 mg, yield 18.4%). ESI[M+H] + =584.3,586.2

[0517] Step 2: Preparation of 7-fluoro-6-(propyl-1-ynyl)-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)diazanaphth-1(2H)-one (19)

[0518] 6-Bromo-7-fluoro-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)diazanaphth-1(2H)-one (19-a, 8 mg, 0.014 mmol) was dissolved in toluene (2 mL), and 1-propynyl-tri-n-butyltin (7 μL, 0.02 mmol) and tetrakis(triphenylphosphine)palladium (1.6 mg, 0.0013 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration, the mixture was concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] [50 min] The target product 7-fluoro-6-(propyl-1-ynyl)-4-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)diazanaphth-1(2H)-one (19, 0.58 mg, yield 7.8%) was prepared and purified. ESI [M+H] + =544.3 1 HNMR(600MHz,DMSO-d6)δ8.74(s,1H),7.20(s,2H),6.65(s,2H),3.82(dd,J=9.4,3.2Hz,2H), 3.56(s,1H),2.02–1.96(m,8H),1.47–1.43(m,2H),1.32–1.27(m,4H),0.85(t,J=6.8Hz,3H).

[0519] Example 20: Preparation of 7-fluoro-6-(prop-1-yn-1-yl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (20)

[0520]

[0521] Step 1: Preparation of (20-a) from 6-bromo-7-fluoro-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one

[0522] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 28 mg, 0.088 mmol) was dissolved in dichloromethane (2 mL), and 6-bromo-4-(bromomethyl)-7-fluorophthalazin-1(2H)-one (I-11, 30 mg, 0.09 mmol) was added. The reaction was carried out overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the crude product was purified by normal-phase column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-7-fluoro-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (20-a, 10 mg, yield 19.5%). ESI[M+H] + =570.2,572.2

[0523] Step 2: Preparation of 7-fluoro-6-(prop-1-yn-1-yl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (20)

[0524] 6-Bromo-7-fluoro-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (20-a, 10 mg, 0.018 mmol) was dissolved in toluene (2 mL), and 1-propynyl-tri-n-butyltin (9 μL, 0.026 mmol) and tetrakis(triphenylphosphine)palladium (2 mg, 0.0017 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50min] to obtain the target product 7-fluoro-6-(prop-1-yn-1-yl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (20, 1.09 mg, yield 11.72%). ESI [M+H] + =530.3 1 H NMR (600MHz, DMSO-d6) δ10.59(s,1H),8.74(s,2H),8.19(d,J=5.8Hz,1H),8.00(d,J=8. 8Hz,1H),4.81(s,2H),4.28(s,4H),3.85(s,4H),3.61(s,3H),3.39(s,2H),2.20(s,3H).

[0525] Example 21: Preparation of 3-cyclobutoxy-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (21)

[0526]

[0527] Step 1: Preparation of 3-bromo-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (21-a)

[0528] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 41.7 mg, 0.132 mmol) and 3-bromo-5-bromomethylpyridano[2,3-d]pyridazin-8(7H)-one (I-3, 28 mg, 0.089 mmol) were dissolved in dichloromethane (3 mL) and reacted at room temperature for 3 hours. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography on silica gel plates (dichloromethane:methanol = 10:1) to obtain the target product 3-bromo-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyridano[2,3-d]pyridazin-8(7H)-one (21-a, 19 mg, yield 39.02%). ESI[M+H] + =553.2,555.2

[0529] Step 2: Preparation of 3-cyclobutoxy-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazine-8(7H)-one (21)

[0530] 3-Bromo-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (21-a, 19 mg, 0.035 mmol), cyclobutanol (8 μL, 0.104 mmol), palladium acetate (0.3 mg, 0.001 mmol), cesium carbonate (22.4 mg, 0.069 mmol), and 5-(di(adamantane-1-yl)phosphinyl)-1',3',5'-triphenyl-1'H-1,4'-bipyrazole (1.8 mg, 0.002 mmol) were dissolved in toluene (3 mL) and reacted overnight at 110 °C under nitrogen. After the reaction was complete, the reaction solution was filtered, concentrated under reduced pressure, and purified by preparative liquid chromatography [Pack Column 20ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 5%-45% over 30min] to obtain the target product 3-cyclobutoxy-5-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[2,3-d]pyridazin-8(7H)-one (21, 0.91 mg, yield 4.86%). ESI [M+H] + =545.2

[0531] Example 22: Preparation of 6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (22)

[0532]

[0533] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 200 mg, 0.632 mmol), 6-bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 199.4 mg, 0.632 mmol), and triethylamine (220 μL, 1.58 mmol) were dissolved in dichloromethane (3 mL) and reacted at room temperature for 3 hours. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography on silica gel plates (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (22, 100 mg, yield 28.6%). ESI [M+H] + =552.5,554.5 1 H NMR (600MHz, DMSO-d6) δ12.68(s,1H),8.72(s,1H),8.36(s,1H),8.30(s,1H),8.14(d,J=8.5Hz,1H),8.00(d,J=8.5Hz,1H),3.81 (s,1H),3.79(s,3H),3.60–3.51(m,3H),3.48(t,J=7.3Hz,2H),3.44–3.39(m,2H),3.31(d,J=4.7Hz,2H),3.25(t,J=7.1Hz,2H).

[0534] Example 23: Preparation of 7-cyclobutoxy-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (23)

[0535]

[0536] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 30 mg, 0.0543 mmol) was dissolved in toluene (2 mL), and cesium carbonate (35.4 mg, 0.109 mmol), cyclobutanol (13 μL, 0.163 mmol), palladium acetate (0.53 mg, 2.17 μmol), and 5-(di(adamantane-1-yl)phosphino)-1',3',5'-triphenyl-1'H-1,4'-bipyrazole (2.88 mg, 4.35 μmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack] Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 10%-100% over 50min] Preparation and purification yielded the target product 7-cyclobutoxy-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (23, 0.90 mg, yield 3.04%). ESI[M+H + =545.2 1 H NMR (600MHz, DMSO-d6) δ12.55(s,1H),9.06(s,1H),8.71(s,1H),8.44(s,1H),7.24(s,1H),5.27(dd,J= 13.7,5.9Hz,1H),3.83–3.76(m,2H),3.73(t,J=9.2Hz,1H),3.53(dd,J=13.8,8.6Hz,2H),3.51–3.45(m ,3H),3.35(s,2H),3.26(dd,J=13.9,6.8Hz,1H),2.17–2.07(m,2H),1.85–1.79(m,1H),1.68(dd,J=17. 7,10.5Hz,1H),1.56–1.50(m,1H),1.31–1.21(m,2H),1.05–1.00(m,1H),0.84(dd,J=13.7,6.3Hz,2H).

[0537] Example 24: Preparation of 4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-1(2H)-one (24)

[0538]

[0539] 4-(bromomethyl)pyrido[3,4-d]pyridazin-1(2H)-one (I-12, 200 mg, 55% purity, 0.66 mmol) was dissolved in dichloromethane (4 mL) and methanol (1 mL), and then aziridine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 210 mg, 0.66 mmol) was added. The mixture was reacted overnight at room temperature. After the reaction, the product was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50min] to obtain the target product 4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-1(2H)-one (24, 35 mg, yield 8.89%). ESI [M+H] + =474.80 1 H NMR (600MHz, DMSO-d6) δ12.85(s,1H),9.49(s,1H),8.96(d,J=5.2Hz,1H),8.73(d,J=15.1Hz,2H),8.06(d,J= 5.2Hz,1H),3.88(s,2H),3.83–3.75(m,4H),3.56–3.47(m,5H),3.36(d,J=5.6Hz,2H),3.29(d,J=6.8Hz,2H).

[0540] Example 25: Preparation of 7-(prop-1-yn-1-yl)-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (25)

[0541]

[0542] Step 1: Preparation of 7-bromo-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (25-a)

[0543] ((1R,R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-7, 50 mg, 0.158 mmol) and 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4, 94 mg, 0.284 mmol) were dissolved in dichloromethane (2 mL). After reacting at room temperature for 2 hours, the reaction solution was concentrated under reduced pressure. The crude product was purified by Flash column (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (25-a, 30 mg, yield 33.5%). ESI[M+H] + =567.1,569.1

[0544] Step 2: Preparation of 7-(prop-1-yn-1-yl)-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (25)

[0545] 7-Bromo-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (25-a, 15 mg, 0.0265 mmol) was dissolved in toluene (2 mL), and 1-propynyl-tri-n-butyltin (21 μL, 0.066 mmol) and tetrakis(triphenylphosphine)palladium (6.1 mg, 5.30 μmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration, the mixture was concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] [50 min] The target product 7-(prop-1-yn-1-yl)-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (25, 1.65 mg, yield 11.8%) was prepared and purified to obtain ESI[M+H] + =527.2 1H NMR(600MHz,DMSO-d6)δ9.32(s,1H),8.70(s,1H),8.37(s,1H),8.01(s,1H),3.86(s,2 H),3.63–3.54(m,10H),2.34–2.25(m,2H),2.15(s,3H),1.94(dd,J=17.5,10.8Hz,2H).

[0546] Example 26: Preparation of N-(2-(4-((1R,3R)-3-((4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26)

[0547]

[0548] Step 1: Preparation of tert-butyl carbamate (1R,3R)-3-(4-(3-acetamido-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (26-a)

[0549] (1R,3R)-3-((tert-butoxycarbonyl)amino)cyclobutane-1-carboxylic acid (75 mg, 0.348 mmol) was dissolved in dichloromethane (5 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (132 mg, 0.348 mmol) and N,N-diisopropylethylamine (243 μL, 1.045 mmol) were added. After stirring for 10 minutes, N-(2-(piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (I-13, 400 mg, 0.348 mmol) was added, and the mixture was reacted at room temperature for 2 hours. The crude product, after being concentrated under reduced pressure, was purified by Flash column chromatography (10 g silica gel column, dichloromethane:methanol = 0–7%) to obtain the target product (1R,3R)-3-(4-(3-acetamido-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (26-a, 110 mg, yield 65.09%). ESI [M-56+H] + =485.4

[0550] Step 2: Preparation of N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide hydrochloride (26-b)

[0551] (1R,3R)-3-(4-(3-acetamido-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)carbamate tert-butyl (26-a, 110 mg, 0.227 mmol) was added to a 4M ethyl acetate hydrochloride solution (3 mL). After reacting at room temperature for 1 hour, the reaction solution was concentrated under reduced pressure, diluted with ethyl acetate, and concentrated under reduced pressure to obtain the target product N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide hydrochloride (26-b, 100 mg, yield 104.64%). ESI[M+H] + =386.3

[0552] Step 3: Preparation of N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26-c)

[0553] N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide hydrochloride (26-b, 100 mg, 0.237 mmol) was dissolved in water (2 mL), and sodium bicarbonate solid (40 mg, 0.474 mmol) was added. The mixture was stirred at room temperature for 5 minutes, and the pH of the reaction solution was measured to be 8-10. The mixture was concentrated under reduced pressure (dichloromethane:methanol = 10:1), slurried and filtered, and the filtrate was concentrated to obtain the target product N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26-c, 45 mg, yield 49.26%).

[0554] Step 4: Preparation of N-(2-(4-((1R,3R)-3-(7-bromo-4-oxo-3,4-dihydropyridino[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26-d)

[0555] N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26-c, 40 mg, 0.104 mmol) and 7-bromo-1-(bromomethyl)pyrido[3,4-d]pyridazin-4(3H)-one (I-4, 20 mg, 0.176 mmol) were dissolved in dichloromethane (2 mL) and reacted at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product N-(2-(4-((1R,3R)-3-(7-bromo-4-oxo-3,4-dihydropyridino[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26-d, 11 mg, yield 28.2%). ESI[M+H + =623.1,625.1

[0556] Step 5: Preparation of N-(2-(4-((1R,3R)-3-((4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26)

[0557] N-(2-(4-((1R,3R)-3-(7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26-d, 11 mg, 0.0177 mmol) was dissolved in 1,4-dioxane (2 mL), and 1-propynyl-tri-n-butyltin (14 μL, 0.0442 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 3.54 μmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration, the mixture was concentrated under reduced pressure. The crude product was then subjected to high performance liquid chromatography [Pack Column] 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 10%-100% over 50min] Preparation and purification yielded the target product N-(2-(4-((1R,3R)-3-((4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (26, 2.0 mg, yield 19.4%). ESI[M+H + =583.2 1H NMR(600MHz,DMSO-d6)δ12.87(s,1H),9.50(s,1H),9.32(s,1H),8.35(s,1H),8.30(s,1H),8.17(s,1H),8.01(s,1H),3. 87(s,2H),3.44(s,5H),3.21(dd,J=24.0,19.0Hz,6H),2.31–2.25(m,2H),2.14(s,3H),2.11(s,3H),1.97–1.91(m,2H).

[0558] Example 27: Preparation of 6-trifluoromethyl-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (27)

[0559]

[0560] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 21 mg, 0.0651 mmol) was dissolved in dichloromethane (2 mL), and 4-(bromomethyl)-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14, 20 mg, 0.651 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was purified by high-performance liquid chromatography (HPLC) [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 30min] after vacuum distillation to obtain the target product 6-trifluoromethyl-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (27, 5.58 mg, yield 15.82%). ESI [M+H] + =542.1, ESI[2M+H] + =1082.9 1 HNMR(600MHz,DMSO-d6)δ12.84(s,1H),8.70(s,2H),8.42(d,J=10.7Hz,2H),8.16–8.13(m,1 H),3.89(s,2H),3.80–3.75(m,3H),3.56–3.47(m,6H),3.38–3.33(m,2H),3.32–3.27(m,2H).

[0561] Example 28: Preparation of 6-(trifluoromethyl)-4-(((1R,3R)-3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (28)

[0562]

[0563] Dissolve ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-7, 21 mg, 0.0651 mmol) in dichloromethane (2 mL), add 4-(bromomethyl)-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14, 20 mg, 0.651 mmol), and react overnight at room temperature. The reaction solution was purified by high-performance liquid chromatography (HPLC) [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 30min] after vacuum distillation to obtain the target product 6-(trifluoromethyl)-4-(((1R,3R)-3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (28, 2.65 mg, yield 7.32%). ESI [M+H] + =555.8, ESI[2M+H] + =1111.0 1 HNMR (600MHz, DMSO-d6) δ12.80(s,1H),8.69(s,1H),8.50(s,1H),8.43(d,J=8.3Hz,1H),8.33(s,1H),8.14(d,J=9.1Hz,1H),3.96(s,2 H),3.83–3.77(m,3H),3.54(d,J=11.0Hz,4H),3.40–3.36(m,2H),3.25(dd,J=13.4,7.6Hz,2H),2.35–2.28(m,2H),2.00–1.93(m,2H).

[0564] Example 29: Preparation of 6-(trifluoromethyl)-4-(((1S,3S)-3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (29)

[0565]

[0566] Dissolve ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-9, 21 mg, 0.0651 mmol) in dichloromethane (2 mL), add 4-(bromomethyl)-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14, 20 mg, 0.651 mmol), and react overnight at room temperature. The reaction solution was purified by high-performance liquid chromatography (HPLC) [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 30min] after vacuum distillation to obtain the target product 6-(trifluoromethyl)-4-(((1S,3S)-3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (29 mg, 2.05 mg, yield 5.67%). ESI [M+H] + =556.1, ESI[2M+H] + =1111.0 1 HNMR(600MHz,DMSO-d6)δ12.80(s,1H),8.69(s,1H),8.48(s,1H),8.43(d,J=8.3Hz,1H),8.28(s,1H),8.13(d,J=8.2Hz,1H),3.96(s,2H),3.80–3.7 5(m,3H),3.52–3.49(m,2H),3.47–3.42(m,2H),3.19–3.11(m,2H),2.99– 2.90(m,2H),2.30(dd,J=17.9,8.3Hz,2H),1.83(dd,J=19.7,10.1Hz,2H).

[0567] Example 30: Preparation of N-(2-(4-(1-(4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30)

[0568]

[0569] Step 1: Preparation of tert-butyl 3-(4-(3-acetamido-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (30-a)

[0570] 1-(tert-Butoxycarbonyl)azacyclobutane-3-carboxylic acid (59 mg, 0.295 mmol) was dissolved in dichloromethane (3 mL), and N-(2-(piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (I-13, 80 mg, 0.246 mmol) and N,N-diisopropylethylamine (129 μL, 0.737 mmol) were added. The mixture was reacted for 5 minutes, and then 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (93 mg, 0.246 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was filtered and concentrated under reduced pressure, then purified by Flash column chromatography (petroleum ether: ethyl acetate = 0–80%) to obtain the target product tert-butyl 3-(4-(3-acetamido-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (30-a, 110 mg, yield 94.99%). ESI [M+H] + =472.1, ESI[M+H-56] + =415.7, ESI[M+H-100] + =371.7

[0571] Step 2: Preparation of N-(2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-b)

[0572] 3-(4-(3-acetamido-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (30-a, 110 mg, 0.233 mmol) was slowly added dropwise to a 4M solution of hydrogen chloride and ethyl acetate (2 mL) and stirred at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure, and water (1 mL) was added, followed by sodium bicarbonate (39 mg, 0.466 mg). The mixture was stirred for 5 minutes and the pH was adjusted to 8–9. The reaction solution was concentrated under reduced pressure with methanol, and then dissolved in a 10:1 solution of dichloromethane and sonicated. The solution was filtered. The filtrate was concentrated under reduced pressure to obtain the target product N-(2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-b, 72 mg, yield 83.14%). ESI [M+H] + =371.6

[0573] Step 3: Preparation of N-(2-(4-(1-(7-bromo-4-oxo-3,4-dihydropyridano[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-c)

[0574] N-(2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-b, 36 mg, 0.097 mmol) was dissolved in methanol (1 mL) and acetic acid (0.1 mL), followed by the addition of 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 30 mg, 0.118 mmol). The mixture was stirred at room temperature for 2 hours, followed by the addition of sodium cyanoborohydride (12 mg, 0.193 mmol), and the reaction was continued overnight at room temperature. The reaction solution was extracted with dichloromethane after the addition of water, and the organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure and then purified by Flash column chromatography (4 g silica gel column, dichloromethane:methanol = 0–9%) to obtain the target product N-(2-(4-(1-(7-bromo-4-oxo-3,4-dihydropyridino[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-c, 35 mg, yield 59.25%). ESI [M+H + =609.0,611.0

[0575] Step 4: Preparation of N-(2-(4-(1-(4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30)

[0576] N-(2-(4-(1-(7-bromo-4-oxo-3,4-dihydropyridino[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-c, 35 mg, 0.057 mmol), tributyl(prop-1-yn-1-yl)stanane (47 mg, 0.144 mmol), and tetra(triphenylphosphine)palladium (7 mg, 0.0057 mmol) were dissolved in 1,4-dioxane (2 mL) and reacted in a microwave oven at 100 °C for 1 hour under nitrogen protection. After the reaction was complete, the reaction solution was filtered and concentrated under reduced pressure. The crude product was purified by preparative liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 10%-90% over 50min] and then lyophilized to obtain the target product N-(2-(4-(1-(4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30, 2.99 mg, yield 9.16%). ESI [M+H] +=569.1 1 H NMR(600MHz,DMSO-d6)δ9.47(s,1H),9.31(s,1H),8.35(d,J=17.4Hz,1H),8.16(s,1H),7.95(s,1H),3.77(s,2H),3 .69(s,1H),3.55–3.49(m,3H),3.49–3.38(m,5H),3.27–3.15(m,4H),2.12(d,J=24.8Hz,3H),1.04(t,J=7.0Hz,3H).

[0577] Example 31: Preparation of 6-(trifluoromethoxy)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (31)

[0578]

[0579] 4-(bromomethyl)-6-(trifluoromethoxy)phthalazin-1(2H)-one (I-16, 20 mg, 0.0619 mmol) was dissolved in dichloromethane (2 mL), and then azirmonobutan-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 20 mg, 0.0619 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was purified by high-performance liquid chromatography (HPLC) [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 30min] after vacuum distillation to obtain the target product 6-(trifluoromethoxy)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (31, 5.33 mg, yield 15.45%). ESI [M+H] + =558.1, ESI[2M+H] + =1115.0 1 HNMR(600MHz,DMSO-d6)δ12.73(s,1H),8.68(s,1H),8.35(d,J=8.4Hz,1H),8.20(s,1H),8.01(s,1H) ,7.81(d,J=7.9Hz,1H),3.83–3.74(m,4H),3.56–3.51(m,4H),3.49(s,3H),3.34(s,2H),3.27(s,2H).

[0580] Example 32: Preparation of 6-(trifluoromethoxy)-4-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (32)

[0581]

[0582] 4-(bromomethyl)-6-(trifluoromethoxy)phthalazin-1(2H)-one (I-16, 20 mg, 0.0619 mmol) was dissolved in dichloromethane (2 mL), and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 20 mg, 0.0619 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was purified by high-performance liquid chromatography (HPLC) [Pack Column 30 ID * 250 mm * 10 μm; A: H₂O (0.1% FA), B: ACN, B%: 10%-100% over 30 min] after vacuum distillation to obtain the target product 6-(trifluoromethoxy)-4-(((1R, 3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (32, 0.73 mg, yield 2.06%). ESI [M+H] + =572.1, ESI[2M+H] + =1142.9 1 H NMR (600MHz, DMSO-d6) δ12.70(s,1H),8.69(s,1H),8.36(d,J=8.8Hz,1H),8.32(s,1H),8.09(s,1H),7.80(d,J=8.8Hz,1H),3.89(s,1H) ,3.79(d,J=3.8Hz,2H),3.56–3.48(m,4H),3.38(s,2H),3.28–3.20(m,2H),2.31(dd,J=10.5,6.0Hz,2H),1.96(dd,J=17.2,10.0Hz,2H).

[0583] Example 33: Preparation of 6-(trifluoromethoxy)-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (33)

[0584]

[0585] 4-(bromomethyl)-6-(trifluoromethoxy)phthalazin-1(2H)-one (I-16, 20 mg, 0.0619 mmol) was dissolved in dichloromethane (2 mL), and ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-9, 20 mg, 0.0619 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was purified by high-performance liquid chromatography (HPLC) [Pack Column 30 ID * 250 mm * 10 μm; A: H₂O (0.1% FA), B: ACN, B%: 10%-100% over 30 min] after vacuum distillation to obtain the target product 6-(trifluoromethoxy)-4-(((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)phthalazine-1(2H)-one (33, 0.94 mg, yield 2.66%). ESI [M+H] + =571.8 1 HNMR(600MHz,DMSO-d6)δ12.76(s,1H),9.70(d,J=3.1Hz,1H),9.14(d,J=6.7Hz,1H),8.82(s,1H),8.72(s,1H),8.29(s,1H),3.80(s,2H),3.67– 3.60(m,1H),3.57–3.53(m,1H),3.52–3.47(m,2H),3.46(s,2H),3.27(d ,J=7.2Hz,2H),3.25–3.16(m,2H),2.19–2.15(m,2H),2.04–1.85(m,2H).

[0586] Example 34: Preparation of 7-cyclobutoxy-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazine-4(3H)-one (34)

[0587]

[0588] ((1R,R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-7, 18 mg, 0.0544 mmol) was dissolved in methanol (4.5 mL), acetic acid (0.5 mL) and 7-cyclobutoxy-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-17, 24 mg, 0.0979 mmol) were added. After stirring at room temperature for 2 hours, sodium cyanoborohydride (6.8 mg, 0.109 mmol) was added under ice bath. After reacting at room temperature for 1 hour, the reaction solution was concentrated under reduced pressure. The crude product was purified by thin-layer chromatography (dichloromethane:methanol = 10:1), followed by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 40min] to obtain the target product 7-cyclobutoxy-1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazine-4(3H)-one (34, 1.19 mg, yield 3.9%). ESI [M+H] + =559.1 1 H NMR(600MHz,DMSO-d6)δ12.52(s,1H),9.07(s,1H),8.69(s,2H),7.24(s,1H) ,5.27–5.21(m,1H),3.88–3.75(m,5H),3.54(s,4H),3.38(s,1H),3.26–3.19( m,1H),2.47–2.35(m,2H),2.33–2.20(m,2H),2.16–2.04(m,2H),1.94(dd,J=1 7.3,9.9Hz,2H),1.80(dd,J=20.3,10.1Hz,2H),1.66(dd,J=18.7,9.0Hz,2H).

[0589] Example 35: Preparation of 6-(furan-2-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (35)

[0590]

[0591] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (22, 10 mg, 0.0181 mmol) was dissolved in toluene (2 mL), and tributyl(furan-2-yl)stanane (9 μL, 0.0272 mmol) and tetrakis(triphenylphosphine)palladium (2 mg, 0.00173 mmol) were added. The mixture was reacted overnight at 100 °C under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50min] to obtain the target product 6-(furan-2-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (35, 0.53 mg, yield 5.43%). ESI [M+H] + =540.1 1 H NMR (600MHz, DMSO-d6) δ12.56(s,1H),8.68(s,1H),8.39(s,1H),8.26(s,1H),8.24(d,J=8.3Hz,1H),8.14(d,J=8.3Hz ,1H),7.88(s,1H),7.27(s,1H),6.70(s,1H),3.84(s,3H),3.53(s,4H),3.50(s,2H),3.35(s,3H),3.31–3.26(m,3H).

[0592] Example 36: Preparation of 6-(thiazol-2-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (36)

[0593]

[0594] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (22, 17 mg, 0.0308 mmol) was dissolved in toluene (2 mL), and 2-(tributyltinyl)thiazole (19 μL, 0.0615 mmol) and tetrakis(triphenylphosphine)palladium (7 mg, 0.00606 mmol) were added. The mixture was reacted overnight at 100 °C under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50min] to obtain the target product 6-(thiazol-2-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (36, 0.69 mg, yield 4.03%). ESI [M+H] + =557.1 1 H NMR (600MHz, DMSO-d6) δ12.67(s,1H),8.68(s,1H),8.60(s,1H),8.35(d,J=4.3Hz,2H),8.33(d,J=8.3Hz,1H),8.06(d, J=2.9Hz,1H),7.94(d,J=3.0Hz,1H),3.87(s,2H),3.77(s,3H),3.52(s,4H),3.35(d,J=4.1Hz,3H),3.33–3.28(m,3H).

[0595] Example 37: Preparation of 7-(trifluoromethyl)-1-((3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (37)

[0596]

[0597] 4-O-7-(trifluoromethyl)-3,4-dihydropyrido[3,4-d]pyridazine-1-carboxaldehyde (I-18, 22 mg, 0.09 mmol) was dissolved in methanol (2 mL) and acetic acid (0.1 mL), and azirmonobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 31 mg, 0.1 mmol) was added. The mixture was stirred at room temperature for 2 hours. Then sodium cyanoborohydride (11 mg, 0.18 mmol) was added, and the reaction was carried out at room temperature for 6 hours. After the reaction was completed, the reaction solution was concentrated to obtain a crude product. The crude product was purified by high performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.01%TFA), B:ACN, B%: 10%-70% over 32min] to obtain the target product 7-(trifluoromethyl)-1-((3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (37, 2.45 mg, yield 5%). ESI [M+H] + =543.2 1 H NMR (600MHz, DMSO-d6) δ13.17(s,1H),9.56(s,1H),8.72(s,2H),8.43(s,1H),3.89(s,1H),3.82–3. 76(m,4H),3.55(dd,J=12.8,6.9Hz,3H),3.51(t,J=7.3Hz,2H),3.36(s,3H),3.28(t,J=7.1Hz,2H).

[0598] Example 38: Preparation of N-(2-(4-((1R,3R)-3-((4-oxo-7-(trifluoromethyl)-3,4-dihydrophthalazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethane)pyridin-3-yl)acetamide (38)

[0599]

[0600] Step 1: Preparation of tert-butyl ((1R,3R)-3-(4-(3-(methylcarbamoyl)-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (38-a)

[0601] (1R,3R)-3-(tert-Butoxycarbonyl)amino)cyclobutane-1-carboxylic acid (67 mg, 0.31 mmol) was dissolved in dichloromethane (6 mL), and O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (118 mg, 0.31 mmol) was added. The mixture was stirred for 10 minutes, and then N,N-diisopropylethylamine (162 μL, 0.93 mmol) and N-methyl-2-(piperazin-1-yl)-5-(trifluoro) Methyl nicotinamide (I-13, 100 mg, 0.31 mmol) was reacted overnight at room temperature. The reaction solution was then concentrated under reduced pressure and purified by Flash column chromatography (10 g silica gel column, petroleum ether: ethyl acetate = 1:2) to obtain the target product tert-butyl ((1R,3R)-3-(4-(3-(methylcarbamoyl)-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (38-a, 165 mg, yield 109.78%). ESI [M+H] + =486.0

[0602] Step 2: Preparation of 2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-N-methyl-5-(trifluoromethyl)nicotinamide (38-b)

[0603] Tert-butyl((1R,3R)-3-(4-(3-(methylcarbamoyl)-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)carbamate (38-a, 165 mg, 0.34 mmol) was dissolved in 4M ethyl acetate (3 mL). After reacting at room temperature for 2 hours, the solution was concentrated under reduced pressure. Water (1 mL) was added, and the pH was adjusted to 8 with sodium bicarbonate. The solution was extracted with dichloromethane:methanol = 10:1. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to give the target product 2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-N-methyl-5-(trifluoromethyl)nicotinamide (38-b, 130 mg, yield 99.24%). ESI[M+H] + =386.0

[0604] Step 3: Preparation of N-(2-(4-((1R,3R)-3-((4-oxo-7-(trifluoromethyl)-3,4-dihydrophthalazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethane)pyridin-3-yl)acetamide (38)

[0605] 4-(bromomethyl)-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14, 25 mg, 0.081 mmol) was dissolved in dichloromethane (2 mL), and N-(2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (38-b, 40 mg, 0.1 mmol) was added and stirred overnight at room temperature. After the reaction was completed, the reaction solution was concentrated to obtain a crude product. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.01%TFA), B:ACN, B%: 10%-70% over 35min] to obtain the target product N-(2-(4-((1R,3R)-3-((4-oxo-7-(trifluoromethyl)-3,4-dihydrophthalazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethane)pyridin-3-yl)acetamide (38, 1.24 mg, yield 2.5%). ESI [M+H] + =612.2 1 H NMR (600MHz, DMSO-d6) δ12.78(s,1H),9.45(s,1H),8.54(s,1H),8.43(d,J=8.3Hz,1H),8.38(s,1H),8.21(s,1H),8.14(d, J=8.5Hz,1H),3.96(s,2H),3.63(s,2H),3.46(s,2H),3.24(s,6H),2.31(s,2H),2.12(s,3H),1.96(dd,J=16.7,9.9Hz,2H).

[0606] Example 39: Preparation of 7-(trifluoromethyl)-1-(((1R,3R)-3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazine-4(3H)-one (39)

[0607]

[0608] 4-O-7-(trifluoromethyl)-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-18, 27 mg, 0.11 mmol) was dissolved in methanol (2 mL) and acetic acid (0.1 mL), and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 44 mg, 0.13 mmol) was added. The mixture was stirred at room temperature for 2 hours. Then sodium cyanoborohydride (14 mg, 0.22 mmol) was added, and the reaction was carried out at room temperature for 6 hours. After the reaction was completed, the reaction solution was concentrated to obtain a crude product. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.01%TFA), B:ACN, B%: 10%-70% over 32min] to obtain the target product 7-(trifluoromethyl)-1-(((1R,3R)-3-(4-(5-(trifluoromethane)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazine-4(3H)-one (39, 10.91 mg, yield 17.8%). ESI [M+H] + =557.2 1 H NMR(600MHz,DMSO-d6)δ13.14(s,1H),9.57(s,1H),8.72(s,2H),8.50(s,1H),3.97(s,2H),3.8 1(d,J=3.6Hz,4H),3.55(s,2H),3.31–3.21(m,4H),2.32(s,2H),1.96(dd,J=17.4,9.4Hz,2H).

[0609] Example 40: Preparation of 7-cyclopropyl-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (40)

[0610]

[0611] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 10 mg, 0.0181 mmol) was dissolved in 1,4-dioxane (1 mL) and water (0.2 mL). Under nitrogen protection, potassium carbonate (14 mg, 0.633 mmol), cyclopropylboronic acid (3 mg, 0.0271 mmol), palladium acetate (0.2 mg, 0.95 μmol), and tricyclohexylphosphine (0.5 mg, 1.81 μmol) were added, and the mixture was reacted overnight in an oil bath at 110 °C. The reaction solution was cooled, filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 50min] to obtain the target product 7-cyclopropyl-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (40, 0.57 mg, yield 6.13%). ESI [M+H] + =515.30 1 H NMR (600MHz, DMSO-d6) δ8.68(s,1H),8.38(s,2H),7.81(s,1H),3.77(s,4H),3.54(s,4H),3.51–3.46(m,2H),3.43(d,J=7. 5Hz,1H),3.35(s,2H),3.30–3.24(m,2H),2.36–2.31(m,1H),1.08(dd,J=30.0,7.5Hz,2H),0.82(dd,J=17.8,10.4Hz,2H).

[0612] Example 41: Preparation of N-(2-(4-(1-(4-oxo-7-(trifluoromethyl)-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethane)pyridin-3-yl)acetamide (41)

[0613]

[0614] 4-(bromomethyl)-6-(trifluoromethyl)phthalazin-1(2H)-one (I-14, 20 mg, 0.065 mmol) was dissolved in dichloromethane (2 mL), and N-(2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-b, 40 mg, 0.1 mmol) was added and stirred overnight at room temperature. After the reaction was completed, the reaction solution was concentrated to obtain a crude product. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.01%TFA), B:ACN, B%: 10%-70% over 31min] to obtain the target product N-(2-(4-(1-(4-oxo-7-(trifluoromethyl)-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethane)pyridin-3-yl)acetamide (41, 0.7 mg, yield 1.8%). ESI [M+H] + =598.2 1 H NMR (600MHz, DMSO-d6) δ12.82(s,1H),9.45(s,1H),8.45(s,1H),8.43(d,J=8.3Hz,1H),8.37(s,1H),8.20(s,1H),8.15(dd,J=8.5,1.8Hz,1H),3.87( s,2H),3.62(t,J=5.0Hz,2H),3.55(q,J=7.7Hz,1H),3.49(t,J=7.4Hz,2H) ,3.44–3.41(m,2H),3.27(d,J=7.2Hz,2H),3.28–3.21(m,4H),2.11(s,3H).

[0615] Example 42: Preparation of 7-(cyclohexylmethyl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (42)

[0616]

[0617] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 15 mg, 0.027 mmol), (cyclohexylmethyl)boronic acid (8 mg, 0.004 mmol) and potassium carbonate (11 mg, 0.081 mmol) were dissolved in 1,4-dioxane (2 mL) and water (0.4 mL), and palladium acetate (1 mg, 0.003 mmol) and tricyclohexylphosphine (2 mg, 0.006 mmol) were added. The mixture was stirred at 110 °C for 16 hours. After the reaction was completed, the reaction solution was filtered through diatomaceous earth and concentrated to obtain a crude product. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.01%TFA), B:ACN, B%: 10%-70% over 32min] to obtain the target product 7-(cyclohexylmethyl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (42, 0.89 mg, yield 5.78%). ESI [M+H] + =571.3 1 H NMR (600MHz, DMSO-d6) δ12.73(s,1H),8.73(s,1H),8.70(s,2H),8.31(d,J=5.4 Hz,1H),4.33–4.30(m,2H),4.24–4.21(m,2H),3.89(s,2H),3.85(s,2H),3.77(d ,J=9.8Hz,5H),3.68(d,J=3.7Hz,1H),3.60(s,2H),3.53(d,J=3.5Hz,3H),3.49– 3.46(m,3H),1.75–1.71(m,2H),1.64(d,J=12.3Hz,2H),1.59(d,J=12.3Hz,2H).

[0618] Example 43: Preparation of 7-(cyclobutylamino)-1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (43)

[0619]

[0620] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 20 mg, 0.036 mmol), tris(dibenzylidene indacetone)palladium (4 mg, 0.004 mmol), cesium carbonate (35 mg, 0.108 mmol), 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (3.4 mg, 0.007 mmol) and aminocyclobutane (7 μL, 0.072 mmol) were dissolved in 1,4-dioxane (4 mL) and stirred at 100 °C for 16 hours. After the reaction was completed, the reaction solution was filtered through diatomaceous earth and concentrated to obtain a crude product. The crude product was purified by high-performance liquid chromatography [Pack Column 30 ID*250mm*10μm; A:H2O (0.01% TFA), B:ACN, B%: 10%-70% over 32min] to obtain the target product 7-(cyclobutylamino)-1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (43, 0.44 mg, yield 2.25%). ESI [M+H] + =544.2 1 H NMR (600MHz, DMSO-d6) δ12.09(s,1H),8.87(s,1H),8.72(s,2H),7.84(d,J=6.8Hz,1H),3.80(s,3H),3.62(s,2H ),3.55(s,3H),3.51(d,J=7.4Hz,1H),3.47(s,3H),2.31(d,J=7.5Hz,3H),1.98–1.89(m,3H),1.76–1.65(m,4H).

[0621] Example 44: Preparation of 6-(furan-3-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (44)

[0622]

[0623] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (22, 15 mg, 0.0272 mmol) was dissolved in toluene (1.5 mL) and methanol (0.5 mL), and furan-3-ylboronic acid (3 mg, 0.0268 mmol), tetrakis(triphenylphosphine)palladium (5 mg, 0.00433 mmol), and sodium carbonate (6 mg, 0.0566 mmol) were added. The mixture was reacted at 80 °C for 4 hours under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30 ID*250mm*10μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over 50 min] to obtain the target product 6-(furan-3-yl)-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazin-1(2H)-one (44, 0.52 mg, yield 3.55%). ESI [M+H] + =540.3 1 H NMR (600MHz, DMSO-d6) δ12.50(s,1H),8.72(s,1H),8.46(s,1H),8.39(s,1H),8.21(d,J=8.5Hz,2H),8.08(d,J =8.3Hz,1H),7.86(s,1H),7.17(s,1H),3.87(s,2H),3.83–3.77(m,6H),3.54(s,2H),3.53(s,4H),3.51(s,1H).

[0624] Example 45: Preparation of 7-(cyclopentylmethyl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (45)

[0625]

[0626] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 15 mg, 0.027 mmol), (cyclopentylmethyl)boronic acid (7 mg, 0.004 mmol) and potassium carbonate (11 mg, 0.081 mmol) were dissolved in 1,4-dioxane (2 mL) and water (0.4 mL), and palladium acetate (1 mg, 0.003 mmol) and tricyclohexylphosphine (2 mg, 0.006 mmol) were added. The mixture was stirred at 110 °C for 16 hours. After the reaction was complete, the reaction solution was filtered through diatomaceous earth and concentrated to obtain a crude product. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.01%TFA), B:ACN, B%: 10%-70% over 32min] to obtain the target product 7-(cyclopentylmethyl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (45, 0.53 mg, yield 3.5%). ESI [M+H] + =557.3 1 H NMR (600MHz, DMSO-d6) δ12.24(s,1H),8.75(s,2H),8.72(s,2H),4.33(t,J=8.6Hz,2H),4.24(t,J=7.2Hz,2H),3.99(t,J=7.7Hz,1H),3.90(t,J= 5.3Hz,2H),3.87(t,J=5.4Hz,2H),3.81–3.78(m,5H),3.70(d,J=3.6Hz,2H),3.62(t,J=5.3Hz,2H),3.54(d,J=6.3Hz,4H),3.50(d,J=6.4Hz,4H).

[0627] Example 46: Preparation of N-(2-(4-(1-((7-cyano-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (46)

[0628]

[0629] Step 1: Preparation of N-(2-(4-(1-(7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (46-a)

[0630] N-(2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (30-b, 30 mg, 0.081 mmol) was dissolved in dichloromethane (0.5 mL), methanol (0.5 mL) and water (0.5 mL), and 6-bromo-4-bromomethylphthalazin-1(2H)-one (I-1, 40 mg, 0.126 mmol) was added and stirred overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the crude product was purified by thin-layer chromatography using silica gel plates (dichloromethane:methanol = 10:1) to give the target product N-(2-(4-(1-(7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (46-a, 25 mg, yield 32.68%). ESI [M+H] + =608.4,610.4

[0631] Step 2: Preparation of N-(2-(4-(1-((7-cyano-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (46)

[0632] N-(2-(4-(1-(7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (46-a, 25 mg, 0.0411 mmol) was dissolved in N,N-dimethylformamide (2 mL), and zinc cyanide (8 mg, 0.0657 mmol) and tetrakis(triphenylphosphine)palladium (6 mg, 4.93 μmol) were added. The mixture was then reacted in a microwave oven at 110 °C for 1 hour under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-80% over 45min] to obtain the target product N-(2-(4-(1-((7-cyano-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)pyridin-3-yl)acetamide (46, 1.19 mg, yield 5.23%). ESI [M+H] + =555.10 1H NMR (400MHz, DMSO-d6) δ12.85(s,1H),9.47(s,1H),8.65(s,1H),8.36(dd,J=9.0,4.6Hz,2H),8.23–8.17(m,2H),3.83(s,2 H),3.65–3.59(m,2H),3.58–3.53(m,1H),3.48(dd,J=11.7,4.2Hz,2H),3.45–3.41(m,2H),3.28–3.17(m,6H),2.11(s,3H).

[0633] Example 47: Preparation of 4-((3-fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1-oxo-1,2-dihydrophthalazine-6-onitrile (47)

[0634]

[0635] Step 1: Preparation of (3-fluorozacriane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (47-a)

[0636] 6-Bromo-4-(bromomethyl)phthalazin-1(2H)-one (I-1, 24 mg, 0.0759 mmol) was dissolved in dichloromethane (5 mL), and (3-fluorozahexacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-19, 35 mg, 0.114 mmol) was added. The reaction was carried out at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash (dichloromethane:methanol = 10:1) to obtain the target product (3-fluorozahexacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (47-a, 11 mg, yield 23.3%). ESI [M+H] + =570.1,572.1

[0637] Step 2: Preparation of 4-((3-fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1-oxo-1,2-dihydrophthalazine-6-onitrile (47)

[0638] (3-fluoroazacyclobutane-3-yl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (47-a, 11 mg, 0.0615 mmol) was dissolved in N,N-dimethylformamide (2 mL), and zinc cyanide (11.5 mg, 0.0984 mmol) and tetrakis(triphenylphosphine)palladium (8.5 mg, 7.38 μmol) were added. The reaction was carried out overnight at 110 °C under nitrogen protection. The reaction solution was filtered and concentrated under reduced pressure. The crude product was purified by [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-40% over 30min] to obtain the target product 4-((3-fluoro-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1-oxo-1,2-dihydrophthalazine-6-onitrile (47, 1.14 mg, yield 3.6%). ESI [M+H] + =517.2

[0639] Example 48: Preparation of 7-(thiazol-2-yl)-1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (48)

[0640]

[0641] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 20 mg, 0.0361 mmol) was dissolved in 1,4-dioxane (2 mL), and 2-(tributyltinyl)thiazole (27 mg, 0.0723 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 3.61 μmol) were added under nitrogen protection. The mixture was reacted overnight in an oil bath at 100 °C. The reaction solution was cooled and filtered. The filtrate was concentrated under reduced pressure. The crude product was purified twice by high-performance liquid chromatography [Pack Column 20 ID * 250 mm * 10 μm; A: H₂O (0.1% FA), B: ACN, B%: 5%-100% over 50 min] to obtain the target product 7-(thiazol-2-yl)-1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (48, 1.06 mg, yield 5.26%). ESI [M+H] + =557.80 1HNMR(600MHz,DMSO-d6)δ12.96(s,1H),9.46(s,1H),8.71(s,2H),8.61(s,1H),8.14(d,J=2.9Hz,1H),8.04(d,J=2.9Hz,1 H),3.87(s,2H),3.82–3.76(m,4H),3.59–3.56(m,1H),3.53(dd,J=14.8,8.0Hz,4H),3.43(s,2H),3.30(d,J=6.7Hz,2H).

[0642] Example 49: Preparation of 2-(4-((1R,3R)-3-((4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49)

[0643]

[0644] Step 1: Preparation of tert-butyl carbamate (1R,3R)-3-(4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (49-a)

[0645] Dissolve (1R,3R)-3-((tert-butoxycarbonyl)amino)cyclobutane-1-carboxylic acid (73.6 mg, 0.342 mmol) in N,N-dimethylformamide (3 mL), add 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (130 mg, 0.342 mmol) and N,N-diisopropylethylamine (179 μL, 1.03 mmol), stir in an ice bath for 20 minutes, then add 2-(piperazin-1-yl)- 5-(trifluoromethyl)nicotinic acid nitrile hydrochloride (I-20, 100 mg, 0.342 mmol) was reacted at room temperature for 4 hours. Water (20 mL) was then added dropwise to the reaction solution, resulting in the precipitation of a white solid. The mixture was filtered, the filter cake was washed with water, collected, and concentrated under reduced pressure to obtain the target product (1R,3R)-3-(4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate tert-butyl ester (49-a, 131 mg, yield 84.5%). ESI [M-56+H] + =398.2

[0646] Step 2: Preparation of 2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinonitrile (49-b)

[0647] (1R,3R)-3-(4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)carbamate tert-butyl ester (49-a, 13 mg, 0.289 mmol) was dissolved in ethyl acetate (2 mL), and 4M ethyl acetate hydrochloride solution (3 mL) was added. After reacting at room temperature for 3 hours, the mixture was concentrated under reduced pressure, and water (1 mL) was added. The pH was adjusted to 8 with sodium bicarbonate aqueous solution, and the mixture was extracted with dichloromethane:methanol = 8:1. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to obtain the target product 2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinonitrile (49-b, 118 mg, crude product). ESI[M+H] + =354.3

[0648] Step 3: Preparation of 2-(4-((1R,3R)-3-((7-bromo-4-oxo-3,4-dihydropyridano[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49-c)

[0649] 2-(4-((1R,3R)-3-aminocyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49-b, 40 mg, 0.157 mmol) and 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 39 mg, 0.11 mmol) were dissolved in methanol (1.8 mL) and acetic acid (0.2 mL). After stirring at room temperature for 2 hours, sodium cyanoborohydride (20 mg, 0.318 mmol) was added, and the reaction was continued at room temperature for another 2 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 2-(4-((1R,3R)-3-((7-bromo-4-oxo-3,4-dihydropyridano[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49-c, 60 mg, yield 64.4%). ESI[M+H + =591.1,593.0

[0650] Step 4: Preparation of 2-(4-((1R,3R)-3-((4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49)

[0651] 2-(4-((1R,3R)-3-((7-bromo-4-oxo-3,4-dihydropyridino[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49-c, 15 mg, 0.0254 mmol) was dissolved in toluene (2 mL), and tributyl(prop-1-yn-1-yl)stanane (12 μL, 0.038 mmol) and tetrakis(triphenylphosphine)palladium (3 mg, 0.0026 mmol) were added. The mixture was reacted overnight at 100 °C under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30 ID * 250 mm * 10 μm; A: H₂O (0.1% FA), B: ACN, B%: 10%-100% over 50 min] to obtain the target product: 2-(4-((1R, 3R)-3-((4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)amino)cyclobutane-1-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (49, 0.58 mg, yield 4.16%). ESI [M+H] + =551.2 1 H NMR(600MHz,DMSO-d6)δ12.86(s,1H),9.33(s,1H),8.71(s,1H),8.53(s,1H),8.40(s,1H),8.04(s,1H),3.87(s,1H),3.82(d, J=4.0Hz,3H),3.61(s,2H),3.48(s,3H),3.23(dd,J=13.4,5.9Hz,3H),2.31(s,2H),2.16(s,3H),1.94(dd,J=18.1,9.6Hz,2H).

[0652] Example 50: Preparation of 4-oxo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-3,4-dihydropyrido[3,4-d]pyridazine-7-onitrile (50)

[0653]

[0654] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 30 mg, 0.0542 mmol) was dissolved in N,N-dimethylformamide (3 mL), and zinc cyanide (13 mg, 0.111 mmol) and tetrakis(triphenylphosphine)palladium (6 mg, 5.42 μmol) were added under nitrogen protection. The mixture was then microwaved at 100 °C for 1 hour. The reaction solution was cooled, filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 20ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 45min] to obtain the target product 4-oxo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-3,4-dihydropyrido[3,4-d]pyridazine-7-onitrile (50, 3.12 mg, yield 12.80%). ESI [M+H] + =500.20 1 H NMR(600MHz,DMSO-d6)δ9.49(s,1H),8.71(s,2H),8.69(s,1H),3.83(s,2H),3 .82–3.77(m,4H),3.56–3.53(m,3H),3.52–3.49(m,3H),3.28(t,J=6.9Hz,3H).

[0655] Example 51: Preparation of 2-(4-(1-(4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinonitrile (51)

[0656]

[0657] Step 1: Preparation of tert-butyl 3-(4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (51-a)

[0658] 1-(tert-Butoxycarbonyl)azacyclobutane-3-carboxylic acid (83 mg, 0.411 mmol) and 2-(7-azabenzotriazole)-N,N,N,N-tetramethylurea hexafluorophosphate (156.3 mg, 0.411 mmol) were dissolved in dichloromethane (10 mL). N,N-diisopropylethylamine (216 μL, 1.23 mmol) was added under ice bath conditions. After stirring under ice bath conditions for 30 minutes, 2-(piperazin-1-yl)-5-(trifluoromethyl)nicotinamide hydrochloride (I-20, 120 mg, 0.411 mmol) was added. The reaction was carried out at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain the target product, tert-butyl 3-(4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylate (51-a, 93 mg, yield 51.9%). ESI [M-56+H] + =384.1

[0659] Step 2: Preparation of 2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (51-b)

[0660] 3-(4-(3-cyano-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (51-a, 93 mg, 0.121 mmol) was dissolved in ethyl acetate (2 mL), and 4M ethyl acetate hydrochloride solution (3 mL) was added. After reacting at room temperature for 3 hours, the reaction solution was concentrated under reduced pressure, dichloromethane was added, and the pH was adjusted to 8 with triethylamine. The crude product was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 8:1) to obtain the target product 2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (51-b, 36 mg, yield 50.1%). ESI [M+H] + =340.1

[0661] Step 3: Preparation of 2-(4-(1-((7-bromo-4-oxo-3,4-dihydropyridano[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (51-c)

[0662] 2-(4-(azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (51-b, 36 mg, 0.106 mmol) was dissolved in methanol (4.5 mL), acetic acid (0.5 mL) and 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 27 mg, 0.106 mmol) were added. After stirring at room temperature for 2 hours, sodium cyanoborohydride (13.3 mg, 0.212 mmol) was added under ice bath. After reacting at room temperature for 1 hour, the reaction solution was concentrated under reduced pressure. The crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 2-(4-(1-((7-bromo-4-oxo-3,4-dihydropyridano[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (51-c, 38 mg, yield 62.2%). ESI[M+H] + =577.1,579.1

[0663] Step 4: Preparation of 2-(4-(1-(4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinonitrile (51)

[0664] 2-(4-(1-((7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinamide (51-c, 38 mg, 0.066 mmol) was dissolved in toluene (2 mL), and 1-propynyl-tri-n-butyltin (33 μL, 0.0989 mmol) and tetrakis(triphenylphosphine)palladium (7.6 mg, 6.60 μmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. The reaction solution was filtered and concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] After preparation and purification for 50 min, the product was further purified by thin-layer chromatography (dichloromethane:methanol = 10:1) to obtain the target product 2-(4-(1-(4-oxo-7-(prop-1-yn-1-yl)-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)methyl)azacyclobutane-3-carbonyl)piperazin-1-yl)-5-(trifluoromethyl)nicotinonitrile (51, 1.19 mg, yield 3.36%). ESI [M+H] + =537.2 1H NMR (600MHz, DMSO-d6) δ9.03(s,1H),7.95(s,1H),7.72(dd,J=5.6,3.4Hz,1H),7.67(dd,J=5.8,3.3Hz,1H),4.22(t,J=6.6 Hz,1H),2.89-2.80(m,4H),2.73-2.67(m,4H),1.67-1.60(m,2H),1.39(dd,J=16.1,8.5Hz,2H),1.33(s,2H),1.22(s,3H).

[0665] Example 52: Preparation of 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (52)

[0666]

[0667] Step 1: Preparation of tert-butyl 3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (52-a)

[0668] 1-(tert-Butoxycarbonyl)azacyclobutane-3-carboxylic acid (100 mg, 0.497 mmol), 2-(7-azabenzotriazole)-N,N,N,N-tetramethylurea hexafluorophosphate (189 mg, 0.497 mmol), and diisopropylethylamine (260 μL, 1.491 mmol) were dissolved in dichloromethane (4 mL) and reacted for 20 minutes. Finally, 1-(5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-22, 146 mg, 0.646 mmol) was added, and the reaction was stirred overnight at room temperature. After the reaction was completed, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 0–50%) to obtain the target product 3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (52-a, 161 mg, yield 78.17%). ESI [M+H-56] + =359.2

[0669] Step 2: Preparation of azirmonobutane-3-yl(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (52-b)

[0670] 3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (52-a, 161 mg, 0.388 mmol) was dissolved in ethyl acetate (2 mL), and 4M ethyl acetate hydrochloride solution (4 mL) was added under ice bath conditions. After reacting at room temperature for 2 hours, the reaction solution was concentrated under reduced pressure and purified by thin-layer chromatography on silica gel (dichloromethane:methanol = 15:1) to give the target product heterocyclobutane-3-yl(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (52-b, 60 mg, yield 49.2%). ESI [M+H] + =315.2

[0671] Step 3: Preparation of azirmonobutane-3-yl(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone (52-c)

[0672] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone hydrochloride (52-b, 1 g, 2.854 mmol) was dissolved in water (8 mL), the pH was adjusted to 8 with sodium bicarbonate aqueous solution, and the solution was extracted with dichloromethane:methanol = 10:1. The organic phase was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to obtain the target product, azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone (52-c, 500 mg, yield 55.72%). ESI [M+H] + =315.2

[0673] Step 4: Preparation of 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (52-d)

[0674] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone (52-c, 26 mg, 0.0828 mmol) and 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 30 mg, 0.118 mmol) were dissolved in methanol (4 mL) and acetic acid (0.4 mL). After stirring at room temperature for 2 hours, sodium cyanoborohydride (15 mg, 0.239 mmol) was added, and the reaction was continued overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 20:1) to obtain the target product 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (52-d, 25 mg, yield 38.46%). ESI[M+H + =552.0,553.8

[0675] Step 3: Preparation of 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (52)

[0676] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (52-d, 25 mg, 0.0453 mmol) was dissolved in toluene (2 mL), and tributyl(prop-1-yn-1-yl)stanane (21 μL, 0.0679 mmol) and tetrakis(triphenylphosphine)palladium (5 mg, 0.00433 mmol) were added. The mixture was reacted overnight at 100 °C under nitrogen protection. After filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (52, 1.16 mg, yield 5.04%). ESI [M+H] + =512.1 1H NMR (600MHz, DMSO-d6) δ12.89(s,1H),9.32(s,1H),8.41(s,1H),8.38(s,1H),7.99(s,1H),7.81(d,J=8.9Hz,1H),6.95(d,J=9.0 Hz,1H),3.78(s,1H),3.61(s,3H),3.57–3.53(m,3H),3.49–3.45(m,4H),3.26(dd,J=14.6,7.2Hz,3H),2.17(s,2H),1.23(s,1H).

[0677] Example 53: Preparation of 7-(1-methyl-1H-pyrazol-4-yl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (53)

[0678]

[0679] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 15 mg, 0.0271 mmol) was dissolved in toluene (1.5 mL) and methanol (0.5 mL), and (1-methyl-1H-pyrazol-4-yl)boronic acid (3 mg, 0.0238 mmol), tetrakis(triphenylphosphine)palladium (5 mg, 0.00433 mmol), and sodium carbonate (6 mg, 0.0566 mmol) were added. The mixture was reacted at 80 °C for 4 hours under nitrogen protection. After filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 7-(1-methyl-1H-pyrazol-4-yl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (53, 1.01 mg, yield 6.73%). ESI [M+H] + =555.2 1H NMR(600MHz,DMSO-d6)δ12.71(s,1H),9.34(s,1H),8.72(s,1H),8.51(s,1H),8.37(s,1H),8.19(s, 1H),8.05(s,1H),3.93(s,3H),3.83(s,2H),3.79(dd,J=11.4,6.5Hz,5H),3.54(s,5H),3.30(s,3H).

[0680] Example 54: Preparation of 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (54)

[0681]

[0682] Step 1: Preparation of tert-butyl 3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid (54-a)

[0683] 1-(tert-Butoxycarbonyl)azacyclobutane-3-carboxylic acid (120 mg, 0.596 mmol) and 2-(7-azabenzotriazole)-N,N,N,N-tetramethylurea hexafluorophosphate (227 mg, 0.596 mmol) were dissolved in dichloromethane (10 mL). N,N-diisopropylethylamine (313 μL, 1.79 mmol) was added under ice bath conditions. After stirring under ice bath conditions for 30 minutes, 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrazine hydrochloride (I-21, 166 mg, 0.596 mmol) was added. The reaction was carried out at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product 3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (54-a, 109 mg, yield 44.1%). ESI [M-56+H] + =360.1

[0684] Step 2: Preparation of azirmonobutane-3-yl(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-yl)methyl ketone (54-b)

[0685] 3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (54-a, 109 mg, 0.262 mmol) was dissolved in ethyl acetate (2 mL), and 4M ethyl acetate hydrochloride solution (3 mL) was added. After reacting at room temperature for 3 hours, the reaction solution was concentrated under reduced pressure, and dichloromethane was added. The pH was adjusted to 8 with triethylamine. The crude product was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 8:1) to obtain the target product, azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-yl)methyl ketone (54-b, 36 mg, yield 43.6%). ESI [M+H] + =315.9

[0686] Step 3: Preparation of 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (54-c)

[0687] Azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-yl) methyl ketone (54-b, 26 mg, 0.103 mmol) was dissolved in methanol (4.5 mL), acetic acid (0.5 mL) and 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 27 mg, 0.0857 mmol) were added. After stirring at room temperature for 2 hours, sodium cyanoborohydride (10.8 mg, 0.171 mmol) was added under ice bath. After reacting at room temperature for 1 hour, the reaction solution was concentrated under reduced pressure. The crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (54-c, 30 mg, yield 63.4%). ESI[M+H + =553.1,555.1

[0688] Step 4: Preparation of 7-(prop-1-yn-1-yl)-1-((3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (54)

[0689] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (54-c, 30 mg, 0.0543 mmol) was dissolved in toluene (2 mL), and 1-propynyl-tri-n-butyltin (27 μL, 0.0815 mmol) and tetrakis(triphenylphosphine)palladium (6.3 mg, 5.43 μmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. The reaction solution was filtered and concentrated under reduced pressure. The crude product was subjected to high performance liquid chromatography [Pack Column 30 ID*250 mm*10 μm; A: H2O (0.1% FA), B: ACN, B%: 10%-100% over] After preparation and purification for 50 min, the product was further purified by thin-layer chromatography (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-1-((3-(4-(5-(trifluoromethyl)pyrazin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (54, 1.55 mg, yield 5.7%). ESI [M+H] + =513.2 1 H NMR(600MHz,DMSO-d6)δ12.88(s,1H),9.33(s,1H),8.50(s,1H),8.42(s,1H),7.99(s,1H),3.78(s,2H),3.74–3.65 (m,4H),3.56(dd,J=16.4,7.3Hz,3H),3.48(t,J=7.4Hz,2H),3.43–3.38(m,2H),3.26(t,J=7.3Hz,2H),2.17(s,3H).

[0690] Example 55: Preparation of 1-(3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-7-(prop-1-yn-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one (55)

[0691]

[0692] Step 1: Preparation of tert-butyl 3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid (55-a)

[0693] 1-(tert-Butoxycarbonyl)azacyclobutane-3-carboxylic acid (60 mg, 0.299 mmol) was dissolved in dichloromethane (5 mL), and O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 0.299 mmol) was added. The mixture was stirred for 10 minutes, and then N,N-diisopropylethylamine (157 μL, 0.897 mmol) and 1-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-23, 89 mg, 0.299 mmol) were added. The reaction was stirred at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash silica gel column chromatography (petroleum ether: ethyl acetate = 0–50%) to obtain the target product 3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (55-a, 119 mg, yield 89.56%). ESI [M+H] + =445.0

[0694] Step 2: Preparation of azirmonobutane-3-yl(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (55-b)

[0695] 3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (55-a, 119 mg, 0.268 mmol) was dissolved in 4M ethyl acetate (3 mL) and reacted at room temperature for 1 hour. After the reaction was monitored to be complete, the reaction solution was diluted with dichloromethane several times and then concentrated under reduced pressure to obtain the target product, azacyclobutane-3-yl(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (55-b, 119 mg, yield 116.72%).

[0696] Step 3: Preparation of aziridine-3-yl(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone (55-c)

[0697] Azacyclobutane-3-yl(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone hydrochloride (55-b, 119 mg, 0.313 mmol) was dissolved in water (2 mL), and sodium bicarbonate (53 mg, 0.626 mmol) was added. The reaction was carried out at room temperature for 5 minutes. After monitoring the pH to 8-9, the reaction solution was concentrated under reduced pressure. The crude product was dissolved by sonication in a solution of dichloromethane:methanol = 10:1 and filtered. The filtrate was concentrated under reduced pressure to obtain the target product, azacyclobutane-3-yl(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone (55-c, 103 mg, yield 95.72%).

[0698] Step 4: Preparation of 7-bromo-1-((3-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (55-d)

[0699] Azacyclobutane-3-yl(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone (55-c, 81 mg, 0.235 mmol) and 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 60 mg, 0.236 mmol) were dissolved in methanol (4 mL) and acetic acid (0.4 mL). After stirring at room temperature for 2 hours, sodium cyanoborohydride (30 mg, 0.477 mmol) was added, and the reaction was continued overnight at room temperature. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 20:1) to obtain the target product 7-bromo-1-((3-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (55-d, 60 mg, yield 43.62%). ESI[M+H + =582.3,584.3

[0700] Step 5: Preparation of 1-(3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-7-(prop-1-yn-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one (55)

[0701] 7-Bromo-1-((3-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (55-d, 30 mg, 0.0515 mmol) was dissolved in toluene (2 mL), and tributyl(prop-1-yn-1-yl)stanane (24 μL, 0.0772 mmol) and tetrakis(triphenylphosphine)palladium (6 mg, 0.00519 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 1-(3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-7-(prop-1-yn-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one (55, 2.31 mg, yield 8.28%). ESI [M+H] + =542.4 1 H NMR(600MHz,DMSO-d6)δ9.32(s,1H),8.11(s,1H),7.98(s,1H),7.43(s,2H),3.87(s,5H),3. 78(d,J=7.9Hz,3H),3.54(d,J=4.4Hz,5H),3.48(s,1H),3.24(t,J=7.0Hz,4H),2.17(s,3H).

[0702] Example 56: Preparation of 7-(furan-3-yl)-1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (56)

[0703]

[0704] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 15 mg, 0.0271 mmol) was dissolved in toluene (1.5 mL) and methanol (0.5 mL), and furan-3-ylboronic acid (3 mg, 0.0268 mmol), tetrakis(triphenylphosphine)palladium (5 mg, 0.00433 mmol), and sodium carbonate (6 mg, 0.0566 mmol) were added. The mixture was reacted at 80 °C for 4 hours under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 7-(furan-3-yl)-1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (56, 1.18 mg, yield 8.05%). ESI [M+H] + =541.3 1 H NMR(600MHz,DMSO-d6)δ12.80(s,1H),9.39(s,1H),8.72(s,1H),8.56(s,1H),8.39(s,1H),8.13 (s,1H),7.88(s,1H),7.24(s,1H),3.86(s,2H),3.80(d,J=6.1Hz,4H),3.54(s,6H),3.30(s,3H).

[0705] Example 57: Preparation of 1-((1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)-7-(prop-1-yn-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one (57)

[0706]

[0707] Step 1: Preparation of tert-butyl carbamate (1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (57-a)

[0708] (1R,3R)-3-((tert-butoxycarbonyl)amino)cyclobutane-1-carboxylic acid (64 mg, 0.299 mmol) was dissolved in dichloromethane (5 mL), and O-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (114 mg, 0.299 mmol) was added. The mixture was stirred for 10 minutes, and then N,N-diisopropylethylamine (157 μL, 0.897 mmol) and 1-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine hydrochloride (I-23, 89 mg, 0.299 mmol) were added. The reaction was stirred at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash silica gel column chromatography (petroleum ether: ethyl acetate = 0–49%) to obtain the target product (1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)cyclobutyl)carbamate (57-a, 114 mg, yield 83.17%). ESI [M+H] + =459.0

[0709] Step 2: Preparation of ((1R,3R)-3-aminocyclobutyl)(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (57-b)

[0710] (1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)carbamate tert-butyl (57-a, 114 mg, 0.249 mmol) was dissolved in 4M ethyl acetate (3 mL) and reacted at room temperature for 1 hour. After the reaction was monitored to be complete, the reaction solution was diluted with dichloromethane several times and then concentrated under reduced pressure to obtain the target product ((1R,3R)-3-aminocyclobutyl)(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (57-b, 118 mg, yield 120.20%).

[0711] Step 3: Preparation of ((1R,3R)-3-aminocyclobutyl)(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone (57-c)

[0712] ((1R,3R)-3-aminocyclobutyl)(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone hydrochloride (57-b, 118 mg, 0.299 mmol) was dissolved in water (2 mL), and sodium bicarbonate (51 mg, 0.598 mmol) was added. The reaction was carried out at room temperature for 5 minutes. After monitoring the pH to 8-9, the reaction solution was concentrated under reduced pressure. The crude product was dissolved by sonication in a solution of dichloromethane:methanol = 10:1 and filtered. The filtrate was concentrated under reduced pressure to obtain the target product ((1R,3R)-3-aminocyclobutyl)(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl)methyl ketone (57-c, 106 mg, yield 98.97%).

[0713] Step 4: Preparation of 7-bromo-1-((1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (57-d)

[0714] ((1R,3R)-3-aminocyclobutyl)(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-yl) methyl ketone (57-c, 30 mg, 0.0837 mmol) and 7-bromo-4-oxo-3,4-dihydropyrido[3,4-d]pyridazin-1-carboxaldehyde (I-15, 30 mg, 0.118 mmol) were dissolved in methanol (3 mL) and acetic acid (0.3 mL). After stirring at room temperature for 2 hours, sodium cyanoborohydride (15 mg, 0.239 mmol) was added, and the reaction was continued at room temperature overnight. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 20:1) to obtain the target product 7-bromo-1-((1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (57-d, 30 mg, yield 42.6%). ESI[M+H + =596.3,598.3

[0715] Step 5: Preparation of 1-((1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)-7-(prop-1-yn-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one (57)

[0716] 7-Bromo-1-((1R,3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (57-d, 205 mg, 0.0335 mmol) was dissolved in toluene (2 mL), and tributyl(prop-1-yn-1-yl)stanane (15 μL, 0.0503 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.00346 mmol) were added. The reaction was carried out overnight at 100 °C under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30 ID * 250 mm * 10 μm; A: H₂O (0.1% FA), B: ACN, B%: 5%-100% over 50 min] to obtain the target product 1-((1R, 3R)-3-(4-(3-methoxy-5-(trifluoromethyl)pyridin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)methyl)-7-(prop-1-yn-1-yl)pyrido[3,4-d]pyridazin-4(3H)-one (57 mg, 1.77 mg, yield 9.51%). ESI [M+H] + =556.4 1 H NMR (600MHz, DMSO-d6) δ9.33(s,1H),8.29(s,1H),8.12(s,1H),8.03(s,1H),7.44(s,1H),3.87(d,J=7.9H z,5H),3.56(s,3H),3.22(dd,J=14.1,6.5Hz,6H),2.30(s,3H),2.16(s,3H),1.93(dd,J=17.5,9.8Hz,3H).

[0717] Example 58: Preparation of 7-(4-fluorophenyl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (58)

[0718]

[0719] 7-Bromo-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (11-a, 15 mg, 0.0271 mmol) was dissolved in toluene (1.5 mL) and methanol (0.5 mL), and (4-fluorophenyl)boronic acid (3.4 mg, 0.0243 mmol), tetrakis(triphenylphosphine)palladium (5 mg, 0.00433 mmol), and sodium carbonate (6 mg, 0.0566 mmol) were added. The reaction was carried out overnight at 80 °C under nitrogen protection. After filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 7-(4-fluorophenyl)-1-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)pyrido[3,4-d]pyridazin-4(3H)-one (58, 0.69 mg, yield 4.48%). ESI [M+H] + =569.4 1 H NMR (600MHz, DMSO-d6) δ12.86(s,1H),9.48(s,1H),8.72(s,1H),8.44(s,1H),8.41(s,1H),8.33(dd,J=8. 6,5.6Hz,2H),7.42(t,J=8.8Hz,2H),3.92(s,2H),3.79(dd,J=8.8,5.3Hz,5H),3.53(s,6H),3.30(s,2H).

[0720] Example 59: Preparation of 1-oxo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)ethyl)-1,2-dihydrophthalazine-6-onitrile (59)

[0721]

[0722] Step 1: Preparation of 6-bromo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)ethyl)phthalazin-1(2H)-one (59-a)

[0723] 6-Bromo-4-(1-Bromomethyl)phthalazin-1(2H)-one (I-24, 100 mg, 0.301 mmol) was dissolved in dichloromethane (4 mL), and aziridine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 105 mg, 0.331 mmol) and triethylamine (50 μL, 0.362 mmol) were added. The mixture was stirred at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)aziridine-1-yl)ethyl)phthalazin-1(2H)-one (59-a, 100 mg, yield 58.62%). ESI[M+H] + =566.3,568.3

[0724] Step 2: Preparation of 1-oxo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)ethyl)-1,2-dihydrophthalazine-6-onitrile (59)

[0725] 6-Bromo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)ethyl)phthalazin-1(2H)-one (59-a, 40 mg, 0.0706 mmol) was dissolved in N,N-dimethylformamide (4 mL), and zinc cyanide (12 mg, 0.102 mmol) and tetrakis(triphenylphosphine)palladium (12 mg, 0.0104 mmol) were added. The mixture was reacted overnight at 100 °C under nitrogen protection. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 1-oxo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)ethyl)-1,2-dihydrophthalazine-6-onitrile (59g, 1.06mg, yield 2.93%). ESI [M+H] + =513.3 1 H NMR(600MHz,DMSO-d6)δ12.88(s,1H),9.12(s,1H),8.71(s,1H),8.41–8.37(m,2H),8.21(d,J =8.3Hz,1H),3.83–3.73(m,6H),3.61–3.52(m,6H),3.20–3.16(m,2H),1.31(d,J=6.7Hz,3H).

[0726] Example 60: Preparation of 1-oxo-4-(2-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)prop-2-yl)-1,2-dihydrophthalazine-6-onitrile (60)

[0727]

[0728] Step 1: Preparation of 6-bromo-4-(2-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)prop-2-yl)phthalazin-1(2H)-one (60-a)

[0729] 6-Bromo-4-(2-bromoprop-2-yl)phthalazin-1(2H)-one (I-25, 76 mg, 50% purity, 0.110 mmol) was dissolved in dichloromethane (10 mL), and aziridine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 70 mg, 0.221 mmol) was added. The reaction was carried out at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-(2-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)aziridine-1-yl)prop-2-yl)phthalazin-1(2H)-one (60-a, 49 mg, yield 92.1%). ESI [M+H] + =580.2,582.2

[0730] Step 2: Preparation of 1-oxo-4-(2-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)prop-2-yl)-1,2-dihydrophthalazine-6-onitrile (60)

[0731] 6-Bromo-4-(2-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)prop-2-yl)phthalazin-1(2H)-one (60-a, 49 mg, 0.0846 mmol) was dissolved in N,N-dimethylformamide (2 mL), and zinc cyanide (20 mg, 0.169 mmol) and tetrakis(triphenylphosphine)palladium (19.5 mg, 16.9 μmol) were added. The reaction was carried out overnight at 110 °C under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1). The resulting product, 1-oxo-4-(2-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)propyl-2-yl)-1,2-dihydrophthalazin-6-onitrile (60 mg, 5.14 mg, yield 11.6%), was obtained. (ESI [M+H])+ =527.2 1 H NMR (600MHz, DMSO-d6) δ12.88(s,1H),9.72(s,1H),8.72(s,2H),8.38(d,J=8.2Hz,1H),8.20(d,J=8.2Hz,1H),3.84– 3.73(m,4H),3.60–3.54(m,2H),3.51(dd,J=14.9,7.4Hz,1H),3.42–3.36(m,4H),3.30(d,J=7.7Hz,2H),1.38(s,6H).

[0732] Example 61: Preparation of 1-oxo-4-(2-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)propyl-2-yl)-1,2-dihydrophthalazine-6-onitrile (61)

[0733]

[0734] Step 1: Preparation of 6-bromo-4-(2-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)propyl-2-yl)phthalazine-1(2H)-one (61-a)

[0735] 6-Bromo-4-(2-bromopropyl-2-yl)phthalazin-1(2H)-one (I-25, 88 mg, 50% purity, 0.128 mmol) was dissolved in dichloromethane (10 mL), and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 84 mg, 0.256 mmol) was added. The reaction was carried out at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-(2-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)cyclobutyl)amino)propyl-2-yl)phthalazin-1(2H)-one (61-a, 76 mg, yield 86.8%). ESI[M+H] + =594.2,596.2

[0736] Step 2: Preparation of 1-oxo-4-(2-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)propyl-2-yl)-1,2-dihydrophthalazine-6-onitrile (61)

[0737] 6-Bromo-4-(2-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)propyl-2-yl)phthalazine-1(2H)-one (61-a, 76 mg, 0.137 mmol) was dissolved in N,N-dimethylformamide (5 mL), and zinc cyanide (32 mg, 0.273 mmol) and tetrakis(triphenylphosphine)palladium (32 mg, 27.3 μmol) were added. The reaction was carried out overnight at 110 °C under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 1-oxo-4-(2-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)propyl-2-yl)-1,2-dihydrophthalazine-6-onitrile (61 mg, 16.72 mg, yield 22.6%). ESI [M+H] + =541.2 1 H NMR (600MHz, DMSO-d6) δ12.86(s,1H),9.75(s,1H),8.71(s,2H),8.38(d,J=8.2Hz,1H),8.18(d,J=8.2Hz,1H),3.84–3.69(m,4H),3.59–3 .37(m,4H),3.05(t,J=9.5Hz,1H),2.95–2.86(m,1H),2.86–2.78(m,1H),2.19(dd,J=22.8,15.1Hz,2H),2.07–1.97(m,2H),1.45(s,6H).

[0738] Example 62: Preparation of 1-oxo-4-(1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)ethyl)-1,2-dihydrophthalazine-6-onitrile (62)

[0739]

[0740] Step 1: Preparation of 6-bromo-4-(1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)ethyl)phthalazine-1(2H)-one (62-a)

[0741] 6-Bromo-4-(1-Bromomethyl)phthalazin-1(2H)-one (I-24, 100 mg, 0.301 mmol) was dissolved in dichloromethane (4 mL), and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 99 mg, 0.301 mmol) and triethylamine (50 μL, 0.362 mmol) were added. The mixture was stirred at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 6-bromo-4-(1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)ethyl)phthalazine-1(2H)-one (62-a, 100 mg, yield 57.2%). ESI [M+H] + =580.4,582.4

[0742] Step 2: Preparation of 1-oxo-4-(1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)ethyl)-1,2-dihydrophthalazine-6-onitrile (62)

[0743] 6-Bromo-4-(1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)ethyl)phthalazine-1(2H)-one (62-a, 85 mg, 0.146 mmol) was dissolved in N,N-dimethylformamide (5 mL), and zinc cyanide (34 mg, 0.289 mmol) and tetrakis(triphenylphosphine)palladium (34 mg, 0.0294 mmol) were added. The reaction was carried out overnight at 110 °C under nitrogen protection. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (dichloromethane:methanol = 20:1) to give the target product 1-oxo-4-(1-(((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)amino)ethyl)-1,2-dihydrophthalazine-6-onitrile (62 mg, 15.09 mg, yield 19.57%). ESI [M+H] + =527.4 1 H NMR (600MHz, DMSO-d6) δ12.98(s,1H),8.86(s,1H),8.72(s,2H),8.40(d,J=8.1Hz,1H),8. 25(s,1H),3.80(s,5H),3.54(s,3H),3.38(s,3H),3.25(s,2H),2.33(s,3H),1.44(s,3H).

[0744] Example 63: Preparation of 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (63)

[0745]

[0746] 1-O-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazin-6-onitrile (12, 6.0 mg, 0.012 mmol) was dissolved in ethanol (1.8 mL), and water (0.6 mL), potassium carbonate (5 mg, 0.0316 mmol), and 30% hydrogen peroxide solution (35 μL) were added. The mixture was reacted overnight at room temperature. The reaction solution was filtered and purified using [Pack Column 30 ID * 250 mm * 10 μm; A: H₂O (0.1% FA), B: ACN, B%: 10%-40% over 30 min] to obtain the target product 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (63, 0.53 mg, yield 8.6%). ESI [M+H] + =517.2 1 H NMR (600MHz, DMSO-d6) δ12.68(s,1H),8.72(s,1H),8.53(s,1H),8.37(d,J=8.3Hz,2H),8.25(dd,J=26.8,8.3 Hz,2H),7.77(s,1H),3.87–3.75(m,4H),3.54(dd,J=12.8,6.4Hz,4H),3.52–3.45(m,4H),3.31–3.24(m,3H).

[0747] Example 64: Preparation of 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)methyl)-1,2-dihydrophthalazine-6-onitrile (64)

[0748]

[0749] Step 1: Preparation of 3,5-dibromoisobenzofuran-1(3H)-one (64-a)

[0750] 5-Bromoisobenzofuran-1(3H)-one (2 g, 9.39 mmol) was dissolved in ethyl acetate (40 mL), and N-bromosuccinimide (2.5 g, 14.08 mmol) and benzoyl peroxide (0.22 g, 0.939 mmol) were added. The mixture was stirred at 80 °C for 4 hours. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (30 g silica gel column, petroleum ether: ethyl acetate = 5:1) to obtain the target product 3,5-dibromoisobenzofuran-1(3H)-one (64-a, 690 mg, yield 25.18%).

[0751] Step 2: Preparation of 5-bromo-3-hydroxyisobenzofuran-1(3H)-one (64-b)

[0752] 3,5-Dibromoisobenzofuran-1(3H)-one (64-a, 690 mg, 2.36 mmol) was dissolved in water (10 mL), and potassium hydroxide (398 mg, 7.08 mmol) was added. The mixture was stirred at 80 °C for 3 hours. After cooling, the pH of the reaction solution was adjusted to 5-6 with 1 M hydrochloric acid solution in an ice bath. The mixture was stirred until a white solid completely precipitated. The solution was filtered, the filter cake was rinsed with water, and the filter cake was dried to obtain the target product 5-bromo-3-hydroxyisobenzofuran-1(3H)-one (64-b, 540 mg, yield 99.75%).

[0753] Step 3: Preparation of dimethyl (6-bromo-3-oxo-1,3-dihydroisobenzofuran-1-yl)phosphonate (64-c)

[0754] 5-Bromo-3-hydroxyisobenzofuran-1(3H)-one (64-b, 540 mg, 2.36 mmol) was dissolved in dimethyl phosphite (6 mL) and stirred at 100 °C for 2 hours under nitrogen protection. The reaction mixture was cooled and quenched with water, extracted with ethyl acetate, and the combined organic phases were washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by Flash column chromatography (10 g silica gel column, petroleum ether:ethyl acetate = 1:1) to obtain the target product (6-bromo-3-oxo-1,3-dihydroisobenzofuran-1-yl)phosphonate dimethyl ester (64-c, 374 mg, yield 49.41%). ESI [M+H] + =321.2,323.2

[0755] Step 4: Preparation of methyl 3-formylcyclobutane-1-carboxylate (64-d)

[0756] Methyl 3-(hydroxymethyl)cyclobutane-1-carboxylate (500 mg, 3.47 mmol) was dissolved in dichloromethane (30 mL), and Dys-Martin oxidant (2 g, 4.86 mmol) was added under ice bath conditions. The mixture was stirred overnight at room temperature. After filtration, the reaction solution was rinsed with dichloromethane. The filtrate was washed with sodium thiosulfate solution, then with saturated sodium bicarbonate solution, and finally with brine. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the target product, methyl 3-(hydroxymethyl)cyclobutane-1-carboxylate (64-d, 650 mg, crude product).

[0757] Step 5: Preparation of methyl 3-((6-bromo-3-oxoisobenzofuran-1(3H)-ylidene)methyl)cyclobutane-1-carboxylate (64-e)

[0758] Dimethyl (6-bromo-3-oxo-1,3-dihydroisobenzofuran-1-yl)phosphonate (64-c, 228 mg, 0.708 mmol) was dissolved in tetrahydrofuran (6 mL), and methyl 3-(hydroxymethyl)cyclobutane-1-carboxylate (64-d, 151 mg, 1.06 mmol) and potassium carbonate (294 mg, 2.12 mmol) were added. The mixture was stirred at 60 °C for 3 hours. The reaction solution was filtered and concentrated under reduced pressure. The crude product was purified by Flash column chromatography (10 g silica gel column, petroleum ether: ethyl acetate = 3:1) to obtain the target product methyl 3-((6-bromo-3-oxoisobenzofuran-1(3H)-ylidene)methyl)cyclobutane-1-carboxylate (64-e, 106 mg, yield 44.35%). ESI [M+H] + =337.0,339.0

[0759] Step 6: Preparation of methyl 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)cyclobutane-1-carboxylate (64-f)

[0760] Methyl 3-((6-bromo-3-oxoisobenzofuran-1(3H)-ylidene)methyl)cyclobutane-1-carboxylate (64-e, 106 mg, 0.314 mmol) was dissolved in tetrahydrofuran (2 mL), and hydrazine hydrate (31 μL, 0.629 mmol) was added. The mixture was stirred at 70 °C for 3 hours. The reaction solution was concentrated under reduced pressure to obtain the target product, methyl 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)cyclobutane-1-carboxylate (64-f, 117 mg, yield 106.36%). ESI[M+H] + =351.1,353.3

[0761] Step 7: Preparation of 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)cyclobutane-1-carboxylic acid (64 g)

[0762] Methyl 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)cyclobutane-1-carboxylic acid (64-g, 117 mg, 0.333 mmol) was dissolved in tetrahydrofuran (2 mL) and water (1 mL), and lithium hydroxide monohydrate (28 mg, 0.666 mmol) was added. The mixture was stirred at room temperature for 2 hours. The pH of the reaction solution was adjusted to 5-6 with 1M hydrochloric acid solution in an ice bath, and the mixture was stirred until a white solid completely precipitated. The mixture was filtered, the filter cake was rinsed with water, and the filter cake was dried to obtain the target product 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)cyclobutane-1-carboxylic acid (64-g, 83 mg, yield 74.11%). ESI[M+H] + =337.1,339.0

[0763] Step 8: Preparation of 6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)methyl)phthalazine-1(2H)-one (64-h)

[0764] 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)cyclobutane-1-carboxylic acid (64 g, 41.5 mg, 0.123 mmol) was dissolved in dichloromethane (3 mL), followed by the addition of 2-(piperazin-1-yl)-5-(trifluoromethyl)pyrimidine hydrochloride (I-6, 40 mg, 0.148 mmol) and N,N-diisopropylethylamine (64 μL, 0.369 mmol). Finally, N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (47 mg, 0.123 mmol) was added, and the mixture was stirred at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (10 g silica gel column, dichloromethane:methanol = 10:1) to obtain the target product 6-bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)methyl)phthalazine-1(2H)-one (64-h, 91 mg, yield 134.22%). ESI [M+H + =551.3,553.2

[0765] Step 9: Preparation of 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)methyl)-1,2-dihydrophthalazine-6-onitrile (64)

[0766] 6-Bromo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)methyl)phthalazine-1(2H)-one (64-h, 45 mg, 0.0816 mmol) was dissolved in N,N-dimethylformamide (1 mL), and zinc cyanide (19 mg, 0.163 mmol) and tetrakis(triphenylphosphine)palladium (9 mg, 8.16 μmol) were added. The mixture was then reacted in a microwave oven at 120 °C for 1 hour under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 20ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 60min] to obtain the target product 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)methyl)-1,2-dihydrophthalazine-6-onitrile (64, 4.51 mg, yield 11.11%). ESI [M+H] + =498.40 1 H NMR(600MHz,DMSO-d6)δ12.79(d,J=2.8Hz,1H),8.72(s,2H),8.63(d,J=4.6Hz,1H),8.3 7(d,J=8.1Hz,1H),8.22(d,J=8.1Hz,1H),3.80(q,J=5.1Hz,4H),3.57–3.52(m,2H),3.4 7(d,J=14.9Hz,1H),3.44(t,J=5.4Hz,2H),3.17(d,J=7.7Hz,1H),3.02(d,J=7.4Hz,1H) ,2.69–2.65(m,1H),2.34(dd,J=17.7,9.0Hz,1H),2.28–2.22(m,1H),2.03–1.91(m,2H).

[0767] Example 65: Preparation of 1-oxo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)-1,2-dihydrophthalazine-6-onitrile (65)

[0768]

[0769] Step 1: Preparation of 6-bromo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)phthalazine-1(2H)-one (65-a)

[0770] 7-Bromo-4-oxo-3,4-dihydrophthalazin-1-carboxylic acid (I-26, 38 mg, 0.141 mmol) and aziridine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 53 mg, 0.169 mmol) were dissolved in N,N-dimethylformamide (2 mL), N,N-diisopropylethylamine (74 μL, 0.423 mmol) was added, and finally N,N,N′,N′-tetramethyl-O-(7-azirbenzotriazol-1-yl)hexafluorophosphate urea (54 mg, 0.141 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was concentrated under reduced pressure and then purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 6-bromo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)phthalazine-1(2H)-one (65-a, 48 mg, yield 60%). ESI [M+H] + =566.2,568.2

[0771] Step 2: Preparation of 1-oxo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)-1,2-dihydrophthalazine-6-onitrile (65)

[0772] 6-Bromo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carbonyl)phthalazin-1(2H)-one (65-a, 48 mg, 0.0848 mmol) was dissolved in N,N-dimethylformamide (3 mL), and zinc cyanide (20 mg, 0.17 mmol) and tetrakis(triphenylphosphine)palladium (10 mg, 8.48 μmol) were added. The mixture was then microwaved at 120 °C for 1 hour under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 60min] to obtain the target product 1-oxo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)-1,2-dihydrophthalazine-6-onitrile (65, 33 mg, yield 75.98%). ESI [M+H] + =513.3 1H NMR (600MHz, DMSO-d6) δ13.27(s,1H),8.88(d,J=1.3Hz,1H),8.74(s,2H),8.39(d,J=8.2Hz,1H),8.25(dd,J=8.2,1.5Hz,1H),4 .55–4.50(m,2H),4.35(t,J=9.6Hz,1H),4.24(dd,J=9.9,6.2Hz,1H),3.88–3.81(m,5H),3.65–3.55(m,2H),3.43–3.40(m,2H).

[0773] Example 66: Preparation of 7-cyano-4-oxo-N-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (66)

[0774]

[0775] Step 1: Preparation of 7-bromo-4-oxo-N-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (66-a)

[0776] 7-Bromo-4-oxo-3,4-dihydrophthalazin-1-carboxylic acid (I-26, 40 mg, 0.149 mmol) and ((1R,3R)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-7, 54 mg, 0.164 mmol) were dissolved in N,N-dimethylformamide (2 mL), N,N-diisopropylethylamine (78 μL, 0.447 mmol) was added, and finally N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (57 mg, 0.149 mmol) was added. The mixture was reacted at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 7-bromo-4-oxo-N-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (66-a, 50 mg, yield 58.64%). ESI [M+H] + =580.2,582.2

[0777] Step 2: Preparation of 7-cyano-4-oxo-N-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (66)

[0778] 7-Bromo-4-oxo-N-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (66-a, 50 mg, 0.0862 mmol) was dissolved in N,N-dimethylformamide (3 mL), and zinc cyanide (20 mg, 0.172 mmol) and tetrakis(triphenylphosphine)palladium (10 mg, 8.62 μmol) were added. The mixture was then microwaved at 120 °C for 1 hour under nitrogen protection. The reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 60min] to obtain the target product 7-cyano-4-oxo-N-((1R,3R)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (66, 15 mg, yield 33.07%). ESI [M+H] + =527.3

[0779] Example 67: Preparation of 4-(((2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)amino)methyl)pyrido[3,4-d]pyridazin-1(2H)-one (67)

[0780]

[0781] 2-Amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl-1-one (I-37, 60 mg, 0.207 mmol) was dissolved in dichloromethane (4 mL), and 4-(bromomethyl)pyrido[3,4-d]pyridazin-1(2H)-one (I-12, 50 mg, 0.209 mmol) and triethylamine (35 μL, 0.252 mmol) were added. The mixture was reacted at room temperature for 2 hours. The reaction solution was concentrated under reduced pressure. The crude product was purified by high-performance liquid chromatography (HPLC) [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 1-oxo-4-(1-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)ethyl)-1,2-dihydrophthalazine-6-onitrile (67, 0.63 mg, yield 0.67%). ESI [M+H] + =449.3 1H NMR (600MHz, DMSO-d6) δ12.83(s,1H),9.64(s,1H),8.95(d,J=5.2Hz,1H),8.73(s,1H),8.31( s,1H),8.06(d,J=5.2Hz,1H),4.07(s,2H),3.84–3.79(m,5H),3.57–3.54(m,3H),3.51(s,3H).

[0782] Example 68: Preparation of 7-cyano-4-oxo-N-(2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)-3,4-dihydrophthalazin-1-carboxamide (68)

[0783]

[0784] Step 1: Preparation of 7-bromo-4-oxo-N-(2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)-3,4-dihydrophthalazin-1-carboxamide (68-a)

[0785] 7-Bromo-4-oxo-3,4-dihydrophthalazin-1-carboxylic acid (I-26, 40 mg, 0.15 mmol) was dissolved in N,N-dimethylformamide (4 mL), and 2-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl-1-one (I-37, 52 mg, 0.18 mmol), N,N-diisopropylethylamine (78 μL, 0.45 mmol) and N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (68 mg, 0.18 mmol) were added. The mixture was reacted overnight at room temperature. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-4-oxo-N-(2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)-3,4-dihydrophthalazin-1-carboxamide (68-a, 60 mg, yield 74%). ESI [M+H] + =540.2,542.2

[0786] Step 2: Preparation of 7-cyano-4-oxo-N-(2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)-3,4-dihydrophthalazin-1-carboxamide (68)

[0787] 7-Bromo-4-oxo-N-(2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)-3,4-dihydrophthalazin-1-carboxamide (68-a, 60 mg, 0.111 mmol) was dissolved in N,N-dimethylformamide (5 mL), and zinc cyanide (39 mg, 0.233 mmol) and tetrakis(triphenylphosphine)palladium (13 mg, 0.01 mmol) were added. The mixture was then microwaved at 120 °C for 1 hour under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1). Triphenylphosphine oxide residue remained. The solution was then slurried with methanol to obtain the target product, 7-cyano-4-oxo-N-(2-oxo-2-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)ethyl)-3,4-dihydrophthalazin-1-carboxamide (68 mg, 5.44 mg, yield 10.2%). (ESI [M+H]) + =487.2 1 H NMR(600MHz,DMSO-d6)δ13.38(s,1H),9.21(s,1H),8.75(s,2H),8.69(s,1H),8.41(d,J =7.9Hz,1H),8.27(d,J=7.7Hz,1H),4.26(s,2H),3.93(s,2H),3.87(s,2H),3.63(s,4H).

[0788] Example 69: Preparation of 7-cyano-4-oxo-N-(3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)-3,4-dihydrophthalazin-1-carboxamide (69)

[0789]

[0790] Step 1: Preparation of 7-bromo-4-oxo-N-(3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)-3,4-dihydrophthalazin-1-carboxamide (69-a)

[0791] 7-Bromo-4-oxo-3,4-dihydrophthalazin-1-carboxylic acid (I-26, 45 mg, 0.17 mmol) was dissolved in N,N-dimethylformamide (4 mL), and 3-amino-1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)prop-1-one (I-42, 61 mg, 0.20 mmol), N,N-diisopropylethylamine (89 μL, 0.51 mmol) and N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (96 mg, 0.18 mmol) were added. The mixture was reacted overnight at room temperature. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-4-oxo-N-(3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)-3,4-dihydrophthalazin-1-carboxamide (69-a, 60 mg, crude product). ESI [M+H] + =554.2,556.2

[0792] Step 2: Preparation of 7-cyano-4-oxo-N-(3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)-3,4-dihydrophthalazin-1-carboxamide (69)

[0793] 7-Bromo-4-oxo-N-(3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)-3,4-dihydrophthalazin-1-carboxamide (69-a, 60 mg, 0.108 mmol) was dissolved in N,N-dimethylformamide (5 mL), and zinc cyanide (38 mg, 0.325 mmol) and tetrakis(triphenylphosphine)palladium (13 mg, 0.01 mmol) were added. The mixture was then microwaved at 120 °C for 1 hour under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1). Triphenylphosphine oxide residue remained. The solution was then slurried with methanol to obtain the target product, 7-cyano-4-oxo-N-(3-oxo-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)propyl)-3,4-dihydrophthalazin-1-carboxamide (69g, 1.56mg, yield 2.89%). (ESI [M+H]) + =501.3 1H NMR (600MHz, DMSO-d6) δ13.33(s,1H),9.18(s,1H),8.74(s,2H),8.65(t,J=5.8Hz,1H),8.39(d,J=8.2Hz,1H),8.26(d,J =8.2Hz,1H),3.88(d,J=5.0Hz,2H),3.85–3.81(m,2H),3.59(d,J=4.4Hz,4H),3.56–3.52(m,2H),2.70(t,J=6.8Hz,2H).

[0794] Example 70: Preparation of N-methyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (70)

[0795]

[0796] Step 1: Preparation of methyl 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-a)

[0797] Methyl 4-(bromomethyl)-1-oxo-1,2-dihydrophthalazine-6-carboxylate (I-32, 100 mg, 50% purity, 0.338 mmol) was dissolved in dichloromethane (10 mL), and aziridine-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-8, 106 mg, 0.338 mmol) was added. The reaction was carried out at room temperature for 2 hours. After the reaction solution was concentrated under reduced pressure, the crude product was purified by Flash (dichloromethane:methanol = 10:1) to obtain the target product methyl 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)aziridine-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylate (70-a, 23 mg, yield 25.5%). ESI [M+H] + =532.2

[0798] Step 2: Preparation of 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b)

[0799] Methyl 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-a, 23 mg, 77.7 μmol) was dissolved in tetrahydrofuran (3 mL), and water (1 mL) and lithium hydroxide hydrate (10 mg, 0.358 mmol) were added. The mixture was reacted at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure to remove tetrahydrofuran. Water (3 mL) was added, and the pH was adjusted to 3 with 1 M hydrochloric acid aqueous solution under ice bath conditions. A white solid precipitated. The mixture was filtered, and the filter cake was collected. The filter cake was concentrated under reduced pressure and dried to obtain the target product 1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b, 12 mg, yield 30.0%). ESI[M+H] + =518.2

[0800] Step 3: Preparation of N-methyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (70)

[0801] 1-O-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b, 12 mg, 23.2 μmol) was dissolved in dichloromethane (2 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (9.7 mg, 25.5 μmol) and N,N-diisopropylethylamine (12 μL, 69.6 μol) were added. After stirring in an ice bath for 20 minutes, methylamine hydrochloride (2.4 mg, 34.8 μmol) was added. After reacting at room temperature for 3 hours, the mixture was concentrated under reduced pressure. The crude product was then subjected to high-performance liquid chromatography (HPLC) [Pack]. Column 30ID*250mm*10μm; A:H2O(0.05% NH4HCO3), B:ACN, B%: 10%-45% over 35min] Preparation and purification yielded the target product N-methyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (70, 1.42 mg, yield 11.5%). ESI[M+H] + =531.2

[0802] 1H NMR (600MHz, DMSO-d6) δ12.67(s,1H),8.84(s,1H),8.73(d,J=7.2Hz,2H),8.48(s,1H),8.28(s,1H),8.20(dd, J=11.3,7.0Hz,1H),3.81(d,J=18.2Hz,6H),3.50(dd,J=24.4,13.3Hz,6H),3.29(d,J=3.4Hz,3H),2.85(s,3H).

[0803] Example 71: Preparation of 7-cyano-4-oxo-N-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (71)

[0804]

[0805] Step 1: Preparation of 7-bromo-4-oxo-N-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (71-a)

[0806] 7-Bromo-4-oxo-3,4-dihydrophthalazin-1-carboxylic acid (I-26, 50 mg, 0.186 mmol) was dissolved in N,N-dimethylformamide (4 mL), and ((1S,3S)-3-aminocyclobutyl)(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl)methyl ketone (I-9, 73 mg, 0.223 mmol), N,N-diisopropylethylamine (48 μL, 0.279 mmol) and N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)hexafluorophosphate urea (106 mg, 0.279 mmol) were added. The mixture was reacted overnight at room temperature. After the reaction was complete, the reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product 7-bromo-4-oxo-N-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (71-a, 50 mg, yield 46.4%). ESI [M+H] + =580.2,582.2

[0807] Step 2: Preparation of 7-cyano-4-oxo-N-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (71)

[0808] 7-Bromo-4-oxo-N-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (71-a, 45 mg, 0.078 mmol) was dissolved in N,N-dimethylformamide (5 mL), and zinc cyanide (27 mg, 0.233 mmol) and tetrakis(triphenylphosphine)palladium (9 mg, 0.008 mmol) were added. The mixture was then microwaved at 120 °C for 1 hour under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (dichloromethane:methanol = 10:1) to give the target product 7-cyano-4-oxo-N-((1S,3S)-3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)cyclobutyl)-3,4-dihydrophthalazine-1-carboxamide (71 mg, 11.93 mg, yield 29%). ESI [M+H] + =527.2 1 H NMR (600MHz, DMSO-d6) δ13.31(s,1H),9.02(d,J=7.7Hz,1H),8.97(s,1H),8.72(s,2H),8.38(d,J=8.2Hz,1H),8.24(d,J=8.2Hz,1H ),4.45–4.35(m,1H),3.86–3.77(m,4H),3.60–3.47(m,4H),3.19–3.09(m,1H),2.48(dd,J=8.0,1.9Hz,2H),2.32(q,J=9.9Hz,2H).

[0809] Example 72: Preparation of 6-(methanesulfonyl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (72)

[0810]

[0811] Step 1: Preparation of 2-iodo-4-(methylsulfonyl)benzoic acid (72-a)

[0812] 2-Amino-4-(methanesulfonyl)benzoic acid (900 mg, 4.19 mmol) was dissolved in acetonitrile (10 mL) and water (10 mL), then concentrated hydrochloric acid (3.5 mL, 41.9 mmol) was added. Sodium nitrite (433 mg, 6.28 mmol) was added under a nitrogen atmosphere at 0 °C, and the reaction was carried out at this temperature for 0.5 h. Then potassium iodide (1.04 g, 6.28 mmol) was added, and the reaction was carried out at room temperature for 1.5 h. After the reaction was complete, the reaction solution was diluted with water, extracted with ethyl acetate, the organic phase was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain a crude product. The crude product was purified by Flash column chromatography (dichloromethane:methanol = 10:1) to obtain the target product, 2-iodo-4-(methanesulfonyl)benzoic acid (72-a, 1.2 g, crude product).

[0813] Step 2: Preparation of methyl 2-iodo-4-(methylsulfonyl)benzoate (72-b)

[0814] 2-Iodo-4-(methanesulfonyl)benzoic acid (72-a, 1.2 g, 3.68 mmol) was dissolved in N,N-dimethylformamide (10 mL), and iodomethane (460 μL, 11.04 mmol) and potassium carbonate (1.5 g, 11.04 μmol) were added. The reaction was carried out at room temperature for 5 hours. After the reaction was completed, the reaction solution was concentrated and purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain the target product, methyl 2-iodo-4-(methanesulfonyl)benzoate (72-b, 700 mg, yield 55.9%). ESI [M+H] + =341.2

[0815] Step 3: Preparation of methyl 2-acetyl-4-(methylsulfonyl)benzoate (72-c)

[0816] Methyl 2-iodo-4-(methanesulfonyl)benzoate (72-b, 700 mg, 2.06 mmol) was dissolved in dioxane (10 mL), and tributyl(1-ethoxyvinyl)stanane (1.5 mL, 3.09 mmol) and palladium dichloro[1,1'-bis(diphenylphosphine)ferrocene]ide (151 mg, 0.206 mmol) were added. The reaction was carried out at 105 °C for 16 hours. After the reaction was completed, the reaction solution was concentrated, quenched with 1 M hydrochloric acid solution, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered and concentrated to obtain the crude product. The crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:2) to obtain the target product, methyl 2-acetyl-4-(methanesulfonyl)benzoate (72-c, 350 mg, crude product). ESI[M+H] + =285.3

[0817] Step 4: Preparation of 4-methyl-6-(methanesulfonyl)phthalazine-1(2H)-one (72-d)

[0818] Methyl 2-acetyl-4-(methanesulfonyl)benzoate (72-c, 350 mg, 1.37 mmol) was dissolved in ethanol (10 mL), and hydrazine hydrate (82 μL, 1.64 mmol) was added. The reaction was carried out at 70 °C for 3 hours. After the reaction was complete, the reaction solution was filtered to obtain the target product, 4-methyl-6-(methanesulfonyl)phthalazine-1(2H)-one (72-d, 180 mg, yield 55.2%). ESI[M+H] + =239.3

[0819] Step 5: Preparation of 4-(bromomethyl)-6-(methanesulfonyl)phthalazine-1(2H)-one (72-e)

[0820] 4-Methyl-6-(methanesulfonyl)phthalazin-1(2H)-one (72-d, 20 mg, 0.084 mmol) was dissolved in acetonitrile (4 mL), and N-bromosuccinimide (30 mg, 0.168 mmol) and azobisisobutyronitrile (14 mg, 0.084 mmol) were added. The mixture was then microwaved at 100 °C for 2 hours. After the reaction was complete, the reaction solution was concentrated and used directly in the next step to obtain the target product 4-(bromomethyl)-6-(methanesulfonyl)phthalazin-1(2H)-one (72-e, 30 mg, crude product). ESI[M+H] + =317.2,319.2

[0821] Step 6: Preparation of 6-(methanesulfonyl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (72)

[0822] 4-(bromomethyl)-6-(methanesulfonyl)phthalazin-1(2H)-one (72-e, 30 mg, 0.094 mmol) was dissolved in N,N-dimethylformamide (4 mL), and then azirmonobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 20 mg, 0.063 mmol) and triethylamine (10 μL, 0.076 mmol) were added. The mixture was reacted at room temperature for 1 hour. After the reaction was complete, the product 6-(methanesulfonyl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)phthalazine-1(2H)-one (72 mg, yield 3.2%) was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O(0.1%FA), B:ACN, B%: 10%-70% over 36 min] to obtain the target product. + =552.2 1 H NMR (600MHz, DMSO-d6) δ13.22(s,1H),10.70(s,1H),8.75(s,1H),8.52(d,J=8.1Hz,1H),8.48–8.33(m,2 H),5.01(d,J=56.8Hz,2H),4.43(d,J=76.9Hz,4H),4.14(s,2H),3.85(s,3H),3.61(s,2H),3.40(s,5H).

[0823] Example 73: Preparation of N-methoxy-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (73)

[0824]

[0825] 1-O-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b, 10 mg, 19.3 μmol) was dissolved in dichloromethane (2 mL), and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (8.1 mg, 21.3 μmol) and N,N-diisopropylethylamine (10 μL, 58.0 μmol) were added. After stirring in an ice bath for 20 minutes, O-methylhydroxylamine hydrochloride (2.4 mg, 29.0 μmol) was added. After reacting at room temperature for 3 hours, the reaction solution was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to high-performance liquid chromatography [Pack] Column 30ID*250mm*10μm; A:H2O(0.05% NH4HCO3), B:ACN, B%: 10%-45% over 35min] Preparation and purification yielded the target product N-methoxy-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (73, 0.51 mg, yield 4.84%). ESI[M+H] + =547.2 1 H NMR (600MHz, DMSO-d6) δ12.70(s,1H),8.72(s,2H),8.43(s,1H),8.29(d,J=8.0Hz,1H),8.12(d,J=8.2Hz,1 H),3.86–3.79(m,3H),3.77(s,3H),3.55(dd,J=17.2,6.2Hz,4H),3.49(d,J=7.5Hz,4H),3.33–3.22(m,4H).

[0826] Example 74: Preparation of N-ethoxy-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (74)

[0827]

[0828] 1-O-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b, 10 mg, 19.3 μmol) was dissolved in dichloromethane (2 mL), followed by the addition of 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate (8.1 mg, 21.3 μmol) and N,N-diisopropylethylamine (10 μL, 58.0 μmol). After stirring in an ice bath for 20 minutes, O-ethylhydroxylamine hydrochloride (2.8 mg, 29.0 μmol) was added. The mixture was reacted at room temperature for 3 hours, then concentrated under reduced pressure. The crude product was then processed by high performance liquid chromatography to prepare [Pack]. Column 30ID*250mm*10μm; A:H2O(0.05% NH4HCO3), B:ACN, B%: 10%-45% over 35min] Purification yielded the target product N-ethoxy-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (74, 1.12 mg, yield 6.88%). ESI[M+H] + =561.4 1 H NMR (600MHz, DMSO-d6) δ12.68(s,1H),12.02(s,1H),8.72(s,2H),8.43(s,1H),8.29(d,J=8.2Hz,1H),8.12(d,J=8.2Hz,1H),4.00(d,J= 6.5Hz,2H),3.83(s,2H),3.82–3.70(m,4H),3.55(t,J=10.9Hz,4H),3.50(t,J=7.1Hz,2H),3.29(t,J=6.8Hz,3H),1.25(t,J=6.8Hz,3H).

[0829] Example 75: Preparation of N-cyclobutyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (75)

[0830]

[0831] 1-O-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b, 15 mg, 29.0 μmol) was dissolved in dichloromethane (2 mL), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (8.3 mg, 34.5 μmol), 1-hydroxybenzotriazole (4.7 mg, 34.5 μmol), N,N-diisopropylethylamine (15 μL, 87.0 μmol), and cyclobutamine (5 μL, 58.0 μmol) were added. After reacting at room temperature for 3 hours, the mixture was concentrated under reduced pressure. The crude product was then analyzed by high-performance liquid chromatography [Pack]. Column 30ID*250mm*10μm; A:H2O(0.05% NH4HCO3), B:ACN, B%: 10%-100% over 50min] Preparation and purification yielded the target product N-cyclobutyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (75, 2.63 mg, yield 20.97%). ESI[M+H] + =571.3 1 H NMR(600MHz,DMSO-d6)δ12.66(s,1H),8.97(d,J=7.3Hz,1H),8.72(s,2H),8.45(s,1H),8 .28(d,J=8.2Hz,1H),8.21(d,J=8.2Hz,1H),4.46(td,J=16.2,8.1Hz,1H),3.85(s,2H),3 .83–3.74(m,4H),3.62–3.52(m,4H),3.51–3.47(m,2H),3.30(d,J=5.6Hz,2H),2.89-2.7 3(d,1H),2.31–2.23(m,2H),2.10(dd,J=20.6,9.8Hz,2H),1.71(dd,J=18.9,7.5Hz,2H).

[0832] Example 76: Preparation of 4-(bromomethyl)-6-(trifluoromethyl)sulfonyl)phthalazine-1(2H)-one (76)

[0833]

[0834] Step 1: Preparation of 2-bromo-4-(trifluoromethyl)thio)benzaldehyde (76-a)

[0835] 4-(trifluoromethyl)thiobenzaldehyde (2 g, 9.7 mmol) and 4-chloro-2-(trifluoromethyl)aniline (379 mg, 1.94 mmol) were dissolved in 1,2-dichloroethane (40 mL) and trifluoroacetic acid (10 mL). N-bromosuccinimide (2.07 g, 11.64 mmol) and palladium acetate (220 mg, 0.971 mmol) were added, and the reaction was carried out overnight at 60 °C under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 9:1) to obtain the target product 2-bromo-4-(trifluoromethyl)thiobenzaldehyde (76-a, 1.1 g, yield 39.78%). ESI [M+H] + =285.0,287.0

[0836] Step 2: Preparation of 2-bromo-4-(trifluoromethyl)thiobenzoic acid (76-b)

[0837] 2-Bromo-4-(trifluoromethyl)thio)benzaldehyde (76-a, 1.1 g, 3.86 mmol) was dissolved in acetone (8 mL), and potassium permanganate (915 mg, 5.79 mmol) was added. The mixture was reacted overnight at room temperature. The reaction solution was concentrated under reduced pressure and then slurried with methanol to obtain the target product, 2-bromo-4-(trifluoromethyl)thio)benzoic acid (76-b, 800 mg, yield 68.86%). ESI[M+H] + =301.0,303.0

[0838] Step 3: Preparation of methyl 2-bromo-4-((trifluoromethyl)thio)benzoate (76-c)

[0839] 2-Bromo-4-(trifluoromethyl)thiobenzoic acid (76-b, 800 mg, 2.66 mmol) was dissolved in methanol (12 mL), and sulfuric acid (212 μL, 3.99 mmol) was added. The mixture was reacted overnight at 70 °C. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 9:1) to obtain the target product, methyl 2-bromo-4-((trifluoromethyl)thio)benzoate (76-c, 450 mg, yield 53.75%). ESI [M+H] + =315.2,316.9

[0840] Step 4: Preparation of methyl 2-bromo-4-((trifluoromethyl)sulfonyl)benzoate (76-d)

[0841] Methyl 2-bromo-4-((trifluoromethyl)thio)benzoate (76-c, 450 mg, 1.43 mmol) was dissolved in dichloromethane (15 mL), and m-chloroperoxybenzoic acid (986 mg, 5.71 mmol) was added under ice bath conditions. The mixture was heated to 40 °C and reacted for 48 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 6:1) to obtain the target product, methyl 2-bromo-4-((trifluoromethyl)sulfonyl)benzoate (76-d, 390 mg, yield 78.63%). ESI [M+H] + =347.1,349.1

[0842] Step 5: Preparation of methyl 2-acetyl-4-(trifluoromethyl)sulfonyl)benzoate (76-e)

[0843] Methyl 2-bromo-4-((trifluoromethyl)sulfonyl)benzoate (76-d, 390 mg, 1.12 mmol) was dissolved in 1,4-dioxane (10 mL), and tributyl(1-ethoxyethylene)tin (569 μL, 1.69 mmol) and 1,1-bis(diphenylphosphine)ferrocene palladium(II) chloride (82 mg, 0.112 mmol) were added. The mixture was reacted overnight at 105 °C under nitrogen protection. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 3:1) to obtain an intermediate compound. The organic phase was concentrated under reduced pressure, dissolved in tetrahydrofuran (10 mL), and 10% hydrochloric acid solution was added and stirred for 1 hour. The pH was then adjusted to 8 with saturated sodium bicarbonate solution. The mixture was extracted three times with ethyl acetate, dried over anhydrous sodium sulfate, and filtered to obtain the target product, methyl 2-acetyl-4-(trifluoromethyl)sulfonyl)benzoate (76-e, 300 mg, yield 86.06%). ESI[M+H] + =311.3

[0844] Step 6: Preparation of 4-methyl-6-((trifluoromethyl)sulfonyl)phthalazine-1(2H)-one (76-f)

[0845] Methyl 2-acetyl-4-(trifluoromethyl)sulfonyl)benzoate (76-e, 300 mg, 0.967 mmol) was dissolved in ethanol (8 mL), and hydrazine hydrate (145 μL, 2.9 mmol) was added. The reaction mixture was reacted at 70 °C for 2 hours. The reaction solution was concentrated under reduced pressure and then slurried with acetonitrile to obtain the target product, 4-methyl-6-((trifluoromethyl)sulfonyl)phthalazine-1(2H)-one (76-f, 100 mg, yield 35.39%). ESI[M+H] + =293.1

[0846] Step 7: Preparation of 4-(bromomethyl)-6-(trifluoromethyl)sulfonyl)phthalazine-1(2H)-one (76 g)

[0847] 4-Methyl-6-((trifluoromethyl)sulfonyl)phthalazine-1(2H)-one (76-f, 100 mg, 0.342 mmol) was dissolved in acetonitrile (5 mL), and N-bromosuccinimide (122 mg, 0.685 mmol) and azobisisobutyronitrile (56 mg, 0.341 mmol) were added. The reaction mixture was reacted at 120 °C for 48 hours. The reaction solution was concentrated under reduced pressure and purified by Flash column chromatography (petroleum ether: ethyl acetate = 2:1) to obtain the target product 4-(bromomethyl)-6-(trifluoromethyl)sulfonyl)phthalazine-1(2H)-one (76-g, 20 mg, yield 15.75%). ESI [M+H] + =371.1,373.0

[0848] Step 8: Preparation of 4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-6-((trifluoroformyl)sulfonyl)phthalazin-1(2H)-one (76)

[0849] 4-(bromomethyl)-6-(trifluoromethyl)sulfonyl)phthalazin-1(2H)-one (76 g, 20 mg, 0.0539 mmol) was dissolved in dichloromethane (25 mL), and 3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carboxylic acid tert-butyl ester (I-8, 17 mg, 0.054 mmol) and triethylamine (9 μL, 0.0642 mmol) were added. The mixture was reacted overnight at room temperature. After reaction filtration and concentration under reduced pressure, the crude product was purified by high-performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 5%-100% over 50min] to obtain the target product 4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-6-((trifluoroformyl)sulfonyl)phthalazin-1(2H)-one (76, 0.53 mg, yield 1.623%). ESI [M+H] + =606.4 1 H NMR (600MHz, DMSO-d6) δ13.02(s,1H),8.84(s,1H),8.72(d,J=10.9Hz,2H),8.60(d,J=8.3Hz,1H),8.45(d,J=8 .0Hz,1H),3.91(s,1H),3.82–3.76(m,2H),3.71(s,2H),3.53(d,J=4.7Hz,6H),3.30(s,2H),2.02–1.95(m,2H).

[0850] Example 77: Preparation of N-cyclopropyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (77)

[0851]

[0852] 1-O-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxylic acid (70-b, 15 mg, 29.0 μmol) was dissolved in dichloromethane (2 mL), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (8.3 mg, 34.5 μmol), 1-hydroxybenzotriazole (4.7 mg, 34.5 μmol), N,N-diisopropylethylamine (15 μL, 87.0 μmol), and cyclopropylamine (4 μL, 58.0 μmol) were added. After reacting at room temperature for 3 hours, the mixture was concentrated under reduced pressure. The crude product was then subjected to [Pack Column] [30ID*250mm*10μm; A:H2O(0.05%NH4HCO3), B:ACN, B%: 10%-100% over 50min] Purification yielded the target product N-cyclopropyl-1-oxo-4-((3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-yl)methyl)-1,2-dihydrophthalazine-6-carboxamide (77, 2.17 mg, yield 13.5%). ESI [M+H] + =557.4 1 H NMR (600MHz, DMSO-d6) δ12.64(s,1H),8.80(d,J=3.4Hz,1H),8.70(s,2H),8.42(s,1H),8.25(d,J=8.3Hz,1H),8.15(d,J=8.3Hz,1H),3.82(s, 2H),3.77(dd,J=11.8,6.5Hz,4H),3.63–3.43(m,6H),3.30–3.25(m,2H),2.90-2.86(m,2H),0.77–0.70(m,2H),0.60(dd,J=10.3,4.8Hz,2H).

[0853] Example 78: Preparation of 6-(prop-1-yn-1-yl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carbonyl)phthalazin-1(2H)-one (78)

[0854]

[0855] Step 1: Preparation of 6-bromo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)phthalazine-1(2H)-one (78-a)

[0856] Dissolve 7-bromo-4-oxo-3,4-dihydrophthalazin-1-carboxylic acid (I-26, 35 mg, 0.13 mmol) in N,N-dimethylformamide (4 mL), add O-(7-azabenzotriazol-1-yl)-N,N,N,N-tetramethyluronic acid hexafluorophosphate (50 mg, 0.13 mmol) and N,N-diisopropylethylamine (68 μL, 0.39 mmol), stir for 10 minutes, then add azacyclobutane-3-yl(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-yl) methyl ketone (I-8, 49.5 mg, 0.017 mmol), and react overnight at room temperature. After the reaction was completed, the reaction solution was concentrated under reduced pressure, and the crude product was purified by Flash column chromatography (petroleum ether: ethyl acetate = 1:2) to obtain the target product 6-bromo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-1-carbonyl)phthalazine-1(2H)-one (78-a, 68 mg, yield 91.89%). ESI [M+H] + =567.40

[0857] Step 2: Preparation of 6-(prop-1-yn-1-yl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carbonyl)phthalazin-1(2H)-one (78)

[0858] 6-Bromo-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carbonyl)phthalazin-1(2H)-one (78-a, 36 mg, 0.064 mmol) was dissolved in dioxane (2 mL), followed by the addition of tributylpropynyltinane (31.4 μL, 0.095 mmol), and then tetrakis(triphenylphosphine)palladium (7.4 mg, 0.064 mmol). After nitrogen purging, the mixture was reacted in a microwave oven at 110 °C for 1 hour. After the reaction was completed, the product was filtered, concentrated under reduced pressure, and then purified by high performance liquid chromatography [Pack Column 30ID*250mm*10μm; A:H2O (0.1% FA), B:ACN, B%: 10%-100% over 35min] to obtain the target product 6-(prop-1-yn-1-yl)-4-(3-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazin-1-carbonyl)azacyclobutane-1-carbonyl)phthalazin-1(2H)-one (78, 2.61 mg, yield 7.8%). ESI [M+H] +=526.30 1 HNMR (600MHz, DMSO-d6) δ13.00(s,1H),8.74(s,2H),8.37(s,1H),8.20(d,J=8.2Hz,1H),7.81(d,J=8.2Hz,1H),4.47(t,J=10.7Hz, 2H),4.32(t,J=9.5Hz,1H),4.25–4.21(m,1H),3.85(d,J=4.6Hz,5H),3.63–3.55(m,2H),3.41(dd,J=13.6,5.6Hz,2H),2.13(s,3H).

[0859] Example 79: Preparation of 1-oxo-4-((1-(4-(5-(trifluoromethyl)pyrimidin-2-yl)piperazine-1-carbonyl)azacyclobutane-3-yl)methyl)-1,2-dihydrophthalazine-6-onitrile (79)

[0860]

[0861] Step 1: Preparation of tert-butyl 3-((6-bromo-3-oxoisobenzofuran-1(3H)-ylidene)methyl)azacyclobutane-1-carboxylate (79-a)

[0862] 3-Formylaziridine-1-carboxylate tert-butyl ester (200 mg, 1.08 mmol) was dissolved in tetrahydrofuran (10 mL), and dimethyl (6-bromo-3-oxo-1,3-dihydroisobenzofuran-1-yl)phosphonate (64-c, 381 mg, 1.187 mmol) and potassium carbonate (448 mg, 3.24 mmol) were added. The mixture was stirred at 60 °C for 3 hours. The reaction solution was filtered and concentrated under reduced pressure to obtain the crude product 3-((6-bromo-3-oxoisobenzofuran-1(3H)-ylidene)methyl)aziridine-1-carboxylate tert-butyl ester (79-a, 400 mg, yield 97.42%). ESI [M+H-56] + =324.1,326.0

[0863] Step 2: Preparation of tert-butyl 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-1-carboxylate (79-b)

[0864] 3-((6-bromo-3-oxoisobenzofuran-1(3H)-ylidene)methyl)azacyclobutane-1-carboxylic acid tert-butyl ester (79-a, 400 mg, 1.05 mmol) was dissolved in tetrahydrofuran (5 mL), and hydrazine hydrate (132 mg, 2.63 mmol) was added. The mixture was stirred at 70 °C for 3 hours. The reaction solution was concentrated under reduced pressure to obtain the target product 3-((7-bromo-4-oxo-3,4-dihydrophthalazin-1-yl)methyl)azacyclobutane-1-carboxylic acid tert-butyl ester (79-b, 4...

Claims

1. A compound represented by Formula (I), a pharmaceutically acceptable salt, stereoisomer, solvate or prodrug thereof, In Formula (I), T1is selected from CH, CR6, or N; T2is selected from CH, CR6, or N; T6is selected from CH, CR6, or N; Y1is selected from -NH-C 3-7 cycloalkyl-, 3-10 membered nitrogen-containing heterocycloalkyl containing at least one nitrogen atom, 5-6 membered heterocycloaryl, 5-6 membered heterocycloalkyl, -NHCH2-, -NHCH2CH2-; T3is selected from CH, CR5, or N; T4is selected from CH, CR5, or N; T5is selected from CH, CR5, or N; n1 R5, equal to or different from each other, n1 being selected from 0, 1, 2 or 3, R5 being selected from hydrogen, deuterium, -CF3, -CN, -OCH3 or R6 is selected from hydrogen, deuterium, -CN, -F, -Br, -CF3, -OCF3, n2is selected from 0 or 1; T7is selected from a single bond, C, CH2, -O- or -OCH2-; preferably, T7is selected from C, R7is selected from hydrogen, deuterium, -CH3, -F, -CF3, R8is selected from hydrogen, deuterium, -CH3, -F, -CF3, or R7, R8and the common attached carbon atom form a carbonyl group.

2. The following compounds, pharmaceutically acceptable salts, stereoisomers, solvates, or prodrugs thereof, 3. A pharmaceutical composition comprising a compound according to any one of claims 1-2, a pharmaceutically acceptable salt, stereoisomer, solvate or prodrug thereof, and at least one pharmaceutically acceptable carrier.

4. Use of a compound according to any one of claims 1-2, or a pharmaceutically acceptable salt, stereoisomer, solvate or prodrug thereof, or a pharmaceutical composition of claim 3, for the manufacture of a PARP7 inhibitor or for the treatment of a disease mediated by PARP7; Preferably, the disease mediated by PARP7 comprises cancer, immune disease, inflammation and viral infection; Preferably, the cancer comprises a solid tumor with PARP7 amplification; Preferably, the solid tumor with PARP7 amplification comprises lung cancer, esophageal cancer and head and neck cancer.

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