Hydrazone-modified polycyclic hydroxypyridinone derivatives, methods of making and using the same

Abstract

The application belongs to the technical field of medicine synthesis, and provides a hydrazone-modified polycyclic hydroxypyridinone derivative, a preparation method and application thereof. The hydrazone-modified polycyclic hydroxypyridinone derivative provided by the application has the structure shown in the following formula. The hydrazone-modified polycyclic hydroxypyridinone derivative of the application can inhibit RNA-dependent RNA polymerase of influenza virus, has obvious inhibitory activity on replication of the influenza virus, and has good drug development prospects according to preliminary toxicity research; at the same time, has low cytotoxicity and good safety. The hydrazone-modified polycyclic hydroxypyridinone derivative of the application has the characteristics of novel structure, good antiviral activity and the like, and has good application prospects in the field of anti-influenza virus drug research and development. The results of the examples show that the EC 50 of the hydrazone-modified polycyclic hydroxypyridinone derivative against IAV is 0.44-1.57 nM.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical synthesis technology, and in particular to a class of hydrazone-modified polycyclic hydroxypyridinone derivatives, their preparation methods, and applications. Background Technology

[0002] Influenza viruses continue to pose a serious threat to global public health. Commonly used anti-influenza drugs in clinical practice include M2 ​​ion channel blockers (such as amantadine) and neuraminidase inhibitors (such as oseltamivir). However, the use of M2 ion channel blockers is limited due to widespread drug resistance; and the number of viral strains resistant to neuraminidase inhibitors is gradually increasing. The continuous emergence of drug-resistant strains highlights the urgency of developing novel anti-influenza drugs.

[0003] Influenza virus RNA-dependent RNA polymerase (RdRp) is highly conserved across different subtypes, making it a highly attractive drug target. RdRp consists of polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), and polymerase acidic protein (PA) subunits. The N-terminal domain of the PA subunit possesses cap-dependent endonuclease (CEN) activity, catalyzing the viral "cap-stripping" mechanism and providing primers for viral transcription. In 2018, the first CEN inhibitor, baloxavirmarboxil, was approved for marketing. This drug uses a polycyclic hydroxypyridinone backbone as a metal-binding pharmacophore (MBP), coordinating with a bimetallic ion at the PA active site, while simultaneously enhancing binding to the enzyme pocket through a hydrophobic binding group (HBG). Current medicinal chemistry research mainly focuses on HBG optimization (such as backbone transitions, the introduction of spirocyclic or macrocyclic structures), while research on the core MBP structure is relatively scarce. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a class of hydrazone-modified polycyclic hydroxypyridinone derivatives, their preparation methods, and applications. The hydrazone-modified polycyclic hydroxypyridinone derivatives provided by this invention can inhibit the RNA-dependent RNA polymerase (RdRp) of influenza virus, exhibiting significant inhibitory activity against influenza virus replication.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a class of hydrazone-modified polycyclic hydroxypyridinone derivatives having the structure shown in Formula I: Formula I; In Formula I, R1 and R2 are independently selected from H, C1~C6 alkyl, C3~C7 cycloalkyl, C1~C6 hydroxyalkyl, C1~C6 haloalkyl, C6~C10 aryl, C6~C10 arylalkyl or R4-C(O)-; Alternatively, R1 and R2 together with the nitrogen atoms they are attached to form 5-6 membered heterocyclic groups; R4 is selected from alkyl, substituted alkyl, alkynyl, substituted alkynyl, carbamoyl, heteroaryl, substituted heteroaryl, aryl, substituted aryl, alkoxy, or 9-fluorenoxycarbonyl.

[0006] Preferably, in R1 and R2, the number of carbon atoms in the C1-C6 alkyl group is 1-3; The C3-C7 cycloalkyl group has 4-6 carbon atoms; The C1-C6 hydroxyalkyl group has 1-3 carbon atoms; The C1-C6 haloalkyl group has 1-3 carbon atoms, and the halogen includes fluorine; The number of carbon atoms in the C6~C10 arylalkyl group is 1~3; In R4, the alkyl group has 1 to 6 carbon atoms; The substituted alkyl group is a cyano group; The number of carbon atoms in the alkynyl group is 1 to 6; The substituent in the substituted alkynyl group is a halogen; The heteroaryl group has 6 to 10 carbon atoms, and the heteroatom includes nitrogen atoms, with 1 to 2 nitrogen atoms. The substituents in the substituted heteroaryl group are halogens; The aryl group has 6 to 10 carbon atoms; The substituent in the substituted aryl group is a hydroxyl group; The number of carbon atoms in the alkoxy group is 1 to 6.

[0007] Preferably, in R1 and R2, the C1~C6 alkyl group is -CH3 or -CH2CH3; The C3-C7 cycloalkyl group is cyclobutyl, cyclopentyl, or cyclohexyl; The C1~C6 hydroxyalkyl group is -CH2CH2OH; The C1~C6 haloalkyl group is -CH2CF3; The C6-C10 aryl group is phenyl; The C6~C10 arylalkyl group is -CH2-Ph or -CH2-CH2-Ph; R1 and R2, together with the nitrogen atoms they are attached to, form 5-6 membered heterocyclic groups. or ; In R4, the alkyl group is -CH3, -CH2CH3, -CH2CH2CH3 or -CH2CH2CH2CH3; The substituted alkyl group is -CH2-C≡N; The heteroaryl group is , or ; The substituted heteroaryl group is ; The substituted aryl group is ; The alkoxy group is -OCH3, -OCH2CH3 or -OC(CH3)3.

[0008] Preferably, it has the following structure: , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0009] This invention also provides a method for preparing the hydrazone-modified polycyclic hydroxypyridinone derivatives described in the above technical solution, comprising the following steps: The first compound having the structure shown in Formula a was subjected to a methylation reaction with trimethyloxonium tetrafluoroborate to obtain the second compound having the structure shown in Formula b. Formula a; Formula b; The second compound is subjected to a substitution reaction with hydrazine or a substituted hydrazine to obtain the hydrazone-modified polycyclic hydroxypyridinone derivative having the structure shown in Formula I.

[0010] Preferably, the methylation reaction is carried out at room temperature for 3-5 hours. The substitution reaction is carried out at a temperature of 50-80°C for 2-8 hours.

[0011] The present invention also provides a prodrug of the hydrazone-modified polycyclic hydroxypyridinone derivative described in the above technical solution, wherein the structure of the prodrug is: the oxygen in the hydroxyl group on the pyridine ring of the structure shown in Formula I forms an ester group or an ether group with R3; R3 is selected from H, , ;R a and R b Independently selected from H, C1~C3 alkyl, aryl; m is 1 or 2.

[0012] The present invention also provides pharmaceutically acceptable salts of the hydrazone-modified polycyclic hydroxypyridinone derivatives described in the above-described technical solutions.

[0013] The present invention also provides the use of the hydrazone-modified polycyclic hydroxypyridinone derivatives, the prodrugs, or the pharmaceutically acceptable salts described above in the preparation of anti-influenza virus drugs.

[0014] Preferably, the influenza virus is an influenza A virus and / or an influenza B virus.

[0015] This invention provides a class of hydrazone-modified polycyclic hydroxypyridinone derivatives.

[0016] This invention proposes a bioisosteric substitution strategy targeting MBP: replacing the key ketone carbonyl group in MBP with a hydrazone to regulate the electronic properties and spatial orientation of ligand-metal interactions, aiming to discover novel compounds with highly efficient and broad-spectrum anti-influenza virus activity that can overcome drug-resistant mutants. The hydrazone-modified polycyclic hydroxypyridinone derivatives provided by this invention can inhibit influenza virus RNA-dependent RNA polymerase (RdRp), exhibiting significant inhibitory activity against influenza virus replication. Preliminary toxicity studies show good drug-likeness, indicating that this type of derivative has good application prospects as an antiviral drug; simultaneously, it exhibits low cytotoxicity and good safety. The hydrazone-modified polycyclic hydroxypyridinone derivatives of this invention possess novel structures and good antiviral activity, showing promising application prospects in the field of anti-influenza virus drug development. The results of the examples show that the hydrazone-modified polycyclic hydroxypyridinone derivatives provided by this invention have EC2 anti-IAV activity. 50 The range is 0.44~1.57 nM. Detailed Implementation

[0017] This invention provides a class of hydrazone-modified polycyclic hydroxypyridinone derivatives having the structure shown in Formula I: Formula I; In Formula I, R1 and R2 are independently selected from H, C1~C6 alkyl, C3~C7 cycloalkyl, C1~C6 hydroxyalkyl, C1~C6 haloalkyl, C6~C10 aryl, C6~C10 arylalkyl or R4-C(O)-; Alternatively, R1 and R2 together with the nitrogen atoms they are attached to form 5-6 membered heterocyclic groups; R4 is selected from alkyl, substituted alkyl, alkynyl, substituted alkynyl, carbamoyl (NH2-C(O)-), heteroaryl, substituted heteroaryl, aryl, substituted aryl, alkoxy, or 9-fluorenoxycarbonyl.

[0018] In this invention, the number of carbon atoms in the C1-C6 alkyl group of R1 and R2 is preferably 1 to 3, specifically 1, 2, 3, 4, 5, or 6. Specifically, the C1-C6 alkyl group is preferably -CH3 or -CH2CH3.

[0019] In this invention, in R1 and R2, the number of carbon atoms in the C3-C7 cycloalkyl group is preferably 4-6, specifically 3, 4, 5, 6, or 7. In this invention, the C3-C7 cycloalkyl group is specifically preferably cyclobutyl, cyclopentyl, or cyclohexyl.

[0020] In this invention, in R1 and R2, the number of carbon atoms in the C1-C6 hydroxyalkyl group is preferably 1-3, specifically 1, 2, 3, 4, 5, or 6. In this invention, the number of hydroxyl groups in the C1-C6 hydroxyalkyl group is preferably 1-3, specifically 1, 2, or 3. In this invention, the C1-C6 hydroxyalkyl group is preferably -CH2CH2OH.

[0021] In this invention, in R1 and R2, the number of carbon atoms in the C1-C6 haloalkyl group is preferably 1-3, specifically 1, 2, 3, 4, 5, or 6; the halogen preferably includes fluorine. In this invention, the number of halogens in the C1-C6 haloalkyl group is preferably 1-5, specifically 1, 2, 3, 4, or 5. In this invention, the C1-C6 haloalkyl group is specifically preferably -CH2CF3.

[0022] In this invention, the number of carbon atoms in the C6-C10 aryl group in R1 and R2 can specifically be 6, 7, 8, 9, or 10. In this invention, the C6-C10 aryl group is preferably phenyl.

[0023] In this invention, in R1 and R2, the number of carbon atoms of the aryl group in the C6-C10 aryl alkyl group can specifically be 6, 7, 8, 9, or 10; the number of carbon atoms of the alkyl group in the C6-C10 aryl alkyl group is preferably 1-3, specifically preferably 1, 2, or 3. In this invention, the C6-C... 10The aryl alkane is preferably -CH2-Ph ( ) or -CH2-CH2-Ph ( ).

[0024] In this invention, R1 and R2, together with the nitrogen atom to which they are attached, form a 5-6 membered heterocyclic group, which is particularly preferred. or .

[0025] In this invention, R1 and R2 are independently selected from R4-C(O)-( ).

[0026] In this invention, in R4, the number of carbon atoms in the alkyl group is preferably 1 to 6, specifically 1, 2, 3, 4, 5 or 6; the alkyl group is preferably -CH3, -CH2CH3, -CH2CH2CH3 or -CH2CH2CH2CH3.

[0027] In this invention, in R4, the substituent in the substituted alkyl group is preferably a cyano group, and the number of substituents in the substituted alkyl group is preferably 1 to 3, specifically 1, 2 or 3; the substituted alkyl group is specifically preferably -CH2-C≡N.

[0028] In this invention, the number of carbon atoms in the alkynyl group of R4 is preferably 1 to 6, specifically 1, 2, 3, 4, 5 or 6.

[0029] In this invention, in R4, the substituent in the substituted alkynyl group is preferably a halogen, and the halogen is preferably fluorine and / or chlorine.

[0030] In this invention, in R4, the number of carbon atoms in the heteroaryl group is preferably 6 to 10, specifically 6, 7, 8, 9, or 10; the heteroatom preferably includes nitrogen atoms, and the number of nitrogen atoms is preferably 1 to 2; the heteroaryl group is specifically preferably... , or .

[0031] In this invention, in R4, the substituent in the substituted heteroaryl group is preferably a halogen, and the halogen is preferably fluorine and / or chlorine; specifically, the substituted heteroaryl group is preferably... .

[0032] In this invention, in R4, the number of carbon atoms in the aryl group is preferably 6 to 10, specifically 6, 7, 8, 9 or 10; the aryl group is specifically preferably phenyl.

[0033] In this invention, in R4, the substituent in the substituted aryl group is preferably a hydroxyl group, and the number of substituents in the substituted aryl group is preferably 1 to 3, specifically 1, 2, or 3; the substituted aryl group is specifically preferably... .

[0034] In this invention, in R4, the number of carbon atoms in the alkoxy group is preferably 1 to 6, specifically 1, 2, 3, 4, 5 or 6; the alkoxy group is preferably -OCH3, -OCH2CH3 or -OC(CH3)3.

[0035] In this invention, the hydrazone-modified polycyclic hydroxypyridinone derivative preferably has the following structure: , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0036] This invention also provides a method for preparing the hydrazone-modified polycyclic hydroxypyridinone derivatives described in the above technical solution, comprising the following steps: The first compound having the structure shown in Formula a was subjected to a methylation reaction with trimethyloxonium tetrafluoroborate to obtain the second compound having the structure shown in Formula b. Formula a; Formula b; The second compound undergoes a substitution reaction with hydrazine or a substituted hydrazine to obtain a polycyclic hydroxypyridinone derivative with an hydrazone-modified structure as shown in Formula I.

[0037] Unless otherwise specified, the raw materials used in this invention are preferably commercially available products.

[0038] This invention involves a methylation reaction of a first compound having the structure shown in Formula a with trimethyloxonium tetrafluoroborate to obtain a second compound having the structure shown in Formula b. In this invention, the molar ratio of the first compound to trimethyloxonium tetrafluoroborate is preferably 1:1.5-3, more preferably 1:2. In this invention, the medium for the methylation reaction is preferably dichloromethane, more preferably anhydrous dichloromethane. In this invention, the volume ratio of the first compound to the methylation reaction medium is preferably 8.9 mmol:180-220 mL, more preferably 8.9 mmol:200 mL. In this invention, the temperature of the methylation reaction is preferably room temperature, and the time is preferably 3-5 h, more preferably 4 h; the methylation reaction is preferably carried out under stirring. After the methylation reaction is completed, this invention preferably further includes: solid-liquid separation of the obtained methylation reaction solution to obtain a filtrate; concentration of the filtrate under reduced pressure to obtain a residue; and purification of the residue by C18 reversed-phase column chromatography to obtain the second compound. In this invention, the solid-liquid separation method is preferably filtration or vacuum filtration; the eluent for the C18 reversed-phase column chromatography purification preferably includes methanol and water, and the volume ratio of methanol to water is preferably 2:8 to 9:1.

[0039] After obtaining the second compound, the present invention reacts the second compound with hydrazine or a substituted hydrazine to obtain the hydrazone-modified polycyclic hydroxypyridinone derivative having the structure shown in Formula I. In the present invention, the molar ratio of the second compound to hydrazine or a substituted hydrazine is preferably 1:1 to 3, more preferably 1:2. In the present invention, the medium for the substitution reaction is preferably ethanol. In the present invention, the molar ratio of the second compound to the medium for the substitution reaction is preferably 0.2 mmol: 8 to 12 mL, more preferably 0.2 mmol: 10 mL. In the present invention, the temperature of the substitution reaction is preferably 50 to 80°C, specifically preferably 50°C, 60°C, 70°C, or 80°C; the time is preferably 2 to 8 hours, specifically preferably 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours; the substitution reaction is preferably carried out under stirring. After the substitution reaction is completed, the present invention preferably further includes: cooling the obtained substitution reaction solution to room temperature, then concentrating under reduced pressure to remove the solvent to obtain a residue; dissolving the residue in dichloromethane, and washing it sequentially with distilled water, a saturated ammonium chloride aqueous solution, and a saturated brine solution to obtain an organic phase; and subjecting the organic phase to drying, a second periodic concentration under reduced pressure, and silica gel column chromatography to obtain the hydrazone-modified polycyclic hydroxypyridinone derivative. In the present invention, the drying agent used is preferably anhydrous sodium sulfate. In the present invention, the silica gel used for silica gel column chromatography is preferably 200-300 mesh in particle size, and the eluent is preferably dichloromethane and methanol, with a preferred volume ratio of dichloromethane to methanol of 80:1.

[0040] In this invention, the hydrazone-modified polycyclic hydroxypyridinone derivative is prepared according to the following formula: .

[0041] The present invention also provides a prodrug of the hydrazone-modified polycyclic hydroxypyridinone derivative described in the above technical solution, wherein the structure of the prodrug is: the oxygen in the hydroxyl group on the pyridine ring of the structure shown in Formula I forms an ester group or an ether group with R3; R3 is selected from , ;R a and R b Independently selected from H, C1~C3 alkyl, aryl; m is 1 or 2.

[0042] In this invention, the structure of the prodrug is that of the oxygen in the hydroxyl group on the pyridine ring of the structure shown in Formula I. When an ether group is formed, the method for preparing the prodrug preferably includes the following steps: Under alkaline conditions, a polycyclic hydroxypyridinone derivative with an hydrazone-modified structure as shown in Formula I and a fourth compound with a structure as shown in Formula d were subjected to... O - Alkylation reaction to obtain the prodrug; Formula d.

[0043] In this invention, the alkaline reagent providing the alkaline conditions is preferably one or more selected from alkali metal carbonates, alkali metal hydrides, and alkali metal hydroxides. In this invention, the alkali metal carbonate preferably includes one or more selected from potassium carbonate, sodium carbonate, lithium carbonate, and cesium carbonate. In this invention, the alkali metal hydride preferably includes sodium hydride. In this invention, the alkali metal hydroxide preferably includes one or more selected from sodium hydroxide, lithium hydroxide, and potassium hydroxide. In this invention, the molar ratio of the hydrazone-modified polycyclic hydroxypyridinone derivative to the fourth compound is preferably 1:1 to 3, more preferably 1:2. In this invention, the molar ratio of the hydrazone-modified polycyclic hydroxypyridinone derivative to the alkaline reagent is preferably 1:1.8 to 2.2, more preferably 1:2. In this invention, the... O The reaction system for the alkylation reaction preferably further includes potassium iodide, and the molar ratio of the hydrazone-modified polycyclic hydroxypyridinone derivative to potassium iodide is preferably 1:0.8~1.2, more preferably 1:1. In this invention, the... O -The medium for alkylation reaction is preferably N , N -Dimethylacetamide, more preferably anhydrous N , N -Dimethylacetamide. In this invention, the hydrazone-modified polycyclic hydroxypyridinone derivative and OThe preferred ratio of the medium used in the alkylation reaction is 0.1 mmol:0.8~1.2 mL, more preferably 0.1 mmol:1 mL. In this invention, the... O The preferred temperature for the alkylation reaction is 50-80°C, specifically 50°C, 60°C, 70°C, or 80°C; the preferred time is 2-10 hours, specifically 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours. O The alkylation reaction is preferably carried out under stirring conditions. O -After the alkylation reaction is completed, the present invention preferably further includes: obtaining O The alkylation reaction solution is cooled to room temperature, then diluted with ethyl acetate to obtain a diluted solution. The diluted solution is washed with distilled water to obtain an organic phase. The organic phase is then subjected to drying, vacuum concentration, and silica gel column chromatography purification to obtain the prodrug. In this invention, the drying agent used is preferably anhydrous Na₂SO₄. In this invention, the silica gel used for silica gel column chromatography purification preferably has a particle size of 200-300 mesh; the eluent preferably includes petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is preferably 6:1 to 3:1.

[0044] In this invention, the structure of the prodrug is that of the oxygen in the hydroxyl group on the pyridine ring of the structure shown in Formula I. When forming an ester group, the method for preparing the prodrug preferably includes the following steps: Under alkaline conditions, an hydrazone-modified polycyclic hydroxypyridinone derivative having the structure shown in Formula I is subjected to an O-phosphorylation reaction with a fifth compound having the structure shown in Formula e to obtain the prodrug; Formula e.

[0045] In this invention, the alkaline reagent providing the alkaline conditions is preferably one or more of an organic base, an alkali metal carbonate, or an alkali metal hydride; the organic base preferably includes triethylamine, N , N One or more of diisopropylethylamine and 4-dimethylaminopyridine; the alkali metal carbonate preferably includes one or more of potassium carbonate, sodium carbonate, and cesium carbonate; the alkali metal hydride preferably includes sodium hydride. In this invention, the molar ratio of the hydrazone-modified polycyclic hydroxypyridinone derivative to the fifth compound is preferably 1:1.0~3.0, more preferably 1:1.2~2.0, and even more preferably 1:1.5. In this invention, the molar ratio of the hydrazone-modified polycyclic hydroxypyridinone derivative to the basic reagent is preferably 1:1.0~3.0, more preferably 1:2. In this invention, the... O -The preferred medium for phosphorylation reaction is dichloromethane, tetrahydrofuran,N , N One or more of dimethylformamide and acetonitrile, more preferably anhydrous dichloromethane. In this invention, the hydrazone-modified polycyclic hydroxypyridinone derivative and... O The preferred ratio of phosphorylation reaction medium is 0.1 mmol: 0.8~2.0 mL, more preferably 0.1 mmol: 1.0 mL. In this invention, the... O The preferred temperature for the phosphorylation reaction is 20–40°C, more preferably 20–25°C; the preferred reaction time is 1–12 h, more preferably 2–8 h; O -The phosphorylation reaction is preferably carried out under stirring conditions. O After the phosphorylation reaction is completed, the present invention preferably further includes: cooling the reaction solution to room temperature, diluting it with ethyl acetate, washing it sequentially with distilled water, saturated sodium bicarbonate solution, and saturated brine, and separating the organic phase; drying the obtained organic phase with anhydrous Na2SO4, concentrating it under reduced pressure, and then purifying it by silica gel column chromatography to obtain the prodrug. In the present invention, the silica gel particle size used for silica gel column chromatography purification is preferably 200-300 mesh; the eluent preferably includes petroleum ether and ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is preferably 6:1-3:1.

[0046] This invention also provides pharmaceutically acceptable salts of the hydrazone-modified polycyclic hydroxypyridinone derivatives described in the above-described technical solutions. In this invention, the pharmaceutically acceptable salts preferably include those derived from inorganic acids, organic acids, or inorganic bases. In this invention, the inorganic acid is preferably one or more of hydrochloric acid, hydrobromic acid, sulfuric acid, and phosphoric acid. In this invention, the organic acid is preferably one or more of oxalic acid, maleic acid, succinic acid, and citric acid. In this invention, the inorganic base is preferably one or more of hydroxides, carbonates, and bicarbonates of metal cations; the metal cation is preferably one or more of lithium, sodium, potassium, calcium, magnesium, and aluminum.

[0047] The present invention also provides the use of the hydrazone-modified polycyclic hydroxypyridinone derivatives, the prodrugs, or the pharmaceutically acceptable salts described above in the preparation of anti-influenza virus drugs.

[0048] In this invention, the influenza virus preferably includes influenza A virus and / or influenza B virus, and more preferably influenza A virus.

[0049] In this invention, the influenza A virus strain is preferably obtained by infecting MDCK cells to obtain IAV.

[0050] The following detailed description, in conjunction with embodiments, illustrates the hydrazone-modified polycyclic hydroxypyridinone derivatives, their preparation methods, and applications provided by the present invention. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0051] Example 1 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-8-hydroxy-7-hydrazone-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A1: .

[0052] 1) Preparation of compound 2 Compound 1 (4.30 g, 8.9 mmol) was dissolved in 200 mL of anhydrous dichloromethane, and trimethyloxonium tetrafluoroborate (2.63 g, 17.8 mmol) was added. The mixture was stirred at room temperature for 4 h. The resulting reaction solution was filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by C18 reversed-phase column chromatography (eluent: methanol and water in a volume ratio of 2:8–9:1) to give product 2 (3.59 g, 81%).

[0053] 1 H NMR (500 MHz, CDCl3) d 7.11 (m, 4H), 7.04 (dd, J = 8.6, 4.1 Hz, 1H), 6.81–6.75 (m, 2H), 6.10 (d, J = 6.6 Hz, 1H), 5.52 (s, 1H), 5.26 (dd, J = 13.9, 2.6 Hz, 1H), 4.74 (dd, J = 13.6, 2.5 Hz, 1H), 4.57 (dd, J = 10.2, 3.0 Hz, 1H), 4.10 (d, J = 13.9 Hz, 1H), 3.89 (dd, J = 10.9, 3.0 Hz, 1H), 3.85 (s, 3H), 3.69(dd, J = 11.9, 3.2 Hz, 1H), 3.55–3.43 (m, 2H), 2.87 (ddd, J= 14.7, 11.9, 3.4 Hz,1H). HRMS (ESI) m / z cald. for ESI-MS(m / z): C 25 H 22 F2N3O4S [M+H] + : 498.1294, found498.1298. 2) Preparation of compound A1 Compound 2 (100 mg, 0.2 mmol) was dissolved in 10 mL of ethanol, and hydrazine (13 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was complete, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A1 (83.6 mg, 84%).

[0054] 1 H NMR (500 MHz, DMSO- d 6 ) d 7.39 (dd, J = 8.6, 4.7 Hz, 2H), 7.11 (dtd, J =15.3, 8.0, 1.5 Hz, 2H), 7.01 (dd, J = 6.8, 2.5 Hz, 1H), 6.91–6.85 (m, 1H), 6.79(dd, J = 14.7, 1.5 Hz, 1H), 5.85 (dd, J = 7.0, 3.0 Hz, 1H), 5.67 (s, 1H), 5.43(dd, J = 14.3, 2.4 Hz, 1H), 4.41 (d, J = 13.4 Hz, 1H), 4.35 (dd, J = 10.0, 3.0 Hz, 1H), 4.08 (d, J = 14.2 Hz, 1H), 3.92 (dd, J = 10.9, 3.0 Hz, 1H), 3.59 (dd, J=11.6, 3.2 Hz, 1H), 3.35 (s, 1H), 3.25 (t, J = 10.4 Hz, 1H), 3.21–3.13 (m, 1H), 2.74 (s, 1H). 13 C NMR (151 MHz, DMSO- d 6 ) d 158.4, 157.4, 156.0, 136.0, 133.4,133.0, 132.8, 130.1, 129.8, 128.5, 126.91, 125.0, 124.9, 124.8, 117.0, 116.9,112.5, 92.4, 73.3, 69.0, 68.5, 66.0, 45.2, 23.6. HRMS (ESI) m / z cald. forESI-MS(m / z):C 24 H 22 F2N5O3S [M+H] + : 498.1406, found 498.1418. Example 2 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-methylhydrazone)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A2 .

[0055] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and methylhydrazine (18 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A2 (81.8 mg, 80%).

[0056] 1 H NMR (600 MHz, DMSO- d 6 ) d 7.50 (d, J = 7.4 Hz, 1H), 7.47 – 7.38 (m, 2H),7.17 (ddd, J = 8.4, 7.0, 1.5 Hz, 1H), 7.13 (dd, J = 8.0, 1.5 Hz, 1H), 6.93 (dd, J =7.9, 1.5 Hz, 1H), 6.82 (ddd, J = 7.9, 7.0, 1.5 Hz, 1H), 6.54 (d, J = 7.4 Hz, 1H),5.88 (s, 1H), 5.37 (dd, J = 14.5, 2.2 Hz, 1H), 4.67 (dd, J = 10.0, 3.2 Hz, 1H),4.44 (dd, J = 13.2, 2.5 Hz, 1H), 4.09 (d, J = 14.4 Hz, 1H), 3.96 (dd, J = 10.9, 3.2Hz, 1H), 3.79 (t, J = 10.5 Hz, 1H), 3.71 (dd, J = 11.4, 3.4 Hz, 1H), 3.47 (td, J =11.7, 2.8 Hz, 1H), 3.15 (ddd, J = 13.4, 11.7, 3.6 Hz, 1H), 2.43 (s, 3H). 13 C NMR(151 MHz, DMSO- d 6 ) d 160.0, 150.1, 146.2, 139.8, 136.8, 133.6, 132.0, 130.5,129.0, 128.9, 127.2, 125.3, 125.3, 125.2, 117.3, 117.1, 116.6, 101.0, 74.0,70.5, 68.4, 65.9, 46.2, 37.2, 23.6. HRMS (ESI) m / z cald. for ESI-MS(m / z):C 25 H 24F2N5O3S [M+H] + : 512.1563, found 512.1564. Example 3 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-[2-methyl-2-(pivaloyloxy)hydrazone]-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A3: .

[0057] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and Boc-methylhydrazine (58 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A3 (97.5 mg, 80%).

[0058] 1 H NMR (600 MHz, DMSO- d 6 ) d 7.43–7.35 (m, 2H), 7.13–7.07 (m, 2H), 7.04(d, J = 6.4 Hz, 1H), 6.88 (d, J = 7.3 Hz, 1H), 6.76 (ddd, J = 14.0, 8.1, 4.7 Hz,1H), 5.61 (d, J = 6.1 Hz, 1H), 5.42 (d, J = 15.6 Hz, 1H), 4.40 (t, J = 13.4 Hz, 2H), 4.08 (d, J = 14.2 Hz, 1H), 3.92 (dd, J = 10.7, 3.0 Hz, 1H), 3.60 (dd, J=11.4, 3.1 Hz, 1H), 3.31 (t, J = 10.4 Hz, 2H), 3.21 (dd, J = 11.7, 9.6 Hz, 1H), 2.85 (s, 3H), 2.79–2.72 (m, 1H), 1.33 (s, 9H). 13 C NMR (151 MHz, DMSO- d 6 ) d 163.7, 158.2, 157.6, 155.6, 151.9, 150.3, 147.9, 146.2, 136.2, 133.3, 132.8,131.6, 129.9, 129.6, 128.5, 127.1, 124.9, 117.0, 116.9, 114.6, 93.9, 73.5,68.8, 68.4, 66.0, 45.3, 28.3, 23.6. HRMS (ESI) m / z cald. for ESI-MS(m / z):C 30 H 31 F2N5O3S [M+H] + : 612.2087, found 612.2112. Example 4 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-ethylhydrazone)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A4: .

[0059] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and ethylhydrazine (24 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A4 (87.2 mg, 82%).

[0060] 1 H NMR (500 MHz, DMSO- d 6 ) d 8.62 (s, 1H), 7.38 (dd, J = 8.2, 5.5 Hz, 2H),7.12 – 7.04 (m, 2H), 6.95 (d, J = 6.7 Hz, 1H), 6.85 (d, J = 7.8 Hz, 1H), 6.78 –6.71 (m, 1H), 5.85 (d, J = 6.7 Hz, 1H), 5.66 (s, 1H), 5.44 (dd, J = 14.2, 2.3 Hz,1H), 4.90 (s, 1H), 4.40 (dd, J = 13.7, 2.5 Hz, 1H), 4.33 (dd, J = 10.0, 3.1 Hz,1H), 4.06 (d, J = 14.2 Hz, 1H), 3.89 (dd, J = 10.7, 3.1 Hz, 1H), 3.58 (dd, J =11.6, 3.2 Hz, 1H), 3.27 (t, J = 10.4 Hz, 1H), 3.17 (t, J = 11.5 Hz, 1H), 2.76 –2.64 (m, 3H), 0.85 (t, J = 7.1 Hz, 3H). 13 C NMR (151 MHz, DMSO- d 6 ) d 156.8, 156.7,155.5, 135.0, 132.2, 131.8, 131.0, 128.8, 128.6, 127.2, 125.9, 123.9, 123.8,123.7, 115.8, 115.7, 111.8, 91.8, 72.2, 67.7, 67.3, 64.9, 44.2, 28.3, 22.4,12.1. HRMS (ESI) m / z cald. for ESI-MS(m / z): C 26 H26 F2N5O3S [M+H] + : 526.1719, found 526.1714. Example 5 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-[2-(2-hydroxyethyl)hydrazone]-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A5: .

[0061] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and 2-hydrazinoethanol (31 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A5 (84.5 mg, 78%).

[0062] 1 H NMR (600 MHz, DMSO- d 6 ) d 7.43–7.35 (m, 2H), 7.15–7.06 (m, 3H), 6.96(dd, J = 10.9, 6.8 Hz, 1H), 6.91–6.83 (m, 1H), 6.80–6.74 (m, 1H), 5.83 (dt, J =20.8, 7.5 Hz, 1H), 5.69–5.63 (m, 1H), 5.48–5.40 (m, 1H), 4.61 (s, 1H), 4.41(d, J = 11.1 Hz, 1H), 4.34 (d, J = 7.2 Hz, 1H), 4.07 (dt, J = 8.6, 4.8 Hz, 2H), 3.90 (dd, J = 7.7, 3.3 Hz, 1H), 3.58 (d,J = 11.5 Hz, 1H), 3.30–3.12 (m, 3H), 2.71 (d, J = 4.6 Hz, 2H). 13 C NMR (151 MHz, DMSO- d 6 ) d 157.8, 156.1, 136.1, 136.0,133.4, 133.0, 132.1, 130.0, 128.4, 128.4, 126.9, 125.0, 116.9, 116.8, 112.9,92.8, 91.9, 73.2, 68.9, 68.5, 68.4, 66.0, 59.4, 53.1, 45.2, 23.6. HRMS (ESI)m / z cald. for ESI-MS(m / z): C 26 H 26 F2N5O4S [M+H] + : 542.1668, found 542.1679. Example 6 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-[2-(2,2,2-trifluoroethyl)hydrazone]-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A6: .

[0063] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and 2,2,2-trifluoroethylhydrazine (46 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A6 (86.9 mg, 75%).

[0064] 1 H NMR (600 MHz, DMSO- d 6 ) d 7.39 (d, J J = 6.2 Hz, 2H), 7.09 (dd, J J = 7.4, 1.7Hz, 2H), 6.98 (d, J J = 6.8 Hz, 1H), 6.85 (d, J J = 7.3 Hz, 1H), 6.74 (dd, J J = 7.9, 6.2Hz, 1H), 5.88 (d, J J = 6.8 Hz, 1H), 5.67 (s, 1H), 5.44 (dd, J J = 14.3, 1.9 Hz, 2H),4.41 (t, J J = 9.6 Hz, 2H), 4.35 (dd, J J = 10.0, 3.1 Hz, 1H), 4.07 (d, J J = 14.2 Hz,1H), 3.91 (dd, J J = 10.8, 3.0 Hz, 1H), 3.59 (dd, J J = 11.3, 3.2 Hz, 1H), 3.30–3.25(m, 2H), 3.19 (t, J J = 13.0 Hz, 1H), 1.21 (d, J J = 6.6 Hz, 2H). 13 13C NMR (151 MHz,DMSO- d 6 d6) d 163.7, 159.5, 158.0, 157.6, 156.1, 136.0, 133.4, 132.9, 132.2,129.9, 129.7, 128.4, 127.0, 125.1, 125.0, 124.9, 116.9, 116.8, 113.3, 93.6,73.4, 68.9, 68.5, 66.0, 45.2, 23.6. HRMS (ESI) m / z calcd. for ESI-MS(m / z): C26H22F5N5O3S [M+H]+ 26 26 23 F5N5O3S [M+H]+ + : 580.1437, found 580.1461. Example 7 ( R )-12-[(S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-cyclobutylhydrazone)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A7: .

[0065] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and cyclobutylhydrazine (34 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A7 (86.8 mg, 79%).

[0066] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 28 H 28 F2N5O3S [M+H] + : 552.1876, found 552.1869. Example 8 In Example 7, cyclobutylhydrazine was replaced with cyclopentylhydrazine to prepare A8, and the rest was the same as in Example 7.

[0067] Example 9 In Example 7, cyclobutylhydrazine was replaced with cyclohexylhydrazine to prepare A9, and the rest was the same as in Example 7.

[0068] Example 10 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-pyrrolidineimino)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A10: .

[0069] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and then... N-Pyrrolidone (34 mg, 0.4 mmol) was reacted with the solution at 50 °C for 4 h. After the reaction was complete, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A10 (89.3 mg, 81%).

[0070] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 28 H 28 F2N5O3S [M+H] + : 552.1876, found 552.1882. Example 11 The difference from Example 10 is that: N -Pyrrolidineamine is replaced with N -Pyridylamino, preparation of A11, other procedures are the same as in Example 10.

[0071] Example 12 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-phenylhydrazone)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A12: .

[0072] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and phenylhydrazine (43 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A9 (92.7 mg, 81%).

[0073] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 30 H 26F2N5O3S [M+H] + : 574.1719, found 574.1713. Example 13 The difference from Example 12 is that phenylhydrazine is replaced with benzylhydrazine to prepare A13, and the rest is the same as in Example 12.

[0074] Example 14 The difference from Example 12 is that phenylhydrazine is replaced with phenylethylhydrazine to prepare A14, and the rest is the same as in Example 12.

[0075] Example 15 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-acetylhydrazone)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A15: .

[0076] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and acetylhydrazine (30 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A15 (90.5 mg, 84%).

[0077] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 26 H 24 F2N5O4S [M+H] + : 540.1512, found 540.1523. Example 16 The difference from Example 15 is that acetylhydrazine is replaced with propionylhydrazine to prepare A16, otherwise the same as in Example 15.

[0078] Example 17 The difference from Example 15 is that acetylhydrazine is replaced with n-butyrylhydrazine to prepare A17, otherwise the same as in Example 15.

[0079] Example 18 The difference from Example 15 is that acetylhydrazine is replaced with valerylhydrazine to prepare A18, otherwise the same as in Example 15.

[0080] Example 19 The difference from Example 15 is that acetylhydrazine is replaced with cyanoacetylhydrazine to prepare A19, otherwise the same as in Example 15.

[0081] Example 20 The difference from Example 15 is that acetylhydrazine is replaced with oxalamide hydrazine to prepare A20, otherwise the same as in Example 15.

[0082] Example 21 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-fluoroisonicotinamide hydrazone)-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A21: .

[0083] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and 3-fluoroisonicotinamide (62 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A21 (100.6 mg, 81%).

[0084] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 30 H 24 F3N6O4S [M+H] + : 621.1527, found 621.1522. Example 22 The difference from Example 21 is that 3-fluoroisonicotinamide hydrazide is replaced with 2-pyridinecarboxylhydrazide to prepare A22, and the rest is the same as in Example 21.

[0085] Example 23 The difference from Example 21 is that 3-fluoroisonicotinamide hydrazide is replaced with 3-pyridinecarboxylhydrazide to prepare A23, and the rest is the same as in Example 21.

[0086] Example 24 The difference from Example 21 is that 3-fluoroisonicotinamide is replaced with isonicotinamide to prepare A24, and the rest is the same as in Example 21.

[0087] Example 25 The difference from Example 21 is that 3-fluoroisonicotinamide is replaced with o-hydroxybenzoylhydrazine to prepare A25, and the rest is the same as in Example 21.

[0088] Example 26 ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-[2-(fluorenylmethoxycarbonyl)hydrazone]-3,4,12,12a-tetrahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A26: .

[0089] Compound 2 (100 mg, 0.2 mmol) obtained in Example 1 was dissolved in 10 mL of ethanol, and 9H-fluorene-9-methylhydrazine carbamate (102 mg, 0.4 mmol) was added. The reaction mixture was stirred at 50 °C for 4 h. After the reaction was completed, the reaction system was cooled to room temperature. The solvent was removed by concentration under reduced pressure, and the residue was then dissolved in 25 mL of dichloromethane. The organic phase was washed successively with distilled water, saturated ammonium chloride aqueous solution, and saturated brine (50 mL each). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was further purified by silica gel (200-300 mesh) column chromatography (eluent: dichloromethane:methanol (v / v) = 80:1) to give product A26 (126.0 mg, 88%).

[0090] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 39 H 32 F2N5O5S [M+H] + : 720.2087, found 720.2082. Example 27 The difference from Example 15 is that acetylhydrazine is replaced with methyl hydrazine for the preparation of A27, otherwise the same as in Example 15.

[0091] Example 28 The difference from Example 15 is that acetylhydrazine is replaced with ethyl hydrazine for the preparation of A28, otherwise the same as in Example 15.

[0092] Example 29 Preparation of prodrug A4-M ( R )-12-[( S Preparation of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiapine-11-yl]-7-hydroxy-8-(2-ethylhydrazone)-7-(methoxycarbonyloxymethoxy)-3,4,6,8,12,12a-hexahydro-1H-oxazino[3,4-c]pyrido[2,1-f][1,2,4]triazin-6-one A4-M: .

[0093] The compound A4 (53 mg, 0.1 mmol) obtained in Example 4 was dissolved in 1 mL of anhydrous water. N , N Dimethylacetamide was added sequentially with cesium carbonate (65 mg, 0.2 mmol), chloromethyl methyl carbonate (25 mg, 0.2 mmol), and potassium iodide (17 mg, 0.1 mmol). The reaction mixture was stirred at 50 °C for 6 h. After the reaction was complete, the mixture was cooled to room temperature, diluted with ethyl acetate (30 mL), and washed thoroughly with distilled water (100 mL × 3). The organic phase was dried over anhydrous Na₂SO₄, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel (200–300 mesh) column chromatography (eluent: petroleum ether and ethyl acetate in a volume ratio of 6:1–3:1) to give product A4-M (53.9 mg, 88%).

[0094] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 29 H 30 F2N5O6S [M+H] + : 614.1880, found 614.1882. Example 30: Preparation of the prodrug A6-M .

[0095] The compound A6 (57 mg, 0.1 mmol) obtained in Example 6 was dissolved in 1 mL of anhydrous water. N , NDimethylacetamide was added sequentially with cesium carbonate (65 mg, 0.2 mmol), chloromethyl methyl carbonate (25 mg, 0.2 mmol), and potassium iodide (17 mg, 0.1 mmol). The reaction mixture was stirred at 50 °C for 6 h. After the reaction was complete, the mixture was cooled to room temperature, diluted with ethyl acetate (30 mL), and washed thoroughly with distilled water (100 mL × 3). The organic phase was dried over anhydrous Na₂SO₄, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: petroleum ether and ethyl acetate in a volume ratio of 6:1 to 3:1) to give product A6-M (59.2 mg, 89%).

[0096] HRMS (ESI) m / z cald. for ESI-MS(m / z): C 29 H 27 F5N5O6S [M+H] + : 668.1597, found 668.1592. Performance testing 1) Evaluation of in vitro anti-influenza virus activity The inhibitory activity of the compound against influenza virus replication was evaluated using a 293T-Gluc reporter cell system.

[0097] HEK293T-Gluc cells are reporter cells that stably express Gluc negative-strand RNA. When infected with influenza virus, they can produce Gluc luciferase signals, the intensity of which is positively correlated with the level of viral replication.

[0098] Virus strain: IAV (titer 10⁷) was obtained by infecting MDCK cells and stored at -80°C.

[0099] Sample preparation: The test compound was dissolved in DMSO to prepare an appropriate initial concentration, and then serially diluted using culture medium.

[0100] Assay Method: HEK293T-Gluc cells were seeded in 96-well plates and cultured at 37°C in a 5% CO2 incubator for 24 h. Different concentrations of the test compound were pre-treated for 2 h, followed by inoculation with influenza virus at an MOI of 0.25. After 24 h of culture, luciferase activity in infected cells was measured, and the EC50 of each sample was calculated. 50 The experiment was repeated three times independently, and the results are shown in Table 1.

[0101] 2) Cytotoxicity test The cytotoxicity of the compound to host cells was determined using the CCK-8 (Cell Counting Kit-8) method.

[0102] HEK293T-Gluc cells were seeded at 1000 cells per well (100 μL per well) in three replicates of 96-well clear plates and cultured overnight. The next day, six 2-fold serial dilutions of the test compound solution, starting at 100 μM, were added. After culturing for another 48 h, 10 μL of CCK-8 was added to each well, and the plates were incubated at 37°C for 90 min. The absorbance at 450 nm was measured using a Victor X5 microplate reader to calculate the half-maximal cytotoxic concentration (MCC). 50 The experiment was independently repeated three times, and the results are shown in Table 1.

[0103] Table 1 lists the in vitro inhibitory activities (EC50) of some of the target compounds of this invention against influenza virus. 50 ), cytotoxicity (CC) 50 ) and selection index (SI=CC) 50 / EC 50 Baloxavir acid (BXA) was used as the positive control drug.

[0104] Table 1. In vitro anti-influenza virus activity and cytotoxic effects of some derivatives.

[0105] The experimental results show that all the compounds tested in Table 1 have inhibitory effects on influenza A virus. Some compounds have better activity at the cellular level than the positive control drug baloxaviric acid, indicating that this type of structure has further research value.

[0106] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A class of hydrazone-modified polycyclic hydroxypyridinone derivatives, characterized in that, It has the structure shown in Equation I: Formula I; In Formula I, R1 and R2 are independently selected from H, C1~C6 alkyl, C3~C7 cycloalkyl, C1~C6 hydroxyalkyl, C1~C6 haloalkyl, C6~C10 aryl, C6~C10 arylalkyl or R4-C(O)-; Alternatively, R1 and R2 together with the nitrogen atoms they are attached to form 5-6 membered heterocyclic groups; R4 is selected from alkyl, substituted alkyl, alkynyl, substituted alkynyl, carbamoyl, heteroaryl, substituted heteroaryl, aryl, substituted aryl, alkoxy, or 9-fluorenoxycarbonyl.

2. The hydrazone-modified polycyclic hydroxypyridinone derivative according to claim 1, characterized in that, In R1 and R2, the number of carbon atoms in the C1~C6 alkyl group is 1~3; The C3-C7 cycloalkyl group has 4-6 carbon atoms; The C1-C6 hydroxyalkyl group has 1-3 carbon atoms; The C1-C6 haloalkyl group has 1-3 carbon atoms, and the halogen includes fluorine; The number of carbon atoms in the C6~C10 arylalkyl group is 1~3; In R4, the alkyl group has 1 to 6 carbon atoms; The substituted alkyl group is a cyano group; The number of carbon atoms in the alkynyl group is 1 to 6; The substituent in the substituted alkynyl group is a halogen; The heteroaryl group has 6 to 10 carbon atoms, and the heteroatom includes nitrogen atoms, with 1 to 2 nitrogen atoms. The substituents in the substituted heteroaryl group are halogens; The aryl group has 6 to 10 carbon atoms; The substituent in the substituted aryl group is a hydroxyl group; The number of carbon atoms in the alkoxy group is 1 to 6.

3. The hydrazone-modified polycyclic hydroxypyridinone derivative according to claim 1 or 2, characterized in that, In R1 and R2, the C1~C6 alkyl group is -CH3 or -CH2CH3; The C3-C7 cycloalkyl group is cyclobutyl, cyclopentyl, or cyclohexyl; The C1~C6 hydroxyalkyl group is -CH2CH2OH; The C1~C6 haloalkyl group is -CH2CF3; The C6-C10 aryl group is phenyl; The C6~C10 arylalkyl group is -CH2-Ph or -CH2-CH2-Ph; R1 and R2, together with the nitrogen atoms they are attached to, form 5-6 membered heterocyclic groups. or ; In R4, the alkyl group is -CH3, -CH2CH3, -CH2CH2CH3 or -CH2CH2CH2CH3; The substituted alkyl group is -CH2-C≡N; The heteroaryl group is , or ; The substituted heteroaryl group is ; The substituted aryl group is ; The alkoxy group is -OCH3, -OCH2CH3 or -OC(CH3)3.

4. The hydrazone-modified polycyclic hydroxypyridinone derivative according to claim 1, characterized in that, It has the following structure: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 5. The method for preparing the hydrazone-modified polycyclic hydroxypyridinone derivative according to any one of claims 1 to 4, characterized in that, Includes the following steps: The first compound having the structure shown in Formula a was subjected to a methylation reaction with trimethyloxonium tetrafluoroborate to obtain the second compound having the structure shown in Formula b. Formula a; Formula b; The second compound is subjected to a substitution reaction with hydrazine or a substituted hydrazine to obtain the hydrazone-modified polycyclic hydroxypyridinone derivative having the structure shown in Formula I.

6. The preparation method according to claim 5, characterized in that, The methylation reaction was carried out at room temperature for 3-5 hours. The substitution reaction is carried out at a temperature of 50-80°C for 2-8 hours.

7. The prodrug of the hydrazone-modified polycyclic hydroxypyridinone derivative according to any one of claims 1 to 4, characterized in that, The structure of the prodrug is as follows: the oxygen in the hydroxyl group on the pyridine ring of the structure shown in Formula I forms an ester group or an ether group with R3. R3 is selected from H, , ;R a and R b Independently selected from H, C1~C3 alkyl, aryl; m is 1 or 2.

8. A pharmaceutically acceptable salt of the hydrazone-modified polycyclic hydroxypyridinone derivative according to any one of claims 1 to 4.

9. The use of the hydrazone-modified polycyclic hydroxypyridinone derivative of any one of claims 1 to 4, the prodrug of claim 7, or the pharmaceutically acceptable salt of claim 8 in the preparation of an antiviral drug.

10. The application according to claim 9, characterized in that, The influenza virus in question is influenza A virus and / or influenza B virus.

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