A novel cytidine derivative, pharmaceutical composition thereof and use thereof

Abstract

The application discloses a novel cytidine derivative compound, a pharmaceutical composition of the compound and application of the compound, and the compound is shown as formula (I). The compound can be used for preparing an antiviral infection medicine.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of pharmaceutical chemistry, and particularly to a novel cytidine derivative, its pharmaceutical composition, and its uses. Background Technology

[0002] Influenza (flu) is an infectious disease caused by the influenza virus, characterized by high morbidity and mortality. The influenza virus can spread rapidly through the air, causing respiratory infections. Immunocompromised individuals are prone to serious complications such as pneumonia or acute respiratory failure. According to a 2019 report by the World Health Organization, an estimated 1 billion influenza cases occur globally each year, including 3 to 5 million severe cases and 290,000 to 650,000 deaths. While vaccination is an effective means of mitigating influenza outbreaks, vulnerable groups such as children, the elderly, those with chronic respiratory diseases, and pregnant women are more susceptible to serious complications and require timely antiviral treatment to reduce this risk. Furthermore, vaccine development is often delayed, and effective antiviral treatment can delay or block viral transmission.

[0003] Although several anti-influenza drugs are currently on the market, such as oseltamivir, zanamivir, peramivir, baloxavir, lanimivir, and favipiravir, which have played a significant role in inhibiting the influenza virus, the development of anti-influenza drugs remains a long and arduous task due to the high variability of the influenza virus, concerns about the emergence of drug-resistant strains or side effects, and the global pandemic of novel influenza viruses with high pathogenicity or lethality. Therefore, the field still desires to develop anti-influenza drugs with novel structures. Summary of the Invention

[0004] The inventors have developed a novel cytidine derivative compound that exhibits antiviral activity and low cytotoxicity.

[0005] In one aspect, this invention provides a novel cytidine derivative compound, tautomer, stereoisomer, and pharmaceutically acceptable salt thereof, as shown in (I):

[0006]

[0007] In formula (I),

[0008] R1, R2, R x6 and R x7 Each element is independently selected from hydrogen, deuterium, hydroxyl, C1-C8 alkoxy, halogen, C1-C8 alkyl,

[0009]

[0010] Among them, n1 and n2 are independently selected from 0, 1, 2 or 3 respectively;

[0011] R a and R b Each group is independently selected from hydroxyl, substituted with one or more groups A, or unsubstituted with the following groups: alkyl, alkoxy, alkenyl, cycloalkyl, aryl, aryloxy, arylalkyl, alkylaryl;

[0012] R c and R d Each is independently selected from hydrogen, or from C1-C8 alkyl groups substituted with or unsubstituted with one or more A groups;

[0013] R3 and R4 may be the same or different, and are independently selected from hydrogen, or R3 and R4 cannot both be hydrogen;

[0014] Where, n a n b n and n3 are each independently selected from 0, or 1, or 2, or 3, or 4, or 5;

[0015] n4 is selected from 0, 1, 2, 3 or 4;

[0016] R5 and R6 may be the same or different, and are independently selected from hydrogen, C1-C8 alkyl groups substituted or unsubstituted with one or more groups A; or R5, R6 and the carbon atom to which they are attached are cycloalkyl groups;

[0017] R7 is a hydrogen, halogen, amino, or C1-C8 alkyl group substituted or unsubstituted with one or more A groups;

[0018] Z is selected from in,

[0019] n5 can be 0, 1, 2, 3, 4, or 5 independently;

[0020] R8 is selected from H, hydroxyl, halogen, and the following groups substituted or unsubstituted by one or more groups A: amino, C1-C8 alkyl, aryl, alkyloxy, aminoalkyl, C1-C8 alkylaryl, arylcarbonyl, and C1-C8 alkylcarbonyloxy.

[0021] R e and R f The following groups are selected independently from hydrogen, substituted with or unsubstituted by one or more groups A: C1-C8 alkyl, C3-C8 cycloalkyl, heterocycloalkyl, C6-C18 aryl, heteroaryl, and non-aromatic heterocyclic groups;

[0022] R X1 R X2 R X3 R X4 They are each independently selected from hydrogen and deuterium;

[0023] R X5 Selected from hydrogen, deuterium, and cyano groups;

[0024] R X8 Selected from hydrogen, deuterium, azide, and the following groups substituted or unsubstituted by one or more groups A: alkyl, alkoxy, alkenyl, cycloalkyl, aryl, aryloxy, arylalkyl, alkylaryl;

[0025] In particular,

[0026] R X1 R X2 R X3 R X4 R X5 R X6 R X7 and R X8 It cannot be hydrogen at the same time;

[0027] When R1 and R2 are independently selected from hydroxyl, At the same time R x6 and R x7 When R is hydrogen or deuterium, respectively, X5 and R X8 It cannot be distinguished independently as hydrogen or deuterium.

[0028] The group A is: hydroxyl, carboxyl, amino, halogen, cyano, aldehyde, nitro, trifluoromethyl, C3-C8 cycloalkyl, C1-C8 alkoxy, chlorophenylcarbonyl.

[0029] In some embodiments, the present invention provides a novel cytidine derivative compound, tautomer, stereoisomer, and pharmaceutically acceptable salt thereof as shown in formula (II):

[0030]

[0031] The substituents in formula (II) are defined as described above.

[0032] In some embodiments, the present invention provides a novel cytidine derivative compound, tautomer, stereoisomer, and pharmaceutically acceptable salt thereof of formula (III):

[0033]

[0034] The substituents in formula (Ⅲ) are defined as described above.

[0035] In some embodiments, the present invention provides a variety of novel cytidine derivatives, tautomers, stereoisomers, and pharmaceutically acceptable salts thereof of formula (IV):

[0036]

[0037] The substituents in formula (IV) are defined as described above.

[0038] In some implementations, R1 and R2 in formulas (I)-(IV) above are both hydroxyl groups.

[0039] In some embodiments, in formulas (I)-(IV) above, R1 is a hydroxyl group, and R2 is selected from hydrogen, halogen, C1-C8 alkoxy, C1-C8 alkyl, ... in,

[0040] The n1 and n2 mentioned above are independently selected from 0, 1, 2 or 3 respectively;

[0041] R a and R b Each group is independently selected from hydroxyl, substituted with one or more groups A, or unsubstituted with the following groups: alkyl, alkoxy, alkenyl, cycloalkyl, aryl, aryloxy, arylalkyl, alkylaryl; further, R a and R b Each is independently preferred from hydroxyl, alkyl group substituted or unsubstituted with one or more groups A, and alkyloxy group substituted or unsubstituted with one or more groups A;

[0042] R c and R d Each is independently selected from hydrogen, or from C1-C8 alkyl groups substituted with or unsubstituted with one or more A groups.

[0043] In some more specific embodiments, in formulas (I)-(IV) above, R1 is a hydroxyl group, and R2 is selected from hydrogen, halogen, C1-C8 alkoxy, C1-C8 alkyl, in,

[0044] n1, n2, R a R b R c and R d As defined above.

[0045] In some embodiments, in formulas (I)-(IV) above, R2 is a hydroxyl group, and R1 is selected from hydrogen, halogen, C1-C8 alkoxy, C1-C8 alkyl, ... in,

[0046] n1, n2, R a R b R c and R d As defined above.

[0047] In some embodiments, in formulas (I)-(IV) above, R1 and R2 are not hydroxyl groups, but are independently selected from hydrogen, halogen, C1-C8 alkoxy, C1-C8 alkyl, etc. in,

[0048] The above n1, n2, R a R b R c and R d As defined above.

[0049] In some implementations, in equations (I)-(IV) above, R X1 R X2 R X3 and R X4 They are selected independently from hydrogen and deuterium, respectively.

[0050] In some implementations, in equations (I)-(IV) above, R X5 Selected from hydrogen, deuterium, and cyano groups.

[0051] In some implementations, in equations (I)-(IV) above, R X6 It is selected from hydrogen, deuterium, halogen, and C1-C8 alkyl.

[0052] In some more specific implementations, in equations (I)-(IV) above, R X6 Selected from hydrogen or deuterium.

[0053] In some implementations, in equations (I)-(IV) above, R X7 It is selected from hydrogen, deuterium, halogen, and C1-C8 alkyl.

[0054] In some more specific implementations, in equations (I)-(IV) above, R X7 Selected from hydrogen, deuterium, or halogens.

[0055] In some implementations, in equations (I)-(IV) above, R X8 Selected from hydrogen, deuterium, azide, and the following groups substituted or unsubstituted by one or more groups A: alkyl, alkoxy, alkenyl, cycloalkyl, aryl, aryloxy, arylalkyl, alkylaryl.

[0056] In some more specific implementations, in equations (I)-(IV) above, R X8 Selected from hydrogen, deuterium, or azide groups.

[0057] Specifically, in formulas (I)-(IV) above, when R1 and R2 are independently selected from hydroxyl groups, At that time, R X1 R X2 R X3 RX4 R X5 R X6 R X7 and R X8 It cannot be hydrogen at the same time.

[0058] In some implementations, in formulas (I)-(II) above, R4 is hydrogen, and R3 is... in,

[0059] In some implementation schemes, the above n a and n b Each is independently selected from 0, 1, 2, and 3;

[0060] In some more specific implementation schemes, n a =0;

[0061] In some more specific implementation schemes, n a =1;

[0062] In some more specific implementation schemes, n b =1;

[0063] In some more specific implementation schemes, n b It is 2;

[0064] In some implementations, n3 is selected from 0, 1, 2, and 3;

[0065] In some more specific implementations, n3 is 0;

[0066] In some more specific implementations, n3 is 2;

[0067] In some more specific implementations, n3 is 3;

[0068] In some implementations, n4 is selected from 0, 1, and 2;

[0069] In some more specific implementations, n4 is 0;

[0070] In some more specific implementations, n4 is 2;

[0071] In some embodiments, R5 and R6 may be the same or different, and are independently selected from hydrogen, C1-C8 alkyl groups substituted with or unsubstituted with one or more groups A;

[0072] Alternatively, R5 and R6 can form cycloalkyl groups with the C atoms they are attached to;

[0073] In some more specific implementations, both R5 and R6 are hydrogen;

[0074] In some embodiments, R5 is hydrogen, and R6 is selected from C1-C8 alkyl groups substituted or unsubstituted with one or more groups A;

[0075] In some more specific embodiments, R6 is selected from C1-C4 alkyl groups;

[0076] In some embodiments, R7 is hydrogen, halogen, amino, or a C1-C8 alkyl group substituted with or unsubstituted with one or more A groups;

[0077] In some more specific embodiments, the R7 mentioned above is selected from hydrogen and C1-C3 alkyl groups;

[0078] In some implementation schemes, Z is... in,

[0079] In some implementation schemes, n5 is selected from 0, 1, 2, 3, 4, and 5;

[0080] In some more specific implementations, n5 is preferably selected from 1, 2, and 3;

[0081] In some embodiments, R8 is selected from H, hydroxyl, and the following groups substituted or unsubstituted by one or more groups A: amino, C1-C8 alkyl, aryl, C1-C8 alkyloxy, alkylaryl, C1-C8 alkylcarbonyloxy;

[0082] In some more specific embodiments, the R8 is preferably derived from H, NO2, chlorine, bromine, or one or more of the following groups substituted or unsubstituted with group A: amino, C1-C3 alkyl, aryl, C1-C3 alkoxy, C1-C3 alkylcarbonyloxy.

[0083] In some implementations, the above-mentioned R e and R f Both are hydrogen.

[0084] In some implementations, the above-mentioned R e For hydrogen, R f The following groups are substituted or unsubstituted by one or more groups A: C1-C8 alkyl, C3-C8 cycloalkyl, heterocycloalkyl, C6-C18 aryl, heteroaryl, and non-aromatic heterocyclic groups; wherein,

[0085] In some more specific implementation schemes, the aforementioned R e For hydrogen, R f It is a C1-C8 alkyl group that is substituted or unsubstituted with one or more groups A.

[0086] In some implementations, the above-mentioned R e and R fAll are C1-C8 alkyl groups substituted or unsubstituted with one or more groups A; wherein,

[0087] In some more specific implementation schemes, the aforementioned R e and R f All are C1-C8 alkyl groups.

[0088] In some implementations, in equations (I) and / or (III) above, R3 and R4 are both Among them, Z, R5, R6, R7, R e R f n a n b n3 and n4 are as defined above.

[0089] In some embodiments, in formulas (I) and / or (IV) above, R3 is hydrogen and R4 is... Among them, Z, R5, R6, R7, R e R f n a n b n3 and n4 are as defined above.

[0090] In particular,

[0091] R X1 R X2 R X3 R X4 R X5 R X6 R X7 and R X8 It cannot be hydrogen at the same time;

[0092] When R1 and R2 are independently selected from hydroxyl, At the same time R x6 and R x7 When R is hydrogen or deuterium, respectively, X5 and R X8 It cannot be distinguished independently as hydrogen or deuterium.

[0093] The group A is: hydroxyl, carboxyl, amino, halogen, cyano, aldehyde, nitro, trifluoromethyl, C3-C8 cycloalkyl, C1-C8 alkoxy, chlorophenylcarbonyl.

[0094] In some embodiments, the novel cytidine derivative compounds provided by the present invention are selected from the following compounds:

[0095]

[0096]

[0097] On the other hand, in some embodiments, the present invention provides pharmaceutical compositions comprising the above-described novel cytidine derivative compounds, tautomers, stereoisomers, and pharmaceutically acceptable salts thereof.

[0098] In some embodiments, the present invention discloses a pharmaceutical composition comprising the active ingredient or main active ingredient of the compound, isomer or pharmaceutically acceptable salt thereof described in the present invention, supplemented by a pharmaceutically acceptable carrier.

[0099] In some embodiments, the novel cytidine derivative compounds of the present invention can be formulated as pharmaceutical compositions and administered to patients via a variety of suitable routes of administration, including systemic (e.g., oral or parenteral), intravenous, intramuscular, transdermal, or subcutaneous routes.

[0100] In another aspect, in some embodiments, the present invention provides that the above-mentioned novel cytidine derivative compounds, tautomers, stereoisomers, and pharmaceutically acceptable salts thereof, or pharmaceutical compositions, can be used against influenza viruses for the treatment and / or prevention of diseases caused by influenza viruses.

[0101] The compounds described in this invention exhibit better antiviral activity, lower cytotoxicity, and a higher selectivity index.

[0102] The compounds described in this invention have an inhibitory effect on viruses and inhibit viral proliferation.

[0103] The compounds described in this invention can be used as antiviral drugs with novel structures.

[0104] definition:

[0105] Unless otherwise stated, the following terms and phrases as used herein are intended to have the following meanings. A particular term or phrase should not be considered uncertain or unclear unless specifically defined, but should be understood in its ordinary sense. When a trade name appears herein, it is intended to refer to the corresponding product or its active ingredient.

[0106] Some compounds of this invention can exist in either a solvated or a solvent-based form, such as hydrates or ethanolates. Generally, the solvent-based and solvent-based forms are equivalent and both are included within the scope of this invention.

[0107] The term "pharmaceutical acceptable" refers to compounds, materials, compositions, and / or dosage forms that, within the bounds of reliable medical judgment, are suitable for use in contact with human and animal tissues without excessive toxicity, irritation, allergic reactions, or other problems or complications, in proportion to a reasonable benefit / risk ratio.

[0108] The term "pharmaceutically acceptable salt" refers to a salt of the compounds of this invention, prepared by reacting a compound with a relatively non-toxic acid or base, as discovered in this invention, with a specific substituent. When the compounds of this invention contain relatively acidic functional groups, base addition salts can be obtained by contacting a neutral form of such compound with a sufficient amount of base in a pure solution or a suitable inert solvent. Pharmaceutically acceptable base addition salts include aluminum, sodium, potassium, calcium, manganese, iron, ammonium, organic amine, or magnesium salts, or similar salts. When the compounds of this invention contain relatively basic functional groups, acid addition salts can be obtained by contacting a neutral form of such compound with a sufficient amount of acid in a pure solution or a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include inorganic acid salts, such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, bicarbonate, phosphoric acid, monohydrogen phosphate, dihydrogen phosphate, sulfuric acid, hydrogen sulfate, hydroiodic acid, phosphorous acid, etc.; and organic acid salts, such as acetic acid, propionic acid, isobutyric acid, maleic acid, malonic acid, benzoic acid, succinic acid, octanoic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, and methanesulfonic acid; as well as salts of amino acids (such as arginine) and salts of organic acids such as glucuronic acid. Certain specific compounds of the present invention contain both basic and acidic functional groups, and thus can be converted into either a base or an acid addition salt.

[0109] The term "alkyl" refers to a saturated aliphatic hydrocarbon group, including straight-chain and branched groups. Alkyl groups can be substituted or unsubstituted. When substituted, the substituent is preferably one or more, more preferably one to three, and most preferably one or two.

[0110] The term "alkenyl" refers to an aliphatic hydrocarbon group containing an unsaturated carbon-carbon double bond, including straight-chain and branched groups. The alkyl group can be substituted or unsubstituted. There can be one or more carbon-carbon double bonds.

[0111] The term "cycloalkyl" refers to a monocyclic or fused-ring group consisting entirely of carbon atoms (a "fused" ring means that each ring in the system shares a pair of adjacent carbon atoms with the other rings in the system), wherein one or more rings do not have a fully connected π-electron system. Examples of cycloalkyl groups (but not limited to) include cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, adamantane, cyclohexadiene, cycloheptane, and cyclohepttriene. Cycloalkyl groups can be substituted or unsubstituted.

[0112] The term "aryl" refers to an all-carbon monocyclic or fused polycyclic group with 1 to 12 carbon atoms and a fully conjugated π-electron system. Non-limiting examples of aryl groups include phenyl, naphthyl, and anthracene. Aryl groups can be substituted or unsubstituted. When substituted, the substituents are preferably one or more, more preferably one, two, or three, and even more preferably one or two.

[0113] The term "aryl hydrocarbon group" refers to a hydrocarbon group that has been replaced by an aryl group.

[0114] The term "heteroaryl" refers to a monocyclic or fused cyclic group of multiple atoms containing one, two, three, or four cyclic heteroatoms selected from N, O, or S, with the remaining cyclic atoms being C, and possessing a fully conjugated π-electron system. Non-limiting examples of unsubstituted heteroaryl groups include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyrimidine, quinoline, isoquinoline, purine, tetrazolium, triazine, and carbazole.

[0115] The term "alkoxy" refers to an alkyl group bonded to an oxygen atom, where the alkyl group can be straight-chain, branched, or cycloalkyl.

[0116] The term "hydroxyl group" refers to the -OH group.

[0117] The term "amino" refers to the -NH2 group.

[0118] The term "carboxyl group" refers to the -COOH group.

[0119] The term "halogen" refers to fluorine, chlorine, bromine, or iodine.

[0120] The term "pharmaceutically acceptable carrier" refers to any formulation or carrier medium capable of delivering an effective amount of the active substance of this invention without interfering with the biological activity of the active substance and without toxic side effects on the host or patient. Representative carriers include water, oil, vegetables and minerals, ointment bases, lotion bases, and ointment bases. These bases include suspending agents, thickeners, transdermal penetration enhancers, etc.

[0121] The term "stereoisomer" refers to compounds that have the same chemical composition but different spatial arrangements of atoms or groups.

[0122] The numerical range mentioned in this application, such as "C1-C8", means that the group can contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to 8 carbon atoms. Attached Figure Description

[0123] Figure 1 Results of lung virus titer test 1.

[0124] Figure 2 Result 2 of lung virus titer test. Detailed Implementation

[0125] The following examples provide numerous exemplary methods for preparing the compounds of the present invention. The invention is described in detail below through examples, but this does not imply any adverse limitation thereof. The invention has been described in detail herein, and specific embodiments thereof are also disclosed. It will be apparent to those skilled in the art that various changes and modifications can be made to the specific embodiments of the invention without departing from the spirit and scope thereof. Some compounds of the present invention can be used as intermediates for preparing other compounds of the present invention; the structures of all compounds have been determined by MS.

[0126] Unless otherwise specified, all materials used in the embodiments of this application were purchased commercially.

[0127] Comparative Example 1: Synthesis of Compound B

[0128] Reaction formula:

[0129]

[0130] Preparation method:

[0131] Step 1: Synthesis of compound B-02

[0132] Under nitrogen protection, compound B-SM1 (2.87 g, 10.0 mmol) and dichloromethane (150 mL) were added to a three-necked flask. The resulting solution was cooled to 0 °C, and 4-dimethylaminopyridine (DMAP, 0.14 g, 1.1 mmol) and imidazole (1.70 g, 25.0 mmol) were added sequentially. Tert-butyldimethylchlorosilane (TBSC1, 3.77 g, 25.0 mmol) was added over 10 minutes, and the resulting mixture was warmed to ambient temperature and stirred for 18 hours. Water was added to the system, and the mixture was stirred at room temperature for 2 hours. The mixture was separated, and the aqueous phase was extracted three times with dichloromethane. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography to give compound B-02 (3.37 g), in 65.3% yield. ESI-MS(+): m / z = 516.38.

[0133] Step 2: Synthesis of compound B-01

[0134] Compound B-02 (3.30 g, 6.4 mmol) and dichloromethane (80 mL) were added to a three-necked flask. The solution was cooled to 0 °C using an ice bath. DMAP (0.1 g, 0.82 mmol) and N,N-diisopropylethylamine (DIPEA, 4.14 g, 32.0 mmol) were added sequentially. 2,4,6-Triisopropylbenzene-1-sulfonyl chloride (3.88 g, 12.8 mmol) was slowly added to the flask. After the addition was complete, the flask was warmed to ambient temperature and stirred for 18 hours. The system was cooled to 0 °C, and N,N-diisopropylethylamine (3.31 g, 25.6 mmol) was added dropwise, followed immediately by solid hydroxylamine hydrochloride (1.78 g, 25.6 mmol). The mixture was warmed to room temperature and stirred for 3 hours. The reaction was quenched with water, and the resulting layer was separated. The aqueous layer was extracted with dichloromethane, and the combined organic matter was washed with brine, dried over sodium sulfate, concentrated under reduced pressure, and the residue was purified by column chromatography to give compound B-01 (2.08 g), yield 61.2%. ESI-MS(+): m / z = 531.42.

[0135] Step 3: Synthesis of Compound B

[0136] Compound B-01 (2.0 g, 3.8 mmol) and tetrahydrofuran (50 mL) were added to a three-necked flask, followed by triethylamine trihydrofluoride (0.61 g, 3.8 mmol). The mixture was stirred at ambient temperature for 18 hours. The mixture was concentrated under reduced pressure, and the residue was dissolved in a minimal amount of methanol. This solution was slowly added to dichloromethane with rapid stirring, and the mixture was stirred at room temperature for 15 minutes. The mixture was filtered and recrystallized from dichloromethane and petroleum ether to give compound B (0.72 g), in 62.6% yield. ESI-MS(+): m / z = 303.25.

[0137] Comparative Example 2: Synthesis of Compound C

[0138] Reaction formula:

[0139]

[0140] Preparation method:

[0141] Synthesis of compound C:

[0142] Compound C-SM1 (2.6 g, 10.0 mmol), hexamethyldisilazane (HMDS, 7.3 g, 45.0 mmol), and acetamide (1.8 g, 30.4 mmol) were added to a reaction flask. The mixture was heated to 120 °C and reacted for 24 h. The reaction was monitored by liquid chromatography-HPLC until the concentration of compound C-SM1 dropped below 1%. The reaction solution was cooled to room temperature, and methanol (10 mL) was slowly added. The mixture was filtered and then purified by column chromatography to give compound C (0.92 g), with a yield of 35.4%. ESI-MS (+): m / z = 260.55.

[0143] Comparative Example 3: Synthesis of Compound D

[0144] Reaction formula:

[0145]

[0146] Preparation method:

[0147] Step 1: Synthesis of compound D-02

[0148] Under nitrogen protection, compound C-SM1 (2.60 g, 10.0 mmol) and dichloromethane (150 mL) were added to a three-necked flask. The resulting solution was cooled to 0 °C, and 4-dimethylaminopyridine (DMAP, 0.14 g, 1.1 mmol) and imidazole (1.70 g, 25.0 mmol) were added sequentially. Tert-butyldimethylchlorosilane (TBSC1, 3.77 g, 25.0 mmol) was added over 10 minutes, and the resulting mixture was warmed to ambient temperature and stirred for 18 hours. Water was added to the system, and the mixture was stirred at room temperature for 2 hours. The mixture was separated, and the aqueous phase was extracted three times with dichloromethane. The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography to give compound D-02 (3.34 g), in 68.3% yield. ESI-MS(+): m / z = 489.61.

[0149] Step 2: Synthesis of compound D-01

[0150] Compound D-02 (3.13 g, 6.4 mmol) and dichloromethane (80 mL) were added to a three-necked flask. The solution was cooled to 0 °C using an ice bath. DMAP (0.1 g, 0.82 mmol) and N,N-diisopropylethylamine (DIPEA, 4.14 g, 32.0 mmol) were added sequentially. 2,4,6-Triisopropylbenzene-1-sulfonyl chloride (3.88 g, 12.8 mmol) was slowly added to the flask. After the addition was complete, the flask was warmed to ambient temperature and stirred for 18 hours. The system was cooled to 0 °C, and N,N-diisopropylethylamine (3.31 g, 25.6 mmol) was added dropwise, followed immediately by solid hydroxylamine hydrochloride (1.78 g, 25.6 mmol). The mixture was warmed to room temperature and stirred for 3 hours. The reaction was quenched with water, and the resulting layer was separated. The aqueous layer was extracted with dichloromethane, and the combined organic matter was washed with brine, dried over sodium sulfate, concentrated under reduced pressure, and the residue was purified by column chromatography to give compound D-01 (2.13 g), yield 66.1%. ESI-MS(+): m / z = 504.43.

[0151] Step 3: Synthesis of Compound D

[0152] Compound D-01 (1.91 g, 3.8 mmol) and tetrahydrofuran (50 mL) were added to a three-necked flask, followed by triethylamine trihydrofluoride (0.61 g, 3.8 mmol). The mixture was stirred at ambient temperature for 18 hours. The mixture was concentrated under reduced pressure, and the residue was dissolved in a minimal amount of methanol. This solution was slowly added to dichloromethane with rapid stirring, and the mixture was stirred at room temperature for 15 minutes. The mixture was filtered and recrystallized from dichloromethane and petroleum ether to give compound D (0.57 g), in 54.5% yield. ESI-MS(+): m / z = 276.38.

[0153] Example 1: Synthesis of compound DSC134-26

[0154] Reaction formula:

[0155]

[0156] Preparation method:

[0157] Compound SM3 was prepared using the method described in the European Journal of Medicinal Chemistry 46(2011)4178-4183.

[0158] Step 1: Preparation of compound DSC134-2602

[0159] Compound SM3 (10.6 g, 0.02 mol) and 25% ammonia / methanol (70 mL) were added sequentially to the reaction flask. The mixture was heated to 50-60 °C and reacted for 5 hours. The mixture was concentrated, and the residue was purified by column chromatography to obtain compound DSC134-2602 (3.87 g), with a yield of 67.4%. ESI-MS(+): m / z = 288.10.

[0160] Step 2: Preparation of compound DSC134-2601

[0161] Tetrahydrofuran (30 mL), DSC134-2602 (3.8 g, 13.2 mmol), and 4-dimethylaminopyridine (DMAP, 2.42 g, 19.8 mmol) were added sequentially to the reaction flask. After dissolution, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC, 2.46 g, 15.8 mmol) was added. The mixture was heated to 70 °C and stirred. The reaction was monitored by TLC until completion. The system was cooled and evaporated to dryness. The residue was added to ethyl acetate and water, and the organic phase was separated. The residue was washed twice with water, dried, evaporated to dryness under reduced pressure, and purified by column chromatography. Compound DSC134-2601 (1.61 g) was obtained, with a yield of 20.7%. ESI-MS (+): m / z = 588.10.

[0162] Step 3: Preparation of compound DSC134-26

[0163] Compound DSC134-2601 (1.6 g, 2.72 mmol), N,N-dimethylformamide (25 mL), and N,N-diisopropylethylamine (DIPEA, 0.70 g, 5.44 mmol) were added to a reaction flask and dissolved. Tripyrrylphosphonium hexafluorophosphate (PyBroP, 1.4 g, 3.0 mmol) was then added. The mixture was stirred at room temperature for 30 min, followed by the addition of hydroxylamine hydrochloride (0.23 g, 3.3 mmol). The reaction was carried out at 40–50 °C for 4–6 h. The reaction was monitored by TLC until completion. The mixture was cooled, water was added, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, washed twice with water, evaporated to dryness under reduced pressure, and the residue was subjected to column chromatography to obtain product DSC134-26 (0.31 g), with a yield of 18.9%. ESI-MS (+): m / z = 603.15.

[0164] Example 2: Synthesis of compound DSC134-28

[0165] Reaction formula:

[0166]

[0167] Preparation method:

[0168] Step 1: Preparation of compound DSC134-2802

[0169] Compound SM3 (3.60 g, 6.8 mmol) and dichloromethane (100 mL) were added to a reaction flask and stirred until cooled to 0 °C. Then, DMAP (0.83 g, 6.8 mmol) and DIPEA (4.41 g, 34.1 mmol) were added sequentially to the system. While stirring, 2,4,6-triisopropylbenzene-1-sulfonyl chloride (4.13 g, 13.6 mmol) was slowly added to the reaction flask. After the addition was complete, the mixture was stirred at room temperature for 18 hours. The system was cooled back to 0 °C, and DIPEA (3.51 g, 27.2 mmol) was added dropwise, followed immediately by solid hydroxylamine hydrochloride (1.9 g, 27.3 mmol). The mixture was warmed to room temperature and stirred for 3 hours. The reaction was quenched with water, and the mixture was separated. The aqueous layer was extracted twice with dichloromethane, and the organic phases were combined, washed with brine, dried over sodium sulfate, concentrated under reduced pressure, and the residue was purified by column chromatography to give compound DSC134-2802 (2.62 g), yield 70.6%. ESI-MS(+): m / z = 545.33.

[0170] Step 2: Preparation of compound DSC134-2801

[0171] Tetrahydrofuran (30 mL), DSC134-2802 (2.2 g, 4.0 mmol), and DMAP (0.73 g, 6.0 mmol) were added sequentially to the reaction flask. After dissolution, EDC (0.75 g, 4.8 mmol) was added. The mixture was heated to 70 °C and stirred. The reaction was monitored by TLC until completion. The system was cooled and evaporated to dryness. The residue was added to ethyl acetate and water, and the organic phase was separated. The residue was washed twice with water, dried, and evaporated to dryness under reduced pressure. The residue was purified by column chromatography to obtain product DSC134-2801 (2.3 g), with a yield of 68.0%. ESI-MS (+): m / z = 845.61.

[0172] Step 3: Preparation of compound DSC134-28

[0173] Compound DSC134-2801 (1.39 g, 1.64 mmol) and 25% ammonia / methanol (10 mL) were added sequentially to a reaction flask. The mixture was heated to 50-60°C and reacted for 5 hours. The mixture was concentrated, and the residue was purified by column chromatography to obtain compound DSC134-28 (0.42 g), with a yield of 42.5%. ESI-MS(+): m / z = 603.13.

[0174] Example 3: Synthesis of compound DSC134-31

[0175] Reaction formula:

[0176]

[0177] Preparation method:

[0178] Step 1: Preparation of compound DSC134-3101

[0179] Tetrahydrofuran (60 mL), SM4 (5.2 g, 20.0 mmol), and DMAP (3.67 g, 30.0 mmol) were added sequentially to the reaction flask. After dissolution, EDC (3.73 g, 24.0 mmol) was added. The mixture was heated to 70 °C and stirred. The reaction was monitored by TLC until completion. The system was cooled and evaporated to dryness. The residue was added to ethyl acetate and water, and the organic phase was separated. The residue was washed twice with water, dried, and evaporated to dryness under reduced pressure. The residue was purified by column chromatography. The compound was DSC134-3101 (2.63 g), with a yield of 23.4%. ESI-MS (+): m / z = 561.38.

[0180] Step 2: Preparation of compound DSC134-31

[0181] Compound DSC134-3101 (2.52 g, 4.50 mmol), N,N-dimethylformamide (45 mL), and DIPEA (1.16 g, 9.00 mmol) were added to a reaction flask and dissolved. Tripyrrylphosphonium hexafluorophosphate (PyBroP, 2.31 g, 4.95 mmol) was added, and the system was stirred at room temperature for 30 min. Hydroxylamine hydrochloride (0.38 g, 5.40 mmol) was then added, and the reaction was carried out at 40–50 °C for 4–6 h. The reaction was monitored by TLC until completion. The mixture was cooled, water was added, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, washed twice with water, evaporated under reduced pressure, and the residue was subjected to column chromatography to obtain product DSC134-31 (0.55 g), with a yield of 21.2%. ESI-MS (+): m / z = 576.15.

[0182] The compounds of the following examples were synthesized using the same method as in the above embodiments, either commercially available compounds or intermediate compounds appropriately synthesized from commercially available compounds.

[0183]

[0184]

[0185] Example 4: In vitro anti-influenza virus activity and cytotoxicity assay

[0186] Toxicity determination of the test compound to MDCK:

[0187] Take MDCK cell suspension in logarithmic growth phase (1×10⁻⁶) 5 100 μl of cells (cells / ml) was seeded into 96-well cell culture plates, with 1 × 10⁶ cells seeded per well. 4Cells were cultured in a 37°C, 5% CO2 incubator for 24 hours, then the DMEM medium containing 2% newborn calf serum was discarded. A series of drug-containing solutions diluted with the same medium were added, with a blank control group (no drug added). Each concentration was tested in triplicate. After 72 hours of drug treatment, the cytopathic effect (CPE) at each concentration was observed and recorded under a microscope ("0": no CPE, "1": CPE 1%–25%, "2": CPE 25%–50%, "3": CPE 50%–75%, "4": CPE 75%–100%). The half-maximal toxic concentration (MCC) of each drug was calculated using the Reed-Muench method. 50 ).

[0188] Assay for the anti-influenza virus activity of the test compound:

[0189] Take MDCK cell suspension in logarithmic growth phase (1×10⁻⁶) 5 100 μl of cells (cells / ml) was seeded into 96-well plates, with a cell count of 1 × 10⁶ cells per well. 4 Cells were cultured at 37°C in a 5% CO2 incubator. After 24 hours of culture, the DMEM medium containing 2% newborn calf serum was discarded, and virus solution (A / Hanfang / 359 / 95(H3N2)) (MOI = 0.1) was added to infect the cells. After 2 hours, the virus solution was discarded, and each well was washed twice with serum-free DMEM medium. Cells were then treated with a series of drug-containing solutions diluted with DMEM medium containing 2% newborn calf serum. A cell control group (cells only, without drug or virus) and a virus control group (cells and virus, without drug) were set up, with 3 replicates for each concentration. Cells were continued to be cultured at 37°C in a 5% CO2 incubator. Following drug administration, the degree of cytopathic effect (CPE) at each concentration was observed daily under a microscope. When the virus control group showed four plus signs for cytopathic effect, the results for each concentration were recorded ("0": no CPE; "1": CPE 1%–25%; "2": CPE 25%–50%; "3": CPE 50%–75%; "4": CPE 75%–100%). The antiviral half-maximal effective concentration (IC50) of each drug was calculated using the Reed-Muench method. 50 ), calculate the selection index (SI), the method for calculating SI is SI = TC 50 / IC 50 The results are shown in Table 1.

[0190] The structures of compounds A, B, C, D, and E are as follows:

[0191]

[0192] Table 1 Results of anti-H3N2 virus activity assay

[0193]

[0194]

[0195] A comparison of the IC50 data of compounds A and B, and of compounds C and D, indicates that adding a hydroxyl group to the nucleoside base produces a certain degree of enhancement in anti-influenza virus activity, but this effect is not significant. Compound E exhibits very poor anti-influenza virus activity. Unexpectedly, the IC50, TC50, and SI data of compounds A, B, E, and DSA134-26 in Group I, and compounds C, D, E, and DSA134-31 in Group II, show that attaching the 5-position hydroxyl group in the nucleoside sugar ring to the side chain of this invention significantly enhances anti-influenza virus activity with better safety and a higher selectivity index. Some compounds show an increase in anti-influenza virus activity and selectivity index of more than 34 times. The anti-influenza virus activity of other compounds of this invention is significantly better than that of the control compounds. These results suggest that the compounds disclosed in this invention can be used to treat influenza virus infection with lower dosage and fewer side effects.

[0196] Example 5: Lung Virus Titer Test

[0197] Forty female C57BL / 6J mice (6–8 weeks old, 18–20 g) were randomly divided into 8 groups of 5 mice each, designated as Group 1, Group 2, Group 3, Group 4, Group 5, Group 6, Group 7, and Group 8. Under anesthesia, the animals were inoculated intranasally with a median lethal dose (LD50) of influenza virus (H1N1, A / WSN / 33). Twenty-four hours after inoculation, each group received its corresponding drug. Group 1 (the solvent group) received 0.5% sodium carboxymethyl cellulose solution by gavage; Groups 2, 3, 4, 5, and 6 received equimolar doses of the control compounds by gavage (compound A: 15.06 mg / kg; compound B: 15.90 mg / kg; compound C: 13.64 mg / kg). The dosage of compound D was 14.48 mg / kg; the dosage of compound E was 16.77 mg / kg. Groups 7 and 8 were administered the test drugs DSC134-26 and DSC134-31 (equimolar amounts with the control compound, with DSC134-26 at a dosage of 31.72 mg / kg and DSC134-31 at a dosage of 30.30 mg / kg) by gavage, twice daily for 3 consecutive days. Four days after viral infection (3 days after administration), all animals were euthanized, and right lung tissue samples were collected, homogenized, and subjected to TCID45. 50 Virus titer determination. Virus titer results are as follows: Figure 1 and Figure 2 As shown.

[0198] The results of the lung virus titer test showed that, compared with the solvent group, the lung tissue virus titers of compounds DSC134-26, DSC134-31, control compound A, control compound B, control compound C, and control compound D were lower, while the lung tissue virus titer of control compound E showed no significant decrease. Compared with control compounds A, B, and E, and compared with control compounds C, D, and E, at equimolar doses, compounds DSC134-26 and DSC134-31 showed significantly lower virus titers, demonstrating superior anti-influenza virus efficacy.

[0199] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be defined by the claims.

Claims

1. A novel cytidine derivative compound as shown in (I) or a pharmaceutically acceptable salt thereof: In formula (I), R1 and R x6 Each element is independently selected from hydrogen, deuterium, hydroxyl group, and halogen. R2 and R x7 Each is independently selected from hydrogen, halogen, and C1-C8 alkyl groups; R3 and R4 may be the same or different, and are independently selected from hydrogen, or R3 and R4 cannot both be hydrogen; in, n a n and n4 are each independently selected from 0 or 1; n b n and n3 are each independently selected from 0, or 1, or 2, or 3, or 4, or 5; R5 and R6 may be the same or different, and are independently selected from hydrogen and C1-C8 alkyl groups; R7 is hydrogen or halogen; Z is selected from in, n5 is selected from 0, 1, 2, 3, 4, or 5; R8 is selected from H, hydroxyl, halogen, and the following groups substituted or unsubstituted by one or more groups A: amino, C1-C8 alkyl, aryl; R e and R f Each is independently selected from hydrogen and C1-C8 alkyl groups; R X1 R X2 R X3 R X4 R X5 It is hydrogen; R X8 Selected from hydrogen or azide groups; In particular, R X1 R X2 R X3 R X4 R X5 R X6 R X7 and R X8 It cannot be hydrogen at the same time; The group A is: hydroxyl, amino, or halogen.

2. The novel cytidine derivative compound as described in claim 1, or a pharmaceutically acceptable salt thereof, having the structure of formula (II): The substituents in formula (II) are defined as defined in formula (I) of claim 1.

3. The novel cytidine derivative compound as described in claim 1, or a pharmaceutically acceptable salt thereof, having the structure of formula (III): The substituents in formula (III) are defined as defined in formula (I) of claim 1.

4. The novel cytidine derivative compound as described in claim 1, or a pharmaceutically acceptable salt thereof, having the structure of formula (IV): The substituents in formula (IV) are defined as defined in formula (I) of claim 1.

5. The novel cytidine derivative compound or its pharmaceutically acceptable salt as described in any one of claims 1 to 4, selected from the following compounds: Or its pharmaceutically acceptable salt.

6. A pharmaceutical composition comprising any novel cytidine derivative compound or a pharmaceutically acceptable salt thereof as described in any one of claims 1 to 5.

7. The use of any novel cytidine derivative compound or a pharmaceutically acceptable salt thereof as described in any one of claims 1 to 5, or the use of the pharmaceutical composition of claim 6 in the preparation of an antiviral drug.

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