CN102232069B - N-acetylneuraminic acid compounds, pharmaceutical composition, preparation method and uses thereof - Google Patents

Abstract

The invention discloses an N-acetylneuraminic acid compound represented by the following general formula, its pharmaceutical composition, its preparation method and application. These compounds can inhibit influenza virus surface neuraminidase, and thus can be used for anti-influenza virus, especially for the treatment of influenza virus infection resistant to other anti-influenza drugs such as zanamivir and oseltamivir.

Description

N-acetylneuraminic acid compound, its pharmaceutical composition and its preparation method and application

technical field

The present invention relates to N-acetylneuraminic acid compound, its pharmaceutical composition and its preparation method and application. These compounds can inhibit virus surface neuraminidase, and thus can be applied to the treatment of related diseases.

Background technique

Neuraminidase exists on the surface of many influenza virus, parainfluenza virus, mumps virus and other virus particles. Because it can catalyze the cleavage of the α-ketoglycosidic bond between the terminal neuraminic acid and the adjacent sugar group, the receptor is destroyed, and the virion is released, thereby aggravating the symptoms of infection. Therefore, by inhibiting the activity of neuraminidase, progeny virus can be blocked from the surface of infected cells, thereby preventing secondary infection. Therefore, it is generally believed that substances with neuraminidase inhibitory activity can be used to treat or prevent influenza.

Most known neuraminidase inhibitors are analogs of neuraminic acid, such as 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (DANA) and its derivatives. International patent application WO91/16320 describes a series of DANA derivatives which have certain inhibitory activity on neuraminidase both in vivo and in vitro. Other DANA derivatives are disclosed in WO98/06712, WO97/06157, WO01/81331 and other international patent applications. Zanamivir is the first neuraminidase inhibitor listed on the market. However, due to the high polarity of the compound, its oral bioavailability is very low (2-3%), and it cannot be administered orally and needs to be made into a spray Drugs are administered through nasal cavity inhalation, which brings great inconvenience to patients and increases the production cost of the preparations. On the other hand, influenza viruses are prone to develop drug resistance to marketed drugs such as zanamivir and oseltamivir. Therefore, it is extremely urgent to find new active compounds and develop new anti-influenza drugs. In the process of searching for new active compounds with inhibitory effect on influenza virus, the present inventors discovered a class of N-acetylneuraminic acid compounds with novel structure and obvious anti-influenza virus activity.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a novel class of N-acetylneuraminic acid compounds or any prodrug form thereof, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates for inhibiting viruses, especially influenza virus .

Another object of the present invention is to provide a preparation method of the N-acetylneuraminic acid compounds or any of their prodrug forms, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates.

Another object of the present invention is to provide an antiviral pharmaceutical composition that can effectively inhibit neuraminidase.

Another object of the present invention is to provide the above-mentioned N-acetylneuraminic acid compounds or any prodrug forms thereof, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates and pharmaceutical compositions. Amino acid compounds or any of their prodrug forms, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates and pharmaceutical compositions thereof can effectively inhibit neuraminidase, and thus are neuraminidase inhibitors, which can be applied to Related viral diseases and treatment of their infections.

According to one aspect of the present invention, the present invention provides N-acetylneuraminic acid compounds represented by the following general formula (I) or any of their prodrug forms, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates:

in:

R ¹ represents OR ⁵ , SR ⁵ , NR ⁵ R ⁶ , N(OR ⁵ )R ⁶ or N(NR ⁵ R ⁶ )R ⁶ ;

R ² represents H, C _1-20 alkyl, C _1-5 alkoxy substituted C _1-5 alkyl, COR ⁵ or CONR ⁵ R ⁶ ;

R ³ represents N ₃ , NR ⁷ R ⁸ , NHC (=NR ⁹ )NR ⁵ R ¹⁰ , N=PPh ₃ or

R ⁴ represents COOR ⁵ , CONR ⁵ R ⁶ or CON(OR ⁵ )R ⁶ ;

R ⁵ represents H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, pentafluorophenyl, aryl, CONR ¹⁴ R ¹⁵ , COOR ¹⁴ , COR ¹⁴ , a five- or six-membered monosaccharide group optionally substituted by one or more hydroxyl protecting groups, or a C _1-10 alkyl group, C _3-8 cycloalkyl group substituted by one or more of the following groups, C _3-10 alkenyl or C _3-10 alkynyl: NR ¹⁴ R ¹⁵ , NR ¹⁴ COR ¹⁵ , CO ₂ R ¹⁴ , OR ¹⁴ , C _3-8 cycloalkyl and aryl;

R ⁶ represents H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, aryl, COR ¹⁴ , optionally protected by one or more hydroxyl groups A five- or six-membered monosaccharide group substituted by a group or a C _1-10 alkyl group substituted by one or more of the following groups: NR ¹⁴ R ¹⁴ , COR ¹⁴ , C _3-8 cycloalkyl, CN, N ₃ , OR ¹⁴ and aryl;

Or R ⁵ and R ⁶ and their connected nitrogen atoms together form a ring structure, the ring structure can be saturated or unsaturated, and can contain one or more heteroatoms selected from N, O and S, the The ring structure can also optionally be replaced by halogen, C _1-10 alkyl, C ₁ - _{C 10} alkoxy, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, CF _3. Substituted by CN or NO ₂ ;

R ⁷ and R ⁸ each independently represent H, CN, C _1-6 alkyl, C _3-8 cycloalkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _2-6 hydrocarbon chain, The hydrocarbon chain optionally contains an NR ¹¹ group, and the hydrocarbon chain is optionally substituted by 1 to 4 groups selected from oxo (carbonyl) and C _1-6 alkyl, and the C _{1 -6} alkyl is optionally substituted with hydroxy or aryl;

R ⁹ and R ¹⁰ each independently represent H, C _1-6 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, NR ¹⁴ R ¹⁵ , OR ¹⁴ , CN or NO ₂ ;

R ¹¹ and R ¹² each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, C _1-10 alkoxy, COOR ⁵ , CONR ¹⁴ R ¹⁵ or aryl; or C _1-10 alkyl optionally substituted by hydroxyl, amino, amino, COOR ⁵ or C _1-6 alkoxy;

R ¹⁴ and R ¹⁵ each independently represent H, C _1-6 alkyl, C _3-8 cycloalkyl or aryl;

Wherein, the aryl refers to an aromatic carbocyclic or heterocyclic group, which is optionally substituted. When the aryl is substituted, suitable substituents include C _1-4 alkyl, C _1-4 alkoxy, halogen, nitro, trifluoromethyl, amino, C _1-4 alkyl substituted amino , phenyl and benzyl. Suitably, the aryl group is substituted with 1 to 3 of the above substituents.

Herein, the alkyl group includes linear or branched saturated hydrocarbon groups.

Herein, alkenyl refers to a linear or branched hydrocarbon group containing one or more carbon-carbon double bonds.

Herein, alkynyl refers to a straight-chain or branched hydrocarbon group containing one or more carbon-carbon triple bonds.

In the above definitions, the compounds of general formula (I) may contain one or more chiral centers and thus may exist as stereoisomers, ie enantiomers or diastereomers, or mixtures thereof. The compounds of the present invention may be individual stereoisomers or mixtures of individual stereoisomers of the compound of general formula (I). Diastereoisomers may be separated by conventional techniques, for example, by fractional crystallization or chromatography (including HPLC) of diastereomeric mixtures of compounds of general formula (I) or suitable salts or derivatives thereof. separate. The single enantiomers of general formula (I) can also be prepared from corresponding optically pure intermediates or by resolution, which can be separated by chiral columns, or by reacting with optically active acids or bases to form diastereomeric enantiomers. The isomeric salts crystallize in fractional steps.

The pharmaceutically acceptable salt of the compound represented by the general formula (I) of the present invention refers to the salt formed by the compound represented by the general formula (I) and a suitable acid or base according to the conventional chemical salt-forming method, such as a suitable Examples of acids include hydrochloric acid, hydrobromic acid, sulfuric acid, perchloric acid, fumaric acid, maleic acid, phosphoric acid, glycolic acid, lactic acid, salicylic acid, succinic acid, p-toluenesulfonic acid, tartaric acid, acetic acid, tris Fluoroacetic acid, citric acid, methanesulfonic acid, formic acid, benzoic acid, malonic acid, naphthalene-2-sulfonic acid and benzenesulfonic acid, other acids such as oxalic acid, although not themselves pharmaceutically acceptable, are used in the preparation of Salts of intermediates, which are used to prepare compounds of the present invention and pharmaceutically acceptable acid addition salts thereof; salts formed with bases, such as alkali metals (such as sodium) of compounds represented by general formula (I), Salts of alkaline earth metals (eg magnesium), ammonium or NR ⁴⁺ (wherein R is C _1-4 alkyl).

Preferably, in the compound of formula (I):

R ¹ represents OR ⁵ , NR ⁵ R ⁶ or N(OR ⁵ )R ⁶ ;

R ² represents H, COR ⁵ or CONR ⁵ R ⁶ ;

R ³ represents NR ⁷ R ⁸ , NHC (=NR ⁹ ) NR ⁵ R ¹⁰ or It is in alpha configuration;

R ⁴ represents COOR ⁵ , CONR ⁵ R ⁶ or CON(OR ⁵ )R ⁶ ;

R ⁵ and R ⁶ each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, aryl or optionally replaced by one or more A five-membered or six-membered monosaccharide group substituted by substituents selected from C ₁ -C ₆ alkyl, trimethylsilyl, benzyl and acetyl; or by OR ¹⁴ , C _3-8 cycloalkyl or Aryl substituted C _1-10 alkyl, C _3-8 cycloalkyl, C _3-10 alkenyl or C _3-10 alkynyl;

Or R ⁵ and R ⁶ and their connected nitrogen atoms together form a ring structure, the ring structure can be saturated or unsaturated, and can contain one or more heteroatoms selected from N, O and S, the The ring structure can also optionally be substituted by halogen, C _1-10 alkyl, C ₁ - _{C 10} alkoxy, C _3-8 cycloalkyl, C _2-10 alkenyl or C _2-10 alkynyl;

R ⁷ and R ⁸ each independently represent H, CN, C _1-6 alkyl, C _3-8 cycloalkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _2-6 hydrocarbon chain, The hydrocarbon chain optionally contains an NR ¹¹ group, and the hydrocarbon chain is optionally substituted by 1 to 4 groups selected from oxo (carbonyl) and C _1-6 alkyl, and the C _{1 -6} alkyl is optionally substituted with hydroxy or aryl;

R ⁹ and R ¹⁰ each independently represent H, C _1-6 alkyl, NR ¹⁴ R ¹⁵ , OR ¹⁴ , CN or NO ₂ ;

R ¹¹ and R ¹² each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, COOR ⁵ or aryl; or optionally replaced by hydroxyl, amino, amino, COOR ⁵ or C _1- C _1-10 alkyl substituted by ₆ alkoxy groups;

R ¹⁴ and R ¹⁵ each independently represent H, C _1-6 alkyl, C _3-8 cycloalkyl or aryl;

Wherein, the definition of the aryl group is the same as above.

More preferably, in the compound of formula (I):

R ¹ represents NR ⁵ R ⁶ or N(OR ⁵ )R ⁶ ;

R ² represents H or COR ⁵ ;

R ³ is α configuration;

R ³ represents NR ⁷ R ⁸ or NHC (=NR ⁹ ) NR ⁵ R ¹⁰ ;

R ⁴ represents COOR ⁵ or CON(OR ⁵ )R ⁶ ;

R ⁵ and R ⁶ independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, rhamnosyl, mannosyl, glucose group, C _1-10 alkyl substituted by hydroxy, C _3-8 cycloalkyl substituted by hydroxy, C _3-10 alkenyl substituted by hydroxy or C _3-10 alkynyl substituted by hydroxy; or R ⁵ and R ⁶ together with their connected nitrogen atoms form a ring structure, the ring structure can be saturated or unsaturated, and can contain one or more heteroatoms selected from N, O and S, the ring structure also Can be optionally substituted by C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl or C _2-10 alkynyl;

R ⁷ and R ⁸ each independently represent H, CN, C _1-6 alkyl, C _3-8 cycloalkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _2-6 hydrocarbon chain, An NR ¹¹ group is optionally contained in the hydrocarbon chain, and the hydrocarbon chain is optionally substituted by 1 or 2 groups selected from oxo (carbonyl) and C _1-6 alkyl, and the C _{1 -6} alkyl is optionally substituted by hydroxyl or aryl, said aryl includes phenyl, naphthyl, pyridyl, imidazolyl and thienyl, and is optionally substituted; when said aryl is substituted, The substituents include C _1-4 alkyl, C _1-4 alkoxy, nitro, amino, phenyl and benzyl; and the substituted aryl has 1 to 3 of the above substituents;

R ⁹ and R ¹⁰ each independently represent H, C _1-6 alkyl, NH ₂ , OH, CN or NO ₂ ;

R ¹¹ and R ¹² each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl or COOR ⁵ .

Further preferred compounds are shown in formula (I):

R ¹ represents NR ⁵ R ⁶ ;

^R2 represents H;

R ³ represents NH ₂ or NHC(=NH)NH ₂ , which is in α configuration;

R ⁴ represents COOR ⁵ ;

R ⁵ and R ⁶ each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, mannosyl, glucosyl or substituted by hydroxyl C _1-10 alkyl; or R ⁵ and R ⁶ together with their connected nitrogen atoms form a ring structure, the ring structure can be saturated or unsaturated, and can contain one or more selected from N, O and heteroatoms in S, the ring structure can also be optionally substituted by C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl or C _2-10 alkynyl. For example, the ring structure may be morpholinyl, thiomorpholinyl, piperazinyl and the like.

Particularly preferred specific compounds of the invention include:

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-methylamino-2'-oxyethyl]-4-amino-3,4-di Hydropyran-6-carboxylic acid (Example 22 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-methylamino-2'-oxyethyl]-4-guanidino-3,4- Dihydropyran-6-carboxylic acid (Example 23 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-dimethylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid (Example 24 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-dimethylamino-2'-oxyethyl]-4-guanidino-3,4 -dihydropyran-6-carboxylic acid (compound of Example 25),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-ethylamino-2'-oxyethyl]-4-amino-3,4 - methyl dihydropyran-6-carboxylate (compound of Example 27),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-ethylamino-2'-oxyethyl]-4-amino-3,4-di Hydropyran-6-carboxylic acid (Example 28 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-ethylamino-2'-oxyethyl]-4-guanidino-3,4- Dihydropyran-6-carboxylic acid (Example 30 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-diethylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid (compound of Example 31),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-diethylamino-2'-oxyethyl]-4-amino-3, 4-dihydropyran-6-carboxylic acid methyl ester (Example 32 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-diethylamino-2'-oxyethyl]-4-guanidino-3 , methyl 4-dihydropyran-6-carboxylate (Example 34 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-diethylamino-2'-oxyethyl]-4-guanidino-3,4 -dihydropyran-6-carboxylic acid (compound of Example 35),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-cyclopentylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid (Example 36 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-cyclopentylamino-2'-oxyethyl]-4-guanidino-3,4 -dihydropyran-6-carboxylic acid (compound of Example 37),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-amino-2'-oxyethyl]-4-amino-3,4-dihydropyridine Fran-6-carboxylic acid (compound of Example 42),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-isopropylamino-2'-oxyethyl]-4-amino-3,4-di Hydropyran-6-carboxylic acid (Example 43 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-hydroxylamino-2'-oxyethyl]-4-amino-3,4-dihydro Pyran-6-carboxylic acid (Example 44 compound),

(2R,3R,4S)-3-Acetamido-2-[(S)-1'-hydroxy-2'-cyclohexylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid (Example 45 compound),

(2R,3R,4S)-3-Acetamido-2-[(S)-1'-hydroxy-2'-cyclohexylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid (Example 47 compound),

(2R,3R,4S)-3-Acetamido-2-[(S)-1'-hydroxy-2'-amino-2'-oxyethyl]-4-guanidino-3,4-dihydro Pyran-6-carboxylic acid (Example 48 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-isopropylamino-2'-oxyethyl]-4-guanidino-3,4 -dihydropyran-6-carboxylic acid (compound of Example 49),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-di(hydroxyethyl)amino-2'-oxyethyl]-4-amino- 3,4-dihydropyran-6-carboxylic acid (compound of Example 116),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-di(hydroxyethyl)amino-2'-oxyethyl]-4-guanidino -3,4-dihydropyran-6-carboxylic acid,

(2R,3R,4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-hydroxyethylamino-2'-oxyethyl]-4-amino-3,4 -dihydropyran-6-carboxylic acid (compound of Example 117),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-hydroxyethylamino-2'-oxyethyl]-4-guanidino-3, 4-dihydropyran-6-carboxylic acid (compound of Example 120),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-morpholinyl-2'-oxyethyl]-4-amino-3,4-di Hydropyran-6-carboxylic acid (Example 118 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-morpholinyl-2'-oxyethyl]-4-amino-3,4-di Methyl hydropyran-6-carboxylate (Example 121 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-morpholinyl-2'-oxyethyl]-4-guanidino-3,4- Dihydropyran-6-carboxylic acid (Example 123 compound),

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-(tetrahydro-2,4,5-trihydroxy-6-(hydroxymethyl)- 2H-pyran-3-ylamino)-2'-oxyethyl]-4-amino-3,4-dihydropyran-6-carboxylic acid (Example 119 compound), and

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-(tetrahydro-2,4,5-trihydroxy-6-(hydroxymethyl)- 2H-pyran-3-ylamino)-2'-oxyethyl]-4-guanidino-3,4-dihydropyran-6-carboxylic acid.

Further particularly preferred specific compounds of the present invention include:

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-dimethylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-dimethylamino-2'-oxyethyl]-4-guanidino-3,4 -Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-diethylamino-2'-oxyethyl]-4-amino-3,4- Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-diethylamino-2'-oxyethyl]-4-guanidino-3,4 -Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-cyclopentylamino-2'-oxyethyl]-4-guanidino-3,4 -Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-di(hydroxyethyl)amino-2'-oxyethyl]-4-amino- 3,4-dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-di(hydroxyethyl)amino-2'-oxyethyl]-4-guanidino -3,4-dihydropyran-6-carboxylic acid,

(2R,3R,4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-hydroxyethylamino-2'-oxyethyl]-4-amino-3,4 -Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-hydroxyethylamino-2'-oxyethyl]-4-guanidino-3, 4-dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-morpholinyl-2'-oxyethyl]-4-amino-3,4-di Hydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-morpholinyl-2'-oxyethyl]-4-guanidino-3,4- Dihydropyran-6-carboxylic acid,

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-(tetrahydro-2,4,5-trihydroxy-6-(hydroxymethyl)- 2H-pyran-3-ylamino)-2'-oxyethyl]-4-amino-3,4-dihydropyran-6-carboxylic acid, and

(2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxy-2'-(tetrahydro-2,4,5-trihydroxy-6-(hydroxymethyl)- 2H-pyran-3-ylamino)-2'-oxyethyl]-4-guanidino-3,4-dihydropyran-6-carboxylic acid.

According to another aspect of the present invention, the present invention provides a preparation method of N-acetylneuraminic acid compounds represented by general formula (I) or any of their prodrug forms, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates , the method includes any of the following methods:

(1) When R ¹ is OH in the compound of general formula (I), R ² is not H, R ³ is N ₃ , R ⁴ is COOR ⁵ , and R ⁵ is not H, the compound of general formula (Ia), Can be prepared by oxidative cleavage of compounds of general formula (II) (Carbohydrate Research, 2008, 343, 14, 2459-2462.), followed by deprotection if necessary, the ^R2 and ^R4 substituents of compounds of general formula (II) Definition is the same as the compound of general formula (I):

Oxidative cleavage is suitably accomplished in two steps. Suitably the first step is carried out with a periodate, such as sodium periodate, suitably in a suitable solvent, such as an aqueous organic solvent, eg aqueous methanol. A suitable reagent for the second step of oxidative cleavage may be a chlorite, such as sodium chlorite, suitably in the presence of a buffer, such as an alkali metal or alkaline earth metal phosphate, such as potassium dihydrogen phosphate, and in aqueous organic In solvents such as aqueous mixtures of alcohols and hydrocarbons, for example aqueous mixtures of tert-butanol and cyclohexene.

(2) When ^R in the compound of the general formula (I) is OR ⁵ or SR ⁵ , that is, the compound of the general formula (Ic), it can be obtained by the corresponding compound of the general formula (Ib) ( ^R in the compound of the general formula (I) Represents OH) and is prepared by condensation reaction of an oxygen-containing or sulfur-containing compound substituted by ^R :

(3) When R ¹ in the compound of general formula (I) is NR ⁵ R ⁶ , N(OR ⁵ )R ⁶ or N(NR ⁵ R ⁶ )R ⁶ , the compound of general formula (Id) can be passed through the corresponding The compound of general formula (Ib) (R ¹ in the compound of general formula (I) represents OH) reacts with nitrogen-containing compounds substituted by -R ⁵ R ⁶ , -(OR ⁵ )R ⁶ or -(NR ⁵ R ⁶ )R ⁶ to prepare. Suitably, the carboxyl group is activated prior to reaction with the amine. Suitable activation methods will be clear to those skilled in the art and include, for example, conversion to pentafluorophenoxy. The amination reaction may conveniently be carried out in a suitable organic solvent, such as ether, for example in THF.

(4) When ^R in the compound of general formula (I) is When, that is, the compound of general formula (If) can be prepared by reacting the corresponding compound of general formula (Ie) (R ³ in the compound of general formula (I) represents N ₃ ) with an alkyne compound substituted by R ¹¹ and R ¹² . Suitably, the preparation takes place under the catalysis of a catalyst. Suitable catalytic methods will be clear to those skilled in the art, such as cuprous ion catalysis.

(5) When R ³ in the compound of general formula (I) is NH ₂ , that is, the compound of general formula (Ig), it can be obtained by the corresponding compound of general formula (Ie) (R ³ in the compound of general formula (I) represents N ₃ ) is prepared by reduction of the azido group:

The reduction can be accomplished by any known method for converting azides to amines. Suitable methods are described in the Examples below, and are described, for example, in International Patent Application Publications WO 93/12105 and WO 95/00503. It is suitable to use Lindlar catalyst to catalyze, hydrogen or formic acid and other compounds that can provide active hydrogen are reduced to complete the reaction.

(6) When R ³ in the compound of general formula (I) is NR ⁷ R ⁸ , that is, the compound of general formula (Ih), it can be obtained from the compound of general formula (Ig) (R ³ in the compound of general formula (I) is NH ₂ ) is prepared by reacting a compound substituted by R ⁷ and R ⁸ , for example by conventional N-functionalization reaction with halides, acid anhydrides, acyl halide derivatives, etc. containing R ⁷ and R ⁸ substituents, but not limited to this. Suitable methods of preparation will be clear to those skilled in the art.

(7) When R ³ in the compound of the general formula (I) is NHC (=NR ¹⁴ ) NR ¹⁵ R ¹⁶ , that is, the compound of the general formula (Ii), it can be obtained from the compound of the general formula (Ih) (the compound of the general formula (I) R ³ is NR ⁷ R ⁸ ) prepared by guanidinylation. Appropriate methods for introducing guanidino groups and derivatives thereof will be clear to those skilled in the art. Especially when R ³ in the compound of general formula (I) is NHC (=NH) NH ₂ When, that is, the compound of general formula (Ik), for example by the compound of general formula (Ig) (R ³ in the compound of general formula (I) is NH ₂ ) is prepared by reacting with amidinopyrazole or its salt or derivative (preferably amidinopyrazole) or via an intermediate compound of formula (Ij) (R ³ in the compound of general formula (I) is NHCN).

(8) When R ³ represents N ₃ in the compound of general formula (I), and R ⁴ is CONR ⁵ R ⁶ , that is, the compound of general formula (Im) can be obtained by the corresponding compound of general formula (I1) (general formula (I) R ³ in the compound represents N ₃ , R ⁴ is COOR ⁵ , and R ⁵ is not H) obtained by reacting with a basic salt of hydroxylamine or its derivatives. Suitable transformation methods will be clear to those skilled in the art and include, for example, the use of _NH2OH /KOH.

(9) Compounds of general formula (Ih) (wherein R ³ is NR ⁷ R ⁸ ) or compounds of general formula (Ii) (wherein R ³ is NHC (=NR ¹⁴ ) NR ¹⁵ R ¹⁶ ) can also be obtained from general formula (Im) The compound (R ³ in the compound of general formula (I) represents N ₃ , and R ⁴ is CONR ⁵ R ⁶ ) is prepared by reducing the azido group similarly to the method (5) above, and then further reacting. Suitable methods of preparation will be clear to those skilled in the art.

(10) Other compounds of general formula (I) can be prepared by mutual conversion of functional groups between different compounds of general formula (I). For example, compounds wherein ^R2 is H can be prepared from compounds other than H; compounds where ^R7 and ^R8 are not H can be prepared from corresponding compounds where ^R7 and/or ^R8 are H; ^R4 is Compounds in which COOR ⁵ , CONR ⁵ R ⁶ or CON(OR ⁵ )R ⁶ can be interconverted with compounds in which R ⁴ is COOH.

Those skilled in the art will understand that, in order to prevent side reactions, it may be necessary to protect one or more sensitive groups in the molecule at any stage of the above method; the protective group can be removed at any appropriate subsequent stage of the reaction sequence.

Protective groups for the preparation of compounds of general formula (I) can use conventional methods. See for example "Greene's protective groups in organic synthesis", Peter G.M. Wuts and Theodora W. Greene (A John Wiley & Sons, Inc., 2007).

Traditional amino protecting groups may include, for example, aralkyl groups such as benzyl, diphenylmethyl or triphenylmethyl; and acyl groups such as N-benzyloxycarbonyl or tert-butoxycarbonyl.

Hydroxyl groups can be protected by: aralkyl groups such as benzyl, diphenylmethyl or triphenylmethyl; acyl groups such as acetyl; silicon protecting groups such as trimethylsilyl, or As a tetrahydrofuran derivative.

Carboxylic acid groups can be suitably protected as methyl or diphenylmethyl esters.

Any protecting groups present may be removed by conventional methods.

When it is desired to isolate a compound of the invention in the form of a salt, eg an acid addition salt, this can be accomplished by treating the free base of general formula (I) with an appropriate acid, preferably using an equivalent amount of acid.

According to another aspect of the present invention, the pharmaceutical composition of the present invention contains a therapeutically effective amount of one or more N-acetylneuraminic acid compounds represented by the above general formula (I) or any prodrug form thereof, their A pharmaceutically acceptable salt or a pharmaceutically acceptable solvate, and one or more pharmaceutically acceptable carriers or diluents.

According to another aspect of the present invention, the compound of general formula (I) can be used as a prodrug, so as to increase the bioavailability or improve the physicochemical properties of the compound. For example, in the compound of general formula (I), the compound in which R ⁴ represents COOR ⁵ (R ⁵ is not H) can also be used as a prodrug form of the compound in which R ⁴ represents COOH. The polarity of the compound is reduced, which facilitates oral administration to patients.

The N-acetylneuraminic acid compounds of the present invention or any of their prodrug forms, their pharmaceutically acceptable salts or pharmaceutically acceptable solvates and pharmaceutical compositions thereof can effectively inhibit neuraminidase, and thus can be applied to related disease treatment.

Due to the high variability of influenza viruses, the existing neuraminidase inhibitors have gradually developed drug resistance. The present invention is a new compound with neuraminidase inhibitory activity and anti-influenza virus activity in vivo, and It has predictable high bioavailability, which provides possible candidate drugs and more choices for the prevention and treatment of influenza.

Detailed ways

The following examples further illustrate the synthesis of the compounds of the present invention and their intermediates, but do not limit the scope of the present invention.

¹ H NMR was performed on a Mercury-400 nuclear magnetic resonance spectrometer (Varian Company), and the observation frequency of ¹ H NMR was 300 MHz or 400 MHz. Conventional abbreviations are as follows: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet. Mass spectrometry was performed on a MAT-95 mass spectrometer (Thermo Finnigan Company), with an ionization mode of EI 70V, a source temperature of 200°C, and an LR resolution of 1000. High-resolution mass spectra were determined by Finnigan MAT, Bruker Daltonics FTMS-7 instruments.

Example 1 (S)-[(2R,3R,4S)-3-acetamido-4-azido-6-(methoxycarbonyl-3,4-dihydropyran-2']-2- Acetoxyacetic acid

7-O-acetyl-N-acetyl-2,4-dideoxy-2,3-dehydro-4α-azido-D-neuraminic acid methyl ester (1.6 g, 4.3 mmol) (Carbohydrate Research, 2008, 343, 12, 2459-2462.) was dissolved in a mixed solution of CH ₃ OH and H ₂ O (48 mL and 16 mL), added NaIO ₄ (1.84 g, 8.6 mmol, 2.0 eq.), and stirred at room temperature for 30 min, Filter and concentrate under reduced pressure to obtain a white solid. The white solid was dissolved in t-BuOH (27mL), cyclohexene (2.7mL,) was added, and then NaClO ₂ (2.87g,), KH ₂ PO ₄ (2.87g,) in water (18.5 mL) solution. The solution changed from colorless to bright orange, and after stirring at room temperature for 2 h, the reaction stopped. Add ethyl acetate (50mL) and H ₂ O (100mL) to the reaction solution, separate the layers, discard the ethyl acetate layer, and adjust the pH of the aqueous layer to 1-2 with 6M HCl solution, then extract with ethyl acetate (75mL ×5), the organic phases were combined, dried over anhydrous MgSO ₄ , filtered, and concentrated under reduced pressure to obtain 1.765 g of the title compound as a white solid, yield: 100%.

¹ H NMR (300MHz, DMSO): δ8.19 (1H, d, J = 9.3Hz, NH), 5.89 (1H, d, J = 2.5Hz, 3-H), 5.22 (1H, d, J = 2.1 Hz, 7-H), 4.56 (1H, dd, J=2.1Hz, J=10.9Hz, 6-H), 4.43 (1H, dd, J=2.3Hz, J=9.4Hz, 4-H), 4.07 (1H, d, J=10.5Hz, 5-H), 3.71 (3H, s, CH ₃ ), 2.05 (3H, s, OAc), 1.79 (3H, s, NAc); HRMS (ESI): m/ z _Calcd : _C13H16N4O8 [M+H] ⁺ _357.1 . Found _: 356.3.

Example 2 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-pentafluorophenoxy-2'-oxyethyl]-4- Azido-3,4-dihydropyran-6-carboxylic acid methyl ester

Dissolve the compound of Example 1 (855mg, 2.4mmol) in DMF (8mL), then add pyridine (0.2mL, 2.5mmol, 1.1eq.) and CF ₃ COOC ₆ F ₅ (1.11mL, 0.63g/mL, 2.5 mmol, 1.1eq.), after stirring at room temperature for 2h, stop the reaction. Ethyl acetate (32mL) was added to the reaction solution, washed successively with 1M HCl (30mL×3), saturated NaHCO ₃ (30mL×3), saturated NaCl solution (30mL×1), dried over anhydrous MgSO ₄ , filtered, Concentrate under reduced pressure until a solid precipitates, and add petroleum ether dropwise to crystallize to obtain 523 mg of the title compound, yield: 42%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.05 (1H, d, J = 2.6Hz, 3-H), 5.78 (1H, d, J = 2.7Hz, 7-H), 5.61 (1H, d, J=8.7Hz, NH), 4.99(1H, dd, J=2.6Hz, J=10.4Hz, 6-H), 4.47(1H,dd, J=2.7Hz, J=9.2Hz, 4-H), 4.09 (1H, dd, J = 9.1 Hz, J = 19.0 Hz, 5-H), 3.81 (3H, s, _CH3 ), 2.27 (3H, s, OAc), 2.06 (3H, s, NAc); LRMS (ESI): m/z [M+H] ⁺ = 544.9.

Example 3 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-methylamino-2'-oxyethyl]-4-azide Methyl-3,4-dihydropyran-6-carboxylate

The compound of Example 1 (35 mg, 0.1 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI) (21 mg, 0.11 mmol) were dissolved in THF (0.5 mL), 1-Hydroxybenzotriazole (HOBt) (15 mg, 0.11 mmol) was added under ice-water cooling, and after stirring at room temperature for 10 min, an aqueous solution of methylamine (12 μL, 0.11 mmol) was added. After 2.5 h, TLC showed that the reaction was complete, and the reaction was stopped. . Concentrate to dryness under reduced pressure, and separate by column chromatography (CH ₂ Cl ₂ :CH ₃ OH=60:1 (v/v)) to obtain 27 mg of the title compound as a white solid, yield: 75%.

¹ H NMR (400MHz, CDCl ₃ ): δ7.26 (1H, d, J = 8.9Hz, NHCO), 6.49 (1H, d, J = 4.7Hz, NH), 5.91 (1H, d, J = 2.2Hz , 3-H), 5.40 (1H, d, J = 1.7Hz, 7-H), 4.49 (1H, dd, J = 1.8Hz, J = 8.7Hz, 6-H), 4.35 (1H, dd, J = 9.4Hz, J = 9.8Hz, 5-H), 4.26 (1H, dd, J = 2.4Hz, J = 6.7Hz, 4-H), 3.77 (3H, s, CH ₃ ), 2.87 (1H, d , NHCH ₃ ), 2.22 (3H, s, OAc), 1.97 (3H, s, NAc); ¹³ C NMR (400MHz, CDCl ₃ 20.82 (OCOCH): ₃ ), 23.00 (NHCOCH ₃ ), 26.26 (NHCH ₃ ) , 48.45(C-5), 52.53(OCH ₃ ), 58.80(C-4), 70.59(C-7), 77.32(C-6), 108.34(C-3), 144.70(C-2), 161.47 (COO), 168.90 (C=O), 169.84 (C=O), 170.61 (C=O).

Example 4 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-ethylamino-2'-oxyethyl]-4-azide Methyl-3,4-dihydropyran-6-carboxylate

The title compound was prepared in the same manner as in Example 3, using ethylamine instead of methylamine; yield: 67%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.53 (1H, d, J = 9.4Hz, NH), 6.32 (1H, m, NH), 5.95 (1H, d, J = 2.4Hz, 3-H) , 5.42 (1H, d, J = 1.9Hz, 7-H), 4.53 (1H, dd, J = 2.1Hz, J = 10.4Hz, 6-H), 4.33 (1H, dd, J = 9.4Hz, J = 19.1Hz, 5-H), 4.25 (1H, dd, J = 2.5Hz, J = 8.9Hz, 4-H), 3.78 (3H, s, CH ₃ ), 3.49 (1H, m, CH), 3.22 (1H, m, CH), 2.24 (3H, s, OAc), 1.98 (3H, s, NAc), 1.20 (3H, t, J = 7.1 Hz, CH ₃ ); HRMS (ESI): m/z calculation Value _{: C15H22N5O7} [M+H] ⁺ _384.1519 , Found _: 384.1535.

Example 5 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-amino-2'-oxyethyl]-4-azido- 3,4-Dihydropyran-6-carboxylic acid methyl ester

The compound of Example 2 (369mg, 0.73mmol) was dissolved in THF (15mL), ammonia methanol (0.2mL, 0.87mmol, 1.2eq.) was added slowly, and the reaction was stopped after stirring at room temperature for 30min. After concentration under reduced pressure, column chromatography (EtOAc: petroleum ether = 1:1 (v/v)) gave the title compound 206 mg, yield: 80%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.59 (1H, s, NH), 6.49 (1H, s, NH), 6.06 (1H, d, J=6.6Hz, NH), 5.96 (1H, s, 3-H), 5.44 (1H, s, 7-H), 4.56 (1H, d, J=5.1Hz, 6-H), 4.28 (1H, s, 4-H and 5-H), 3.79 (3H , s, _CH3 ), 2.23 (3H, s, OAc), 1.98 (3H, s, NAc); LRMS (ESI): m/z [M+Na] ⁺ = 378.0.

Example 6 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-dimethylamino-2'-oxyethyl]-4- alkene Nitro-3,4-dihydropyran-6-carboxylic acid methyl ester

The title compound was prepared in the same manner as in Example 5, using dimethylamine instead of ammonia methanol; yield: 86%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.24 (1H, d, J = 6.8Hz, NH), 6.05 (1H, d, J = 3.6Hz, 7-H), 5.87 (1H, d, J = 2.1Hz, 3-H), 4.74(1H, t, J=6.5Hz, 4-H), 4.58(1H, dd, J=3.7Hz, J=6.3Hz, 6-H), 4.12(1H, dd , J=7.1Hz, J=14.4Hz, 5-H), 3.81(3H, s, CH ₃ ), 3.13(3H, s, CH ₃ ), 2.99(3H, s, CH ₃ ), 2.15(3H, s, OAc), 1.99 (3H, s, NAc); HRMS _{( EI )} : m/z calcd: _C15H22N5O7 [M+H] ⁺ 384.1519; found: 384.1527.

Example 7 (2R, 3R, 4S)-3-Acetamido-2-[(S)-1'-Acetoxy-2'-Diethylamino-2'-Oxyethyl]-4-Alkyl Nitro-3,4-dihydropyran-6-carboxylic acid methyl ester

The title compound was prepared in the same manner as in Example 5, using diethylamine instead of ammonia methanol; yield: 90%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.29 (1H, d, J = 7.5Hz, NH), 6.05 (1H, d, J = 3.6Hz, 3-H), 5.87 (1H, d, J = 6.3Hz, 7-H), 4.75(1H, t, J=6.3Hz, 6-H), 4.56(1H, dd, J=3.6Hz, J=6.3Hz, 4-H), 4.03(1H, dt , J=6.9Hz, J=13.8Hz, 5-H), 3.80(3H, s, CH ₃ ), 3.37(4H, m, 2CH ₂ ), 2.15(3H, s, OAc), 1.99(3H, s , NAc), 1.15 (6H, m, _2CH3 ); LRMS (EI): m/z [M+H] ⁺ = 412.0.

Example 8 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-hydroxylamino-2'-oxyethyl]-4-azido -3,4-Dihydropyran-6-carboxylic acid methyl ester

Example 2 compound (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-pentafluorophenoxy-2'-oxyethyl]- 4-Azido-3,4-dihydropyran-6-carboxylic acid methyl ester (200mg, 0.04mmol) was dissolved in THF (5mL), and hydroxylamine hydrochloride (30mg, 0.043mmol, 1.1eq.) and diiso Propylethylamine (DIPEA) (7.5 μL, 0.043 mmol, 1.1 eq.), was stirred at room temperature for 30 min, and then the reaction was stopped. After concentration under reduced pressure, separation by column chromatography (EtOAc) gave 131 mg of the title compound, yield: 92%.

¹ H NMR (300MHz, D ₂ O): δ6.20 (1H, d, J = 2.8Hz, 3-H), 5.57 (1H, d, J = 2.2Hz, 7-H), 4.66 (1H, t , J=2.1Hz, J=10.5Hz, 6-H), 4.51(1H, dd, J=2.9Hz, J=9.6Hz, 4-H), 4.29(1H, t, J=9.9Hz, 5- H), 3.89 (3H, s, _CH3 ), 2.28 (3H, s, OAc), 2.09 (3H, s, NAc); LRMS (ESI): m/z [M+Na] ⁺ = 478.1.

Example 9 (2R, 3R, 4S)-3-Acetamido-2-[(S)-1'-Acetoxy-2'-Cyclopentylamino-2'-Oxyethyl]-4-Alkene Nitro-3,4-dihydropyran-6-carboxylic acid methyl ester

The title compound was prepared by the same method as in Example 5, using cyclopentylamine instead of ammonia methanol; yield: 98%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.78 (1H, d, J = 8.3Hz, NH), 5.99 (1H, d, J = 3.0Hz, 3-H), 5.56 (1H, d, J = 4.4Hz, 7-H), 4.66(1H, dd, J=4.8Hz, J=9.1Hz, 6-H), 4.56(1H, dd, J=2.8Hz, J=7.8Hz, 4-H), 4.11 (1H, dt, J=8.5Hz, J=16.5Hz, 5-H), 3.69 (4H, m, 2CH ₂ ), 3.79 (3H, s, CH ₃ ), 2.16 (3H, s, OAc), 1.99 (3H, s, NAc), 1.92 (4H, m, _2CH2 ); LRMS (ESI): m/z [M+H] ⁺ = 410.0.

Example 10 (2R, 3R, 4S)-3-Acetamido-2-[(S)-1'-Acetoxy-2'-Dimethylamino-2'-Oxyethyl]-4-Alkyl Nitro-N-hydroxy-3,4-dihydropyran-6-carboxamide

Dissolve the compound of Example 6 (100 mg, 0.26 mmol) in CH ₃ OH (5 mL), add NH ₂ OH/KOH/CH ₃ OH solution (1.0 mL, 0.72 mmol), and stir at room temperature for 10 min, TLC shows that the reaction is complete, Add glacial acetic acid to adjust the pH of the system to 6.5. The reaction solution of the title compound obtained can be directly used in the next step without treatment.

HRMS ( _{ESI )} : m/z calcd: _C12H18N6O6Na [M+Na] ⁺ _365.1186 , found: 365.1181.

Example 11 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-dimethylamino-2'-oxyethyl]-4-amino-N -Hydroxy-3,4-dihydropyran-6-carboxamide

Lindlar (10 mg) catalyst was added to the reaction solution of Example 10, and after 48 hours of hydrogenation reaction at room temperature and normal pressure, TLC showed that the reaction was complete, so the reaction was stopped, and glacial acetic acid was added to the reaction system to adjust the pH of the system to 6.5. After filtering with celite, the title compound was separated by reverse-phase silica gel column chromatography to obtain 16 mg, yield: 20%.

¹ H NMR (300MHz, D ₂ O): δ5.76 (1H, d, J=2.3Hz, 3-H), 4.56 (1H, dd, J=2.0Hz, J=9.8Hz, 6-H), 4.37(1H, t, J=9.5Hz, 5-H), 4.31(1H, dd, J=2.2Hz, J=9.6Hz, 4-H), 3.14(3H, s, CH ₃ ), 3.05(3H , s, _CH3 ) _, 2.15 ( _3H , s, _NAc ); HRMS (ESI): m/z calcd: _C12H20N4O6Na [M+Na] ⁺ 339.1281, found: 339.1266.

Example 12 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-methylamino-2'-oxyethyl]-4-[4 '-Hydroxymethyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid methyl ester

Dissolve the compound of Example 3 (60mg, 0.16mmol) in ethanol aqueous solution (0.5mL), add propynyl alcohol (11μL, 0.16mmol), and then add freshly prepared sodium ascorbate (0.38mL, 30%mmol, 25mg/mL ), aqueous solution of copper sulfate pentahydrate (0.21 mL, 5% mmol, 0.4 mg/mL), under dark conditions, stirred at room temperature for 18 h, and evaporated the solvent under reduced pressure. The title compound (48mg, 70%) was obtained by column chromatography using ethyl acetate:methanol=25:1 (v/v) as eluent.

¹ H NMR (400MHz, CDCl ₃ ): δ7.72 (1H, s, CH), 7.44 (1H, d, J=9.2Hz, NH), 6.42 (1H, d, J=4.1Hz, NH), 6.03 (1H, d, J = 2.1Hz, 3-H), 5.71 (1H, dd, J = 2.5Hz, J = 10.6Hz, 4-H), 5.61 (1H, s, 7-H), 4.85 (1H , d, J=1.3Hz, J=10.7Hz, 6-H), 4.77 (2H, s, CH ₂ ), 4.56 (1H, dt, J=10.5Hz, J=20.1Hz, 5-H), 3.79 (3H, s, CH ₃ ), 2.91 (3H, d, J=4.8Hz, CH ₃ ), 2.18 (3H, s, OAc), 1.80 (3H, s, NHAc); HRMS (EI) m/z calculation Value: C ₁₇ H ₂₃ N ₅ O ₈ [M] ⁺ 425.1547, Found: 425.1512.

Example 13 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-methylamino-2'-oxyethyl]-4-[4'- Hydroxymethyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid

Example 12 (20 mg, 0.04 mmol) was dissolved in methanol (0.4 mL), and NaOH in methanol (0.17 mL, 0.16 mmol, 24 mg/mL) was added. After stirring at room temperature for 2 h, TLC showed that the reaction was complete, and then Dowex 50W×8 (H ⁺ ) was added to adjust the pH of the system to 7. After filtration, it was concentrated under reduced pressure to obtain the title compound (16 mg, 92%).

¹ H NMR (400MHz, DMSO): δ8.27 (1H, d, J = 8.8Hz, NH), 7.90 (1H, s, CH), 7.79 (1H, d, J = 4.8Hz, NH), 5.81 ( 1H, d, J = 2.3Hz, 3-H), 5.57 (1H, dd, J = 1.9Hz, J = 9.7Hz, 4-H), 4.51 (2H, m, 6-H and 7-H), 4.47 (2H, s, CH ₂ ), 4.29 (1H, dt, J=10.2Hz, J=18.1Hz, 5-H), 2.62 (2H, d, J=3.7Hz, CH ₃ ), 1.75 (3H, s, NHAc); HRMS (ESI): [M+H] ⁺ = 369.9; HRMS (EI) m/z calcd: C ₁₄ H ₂₁ N ₅ O ₇ Na [M+Na] ⁺ 392.1182, found: 392.1170 .

Example 14 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-methylamino-2'-oxyethyl]-4-[4 '-Methoxycarbonyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid methyl ester

The title compound was prepared in the same manner as in Example 12, using methyl propiolate instead of propynyl alcohol; yield: 72%.

¹ H NMR (400MHz, CDCl ₃ ): δ8.26 (1H, s, CH), 7.30 (1H, t, J=9.6Hz, NH), 6.43 (1H, d, J=4.9Hz, NH), 6.04 (1H, d, J = 2.2Hz, 3-H), 5.80 (1H, dd, J = 2.3Hz, J = 10.0Hz, 4-H), 5.57 (1H, d, J = 1.6Hz, 7-H ), 4.90(1H, dd, J=1.7Hz, J=10.8Hz, 6-H), 4.57(1H, dt, J=9.7Hz, J=19.8Hz, 5-H), 3.93(3H, s, CH ₃ ), 3.80 (3H, s, CH ₃ ), 2.92 (3H, d, J=4.8Hz, CH ₃ ), 2.19 (3H, s, OAc), 1.83 (3H, s, NHAc); HRMS (EI ) m _/ z calcd: _C18H24N5O9 [M+H] ⁺ _454.0574 , _found : 454.1603.

Example 15 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-methylamino-2'-oxyethyl]-4-[4'- Carboxy-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid

According to the same method as in Example 13, the title compound was prepared from the compound of Example 14; yield: 92%.

¹ H NMR (400MHz, DMSO): δ8.63 (1H, s, CH), 7.82 (1H, m, NH), 5.91 (1H, d, J=2.3Hz, 3-H), 5.60 (1H, dd , J=1.9Hz, J=9.8Hz, 4-H), 4.58(1H, d, J=11.3Hz, 6-H), 4.33(1H, m, 5-H), 4.09(1H, s, 7 -H), 2.64 (5H, d, J = 3.6 Hz, CH ₃ ), 1.74 (3H, s, NHAc); HRMS (ESI) m/z calcd: C ₁₄ H ₁₇ N ₅ O ₈ Na[M+ Na] ⁺ 406.0975, found: 406.0991.

Example 16 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-methylamino-2'-oxyethyl]-4-[4 '-(3"-Aminophenyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid methyl ester

The title compound was prepared in the same manner as in Example 12, using phenylacetylene instead of propynyl alcohol; yield: 61%.

¹ H NMR (400MHz, CDCl ₃ ): δ7.92 (1H, s, CH), 7.82 (2H, d, J=7.3Hz, PhH), 7.43 (2H, t, J=7.3Hz, PhH), 7.34 (1H, t, J = 7.3Hz, PhH), 6.98 (1H, d, J = 9.7Hz, NH), 6.37 (1H, d, J = 5.5Hz, NH), 6.09 (1H, d, J = 2.4 Hz, 3-H), 5.79 (1H, dd, J=2.6Hz, J=10.1Hz, 4-H), 5.61 (1H, d, J=1.5Hz, 7-H), 4.88 (1H, dd, J=1.9Hz, J=10.6Hz, 6-H), 4.66(1H, dt, J=9.9Hz, J=20.0Hz, 5-H), 3.81(3H, s, CH ₃ ), 2.93(3H, d, J = 5.1 Hz, CH ₃ ), 2.22 (3H, s, OAc), 1.82 (3H, s, NHAc); HRMS (EI) m/z calcd: C ₂₂ H ₂₆ N ₅ O ₇ [M+ H] ⁺ 472.1832, Found: 472.1809.

Example 17 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-methylamino-2'-oxyethyl]-4-[4'- (3”-Aminophenyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid

According to the same method as in Example 13, the title compound was prepared from the compound of Example 16; yield: 90%.

¹ H NMR (400MHz, DMSO): δ8.59 (1H, s, CH), 8.25 (1H, d, J = 8.7Hz, NH), 7.85 (2H, d, J = 7.8Hz, PhH), 7.80 ( 1H, d, J = 4.8Hz, NH), 7.42 (2H, t, J = 7.5Hz, PhH), 7.31 (1H, t, J = 7.5Hz, PhH), 5.90 (1H, d, J = 2.0Hz , 3-H), 5.61 (1H, d, J = 10.0Hz, 4-H), 4.59 (1H, d, J = 11.1Hz, 6-H), 4.31 (1H, dt, J = 10.0Hz, J =20.5Hz, 5-H), 4.08(1H, s, 7-H), 2.64(3H, d, J=3.7Hz, _CH3 ), 1.74(3H, s, NHAc); _M +H] ⁺ = 415.9; _HRMS (EI) m/z calcd: _C19H21N5O6Na [M+Na] ⁺ _438.1390 , found: 438.1367.

Example 18 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-cyclopentylamino-2'-oxyethyl]-4-[ 4'-Methoxycarbonyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid methyl ester

According to the same method as in Example 12, the title compound was prepared by using the compound in Example 9 as a raw material and using methyl propiolate instead of propynyl alcohol; yield: 55%.

¹ H NMR (400MHz, DMSO): δ8.86 (1H, s, CH), 6.08 (1H, d, J=2.7Hz, 3-H), 5.61 (1H, dd, J=2.3Hz, J=9.6 Hz, 6-H), 5.31 (1H, d, J = 2.4Hz, 7-H), 4.74 (1H, dd, J = 2.7Hz, J = 10.3Hz, 4-H), 4.39 (1H, t, J=10.0Hz, 5-H), 3.87 (1H, m, CH), 3.83 (3H, m, CH ₃ ), 3.74 (3H, m, CH ₃ ), 3.31 (3H, m, CH ₂ +CH) , 2.04 (3H, s, OAc), 1.87 (4H, m, 2CH ₂ ), 1.66 (3H, s, NHAc); HRMS (ESI): [M] ⁺ = 494.0, 516.1; HRMS (ESI) m/z Calcd: _C21H27N5O9Na [MH] _{+ 516.1706} , Found: ^516.1714 _.

Example 19 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-cyclopentylamino-2'-oxyethyl]-4-[4' -Carboxy-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid

According to the same method as in Example 13, the title compound was prepared from the compound of Example 18; yield: 76%.

¹ H NMR (400MHz, DMSO): δ8.62 (1H, s, CH), 5.87 (1H, d, J=2.1Hz, 3-H), 5.60 (1H, d, J=2.2Hz, J=9.5 Hz, 6-H), 4.56 (1H, dd, J = 2.4Hz, J = 10.3Hz, 4-H), 4.33 (1H, d, J = 2.1Hz, 7-H), 4.24 (1H, t, J=9.8Hz, 5-H), 3.74 (1H, m, CH), 3.30 (3H, m, CH ₂ +CH), 1.80 (4H, m, 2CH ₂ ), 1.71 (3H, s, NHAc); HRMS (ESI): [M+H] ⁺ = _424.0 , 445.9; HRMS ( _ESI ) m/z calcd: _C17H21N5O8Na [M+Na] ⁺ _446.1288 , found: 446.1266.

Example 20 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-cyclopentylamino-2'-oxyethyl]-4-[ 4'-(3"-Aminophenyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid methyl ester

According to the same method as in Example 12, the title compound was prepared by using the compound in Example 9 as a raw material and using cyclopropylacetylene instead of propynyl alcohol; yield: 38%.

¹ H NMR (400MHz, DMSO): δ7.83 (1H, s, CH), 5.97 (1H, d, J = 2.4Hz, 3-H), 5.47 (1H, dd, J = 2.6Hz, J = 9.5 Hz, 6-H), 5.25 (1H, d, J = 2.8Hz, 7-H), 4.68 (1H, dd, J = 2.5Hz, J = 9.9Hz, 4-H), 4.27 (1H, t, J=10.0Hz, 5-H), 3.82 (1H, m, CH), 3.71 (3H, m, CH ₃ ), 3.27 (3H, m, CH ₂ +CH), 2.03 (3H, s, OAc), 1.85 (4H, m, 2CH ₂ ), 1.68 (3H, s, NHAc), 0.86 (2H, m, CH ₂ ), 0.67 (2H, m, CH ₂ ); HRMS (ESI): [M] ⁺ = 498.2 , 510.1.

Example 21 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-cyclopentylamino-2'-oxyethyl]-4-[4' -(3”-aminophenyl-1,2,3-triazole-1]-3,4-dihydropyran-6-carboxylic acid

According to the same method as in Example 13, the title compound was prepared from the compound of Example 20; yield: 90%.

¹ H NMR (400MHz, CDCl ₃ ): δ7.79(1H, s, CH), 5.83(1H, d, J=2.5Hz, 3-H), 5.51(1H, d, J=2.3Hz, J= 9.3Hz, 6-H), 4.55(1H, dd, J=2.5Hz, J=10.2Hz, 4-H), 4.29(1H, d, J=2.5Hz, 7-H), 4.13(1H, t , J=9.9Hz, 5-H), 3.75 (1H, m, CH), 3.25 (3H, m, CH ₂ +CH), 1.83 (4H, m, 2CH ₂ ), 1.73 (3H, s, NHAc) , 0.86 (2H, m, CH ₂ ), 0.67 (2H, m, CH ₂ ); HRMS (ESI): [M+H] ⁺ = 420.0, 442.1; HRMS (ESI) m/z calcd: C ₁₉ H _25N5O6Na [M] ⁺ _442.1703 , Found _: 442.1705.

Example 22 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-methylamino-2'-oxyethyl]-4-amino-3, 4-Dihydropyran-6-carboxylic acid

The compound of Example 3 (78 mg, 0.21 mmol) was dissolved in 0.3 mL of H ₂ O, and 1,8-diazacyclo[5,4,0]undecene-7 (DBU) (0.22 mL, 1.47 mmol , 7.0eq.), after stirring at room temperature for 2h, TLC showed that the reaction was complete. After adding Lindlar catalyst (8 mg) to the reaction system, H ₂ was introduced into the reaction system for 24 hours, TLC showed that the reaction was complete, and the reaction was stopped. The insoluble matter was removed by filtration, and 42 mg of the title compound was obtained by separation with ion exchange resin, yield: 70%.

¹ H NMR (300MHz, D ₂ O): δ5.71 (1H, d, J = 2.6Hz, 3-H), 4.53 (1H, d, J = 10.9Hz, 6-H), 4.42 (1H, s , 7-H), 4.34 (1H, t, J=9.9Hz, 5-H), 4.15 (1H, dd, J=1.4Hz, J=9.2Hz, 4-H), 2.87 (3H, s, CH ₃ ), 2.12 (3H, s, NAc); MS (ESI): m/z (%) = 287.1 (100) [M+H ⁺ ]. LRMS (ESI): m/z [M + Na] ⁺ = 288.0.

Example 23 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-methylamino-2'-oxyethyl]-4-guanidino-3 , 4-Dihydropyran-6-carboxylic acid

Dissolve the compound of Example 22 (10 mg, 0.035 mmol) in 0.3 mL of H ₂ O, add amidinopyrazole monohydrochloride (7.6 mg, 0.042 mmol, 1.5 eq) and imidazole (11.8 mg, 0.17 mmol, 5.0 eq .), after stirring for 24h, 4 drops of Et ₃ N were added, and after stirring for 12h, TLC showed that the reaction was complete. The reaction solution was separated by ion exchange resin to remove part of the raw materials, and then separated by reverse phase silica gel column chromatography (eluent: water) to obtain 8.4 mg of the title compound with a yield of 74%.

¹ H NMR (400MHz, D ₂ O): δ5.64 (1H, d, J = 2.5Hz, 3-H), 4.54 (1H, dd, J = 1.9Hz, J = 10.4Hz, 6-H), 4.46(1H, dd, J=2.4Hz, J=6.8Hz, 4-H), 4.39(1H,dd, J=2.0Hz, J=4.5Hz, 7-H), 4.26(1H, t, J= 10.1 Hz, 5-H), 2.84 (3H, s, _CH3 ), 2.04 (3H, s, NAc); LRMS (ESI): m/z [M+H] ⁺ = 330.1.

Example 24 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-methylamino-2'-oxyethyl]-4-amino-3, 4-Dihydropyran-6-carboxylic acid

According to the same method as in Example 22, the title compound was prepared from the compound of Example 6; yield: 70%.

¹ H NMR (300MHz, D ₂ O): δ5.74 (1H, d, J = 2.1Hz, 3-H), 4.90 (1H, d, J = 2.1Hz, 7-H), 4.54 (1H, dd , J=2.1Hz, J=9.6Hz, 6-H), 4.35(1H, t, J=9.6Hz, 5-H), 4.28(1H, dd, J=2.4Hz, J=9.3Hz, 4- H), 3.12 (3H, s, CH ₃ ), 3.03 (3H, s, CH ₃ ), 2.13 (3H, s, NAc); HRMS (EI): m/z calcd: C ₁₂ H ₁₉ N ₃ O ₆ Na[M+Na] ⁺ 324.1172, Found: 324.1163.

Example 25 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-dimethylamino-2'-oxyethyl]-4-guanidino- 3,4-Dihydropyran-6-carboxylic acid

According to the same method as in Example 23, the title compound was prepared from the compound of Example 24; yield: 74%.

¹ H NMR (300MHz, D ₂ O): δ5.72 (1H, d, J = 3.2Hz, 3-H), 4.55 (1H, dd, J = 4.2Hz, J = 8.2Hz, 6-H), 4.42 (1H, dd, J = 3.0Hz, J = 7.8Hz, 4-H), 4.21 (1H, t, J = 7.9Hz, 5-H), 3.13 (3H, s, CH ₃ ), 3.00 (3H , s, CH ₃ ), 2.06 (3H, s, NAc); ¹³ C NMR (400MHz, D ₂ O): δ19.03, 33.14, 45.23, 46.40, 63.49, 73.83, 100.57, 146.05, 154.19, 165.96, 168.50 , 171.87; HRMS (ESI) _: m/z calcd: _C13H21N5O6 [M+H] ⁺ _344.1570 , found _: 344.1577.

Example 26 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-ethylamino-2'-oxyethyl]-4-triphenyl Phosphinimido-3,4-dihydropyran-6-carboxylic acid methyl ester

Dissolve the compound of Example 4 (30 mg, 0.07 mmol) in THF (2.0 mL), add PPh ₃ (20 mg, 0.07 mmol, 1.05 eq.), stir at room temperature for 18 h, and concentrate under reduced pressure to obtain an oil. Preparative plate (CH ₂ Cl ₂ :CH ₃ OH=30:1 (v/v)) isolated the title compound 15 mg, yield: 30%.

¹ H NMR (300MHz, CDCl ₃ ): δ8.20 (1H, d, J=7.8Hz, NH), 7.73 (18H, m, 18PhH), 6.56 (1H, m, NH), 5.45 (1H, d, J=1.5Hz, 7-H), 5.40(1H, d, J=2.1Hz, 3-H), 4.98(1H, dd, J=1.5Hz, J=10.2Hz, 6-H), 4.82(1H , m, 4-H), 4.14 (1H, dt, J=10.5Hz, J=17.7Hz, 5-H), 3.67 (3H, s, CH ₃ ), 3.39 (1H, m, CH), 3.18 ( 1H, m, CH), 2.23 (3H, s, OAc), 1.76 (3H, s, NAc), 1.12 (3H, t, J=7.2Hz, CH ₃ ); LRMS (ESI): m/z [M +H] ⁺ = 618.3.

Example 27 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-ethylamino-2'-oxyethyl]-4-amino- 3,4-Dihydropyran-6-carboxylic acid methyl ester

Dissolve the compound of Example 4 (30 mg, 0.07 mmol) in THF (2.0 mL), add PPh ₃ (20 mg, 0.07 mmol, 1.05 eq.), stir at room temperature for 18 h, and concentrate under reduced pressure to obtain an oil. Preparative plate (CH ₂ Cl ₂ :CH ₃ OH=10:1 (v/v)) isolated the title compound 24 mg, yield: 50%.

¹ H NMR (300MHz, CDCl ₃ ): δ5.87 (1H, d, J = 2.5Hz, 3-H), 5.08 (1H, d, J = 1.8Hz, 7-H), 4.30 (1H, dd, J=1.6Hz, J=10.4Hz, 6-H), 3.76(1H, t, J=9.9Hz, 5-H), 3.68(3H, s, CH ₃ ), 3.40(1H, m, 4-H ), 3.24 (1H, m, CH), 2.99 (1H, m, CH), 2.11 (3H, s, OAc), 1.79 (3H, s, NAc), 1.03 (3H, t, J=7.1Hz, CH ₃ ); LRMS (ESI): m/z [M+Na] ⁺ = 380.1.

Example 28 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-ethylamino-2'-oxyethyl]-4-amino-3, 4-Dihydropyran-6-carboxylic acid

Dissolve the compound of Example 26 (15mg, 0.024mmol) in a mixed solution of methanol (0.75mL) and water (0.75mL), add KOH (0.3mL), stir at room temperature for 16h, and adjust the pH of the solution with 2mol/L hydrochloric acid =6-7, the title compound was obtained as a pale yellow solid after concentration under reduced pressure. It can be directly used in the next step without purification.

LRMS (ESI): m/z [MH] ⁺ = 300.1.

Example 29 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-ethylamino-2'-oxyethyl]-4-[2', 3'-di-tert-butoxycarbonylguanidino]-3,4-dihydropyran-6-carboxylic acid

Dissolve the compound of Example 28 in a mixed solution of methanol (0.2mL) and THF (0.2mL), then add N,N'-di-tert-butoxycarbonylamidinopyrazole (10.4mg, 0.04mmol), and stir at room temperature for 24h Afterwards, it was concentrated under reduced pressure and isolated on a preparative plate (CH ₂ Cl ₂ :CH ₃ OH=6:1 (v/v)) to obtain 10 mg of the title compound with a yield of 76%.

LRMS (ESI): m/z [M+Na] ⁺ = 566.1.

Example 30 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-ethylamino-2'-oxyethyl]-4-guanidino-3 , 4-Dihydropyran-6-carboxylic acid

Dissolve the compound of Example 29 (10mg, 0.02mmol) in CH ₂ Cl ₂ (0.2mL), then add CF ₃ COOH (0.1mL), stir at room temperature for 2h, then concentrate to dryness under reduced pressure, the ion exchange resin is separated to give white 6 mg of the title compound as a solid, yield: 96%.

¹ H NMR (300MHz, D ₂ O): δ5.65 (1H, d, J=2.4Hz, 3-H), 4.55 (1H, dd, J=2.1Hz, J=10.5Hz, 6-H), 4.48(1H, dd, J=2.4Hz, J=12.0Hz, 4-H), 4.39(1H,d, J=2.1Hz, 7-H), 4.28(1H, dt, J=7.8Hz, J= 17.7Hz, 5-H), 3.33(4H, dt, J=7.2Hz, J=14.4Hz, CH ₂ ), 2.07(3H, s, NAc), 1.17(6H, t, J=7.2Hz, CH ₃ ).

Example 31 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-diethylamino-2'-oxyethyl]-4-amino-3 , 4-Dihydropyran-6-carboxylic acid

According to the same method as in Example 22, the target compound was prepared from the compound in Example 7; yield: 93%.

¹ H NMR (300MHz, D ₂ O): δ5.73 (1H, d, J = 1.8Hz, 3-H), 4.74 (1H, d, J = 3.0Hz, 7-H), 4.47 (1H, dd , J=2.7Hz, J=9.0Hz, 6-H), 4.23(1H, dt, J=9.6Hz, J=18.6Hz, 5-H), 4.20(1H,dd, J=2.1Hz, J= 10.5Hz, 4-H), 3.43(4H, m, 2CH ₂ ), 2.10(3H, s, NAc), 1.23(3H, t, J=7.2Hz, CH ₃ ), 1.15(3H, t, J= 7.2 Hz, CH ₃ ); LRMS (ESI): m/z [M+H] ⁺ = 330.0.

Example 32 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-diethylamino-2'-oxyethyl]-4-amino -3,4-Dihydropyran-6-carboxylic acid methyl ester

Dissolve the compound of Example 7 (10 mg, 0.02 mmol) in THF (0.5 mL) and H ₂ O (4.4 μL, 0.2 mmol, 10 eq.), add PPh ₃ (7 mg, 0.02 mmol), stir at room temperature for 48 h, stop reaction. After concentration under reduced pressure, 4 mg of the title compound was isolated in a preparative plate (CH ₂ Cl ₂ :CH ₃ OH=6/1 (v/v)), yield: 43%.

¹ H NMR (300MHz, CDCl ₃ ): δ6.94 (1H, d, J = 8.7Hz, NH), 6.05 (1H, d, J = 3.0Hz, 3-H), 5.80 (1H, d, J = 4.5Hz, 7-H), 4.57(1H, dd, J=4.8Hz, J=8.4Hz, 6-H), 3.97(1H, dt, J=8.4Hz, J=16.5Hz, 5-H), 3.78 (3H, s, CH ₃ ), 3.73 (2H, m, CH and 4-H), 3.35 (3H, m, CH and CH ₂ ), 2.19 (3H, s, OAc), 1.99 (3H, s, NAc), 1.13 (6H, t, J = 6.9 Hz, _2CH3 ); LRMS (ESI): m/z [M+Na] ⁺ = 408.3.

Example 33 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-diethylamino-2'-oxyethyl]-4-[ 2',3'-di-tert-butoxycarbonylguanidino]-3,4-dihydropyran-6-carboxylic acid

The compound of Example 32 (60mg, 0.16mmol) was dissolved in anhydrous methanol (2mL), under _N2 protection, N, N'-di-tert-butoxycarbonylamidinopyrazole (60mg, 0.19mmol) was added dropwise in THF (2 mL) solution. After stirring at room temperature for 48 h, the solvent was spun off and separated directly with a preparative plate (CH ₂ Cl ₂ : _{CH 3} OH=10:1 (v/v)) to obtain 78 mg of the title compound as a white solid, yield: 80%.

¹ H NMR (300MHz, CDCl ₃ ): δ11.40 (1H, s, NH), 8.52 (1H, d, J=8.3Hz, NH), 6.66 (1H, d, J=8.5Hz, NH), 5.92 (1H, d, J = 2.3Hz, 3-H), 5.65 (1H, d, J = 4.2Hz, 7-H), 5.21 (1H, dd, J = 2.2Hz, J = 10.3Hz, 4-H ), 4.55(1H, dd, J=4.3Hz, J=l0.7Hz, 6-H), 4.25(1H, dt, J=9.9Hz, J=18.8Hz, 5-H), 3.84(3H, s , CH ₃ ), 3.36 (4H, m, 2CH ₂ ), 2.23 (3H, s, OAc), 1.91 (3H, s, NAc), 1.52 (9H, s, 3CH ₃ ), 1.51 (9H, s, 3CH ₃ ), 1.16 (3H, t, J = 6.9 Hz, CH ₃ ); LRMS (ESI): m/z [M+H] ⁺ = 628.1.

Example 34 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-diethylamino-2'-oxyethyl]-4-guanidine Methyl-3,4-dihydropyran-6-carboxylate

The compound of Example 33 (4 mg, 0.03 mmol) was dissolved in anhydrous CH ₂ Cl ₂ (0.5 mL), under the protection of N ₂ , a solution of CF ₃ COOH (0.2 mL) was added. After stirring at room temperature for 5 h, the solvent was spun off to obtain 3 mg of the title compound, which could be directly used in the next reaction.

LRMS (ESI): m/z [M+H] ⁺ = 372.2.

Example 35 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-diethylamino-2'-oxyethyl]-4-guanidino- 3,4-Dihydropyran-6-carboxylic acid

Example 34 compound (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-acetoxy-2'-diethylamino-2'-oxyethyl]-4 -Guanidino-3,4-dihydropyran-6-carboxylic acid methyl ester (3mg, 0.01mmol) was dissolved in H ₂ O (0.2mL) and 1M NaOH aqueous solution (2μL), after stirring at room temperature for 15h, the reaction was stopped . The title compound was separated by cation exchange resin to obtain 2 mg, yield: 73%.

¹ H NMR (300MHz, D ₂ O): δ5.79 (1H, d, J = 3.3Hz, 3-H), 4.80 (1H, d, J = 5.7Hz, 7-H), 4.61 (1H, t , J=6.0Hz, 6-H), 4.43 (1H, dd, J=3.3Hz, J=6.6Hz, 4-H), 4.23 (1H, dt, J=9.0Hz, J=15.9Hz, 5- H), 3.49 (4H, m, CH ₂ ), 2.11 (3H, s, NAc), 1.29 (6H, t, J=7.2Hz, 2CH ₃ ); LRMS (ESI): m/z [M+H] ⁺ = 372.2.

Example 36 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-cyclopentylamino-2'-oxyethyl]-4-amino-3 , 4-Dihydropyran-6-carboxylic acid

According to the same method as in Example 22, the title compound was prepared from the compound of Example 9; yield: 90%.

¹ H NMR (400MHz, D ₂ O): δ5.74 (1H, d, J = 3.0Hz, 3-H), 4.70 (1H, d, J = 2.5Hz, 7-H), 4.52 (1H, t , J=2.7Hz, J=10.2Hz, 6-H), 4.34(1H, t, J=9.4Hz, 5-H), 4.27(1H, dd, J=2.2Hz, J=9.4Hz, 4- H), 3.58 (4H, m, 2CH ₂ ), 2.12 (3H, s, NAc), 1.97 (4H, m, 2CH ₂ ); LR-ESI-MS: [M+Na] ⁺ =350.1.

Example 37 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-cyclopentylamino-2'-oxyethyl]-4-guanidino- 3,4-Dihydropyran-6-carboxylic acid

The title compound was prepared in the same manner as in Example 23, using the compound of Example 36 as a starting material; yield: 80%.

¹ H NMR (300MHz, D ₂ O): δ5.73 (1H, d, J = 3.0Hz, 3-H), 4.67 (1H, d, J = 4.5Hz, 7-H), 4.55 (1H, dd , J=4.5Hz, J=8.4Hz, 6-H), 4.43(1H, dd, J=3.0Hz, J=7.5Hz, 5-H), 4.237(1H, t, J=8.1Hz, 5- H), 3.69 (1H, m, CH), 3.51 (3H, m, CH+CH ₂ ), 2.06 (3H, s, NAc), 1.95 (4H, m, 2CH ₂ ); HRMS (ESI): [M +H] ⁺ = 370.2.

Examples 38-41

According to the same method as in Example 5, the compound of Example 2 was reacted with different amines to prepare the compounds of Examples 38-41, respectively.

Examples 42-47

According to the same method as in Example 31, the compounds of Examples 42-47 were correspondingly prepared from Examples 5, 38, 8, 39-41, respectively.

Examples 48-52

According to the same method as in Example 23, the compounds of Examples 48-52 were correspondingly prepared from Examples 42-46, respectively.

Examples 53-87

According to the same preparation method as in Example 12, the compounds of Examples 53-87 were prepared accordingly.

Examples 88-111

Following the same method as in Example 13, the compounds of Examples 88-111 were prepared accordingly.

Examples 112-115

Using the title compound of Example 2 as a raw material, the title compound was prepared by reacting with different amines or amino sugars in the same manner as in Example 5.

Examples 116-119

Using the title compounds of Examples 112-115 as raw materials, referring to the same method as in Example 22, the compounds of Examples 116-119 were prepared by first using DBU and then Lindlar catalyst.

Example 120 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-hydroxyethylamino-2'-oxyethyl]-4-guanidino -3,4-Dihydropyran-6-carboxylic acid

Dissolve 20 mg of the compound of Example 117 in H ₂ O (1.5 mL), add 46 mg of amidinopyrazole monohydrochloride and 116 μL of DIPEA, stir at room temperature overnight, and separate 15 mg of a light yellow solid with a cationic resin after the reaction is complete. title compound. ¹ H NMR (300MHz, D ₂ O): δ7.57 (1H, d, J = 1.5Hz, NH), 5.55 (1H, d, J = 2.1Hz, 3-H), 4.38 (1H, dd, J =1.2Hz, J=10.5Hz, 6-H), 4.27(1H, d, J=3.6Hz, 7-H), 4.21(1H, d, J=10.8Hz, 5-H), 4.08(1H, dd, J=2.4Hz, J=9.6Hz, 4-H), 3.54 (2H, t, J=5.4Hz, -CH2OH), 3.29 (2H, t, J=5.1Hz, -CH2NCO), 1.94 (3H , s, NAc); LRMS (ESI): m/z [M+Na] ⁺ = 360.3.

Example 121 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-morpholinyl-2'-oxyethyl]-4-amino-3, 4-Dihydropyran-6-carboxylic acid methyl ester

35 mg of the compound of Example 114 was dissolved in CH ₃ OH (1.0 mL), Lindlar catalyst (10 mg) was added, and H ₂ was introduced to react for 24 h. TLC showed that the reaction was complete, and the reaction was stopped. The cationic resin isolated 27 mg of product, the title compound.

Example 122 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-morpholinyl-2'-oxyethyl]-4-[2', 3'-di-tert-butoxycarbonylguanidino]-3,4-dihydropyran-6-carboxylic acid

Dissolve 27 mg of the compound of Example 121 in CH ₃ OH (1.0 mL), add 25 mg of N,N'-di-tert-butoxycarbonylamidinopyrazole, heat at 35°C for 24 h, TLC shows that the reaction is complete, and stop the reaction. The reaction solution was concentrated, separated and purified to obtain 30 mg of the title compound as a white solid.

Example 123 (2R, 3R, 4S)-3-acetamido-2-[(S)-1'-hydroxyl-2'-morpholinyl-2'-oxyethyl]-4-guanidino-3 , 4-Dihydropyran-6-carboxylic acid

Dissolve 30mg of the title compound of Example 122 in 0.5mL THF/0.5mL H ₂ O, add 2eq NaOH, stir at room temperature for 2h, adjust the pH to neutral with cationic resin, filter off the resin, and then add 0.5mL CF ₃ COOH , stirred at room temperature for 2 h, TLC showed that the reaction was complete, the reaction solution was concentrated, and cation resin was used to obtain 10 mg of the title compound as a light yellow solid. ¹ H NMR (300MHz, CD ₃ OD): δ5.70 (1H, d, J = 6.0Hz, 3-H), 4.82 (1H, d, J = 3.3Hz, 7-H), 4.54 (1H, dd , J=3.3Hz, J=8.4Hz, 6-H), 4.43(1H, dd, J=3.0Hz, J=7.8Hz, 4-H), 4.17(1H, t, J=8.4Hz, 5- H), 3.66 (8H, m, _-CH2 ), 2.04 (3H, s, NAc), ; LRMS (ESI): m/z [M+H] ⁺ = 386.3.

The neuraminidase inhibitory activity assay of compound of the present invention:

Referring to the literature (Bioorg. & Med. Chem. Lett. 2007, 17, 1655-1658), the inhibitory activity of the compound of general formula (I) of the present invention on influenza virus H3N2 was determined. The measurement results are as follows:

As can be seen from the above table, the compounds described in the present invention have obvious inhibitory activity against influenza virus, and the structure of this type of compound is different from that of zanamivir, and can be used for the treatment of influenza virus resistant to zanamivir, and The polarity of the compound is reduced, which facilitates oral administration.

Moreover, in the overall anti-influenza virus mouse model, compound 25 was administered orally, and the doses of 50 mg/kg and 100 mg/kg all showed obvious antiviral efficacy, and it was dose-dependent, indicating that the compound is not only effective in vitro , also effective in animals.

Thus, the present invention provides a class of N-acetylneuraminic acid compounds with novel structure and high activity, which can be used for anti-influenza virus, especially for zanamivir, Treatment of influenza virus infection resistant to other anti-influenza drugs such as seltavir. Moreover, the typical compounds of this type of compound have less polarity than zanamivir, can be administered orally, and have improved oral bioavailability.

Claims (13)

1. N-acetylneuraminic acid compounds or their pharmaceutically acceptable salts shown in the following general formula (I): in: R ¹ represents NR ⁵ R ⁶ or N(OR ⁵ )R ⁶ ; R ² represents H or COR ⁵ ; R ³ represents NR ⁷ R ⁸ or NHC (=NR ⁹ )NR ⁵ R ¹⁰ , which is in α configuration; R ⁴ represents COOR ⁵ ; R ⁵ and R ⁶ each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, aryl or optionally replaced by one or more A five-membered or six-membered monosaccharide group substituted by a substituent selected from hydroxyl protecting group, C ₁ -C ₆ alkyl, trimethylsilyl, benzyl and acetyl; or by OR ¹⁴ , C _3-8 C _1-10 alkyl, C _3-8 cycloalkyl, C _3-10 alkenyl or C _3-10 alkynyl substituted by cycloalkyl or aryl; Or R ⁵ and R ⁶ and their connected nitrogen atoms together form a ring structure, the ring structure is saturated or unsaturated, and contains one or more heteroatoms selected from N, O and S, the ring structure The structure is optionally substituted by halogen, C _1-10 alkyl, C ₁ - _{C 10} alkoxy, C _3-8 cycloalkyl, C _2-10 alkenyl or C _2-10 alkynyl; R ⁷ and R ⁸ each independently represent H, CN, C _1-6 alkyl, C _3-8 cycloalkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _2-6 hydrocarbon chain, The hydrocarbon chain optionally contains an NR ¹¹ group, and the hydrocarbon chain is optionally substituted by 1 to 4 groups selected from oxo and C _1-6 alkyl, and the C _1-6 alkane The group is optionally substituted with a hydroxyl or aryl group; R ⁹ and R ¹⁰ each independently represent H, C _1-6 alkyl, NR ¹⁴ R ¹⁵ , OR ¹⁴ , CN or NO ₂ ; R ¹¹ represents H, C _1-10 alkyl, C _3-8 cycloalkyl, COOR ⁵ or aryl; or optionally substituted by hydroxyl, amino, amino, COOR ⁵ or C _1-6 alkoxy C _1-10 alkyl; R ¹⁴ and R ¹⁵ each independently represent H, C _1-6 alkyl, C _3-8 cycloalkyl or aryl; Wherein, the aryl refers to an aromatic carbocyclic or heterocyclic group, and is optionally substituted; when the aryl is substituted, the substituent includes C _1-4 alkyl, C _1-4 alkane Oxygen, halogen, nitro, trifluoromethyl, amino, C _1-4 alkyl substituted amino, phenyl and benzyl; the aryl is substituted by 1 to 3 of the above substituents. 2. N-acetylneuraminic acid compounds represented by formula (I) according to claim 1 or their pharmaceutically acceptable salts, wherein, R ¹ represents NR ⁵ R ⁶ or N(OR ⁵ )R ⁶ ; R ² represents H or COR ⁵ ; R ³ is α configuration; R ³ represents NR ⁷ R ⁸ or NHC (=NR ⁹ ) NR ⁵ R ¹⁰ ; R ⁴ represents COOR ⁵ ; R ⁵ and R ⁶ independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, rhamnosyl, mannosyl, glucose group, C _1-10 alkyl substituted by hydroxy, C _3-8 cycloalkyl substituted by hydroxy, C _3-10 alkenyl substituted by hydroxy or C _3-10 alkynyl substituted by hydroxy; or R ⁵ and R ⁶ together with the nitrogen atoms connected to them form a ring structure, the ring structure is saturated or unsaturated, and contains one or more heteroatoms selected from N, O and S, the ring structure is not necessarily Substituted by C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl or C _2-10 alkynyl; R ⁷ and R ⁸ each independently represent H, CN, C _1-6 alkyl, C _3-8 cycloalkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _2-6 hydrocarbon chain, The hydrocarbon chain optionally contains a NR ¹¹ group, the hydrocarbon chain is optionally substituted by 1 or 2 groups selected from oxo and C _1-6 alkyl, and the C _1-6 alkane The base is optionally substituted by hydroxyl or aryl; the aryl includes phenyl, naphthyl, pyridyl, imidazolyl and thienyl, and is optionally substituted; when the aryl is substituted, the substituted The group includes C _1-4 alkyl, C _1-4 alkoxy, nitro, amino, phenyl and benzyl; and the substituted aryl has 1 to 3 of the above substituents; R ⁹ and R ¹⁰ each independently represent H, C _1-6 alkyl, NH ₂ , OH, CN or NO ₂ ; R ¹¹ represents H, C _1-10 alkyl, C _3-8 cycloalkyl or COOR ⁵ . 3. N-acetylneuraminic acid compounds represented by formula (I) according to claim 2 or their pharmaceutically acceptable salts, wherein, R ¹ represents NR ⁵ R ⁶ ; ^R2 represents H; R ³ represents NH ₂ or NHC(=NH)NH ₂ , which is in α configuration; R ⁴ represents COOR ⁵ ; R ⁵ and R ⁶ each independently represent H, C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl, C _2-10 alkynyl, mannosyl, glucosyl or substituted by hydroxyl C _1-10 alkyl; or R ⁵ and R ⁶ and their connected nitrogen atoms together form a ring structure, the ring structure is saturated or unsaturated, and contains one or more selected from N, O and S The heteroatom in the ring structure is optionally substituted by C _1-10 alkyl, C _3-8 cycloalkyl, C _2-10 alkenyl or C _2-10 alkynyl. 4. N-acetylneuraminic acid compounds shown in formula (I) according to claim 1 or their pharmaceutically acceptable salts, is characterized in that, it is selected from: 5. N-acetylneuraminic acid compounds or their pharmaceutically acceptable salts shown in formula (I) according to claim 4, is characterized in that, it is selected from: 6. the preparation method of the N-acetylneuraminic acid compound shown in the formula (I) described in claim 1 or their pharmaceutically acceptable salt, it is characterized in that, adopt any one in following method: (1) When R ¹ in the compound of general formula (I) is NR ⁵ R ⁶ or N(OR ⁵ ) R ⁶ , that is, the compound of general formula (Id), represented by R ¹ in the corresponding compound of general formula (I) The compound of the general formula (Ib) of OH is prepared by reacting a nitrogen-containing compound substituted by -R ⁵ R ⁶ or -(OR ⁵ ) R ⁶ ; the carboxyl group is activated before reacting with the amine; the amination reaction is completed in an organic solvent; (2) When R in the compound of general formula (I) ³ is NH ₂ When, that is, the compound of general formula (Ig), the compound of general formula (Ie) represented by R in the compound of corresponding general formula (I) represents _N ³ Azide reduction reaction to prepare; (3) When in the compound of general formula (I) R ³ is NR ⁷ R ⁸ , that is, the compound of general formula (Ih), from the compound of general formula (I) R ³ is NH ₂ The compound of general formula (Ig) passes Prepared by reacting with compounds substituted by R ^{and R} ; (4) When R ³ in the compound of general formula (I) is NHC (=NR ¹⁴ ) NR ¹⁵ R ¹⁶ , that is, the compound of general formula (Ii), R ³ in the compound of general formula (I) is NR ⁷ R ⁸ The compound of general formula (Ih) is prepared by guanidinylation; when R in the compound of general formula (I) ³ is NHC (=NH) NH ₂ When, that is, the compound of general formula (Ik), through the compound of general formula (I) In R ³ is NH ₂ The compound of general formula (Ig) reacts with amidinopyrazole or its salt or derivative or passes through the compound of general formula (I) In the compound R ³ It is prepared by the compound of intermediate formula (Ij) of NHCN; (5) In the compound of general formula (I), R ³ is NR ⁷ R ⁸ in the compound of general formula (Ih) or in the compound of general formula (I), R ³ is in the compound of general formula (Ii) NHC (=NR ¹⁴ ) NR ¹⁵ R ¹⁶ ) compound is prepared from the compound of general formula (I) in which R ³ represents N ₃ , and R ⁴ is CONR ⁵ R ⁶ by reducing the azido reduction method similar to the above method (2), and then further reacting; or (6) Other compounds of the general formula (I) can be prepared by the mutual conversion of functional groups between different compounds of the general formula (I); wherein R ² is H The compound is prepared by a compound other than H; R ⁷ and R ⁸ Compounds that are not H are prepared by corresponding compounds where R ⁷ and/or R ⁸ are H; R ⁴ is COOR ⁵ and R ⁴ is COOH compounds are interconverted. 7. the preparation method of the N-acetylneuraminic acid compound shown in formula (I) according to claim 6 or their pharmaceutically acceptable salt, it is characterized in that, when preparing general formula (Id) compound, carboxyl Methods for activation prior to reaction with amines include conversion to pentafluorophenoxy; amination is done in ether. 8. according to the preparation method of the N-acetylneuraminic acid compound shown in formula (I) according to claim 6 or their pharmaceutically acceptable salt, it is characterized in that, when preparing general formula (Ig) compound, the The above reduction conditions are catalyzed by Lindlar catalyst, hydrogen or formic acid provides active hydrogen. 9. Use of the N-acetylneuraminic acid compounds represented by formula (I) or their pharmaceutically acceptable salts in the preparation of neuraminidase inhibitors according to any one of claims 1 to 5. 10. Use of the N-acetylneuraminic acid compounds represented by formula (I) or their pharmaceutically acceptable salts according to any one of claims 1 to 5 in the preparation of medicaments for inhibiting viruses. 11. Use according to claim 10, characterized in that the virus is an influenza virus. 12. N-acetylneuraminic acid compounds represented by formula (I) according to any one of claims 1 to 5 or their pharmaceutically acceptable salts in the preparation of drugs for the prevention and treatment of viral diseases and infections thereof the use of. 13. A pharmaceutical composition for inhibiting neuraminidase, comprising a therapeutically effective amount of one or more N- Acetylneuraminic acid compounds or their pharmaceutically acceptable salts and one or more pharmaceutically acceptable carriers or diluents.