RU2237479C2 - Nucleosides with activity against hepatitis b virus - Google Patents

Abstract

FIELD: medicine, hepatology.

SUBSTANCE: the present innovation deals with treating infection induced by hepatitis B virus. For this purpose compounds and pharmaceutical compositions have been elaborated of specific antiviral activity, and, also, with the method to treat viral infection of hepatitis B. These elaborations deal with introduction of efficient quantity of

didoxy-5-fluocytosine derivatives. The present innovation provides pronounced antiviral effect at decreased toxic manifestations of therapy conducted.

EFFECT: higher efficiency of application.

100 cl, 4 dwg, 4 ex, 2 tbl

Description

This invention relates to the field of methods for controlling hepatitis B virus (also referred to as HBV), comprising administering an effective amount of one or more β- (L-2 'or 3'-azido) -2', 3'-dideoxy-5-fluorocytosines in need of this patient.

BACKGROUND OF THE INVENTION

HBV is the second cause of cancer in humans after tobacco. The mechanism for inducing HBV cancer is unknown, despite the suggestion that it can directly or indirectly cause tumor development as a result of chronic inflammation, cirrhosis and cell regeneration associated with the infection.

Hepatitis B virus has reached epidemic levels worldwide. After a two to six month incubation period during which the carrier is unaware of the infection, HBV infection can lead to acute hepatitis and liver damage, causing abdominal pain, jaundice, and elevated levels of certain enzymes in the blood. HBV can cause fulminant hepatitis, a rapidly progressive, often fatal form of the disease that affects large areas of the liver. Patients are usually cured of acute viral hepatitis. However, in some patients, a high level of viral antigen is retained in the blood for an extended or indefinite period of time, causing a chronic infection. Chronic infection can lead to persistent chronic hepatitis. Chronic persistent HBV infected patients are most common in developing countries. By mid-1991, there were approximately 225 million chronic HBV carriers in Asia alone, and nearly 300 million carriers worldwide. Chronic persistent hepatitis can cause fatigue, cirrhosis and hepatic cell carcinoma, primary liver cancer. In Western industrialized countries, high-risk groups for HBV include people who are in contact with HBV carriers or their blood samples. In fact, the epidemiology of HBV is very similar to the epidemiology of Acquired Immunodeficiency Syndrome, which explains why HBV infection is common among patients with AIDS or HIV-associated infections. However, HBV is more contagious than HIV.

Daily treatment with a-interferon, a genetically engineered protein, has been shown to be promising. A vaccine derived from human serum has also been developed to immunize patients against HBV. Vaccines were obtained as a result of genetic engineering. Despite its effectiveness, obtaining a vaccine is time-consuming, since obtaining human serum from chronic carriers is limited, and the cleaning procedure is lengthy and costly. In addition, each batch of vaccine obtained from different sera should be tested on chimpanzees for safety reasons. In addition, such a vaccine does not help patients already infected with the virus.

A number of synthetic nucleosides exhibiting anti-HBV activity have been developed. (-) - Enantiomer BCH-189 (2 ', 3'-dideoxy-3'-thiacytidine), known as ZTS, claimed in US patent No. 5 539 116 in the name of Liotta et al., Currently undergoing clinical trials for treatment hepatitis B. See also EPA 0 494 119 A1, filed by BioChem Pharma, Inc.

β-2-0-hydroxymethyl-5- (5-fluorocytosin-1-yl) -1,3-oxathiolane (“FTC”), as claimed in US Pat. Nos. 5,814,639 and 5,914,331 to Liotta et al. activity against HBV. See Furman et al., "The Anti-Hepatitis In Virus Activities, Cytotoxines, and Anabolic Profiles of the (-) and (+) Enantiomers of cis-5-Fluoro-1- [2- (Hydroxymethyl) -1.3 -oxathiolane-5-yl] -Cytosine "Antimicrobial Agents and Chemotherapy, December 1992, page 2686-2692; and Cheng et al., Journal of Biological Chemistry, Volume 267 (20), 13938-13942 (1992).

US Patent Nos. 5,565,438, 5,567,688 and 5,587,362 (Chu et al.) Describe the use of 2'-fluoro-5-methyl-β-b-arabinofuranolyluridine (L-FMAU) for the treatment of hepatitis B and Epstein-virus Barra

Penciclovir (2-amino-1,9-dihydro-9- [4-hydroxy-3-hydroxymethyl) butyl] 6H-purin-6-one; PCV) has established anti-hepatitis B activity. See U.S. Patents 5,075,445 and 5,684,153.

Adefovir (9- [2- (phosphonomethoxy) ethyl] adenine, also referred to as PMEA or [2- (6-amino-9H-purin-9-yl) ethoxy] methylphosphonic acid) also has established activity against hepatitis B. See ., for example, US patent No. 5 641 763 and 5 142 051.

Yale University and The University of Georgia Research Foundation, Inc. disclose the use of L-FDDC (5-fluoro-3'-thia-2'3'-dideoxycytidine) for the treatment of hepatitis B virus in WO 92/18517.

Other drugs used to treat HBV include adenosine arabinoside, thymosin, acyclovir, phosphonoformate, zidovudine, (+) cyanidanol, quinacrine, and 2'-fluoroarabinosyl-5-iodouracil.

US Patent Nos. 5,444,063 and 5,684,010 to Emory University disclose the use of enantiomerically pure β-D-1,3-dioxolanpurin nucleosides for the treatment of hepatitis B.

WO 96/40164, filed by Emory University, UAB Research Foundation and the Center National de la Recherche Scientifique, describes a series of β-L-2 ', 3'-dideoxynucleosides for the treatment of hepatitis B.

WO 95/07287, also filed by Emory University, UAB Research Foundation and the Center National de la Recherche Scientifique, discloses 2 'or 3' deoxy and 2 ', 3'-dideoxy-β-L-pentofuranosyl nucleosides for treating HIV infection.

WO 96/13512, filed by Genencor International, Inc., and Lipitek, Inc., describes the preparation of L-ribofuranosyl nucleosides as antitumor agents and viricides.

WO 95/32984 describes lipid esters of nucleoside monophosphates as immunosuppressive drugs.

DE 4224737 describes cytosine nucleosides and their pharmaceutical uses.

Tsai et al. at Biochem. Pharmacol 48 (7), pages 1477-81, 1994, describe the effect of 2'-β-D-F-2 ', 3'-dideoxynucleoside analogs of an anti-HIV agent on the cellular content of mitochondrial DNA and lactate production.

Galvez, J. Chem. Inf. Comput. Sci. (1994), 35 (5), 1198-203 describes a molecular count of β-D-3'-azido-2 ', 3'-dideoxy-5-fluorocytidine.

Mahmoudian, Pharm. Research 8 (1), 43-6 (1991) describes a quantitative structurally active linkage analysis of HIV agents, such as β-D-3'-azido-2 ', 3'-dideoxy-5-fluorocytidine.

US Patent No. 5,703,058 describes nucleosides (5-carboximido or 5-fluoro) - (2 ', 3'-unsaturated or 3'-modified) pyrimidine for the treatment of HIV or HBV.

Lin et al. in J. Med. Chem. 31 (2), 336-340 (1988) describe the synthesis and antiviral activity of 3'-azido analogs of β-D-nucleosides.

An essential step in the mode of action of purine and pyrimidine nucleosides against viral diseases, in particular HBV and HIV, is their metabolic activation by cellular and viral kinases to produce mono-, di- and triphosphate derivatives. The biologically active species of many nucleosides is the triphosphate form, which inhibits DNA polymerase or reverse transcriptase, or breaks the chain. Nucleoside derivatives developed to date for the treatment of HBV and HIV are presented for administration to the patient in a non-phosphorylated form, despite the fact that the nucleoside must be phosphorylated in the cell before it exhibits its antiviral effect, since the triphosphate form is usually dephosphorylated before it reaches the cell, otherwise, it is poorly absorbed by the cell. Nucleotides generally cross cell membranes with great difficulty and are usually not very effective in vitro. Attempts to modify nucleotides to increase their absorption and efficiency are described by R. Jones and N. Bischofberger, Antiviral Research, 27 (1995) 1-17.

Due to the fact that the hepatitis B virus has reached an epidemic level worldwide and has a strong, and often tragic, effect on an infected patient, there remains a great need for the development of new effective low-toxic pharmaceutical agents for treating people infected with the virus.

Therefore, it is an object of the present invention to provide compounds, compositions and methods for treating people or other patients infected with HBV.

SUMMARY OF THE INVENTION

A method is described for treating HBV infection in humans and other animals, comprising administering an effective amount of β-L- (2 'or 3'-azido) -2', 3'-dideoxy-5-fluorocytosine nucleoside or its pharmaceutically acceptable salt, ester or prodrugs, including stabilized phosphate, administered alone or in combination or alternately with another anti-HBV agent, optionally with a pharmaceutically acceptable carrier. According to a preferred embodiment of the present invention, the 2'- or 3'-azido group has a ribosyl configuration. In a preferred embodiment, the nucleoside is in the form of said enantiomer, essentially in the absence of its corresponding β-D enantiomer.

In accordance with one embodiment of the invention, the active compound is β-L- (2'-azido) -2 ', 3'-dideoxy-5-fluorocytosine (L-2'-A-5-FddC), or a pharmaceutically acceptable compound thereof an acceptable ester, salt or prodrug of the formula:

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative (to form a stabilized nucleotide prodrug), and R 'represents H, acyl or alkyl.

According to another embodiment of the present invention, the active compound is β-L- (3'-azido) -2 ', 3'-dideoxy-5-fluorocytosine (L-3'-A-5-FddC) or a pharmaceutically acceptable thereof ester, salt or prodrug of the formula:

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative (to obtain a stable nucleotide prodrug), and R 'represents H, acyl or alkyl.

The disclosed nucleosides, or their pharmaceutically acceptable prodrugs, esters or salts, or pharmaceutically acceptable formulations containing such compounds, can be used to prevent and treat HBV infections and the like, such as anti-HBV antibody-positive and HBV-positive conditions , chronic liver inflammation caused by HBV, cirrhosis, acute hepatitis, fulminant hepatitis, chronic persistent hepatitis and fatigue. Such compounds or compositions can also be used prophylactically to prevent or slow the progression of clinical disease in anti-HBV antibody or HBV-antigen-positive patients, or those in contact with HBV.

In accordance with one of its variants of implementation, the present invention includes a method of treating people infected with HBV, comprising administering the required amount of prodrug of specific L- (2 'or 3') - A-5-Fddc nucleosides necessary for the treatment of HBV. As used herein, the term “prodrug” refers to a pharmaceutically acceptable derivative of a specifically described nucleoside converted to a nucleoside when administered in vivo or having its own activity. Non-limiting examples are 5 'and N ⁴ -cytosine-acylated or alkylated derivatives of the active compound, as well as derivatives of 5'-monophosphate, diphosphate or triphosphate, other phosphates or stabilized nucleotide prodrugs, described in more detail below. For example, a nucleoside is present as monophosphate, diphosphate or triphosphate in a composition that protects the compound from dephosphorylation. Compositions include liposomes, lipospheres, microspheres, or nanospheres (of which the last three can target infected cells).

In accordance with one embodiment of the present invention, one or more active compounds are administered alternately or in combination with one or more other anti-HBV agents, providing an effective anti-HBV treatment. Examples of anti-HBV agents that can be used in alternating or combination therapy include, but are not limited to, cis-2-hydroxymethyl-5- (5-fluorocytosin-1-yl) -1,3-oxathiolane, preferably according to essentially in the form of a (-) - optical isomer (“FTC”, see WO 92/14743); (-) - enantiomer of cis-2-hydroxymethyl-5- (cytosin-1-yl) -1, 3-oxathiolane (3TC); β-D-1,3-dioxolanpurin nucleosides described in US Pat. Nos. 5,444,063 and 5,684,010, carbovir, interferon penciclovir and famciclovir.

Any alternation method that provides patient treatment may be used. Non-limiting examples of alternation schemes include 1-6 weeks of administration of an effective amount of an agent, and then 1-6 weeks of administration of an effective amount of a second anti-HBV agent. Combination therapy usually involves the simultaneous administration of an effective dose ratio of two or more anti-HBV agents.

Due to the fact that HBV is often found in patients who also have a positive response to an anti-HIV antibody or HIV antigen or are in contact with HIV, the active anti-HBV compounds described herein or their derivatives or prodrugs can be administered in appropriate circumstances in combination or alternately with anti-HIV substances.

In accordance with one embodiment of the present invention, the second antiviral agent for treating HIV is a reverse transcriptase inhibitor ("RTI"), which can be either a synthetic nucleoside ("NRTI") or a non-nucleoside compound ("NNRTI"), in accordance with as an alternative, in the case of HIV, the second (or third) antiviral agent may be a protease inhibitor. In other embodiments, the second (or third) compound may be a pyrophosphate analog or a fusion binding inhibitor. Resistance data collected in vitro and in vivo for many antiviral compounds are provided by Schinazi et al., Mutations in retroviral genes associated with drug resistance, International Antiviral News, Volume 1 (4), International Medical Press, 1996.

Preferred examples of antiviral agents that can be used in combination or alternately with the compounds described here for HBV therapy include 2-hydroxymethyl-5- (5-fluorocytosin-1-yl) -1,3-oxathiolane (FTC); (-) - enantiomer of 2-hydroxymethyl-5- (cytosin-1-yl) -1,3-oxathiolane (3TC); carbovir, acyclovir, interferon, L-FMAU and β-D-dioxolane nucleosides such as β-D-dioxolanyl-guanine (DXG), β-D-dioxolanyl-2,6-diaminopurine (DAPD) and β-D-dioxolanyl -6-chloropurine (ACP), L-FDDC β-fluoro-3'-thia-2 ', 3'-dideoxycytidine), L-enantiomers of 3'-fluoro-modified (3-2'-deoxyribonucleoside 5'-triphosphates, famciclovir, penciclovir, bis-Pom RMED (adefovir, dipivoxyl); lobucavir, ganciclovir and ribavarin.

Active anti-HBV agents can also be administered in combination with antibiotics, other antiviral compounds, antifungal agents, or other pharmaceutical agents administered to treat secondary infections.

Brief Description of the Figures

Figure 1 is an illustration of a general reaction scheme for the stereospecific synthesis of 3'-substituted β-L-dideoxynucleosides.

Figure 2 is an illustration of a general reaction scheme for the stereospecific synthesis of 2'-substituted β-L-dideoxy-nucleosides.

Figure 3 is an illustration of a method for producing β-L- (3'-azido) -2 ', 3'-dideoxy-5-fluorocytosine (L-3'-A-5-FddC).

Figure 4 is an illustration of a method for producing β-L- (2'-azido) -2 ', 3'-dideoxy-5-fluorocytosine (L-2'-A-5-FddC).

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the terms “substantially”, “substantially absent”, or “substantially free of” refer to a nucleoside composition comprising at least about 95%, preferably about 97, 98, 99, or 100% of one enantiomer specific nucleoside.

The term "alkyl" in this description, unless otherwise indicated, refers to a saturated straight, branched or cyclic, primary, secondary or tertiary hydrocarbon with C ₁ -C ₁₀ and specifically includes methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl , t-butyl, cyclobutyl, pentyl, cyclopentyl, isopentyl, neopentyl, hexyl, isohexyl, cyclohexyl, cyclohexylmethyl, 3-methylpentyl, 2,2-dimethylbutyl and 2,3-dimethylbutyl. The alkyl group may optionally be substituted with one or more residues selected from the group consisting of hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate or phosphonate, which are unprotected or protected properly, as is known to those skilled in the art, for example, as indicated by Greene et al., "Protective Groups in Organic Synthesis", John Wiley and Sons, Second. Edition., 1991. The term “lower alkyl” as used herein, unless otherwise indicated, refers to a C ₁ -C ₄ ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl or t-butyl group.

As used herein, the term “acyl” specifically includes, but is not limited to, C (O) alkyl, C (O) aryl, acetyl, propionyl, butyryl, pentanoyl, 3-methylbutyryl, hydrogen succinate, 3-chlorobenzoate, benzoyl, acetyl , pivaloyl, mesylate, propionyl, valeryl, caproic, caprylic, capric, lauric, myristic, palmitic, stearic and oleic or the remainder of the amino acid part.

The term “aryl” as used herein, unless otherwise indicated, refers to phenyl, biphenyl or naphthyl, preferably phenyl. The aryl group may optionally be substituted with one or more residues selected from the group consisting of hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate or phosphonate, which are unprotected or protected properly, as is known to those skilled in the art, for example, in accordance with the guidelines of Greene et al., "Protective Groups in Organic Synthesis", John Wiley and Sons, Second Edition, 1991.

As used herein, the term “amino acid” refers to naturally occurring and unnatural amino acids and includes, but is not limited to, alanyl, valinyl, leucinyl, isoleucinyl, proinyl, phenylalaniline, tryptophanyl, methioninyl, glycinyl, serynyl, threoninyl, cysteinyl, tyrosinyl, asparaginyl, glutmini , aspartoyl, glutaoyl, lysinyl, artininyl and histidinyl.

The term "prodrug" as used herein refers to a pharmaceutically acceptable derivative of the specifically described nucleoside convertible to nucleoside when administered in vivo or having intrinsic activity. Non-limiting examples are 5'- and N ⁴ -cytosinacylated or alkylated derivatives of the active compound, as well as 5'-monophosphate, diphosphate or triphosphate derivatives, other phosphates, or stabilized nucleotide prodrugs, or 5'-ether lipids, as described in detail below. For example, a nucleoside is present as monophosphate, diphosphate or triphosphate in a composition that protects the compound from dephosphorylation. Compositions include liposomes, lipospheres, microspheres or nanospheres (of which the last three can be targeted to infected cells).

The disclosed invention includes a method and composition for treating HBV infection and other similarly reproduced viruses in humans or other animals, comprising administering an effective amount of one or more of the above compounds or physiologically acceptable salts thereof, optionally with a pharmaceutically acceptable carrier, for treating HBV. The compounds of the present invention either have anti-HBV activity or are metabolized to the compound or compounds exhibiting anti-HBV activity.

The structure and preparation of active nucleosides

Stereochemistry

Since the 1 'and 4' carbon atoms of sugar (hereinafter generally referred to as the "sugar residue") of nucleosides are chiral, their non-hydrogen substituents (CH ₂ OR and the pyrimidine or purine base, respectively) can either have cis (on the same side) or trans configuration (on opposite sides) with respect to the sugar ring system. Therefore, the four optical isomers are represented by the following configurations (when the sugar residue is oriented in a horizontal plane so that the "primary" oxygen (between the C1 'and C4' atoms) is at the back): "β" or "cis" (when both groups are located " at the top ", which corresponds to the configuration of natural nucleosides, ie the D-configuration)," β "or cis (when both groups are located" below ", which is an unnatural configuration, i.e. the L-configuration)," α "or “trans” (when Deputy C2 is located “above” and Deputy C5 is “below”), and akzhe "α" or trans (C2 when the substituent is "down" and the C5 substituent - "up").

Active nucleosides in accordance with the present invention have a β-L configuration, wherein the azido group has a ribosyl configuration.

Prodrug Formulations

The nucleosides described herein can be introduced in the form of any derivative that, after administration to the recipient, is able to directly or indirectly form an active parent compound or exhibits its own activity. According to one embodiment of the present invention, the hydrogen of the 5'-OH groups is substituted with C ₁ -C ₂₀ alkyl; an acyl comprising such an acyl in which the non-carbonyl radical of the ester group is selected from straight, branched or cyclic C ₁ -C ₂₀ alkyl, phenyl or benzyl; natural or unnatural amino acid; 5'-ester lipid or 5'-complex phosphoether ester lipid; alkoxyalkyl including methoxymethyl; aralkyl, including benzyl; aryloxyalkyl such as phenoxymethyl; aryl including phenyl optionally substituted with halogen, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy; a dicarboxylic acid such as succinic acid; sulfonate esters such as alkyl or aralkylsulfonyl, including methanesulfonyl; or mono-, di- or triphosphate ether.

One or both hydrogens of amino groups on a purine or pyrimidine base may be substituted with C ₁ -C ₂₀ alkyl; acyl in which the non-carbonyl residue of the ester group is selected from straight, branched or cyclic C ₁ -C ₂₀ alkyl, phenyl or benzyl; alkoxyalkyl, including methoxymethyl; aralkyl, including benzyl; aryloxyalkyl such as phenoxymethyl; aryl, including phenyl, optionally substituted with halogen, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy.

The active nucleoside may also be in the form of a 5 'ester lipid, as described in the following references: Kucera, LS, N. lyer, E. Leake, A. Raben, Modest EJ, DLW, and C. Piantadosi, 1990. Novel membrane - interactive ether lipid analogs that inhibit infectious HIV-1 production and induce defective virus formation. AIDS Res Hum Retroviruses. 6: 491-501; Piantadosi, C., J. Marasco C.J., S.L. Morris-Natschke, K.L. Meyer, F. Gumus, J.R. Surles, K.S. Ishaq, L.S. Kucera, N. lyer, C.A. Wallen, S. Piantadosi, and E.J. Modest, 1991. Synthesis and evaluation of novel ether lipid nucleoside conjugates for anti-HIV activity. J. Med. Chem. 34: 1408.1414; Hostetler, K.Y., D.D. Richman, D.A. Carson, L.M. Stuhmiller, G.M. T. van Wijk, and H. van den Bosch. 1992. Greatly enhanced inhibition of human immunodeficiency virus type 1 replication in CEM and HT4-6C cells by 3'-deoxythymidine diphosphate dimyristoylglycerol, a lipid prodrug of 3'-deoxythymidine. Antimicrob Agents Chemother. 36: 2025.2029; Hostetler, K.Y., L.M. Stuhmiller, H.B. Lenting, H. van den Bosch, and D.D. Richman, 1990. Synthesis and antiretroviral activity of phospholipid analogs of azidothymidine and other antiviral nucleosides. J. Biol.

Chem. 265: 6112.7.

Stabilized Nucleotides

Any nucleosides described herein can be introduced as a nucleotide prodrug or phospholipid prodrug to increase activity, bioavailability, resistance, or any other change in the properties of the nucleoside. The number of ligands of the nucleotide prodrug is known. In general, alkylation, acylation, or another lipophilic modification of a mono-, di-, or triphosphate nucleoside enhances the resistance of the nucleotide. Examples of substituent groups which may replace one or more hydrogen atoms in the phosphate residue are alkyl, aryl, steroids, carbohydrates, including sugars, 1,2-diacylglycerol and alcohols. Many of them are described by B. Jones and H. Bischofberger, Antiviral Research, 27 (1995) 1-17. Any of them can be used in combination with the described nucleosides to obtain the desired effect. Non-limiting examples of nucleotide prodrugs are described in the following references: But, D.H.W. (1973) Distribution of Kinase and deaminase of Ib-D-arabinofuranosylcytosine in tissues of man and muse. Cancer Res. 33.2816-2820; Holy, A. (1993) Isopolar phosphorous-modified nucleotide analogues. In: De Clercq (Ed.), Advances in Antiviral Drug Design, Vol. I, JAI Press, pp. 179-231; Hong, C.I., Nechaev, A., and West, C.R. (1979a) Synthesis and antitumor activity of Ib-D-arabinofuranosylcytosine conjugates of cortisol and cortisone. Biochem. Biophys. Rs. Commun. 88.1223-1229; Hong, C.I., Nechaev, A., Kirisits, A.J. Buchheit, D.J. and West, C.R. (1980) Nucleoside conjugates as potential antitumor agents. 3. Synthesis and antitumor activity of l- (b-D-arabinofuranosyl) cytosine conjugates of corticosteriods and selected lipophilic alcohols. J. Med. Chem. 28.171-177; Hostetler, K.Y. Stuhmiller, L.M., Lenting, H.B.M. van den Bosch, H. and Richman, D.D. (1990) Synthesis and antiretrioviral activity of phospholipid analogs of azidothymidine and other antiviral nucleosides. J. Biol. Chem. 265, 6112-6117; Hostetler, K..Y., Carson, D.A. and Richman, D.D. (1991); Phosphatidylazidothymidine: mechanism of antiretroviral action in CEM cells. J. Biol. Chem. 266, 11714-11717; Hostetler, K.Y., Korba, B. Sridhar, C., Gardener, M. (1994a) Antiviral activity of phosphatidyl-dideoxycytidine in hepatitis B-infected cells and enhanced hepatic uptake in mice. Antiviral Res. 24, 59-67; Hostetler, K.Y., Richman, D.D., Sridhar, C.N. Felgner, P. L., Felgner, J., Ricci, J., Gardener, M.F. Selleseth, D.W. and Ellis, M.N. (1994b) Phosphatidylazidothymidine and phosphatidyl-ddC: Assessment of uptake in mouse lymphoid tissues and antiviral activities in human immunodeficiency virus-infected cells and in rauscher leukemia virus-infected mice. Antimicrobial Agents Chemolher. 38, 2792-2797; Hunston, R.N., Jones, A.A. McGuigan, C., Walker, R.T., Balzarini, J., and De Clercq, E. (1984) Synthesis and biological properties of some cyclic phosphotrieslers derived from 2'-deoxy-5-fluorouridine. J. Med. Chem. 27, 440-444; Ji, Y. H., Moog, C., Schmitt, G., Bischoff, P. and Luu, B. (1990); Monophosphoric acid diesters of 7b-hydroxycholesterol and of pyrimidine nucleosides as potential antitumor agents: synthesis and preliminary evaluation of antitumor activity. J. Med. Chem. 33, 2264-2270; Jones, A.S. McGuigan, C., Walker, R.T. Balzarini, J. and DeClercq, E. (1984) Synthesis, properties, and biological activity of some nucleoside cyclic phosphoramidates. J.

Chem. Soc. Perkin Trans. I, 1471-1474; Juodka, B.A. and Smrt, J. (1974) Synthesis of ditribonucleoside phosph (P®N) amino acid derivatives. Coll. Czech Chem. Comm. 39, 363-968; Kataoka, S., Imai, J., Yamaji, N., Kato, M., Saito, M., Kawada, T. and Imai, S. (1989) Alkylacted cAMP derivatives; selective synthesis and biological activities. Nucleic Acids Res. Sym. Ser., 21, 1-2; Kataoka, S., Uchida, R. and Yamaji, N. (1991) A convenient synthesis of adenosine 3 ', 5'cyclic phosphate (cAMP) benzyl and methyl triesters. Heterocycles 32, 1351-1356; Kinchington, D., Harvey, J.J., O'Connor, T.J., Jones, B.C.N.M., Devine, K.G., Taylor-Robinson, D., Jeffries, D.J. and McGuigan, C. (1992) Comparison of antiviral effects of zidovudine phosphoramidate and phosphorodiamidate derivatives against HIV and ULV in vitro. Antiviral Chem. Chemother. 3.107-112; Kodama, K., Morozumi, M., Saitoh, K.I., Kuninaka, H., Yoshino, H. and Saneyoshi, M. (1989) Antitumor activity and pharmacology of 1-b-D-arabinofuranosylcytosine-5'-stearylphosphate; an orally active derivative of 1-b-D-arabinofuranosylcytosine. Jpn. J. Cancer Res. 80, 679-685; Korty, M. and Engels, J. (1979) The effects ofadenosine- and guanosine 3 ', 5'phosphoric and acid benzyl esters on guinea-pig ventricular myocardium. Naunyn-Schmiedeberg's Arch. Pharmacol 310, 103-111; Kumar, A., Goe, P. L., Jones, A.S. Walker, R.T. Balzarini, J. and De Clercq, E. (1990) Synthesis and biological evaluation of some cyclic phosphoramidate nucleoside derivatives. J. Med. Chem. 33.2368-2375; LeBec, C., and Huynh-Dinh, T. (1991) Synthesis of lipophilic phosphate triester derivatives of 5-fluorouridine and arabinocytidine as anticancer prodrugs. Tetrahedron Lett. 32.6553-6556; Lichtenstein, J., Bamer, H.D. and Cohen, S.S. (I960) The metabolism of exogenously supplied nucleotides by Escherichia co! I „J. Biol. Chem. 235, 457-465; Lucthy, J., Von Daeniken, A., Friederich, J. Manthey, B., Zweifel, J., Schlatter, C. and Benn, M.H. (1981) Synthesis and toxicological properties of three naturally occurring cyanoepithioalkanes. Mitt. Geg. Lebensmittelunters. Hyg. 72,131-133 (Chem. Abstr. 95,127093); McGuigan, C. Tollerfield, S.M. and Riley, P.A. (1989) Synthesis and biological evaluation of some phosphate triester derivatives of the antiviral drug Ara. Nucleic Acids Res. 17.6065-6075; McGuigan, C., Devine, K.G., O'Connor, T.J., Galpin, S.A. “Jeffries, D.J. and Kinchington, D. (1990a) Synthesis and evaluation of some novel phosphoramidate derivatives of3'-azido-3'-deoxythymidine (AZT) as ani-HIV compounds. Antiviral Chem. Chemother. 1.107-113; McGuigan, C., O'Connor, T.J., Nicholls, S.R. Nickson, C. and Kinchington, D. (1990b) Synthesis and anti-HIV activity of some novel substituted dialky phosphate derivatives of AZT and ddCyd. Antiviral Chem. Chemother. 1, 355-360; McGuigan, S., Nicholls, S.R., O'Connor, T.J., and Kinchingion, D. (1990c) Synthesis of some novel dialkyi phosphate derivative of 3'-modified nucleosides as potential anti-AIDS drugs. Antiviral Chem. Chemother. 1, 25-33; McGuigan, C., Devine, K..G., O'Connor, TJ, and Kinchington, D. (1991) Synthesis and anti-HIV activity of some haloalky phosphoramidate derivatives of 3'-azido-3'deoxythylmidine (AZT) ; potent activity of the trichloroethyl methoxyalaninyl compound. Antiviral Res. 15,255-263; McGuigan, C., Pathirana, R.N., Mahmood, N., Devine, K.G. and Hay, A.J. (1992) Aryl phosphate derivatives of AZT retain activity against HIV1 in cell lines which are resistant to the action of AZT. Antiviral Res. 17, 311-321; McGuigan, C., Pathirana, R.N., Choi, S.M., Kinchington, D. and O'Connor, T.J. (1993a) Phosphoramidate derivatives of AZT as inhibitors ofHIV; studies on the carboxyl terminus. Antiviral Chem. Chemother. 4, 97-101; McGuigan, C., Pathirana, R.N., Balzarini, J. and De Clercq, E. (1993b) Intracellular delivery ofbioactive AZT nucleotides by aryl phosphate derivatives of AZT. J. Med. Chem. 36, 1048-1052.

Derivatives of the alkyl hydrophosphonate of the anti-HIV agent AZT may be less toxic than the parent nucleoside analogue.

Antiviral Chem. Chemother. 5.271-277; Meyer, R. B., Jr., Shuman, DA and Robins, RK (1973) Synthesis of purine nucleoside 3 ', 5'-cyclic phosphoramidates. Tetrahedron Lett. 269-272; Nagyvary, J. Gohil, RN, Kirchner, CR and Stevens, JD (1973) Studies on neutral esters of cyclic AMP, Biochem. Biophys. Res. Commun. 55, 1072-1077; Namane, A. Gouyette, C., Fillion, MP, Fillion, G. and Huynh-Dinh, T. (1992) Improved brain delivery of AZT using a glycosyi phosphotriester prodrug. J. Med. Chem. 35, 3039-3044; Nargeot, J. Nerbonne, JM Engels, J. and Leser, HA (1983) Natl. Acad. Sci. USA 80,2395-2399; Nelson, KA, Bentrude, WG, Stser, WN and Hutchinson, JP (1987) The question of chair-twist equilibria for the phosphate rings of nucleoside cyclic 3 ', 5'monophosphates. 'HNMR and x-ray crystallographic study of the diasteromers of thymidine phenyl cyclic 3', 5'-monophosphate. J. Am. Chem. Soc. 109, 4058-4064; Nerbonne, JM, Richard, S., Nargeot, J. and Lester, HA (1984) New photoactivatable cyclic nucleotides produce intracellular jumps in cyclic AMP and cyclic GMP concentrations. Nature 301, 74-76; Neumann, JM, Herve, M., Debouzy, JC, Guerra, FI, Gouyette, C., Dupraz. B. and Huynh-Dinh, T. (1989) Synthesis and transmembrane transport studies by NMR of aglucosyi phospholipid of thymidine. J. Am. Chem. Soc. Ill, 4270-4277; Ohno, R., Tatsumi, N .. Hirano, M., Imai, K. Mizoguchi, H., Nakamura, T., Kosaka, M, Takatuski, K., Yamaya, T., Toyama, K., Yoshida, T., Masaoka, T., Hashimoto, S., Ohshima, T., Kimura, I., Yamada, K. and Kimura, J. (1991) Treatment of myelodysplastic syndromes with orally administered 1-bD-rabinofuranosylcytosine -5 ' stearylphosphate. Oncology 48,451-455. Palomino, E., Kessle, D. and Horwitz, JP (1989) A dihydropyridine carrier system for sustained delivery of 2 ', 3'dideoxynucleosides to the brain. J. Med. Chem. 32,622-625; Perkins, RM, Barney, S., Wittrock, R., Clark, PH, Levin, R. Lambert, DM, Petteway, SR, Serafinowska, HT, Bailey, SM „Jackson, S., Harnden, MR Ashton, R. , Sutton. D., Harvey, JJ and Brown, AG (1993) Activity of BRL47923 and its oral prodrug, SB203657A against a rauscher murine leukemia virus infection in mice. Antiviral Res. 20 (Suppl. I). 84; Piantadosi, C., Marasco, CJ, Jr., Morris-Natschke, SL, Meyer, KL, Gumus, F., Surles, JR, Ishaq, KS, Kucera, LS lyer, N., Wallen, CA, Piantadosi, S . and Modest, EJ (1991) Synthesis and evaluation of novel ether lipid nucleoside conjugates for anti-HIV-1 activity. J. Med. Chem. 34.1408-1414; Pompon, A., Lefebvre, I., Imbach, JL, Kahn, S. and Farquhar, D. (1994) Decomposition pathways of the mono- and bis (pivaloyloxymethyl) esters of azidothymidine-5'-monophosphate in cell extract and in tissue culture medium; an application of the on-line ISRP-cleaning 'HPLC technique. Antiviral Chem. Chemother. 5.91-98; Postemark, T. (1974) Cyclic AMP and cyclic GMP. Annu. Rev. Pharmacol 14.23-33; Prisbe, EJ, Martin, JCM, McGee, DPC, Barker, MF, Smee, DF Duke, AE, Matthews, TR and Verheyden, JPJ (1986) Synthesis and antiherpes virus activity of phosphate an phosphonate derivatives of 9 - [(l, 3-dihydroxy-2-propoxy) memyl] guanine. J. Med. Chem. 29, 671-675; Pucch, F., Gosselin, G., Lefebvre, I., Pompon, A., Aubertin, AM Dirn, A. and Imbach, JL (1993) Intracellular delivery of nucleoside monophosphate through a reductase-mediated activation process. Antiviral Res. 22.155-174; Pugaeva, VP, Klochkeva, SI, Mashbits, FD and Eizengart, RS (1969). Toxicological assessment and health standard ratings for ethylene sulfide in the industrial atmosphere. Gig. Trf. Prof. Zabol. 13.47-48 (Chem. Abstr. 72.212); Robins, RK (1984) The potential of nucleotide analogs as inhibitors of retroviruses and tumors. Pharm. Res. 11-18; Rosowsky, A., Kirn. SH, Ross and J. Wick, MM (1982) Lipophilic 5 '- (alkylphosphate) esters of lbD-arabinofuranosylcytosine and its N ⁴ -acyl and 2.2'-anhydro-3'0-acyl derivatives as potential prodrugs. J. Med. Chem. 25.171-178; Ross, W. (1961) Increased sensitivity of the walker turnout towards aromatic nitrogen mustards carrying basic side chains following glucose pretreatment. Biochem. Pharm. 8.235-240; Ryu, eK, Ross, RJ Matsushita, T., MacCoss, M., Hong, CI and West, CR (1982). Phospholipidnucleoside conjugates. 3. Synthesis and preliminary biological evaluation of 1-bD-arabinofuranosylcytosine 5'diphosphate [-], 2-diacylglycerols. J. Med. Chem. 25, 1322-1329; Saffhill, R. and Hume, WJ (1986) The degradation of 5-iododeoxyurindine and 5-bromoeoxyuridine by serin from different sources and its consequences for the use of these compounds for incorporation into DNA. Chem. Biol. Interact 57, 347-355; Saneyoshi, M., Morozumi, M., Kodama, K., Machida, J., Kuninaka, A. and Yoshino, H. (1980) Synthetic nucleosides and nucleotides. Xvi. Synthesis and biological evaluations of a series of 1-bD-arabinofuranosylcytosine 5'-alky or arylphosphates. Chem. Pharm. Bull. 28, 2915-2923; Sastry, JK, Nehete, PN, Khan, S., Nowak, BJ, Plunkett, W., Arlinghaus, RB and Farquhar, D. (1992) Membrane-permeable dideoxyuridine 5'-monophosphate analogue inhibits human immunodeficiency virus infection. Mol. Pharmacol 41,441-445; Shaw, JP, Jones, RJ Arimilli, MN, Louie, MS, Lee, WA and Cundy, KC (1994) Oral bioavailability of PMEA from PMEA prodrugs in male Sprague-Dawley rats. 9th Annual AAPS Meeting. San Diego, CA (Abstract). Shuto, S., Ueda, S., Imamura, S., Fukukawa, K. Matsuda, A. and Ueda, T. (1987) A facile one-step synthesis of 5'phosphatidylnucleosides by an enzymatic two-phase reaction. Tetrahedron Lett. 28,199-202; Shuto, S., Itoh, H., Ueda, S., Imamura, S., Kukukawa, K., Tsujino, M., Matsuda, A. and Ueda, T. (1988) A facile enzymatic synthesis of 5'- (3-sn-phosphatidyl) nucleosides and their antileukemic activities. Chem. Pharm. Bull. 36,209-217.

A preferred phosphate group of the prodrug is the 3-acyl-2-thioethyl group, also referred to as “SATE”.

Obtaining active compounds

Nucleosides used in the described method for the treatment of HBV infections in the host organism can be obtained in accordance with known methods. The general process for the stereospecific synthesis of 3'-substituted β-L-dideoxynucleosides is shown in Figure 1. The general process for the stereospecific synthesis of 2'-substituted β-L-dideoxynucleosides is shown in Figure 2. Detailed synthesis of β-L- (3'-azido) -2 ', 3'-dideoxy) -5-fluorocytosine is shown in figure 3. A detailed synthesis of [3-L- (2'-azido) -2', 3'-dideoxy) -5-fluorocytosine is shown in figure 4 and below in the example 2.

Example 1

Preparation of β-L- (3'-azido) -2 ', 3'-dideoxy-5-fluorocytosine

The melting point is determined in open capillary tubes on a Gallenkamp MFB-595-010 M instrument and is not corrected. The UV absorption spectrum is recorded on a Uvikon 931 spectrophotometer (KONTRON) in ethanol. ¹ H-NMR spectrum was determined at room temperature in DMSO-d ₆ on a Bruker AC 250 or 400 spectrometer. Chemical shifts are given in ppm, while DMSO-d _{5 was} set to 2.49 ppm. as a standard. Deutero exchange, fission experiments or 2D-COZY are carried out in order to confirm the separation of protons. Multiplet signals are represented by s (singlet), d (doublet), dd (doublet of doublets), t (triplet), q (quadruplet), br (wide), m (multiplet). All values of J are indicated in Hz. The FAB mass spectrum was recorded as positive (FAB> 0) or negative (FAB <0) ions on a JEOL DX 300 mass spectrometer. The matrix is 3-nitrobenzyl alcohol (NBA) or a mixture (50:50 v / v ) glycerol and thioglycerol (GT). The specific rotation is measured on a Perkin-Elmer 241 spectropolarimeter (step length 1 cm) and is indicated in units of 10 ^-1 degrees. cm ² g ^-1 . Elemental analysis was performed by Service de Microanalyses du CNRS, Division de Vemaison (France). Analyzes indicated by symbols of elements or functions make up ± 0.4% of theoretical values. Silica Gel 60 F ₂₅₄ (Merck, Art. 5554) pre-coated aluminum sheets were used for thin-layer chromatography; the products were visualized using UV absorption followed by carbonization with 10% ethanol sulfuric acid and heating. Column chromatography was performed on Silica Gel 60 (Merck, Art. 9385) at atmospheric pressure.

1- (2-O-Acetyl-3,5-di-0-benzoyl-β-L-xylofuranosyl) -5-fluorouracil (2)

A suspension of 5-fluorouracil (5.0 g, 38.4 mmol) was treated with hexamethyldisilazane (HMDS, 260 ml) and a catalytic amount of ammonium sulfate for 18 hours under reflux. After cooling to room temperature, the mixture was evaporated under reduced pressure, and the residue obtained as a colorless oil was diluted with anhydrous 1,2-dichloroethane (260 ml). To the resulting solution was added 1,2-di-O-acetyl-3,5-di-O-benzoyl-L-xylofuranose 1 (11.3 g, 25.6 mmol.) [See: Gosselin, G .; Bergogne, M. - C; Imbach, J .-. L., "Synthesis and Antiviral Evaluation of β-L-Xylofuranosyl Nucleotides of the Five Naturally Occuring Nucleic Acid Bases", Journal of Heterocyclic Chemistry, 1993, 30 (Oct.-Nov.), 1229-1233 ] in anhydrous 1,2-dichloroethane (130 ml) followed by the addition of trimethylsilyl trifluoromethanesulfonate (TMSTf, 9.3 ml, 51.15 mmol). The solution was stirred for 6 hours at room temperature under argon, then diluted with chloroform (1 L), washed with the same volume of a saturated aqueous solution of sodium bicarbonate, and finally with water (2 × 800 ml). The organic phase is dried over sodium sulfate and then evaporated under reduced pressure. The resulting crude material was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-4%) in methylene chloride] to give compound 2 (11.0 g, 84% yield) as a white foam; mp = 96-98 ° C; UV (ethanol): λ _max = 228 hm (ε = 25900) 266 nm (ε = 9000), λ _min = 250 nm (ε = 7200); ¹ H-NMR (DMSO-d ₆ ): δ 11.1 (br s, 1H, NH), 8.05 (1H, H-6, J _6-FS = 6.8 Hz), 7.9-7 4 (m, 10H, 2 С ₆ Н ₅ СО), 5.99 (d, 1H, Н-1 ', J _1'-2' = 3.1 Hz), 5.74 (dd, 1H, H -3 ', J _3'-2' = 4.2 Hz and J _{3'-4 '} = 2.3 Hz), 5.54 (t, 1H, H-2', J _{2'-1 '} = J _{2'-3 '} = 2.9 Hz), 4.8-4.6 (m, 3H, H-4', H-5 'and H-5 "); MS: FAB> 0 (GT matrix) m / z 513 (M + H) ⁺ , 383 (S) ⁺ 105 (C ₆ H ₅ CO) ⁺ ; FAB <0 (matrix GT) m / z 511 (MH) ^- , 469 (M-CH ₃ CO) ^- 129 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -91 (s, 0.88 DMSO); Anal. C ₂₅ H ₂₁ FN ₂ O ₉ (C, H, N, F).

1- (3,5-Di-O-benzoyl-β-L-xylofuranosyl) -5-fluorouracil 3

Hydrazine hydrate (2.80 ml, 57.4 mmol) was added to a solution of 1- (2-O-acetyl-3,5-di-O-benzoyl-β-L-xylofuranosyl) -5-fluorouracil 2 (9.80 g , 19.1 mmol) in acetic acid (35 ml) and pyridine (150 ml). The resulting solution was stirred overnight at room temperature. Acetone (50 ml) was added and the mixture was stirred for 2 hours. The reaction mixture was concentrated to a small volume and partitioned between ethyl acetate (200 ml) and water (200 ml). The layers were separated and the organic phase was washed with saturated aqueous sodium bicarbonate (2 × 200 ml) and finally with water (2 × 200 ml). The organic phase is dried over sodium sulfate and then evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-5%) in methylene chloride] to obtain pure compound 3 (7.82 g, 87%), each crystallized from methylene chloride; mp = 93-97 ° C;

UV (ethanol): λ _max. = 227 nm (ε = 22800) 267 nm (ε = 8200), λ _min = 249 nm (ε = 5900); ¹ H-NMR (DMSO-d ₆ ): δ 11.9 (br s, 1H, NH), 8.06 (d, 1H, H-6, J _6-F5 = 6.9 Hz), 8.0 -7.4 (m, 10 H, 2 C ₆ H ₅ CO), 6.35 (d, 1H, OH-2 ', J _OH-2' = 3.8 Hz), 5.77 (d, 1H , H-1 ', J _1'-2' = 3.3 Hz), 5.43 (dd, 1H, H-3 ', J _3'-2' = 3.1 Hz and J _{3'-4 '} = 1.9 Hz), 4.8-4.6 (m, 3H, H-4 ', H-5' and H-5 "), 4.43 (t, 1H, H-2 ', J = 2.3 Hz); MS: FAB> 0 (GT matrix) m / z 941 (2M + H) ⁺ , 471 (M + H) ⁺ , 341 (S) ⁺ 131 (BH ₂ ) ⁺ , 105 (C ₆ H ₅ CO) ⁺ ; FAB <0 (matrix GT) m / z 939 (2M-H) ^- , 469 (M-H) ^- , 129 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- ; [ α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -110 (s, 1.55 DMSO).

1- (2-Deoxy-3,5-di-O-benzoyl-β-L-threo-pentofuranosyl) -5-fluorouracil 5

To a solution of 1- (3,5-di-O-benzoyl-β-L-xylofuranosyl) -5-fluorouracil 3 (15.4 g, 32.7 mmol) in anhydrous acetonitrile (650 ml) was added O-phenyl chlorothioformate ( 6.80 ml, 49.1 mmol) and 4-dimethylaminopyridine (DMAP, 12.0 g, 98.2 mmol). The resulting solution was stirred at room temperature under argon for 1 h, and then evaporated under reduced pressure. The residue was dissolved in methylene chloride (350 ml) and the organic solution was washed successively with water (2 × 250 ml), ice-cold 0.5 N hydrochloric acid (250 ml) and water (2 × 250 ml), dried over sodium sulfate and evaporated under reduced pressure. The crude material 4 is evaporated several times with anhydrous dioxane and dissolved in this solvent (265 ml). To the resulting solution, tris (trimethylsilyl) -silanhydride (12.1 ml, 39.3 mmol) and α, α'-azoisobutyronitrile (AIBH, 1.74 g, 10.8 mmol) are added under argon atmosphere. The reaction mixture is heated and stirred at 100 ° C. for 2.5 hours under argon, and then cooled to room temperature and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-2%) in chloroform] to obtain pure compound 5 (13.0 g, 87%), crystallized from diethyl ether / methanol; mp = 182-184 ° C; UV (ethanol): λ _max = 229 nm (ε = 25800), 269 nm (ε = 9300), λ _min = 251 nm (ε = 6500); ¹ H-NMR (DMSO-d ₆ ): δ 11.8 (br s, 1H, NH), 8.05 (d, 1H, H-6, J _6-F5 = 7.0 Hz), 8.0 -7.4 (m, 10 H, 2 С ₆ Н ₅ СО), 6.15 (d, 1H, Н-1 ', J _1'-2' = 7.4 Hz), 5.68 (t, 1H, H-3 ', J _3'-2' = J _{3'-4 '} = 4.2 Hz), 4.8-4.6 (m, 2H, H-5' and H "-5), 4.6 (m, 1H, H-4 '), 3.0-2.8 (m, 1H, H-2'), 2.5-2.3 (d, 1H, H-2 "J = 14.8 Hz); MS: FAB> 0 (GT matrix) m / z 455 (M + H) ⁺ , 325 (S) ⁺ , 131 (BH ₂ ) ⁺ , 105

(C ₆ H ₅ CO) ⁺ ; FAB <0 (matrix GT) m / z 452 (M-H) ^- , 129 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -125 (from 1.05 DMSO); Anal. C ₂₃ H ₁₉ FN ₂ O ₇ (C, H, N, F).

1- (2-Deoxy-3,5-di-o-benzoyl-β-L-threo-pentofuranosyl) -4-thio-5-fluorouracil 6

Lawesson's reagent (3.1 g, 7, 70 mmol) was added under argon to a solution of compound 5 (5.0 g, 11.0 mmol.) In anhydrous 1,2-dichloroethane (200 ml) and the reaction mixture stirred overnight under reflux. Then, the solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-2%) in chloroform] to obtain 4-thio intermediate compound 6 (80% yield) as a yellow foam; mp = 178-179 ° C; UV (ethanol): _λmax = 230 nm (ε = 24900), 273 nm (ε = 6900), 333 nm (ε = 19200), λ _min = 258 nm (ε = 5900), 289 nm (ε = 5300) ; ¹ H-NMR (DMSO-d ₆ ): δ 13.1 (br s, 1H, NH), 8.10 (d, 1H, H-6, J _6-F5 = 4.6 Hz), 8.1 -7.4 (m, 10H, 2C ₆ H ₅ CO), 6.09 (d, 1H, H-1 ', J _1'-2' = 7.3 Hz), 5.68 (t, 1H, H-3 ', J _3'-2' = J _{3'-4 '} = 4.1 Hz), 4.9-4.8 (m, 2H, H-5' and H-5 "), 4, 7 (m, 1 H, H-4 '), 2.9 (m, 1 H, H-2'), 2.5 (m, 1H, H-2 "); MS: FAB> 0 (GT matrix) m / z 941 (2M + H) ⁺ , 471 (M + H) ⁺ , 325 (S) ⁺ , 147 (BH ₂ ) ⁺ , 105 (C ₆ H ₅ CO) ⁺ ; FAB <0 (matrix GT) m / z 469 (M-H) ^- , 145 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -271 (s, 0.90 DMSO); Anal. C ₂₃ H ₁₉ FN ₂ O ₆ S (C, H, N, F).

1- (2-Deoxy-β-L-threo-pentofuranosyl) -5-fluorocytosine 7

A solution of 4-thio-intermediate 6 (1.0 g, 2.13 mmol) in methanol ammonia (pre-saturated at -10 ° C and tightly corked) (60 ml) is heated at 100 ° C in a stainless steel reactor for 3 hours and then cooled to 0 ° C. The solution was evaporated to dryness under reduced pressure, and the residue was evaporated several times with methanol. The crude material is dissolved in water and the resulting solution is washed four times with methylene chloride. The aqueous layer was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (3-20%) in methylene chloride]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and filtered through a Millex HV-4 unit (0.45 μm, Millipore) to give 0.44 g of compound 7 (84% yield), crystallized from ethyl acetate / methanol; mp = 199-201 ° 0; UV (ethanol): λ _max = 226 nm (ε = 7700), 281 nm (ε = 8500), λ _min = 262 nm (ε = 6300); ¹ H-NMR (DMSO-d ₆ ): δ 7.99 (d, 1H, H-6, J _6-F5 = 7.4 Hz), 7.7-7.4 (br d, 2H, NHg) 5.98 (d, 1H, H-1 ', J _1'-2' = 8.1 Hz), 5.25 (d, 1H, OH-3 ', J _OH-3' = 3.4 Hz ), 4.71 (t, 1H, OH-5 ', J _OH-5' = J _{OH-5 "} = 5.6 Hz), 4.2 (m, 1H, H-3 '), 3.8-3 6 (m, 3H, H-4 ', H-5' and H-5 ''), 2.5 (m, 1H, H-2 '), 1.8 (m, 1H, H-2``); MS : FAB> 0 (GT matrix) m / z 491 (2M + H) ⁺ , 246 (M + H) ⁺ , 130 (BH ₂ ) ⁺ , FAB <0 (GT matrix) m / z 489 (2M-H) ^- , 244 (MH) ^- , 128 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -21 (s, 0.92 DMSO); Anal C ₉ H ₁₂ FN ₃ O ₄ (C, H, N, F).

1- (2-Deoxy-5-O-t-butyldimethyl silyl-β-L-threo-pentofuranoyl) -5-flucytosine 8

To a solution of compound 7_ (1.69 g, 6.89 mmol) in dry pyridine (35 ml), t-butyldimethylsilyl chloride (1.35 g, 8.96 mmol) was added dropwise and the mixture was stirred for 5 hours at room temperature. The mixture was then poured into saturated aqueous sodium bicarbonate (100 ml) and extracted with chloroform (3 × 150 ml). The combined extracts were washed with water (2 × 200 ml) and then dried over sodium sulfate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (2-10%) in methylene chloride] to obtain pure compound 8 (2.94 g, 87%) as a white solid: mp = 177- 179 ° C; UV (ethanol): λ _max = 241 nm (ε 9900), 282 nm (ε 10000), λ _min 226 nm (ε 8200), 263 nm (ε 7600); ¹ H NMR (DMSO-d ₆ ): δ 7.95 (d, 1H, H-6, J _6-F5 = 7.3 Hz), 7.8-7.3 (br d, 2H, NH ₂ ) 6.00 (dd, 1H, H-1 ', J _1'-2' = 6.1 Hz and J _{1'-2 "} = 1.9 Hz), 5.3 (br s, 1H, OH- 3 '), 4.2 (br s, 1H, H-3'), 3.9-3.7 (m, 3H, H-4 ', H-5' and H-5``), 2, 5 (m, 1H, H-2 '), 1.81 (br d, 1H, H-2 ", J = 14.6 Hz), 0.86 (s, 9H, (CH ₃ ) ₃ C-Si ), 0.05 (s, 6H, (CH ₃ ) ₂ Si); MS (GT matrix): FAB> 0 m / z 719 (2M + H) ⁺ , 360 (M + H) ⁺ , 130 (BH ₂ ) ⁺ . 115 (TBDMS) ⁺ ; FAB <0 m / z 717 (2M-H) ^- , 358 (MH) ^- , 128 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -23 (s, 0.96 DMSO).

1- (2-Deoxy-3-O-mesyl-5-O-t-butyldimethylsilyl-β-L-threo-pentofuranosyl) -5-fluorocytosine 9

A suspension of compound 8 (0.70 g, 1.96 mmol) in dry pyridine (30 ml) was stirred under argon atmosphere and cooled to 0 ° C. Methanesulfonyl chloride (MsCl 0.46 ml, 5.88 mmol.) Was added dropwise and the reaction mixture was stirred at 0 ° C for 5 hours. Then, the mixture was poured into ice water (100 ml) and extracted with chloroform (3 × 100 ml). The combined extracts were washed with 5% aqueous sodium bicarbonate (100 ml), water (2 × 100 ml), dried over sodium sulfate and evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (8-12%,) in toluene] to give pure compound 9 (0.56 g 65%) as a white solid: mp 83-84 ° C; UV (ethanol): λ _max 242 nm (ε 8500), 282 nm (ε 8800), λ _min 225 nm (ε 6400), 264 nm (ε 6300); ₁ H NMR (DMSO-d ₆ ): δ 7.8-7.3 (br d, 2H, NH ₂ ), 7.60 (d, 1H, H-6, J _6-F5 = 7.0 Hz) 5.93 (dd, 1H, H-1 ', J _1'-2' = 4.5 Hz and J _{1'-2 "} = 2.0 Hz), 5.2 (m, 1H, H-3 '), 4,1 (m, 1H , H-4'), 3,9-3,7 (m, 2H , H-5 'and ^H-5''), 3,17 (s, 3H, CH ₃ SO ₂ ), 2.7 (m, 1H, H-2 '), 2.1 (m, 1H, H- ^2`` ), 0.99 (s, 9H, (CH ₃ ) ₃ C-Si ), 0,05 (s, 6H, (CH _{z) 2} Si); MS (matrix GT): FAB> 0 m / z 875 (2M ⁺ H) +, 438 (M ⁺ H) +, 342 (M CH ₃ SO ₃ ) ⁺ , 130 (BH ₂ ) ⁺ ; FAB <0 m / z 873 (2M-H) ^- , 436 (M-H) ^- , 128 (B) ^- , 95 (CH ₃ SO ₃ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -28 (s, 0.96 DMSO).

1- (2,3-Dideoxy-3-azido-5-O-t-butyldimethylsilyl-β-L-erythro-pentofuranosyl) -5-fluorocytosine] 10

To a solution of compound 9 (520 mg, 1.19 mmol.) In anhydrous dimethylformamide (12 ml) was added lithium azide moistened with 10% methanol (300 mg, 5.31 mmol). The reaction mixture was stirred at 100 ° C for 2.5 hours, and then cooled to room temperature, poured into ice water (200 ml) and extracted with chloroform (3 × 100 ml). The combined extracts were washed with saturated aqueous sodium bicarbonate (2 × 100 ml), water (5 × 100 ml), and then dried over sodium sulfate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: methanol (4%) in chloroform] to obtain pure compound 10 (327 mg, 72%), crystallized from diethyl ether / methanol: mp. 146-147 ° C; UV (ethanol): _max 243 nm (ε 8700), 283 nm (ε 8400), λ _min 226 nm (ε 7200), 264 nm (ε 6700); ¹ H NMR (DMSO-d ₆ ): δ 7.90 (d, 1H, H-6, J _6-F5 = 7.0 Hz), 7.8-7.5 (br d, 2H, NH ₂ ) 6.0 (m, 1H, H-1 '), 4.3 (m, 1H, H-3'), 3.9-3.7 (m, 3H, H-4 ', H-5' and H '' - 5), 2.4-2.2 (m, 2H, H-2 'and H-2''), 0.87 (s, 9H, (CH ₃ ) ₃ C-Si), 0.05 (s, 6H, (CH ₃ ) ₂ Si); MS (GT matrix): FAB> 0 m / z 769 (2M + H) ⁺ , 385 (M + H) ⁺ , 130 (BH ₂ ) ⁺ , FAB <0 m / z 383 (M-H) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -67 (s, 0.96 DMSO).

1- (2,3-Dideoxy-3-azido-β-L-erythro-pentofuranosyl) -5-fluorocytosine 11, (3'-N ₃ -β-L-5-FddC)

A 1 M solution of tetrabutylammonium trifluoride in tetrahydrofuran (TBAF / THF, 1.53 ml, 1.53 mmol) was added to a solution of compound 10 (295 mg, 0.67 mmol) in anhydrous THF (4 ml). The resulting mixture was stirred at room temperature for 1.5 hours and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (4-8%) in chloroform]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and filtered through a Millex HV-4 apparatus (0.45 μm, Millipore) to give pure compound 11 (199 mg, 96%), crystallized from ethanol: mp. 188-189 ° C (letters: mp 164-166 ° C for the D-enantiomer); UV (ethanol): λ _max 243 nm (ε 8700), 283 nm (s 8100), λ _min 226 nm (ε 7100), 264 nm (ε 6500); ¹ H NMR (DMSO-d ₆ ): δ 8.08 (d, 1H, H-6, J _6-F5 = 7.3 Hz), 7.8-7.5 (br d, 2H, NH ₂ ) 6.0 (m, 1H, H1 '), 5.3 (br S, 1H, OH-5'), 4.4 (m, 1H, H-3 '), 3.8 (m, 1H, H-4 '), 3.7-3.5 (m, 2H, H-5' and H-5``), 2.3 (m, 2H, H-2 'and H-2''); MS (GT matrix): FAB> 0 m / z 811 (3M + H) ⁺ , 725 (2M + 2G + H) ⁺ , 633 (2M + G + H) ⁺ , 541 (2M + H) ⁺ , 363 ( M + G + H) ⁺ , 271 (M + H) ⁺ , 142 (S) ⁺ , 130 (BH ₂ ) ⁺ ; FAB <0 m / z 647 (2М + Т-Н) ^- , 539 (2М-Н) ^- , 377 (М + Т-Н) ^- , 269 (М-Н) ^- , 128 (В) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -31 (s, 0.90 DMSO); Anal (C ₉ H ₁₁ FN ₆ O ₃ ) C, H, N, F.

Analytical data are presented in table A.

Example 2

Preparation of β-L- (2'-azido) -2 ', 3'-dideoxy-5-fluorocytosine

The general procedures and instruments used are described in Example 1 in the experimental protocol part describing the synthesis of the 3'-isomer (3'-N ₃ -β-L-FddC).

1- (2-O-Acetyl-3-deoxy-5-O-benzoyl-β-L-erythro-pentofuranosyl) -5-fluorouracil 13

A suspension of 5-fluorouracil (5.15 g, 39.6 mmol) was treated with hexamethyldisilazane (HMDS, 257 ml) and a catalytic amount of ammonium sulfate for 18 hours under reflux. After cooling to room temperature, the mixture was evaporated under reduced pressure, and the residue, obtained as a colorless oil, was diluted with anhydrous 1,2-dichloroethane (290 ml). To the resulting solution was added 1,2-di-O-acetyl-3-deoxy-5-O-benzoyl-L-erythro-pentofuranose 12 (8.5 g, 26.4 mmol.) [See Mathe, C., Ph.D. Dissertation, Universite de Montpellier II -Sciences et Techniques du Languedoc, Montpellier (France), September 13, 1994; Gosselin, G .; Mathe, C .; Bergogne, M.-C .; Aubertin, AM; Kirn, A .; Sommadossi, JP; Schinazi, RF; Imbach, JL, "2'- and / or 3'-deoxy-β-L-pentofuranosyl nucleoside derivatives: stereospecific synthesis and antiviral activities," Nucleosides & Nucleotides. 1994, 14 (3-5), 611-617] in anhydrous 1,2-dichloroethane (120 ml), followed by the addition of trimethylsilyl trifluoromethanesulfonate (TMSTf, 9.6 ml, 52.8 mmol.). The solution was stirred for 5 hours at room temperature under argon, then diluted with chloroform (200 ml), washed with the same volume of a saturated aqueous solution of sodium bicarbonate, and finally with water (2 × 300 ml). The organic phase is dried over sodium sulfate and then evaporated under reduced pressure. The resulting crude material was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-6%) in methylene chloride] to give pure compound 13 (8.59 g, 83%), crystallized from toluene: mp 65-68 ° C; UV (ethanol): λ _max 228 nm (ε 11200), 268 nm (ε 14000), λ _min 242 nm (ε 7800); ¹ H NMR (DMSO-d ₆ ): δ 11.9 (br s, 1H, NH), 8.0-7.5 (m, 6H, C ₆ H ₅ CO and H-6), 5.8 ( m, 1H, H-1 '), 5.3 (m, 1H, H-2'), 4.6-4.5 (m, 3H, H-4 ', H-5' and H-5 ''), 2.4-2.3 (m, 1H, H-3'), 2.1-2.0 (m, 4H, H-3 '' and CH ₃ CO); MS (GT matrix): FAB> 0 m / z 393 (M + H) ⁺ , 263 (S) ⁺ , 105 (C ₆ H ₅ CO) ⁺ ; FAB <0 m / z 391 (MH) ^- , 331 (M- [CH ₃ CO ₂ H] -H) ^- , 129 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -8 (s, 1.00 DMSO); Anal (C ₁₈ H ₁₇ FN ₂ O _{7 ^2/3} C ₇ H ₈₎ C, H, N, F.

1- (3-Deoxy-5-O-benzoyl-β-L-erythro-pentofuranosyl) -5-fluorouracil 14

To a solution of compound 13 (5.90 g, 15.0 mmol) in tetrahydrofuran (THF, 175 ml) was added sodium methylate (2.84 g, 52.6 mmol.). The resulting suspension was stirred at room temperature for 5 hours and then neutralized by adding Dowex 50 WX 2 (H ⁺ form). The resin is filtered and washed with warm methanol, and the combined filtrates are evaporated to dryness. Column chromatography of the residue on silica gel [elution solvent: stepwise gradient of methanol (0-8%) in methylene chloride] yields compound 14 (4.11 g, 78%), crystallized from methylene chloride / methanol mixture: mp. 154-156 ° C; UV (ethanol): λ _max 226 nm (ε 23000), 268 nm (ε 16000), λ _min 246 nm (ε 8900); ¹ H NMR (DMSO-d ₆ ): δ 11.8 (br s, 1H, NH), 8.0-7.5 (m, 6H, C ₆ H ₅ CO and H-6), 5.6 ( br s, 2H, H-1 'and OH-2'), 4.5 (m, 3H, H-4 ', H-5' and H-5``), 4.3 (m, 1H, H -2 '), 2.1-2.0 (m, 1H, H-3'), 1.9 (m, 1H, H-3``); MS (GT matrix): FAB> 0 m / z 701 (2M + H) ⁺ , 351 (M + H) ⁺ , 221 (S) ⁺ , 131 (BH ₂ ) ⁺ , 105 (C ₆ H ₅ CO) ⁺ ; FAB <0 m / z 1049 (3M-H) ^- , 699 (2M-H) ^- , 441 (M + GH) ^- , 349 (M-H) ^- , 129 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -3 (C, 1.04 DMSO); Anal (C ₁₆ H ₁₅ FN ₂ O ₆ ) C, H, N, F.

1- (3-Deoxy-5-O-benzoyl-β-L-threo-pentofuranosyl) -5-fluorouracil 15

Dicyclohexicarbodiimide (DCC, 3.53 g, 17.1 mmol) and dichloroacetic acid (0.235 ml, 2.56 mmol) are added to a solution of compound 14 (2.00 g, 5.71 mmol.) In anhydrous benzene (50 ml) DMSO (35 ml) and pyridine (0.46 ml). The resulting solution was stirred at room temperature under argon for 4 hours and diluted with ethyl acetate (300 ml). Oxalic acid (1.54 g, 17.1 mmol.) Dissolved in methanol (4.6 ml) was added and the reaction mixture was stirred at room temperature for 1 h and then filtered to remove precipitated dicyclohexylurea (DCU). Before drying over sodium sulfate and evaporation under reduced pressure, the filtrate was washed with saturated brine (3 × 300 ml), saturated aqueous sodium bicarbonate (2 × 300 ml) and finally water (3 × 200 ml). The resulting residue was evaporated several times with absolute ethanol (31 ml) and anhydrous benzene (15 ml). The resulting solution was then cooled to 0 ° C and sodium borohydride (NaBH ₄ , 0.32 g, 8.56 mmol.) Was added to it. The reaction mixture was stirred at room temperature under argon for 1 h, diluted with ethyl acetate (300 ml) and filtered. Before drying over sodium sulfate and evaporation under reduced pressure, the filtrate is washed with a saturated aqueous solution of sodium chloride (3 × 300 ml) and water (2 × 200 ml). The resulting residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-6%) in chloroform] to obtain pure compound 15 (1.10 g, 55%) as a white foam: mp. 171-172 ° C; UV (ethanol): λ _max 228 nm (ε 14700) 270 nm (ε 9100), λ _min 248 nm (ε 5000); ¹ H NMR (DMSO-d ₆ ): δ 11.8 (br s, 1H, NH), 8.0-7.5 (m, 6H, C ₆ H ₅ CO and H-6), 5.90 ( dd, 1H, H-1 ', J _1'-2' = 4.1 Hz and J _1'-F5 = 1.8 Hz), 5.5 (br s, 1H, OH-2 '), 4, 7 (br q, 1H, H-4 ', J = 11.7 Hz and J = 7.0 Hz), 4.4-4.3 (m, 3H, H-2', H-5 'and H -5 "), 2.4 (m, 1H, H-3 '), 1.9-1.8 (m, 1H, H-3''); MS (GT matrix): FAB> 0 m / z 701 (2M + H) ⁺ , 351 (M + H) ⁺ , 221 (S) ⁺ , 131 (BH ₂ ) ⁺ , 105 (C ₆ H ₅ CO) ⁺ ; FAB <0 m / z 1049 (3M-H ) ^- , 699 (2M-H) ^- , 349 (M-H) ^- , 129 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -101 (s, 0.70 DMSO)

1- (2-O-Acetyl-3-deoxy-5-O-benzoyl-β-L-threo-pentofuranosyl) 5-fluorouracil 16

Acetic anhydride (0.88 ml, 9.28 mmol) was added under argon to a solution of compound 15 (2.50 g, 7.14 mmol) in dry pyridine (50 ml) and the resulting mixture was stirred at room temperature for 22 hours. Then ethanol was added and the solvents were evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-2%) in methylene chloride) to obtain pure compound 16 (2.69 g, 96%) as a white foam; mp = 68-70 ° C (foam); UV (ethanol): λ _max = 239 nm (ε = 15000) 267 nm (ε = 8800), λ _min = 248 nm (ε = 5600); ¹ H NMR (DMSO-d ₆ ): δ ppm 11.9 (br s, 1H, NH), 8.1-7.5 (m, 6H, C ₆ H ₅ CO and H-6), 6.10 (d, 1H, H-1 ', J _1'-2' = 4.3 Hz), 5.4 (m, 1H, H-2 '), 4.6-4.4 (m, 3H, H -4 ', H-5' and H-5 ''), 2.6 (m, 1H, H-3 '), 2.03 (m, 1H, H-3 "), 1.86 (s, 3H, CH ₃ CO); MS (GT matrix): FAB> 0 m / z 785 (2M + H) ⁺ , 393 (M + H) ⁺ , 263 (S) ⁺ , 131 (BH ₂ ) ⁺ , 105 ( C ₆ H ₅ CO) ⁺ , 43 (CH ₃ CO) ⁺ , FAB <0 m / z 391 (M-H) ^- , 129 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- , 59 (CH ₃ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -81 (s, 0.95 DMSO).

1- (2-O-Acetyl-3-deoxy-5-O-benzoyl-β-L-threo-pentofuranosyl) -4-thio-5-fluorouracil 17

Lawesson's reagent (1.9 g, 4.69 mmol) was added under argon to a solution of compound 16 (2.63 g, 6.70 mmol) in anhydrous 1,2-dichloroethane (165 ml) and the reaction mixture was stirred overnight under reflux. Then, the solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (0-3%) in methylene chloride] to obtain 4-derivative 17 (2.65 g, 96% yield) as yellow foam; mp = 78-79 ° C (foam); UV (ethanol): λ _max = 230 nm (ε = 15900) 334 nm (ε = 15600), λ _min = 288 nm (ε = 3200); ¹ H NMR (DMSO-d ₆ ): δ ppm 13.2 (br s, 1H, NH), 8.1-7.5 (m, 6H, C ₆ H ₅ CO and H-6), 6.08 (d , 1H, H-1 ', J _1'-2' = 4.3 Hz), 5.4 (m, 1H, H-2 '), 4.7-4.4 (m, 3H, H-4', H- 5 'and H-5''), 2.6 (m, 1H, H-3'), 2.0 (m, 1H, H-3 ''), 1.84 (s, 3H, CH ₃ CO); MS (GT matrix): FAB> 0 m / z 409 (M + H) ⁺ , 263 (S) ⁺ , 147 (BH ₂ ) ⁺ , 105 (C ₆ H ₅ CO) ⁺ , 43 (CH ₃ CO) ⁺ ; FAB <0 m / z 407 (M-H) ^- , 145 (B) ^- , 121 (C ₆ H ₅ CO ₂ ) ^- , 59 (CH ₃ CO ₂ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -155 (s, 1, 00 DMSO).

1- (3-Deoxy-β-L-threo-pentofuranosyl) -5-fluorocytosine 18

H₂O; Вычислено: 42,52; Н=5,15; N=16,53; F=7,47; Найдено С=43,16; H=5,32; N=16,97; F=6,92A solution of 4-derivative 17 (0.86 g, 2.19 mmol.) In methanol ammonia (pre-saturated at -10 ° C and tightly corked) (44 ml) is heated at 100 ° C in a stainless steel container for 3 hours and then cooled to 0 ° C. The solution was evaporated to dryness under reduced pressure, and the residue was evaporated several times with methanol. The crude material is dissolved in water and the resulting solution is washed four times with methylene chloride. The aqueous layer was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (3-12%) in chloroform]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and filtered through a Millex HV-4 apparatus (0.45 μm, Millipore) to obtain 0.46 g of compound 18 (86% yield), crystallized from methylene / methanol; mp = 137-138 ° C; UV (ethanol): λ _max = 240 nm (ε = 8300), 284 nm (ε = 8100), λ _min = 226 nm (ε = 7300), 263 nm (ε = 5500); ¹ H NMR (DMSO-d ₆ ): δ ppm 8.34 (d, 1H, H-6, J _6-F5 = 7.5 Hz), 7.7-7.4 (br pd, 2H, NH ₂ ), 5.83 (dd, 1H, H-1 ', J _1'-2' = 4.4 Hz, J _1'-F5 = 1.9 Hz), 5.22 (d, 1H, OH-2 ', J _OH-2' = 5.1 Hz), 5.15 (t, 1H, OH-5 ', J _OH-5' = J _{OH-5 "} = 4.8 Hz), 4.3 (m , 1H, H-2 '), 4.0 (m, 1H, H-4'), 3.6-3.5 (m, 2H, H-5 'and H-5``), 2.2 (m, 1H, H-3 '), 1.7 (m, 1H, H-3``); MS (GT matrix): FAB> 0 m / z 491 (2M + H) ⁺ , 246 (M + H) ⁺ , 130 (BH ₂ ) ⁺ ; FAB <0 m / z 244 (M-H) ^- , 128 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -135 (s, 0.89 DMSO). Elemental analysis of C ₉ H ₁₂ FN ₃ O ₄ ,

H ₂ O; Calculated: 42.52; H = 5.15; N = 16.53; F = 7.47; Found C = 43.16; H = 5.32; N = 16.97; F = 6.92

1- (3-Deoxy-5-O-t-butyldimethylsilyl-β-L-threo-pentofuranosyl) -5-fluorocytosine 19

To a solution of compound 18 (1.38 g, 5.63 mmol) in dry pyridine (30 ml), t-butyldimethylsilyl chloride (1.10 g, 7.32 mmol) was added dropwise under an argon atmosphere, and the mixture was stirred for 10 hours at room temperature. The mixture was then poured into saturated aqueous sodium bicarbonate (100 ml) and extracted with chloroform (3 × 150 ml). The combined extracts were washed with water (2 × 200 ml) and then dried over sodium sulfate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (2-10%) in methylene chloride] to obtain pure compound 19 (1.74 g, 86% yield) as a white solid: mp. 202-204 ° C; UV (ethanol): λ _max 241 nm (ε 7800), 284 nm (ε 7800), λ _min 226 nm (ε 6600), 263 nm (ε 5400); ¹ H NMR (DMSO-d ₆ ): δ 7.77 (d, 1H, H-6, J _6-F5 = 7.1 Hz), 7.7-7.3 (br d, 2H, NH ₂ ) 6.88 (dd, 1H, H-1 ', J _1'-2' = 4.9 Hz and J _1'-F5 = 1.9 Hz), 5.24 (d, 1H, OH-3 ' , J _{OH-3 '} = 4.6 Hz), 4.4 (m, 1H, H-2'), 4.0 (m, 1H, H-4 '), 3.8-3.7 (m , 2H, H-5 'and H-5''), 2.2 (m, 1H, H-3'), 1.7 (m, 1H, H-3 "), 0.84 (s, 9H , (CH ₃ ) ₃ C-Si), 0.06 (s, 6H, (CH ₃ ) ₂ Si); MS (GT matrix): FAB> 0 m / z 1437 (4M + H) ⁺ , 1078 (3M + H) ⁺ , 719 (2M + H) ⁺ , 360 (M + H) ⁺ , 231 (S) ⁺ , 130 (BH ₂ ) ⁺ , 115 (TBDMS) ⁺ ; FAB <0 m / z 1076 (3M- H) ^- , 717 (2M-H) ^- , 358 (M-H) ^- , 128 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -107 (s, 0.88 DMSO).

1- (3-Deoxy-2-O-mesyl-5-O-t-butyl-dimethylsilyl-β-L-threo-pentofuranosyl) -5-fluorocytosine 20

A suspension of compound 19 (1.70 g, 4.73 mmol.) In dry pyridine (80 ml) was stirred under argon atmosphere and cooled to 0 ° C. Methanesulfonyl chloride (MsCl, 1.21 ml, 15.6 mmol) was added dropwise and the reaction mixture was stirred at 0 ° C for 5 hours. Then, the mixture was poured into ice water (300 ml) and extracted with chloroform (3 × 300 ml) . The combined extracts were washed with 5% aqueous sodium bicarbonate (300 ml), water (2 × 300 ml), and then dried over sodium sulfate and evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (8-12%) in toluene] to give pure compound 20 (1.41 g, 68% yield) as a white solid: mp 75-76 ° C; UV (ethanol): λ _max 243 nm (ε 8100), 282 nm (ε 7300), λ _min 225 nm (ε 6000), 265 nm (ε 6000); ¹ H NMR (DMSO-d ₆ ): δ 7.9-7.6 (br d, 2H, NH ₂ ), 7.85 (d, 1H, H-6, J _6-F5 = 7.0 Hz) 6.08 (dd, 1H, H-1 ', J _1'-2' = 5.2 Hz and J _1'-F5 = 1.6 Hz), 5.4 (m, 1H, H-2 ' ), 4.1 (m, 1H, H-4 '), 3.9 (m, 1H, H-5'), 3.7 (m, 1H, H-5``), 3.11 (s , 3H, CH ₃ SO ₂ ), 2.47 (m, 1H, H-3 '), 2.0 (m, 1 H, H-2''), 0.85 (s, 9H, (CH ₃ ) ₃ C-Si), 0.05 (s, 6H, (CH ₃ ) ₂ Si); MS (GT matrix): FAB> 0 m / z 1312 (3M + H) ⁺ , 875 (2M + H) ⁺ , 438 (M + H) ⁺ , 309 (S) ⁺ , 130 (BH ₂ ) ⁺ ; FAB <0 m / z 1310 (2M-H) ^- , 873 (2M-H) ^- , 436 (M-H) ^- , 128 (B) ^- , 95 (CH ₃ SO ₃ ) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = -84 (s, 0.84 DMSO).

1- (2,3-Dideoxy-2-azido-5-O-t-butyldimethylsilyl-β-L-erythro-pentofuranosyl) -5-fluorocytosine 21

To a solution of compound 20 (442 mg, 1.01 mmol) in anhydrous dimethylformamide (12 ml) was added lithium azide moistened with 10% methanol (265 mg, 4.87 mmol). The reaction mixture was stirred at 100 ° C for 2.5 hours, and then cooled to room temperature, poured into ice water (200 ml) and extracted with chloroform (3 × 100 ml). The combined extracts were washed with saturated aqueous sodium bicarbonate (2 × 100 ml), water (5 × 100 ml), and then dried over sodium sulfate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: methanol (4%) in chloroform] to obtain pure compound 21 (291 mg, 75% yield) as a white solid: mp. 147-148 ° C; UV (ethanol): λ _max 242 nm (ε 7700), 283 nm (ε 7400), λ _min 226 nm (ε 6600), 264 nm (ε 5800); ¹ H NMR (DMSO-d ₆ ): δ 8.05 (d, 1H, H-6, J _6-F5 = 7.0 Hz), 7.9-7.4 (br d, 2H, NH ₂ ) 5.7 (br s, 1H, H-1 '), 4.37 (d, 1H, H-2', J _{2'-3 '} = 5.5 Hz), 4.3 (m, 1H, H-4 '), 4 (m, 1H, H-5'), 3.7 (m, 1H, H-5 ''), 2.0 (m, 1H, H-3 '), 1.8 (m, 1H, H-3``), 0.88 (s, 9H, (CH ₃ ) ₃ C-Si), 0.05 (s, 6H, (CH ₃ ) ₂ Si); MS (GT matrix): FAB> 0 m / z 769 (2M + H) ⁺ , 385 (M + H) ⁺ , 130 (BH ₂ ) ⁺ ; FAB <0 m / z 1151 (3M-H) ^- , 767 (2M-H) ^- , 383 (M-H) ^- , 128 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = + 25 (s, 0.95 DMSO).

1- (2,3-Dideoxy-2-azido-β-L-erythro-pentofurazonyl) -5-fluorocytosine 22 (2'-N ₃ -β-L-5-FddC)

A 1M solution of tetrabutylammonium trifluoride in tetrahydrofuran (TBAF / THF, 1.90 ml, 1.90 mmol) was added to a solution of compound 21 (480 mg, 1.25 mmol) in anhydrous THF (8 ml). The resulting mixture was stirred at room temperature for 1.5 hours and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [elution solvent: stepwise gradient of methanol (4-8%) in chloroform]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and filtered through a Millex HV-4 apparatus (0.45 μm, Millipore) to give pure compound 22 (304 mg, 90% yield), crystallized from ethanol: mp. 219-221 ° C; UV (ethanol): λ _max 241 nm (ε 7700), 284 nm (ε 7300), λ _min 225 nm (ε 6500), 263 nm (ε 5400); ¹ H NMR (DMSO-d ₆ ): δ 8.31 (d, 1H, H-6, J _6-F5 = 7.4 Hz), 7.9-7.4 (br d, 2H, NH ₂ ) 5.65 (m, 1H, H-1 '), 5.32 (br s, 1H, OH-5'), 4.35 (d, 1H, H-2 ', J _2'-3' = 5.6 Hz), 4.2 (m, 1H, H-4 '), 3.8 (m, 1H, H-5'), 3.6 (m, 1H, H-5``), 2 , 1 (m, 1H, H-3 '); 1.8 (m, 1H, H-2''); MS (GT matrix): FAB> 0 m / z 541 (2M + H) ⁺ , 363 (M + G + H) ⁺ , 271 (M + H) ⁺ , 130 (BH ₂ ) ⁺ , FAB <0 m / z 539 (2M-H) ^- , 269 (M-H) ^- , 128 (B) ^- ; [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = + 29 (s, 0.85 DMSO); Anal (C ₉ H ₁₁ FN ₆ O ₃ ) C, H, N, F.

Analytical data are presented in table B.

Anti-HBV activity

The ability of β-L- (2 ′ or 3′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine compounds to inhibit HBV replication in the host can be determined by any known method, including the method described below.

Antiviral evaluation is carried out on two separate cell passages, two cultures per passage (a total of 4 cultures). All cells on all tablets are seeded at the same density and at the same time.

Due to the inherent fluctuations in the levels of both intracellular and extracellular HBV DNA, only the suppression is more than 3.0 times (for HBV virion DNA) or 2.5 times (for HBV DNA replication intermediates), which differs from the average level for of such forms of HBV DNA in untreated cells are generally considered statistically significant [P <0.05] (Korba and Gerin, Antiviral Res. 19: 55-70, 1992). The level of integrated HBV DNA in each cell DNA preparation (remaining constant in such experiments per cell) is used to determine the level of intracellular forms of HBV DNA, thereby eliminating the technical variations inherent in blot hybridization assays.

Typical levels of extracellular HBV virion DNA in untreated cells range from 50 to 150 pg / ml culture medium (average level is approximately 76 pg / ml). The level of HBV intracellular DNA replication intermediates in untreated cells ranges from 50 to 100 pg / μg of DNA cells (the average is approximately 74 pg / μg of DNA cells). In general, a decrease in the level of intracellular HBV DNA due to treatment with antiviral compounds is less pronounced and slower than a suppression of the level of HBV virion DNA.

For comparison, the results of hybridization assays obtained in these experiments correspond to approximately 1.0 pcg of intracellular HBV DNA / μg of cellular DNA to 2-3 genomic copies per cell, and 1.0 pcg of extracellular HBV DNA / ml of culture medium to 3 · 10 ⁵ viral particles / ml.

Toxicity tests are performed to determine if any observed antiviral effect occurs due to the overall effect on cell viability. This can be established by absorption of a neutral red dye, i.e. a standard and widely used cell viability test in a variety of host virus systems, including HSV (herpes virus) and HIV.

Test compounds are used in the form of stock solutions of DMSO (frozen on dry ice). Prepare daily aliquots of test samples and freeze them at -20 ° C so that each individual aliquot is subjected to only one freeze-thaw cycle. Daily test aliquots of the part are thawed, suspended in the culture medium at room temperature and immediately added to the cell cultures. The results are presented in table 1.

Example 3

Toxicity of compounds

The ability of the active compounds to inhibit the growth of the virus in cell cultures 2.2.15 (Hep G2 cells transformed by hepatitis virion) is determined. As follows from table 1, at a concentration of 100 μm, there is no significant toxicity (exceeding 50% inhibition of the level of dye absorption observed in untreated cells) of all tested compounds.

Toxicity analyzes were performed in 96-well flat-bottom plates for tissue cultures. Cells for toxicity analysis are cultured and treated with test compounds in the same manner as in the determination of antiviral activity. Each compound was tested in four concentrations and in three cultures. To determine the relative level of toxicity, neutral red dye absorption is used. Quantitative analysis is carried out by absorption at 510 nm (A ₅₁₀ ) of the internalized dye. The results are presented as percentages of mean values of A ₅₁₀ (± standard deviation) of 9 different cultures of untreated cells found in the same 96-well plate as test compounds. The percentage of dye uptake in 9 control cultures on plate 40 is 100 ± 3. At 150-190 μm β-D-ddC, such analyzes typically show a 2-fold decrease in dye uptake (relative to the level observed in untreated cultures) (Korba and Gerin, Antiviral Res. 19: 55-70, 1992).

Example 4

The effect of anti-HBV β-L-deoxycytidine analogues on cell growth as determined by clonogenic analyzes of human bone marrow

The effect of anti-HBV β-L-deoxycytidine analogues on cell growth as determined by clonogenic analyzes of human bone marrow is shown in Table 2.

Obtaining pharmaceutical compositions

The compounds described herein and their pharmaceutically acceptable salts, prodrugs and derivatives can be used to prevent and treat HBV infections and the like, such as anti-HBV antibody positive and HBV positive conditions, HBV-induced chronic liver inflammation, cirrhosis, acute hepatitis, fulminant hepatitis, chronic persistent hepatitis and fatigue. Such compounds or compositions can also be used prophylactically to prevent or slow down a clinical disease in anti-HBV antibody or HBV antigen-positive patients or in contact with HBV.

Patients suffering from any of the above conditions may be treated by administering an effective amount of one of the active compounds described herein or a mixture thereof, or a pharmaceutically acceptable derivative or salt thereof, optionally together with a pharmaceutically acceptable carrier or diluent, to treat HBV. The active materials may be administered by any suitable means, for example, oral, parenteral, intravenous, intradermal, subcutaneous or local, in liquid or solid form.

The active compound is included in a pharmaceutically acceptable carrier or diluent in an amount sufficient to provide the patient with a therapeutically active amount without causing a serious toxic effect.

The preferred dose of the active compound for all of the above conditions is from about 1 to 60 mg / kg, preferably from 1 to 20 mg / kg of body weight per day, more broadly, from 0.1 to about 100 mg per kilogram of recipient body weight per day. An effective dose range of pharmaceutically acceptable derivatives can be calculated based on the weight of the parent parent nucleoside administered. If the derivative has independent activity, then the effective dosage can be calculated, as indicated above, on the basis of the mass of the derivative or by other methods known to specialists in this field. In accordance with one embodiment of the present invention, the active compound is administered as indicated in the instructions attached to the product or in the Physician's Desk Reference for 3'-azido-3'-deoxythymidine (AZT), 2 ', 3'-dideoxyinosine (DDI), 2 ', 3'-dideoxycytidine (DDC) or 2', 3'-dideoxy-2 ', 3'-didehydrothymidine (D4T) for administration in HIV.

It is advisable to administer the compound in the form of any dosage form, including, but not limited to, a form containing from 7 to 3000 mg, preferably from 70 to 1400 mg, of the active ingredient per unit dose. An oral dose containing 50-1000 mg is usually suitable.

Ideally, the active ingredient to be administered should provide the highest concentration of the active compound in plasma of about 0.2 to 70 mM, preferably about 1.0 to 10 mM. This can be achieved, for example, by intravenous injection of a 0.1-5% solution of the active ingredient, optionally in saline, or administered as a bolus of the active ingredient.

The active compound may be prepared as pharmaceutically acceptable salts. As used herein, the term “pharmaceutically acceptable salts or complexes” refers to salts or nucleoside complexes that retain the necessary biological activity of the parent compound and do not have or have minimal toxicological effect.

Non-limiting examples of such salts include (a) acid addition salts formed with inorganic acids (e.g. hydrochloric, hydrobromic, sulfuric, phosphoric, nitric acid, etc.), as well as salts formed with organic acids, such as acetic oxalic, tartaric, succinic, malic, ascorbic, benzoic, tannic, pamic, alginic, polyglutamic, naphthalenesulfonic, naphthalene disulfonic acids and polygalacturonic acid; (b) base addition salts formed with cations such as sodium, potassium, zinc, calcium, bismuth, barium, magnesium, aluminum, copper, cobalt, nickel, cadmium and the like, or with an organic cation derived from N , N-dibenzylethylenediamine, ammonium or ethylenediamine; or (c) a combination of (a) and (b); e.g. zinc tannate salt or the like

Modifications of the active compound specifically at positions N ⁶ or N ⁴ and 5'-O can provide bioavailability and the necessary level of metabolism of active substances, thus providing control over their delivery.

The concentration of the active compound in the composition of the drug depends on the level of absorption, inactivation and excretion, as well as on other factors known to specialists in this field. It should be noted that the dose value also varies depending on the severity of the condition being treated. It should also be noted that for each individual patient, over time, it is necessary to select specific intake regimens in accordance with the individual need and professional opinion of the person administering or controlling the administration of the formulations, and that the concentration ranges indicated here are only illustrative and are not intended to limit the volume or application the claimed composition. The active ingredient may be administered at one time or may be divided into several smaller doses administered at different time intervals.

The preferred route of administration of the active compound is oral. Compositions for oral administration usually include an inert diluent or food carrier. They can be enclosed in gelatin capsules or compressed into tablets. For oral therapeutic administration, the active compound can be mixed with excipients and used in the form of tablets, troches, or capsules. Pharmaceutically compatible binders and / or adjuvants may also form part of the composition.

Tablets, pills, capsules, lozenges, etc. may contain any of the following ingredients or compounds of a similar nature: a binder, such as microcrystalline cellulose, tragacanth or gelatin; a formative substance, such as starch or lactose, a disintegrant, such as alginic acid, Primogel or corn starch; a lubricant such as magnesium stearate or Sterotes; glidant (a glidant), such as colloidal silicon dioxide; a sweetener such as sucrose or saccharin; or a fragrance such as mint, methyl salicylate or orange. If the dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a fatty oil. In addition, the dosage form may contain various other materials that modify its physical form, for example, a coating of sugar, shellac or other enteric agents.

The active compound or a pharmaceutically acceptable salt or derivative thereof may be administered as a component of an elixir, suspension, syrup, water, chewing gum or the like. In addition to the active compounds, the syrup may contain sucrose as a sweetener and some preservatives, dyes, pigments and perfumes.

The active compound or its pharmaceutically acceptable derivative or salt can also be mixed with other active materials that do not impair the desired effect, or with materials that complement the desired effect, such as antibiotics, antifungal, anti-inflammatory or other antiviral drugs, including anti-HBV, anti cytomegalovirus or anti-HIV agents.

Solutions or suspensions used for parenteral, intradermal, subcutaneous or topical administration may include the following components: a sterile diluent, such as water for injection, saline, fatty oils, polyethylene glycols, glycerin, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates, and tone control agents such as sodium chloride or dextrose. The parenteral preparation can be enclosed in ampoules, single-dose syringes or multi-dose vials made of glass or plastic.

For intravenous administration, preferred carriers are physiological saline or phosphate buffered saline (PBS). In accordance with a preferred embodiment of the present invention, the active compounds are prepared together with carriers that protect the compound from rapid excretion from the body, for example, in the form of a controlled release composition, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters and polylactic acid can be used. Methods for preparing such formulations are apparent to those skilled in the art. Materials may also be purchased from Alza Corporation and Nova Pharmaceuticals, Inc.

Liposomal suspensions (including liposomes targeting infected cells with monoclonal antibodies to viral antigens) are also preferred as pharmaceutically acceptable carriers. They can be obtained in accordance with methods known to specialists in this field, for example, described in US patent No. 4,522,811. For example, compositions of liposomes can be obtained by dissolving the corresponding lipid (s) (such as stearoylphosphatidylethanolamine, stearoylphosphatidylcholine, peanut-doylphosphatidylcholine and cholesterol) in an inorganic solvent, which is then evaporated, obtaining a thin film of dry lipid on the surface of the container. Then, an aqueous solution of the active compound or its monophosphate, diphosphate and / or triphosphate derivative is placed in the container. The container is then shaken manually to separate the lipid material from the walls of the container and disperse the lipid aggregates, thereby obtaining a liposomal suspension.

The present invention has been described with reference to preferred embodiments thereof. Variations and modifications of the invention are apparent to those skilled in the art from the foregoing detailed description of the invention. It is implied that all these variations and modifications are included in the scope of the attached claims.

Claims (100)

1. A method for treating hepatitis B virus infection in the body, comprising administering an effective amount of a compound β-L- (2′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrug thereof formulas

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl. 2. The method according to claim 1, in which R represents N. 3. The method according to claim 1, in which R is acyl. 4. The method according to claim 1, in which R represents monophosphate. 5. The method according to claim 1, in which R represents diphosphate. 6. The method according to claim 1, in which R represents a triphosphate. 7. The method according to claim 1, in which R represents a stabilized phosphate derivative. 8. A method of treating hepatitis B virus infection in the body, comprising administering an effective amount of a compound β-L- (3′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrug thereof formulas

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl. 9. The method of claim 8, in which R represents N. 10. The method of claim 8, in which R is acyl. 11. The method of claim 8, in which R represents monophosphate. 12. The method of claim 8, in which R represents diphosphate. 13. The method of claim 8, in which R represents a triphosphate. 14. The method of claim 8, in which R represents a stabilized phosphate derivative. 15. β-L- (2′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester thereof, its salts or prodrugs of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl. 16. The compound according to clause 15, in which R represents N. 17. The compound of claim 15, wherein R is acyl. 18. The compound of claim 15, wherein R is monophosphate. 19. The compound of claim 15, wherein R is diphosphate. 20. The compound of claim 15, wherein R is triphosphate. 21. The compound of claim 15, wherein R is a stabilized phosphate derivative. 22. β-L- (3′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester thereof, its salts or prodrugs of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl. 23. The compound according to item 22, in which R represents N. 24. The compound of claim 22, wherein R is acyl. 25. The compound of claim 22, wherein R is monophosphate. 26. The compound of claim 22, wherein R is diphosphate. 27. The compound of claim 22, wherein R is triphosphate. 28. The compound of claim 22, wherein R is a stabilized phosphate derivative. 29. A pharmaceutical composition for treating hepatitis B virus infection in the body, comprising an effective amount of a compound β-L- (2′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrugs of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl, in combination with a pharmaceutically acceptable carrier. 30. The composition according to clause 29, in which R represents N. 31. The composition according to clause 29, in which R represents acyl. 32. The composition according to clause 29, in which R represents monophosphate. 33. The composition according to clause 29, in which R represents diphosphate. 34. The composition according to clause 29, in which R represents a triphosphate. 35. The composition according to clause 29, in which R represents a stabilized phosphate derivative. 36. A pharmaceutical composition for treating hepatitis B virus infection in the body, comprising an effective amount of a compound β-L- (3′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrugs of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl, in combination with a pharmaceutically acceptable carrier. 37. The composition according to clause 36, in which R represents N. 38. The composition according to clause 36, in which R represents acyl. 39. The composition of claim 36, wherein R is monophosphate. 40. The composition according to clause 36, in which R represents diphosphate. 41. The composition according to clause 36, in which R represents a triphosphate. 42. The composition according to clause 36, in which R represents a stabilized phosphate derivative. 43. β-L- (2′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine, a pharmaceutically acceptable ester, salt or prodrug thereof, of the formula:

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl, as an active principle for the treatment of hepatitis B virus infection in humans or other animals. 44. β-L- (3′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl, as an active principle for the treatment of hepatitis B virus infection in humans or other animals. 45. β-L- (2′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl, as the active ingredient of a preparation for treating hepatitis B virus infection in a human or other animal. 46. β-L- (3′-azido) -2 ′, 3′-dideoxy-5-fluorocytosine or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula

where R represents H, acyl, monophosphate, diphosphate or triphosphate or a stabilized phosphate derivative; R 'represents H, acyl or alkyl, as the active ingredient of a drug for treating hepatitis B virus infection in a human or other animal. 47. The method according to claim 1 or 8, in which R and R 'represent N. 48. The method according to claim 1 or 8, in which R represents acyl, and R 'represents N. 49. The method according to claim 1 or 8, in which R represents monophosphate, and R 'represents N. 50. The method according to claim 1 or 8, in which R represents diphosphate, and R 'represents N. 51. The method according to claim 1 or 8, in which R represents a triphosphate, and R 'represents N. 52. The method according to claim 1 or 8, in which R represents a stabilized phosphate derivative, and R ’represents N. 53. The method according to claim 1 or 8, in which R is H and R 'is alkyl. 54. The method according to claim 1 or 8, in which R is acyl, and R 'is alkyl. 55. The method according to claim 1 or 8, in which R is monophosphate, and R 'is alkyl. 56. The method according to claim 1 or 8, in which R represents diphosphate, and R 'represents alkyl. 57. The method according to claim 1 or 8, in which R represents a triphosphate, and R 'represents alkyl. 58. The method according to claim 1 or 8, in which R represents a stabilized phosphate derivative, and R 'represents alkyl. 59. The method according to claim 1 or 8, in which R represents H, and R 'represents acyl. 60. The method according to claim 1 or 8, in which R and R 'represent acyl. 61. The method according to claim 1 or 8, in which R represents monophosphate, and R 'represents acyl. 62. The method according to claim 1 or 8, in which R represents diphosphate, and R 'represents acyl. 63. The method according to claim 1 or 8, in which R represents a triphosphate, and R 'represents acyl. 64. The method according to claim 1 or 8, in which R represents a stabilized phosphate derivative, and R 'represents acyl. 65. The compound of claim 15 or 22, wherein R and R 'are N. 66. The compound of claim 15 or 22, wherein R is acyl and R 'is H. 67. The compound of claim 15 or 22, wherein R is monophosphate and R 'is H. 68. The compound of claim 15 or 22, wherein R is diphosphate and R 'is N. 69. The compound of claim 15 or 22, wherein R is triphosphate and R 'is N. 70. The compound of claim 15 or 22, wherein R is a stabilized phosphate derivative and R ′ is H. 71. The compound of claim 15 or 22, wherein R is H and R 'is alkyl. 72. The compound of claim 15 or 22, wherein R is acyl and R 'is alkyl. 73. The compound of claim 15 or 22, wherein R is monophosphate and R 'is alkyl. 74. The compound of claim 15 or 22, wherein R is diphosphate and R 'is alkyl. 75. The compound of claim 15 or 22, wherein R is triphosphate and R 'is alkyl. 76. The compound of claim 15 or 22, wherein R is a stabilized phosphate derivative and R ′ is alkyl. 77. The compound of claim 15 or 22, wherein R is H and R 'is acyl. 78. The compound of claim 15 or 22, wherein R and R 'are acyl. 79. The compound of claim 15 or 22, wherein R is monophosphate and R 'is acyl. 80. The compound of claim 15 or 22, wherein R is diphosphate and R 'is acyl. 81. The compound of claim 15 or 22, wherein R is triphosphate and R 'is acyl. 82. The compound of claim 15 or 22, wherein R is a stabilized phosphate derivative and R 'is acyl. 83. The composition according to clause 29 or 36, in which R and R 'represent N. 84. The composition according to clause 29 or 36, in which R represents acyl, and R 'represents N. 85. The composition according to clause 29 or 36, in which R represents monophosphate, and R 'represents N. 86. The composition according to clause 29 or 36, in which R represents diphosphate, and R 'represents N. 87. The composition according to clause 29 or 36, in which R represents a triphosphate, and R 'represents N. 88. The composition according to clause 29 or 36, in which R represents a stabilized phosphate derivative, and R 'represents N. 89. The composition according to clause 29 or 36, in which R is H and R 'is alkyl. 90. The composition according to clause 29 or 36, in which R is acyl and R 'is alkyl. 91. The composition according to clause 29 or 36, in which R is monophosphate and R 'is alkyl. 92. The composition according to clause 29 or 36, in which R is diphosphate and R 'is alkyl. 93. The composition of claim 29 or 36, wherein R is triphosphate and R ′ is alkyl. 94. The composition of claim 29 or 36, wherein R is a stabilized phosphate derivative and R ′ is alkyl. 95. The composition according to clause 29 or 36, in which R represents H, a R 'represents acyl. 96. The composition according to clause 29 or 36, in which R and R 'represent acyl. 97. The composition according to clause 29 or 36, in which R represents monophosphate, and R 'represents acyl. 98. The composition according to clause 29 or 36, in which R represents diphosphate, and R 'represents acyl. 99. The composition according to clause 29 or 36, in which R represents a triphosphate, and R 'represents acyl. 100. The composition according to clause 29 or 36, in which R represents a stabilized phosphate derivative, and R 'represents acyl.

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