AU2003261475B2 - Beta-L-2'-deoxy-nucleosides for the treatment of HIV infection - Google Patents

Description

8-11-03;15;44 ;Blake Dawson Waldron ;613 98783111 6/ 57

AUSTRALIA

Patents Act 1990 Centre National De La Recherche Scientifique and The UAB Research Foundation and Emory University COMPLETE SPECIFICATION STANDARD PATENT Invention Title: P-L-2'-deoxy-nucleosides for the treatment of HIV infection The following statement is a full description of this invention, including the best method of performing it known to us; 141578797 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 7/ 57 L-2'-Deoxy-Nucleosides for the Treatment of HIV Infection Background of the Invention This invention is in the area of methods for the treatment of human immunodeficiency virus (also referred to as "HIV") that includes administering to a host in need thereof either alone or in combination, an effective HIV-treatment amount of one or more of the active compounds disclosed herein, or a pharmaceutically acceptable prodrug or salt of one of these compounds.

In 1981, acquired immune deficiency syndrome (AIDS) was identified as a disease that severely compromises the human immune system, and that almost without exception leads to death. In 1983, the etiological cause of AIDS was determined to be the human immunodeficiency virus (HIV).

In 1985, it was reported that the synthetic nucleoside 3'-azido-3'-deoxythymidine (AZT) inhibits the replication of human immunodeficiency virus. Since then, a number of other synthetic nucleosides, including (-)-p-2',3'-dideoxy-3'-thiacytidine (3TC), (FTC), 2',3'-dideoxyinosine (DDI), 2',3'-dideoxycytidine (DDC), and 2',3'-dideoxy-2',3'-didehydrothymidine (D4T), have been proven to be effective against HIV. After cellular phosphorylation to the 5'-triphosphate by cellular kinases, these synthetic nucleosides are incorporated into a growing strand of viral DNA, causing chain termination due to the absence of the 3'-hydroxyl group. They can also inhibit the viral enzyme reverse transcriptase.

The success of various synthetic nucleosides in inhibiting the replication of HIV in vivo or in vitro has led a number of researchers to design and test nucleosides that substitute a heteroatom for the carbon atom at the 3'-position of the nucleoside. European Patent Application Publication No. 0 337 713 and U.S. Patent No. 5,041,449, assigned to BioChem Pharma, Inc., disclose racemic 2-substituted-4-substituted-l,3-dioxolanes that exhibit antiviral activity. U.S. Patent No. 5,047,407 and European Patent Application Publication No. 0 382 526, also assigned to BioChem Pharma, Inc., disclose that a number of racernic 2substituted-5-substitutd-,3-oxathiolane nucleosides have antiviral activity, and specifically report that the raceric mixture of 2-hydroxymethyl-5-(cytosin- -yl)-l,3-oxathiolane 1 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron 136611#8/5 F613 96763111 8/ 57 (referred to as BCH-189) has approximately the same activity against HlV as AZT, with little toxicity. The (-)-cnantiomcr of the racemate BCH-I 89, known as 3TC, which is covered by U.S. Patent No. $,539,1161 iot o eat., is currently sold for the treatment of BTV in humans in the U.S- in combiniation with AZT.

It has also been disclosed that eis-2--hydroxymethyl-5-*5-fluorocytosin-I .yl).1,3.

oxathiolane has potent 141V activity. Scbinnzi, et at, "Selective Inhibition of Human Immxunodeficiency viruses by Raceruas and Enarniomers of (Hydroxymcthyl)-1 ,3-Qxatiolane-5-yl]Cytosine Antimiicrobial Agents and Chemotherapy, November 1992. pp. 2423-2431. See also U.S. PattNos. 5,210,085; 5,814,639; 5,728,575; 5,827,727; 5,914,33 1; WO 91/11186 and WO 92/14743.

WO 96/40164 filed by Emory University, UAI3 Research Foundation, and the Centre National de la Recherhe Scientitique discloses a number of f-L-2'X3-dideoxyntucloosides for the treatment of heptitis B.

WO 95/07287 also tiled by Em~ory University, UAB Research Foundation, and the Centre National de la Recherche Scientifique discloses 2' or 3 deoxy and 2',3'*-didcoxy-f-Lpentofiranosyl nucleosides for the treatment of HIV' infection.

W096/13512 filed by Genencor Internaional, Inc., and Lipitek, Inc., discloses the preparation of L-ribofizranosyl nucleosides as antitumor agents and vinacides.

W095/32984 discloses lipid esters of miaceoside mopophosphates as immunosuppresive drugs.

DE4224737 discloses cytosine nucleosides and their pharmaceutical uses.

Tsui, et in Biochemn. Pbarxnacol. 48(7). pages 1477-SI, 1994 discloses the effect of the anti-Hly agent 2'-P-D-F-2',3'-dideoxynucleoside analogs on the cellular content of mitochondrial DNA and lactat production.

Galvez, J. ChemIn f' Comnput. Sci. (1994), 35(5), 1198-203 describes molecular computation of P-D-3'-azido-2',3'-dideoxy-5-fluorocytidinc.

Mahnioudian, Phano. Research 43-6 (1991) discloses quantitative structureactivity relationship analyses of HIV agents such as P-D-3'-azido-2,'-dideoxy-5fluorocytidine.

U.S. Patent No. 5,703,058 disclome (5-carboxiinido or 5-flumno)-2',3'-unsaturatcd or 3'-modifled) pyrimidine nucleosides for the treatment of HIV and HBV infection.

2 COMS ID No: SMBI-00483657 Received by IP Australia: Time (Itm) 16:01 Date 2003-11-06

NO

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

00 In light of the fact that acquired immune deficiency syndrome and AIDS-related complex have reached epidemic levels worldwide, and have tragic effects on the infected patient, there remains a strong need to provide new effective pharmaceutical agents to treat these diseases that have low toxicity to the host It is an object of the present invention to provide a compound and method for the r treatment of human patients or other host animals infected with HIV.

O

Summary of the Invention A method for the treatment of HIV infection in humans and other host animals is disclosed that includes administering an effective HIV-treatment amount to the host of a P-Lor 3'-azido)-2',3'-dideoxy-5-fluorocytodine nucleoside or a pharmaceutically acceptablesalt, ester, or prodrug thereof, including a stabilized phosphate, administered either alone or in combination or alternation with another anti-HIV agent, optionally in a pharmaceutically acceptable carrier. In a preferred embodiment, the 2' or 3'-azido group is in the ribosyl configuration.

The disclosed or 3'-azido)-2',3'-dideoxy-5-fluorocytodine nucleosides, or pharmaceutically acceptable salts, esters, or prodrugs or pharmaceutically acceptable formulations containing these compounds are useful in the prevention and treatment of HIV infections and other related conditions such as Acquired Immune Deficiency Syndrome (AIDS), AIDS-Related Complex (ARC), persistent generalized lymphadenopathy (PGL), AIDS-related neurological conditions, anti-HIV antibody positive and HIV-positive conditions, Kaposi's sarcoma, thrombocytopenia purpurea and opportunistic infections.

These compounds or formulations can also be used prophylactically to prevent or retard the progression of clinical illness in individuals who are anti-HIV antibody or HIV-antigen positive or who have been exposed to HIV.

In one embodiment, the active compound is f-L-(2'-azido)-2',3'-dideoxy-5fluorocytodine (L-2'-A-5-FddC) or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula:

O

00

NHR'

~FR

RO

N

N

YF

c-

N

3

NHR'

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

In another embodiment, the active compound is P3-L-(3'-azido)-2',3'-dideoxy-5fluorocytodine L-3'-A-5-FddC) or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula:

NHR'

N FN

N

RO

O N

F

N

3

NHR'

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

In another embodiment, the or 3')-A-5-FddC nucleoside is administered in alternation or combination with one or more other compounds which exhibit activity against HIV, as described in more detail below. In general, during alternation therapy, an effective

NO

O dosage of each agent is administered serially, whereas in combination therapy, an effective dosage of two or more agents are administered together. The dosages will depend on absorption, inactivation, and excretion rates of the drug as well as other factors known to 0 0 those of skill in the art. It is to be noted that dosage values will also vary with the severity of the condition to be alleviated. It is to be further understood that for any particular i) subject, dosage regimens and schedules should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising OD the administration of the compositions. In one preferred embodiment, the compound is m administered in combination with AZDU.

O 10 Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of the application.

The terms "comprise", "comprises" and "comprising" as used throughout the specification are intended to refer to the inclusion of a stated component or feature or group of components with or without the inclusion of a further component or feature or group of components or features.

Brief Description of the Figures Figure 1 is an illustration of a general reaction scheme for the stereospecific synthesis of 3'-substituted p-L-dideoxynuceosides.

Figure 2 is an illustration of a general reaction scheme for the stereospecific synthesis of 2'-substituted p-L-dideoxynucleosides.

Figure 3 is an illustration of one process for the preparation of P-L-(3'-azido)-2',3'- (L-3'-A-FddC).

Figure 4 is an illustration of one process for the preparation of p-L-(2'-azido)-2',3'- (L-2'-A-FddC).

IO

O

Detailed Description of the Invention 00 A method for the treatment of HIV infection in humans and other host animals is disclosed that includes administering an effective amount of a or 3'-azido)-2',3'nucleoside (referred to below as or 3')-A-5-FddC") or a pharmaceutically acceptable salt, ester, or prodrug thereof, including a stabilized phosphate, either alone or in combination or alternation with another anti-HIV agent, optionally in a pharmaceutically acceptable carrier.

The compounds described herein can be used to treat AIDS and AIDS-related conditions including Acquired Immune Deficiency Syndrome (AIDS), AIDS-Related Complex (ARC), persistent generalized lymphadenopathy (PGL), AIDS-related neurological conditions, anti-HIV antibody positive and HIV-positive conditions, Kaposi's sarcoma, thrombocytopenia purpurea and opportunistic infections. The method of the present invention includes the use of an or 3')-A-5-FddC prophylactically to prevent or retard the progression of clinical illness in individuals who are anti-HIV antibody or HIV-antigen positive or who have been exposed to HIV.

As used herein, the term "substantially in the form of a single isomer" "substantially free of" or "substantially in the absence of refers to a nucleoside that is at least approximately 95% in the designated stereoconfiguration.

The term alkyi, as used herein, unless otherwise specified, refers to a saturated straight, branched, or cyclic, primary, secondary, or tertiary hydrocarbon of C 1 to Clo, 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 can be optionally substituted with one or more moieties selected from the group consisting of hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, or phosphonate, either unprotected, or protected as necessary, as known to those skilled in the art, for example, as taught in Greene, et al., "Protective Groups in Organic Synthesis," John Wiley and Sons, Second Edition, 1991. The term lower alkyl, as used herein, and unless otherwise specified, refers to a C 1 to C 4 ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, or t-butyl group.As used herein, 6-11-03;15;44 ;Blake Dawson Waldron ;613 95763111 IS/ 57 the term acyl refers to moiety of the formula wherein R' is alkyl; aryl, alkaryl, aralkyl, beteroaromatic, alkoxyalkyl including methoxymethyl; arylalkyl including benzyl; aryloxyalkyl such as phenoxymethyl; aryl including phenyl optionally substituted with halogen, C, to Ca alkyl or Ci to C 4 alkoxy, or the residue of an amino acid. The term acyl specifically includes but is not limited to 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.

The or 3')-A-5-FddC nucleoside can be converted into a pharmaceutically acceptable ester by reaction with an appropriate esterifying agent, for example, an acid halide or anhydride. The nucleoside or its phannaceutically acceptable prodrug can be converted into a pharmaceutically acceptable salt thereof in a conventional manner, for example, by treatment with an appropriate base or acid. The ester or salt can be converted into the parent nucleoside, for example, by hydrolysis.

As used herein, the term pharmaceutically acceptable salts or complexes refers to salts or complexes of the or 3')-A-5-FddC that retain the desired biological activity of the parem compound and exhibit minimal, if any, undesired toxicological effects. Nonlimiting examples of such salts are acid addition salts formed with inorganic acids (for example, hydrochloric acid, hydrobromic acid, sulfiric acid, phosphoric acid, nitric acid, and the like), and salts formed with organic acids such as acetic acid, oxalic acid, taarric acid, succinic acid, malic acid, ascorbic acid, benzoic acid, tannic acid, pamoic acid, alginic acid, polyglutamic acid, naphthalenesulfonic acids, naphthalenedisulfonic acids, and polygalacturonic acid; base addition salts formed with cations such as sodium, potassium; zinc, calcium, bismuth, barium, magnesium, aluminum, copper, cobalt, nickel, cadmium, sodium, potassium, and the like, or with an organic cation formed from N,N-dibenzylethylcnediamine, ammonium, or ethylenediamine; or combinations of(a) and a zin tannate salt or the like.

The term prodrug, as used herein, refers to a compound that is converted into the nucleoside on administration in vivo, or that has activity in itself. Nonlimiting examples are pharmaceutically acceptable salts (alternatively referred to as "physiologically acceptable salts"), and the 5' and N 4 acylated or alkylated derivatives of the active compound, as well as the 5'-monophosphate, diphosphate, or triphosphate derivatives or stablized phophate 7 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 14/ 57 pmdrugs (alternatively referred to as "physiologically or pharmaceutically acceptable derivatives") or phosphate lipid prodrugs, as described herein.

Modifications of the active compounds, specifically at the N 4 and 5'-0 positions, can affect the bioavailability and rate of metabolism of the active species, thus providing control over the delivery of the active species.

A preferred embodiment of the present invention is a method for the reatment of HIV infections in humans or other host animals, that includes administering an effective amount of one or more of an or 3')-A-5-FddC nucleoside selected from the group consisting of, Land L-3'-A-5-FddC, or a physiologically acceptable prodrug thereof, including a phosphate, 5' and or N 4 alkylated or acylated derivative, or a physiologically acceptable salt thereof, optionally in a pharmaceutically acceptable carrier. The compounds of this invention either possess anti-HIV activity, or ar metabolized to a compound or compounds that exhibit anti-HIV activity. In a preferred embodiment, the or 3')-A-5-FddC nucleoside is administered substantially in the form of a single isomer, at least approximately 95% in the designated stereoconfiguration.

Combination or Alternation Therapy It has been recognized that drug-resistant variants of HIV can emerge after prolonged treatment with an antiviral agent. Drug resistance most typically occurs by mutation of a gene that encodes for an enzyme used in the viral life cycle. Recently, it has been demonstrated that the efficacy of a drug against HIV infection can be prolonged, augmented, or restored by administering the compound in combination or alternation with a second, and perhaps third, antiviral compound that induces a different mutation from that caused by the principle drug. Alternatively, the pharmacokinetics, biodistribution, or other parameter of the drug can be altered by such combination or alternation therapy. In general, combination therapy is typically preferred over alternation therapy because it induces multiple simultaneous stresses on the virus.

The second antiviral agent for the treatment of HIV, in one embodiment, can be a revere transcriptase inhibitor (a which can be either a synthetic nucleoside (a "NRTI") or a non-nucleoside compound (a "NNRTIn). In an alternative embodiment, in the case ofHIV, the second (or third) antiviral agent can be a protease inhibitor. In other embodiments, the second (or third) compound can be a pyrophosphate analog, or a fusion 8 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 binding inhibitor. A list compiling resistance data collected in vitro and in vivo for a number 00 of antiviral compounds is found in Schinazi, et Mutations in retroviral genes associated with drug resistance, International Antiviral News, Volume International Medical Press 1996.

Preferred examples of antiviral agents that can be used in combination or alternation with the compounds disclosed herein for HIV therapy include 2-hydroxymethyl-5-(5fluorocytosin-1-yl)-1,3-oxathiolane (FTC); the (-)enantiomer of (cytosin-1-yl)-1,3-oxathiolane (3TC); carbovir, acyclovir, interferon, AZT, DDI, DDC, D4T, CI CS-92 (3'-azido-2',3'-dideoxy-5-methyl-cytidine), and P-D-dioxolane nucleosides such as f D-dioxolanyl-guanine (DXG), f-D-dioxolanyl-2,6-diaminopurine (DAPD), and f -Ddioxolanyl-6-chloropurine (ACP), MKC-442 (6-benzyl-1I-(ethoxymethyl)-5-isopropyl uracil.

Preferred protease inhibitors include crixovan (Merck), nelfinavir (Agouron), ritonavir (Abbot), saquinavir (Roche), and DMP-450 (DuPont Merck).

Nonlimiting examples of compounds that can be administered in combination or alternation with any of the or 3'-azido)-2',3'ddeoxy-5-fluorocytodines of the present invention include (I S,4R)-4-[2-amino-6-cyclopropyl-axnino)-9H-purin-9-yl]-2-cyclopentele- 1 -methanol succinate ("1592", a carbovir analog; GlaxoWelicome); 3TC: dideoxy-3'-thiacytidine (GlaxoWelicome); a-APA RI 8893: a-nitro-anilino-phenylacetamide; A-77003; C2 symmetry-based protease inhibitor (Abbott); A-75925: C2 symmetry-based protease inhibitor (Abbott); AAP-BHAP: bisheteroarylpiperazine analog (Upjohn); ABT- 538: C2 symmetry-based protease inhibitor (Abbott); AzddU: 3'-azido-2',3'-dideoxyuridine; AZT: 3 -azido-3'-deoxythymidine (GlaxoWeilcome); AZT-p-ddl: 3' -azido-3'deoxythymidilyl-(5',5')-2',3 '-dideoxyinosinic acid (Ivax); BH-AP: bisheteroarylpiperazine; BILA 1906: N- (I ,l-dimethylethyl)aminojcarbonyl)-4R-13pyridinylmethyl)thio]- I -piperidinyl]-2R-hydroxy-I1S-(phenylmethyl)propyljamino]carbonyl)-2-methylpropyl -2-quinolinecarboxamide (Bio Mega/Boehringer- Ingeiheimn); BRLA 2185: N-(1,1 -dimethylethyl)- I-[2S-112-2,6-dimethyphenoxy)- 1oxoethyl]amino]-2R-hydroxy -4-phenylbutyl]4R-pyridinylthio)-2-piperidinecarboxamide (Bio MegafBoehringer-Ingelheim); BM+5 1.0836: thiazolo-isoindolinone derivative; BMS 186,318: aminodiol derivative HIV- I protease inhibitor (Bristol-Myers-Squibb); d4API: 9- [2,5-dihydro-5-(phosphonomethoxy)-2-furanel]adenine (Gilead); d4C: 2' ,3 '-didehydro- 2',3 '-dideoxycytidine; d4T: 2',3 '-didehydro-3'-deoxythymidine (Bristol-Myers-Squibb); 8-11-O3;15:44 ;Blake Dawson Waldron ;i 8811#1/5 ;613 98783111 16/ 57 ddC; 2',3'-didcoxyeytidine (Roache); MEl! 2',3'-didcaxyinosinc (Bristol-Myers-Squibb); DMP-266: a I ,4-dibydro-2H-3, l-benzxawin-2-one; DMP'-450: {[4R-(4-a,5-a;6-b,7-b)I hexabydro -5,6-bis(hydroy)-I .3-bis(3-amino)phenyl~mcthyl)-4,7-bis(phexylniethyl)-2H-1 q3diazein-2--ore}-hisniesylate (Avid); DXG:(-)--D-dioxolane-guanosine (Triangle); EBUdM:5-etbyl-1-ethoxymediyl-6-(3,5-dimethylbenzyl)uracii; E-EBU: 5-ethyl-i -ethoxymethyl- 6-benzyluraeil; DS: dexaran sulfate; E-EPSeU: 1-(ethoxymethyl)-(6-phenylselenyi)-5ethyluracil:, E-EPU: I -(ethoxymctbyl)-(6-phenyi-.tho)-5.ethyluracil; FTC: O3-2',-didcoxy- 5-fluoro-3'-thiacytidine (Triangle); JiBY097: SA4-isopropoxcarboy4.mnctoxy-3.

(methylthio..zetbyl)-3,4-dihydroquinoxajin -2(1 H)-thione; KEPT; 1 hydwzxyethoxy)methyl]&-(phenyhthio)thymine; HIY-I ;humnan imnmunodeficiency virus type 1; 3M763: I, ,3-propenediyl)-bis--I,, teframceyclotcfradecane(JohnnMattbcy); 1M3 100:1,1 '41 ,4-phenylenebis-(mnethylene)]-bis-.1,4,8,1 1-tetraacyclptetsadecane(Jolmson Matthcy); KNI-272: (2S,3S)-3-omino-2-hydwoxy-4-pheuyibutyi acid-containing tripepdide; L-697,593; 5-ethyl-6-mcthyl-3-(2-phtbaliniida-ethyl)pyidin-2(1 l)-one; L-735,524: hydroxy-amninopentane amide IRN- protease inhibitor (Merck); L-697,661:3- -4divhloro-13-bnzxazol-2-yl)rncthylaxnino)-5-vthyl-&-metbylpyridin -2(1 11)-one; L-FDDC: (-)-B-L-5-fluoro-2',3'-dideoxycytidine; L-FDOC:(-)-BL-5-fluoro-doxolane cytosine; MKC442: 6-benzyl-1 -cthoxyinetby-$-isopropyluraicil (-EBU; Triauglecvltsubishfl; Nevlrapine:j I1-cyclopropyl-5,l I -dlbydro-4-merhyl-6H-dipyridol[3,2-b:2',3'-ediazepn-6-onc (Bochringer-lngclheirn); NSC64B400: 1-benzyloxymcthyl-5-ethyl-6-(lphapyridylthio)uwcil (E-BPU); _P9941: [2-pyridylacetyl-lePheAla-y(CHOH)]2 (Dupont Merck); PFA: phosphonofonnate (foscarnet; Asbra); PMIA: 9-(2phosphonylwethoxyetbyi)adenine (Gilead); PMPA: (R)-9-(2-phosphonylflethoxypropyl)adenine (Gilcad); Ro 31-8959: hydroxyethylamine derivative HIV-l1 prtast inhibitor (Roche); RI1-3 12: peptidyl proteas inhibitor, 1-(3s)-3-(n-alphabenyloxycrbonyl)--asparginyl).amlno-2-hydroxy-4-penylbuyl]n.et-utyl-.pralne aroide: 2720. 6 -chlowo-3hncimthyA4-iopropenyoxycaony)-3,4-dihydro-qunoxain 2(l H)thione; SC-5215 1: hydroxyctbyhire isostere protease inhibitor (Sere); SC-553 89A: hydroxyethyl-urea isoswerc protest inhibitor (Sere);- TI8C) R82150: tthydro-5-mexhyl-6-(3-methyl-2-butenyl)imidazo[4,S, I -jk][1,4]-benzodiazepin-2(1 thione (Janasn); TWO 82913: (4'-)-(SS)-4,S,6,7,-tetruiiydro-9-chloro-5-mezhyl-6-(3-nietl- 2-butcnyl)imaidazo[4,5, Ijkl-I,4]benzo-diazcpin-2(1 H>-thione (Janssen); TSAO-m3T4T2,5'- COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 17/ 57 bis-O-(tert-butyldimethylsilyl)-3'-spiro-5'-(4'-amino- 1 ',2'-oxathiole-2',2'.dioxide)]-b-Dpentofuranosyl-N3-nmthylthyminc; U901S2: l-[3-[(l-methylethyl)-amino]-2-pyridinyl-4- [[S-[(methylsulphonyl)-anino]-1H -indol-2ylcarbonyI]piperazine; UC: thiocarboxanilide derivatives (Uniroyal); UC-781 4 -chloro- 3 -(3-methyl-2-butenyloxy)penyl)-2-methyl-3furancarbothloanide; UC -82 -N-[4-chlor-3-(3-methyl-2-butenyloxy)phenyl]-2-methyl-3thiophenecarbothioamide; VB 11,328: hydroxyethyl-sulphonamid protease inhibitor (Vertex); VX-478: hydroxyethylsulphonramide protease inhibitor (Vertex); XM 323: cyclic urea protease inhibitor (Dupont Merck) or DMP-266 (cfavirenz, Sustiva).

Preparation of the Active Compounds Stereochemistry Since the 1' and 4' carbons of the sugar or dioxolanyl moiety (referred to below generically as the sugar moicty) of the nucleosides ae chiral, their nonhydrogen substituents and the pyrimidiuc or purine base, respectively) can be either cis (on the same side) or trans (on opposite sides) with respect to the sugar ring system. The four optical isomers therefore are represented by the following configurations (when orienting the sugar moiety in a horizontal plane such that the "primary" oxygen (that between the CI' and C4'-atoms is in back): or "cis" (with both groups which corresponds to the configuration of naturally occurring nucleosides, the D configuration), or cis (with both groups "down", which is a nonnaturally occwring configuration, the L configuration), "a "or "trans" (with the C2 substituent "up" and the CS substituent "down"), and trans (with the C2 substituenit "down" and the C5 substituent The active nucleosides ofthe present invention are in the P-L-configuration, with the azid group in the ribosyl configuration.

11 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15;44 ;Blake Dawson Waldron ;613 98783111 18/ 67 Nucleotide Prodrugs Any of the nucleosides described herein can be administered as a stabilized nuclcotide prodrug to increase the activity, bioavailability, stability or otherwise alter the properties of the nucleoside. A number of nucleotide prodrug ligands are known. In general, alkylation, acylation or other lipophilic modification of the mono, di or triphosphate of the nucleoside will increase the stability of the nucleotide. Examples ofsubstituent groups that can replace one or more hydrogens on the phosphate moiety are alkyl, aryl, steroids, carbohydrates, including sugars, 1,2-diacylglycerol and alcohols. Many are described in LR Jones and N.

Bischofberger, Antiviral Research, 27 (1995) 1-17. Any of these can be used in combination with the disclosed nucleosides to achieve a desired effect In one embodiment, the or 3')-A-5-FddC nucleoside is provided as lipophilic prodrug, a 5'-ether lipid or a 5'-phosphoether lipid. Nonlimiting examples of U.S. patents that disclose suitable lipophilic substituents that can be covalently incorporated into the nucleoside, preferably at the 5'-OH position of the nucleoside or lipophilic preparations, include U.S. Patent Nos. 5,149,794 (Sep. 22, 1992, Yatvin ct 5,194,654 (Mar. 16, 1993, Hostetler et al., 5,223,263 (June 29, 1993, Hostetler et 5,256,641 (Oct.

26, 1993, Yatvin et 5,411,947 (May 2, 1995, Hostetler et 5,463,092 (Oct. 31, 1995, Hostetler et 5,543,389 (Aug. 6, 1996, Yarvin et 5,543,390 (Aug. 6, 1996, Yatvin et 5,543,391 (Aug. 6, 1996, Yatvin et and 5,554,728 (Sep. 10, 1996; Basava et al.).

Foreign patent applications that disclose lipophilic substituents that can be attached to the or 3')-A-5-FddC nucleoside derivative of the present invention, or lipophilic preparations, include WO 89/02733, WO 90/00555, WO 91/16920, WO 91/18914, WO 93/00910, WO 94/26273, WO 96/15132, EP 0 350 287, EP 93917054.4, and WO 91/19721.

Additional nonlimiting examples of or 3')-A-5-FddC nucleosides are those that contain substituents as described in the following publications. These derivatized nucleosides can be used for the indications described in the text or otherwise as antiviral agents, including as anti-HIV agents. Ho, D.H.W. (1973) Distribution ofKinase and deaminase of lb-Drabinofiranosylcytosine in tissues of man and mouse. Cancer Res. 33, 2816-2820; Holy, A.

(1993) Isopolar phosphorous-modified nucleotide analogues. In: De Clercq Advances in Antiviral Drug Design, Vol. I, JAI Press, pp. 179-231; Hong, Nechaev, and West, C.R (1979a) Synthesis and antitumor activity of 1b-D-arabinofuranosylcytosine conjugates of cortisol and cortisone. Biochem. Biophys. Rs. Commun. 88, 1223-1229; Hong, 12 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron :1 6611#1/5 ;613 98763111 19/ 57 Nechaev, Kirisits, AJ. Buebbeit, DiJ. and West. C.R. (1980) Nucleoside conjugates as Potential antitumnor agents. 3. Synthesis and antitumor activity of I1-Darabinofblrannsyi)cytosie conjugates of corticosteriods and selected lipaphifir.pacohols- J Med Chem. 2S, 171-177; Hostetler, KY., Stuhmiller, Looting, H3R.M. van den Bosch, H. and Riehinan, D.D. (1990) Synthesis and antiretroviral activity of phospholipid analogs of azidothymidine and other antiviral nucicosides. J Biol Chem. 265,6112-6117; Hostetler, K.Y, Carson, D.A. and Richman, D.D. (1991); Phosphatidylazidothyrnidine! mechanism of anfiretrovirpl action in CEMt cells. J Rio! Chem. 266,11714-11717; Hostehler, KY., Korba, B. Sridhar, Gardener, VLv (I1994a) Antiviral activity of phosphatidyl-didcoxycytidine in hepatitis B-infected cells and enhanced hepatic uptake in nice. Antiviral Res. 24, 59-67; Hosteiler, K.Y, Richman, Sridhar, C.N. Feigner, P.L, Feigner, Ricci, Gardener, MYF. Selleseth, D.W. and Bll;s MYN. (1 994b) Pbosphadidylazidlothymidine and phosphatidylddC: Assessmn~t of uptake in mouse lymphoid tissues and mntiviral activities in human immun odeficiency virus-infected cells and in ratiacher leukemia virus-infected mice, IS Antimicrobial Agents Chemother. 38, 2792-2797; Hunston, RN.. Jones A.A. Mc~uigan, C., Walker, KtT., Balzarini, and De Clercq, E. (1984) Synthesis and biological properties of some cyclic phosphotriesters derived from 2'-dcoxy-5-fluorourldlne. J. Med. Chien. 27,440- 444. Ai, YJE, Moot Sciunti, Bischoff. P. and Luu, B. (1990); Monophosphoric acid diesters of 7b-bydroxycholesterol and of pyrimidine nucleosides as potential antitumor agents: synthesis and preliminuay evaluation of antitumnor activity. J Med Chem. 33, 2264- 2270; Jones, MeGuigan, Walker, Baizarini, J. and DeClerc, E. (1984) Synthesis, properties, and biological activity of some: nucleoside cyclic phosphoraniidatcs. J1 Chemt Soc. Perkin Trans. 1, 1471-1474; Juodica, B.A. and Smart, J. (1974) Synthesis of ditribonucicoside amino acid derivatives. Coil.- Czech. Cliem. Commn. 39,363-968; IYatok;, Jmai, Yarnaji, Kato, Saito, Kawada, and lImi, 5.41989) Alkylated cAMP derivatives; selective synthesis and biological activities. Nucleic Acids Ries.

Sym Stir. 21, 1-2; Koaokca, Uichida, R. and Yaznaji, N. (199 1) A convenient synthesis of adenosine cyclic phosphate (CAMP) bentyl and methyl triesters. Heterocycles 32, 135 1-1356; Kinchington, Harvey, SiJ., O'Connor, Jones, Devine, K.O., Tatylor-Robinson, Jefftics, DJ. and McGuigan, C. (1992) Comparison of antiviral effects of zidovudine phosphoraridate and phosphorodiamidate derivatives against HIV and ULV in vitro. Aniviral Chiem. Chemnothet. 3,107-112; Kodanrn, K, Morcxzumi, Saitch, L.I., 13 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-1 1-06 B-11-03;15:44 ;Blake Dawson Waldron ;i 8811#2/5 'F613 98783111 20/ 57 Kuninaca, Yashino. H. and Sancyoshi, M. (1 9S9) Antitunor activity and pharmacology of I -b-D-arabinofrranosylcytosine -5'-stearylphosphate; an orally active derivative of I -b-Darabinofunosylcyrosine. 3pm. J. Cancer Ret. 80, 679-685; Korty, M. and Engels, J. (1979) The effects of adenosine- and guanosine 3'Y-phosphoric and acid henayl esters on guineapig ventricular xnyocardluzn. Naunyn-Schmiedcbcrg's Arch. Phamiacol. 310, 103-111; Kumnar, Go;, Jones, A.S. Walker, R.N. Balzarini, J. and De Clercq, E. (1990) Synthesis and biological evaluation of sow'c cyclic phosphoramidate nucleoside derivatives.

Ji Med Chem. 33,2368-2375.: LeBec, and Huynh-Dinh, T. (199 1) Synthesis of lipophilic phosphate wriester derivatives of 5-fluorouridine and arabinocytidine as anticancer prodrugs.

Tetrhedron Lett. 32,6553-6556; Lichtenstein, 1, Barrier, fED. and Cohen, S.S. (3960) The j metabolism of axogenously supplied nacleotides by E.Scherichia coli, J. Bil. Chem. 235, 457-465; Lucihy, J1., Von Dacaiken, Friederich, I. Manthey, Zweifel, Schlatter, C.

ad Bona, M.H (19 91) Synthesis and toxicological properties of three naturally occurring c-yampitbioalkanes. Mitt. (3eg. Lebensmittelunters. Hyg. 72,131-133 (Chem. Absmn. 1$ 127093): McGuigan, C. Toilerlicid. S.M. and Riley, P.A. (1989) Synthesis and biological evaluation of some phosphate triester derivatives of the anti-viral drug Ara. Nucleic Acids Res. 17,6065-6075; McWSgan Devine, O'Connor, LiJ., Galpin, Jeffijes DJ.

and Kinchingion, D. (I1990a) Synthesis and evaluation of som~e novel phosphomamidate derivatives of 3'-azido-Y3-dcoxythymidine (AZT) as anri-HLIV compounds. Antiviral Chem.

Chemother. 1, 107-113; McGuigan, O'Connor, TiJ., Nicholls, 5kP Nickson, C. and Kinchingron, D. (I 990b) Synthesis and arni-HIV activity of some novel substituted dialkyl phosphate derivatives of AZT and ddCyd. Antiviral Chem. Chemother. 1, 355-360; McGuigan, Nicholls, S.R, O'Connor, and Kinchington, D. (1 990c) Synthesis of some novel dialkyl phosphate derivative of 3'-modified nucleosides as potential anti-AIDS drugs- Antiviral Checm. Chemofizer. 1, 25-33: McQui*a, Deviate, O'Connor, TiJ..

and Kinchington, D.(1991) Synthesis and anti-HIV activity of some halonikyl phosphoraiiate derivatives of 3'-azido-3'-deoxythymnidine potent activity of the trichiomoethyl methoxyalaninyl compound. AntiviralkRu. 15, 255-263; McCdgain, C., Pathirana Mahinood, Devine, K.G. and Hay, AJ. (1992) Aryl phosphate derivatives of AZT retain activity against mUV-i in cell lines which are resistant to the action of AZT, Antiviral Res. 17, 311-321; McGuigan, Pathirana, Choi, S.M., Kinchington, D. and O'Connor, T.i. (I 993a) Phosphoramidate derivatives of Al-T as 14 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 21/ 57 inhibitors of HIV; studies on the carboxyl terminus. Anliviral Chent Chemother. 4,97-101; McGuigan, Pathirana, RN., Balnrini, J. and De Clercq, E. (1993b) Intracellular delivery of bioactive AZT nucleotides by aryl phosphate derivatives of AZT. Med Chem. 36, 1048-1052.

The or 3')-A-5-PddC nucleoside in another embodiment can be provided as a ether lipid or a 5'-phospholipid ether, as disclosed in the following references: Kucer, L.S., N. Lyer, E. Leake, A. Raben, Modest D. and C. Piantadosi. 1990. Novel membrane-interactive ether lipid analogs that inhibit infectious IV- production and induce defective virus formation. AIDS Res Hum Retroviruses. 6:491-501; Piantadosi, J.

Marasco S.L. morris-Natschke, K.L. Meyer, F. Gumnus, J.R. Surles, K.S. Ishaq, L.S.

Kucera, N. lyer, CA. Wallen, S. Piantadosi, and E. Modest. 1991-Synthesis and evaluation of novel ether lipid nucleoside conjugates for anti-HIV activity. J Med Chem.

34:1408-1414; Hostetler, LY., D.D. Richinan, D.A. Carson, L.M. Stuhhmiller, G.M. T. van Wijk, and H. van den Bosch. 1992. Greatly enhanced inhibition of human immunodeficiency virus type I replication in CEM and HT4-6C cells by 31-deoxythymidine diphosphate dimyristoylglycerol, a lipid prodrug of 3 1-deoxythymidine. Antimicrob Agents Chemother.

36:2025-2029; Hostetler, KY., L.M. Stuhmiller, H.B. Lenting, H. van den Bosch, and D.D.

Richman. 1990. Synthesis and antirtroviral activity of phospholipid analogs of azidothymidine and other antiviral nucleosides. Biol Chem 265:6112-7.

The question of chair-twist equilibria for the phosphate rings of nucleoside cyclic 3 '5'-monophosphates. 1 HNMR and x-ray crystallographic study of the diasteromers of thymidine phenyl cyclic 3',5'-monophosphatc. J. Am. Chem. Soc. 109, 4058-4064; Nerbonne, Richard, Nargeot, J. and Lester, H.A. (1984) New photoactivatable cyclic nucleotides produce intacellularjumps in cyclic AMP and cyclic GMP concentrations.

Nature 301, 74-76; Neumann, J.M, Herv, Debouzy, JC., Guerra, FI., Gouyette, C., Dupraz, B. and Huynh-Dinh, T. (1989) Synthesis and trunsembrane transport studies by NMR of a glucosyl phospholipid of thymidine. J. Am. Chemn. Soc. 111, 4270-4277; Ohno, Tatsumi, Hirano, Imai, K. Miweguchi, Nakamra, Kosaka, Takatuski, Yamaya, Toyarna. Yoshida, Masaoka, Hashimoto, Ohshima, Kimura, Yamada, K. and Kimura, 1. (1991) Treatment of mylodysplastic syndromes with orally administered l-b-D-rabinofuranosylcytosinc -5'-stearylphosphate. Oncology 48,451455.

Palomino, Kessle, D. and Horwitz, J.P. (1989) A dihydropyridine carrier system for COMS ID No: SMBI-00483657 Received by IP Australia: rime 16:01 Date 2003-11-06 6-11-03;15:44 ;BtaKe Dawsor Waldrorn63Q7~ii#2/5 ;613 98783111 22/ 57 sustained delivery of 2'3 -dideoxynucleosides to the brain- J. Med. Chem. 32, 622-625; Perkins, 8amncy, Wiurock, Clark, Pit., Levi;, I LAmbert, Pettcway, S.L, Serafinowska, HT, BAly, Jackson, Harden, M.R. Ashton, Sutton, D., Harvey, and Brown, A.CG. (1993) Activity of BRL47923 and its oral prodrug, SB203657A against a rauseher murine leukemia virus infection in Mice. Antiviral Res. 20 (Suppl. 84; Piantadosi, Marasco, CJI., Jr., Moris-Nstschke, Meyer, Gumnus, Suites, iJJ, lshaq, KS., Kucera, L.S. Jyer, Wallen, Piantadosi, S. and Modest EJ. (1991) Synthesis and evaluation of novel ether lipid nuclcoside conjugates for anti-1-V-l activity.

J. Med. Chain. 34, 1408-1414; Pomnpon. Lefrbvrc, lnmbeh, Kahn, S. and Farquhar, D. (1994) Decomposition pathways of the moono- and bis(pivaloyloxyrnethyl) esters of azidothymidine-5'-monaphospbatc in cell extract and in tissue culture medium:, an application of the 'on-line ISRP-clcsning' HPLC technique. Antiviral Chemr. Chemother. 91-98; Postemark, T. (1974) Cyclic AMP and cyclic GM?. Amxu. Rev. Pharnacol. 14,23-33; Prisbe, Martin, McGee, Baker, Smee, D.F. Duke, A.13., Matthews, TER- and Verheyden J.P.J. (1986) Synthesis and antiherpes virus activity of phosphate and phosphonare derivatives of 9-R(1,3-dihydroxy-2-propoxy)metbyl] gunnine. J.

Med. Chai. 29, 671-675; Puccb, Gosselin, Lefebvre, Pompon, Auibertin, AJ4- Dirm, A. and Iinbach, (1993) Intracellular delivery of nucleoside monophosphate through a reductase-inediated activation procss. Antiviral Res. 22,155-174; Pugaeva, V.P., Klochkeva, Mashbits, F.D. and Eizengart, R-S. (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, R.L- (1984) The potential of nucleotide analogs as inhibitors of retrovimuses and tmrnorm Pharm. Res. 11-18; Rosowsky, AL, Kim.

Ross and J. Wick, M.M. (1982) Lipophilic; 5'-(alkylphosphatc) esters of I -b-flarabnofuranosyleytosine and its N'-acyl and 2.2'-anhydro-3'0-acyl derivatives as potenltial prodrugs. 1. Mcd. Clhem., 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, EJC, Roes, 10J. Matsushita, MacCuss, Hong, C.l. and West C.R (1982). Phospholipd-nucloside conjugates. 3. Syntsis and preliminary biological evaluation of I1-b-D-arabinoflnnosylcytosine 2-diacyiglycerols. J. Med. Chew. 25.1322-1329; SaffhiIJ, L.and Hume, W.J. (1986) The degradation of 5-lododeoxyurldine and 5-bromodeoxyurdine by serum from different 16 COMS ID No: SMBI-00483657 Received by IP Australia: Time (I-tm) 16:01 Date 2003-11-06

(NO

sources and its consequences for the use of these compounds for incorporation into DNA.

Chem. Biol. Interact 57, 347-355; Saneyoshi, Morozumi, Kodamna, Machida, J., 00 Kuninaka, A. and Yoshino, H. (1980) Synthetic nucleosides and nucleotides. XVI. Synthesis and biological evaluations of a series of 1-b-D-arabinofuranosylcytosine 5'-alkyl or 5 aryiphosphates. Chem. Phanm. Bull. 28, 2915-2923; Sastry, Nehete, Khan, S., Nowak, Plunkett, Arlmnghaus, R.B. and Farquhar, D. (1992) Membrane-permeable dideoxyuridine 5'-monophosphate analogue inhibits human immunodeficiency virus infection. Mol. Pharmacol. 41,441-445; Shaw, Jones, R.J. Arimilli, MRN, Louie, M.S., Lee, W.A. and Cundy, K.C. (1994) Oral bioavailability of PMEA from PM[EA prodrugs in male Sprague-Dawley rats. 9th Annual AAPS Meeting. San Diego, CA (Abstract). Shuto, Ueda, lImamura, Fukukawa, K. Matsuda, A. and Ueda, T. (1987) A facile one-step synthesis of 5'-phosphatidyinucleosides by an enzymatic two-phase reaction. Tetrahedron Lett. 28, 199-202; Shuto, Itoh, Ueda, Imamura, Kukukawa, Tsujino, M., Matsuda, A. and Ueda, T. (1988) A facile enzymatic synthesis of 5'-(3-snphospbatidyl)nucleosides and their antileukemic activities. Chem. Pharm. Bull. 36, 209-217.

One preferred phosphate prodrug group is the S-acyl-2-thioethyl group, also referred to as

"SATE."

A general process for the stereospecific synthesis of 3'-substituted P-Ldideoxynucleosides is shown in Figure 1. A general process for the stereospecific synthesis of 2'-substituted P-L-dideoxynucleosides is shown in Figure 2. A detailed synthesis of P-L-( 3'-azido)-2',3'-ideoxy--fluoroCytodine is provided in Figure 3 and in Example I below. A detailed synthesis of 2'-azido)-2',3'-dideoxy--fluorocytodile is provided in Figure 4 and in Example 2 below.

Example I Preparation of 3'-azido)-2',3'-dideoxy-5-fluorocytodine Melting points were determined in open capillary tubes on a Gallenkanip MFB-595- 010 M apparatus and are uncorrected. The U V absorption spectra were recorded on an Uvikon 931 (KONTRON) spectrophotometer in ethanol. 'H-NMR spectra were run at room temperature in DMSO-d 6 with a Bruker AC 250 or 400 spectrometer. Chemical shifts are given in ppm, DMSO-ds being set at 2.49 ppmn as reference. Deuterium exchange, decoupling experiments or 2D-COSY were performed in order to confirm proton assignments. Signal multiplicities are represented by s (singlet), d (doublet), dd (doublet of 6-11-03;15:44 ;Blake Dawson Waldron ,P613 96763111 24/ 57 doublets), t (triplet), q (quadruplet), br (broad), m (multiplet). All J-values are in Hz. FAB mass spectra were recorded in the positive- (FAB>0) or negative (FAB<0) ion inode on a JEOL DX 300 mass spectrometer. The matrix was 3-nitrobenzyl alcohol (NBA) or a mixture (50:50, v/v) ofglycerol and thioglycerol Specific rotations were measured on a Perkin- Elmer 241 spectropolarimeter (path length I cm) and are given in units of 10-1 deg cm2 g Elemental analysis were carried out by the "Service de Microanalyses du CNRS, Division de Vemalson" (France). Analyses indicated by the symbols of the elements or functions were within 0.4% of theoretical values. Thin layer chromatography was performed on precoated aluminium sheets of Silica Gel 60 F2u (Merck, Art. 5554), visualization of products being accomplished by UV absorbency followed by charring with 10% ethanolic sulfuric acid and heating. Column chromatography was carried out on Silica Gel 60 (Merck, Art. 9385) at atmospheric pressure.

l-(2-0-Acctyl-3,di-O-Benzoyl-p-L-Xylofuranosyl)-5-Fla rouracil (2) A suspension of 5-fluorouracil (5.0 g, 38.4 mmol) was treated with hexmnethyldisilazane (IHMDS, 260 mL) and a catalytic amount of ammonium sulfate during 18 h 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 1,2dichloroethane (260 mL). To the resulting solution was added l,2-di-O-acetyl-3,5-di-obenzoyl-L-xylofuranose 1 (11.3 g, 25.6 mmol) [Ref.: Gosselin, Bergogne, Imbach, "Synthesis and Antiviral Evaluation of P-L-Xylofuranosyl Nucleosides of the Five Naturally Occurring Nucleic Acid Bases", Jowrnal ofHeterocyclic Chemistry. 1993,30 (Oct.-Nov.), 1229-1233] in anhydrous 1,2-dichlorocthane (130 mL), followed by addition of trimethylsilyl trifluoromethanesulfonate (TMSTf, 9.3 mL, 51.15 mmol). The solution was stirred for 6 h at room temperature under argon atmosphere, then diluted with chloroform (1 washed with the same volume of a saturated aqueous sodium hydrogen carbonate solution and finally with water (2x 800 mL). The organic phase was dried over sodium sulphate, then evaporated under reduced pressure. The resulting crude material was purified by silica gel column chromatography [cluent: stepwise gradient of methanol in methylene chloride] to give 2 (11.0 g, 84% yield) as a white foam; p 96-989C; UV (ethanol): m 228 nm (e 25900) 266 nm (e 9000), 250 mn (8 7200); t H-NMR (DMSO-d): 8 11.1 (br s, 1H, NH), 8.05 (1H, H-6, Js-rs 6.8 Hz), 7.9-7.4 10H, 2 CsHCO), 5.99 1H, 18 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 96783111 25/ 57 J-t2 3.1 Hz), 5.74 (dd 1HH-3', J 3 2 -4.2 Hz and J 2.3 Hz). 5.54 I H, H-2', Jr-r Jr_- 2,9 Hz), 4.8-4.6 3H, H-5' and MS: FAB>0 (matrix CT) mnz 513 (M+Hf, 383 105 (CsHsCO; FAB<O (matrix 0T) m/z 511 469 (M-

CH

3 CO), 129 121 (CHsCO2)-; [alD 2- -91 0.88 DMSO); Anal CajH 2

FN

2 0p H, fluoraouracil 3 Hydrazine hydrate (2.80 mL, 57A mmol) was added to a solution of 1-(2-O-acetyl- 3,5-di-o-benzoyl-P-L-xylofuanosyl)-5-fluorouracil 2 9.80 &g 19.1 mmol) in acetic acid mL) and pyridine (150 mL). The resulting solution was stirred overnight at room temperature. Acetone (50 mnL) was added and the mixture was stirred during 2 h. The reaction mixture was concentrated to a small volume and partitioned between ethyl acetate (200 mL) and water (200 mL). Layers were separated and the organic phase was washed with a saturated aqueous sodium hydrogen carbonate solution (2x 200 niML), and finally with water (2x 200 mL). The organic phase was dried over sodium sulphate, then evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol in methylene chloride] to give pure 3 (7.82 g, which was crystallized from methylene chloride; mp 93-97C; UV (ethanol): 227 am (Pr 22800) 267 nrn (a 8200), 40 249 nm (a -5900); 'H-NMR (DMSO-d6): 8 11.9 (br s, 1H, NH), 8.06 IH. H-6, JJ.

6 s 6.9 Hz) 8.0-7.4 10H, 2 Cs1CO), 6.35 1H, OH-2', Jon-2' 3.8 Hz), 5.77 1I, Jr.r 3.3 Hz), 5.43 (dd, IH, J.z- 3.1 Hz and 1.9 Hz) 4.8-4.6 3, H-5' and H-51, 4.43 1H, J= 2.3 Hz); MS: FAB>0 (matrix 0) m/z 941 471 341 (Sf, 131

(BH

2 )t 105 (CsHsCO); FAB<O (matrix GT) mir 939 469 129 121 (CHsCO0 2 0 2 e -110 1.55 DM3SO).

19 COMS ID Na: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 B-11-03;15:44 ;Blake Dawson Waldron 'F13 96763111 26/ 57 1-(2-Dexy3,5-di-o-benzoyp-urL-thre pebtofuranosyl)--fluoromcil 0 To a solution of 1-( 3 ,5-di-O-benoyl-p-L-xylofuanosyl)-5-fluorouraci 3 (15.4 g, 32.7 mmol) in anhydrous acetonitrile (650 niL) were added O-phenyl chlorothionoformate (6.80 mL, 49.1 mmol) and 4-dimethylaminopyridine (DMAP, 12.0 98.2 mmol). The resulting solution was stirred at room temperature under argon during I h and then evaporated under reduced pressure. The residue was dissolved in methylene chloride (350 mL) and the organic solution was successively washed with water (2x 250 mL), with an icecold 0.5 N hydrochloric acid (250 mL) and with water (2x 250 mLt), dried over sodium sulphate and evapomrated under reduced pressure. The crude materlal 4 was co-evaporated several times with anhydrous dioxane and dissolved in this solvent (265 mL). To the resulting solution were added under argon tris(trimethylsilylslane hydride (12,1 mLt, 39.3 mmol) and a'-azoisobutyronitrile (AIBN, 1.74 g, 10.8 mmol). The reaction mixture was heated and stirred at 100OC for 2.5 h under argon,then cooled to room temperature and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol in chloroform] to give pure (13.0 g, which was crystallized from a diethyl other/methanol mixture; mp 182- I 4*C; UV (ethanol): 229 nm (E 25800), 269 run (z 9300), Xm-i 251 nm (e 6500); 'H-NMR (DMSO-T): 6 11.8 (br s, 1, NH), 8.05 1, H-6, J& 1 s 7.0 Hz), 8.0-7.4 (Im, 10H, 2 CdHisCO). 6.15 IH, Jr-r 7.4 Hz), 5.68 I H, Jr.-r J 4 42 Hz), 4.84.6 2H, H-5' and 4.6 1H, 3.0-2.8 1H, 2.5-2-3 (d, 111, J 14.8 Hz); MS: FAB>0 (matrix OT) m/z 455 (M+IH. 325 131 (BH2, 105

(C

6 HCO)f; FAB<0 (matrix GT) m/ 452 129 [a(c]D -125 (c 1.05 DMSO); Anal C23fl 9 FN20, H. N, F).

COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 27/ 57 1-(2-Deoxy-3,5-di-o-benzoyl--L, Bz 6 Lawesson's reagent (3.1 g, 7.70 mmcol) was added under argon to a solution of 5 g, 1.0 immol) in anhydrous 1,2-dichloroethane (200 mL) and the reaction mixture was stirred overnight under reflux. The solvent was then evaporated under reduced pressure and the residue was purified by silica gel column chromatography (eluent stepwise gradient of methanol in chloroform] to give the 4-thio intermediate 6 (80% yield) as a yellow foam; mp 178-179C; WUV (ethanol): X. 230 nm 24900), 273 nm (e 6900), 333 nm (a 19200), 258 nm (c 5900), 289 nm (a 5300); 'H-NMR (DMSO-dc): S 13.1 (br s, IM, NH), 8.10 1H, H-6, J6.s 4,6 Hz), 81-7.4 IOH, 2 CsHCO), 6.09 1f, Jr- 7.3 Hz), 5.68 1H, J 1 3-4 J3-.4- 4.1 Hz), 4.9-4.8 21, H-5' and H- 4.7 1H, 2.9 1H, 25 (mn, 1H, MS: FABE0 (matrix OT) mz 941 (2M+Hy, 471 325 (St, 147 (BHz), 10$ (CsHsCOf; FAB<D (matrix GT) m/z 469 145 121 (CsHsCO2J; [a]O 2 0 -271 0.90 DMSO); Anal C23H1FN 2 0S H, N, F).

1-(2-Deoxy-+L-*-ree-pcteo 7 N H A solution of this 4-thio intermediate 6 (1.0 ,2.13 mmol) in methanolic ammonia (previously saturated at -10"C and tightly stopped) (60 mL) was heated at 100*C in a stainless-steal bomb for 3 h and than cooled to PC. The solution was evaporated to dryness under reduced pressure and the residue co-evaporated several times with methanol. The crude material was dissolved in water and the resulting solution was washed four times with methylene chloride. The aqueous layer was evaporated uInder reduced pressure and the residue was purified by silica gel column chromatography [eluent: stepwise gradient of 21 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron ;613 98763111 28/ 57 methanol in methylene chloride]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and filtered through a unit Millex HV-4 (0,45 pmin, Millipore) to provide 0.44 g of 7 (84% yield) which was crystallized from an ethyl acetate/methanol nicxture; mp 199-201 0 C; UV (cthanol); 4= 226 nm (s 7700), 281 nm (E 8500), 262 ninm 6300); 'H-NMR (DMSO-ds): 7.99 I H, H-6, JFs 7.4 Hz), 7.7-7.4 (br d, 2H, NH 2 5.98 1I, J.I- 8.1 Hz), 5.25 1H, OH-3', Jon-r 3.4 Hz), 4.71 (t IR, 01H-5', JOH-s' 5.6 Hz), 4.2 1H, 3.8-3.6 (in. 3H. H-4', and 2.5 IH, 1.8 1H, MS: FA>O (matrix GT) mn/z 491 (2M+H, 246 130 (BH 2 FAB<0 (matrix m/z 489 244 128 [u]o 2 -21 0.92 DMSO); Anal CSH 12

FN

3 0. H, N, F).

22 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 29/ 57 1-(2-Deoxy-5-O-+butyldimethyl silyl-iL-tkreo-pentofuranosyl)- 8 HO N F Nij To a solution of 7 (1.69 g, 6.89 mmol) in dry pyridine (35 mL) was added dropwise under argon atmosphere t-butyldimethylsilyl chloride (135 g, 8.96 mmol) and the mixture was stirred for 5 h at room temperature. Then the mixture was poured onto a saturated aqueous sodium hydrogen carbonate solution (100 mL) and extracted with chloroform (3x 150 mL). Combined extracts were washed with water (2x 200 mL) and then dried over sodium sulphate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [ehzent stepwise gradient of methanol in methylene chloridc] to give pure (2.94 g, as a white solid: rp 177-179C; UV (ethanol); X.

241 nt (e 9900), 282 nm (a 10000), 1i, 226 nm (e 8200), 263 nm (a 7600); 'H NMR (DMSO-d 6 8 7.95 1f, H-6, J6. 7.3 Hz), 7.8-73 (br d, 2H, NH 2 6.00 (dd, 1H, H-l', Jr-2 6.1 Hz and Jrr-2-- 1.9 Hz), 5.3 (br s, 1H, 4.2 (br s, 11, 3.9-3.7 (mn, 3H, H-5' and 2.5 1, 1.81 (br d, 1, H-27, J 14.6 Hz), 0.86 9H, (CHa)C-Si), 0.05 61H, (CH3)2Si); MS (matrix GT): FAB>0 mix 719 (2M+fH, 360 130 115 (TBDMS) t FAB<0 m/z 717 (2M-1H), 358 128 [ia]D? -23 0.96 DMSO).

1-(2-Deoxy-3-O-mosyl-5-0-4-butyl dimethylsilyl-L-hre-pento Do 9 o A suspension of 8(0.70 1.96 mmol) in dry pyridino (30 mL) was stirred under argon and cooled to (rC. Methanesulfonyl chloride (MsCI, 0.46 mL, 5.88 mmol) was added dropwise and the reaction mixture stirred at 0*C for 5 h. Then the mixture was poured onto 23 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 30/ 57 ice/water (100 mLt) and extracted with chloroform (3x 100.mL). Combined extcts were washed with a 5% aqueous sodiumrn hydrogen carbonate solution (100 mL), with water (2x 100 mL), dried over sodium sulphate and evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [eluent stepwise gradient of methanol in toluene] to give pure 2 (056 g, 65%) as a white solid; mrop 83-84 0 C; UV (ethanol): A4. 242 nm (c 8500), 282 rim (c 8800), 225 nm (s 6400), 264 rnm (c 6300); 'H NMR (DMSO-ds): 8 7.8-7.3 (br d. 2H, NH2), 7.60 1H, H-6, JjS 7.0 Hz), 5.93 (dd, 1H, Ji'-2' 4.5 Hz and Jrz.- 2.0 Hz) 5.2 1H, 4.1 1, 3.9-3.7 2H, and 3.17 3H, CH 3 SO), 2.7 11, 2.1 (mi, 1, 0.99 9H,

(CH

3 0.05 6H, (CH 3 MS (matrix GT): FAB>0 nmtz 875 438 342 (M-CHSO3), 130 (3Hf; FAB<0 m/z 873 (2M-Hy, 436 128

(CH

3 SO); -28 0.96 DMSO).

1-(2,3-Dideoxy-3-azido--O--butyI dimethylaislyl-P-L-erythr-pento To a solution of9 (520 mg, 1.19 mmol) in anhydrous dimethylformamide (12 mL) was added lithium azide moistened with 10% methanol (300 mg, 5.31 mmoli). The reaction mixture was stirred at 100"C during 2.5 h, and then cooled to room temperature, poured onto ice/water (200 mL) and extraeted with chloroform (3x 100 mL). Combined extracts were washed with saturated aqueous sodium hydrogen carbonate solution (2x 100 mL), with water (5x 100 mL), and then dried over sodium sulphate and evaporated under reduced pressure.

The residue was purified by silica gel column chromatography [eluent: methanol in chloroformn] to give pure 10 (327 mg, which was crystallized from a diethyl ether/methanoI mixture: mp 146-147'C; UV (ethanol): 243 nm 8700), 283 nm (a 8400), 226 nm (c 7200), 264 n (c 6700); 'H NMR (DMSO-d): 8 7.90 I, 11-6, 36.

FS 7.0 Hz), 7.8-7.5 (br d. 2, NH 2 6.0 1I, H-l 4.3 IH, 3.9-3.7 (min, 3H, H-5' and 2.4-2.2 2H, H-2' and 0.87 91, (CH 3 0.05 6H, 24 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 31/ 7

(CH

3 MS (matrix GT): FAB>0 m/z 769 385 130 (BHa t FAB<O m/z 383 []oO -67 0.96 DMSO).

1-(2,3-Dideopy-3.azido-p-L-eryhro- 11 S A I M solution of tezratylammonium trifluoride in tetrahydrofuirane (TBAFTHF, 1.53 mL, 1.53 mmol) was added to a solution of 10 (295 mg, 0.67 mmal) in anhydrous THF (4 mL). The resulting mixture was stirred at room temperature for 1.5 h and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol in chloroform]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and filtered through a unit Millex HV-4 (0,45 gm, Millipore) to give pure 11 (199 mg, which was crystallized from ethanol: mp 188-1890C (lit.: mp 164-166*C for the D-enantiomer); UV (ethanol): .max 243 nm (e 8700), 283 nm (z 8100), %min 226 nm (a 7100), 264 nm (z 6500); 'H NMR (DMSOd4): 5 8.08 1H, H-6, Js. 7.3 Hz), 7.8-7.5 (br d, 2H, NH 2 6.0 11, 5.3 (br s, 1H, OH-5t), 4.4 (m 1H, 3.8 (mn, 1W, 3.7-3.5 211, H-S' and 23 (m, 21, H-2' and MS (matrix GT): FAB>0 m/z 811 725 (2M+2G+H, 633 541 (2M+IH), 363 271 142 (S t 130 (BH 2 FAB<Om/z 647 539 377 269 128 [)i20 -31 0.90 DMSO); Anal. (CHiFN 6 O3) C, H, N, F.

COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 00 oo Analytical data Compound Formula Anal Calculated Anal Found C H N F C H N F 2 C2H 21

FN

2 O 58.59 4.13 5.47 3.71 58.33 4.25 4.24 3.49 C3H,FN24 60.79 4.21 6.17 4.18 61.22 4.26 6.18 3.90 6 C2H 9

FN

2 o0S 58.71 4.07 5.96 4.04 58.25 4.10 5.91 4.00 7 CH 1 2

FN

3 0 4 44.08 4.87 17.17 7.75 43.87 5.13 16.81 7.42 11 CHIFN 6 0 3 40.00 4.10 31.10 7.03 40.35 3.83 3138 7.12 Example 2 Preparation of 2'-azido)-2',3'-dideoxy-5-fluorocytodine General procedures and instrumentation used have been described in Example 1 in the Experimental protocols part of the synthesis of the 3' isomer (3'-N 3 -P-L-FddC).

1-(2-O-acetyl-3-deoxy-5-O-benxoyl-ji-L-erythro-pentofuranosyl)-5-uorouracil 13

ACO

BZO- O- N

F

0 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 during 18 h under reflux. After cooling to room temperature, the mixture was evaporated under reduced pressure, and the residue obtained as a colourless oil was diluted with anhydrous 1,2dichloroethane (290 mL). To the resulting solution was added 1,2-di-O-acetyl-3-deoxy-S-O- 8-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 33/ 57 benzoyl-L-erythro-pentofiranose 12 (8.5 g, 26.4 mmol) [Ref.: Mathd& PhD. Dissertation, Universit6 de Montpellier II -Sciences et Techniques du Languedoc, Montpellier (France), September 13, 1994; Gosselin, Mathd, Bergogne, Aubertin, Kin, A.; Sommadossi, Schinazi, RF.; Imbach, and/or 3'-doxy-fl-L-pentofranosyl nucleoside derivatives: stereospecific synthesis and antiviral activities," Nucleosides Nuleoides 1994, 14 611-617] in anhydrous 1,2-dichloroezhane (120 mL), followed by addition of trimethylsilyl trifluoromethanesulfonate (TMST# 9.6 mL, 52.8 mmol). The solution was stirred for 5 h at room temperature under argon atmosphere, then diluted with chloroform (200 mL), washed with the same volume of a saturated aqueous sodium hydrogen carbonate solution and fally with water (2x 300 mL). The organic phase was dried over sodium sulphate, then evaporated under reduced pressure. The resulting crude material was purified by silica gel column chromatography [cluent: stepwise gradient ofmethanol in methylene chloride] to give pure 13 (8.59 g, which was crystallized from toluene: mp 65-68"C; UV (ethanol): 1 228 mp (e 11200) 268 nm (c 14000), X 1 ,,242 nm (a 7800); 1 NMR (DMSO-d6): 8 11.9 (br s, 1H,NH), 8.0-7.5 6, CJHsCO and 5.8 1I, 53 4.6-4.5 3H, H-5' and 2.4-2.3 1H, 2.1- 4H, H-3" and CHsCO); Ms (matrix GT): FAB>0 m/z 393 (M+H)t 263 105 (CgHsCO-; FAB<O m/z 391 331 (M-[CH 3

CO

2 129 121 (C6HsC04; [aIDo -8 (c.1.00 DMSO); Anal. (CjsHg 7 FN207; 21 C7H,) C, H, N F.

1-(3-Deoy-5-O-benzoyl-L-erythro-pentofuranosyl)-5fluoronracil 14

F

To a solution of 13 (5.90 g, 15.0 mmol) in tetrahydrothrane (THF, 175 mL). was added sodium methoxide (2.84 g, 52.6 mmol). The resulting suspension was stirred at room temperature during 5 h and then neutralized by addition ofDowex 50 W X 2 (IF form). The 27 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 34/ 57 resin was filtered and washed with warm methanol, and the combined filtrates were evaporated to dryness. Column chromatography of the residue on silica gel [eluent: stepwise gradient of methanol in methylene chloride] afforded 14 (4.11 g, which was crystallized from a mathylene chloride/methanol mixture: mp 154-156°C; UV (ethanol): 226 nm (a 23000), 268 nm (a 16000), 246 nm (e 8900); 'H NMR (DMSO-d 6 6 11.8 (br s, 1H, NH), 80-7.5 6H, C6HsCO and 5.6 (br s, 2H, H-l' and 4.5 3H, H-5' and 4.3 1H, 2.1-2.0 1H, 1.9 IH, MS (matrix GT): FAB>0 m/z 701 (2M+HI, 351 221 131 (BH 2 105 (CsHsCO)*; FAB<0 m/z 1049 699 441 349 129 121 (C6HsCO 2 -3 1.04 DMSO); Anal. (CifHis 5

FN

2 0) C, H, N, F l-(3-Deoxy-5-O-benzoyl-p-L-threo-pentofuransyl)-5-flnorouraci

HN\

Dicyclohxylcarbodiimide (DCC, 3.53 g, 17.1 mmol) and dichloroacetic acid (0.235 mL, 2.56 mmol) were added to a solution of 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 during 4 h 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 during 1 h and then filtered to eliminate precipitated dicyclohexyuea (DCU). The filtrate was washed with brine (3x 300 mL), with a saturated aqueous sodium hydrogen carbonate solution (20 300 mL) and finally with water (3x 200 mL) before being dried over sodium sulphate and evaporated under reduced pressure. The resulting residue was co-evaporated several times with absolute ethanol and dissolved in a mixture of absolute ethanol (31 mL) and anhydrous benzene (15 mL). The resulting solution was then cooled to O'C and sodium borohydride (NaBH4, 0.32 g. 8.56 mmol) was added. The 28 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 35/ 57 reaction mixture was stirred at room temperature under argon during I h and diluted with ethyl acetate (300 mL) filtered. The filtrate was washed with a saturated aqueous sodium chloride solution (3x 300 mL) and with water (20 200 mL) before being dried over sodium sulphate and evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [aluent: stepwise gradient of methanol in chloroform] to give pure 15 (1.10 g, as a white foam: mp 171-1720C; UV (ethanol): 228 run (a 14700) 270 nm (e 9100), in 248 nm (s 5000); 'H NMR (DMSO-d): 8 11.8 (br s, IH, NH), 8.0-7.5 6H, C4HCO and 5.90 (dd, 1H, H-lI', Jra-* 4.1 Hz and Jr-Fs 1.8 Hz), (br s, 1, 4.7 (br q, 1I, H4', J= I11.7 Hz and J 7.0 Hz). 4.4-4.3 3H, H- 5' and 2.4 1, 1.9-1.8 (mn, 1H, MS (natrix GT): FAB>0 m/z 701 (2M+Hy, 351 221 131 (BH 2 f, 105 (CaHSCOt; FAB<0 m/r 1049 (3M-H), 699 (2M-Hy, 349 129 121 (CsH 5 COjE; [aO= -101 0.70 DMSO).

1-(2-0-acetyl-3-deoxy-5- buzoy -threo-puatefuranosyl)--fluorouraclI 16 0

F

0 Acetic anbydride (0.88 mL, 9.28 mmol) was added under argon to a solution of (2.50 g, 7.14 mmol) in dry pyridine (50 mL) and the resulting mixture was stirred at room temperature for 22 h. Then, ethanol was added and the solvents were evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent stepwise gradient of methanol In mthylene chloride] to give pure 16 (2.69 g, 96%) as a white foam; mp 68-70C (foam); UV (ethanol) 239 nm 15000) 267 n 8800), Irn" 248 nm 5600); 'H NMR (DMSO-d 6 8 ppm 11.9 (br s, 1, NH), 8.1-7.5 6H, CHCO and 6.10(d, I1, J-.

2 4.3 Hz), 5.4 1, 4.6-4.4 (m, 311, H-S' and 2.6 11, 2.03 1, 1,86 311, CH 3 CO); MS (matrix 0T): FAB>O ml 785 393 263 (Sf, 131 (BH 2 f, 105 (CHCOf, 29 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15;44 ;Blake Dawson Waldro6 ;613 98763111 36/ 57 43 (CHiCOV FABSO m x 391 (M-HY, 129 (By, 121 CC 6

H

5

CO

2 y, 59 (CH 3

CO

2 [4,20= 81 0.95 DMSO).

1-(Z-O-acetyl3-deoxy-ooy* -trO-penournyl)-4-tha5 Ioo fafl1 OZOc

S

Lawesson's reagent 1 .9 g, 4.69 mmol) was added under argon to a solution of 16 (2.63 g, 6.70 inmol) in anhydrous I,2-dichloroethane (165 ml) and the reaction mixture was stirred overnight under refux. The solvent was then evaporated under reduced pressure and the residue was purified by silica gel column chromatography [eluent: stepwisc $radiant of methanol in methylene chloride] to give the 4-thio derivative 17 (2.65 g, 96%/ yield) a a yellow foam; mp 78-79 9 C (fbam) UV (ethanol) Z 4 230 urn 15900) 334 nn 15600). 288 rn 3200); 'H NMR (DMSO-dc) ppm 13.2 (Er s, 11, NH), 8,1- 6H, C 6 HCO and 6.03 111, Ja*.r- 4.3 Hz), 5.4 1, 4.7-4.4 3H, H-5' and 2.6 iF, 2.0 1- 1.84 31, CH 3

CO);

MS (matrix UT): FAB>) m/x 409 (MIH 263 147 (BH 2 105 (C6HsC0)+, 43

(CH

3 CO)+ FABO mIx 407 (M-Hy, 145 121 (C 6 HsC 2 %Y 59 (CH 3

CO

2 Y -155 1.00 DMSO).

I-(3-a eoy-p-L-threo-pntofuranosy l)-4-tnrocygosinc 18 NH2 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;16:44 ;Blake Dewson Waldron ;613 98783111 37/ 57 A solution of the 4-thio derivative 17 (0-86 g, 2.19 mmol) in methanolic ammonia (previously saturated at -10"C and tightly stopped) (44 mL) was heated at 100 0 C in a stainless-steel bomb for 3 h and then cooled to 0*C. The solution was evaporated to dryness under reduced pressure and the residue co-evaporated several times with methanol, The S crude material was dissolved in water and the resulting solution was washed four times with methylene chloride. The aqueous layer was evaporated under reduced pressure and the residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol in chloroform]. Finally, the appropriate ftactions were evaporated under reduced pressure, diluted with methanol and filtered through a unit Millex HV-4 (0.45 pm, Millipore) to provide 0.46 g of 18 (86% yield) which was crystallized from a methylene/metano mixture; mp 137-138"C; UV (ethanol) 240 nm 8300) 284 nm 8100), 226 nm (e 7300) 263 rn 5500); 'H NMR (DMSO-d) 6 ppm 8.34 IH, 14-6, J.r- 7.5 Hz), 7.7-7.4 (br pd, 2H, NH 2 5.83 (dd, 11, Jir.2- 4 4 Hz, Jri'- 1.9 Hz), 5.22 1H, OH-2', Jos0W= 5.1 Hz), 5.15 1H, OH-5', Jo-= JOH-5- 4 8 H1), 4.3 1H, 4.0 1H, 3.6-3.5 (in,2H, H-S' and H-51 2.2 IH, 1.7 (m, 1H, MS (matrix GT): FAB>0 m/ 491 (2M+H)t 246 (MH) 130 FAB<0 m'z 244 128 [aoD 20 -135 0.89 DMSO). Elemental analysis, C 9

H,

2

FN

3 0 4 'A H 2 0; Cal, 42.52; H= 5.15; N= 16.53; F= 7.47; Found: C- 43.16; H= 532; N= 16.97; F= 6.92.

l-( 3 -Deoxy-S-O-t-butyldimetbylsilyl-L-threo-pentofaranosylS-fluorocytosine 19 hTM 9O-O\

NH

31 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 96783111 38/ 57 To a solution of (1.38 g, 5.63 mmol) in dry pyridine (30 mL) was added dropwise under argon atmosphere t-butyldimnethylsilyl chloride (1.10 g, 7.32 mmol) and the mixture was stirred for 10 h at room temperature. Then the mixture was poured onto a saturated aqueous sodium hydrogen carbonate solution (100 mnL) and extracted with chloroform (3x 150 mL).

Combined extracts were washed with water (2x 200 mtnL) and then dried over sodium sulphate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent stepwisc gradient of methanol in methylene chloride] to give pure 19 (1.74 86% yield) as a white solid: mp 202-2041C; UV (ethanol): 4 241 rnm (a 7800). 284 mn (s 7800), 226 nm (a 6600), 263 nm (a 5400); 'H NMR (DMSO-d): 8 7.77 1H, H-6, J.ps 7.1 Hz), 7.7-7.3 (br d, 2H, NH 2 6.88 (dd, 1H, 4.9 Hz and Jr-ps 1.9 Hz), 5.24 IH, OH-3', Joi.2 4.6 Hz), 4.4 (in, 11, 4.0 1H, H- 3.8-3.7 (in, 21H, H-5' and 2.2 1H, 1.7 IH, H-3D, 0.84 9H, (CHsbC-Si), 0.06 61H, (CH3)2Si); MS (matrix 0T): FAB>0 nz 1437 (4M+H, 1078 (3M+H, 719 (2M+H, 360 (M+H)t 231 130 (BHh, 115 (TBDMSf; FAB<0 m/z 1076 717 (2M-Hy, 358 (M-HY, 128 [a)J20 -107 0.88 DMSO).

1-(3-Deoxy-2-O-mesy1-5-O4-buty dimethlylly -hreeo-pentofuranosylyfluorocytosine Mao TBDMSO -yN 1 N4 A suspension of 19 (1.70 g, 4.73 mmol) in dry pyridie (80 mL) was stirred under argon and cooled to OaC. Methanesulfonyl chloride (MsCI, 1.21 mL, 1 5.6 rmmol) was added dropwise and the reaction mixture stirred at r*C for 5 h. Then the mixture was poured onto ice/water (300 mL) and extracted with chloroform (3x 300 mL). Combined extracts were washed with a 5% aqueous sodium hydrogen carbonate solution (300 mL), with water (2x 32 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-08 6-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 39/ 57 300 mL) and then dried over sodium sulphate and evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography (cluent stepwise gradient of methanol in toluene] to give pure 20 (1.41 g, 68% yield) as a white solid: mnp 75-76 OC; UV (ethanol): A. 243 nm (a 8100), 282 m (E 7300), Xjj 225 nm (s 6000), 265 em (a 6000); 'H NMR (DMSO-4): 8 7.9-7.6 (br d, 211, NH2), 7.85 IH, H-6, ps 7.0 Hz), 6.08 (dd, 1, 1 rt- 5-2 Hz and JT-FS 1.6 Hz), 5.4 1H, 4.1 1, 3.9 (nm, 11, 3.7 3.11 3H, CH 3 SO2), 2.47 1, H- 2.0 1H, 0.85 9H, (CHs)3C-Si), 0.05 6, (CH 3 2 Si); MS (matrix GT): FAB>O m/z 1312 875 438 309 (Sr, 130 (BH2); FAB<O mr/z 1310 873 (2M-Hy, 436 128 95 (CH 3 SOY; [o1? -84 0.84

DMSO).

-(2,3-Dideoxy-2-azdo-5s--butydimethbylsilyl-iLayrop.ntofuranosyl)Sfierocytine 1 N3

TSDMSON

NH

2

T

o a solution of20 (442 ing, 1.01 mmol) in anhydrous dilmethylfarmamide (12 mL) was added lithium azide moistened with 10% methanol (265 mg, 4.87 mmol). The reaction mixture was stirred at O00OC during 2.5 h. and then cooled to room temperature, poured onto ice/water (200 mL) and extracted with chloroform (3x 100 mL). Combined extracts were washed with a saturated aqueous sodium hydrogen carbonate solution (2x 100 mL), with water (Sx 100 mL) and then dried over sodium sulphate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent methanol in chloroform] to give pure 21 (291 mg, 75% yield) as a white solid: mp 147-148"C; 33 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron ;613 98763ill 40/ 57 UV (ethanol): 242 rim (a 7700), 283 rm (c 7400), 226 nmn (s 6600), 264 m (a 5800); 'H NMR (DMSO-4): 88.05 (4 IH, H-6, .164s 7.0 Hz), 7.9-7.4 (br d,21-1 NH 2 5.7 (br a, IH, H-i')7 4.37 (4 1, J 3 r 5.5 Hz), 4.3 11, 4. 19,14-5'), 3.7 IHH-5"), 2.0 (m I 1.8 lH, 0.88 91L, (CH3)C-Si), 0.05 6H,

(CH

3 MS (matrix GT): FA>O nih 769 385 130 (SHzf; ,FABO rnz 1151 767 21-Hf, 383 128 [a]?20 +25 0.95 DMSO).

Ji-(2d-Ddeoxy- 2 -azdo--Iro-pcntofur oosy1)-Sfluoreytosjne 22(2'-N-p-L-5- FddC)

N

3 yN

NH

2 A 1 M solution of tetmbutylamioniu trifluoride in tetrahydrofirane (TRAFHE, 1.90 mL, 1.90 inmol) was added to a solution oi21 (480 mg, 1.25 mmol) in anhydrous THE (8 mL) The resulting mixture was stirred at room teinpeaturr for 1.5 h and evaporated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: stcpwise gradient of methanol in chloroform]. Finally, the appropriate fractions were evaporated under reduced pressure, diluted with methanol and 5ltezmd through a unit Millex HVA (0.45 pm, Mihlipur) to give pure 22 (304 mg, 90% yield), which was crystallized from ethanol: mp 219-221'C; UV (ethanol): 241 ra (s 7700), 284m (a 7300), ma 225 rIm (a 6500), 263 un (e 5400); 'H NMR (DMSO- 6 8 8.31 (d 18. H-6. J6p 3 7.4 Hz), 7.9- 7-4 (br d,2H, NH2),5.65 IH,H-1') 522 (br; 1s 4.35 lH, Jr-3 5.6 Hz), 4.2 (mn, I, 3.8 (ra, 1H, 3.6 1, H-Sj, 2.1 11 1.8 1H, MS (matrix 01): FABO rih 541 363 (M+GHrt 271 130 (BH2+; FABcO m/k 539 (21-H, 269 128 +29 0.85 DMSO); Anal.

(CHl ,FN60O) C, N, F 34 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron ;613 96763111 41/ 57 Analytical data Fornula Anal. calclated Anal. foamd Compd C H N F C H N F 13 CaH 1 7

FN

2 0 7 2/3 C 7 H. 59.99 4.96 6.18 4.19 59.60 4.96 6.02 3,76 14 C, 6 HiSFN 2 0 6 54.86 4.32 8,00 5.42 54.75 4.16 7.78 5.49 22 CJH 1

FN

6 0O 40.00 4.10 31.10 7.03 40.07 4.16 31.10 6.99 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15;44 ;Blake Dawson Waldron -613 96763111 42/ 67 Anti-HIV Activity of the Active Compounds Antiviral compositions can be screened in vitro for inhibition of HIV by various experimental techniques. One such technique involves measuring the inhibition of viral replication in human peripheral blood mononuclear (PBM) cells. The amount of virus produced is determined by measuring the quantity of viruscoded reverse transcriptase (RT), an enzyme found in retroviruses, that is present in the cell culture medium.

Three-day-old phytohemagglutinin-stimulated PBM cells (10' cells/ml) from hepatitis B and HIV-1 seronegative healthy donors were infected with HIV-1 (strain LAV) at a concentration of about 100 times the 50% tissue culture infectious done (TICD 50) per ml and cultured in the presence and absence of various concentrations of antiviral compounds.

Approximately one hour after infection, the medium, with the compound to be tested (2 times the final concentration in medium) or without compound, was added to the flasks ml; final volume 10 ml). AZT was used as a positive control. The cells were exposed to the virus (about 2 x 10s dpm/ml, as determined by reverse transcriptase assay and then placed in a CO 2 incubator. HIV-1 (strain LAV) was obtained from the Centers for Disease Control, Atlanta, Georgia. The methods used for culturing the PBM cells, harvesting the virus and determining the reverse transcriptase activity were those described by McDougal et al. (J Immun. Meth. 76, 171-183, 1985) and Spira etaL., Clin. Mth. 25, 97-99, 1987), except that fungizone was not included in the medium (see Schinazi, et al, Antimicrob. Agents Chemother. 32, 1784-1787 (1988); Antimicrob. Agents Chemother., 34:1061-1067 (1990)).

On day 6, the cells and supernatant were transferred to a 15 ml tube and centrifuged at about 900 g for 10 minutes. Five ml of supernatant were removed and the virus was concentrated by centrifugation at 40,000 rpm for 30 minutes (Beckman 70.1 Ti rotor). The solubilized virus pellet was processed for determination of the levels of reverse transcriptase.

Results are expressed in dpm/ml of sampled supernatant. Virus from smaller volumes of superatant (1 mi) can also be concentrated by centrifugation prior to solubilization and determination of reverse transcriptase levels.

The median effective (ECso) concentration was determined by the median effect method (Antimicrob. Agents Chemother. 30,491-498 (1986). Briefly, the percent inhibition of virus, as determined from measurements of reverse transcriptase, is plotted versus the 36 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 43/ 57 micromolar concentration of compound. The ECSa is the concentration of compound at which ther is a 50% inhibition of viral growth.

Mitogen stimulated uninfected human PBM cells (3.8 x tOS cells/mi) were cultmed in the presence and absence of drug under similar conditions as those used for the antiviral assay described above. The cells were counted after six days using a hemacytometer and the trypan blue exclusion method, as described by Schinazi et al., Antimicrobial Agents and Chemotherapy, 22(3), 499 (1982). The IC50 is the concentration of compound which inhibits of normal cell growth.

Example 3 Anti-IUV Activity of or The ant-HIV activity of L-2'-A-5-FddC and L-3'-A-S-FddC was tested in CEM and PBM cells. The results are provided in Table 1.

Table 1I Compound Antivlrl Activty Cytotoaxiclty S.ltiamty tadex EC, (pM) I C0 (jpM) IC, IEC L-2'-A-S-Pddc 390 >100

(CEM)

0.29 >100 >344

(CEM)

1.00 >100 >100

(PBM)

0.05 >100 >2647

(PBM)

Preparation of Pharmaceutical Compositions Humans suffering from any of the disorders described herein, including AIDS, can be treated by administering to the patient an effective treatment amount of or FddC as described herein, or a pharmaceutically acceptable prodrng or salt thereof in the 37 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 98783111 44/ 57 presence of a pharmaceutically acceptable carrier or diluent. The active materials can be administered by any appropriate route, for example, orally, parenterally, intravenously, intradermally, subcutaneously, or topically, in liquid or solid form.

The active compound is included in the pharmaceutically acceptable carrier or diluent in an amount sufficient to deliver to a patient a therapeutically effective amount of compound to inhibit viral replication in viv, without causing serious toxic effets in the patient treated.

By "Inhibitory amount" is meant an amount of active ingredient suffcient to exert an inhibitory effet as measured by, for example, an assay such as the ones described herein.

A preferred dose of the compound for all of the above mentioned conditions will be in the range from about I to 50mg/kg, preferably I to 20mg/kg, of body weight per day, more generally 0.1 to about 100 mg per kilogram body weight of the recipient per day. The effective dosage range of the pharmaceutically acceptable prodrug can be calculated based on the weight of the parent nucleoside to be delivered. If the prodrug exhibits activity in itself, the effective dosage can be estimated as above uing the weight of the prodrug or by other means known to those skilled in the art.

The compound is conveniently administered in unit any suitable dosage form, including but not limited to one containing 7 to 3000 mg, preferably 70 to 1400 rg of active ingredient per unit dosage fon. A oral dosage of 50-1000 mg is usually convenient, and more typically 50 to 500 mng.

Ideally the active ingredient should be administered to achieve peak plasma concentrations of the active compound of from about 0.2 to 70 pM, preferably about LO) to 0 pM. This may be achieved, for example, by the intravenous injection of a 0.1 to 5% solution of the active ingredient, optionally in saline, or administered as a bolus of the active ingredient.

The concentration of active compound in the drug composition will depend on absorption, inactivation, and excretion rates of the drug as well as other factors known to those of skill in the art. It is to be noted that dosage valu will also vary with the severity of the condition to be alleviated. It is to be further undcrstood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that the concentration ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed composition. The active ingredient 38 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 6-11-03;15:44 ;Blake Dawson Waldron ;613 96783111 46/ 57 may be administered at once, or may be divided into a number of smaller doses to be administered at varying intervals of time.

A preferred mode of administration of the active compound is oral. Oral compositions will generally include an inert diluent or an edible carrier. They may be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules. Phannaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition.

The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring. When the dosage unit form is a capsule, it can contain, in addition to material of the above type, a liquid carrier such as a fatty oil. In addition, dosage unit forms can contain various other materials which modify the physical form of the dosage unit, for example, coatings of sugar, shellac, or other enteric agents.

The compound can be administered as a component of an elixir, suspension, syrup, water, chewing gum or the like. A syrup may contain, in addition to the active compounds, sucrose as a sweetening agent and certain preservatives, dyes and colorings and flavors.

The compound or a pharmaceutically acceptable derivative or salts thereof can also be mixed with other active materials that do not impair the desired action, or with materials that supplement the desired action, such as antibiotics, antifimgals, antiinflammatories, protease inhibitors, or other nucleoside or nonnucleoside antiviral agents. Solutions or suspensions used for parenteral, intradermal, subcutaneous, or topical application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, 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 ethylenediamineteatacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment oftonicity such as sodium 39 COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 8-11-03;15:44 ;Blake Dawson Waldron 'P613 9763111 46/ 57 chloride or dextrose. The parental preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

If administered intravenously, preferred carriers are physiological saline or phosphate buffered saline (PBS).

In a preferred embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylenc vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylacetic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially from Alza Corporation.

Liposomal suspensions (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) are also preferred as pharmaceutically acceptable carriers. These may be prepared according to methods known to those skilled in the art, for example, as described in U.S. Patent No. 4,522,811. For example, liposome formulations may be prepared by dissolving appropriate lipid(s) (such as stearoyl phosphaidyl ethanolamine, stearoyl phosphatidyl choline, arachadoyl phosphatidyl choline, and cholesterol) in an inorganic solvent that is then evaporated, leaving behind a thin film of dried lipid on the surface of the container. An aqueous solution of the active compound or its monophosphate, diphosphate, and/or triphosphate derivatives is then introduced into the container. The container is then swirled by hand to free lipid material from the sides of the container and to disperse lipid aggregates, thereby forming the liposomal suspension.

This invention has been described with reference to its preferred embodiments.

Variations and modifications of the invention, will be obvious to those skilled in the art from the foregoing detailed description of the invention. It is intended that all of these variations and modifications be included within the scope of this invention.

COMS ID No: SMBI-00483657 Received by IP Australia: Time 16:01 Date 2003-11-06 q Throughout this specification the word "comprise", or variations such as "comprises" or '"comprising", will be understood to imply the inclusion of a stated element, integer or step, 00 or group of elements, integers or steps, but not to the exclusion of any other element, integer or step, or group of elements, integers or steps.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without Nq departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

All publications mentioned in this specification are herein incorporated by reference. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of the application.

201022819 1

Claims (71)

1. A method for the treatment of HIV infection in a host comprising administering an effective amount of P-L-(2'-azido)-2',3'-dideoxy-5-fluorocytidine compound or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula: NHR N N^ O.0- F RO RO F N 3 NHR' wherein R is H, acyl, monophosphate, diphosphate, or triphosphate, or a stablized phosphate derivative (to form a stablized nucleotide prodrug), and R' is H, acyl, or alkyl; in a pharmaceutically acceptable carrier.

2. The method of claim 1, wherein R is H.

3. The method of claim 1, wherein R is acyl.

4. The method of claim 1, wherein R is monophosphate The method of claim 1, wherein R is disphosphate

6. The method of claim 1, wherein R is triphosphate

7. The method of claim 1, wherein R is a stablized phosphate derivative.

8. A method for the treatment of HIV infection in a host comprising administering an effective amount of 3-L-(3'-azido)-2',3'-dideoxy-5-fluorocytidine compound or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula: 201022819_1 IO O oNHR' 00 N 0 N RO N 3 NHR' wherein R is H, acyl, monophosphate, diphosphate, or triphosphate, or a stablized phosphate derivative (to form a stablized nucleotide prodrug), R' is H, acyl, or alkyl; in a pharmaceutically acceptable carrier.

9. The method of claim 8, wherein R is H.

10. The method of claim 8, wherein R is acyl.

11. The method of claim 8, wherein R is monophosphate.

12. The method of claim 8, wherein R is diphosphate.

13. The method of claim 8, wherein R is triphosphate.

14. The method of claim 8, wherein R is a stablized phosphate derivative.

15. The method of any one of claims 1-14, wherein the pharmaceutically acceptable carrier is suitable for oral delivery.

16. The method of any one of claims 1-14, wherein the pharmaceutically acceptable carrier is suitable for intravenous delivery.

17. The method of any one of claims 1-14, wherein the pharmaceutically acceptable carrier is suitable for parenteral delivery.

18. The method of any one of claims 1-14, wherein the pharmaceutically acceptable carrier is suitable for intradermal delivery.

19. The method of any one of claims 1-14, wherein the pharmaceutically acceptable carrier is suitable for subcutaneous delivery. 201022819_1 IO O The method of any one claims 1-14, wherein the pharmaceutically acceptable carrier is suitable for topical delivery. 00 21. The method of any one claims 1-14, wherein the compound is in the form of a dosage unit. in 5 22. The method of claim 21, wherein the dosage unit is a tablet or capsule. r- S23. The method of claim 21, wherein the dosage unit contains 10 to 1500 mg of the N compound. O 24. The method of claim 23, wherein the dosage unit is a tablet or capsule. A method for the treatment of HIV infection in a host comprising administering an effective amount of a -L-(2'-azido)-2',3'-dideoxy-5-fluorocytidine compound or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula: NHR' 0 R RO 0 N RON O I 0 N 'N J o N 3 NHR' wherein R is H, acyl, monophosphate, diphosphate, or triphosphate, or a stablized phosphate derivative (to form a stablized nucleotide prodrug), R' is H, acyl, or alkyl; in combination or alternation with another effective anti-HIV agent, optionally in a pharmaceutically acceptable carrier.

26. The method of claim 25, wherein R is H.

27. The method of claim 25, wherein R is acyl.

28. The method of claim 25, wherein R is monophosphate.

29. The method of claim 25, wherein R is diphosphate. The method of claim 25, wherein R is triphosphate.

31. The method of claim 25, wherein R is a stabilized phoshate derivate. 201022819_1 \O

32. The method of the treatment of HIV infection in a host comprising administering an effective amount of a -L-(3'-azido)-2',3'-dideoxy-5-fluorocytidine compound or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula: 00 NHR' RO 0O N FF \OO c mooo I N 3 NHR' wherein R is H, acyl, monophosphate, diphosphate, or triphosphate, or a stablized phosphate derivative (to form a stablized nucleotide prodrug), R' is H, acyl, or alkyl; in combination or alternation with another effective anti-HIV agent.

33. The method of claim 32, wherein R is H.

34. The method of claim 32, wherein R is acyl. The method of claim 32, wherein R is monophosphate.

36. The method of claim 32, wherein R is diphosphate.

37. The method of claim 32, wherein R is triphosphate.

38. The method of claim 32, wherein R is a stabilized phosphate derivate.

39. The method of any one of claims 25-38 wherein the other anti-HIV agent is selected from the group consisting of 2-hydroxymethyl-5-(5-fluorocytosin-I yl)-1,3- oxathiolane (FTC); carbovir, acyclovir, interferon, AZT, DDI, DDC, D4T, CS-92, (3'-azido-2'3'dideoxy-5-methyl-cytidine), P-D-dioxolany-guanine (DXG), P-D- dioxolanyl-2,6-diaminopurine (DAPD), P-D-dioxolanyl-6 chloropurine (ACP), MKC-442, (6-benzyl- -(ethoxymethyl)-5 isopropyl uracil; crixovan, nelfinavir, ritonavir, saquinavir and DMP-450. 201022819 I IO

40. The method of claim 39 wherein the other anti-HIV is 2-hydroxymethyl-5-(5- fluorocytosin- -yl)-1,3 oxathiolane (FTC). oO 41. The method of claim 39 wherein the other anti-HIV agent is AZT.

42. The method of claim 39, wherein the other anti-HIV agent is p-D-dioxolanyl- in 5 guanine (DXG). S43. The method of claim 39 wherein the other anti-HIV agent is -D-dioxolanyl-2,6- diaminopurine (DAPD). S44. The method of claim 39 wherein the other anti-HIV agent is ritonavir. O1 The method of claim 39 wherein the other anti-HIV agent is saquinavir.

46. The method of any one of claims 25-45, further comprising a pharmaceutically acceptable carrier.

47. The method of claim 46, wherein the pharmaceutically acceptable carrier is suitable for oral delivery.

48. The method of claim 46, wherein the pharmaceutically acceptable carrier is suitable for intravenous delivery.

49. The method of claim 46, wherein the pharmaceutically acceptable carrier is suitable for parenteral delivery. The method of claim 46, wherein the pharmaceutically acceptable carrier is suitable for intrademal delivery.

51. The method of claim 46, wherein the pharmaceutically acceptable carrier is suitable for subcutaneous delivery.

52. The method of claim 46, wherein the pharmaceutically acceptable carrier is suitable for topical delivery.

53. The method of claim 46, wherein the compound is in the form of a dosage unit.

54. The method of claim 53, wherein the dosage unit is a table or capsule. The method of claim 53, wherein the dosage unit contains 10 to 1500mg of the compound.

56. The method of claim 55, wherein the dosage unit is a tablet or capsule. 201022819 1 IO 0O c, t(N

57. A method for the treatment of HIV infection in a human comprising administering an effective amount of a P-L(2'-azido)-2',3'-dideoxy 5-fluorocytidine compound or a pharmaceutically acceptable ester, salt or prodrug therof of the formula: NHR' N 3 N RO N SRORN N N NF N 3 NHR' wherein R is H, acyl, monophosphate, diphosphate, or triphosphate, or a stabilized phosphate derivative (to form a stabilized nucleotide prodrug), and R' is H, acyl, or alkyl.

58. The method of claim 57, wherein R is H.

59. The method of claim 57, wherein R is acyl. The method of claim 57, wherein R is monophosphate.

61. The method of claim 57, wherein R is diphosphate.

62. The method of claim 57, wherein R is triphosphate.

63. The method of claim 57, wherein R is a stabilized phosphate derivative.

64. A method for the treatment of HIV infection in a human comprising administering an effective amount of P-L-(3'-azido)-2,3' dideoxy-5-fluorocytidine compound or a pharmaceutically acceptable ester, salt or prodrug thereof of the formula: 201022819_1 O IND 00 RO N NF F o N 3 NHR' wherein R is H, acyl, monophosphate, diphosphate, or triphosphate, or a stabilized phosphate derivative (to form a stabilized nucleotide prodrug), R' is H, acyl, or alkyl. The method of claim 64, wherein R is H.

66. The method of claim 64, wherein R is acyl.

71. The method of any one of claims 57 70, further comprising a pharmaceutically acceptable carrier.

72. The method of claim 71, wherein the pharmaceutically acceptable carrier is suitable for oral delivery.

73. The method of claim 71, wherein the pharmaceutically acceptable carrier is suitable for intravenous delivery.

74. The method of claim 71, wherein the pharmaceutically acceptable carrier is suitable for parental delivery. The method of claim 71, wherein the pharmaceutically acceptable carrier is suitable for intradermal delivery.

76. The method of claim 71, wherein the pharmaceutically acceptable carrier is suitable for subcutaneous delivery. 201022819_1 \O

77. The method of claim 71, wherein the pharmaceutically acceptable carrier is suitable e( for topical delivery. 00 78. The method of claim 71, wherein the compound is in the form of a dosage unit.

79. The method of claim 78, wherein the dosage unit is a tablet or capsule. S 5 80. The method of claim 78, wherein the dosage unit contains 10 to 1500 mg of the _compound. N 81. The method of claim 80, wherein the dosage unit is a tablet or capsule.

82. The method of claim 1, wherein the compound is a pharmaceutically acceptable ester.

83. The method of claim 1, wherein the compound is a pharmaceutically acceptable salt.

84. The method of claim 1, wherein the compound is a pharmaceutically acceptable stabilized phosphate derivative to form a stabilized nucleotide prodrug. The method of claim 8, wherein the compound is a pharmaceutically acceptable ester.

86. The method of claim 8, wherein the compound is a pharmaceutically acceptable salt.

87. The method of claim 8, wherein the compound is a pharmaceutically acceptable stabilized phosphate derivative to form a stabilized nucleotide prodrug.

88. The method of claim 25, wherein the compound is a pharmaceutically acceptable ester.

89. The method of claim 25, wherein the compound is a pharmaceutically acceptable salt. The method of claim 25, wherein the compound is a pharmaceutically acceptable stabilized phosphate derivative to form a stabilized nucleotide prodrug.

91. The method of claim 32, wherein the compound is a pharmaceutically acceptable ester.

92. The method of claim 32, wherein the compound is a pharmaceutically acceptable salt. 201022819 1 \O

93. The method of claim 32, wherein the compound is a pharmaceutically acceptable 0. stabilized phosphate derivative to form a stabilized nucleotide prodrug.

94. The method of claim 57, wherein the compound is a pharmaceutically acceptable 00 C ester.

95. The method of claim 57, wherein the compound is a pharmaceutically acceptable salt. ko 96. The method of claim 57, wherein the compound is a pharmaceutically acceptable r n stabilized phosphate derivative to form a stabilized nucleotide prodrug. Ni 97. The method of claim 64, wherein the compound is a pharmaceutically acceptable ester.

98. The method of claim 64, wherein the compound is a pharmaceutically acceptable salt.

99. The method of claim 64, wherein the compound is a pharmaceutically acceptable stabilized phosphate derivative to form a stabilized nucleotide prodrug.

100. The method of any one of claims 1, 8, 25, 32, 57 or 64, wherein the host is a human. 201022819_1