Although many pharmaceutical compounds and compositions are available for the treatment of viral infections, there remains a continuing need for improved treatments.

The present inventors have discovered a new class of chemical compounds which are particularly useful in the treatment of viral infection.

According to the present invention there is provided a compound of the formula wherein X is selected from O, S, SO, SO2, NR, CR2, C (OH) R and C=O each Rl is independently selected from H, CI-12 alkyl and C3-12 aryl, R is selected from H, C1-12 alkyl and C3-12 aryl, R3 is selected C1-12 alkyl, C1-12 alkoxy, C1-12 alkanoyl, C3-12 aryl, C3-12 aryloxy and C3-12 aryloyl, yl and y2 are independently selected from Cl-12 alkylene, C4-12 arylene, C4-16 aralkylene, CO (CI-l2 alkylene), CO (C4-12 arylene) and CO (C4-16 aralkylene) groups, A and B are independently selected from groups comprising a group selected from: amine (-NR2), amide (-CONR2), amidine (-C (=NR) NR2), thioamide (-CSNR2), oxime (=NOR), hydroxylamine (-NHOR), hydroxamic acid (-CONROR), hydrazine (-NRNR2), hydrazone (=NNR2), sulphonamide (-SO2NR2), sulphinamide (-SONR2), sulphoximine (-SO (=NR)-), urea

(-NRCONR2), guanidine (-NRC (=NR) NR2), and aromatic and non-aromatic nitrogen heterocyclic groups, each R is independently selected from H, C1-12 alkyl or C3-12 aryl, or any two R groups may together comprise a C1-6 alkylene chain, and pharmaceutically acceptable derivatives thereof.

X may be O, S, SO, SO2, NR, CR2 C (OH) R or C=O. Preferably, X is O.

Each Rl is independently selected from H, C1-12 alkyl and C3-12 aryl. Preferably both Ri are H.

R2 is selected from H, C1-l2 alkyl and C3-12 aryl. Preferably R2 is selected from H and CI-12 alkyl. More preferably R2 is H.

R3 is selected from Cl-12 alkyl, C1-12 alkoxy, C1-12 alkanoyl, C3-12 aryl, C3-12 aryloxy and C3-12 aryloyl. Preferably R3 is C3-12 aryl.

When R3 is aryl, the aryl group is preferably a monocyclic or fused polycyclic (preferably bicyclic such as [6,5], [6,6] and [5,5] systems) aromatic or heteroaromatic group. Aromatic groups include phenyl and naphthyl. Heteroaromatic groups are generally preferred to the corresponding aromatic group. Heteroaromatic groups may comprise one or more heteroatoms. Monocyclic heteroaromatic groups include pyridyl, pyrrolyl, furanyl and thienyl. Heteroaromatic groups may be bonded to the rest of the molecule either via a ring carbon atom or via a ring heteroatom. Preferred fused bicyclic heteroaromatic groups include [6,5] (such as indolyl, benzofuranyl, benzothienyl), [6,6] (such as quinolinyl, isoquinolinyl, quinoxalinyl) and [5,5] fused bicyclic heteroaromatic groups. [6,5] ring systems, in which a heteroatom may be located at any ring position, are preferred. Particularly preferred fused bicyclic heteroaromatic groups comprise groups of the structure :

wherein X2 is NH, S or O. Indoles (i. e. where X2 is NH) are preferred.

Bicyclic heteroaromatic groups of this structure may be bonded to the rest of the molecule via any position, bonding via the 2,3,5 or 6 position being preferred.

The group R3 may be substituted as herein defined.

Il and Y2 are independently selected from Cl-l2 alkylene, C4-12 arylene, C4-16 aralkylene, CO (C1-12 alkylene), CO (C4-12 arylene) and CO (C4-16 aralkylene) groups, as herein defined.

Preferably, Y'comprises a direct chain of 1 to 5 carbon atoms linking the O atom of the side chain and A. For example, if yl is an ethylene or o-phenylene group, the direct chain linking the O atom and A has two carbon atoms. Preferably, Y'comprises a C1-5 alkylene group.

Preferably, y2 comprises a direct chain of 1 to 5 carbon atoms linking the N atom of the side chain and B. Preferably, y2 comprises a Ci-5 alkylene group.

A and B are independently selected from groups comprising a group selected from amine (-NR2), amide (-CONR2), amidine (-C (=NR) NR2), thioamide (-CSNR2), oxime (=NOR), hydroxylamine (-NHOR), hydroxamic acid (-CONROR), hydrazine (-NRNR2), hydrazone (=NNR2), sulphonamide (-SO2NR2), sulphinamide (-SONR2), sulphoximine (-SO (=NR)-), urea (-NRCONR2), guanidine (-NRC (=NR) NR2), and aromatic and non-aromatic nitrogen heterocyclic groups.

Preferably, A and B are independently selected from groups comprising a group selected from amine, amidine, guanidine, and aromatic and non-aromatic nitrogen heterocyclic groups. Preferably, the amine, amidine and guanidine groups are unsubstituted (i. e. R=H).

The aromatic and non-aromatic nitrogen heterocyclic groups may be monocyclic (preferably 5 or 6 membered rings) or polycyclic (preferably fused bicyclic, more preferably [6,5], [6,6] and [5,5] systems) and may comprise one or more nitrogen atom. Examples of aromatic nitrogen heterocyclic groups include pyrrolyl, pyridinyl, 2-, 3- and 4-pyrimidinyl, quinolinyl, isoquinolinyl, indolinyl, benzodiazolyl, benzotriazolyl, imidazolyl, triazolyl and thiazolyl groups. Examples of non-aromatic nitrogen heterocyclic groups include pyrrolidinyl, piperidinyl, morpholinyl and piperazinyl groups. The aromatic and non-aromatic nitrogen heterocyclic groups may be substituted or unsubstituted. Preferred substituents include amino groups (-NR2). The aromatic and non- aromatic nitrogen heterocyclic group may be bonded to the rest of the molecule via a ring carbon atom or via a ring nitrogen atom or via a substituent.

Included within the scope of the term aromatic and non-aromatic nitrogen heterocyclic groups are cyclic groups which mimic amidine or guanidine groups of the general formulae Specific examples include 2-aminopyridine, 2-aminopyrimidine and 2-pyrimidine groups: Each R is independently selected from H and C 1-6 alkyl, or any two R groups may together

comprise a C2-6 alkylene chain.

As used herein, the term"alkyl"means a branched or unbranched, cyclic or acyclic, saturated or unsaturated (e. g. alkenyl or alkynyl) hydrocarbyl radical. Where acyclic, the alkyl group is preferably a Cl l2, more preferably Cl 4 chain. Where cyclic, the alkyl group is preferably a C3 l2, more preferably C5-10 and more preferably comprises a C5, C6 or C7 ring. The alkyl chain or ring may include (i. e. be optionally interrupted with and/or terminate with) one or more heteroatoms, such as oxygen, sulphur or nitrogen.

As used herein the term"alkylene"means a branched or unbranched, cyclic or acylic, saturated or unsaturated divalent hydrocarbyl radical. Where acyclic the alkylene group is preferably a C1-12, more preferably C1-5 chain. Where cyclic, the alkylene group is preferably a C3-12, more preferably a Cs-io, more preferably a C5, C6 or C7 ring. The alkylene chain or ring may include (i. e. be interrupted and/or terminate with) one or more heteroatoms such as oxygen, sulfur or nitrogen.

As used herein, the term"aryl"means a C3-26, preferably C3-12, aromatic group, such as phenyl or naphthyl, or a heteroaromatic group containing one or more, preferably one, heteroatom, such as pyridyl, pyrrolyl, furanyl, thienyl.

As used herein the term"arylene"means a divalent hydrocarbyl radical comprising a C3-12 aromatic group (such as o-, m-orp-phenylene) or heteroaromatic group containing one or more, preferably one, heteroatom (such as a pyridine-2,3-diyl group).

As used herein the term"aralkylene"means a divalent hydrocarbyl radical comprising both alkylene and arylene groups (such as-CH2- (o-phenylene)-CH2-).

The alkyl, aryl, alkylene, arylene and aralkylene groups may be further substituted or unsubstituted. Where substituted, there are preferably one to three substituents, more preferably one substituent. For example, a Cl (methyl) group may be further substituted with a phenyl group to give a benzyl group. Substituents may include carbon containing groups such as CI-5 alkyl, C3-12 aryl, C3-16 aralkyl (e. g. substituted and unsubstituted phenyl,

substituted and unsubstituted benzyl); halogen atoms and halogen containing groups such as haloalkyl (e. g. trifluoromethyl); oxygen containing groups such as alcohols (e. g. hydroxy, hydroxyalkyl, aryl (hydroxy) alkyl), ethers (e. g. alkoxy, alkoxyalkyl, aryloxyalkyl), aldehydes (e. g. carboxaldehyde), ketones (e. g. alkylcarbonyl, alkylcarbonylalkyl, arylcarbonyl, arylalkylcarbonyl, arylcarbonylalkyl), acids (e. g. carboxy, carboxyalkyl), acid derivatives such as esters (e. g. alkoxycarbonyl, alkoxycarbonylalkyl, allcycarbonylyoxy, allcycarbonylyoxyalkyl) and amides (e. g. aminocarbonyl, mono-or dialkylaminocarbonyl, aminocarbonylalkyl, mono-or diallcylaminocarbonylalkyl, arylaminocarbonyl); and carbamates (e. g. alkoxycarbonylamino, aryloxycarbonylamino, aminocarbonyloxy, mono-or dialkylaminocarbonyloxy, arylaminocarbonyloxy), and ureas (e. g. mono-or dialkylaminocarbonylamino or arylaminocarbonylamino) ; nitrogen containing groups such as amines (e. g. amino, mono-or dialkylamino, aminoalkyl, mono-or dialkylaminoalkyl), azides, nitriles (e. g. cyano, cyanoalkyl), nitro; sulfur containing groups such as thiols, thioethers, sulfoxides, and sulfones (e. g. alkylthio, alkylsulfinyl, alkylsulfonyl, alkylthioalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, arylthio, arylsulfmyl, arylsulfonyl, arylthioalkyl, arylsulfinylalkyl, arylsulfonylalkyl) ; and heterocyclic groups containing one or more, preferably one, heteroatom (e. g. thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, oxadiazolyl, thiadiazolyl, pyrrolidinyl, pyrrolinyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, tetrahydrofuranyl, pyranyl, pyronyl, pyridyl, pyrazinyl, pyridazinyl, piperidyl, piperazinyl, morpholinyl, thianaphthyl, benzofuranyl, isobenzofuranyl, indolyl, oxyindolyl, isoindolyl, indazolyl, indolinyl, 7-azaindolyl, benzopyranyl, coumarinyl, isocoumarinyl, quinolinyl, isoquinolinyl, naphthridinyl, cinnolinyl, quinazolinyl, pyridopyridyl, benzoxazinyl, quinoxalinyl, chromenyl, chromanyl, isochromanyl, phthalazinyl and carbolinyl).

As used herein, the term"alkoxy"means alkyl-O-and"alkanoyl"means alkyl-CO. Alkyl substituent groups or alkyl-containing substituent groups may comprise one or more further substituents. As used herein, the term"aryloxy"means aryl-0-and"aryloyl" means aryl-CO. Aryl substituent groups or aryl-containing substituent groups may comprise one or more further substituents.

As used herein, the term"halogen"means a fluorine, chlorine, bromine or iodine radical, preferably a fluorine or chlorine radical.

By"a pharmaceutically acceptable derivative"is meant any pharmaceutically acceptable salt, addition compound, or any other compound which upon administration to a recipient is capable of providing (directly or indirectly) a compound of the present invention or a pharmaceutically acceptable metabolite. By"pharmaceutically acceptable metabolite"is meant a metabolite or residue of a compound of the present invention which gives rise to a biological activity exhibited by the present compounds.

As used herein, a"patient"is a mammal (e. g., such as a human being or other non-human mammal) to whom a compound according to the invention is administered. The term "patient"does not imply that the individual has ever been hospitalized for medical treatment.

As used herein,"anti-viral properties"refer to the ability of the compounds according to the invention to inhibit viral growth. As defined herein,"inhibiting growth"includes reference to an inhibition in the translation of proteins, which in turn results in an inhibition in replication (and therefore transcription of mRNAs) which in turn results in an inhibition of infection. Any one of these processes (e. g., translation, replication, transcription, infection) may be assayed to determine the effectiveness of the compounds according to the invention (e. g., defined as the ability of the compound to inhibit growth).

As defined herein,"inhibition of growth"refers to an at least two-fold decrease in any of the parameters discussed above (e. g., translation of proteins, replication of microorganisms, transcription of mRNAs, and/or infection by microorganisms). Inhibition can also refer to an at least two fold decrease in an immune response associated with a infection (e. g., such as the accumulation of antibodies or cytokines and/or pyrogens associated with infection). In one embodiment, inhibition is at least 2-fold, at least 10-fold, at least 20-fold, at least 30-fold, at least 40-fold, at least 50-fold, or at least 100-fold.

In a preferred embodiment of the invention, the compound inhibits translation of a viral transcript. In still a more preferred embodiment, the compound inhibits translation of a viral transcript while not inhibiting translation of a mammalian transcript. In one

embodiment of the invention, translation is inhibited at least 2-fold, at least 5-fold, at least 10-fold, at least 20-fold, at least 30-fold, at least 40-fold, at least 50-fold, or at least 100- fold compared to translation of viral transcripts in a mammalian organism which has not been treated with the compounds according to the invention. In a further embodiment, the compound inhibits viral replication.

According to a further aspect of the present invention there is provided a compound according to the present invention for use in a method of treatment, preferably in the prophylaxis or treatment of viral infection.

According to a further aspect of the present invention there is provided use of a compound according to the present invention in the manufacture of a medicament for the prophylaxis or treatment of viral infection.

According to a further aspect of the present invention there is provided a method of prophylaxis or treatment of viral infection comprising administration to a patient in need of such treatment an effective dose of a compound according to the present invention. Treatment or prophylaxis according to the invention is indicated by the amelioration or lessening of symptoms or clinical parameters associated with the viral infection, as judged by the physician for one or more of those symptoms or clinical parameters clincally associated with the viral infection. Animal models of viral infections are well-lçnown in the art for many viral infections.

In one embodiment, the effective dose of the compound according to the invention is a dose effective to decrease the titer of infectious microorganisms in a patient's body. In one embodiment, the titer of infectious microorganisms is measured by culturing a bodily sample and counting the number of microorganisms in the sample. In another embodiment, the titer of infectious microorganisms is determined by measuring the expression of viral nucleic acids and/or proteins. In a further embodiment, the effective dose of the compound is a dose effective to restore the immune response of a host (e. g., a patient) to a microorganism to normal (e. g., to resemble an immune response of an

uninfected host). For example, in one embodiment, a bodily fluid from a patient is assayed to detect the presence and/or amounts of or antiviral antibodies.

In one embodiment, the patient treated has AIDS. In another embodiment, the person has AIDS and at least one opportunistic infection.

In another embodiment, a compound according to the invention is used prophylactically.

In one embodiment, the compound is contacted with a cell or surface thereby to prevent the growth of microorganisms in proximity to the cell or surface. In one embodiment, the compound is administered to a patient to prevent infection by a microorganism or to reduce the severity of infection (e. g., as measured by determining the titer of the microorganism in a treated vs. an untreated individual).

Viral infections include Family Virus Disease Adenoviruses Adenovirus acute respiratory disease Arenaviruses Lassa Virus Lassa Fever Astroviridae Astrovirus Enteritis Bunyaviridae Hantavirus Hantavirus Pulmonary Syndrome Phlebovirus Rift Valley Fever Calciviridae Hepatitis E Filoviridae Ebola Virus Marburg Virus Flaviviridae Japanese Encephalitis Virus Hepatitis C Virus Dengue Virus Dengue Haemorrhagic Fever Yellow Fever Virus Hepatitis G Virus Hepadnaviridae Hepatitis B Virus Hepatitis D (delta) Virus Herpesviridae Herpes Simplex Virus 1 Herpes Simplex Virus 2 Cytomegalovirus (CMV) Epstein Barr Virus (EBV) Mononucleosis Varicello Zoster Virus (VZV) Chicken Pox/Shingles HHV-6 HHV-7 KSHV/HHV8 Kaposi Sarcoma

Orthomyxoviruses Influenza Virus Paramyxoviridae Paramyxoviruses Para-Influenza Rubulaviruses Mumps Morbilliviruses Measles Respiratory Syncytial Virus Papovaviridae Papillomaviruses Warts/Cervical Cancer Polyomaviruses BK and JC Virus Parvoviridae Parvoviruses Erythema Infectiosum Picornaviridae Coxsackie Viruses (A and B) Viral Myocarditis & Meningitis & Enteritis Hepatitis A Virus Hepatitis Polioviruses Poliomyelitis Rhinoviruses Cold Reoviridae Astroviruses Diarrhoea Caliciviruses Diarrhoea Reoviruses Diarrhoea Rhabdoviridae Lyssavirus Rabies Retroviridae HIV-1 and HIV-2 AIDS HTLV-1 and HTLV-2 Leukaemia Preferably, the viral infection comprises HIV or HCV infection, more preferably HIV-I or HIV-II.

It is a feature of the compounds of the present invention that they inhibit the binding of viral and/or cellular substances needed for viral growth to RNA. Without being bound to any one mechanism of action, it is believed that the inventive compounds are effective in viral infection by inhibiting such binding. For example, the compounds of the present invention inhibit the binding of the HIV protein Tat to the HIV RNA Tar binding site.

Accordingly, the present invention further provides use of a compound of the present invention to inhibit the binding of a compound, preferably a protein, to RNA. More particularly, the present invention further provides use of a compound of the present invention to inhibit the binding of Tat to Tar. Inhibition of binding refers to wherein the compound prevents association of the substance with the RNA at a concentration of preferably less than 1 Ki (uM), and, more preferably less than 10 Ki, even more preferably less than 50 Ki.

According to a further aspect of the present invention there is provided a pharmaceutical composition comprising a compound of the present invention in combination with a pharmaceutically acceptable excipient.

According to a further aspect of the present invention there is provided a method of preparing a pharmaceutical composition comprising the step of combining a compound of the present invention with a pharmaceutically acceptable excipient.

According to a further aspect of the present invention there is provided a process for the preparation of the compounds of the present invention. The compounds may be prepared according to the following general reaction scheme.

General Reaction Scheme

Reagents (i) Rlhalide, Cs2CO3 ; (ii) R2halide, Cs2CO3 ; (iii) NaOMe, MeOH ; (iv) R2YH, Pd catalyst; (v) ArB (OH) 2, CO (g), Pd catalyst; (vi) R4R5NH, DCE or EtOH, reducing agent; (vii) oxidizing agent; (viii) NaBH4, solvent, (ix) (a) H2, Pd/C, solvent or (b) Et3SiH, solvent.

The compounds according to the invention have anti-microbial (e. g., anti-viral properties). In one embodiment, the compounds inhibit microbial growth. Inhibition of microbial growth can be assayed in a number of different ways. In one embodiment, microbial

growth is measured by assaying the translation of microbial proteins, levels of microbial replication, transcription of microbial mRNAs, and infectivity (e. g., viral titer in cells exposed to a virus). Assays for measuring such parameters are well known in the art and include, but are not limited to, immunossays to detect translation products or assays which measure binding of translational regulators to mRNA transcripts (e. g., to measure translation), RT-PCT, or hybridization assays (e. g., to measure transcription), incorporation of labeled nucleotides or hybridization assays to measure the presence/amount of microbial genomic DNA (e. g., to measure replication), plate counting assays (e. g., to measure microbial titers), and the like.

In one embodiment, compounds are synthesized according to the methods described above and the ability of the compounds to inhibition of microbial growth is assayed to identify compounds which produce an at least two-fold decrease in any of the parameters discussed above (e. g., translation of microbial proteins, replication of microorganisms, transcription of microbial mRNAs, and/or infection by microorganisms). In one embodiment, inhibition is at least 2-fold, at least 10-fold, at least 20-fold, at least 30-fold, at least 40-fold, at least 50-fold, or at least 100-fold. In one embodiment, activity is measured in vitro, e. g., by measuring the effects of the compounds on cells infected or to be infected with a virus. In another embodiment, compounds are selected which inhibit the growth of viral microorganisms. In one embodiment, compounds are selected which inhibit the growth of HIV in cells infected or to be infected with the virus. In still another embodiment, compounds are selected which inhibit the growth of HIV and any of the characteristic microorganisms found in opportunistically infected AIDS patients.

In another embodiment, compounds according to the invention are tested in animal models to determine the effects of the compounds on microbial growth as described above. In one embodiment, the compounds are tested for their affect on the immune response of an animal to a microbial infection to select compounds which return the immune response to normal (e. g., provide a response similar to that observed in an animal which has not been infected. For example, in one embodiment, a bodily fluid (e. g., blood) is obtained from an infected animal at various time points after administering a compound according to the invention to determine the presence or absence of antibodies specific for microbial

antigens and/or the presence or absence of cytokines characteristic of microbial infection.

Additionally, or alternatively, the animal may be tested by evaluating any of the parameters discussed above (e. g., translation of microbial proteins, replication of microorganisms, transcription of microbial mRNAs, and/or infection by microorganisms).

In a preferred embodiment, the compounds according to the invention inhibit translation of a viral transcript. In still a more preferred embodiment, the compound inhibits translation of a viral transcript while not inhibiting translation of a mammalian transcript. In one embodiment of the invention, translation is inhibited at least 2-fold, at least 5-fold, at least 10-fold, at least 20-fold, at least 30-fold, at least 40-fold, at least 50-fold, or at least 100- fold compared to translation of viral transcripts in a mammalian organism which has not been treated with the compounds according to the invention. In one embodiment, a reporter gene is cloned downstream and in frame with a viral translation initiation sequence, and the activity of the compounds synthesised is assayed by monitoring the presence and/or amount of the protein encoded by the reporter gene.

In a preferred embodiment, a compound according to the invention is provided which inhibits the binding of the HIV protein Tat to the HIV RNA Tar binding site. Accordingly, the present invention further provides use of a compound of the present invention to inhibit the binding of Tat to Tar. In one embodiment, inhibition is measured directly by measuring binding of Tat to Tar. In another embodiment, inhibition is measured by measuring the production of Tat protein.

In another embodiment, the compounds according to the invention are tested for their ability to prevent microbial infection. For example, in one embodiment, the compounds are contacted to a cell and the ability of a microorganism to grow in proximity to said cell is evaluated. In one embodiment, the cell is a cell which is to be infected with a virus, and the cell is contacted with the compound prior to contacting the cell with the virus. The ability of the compounds to be used prophylactically is then evaluated as described above (e. g., by assaying one or more of translation of microbial proteins, replication of microorganisms, transcription of microbial mRNAs, and/orinfection by microorganisms).

In a further embodiment, the compounds according to the invention are contacted with a surface and assayed for their ability to prevent microbial growth on the surface.

The medicament employed in the present invention can be administered by oral or parenteral routes, including intravenous, intramuscular, intraperitoneal, subcutaneous, transdermal, airway (aerosol), rectal, vaginal and topical (including buccal and sublingual) administration.

For oral administration, the compounds of the invention will generally be provided in the form of tablets or capsules, as a powder or granules, or as an aqueous solution or suspension.

Tablets for oral use may include the active ingredients mixed with pharmaceutically acceptable excipients such as inert diluents, disintegrating agents, binding agents, lubricating agents, sweetening agents, flavouring agents, colouring agents and preservatives. Suitable inert diluents include sodium and calcium carbonate, sodium and calcium phosphate, and lactose, while corn starch and alginic acid are suitable disintegrating agents. Binding agents may include starch and gelatin, while the lubricating agent, if present, will generally be magnesium stearate, stearic acid or talc. If desired, the tablets may be coated with a material such as glyceryl monostearate or glyceryl distearate, to delay absorption in the gastrointestinal tract.

Capsules for oral use include hard gelatin capsules in which the active ingredient is mixed with a solid diluent, and soft gelatin capsules wherein the active ingredients is mixed with water or an oil such as peanut oil, liquid paraffin or olive oil.

Formulations for rectal administration may be presented as a suppository with a suitable base comprising for example cocoa butter or a salicylate.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such carriers as are known in the art to be appropriate.

For intramuscular, intraperitoneal, subcutaneous and intravenous use, the compounds of the invention will generally be provided in sterile aqueous solutions or suspensions,

buffered to an appropriate pH and isotonicity. Suitable aqueous vehicles include Ringer's solution and isotonic sodium chloride. Aqueous suspensions according to the invention may include suspending agents such as cellulose derivatives, sodium alginate, polyvinyl- pyrrolidone and gum tragacanth, and a wetting agent such as lecithin. Suitable preservatives for aqueous suspensions include ethyl and n-propyl p-hydroxybenzoate.

The compounds of the invention may also be presented as liposome formulations.

In general a suitable dose will be in the range of 0.01 to 100 mg per kilogram body weight of the recipient per day, preferably in the range of 0.2 to 10 mg per kilogram body weight per day. The desired dose is preferably presented once daily, but may be dosed as two, three, four, five or six or more sub-doses administered at appropriate intervals throughout the day. These sub-doses may be administered in unit dosage forms, for example, containing 10 to 1500 mg, preferably 20 to 1000 mg, and most preferably 50 to 700 mg of active ingredient per unit dosage form. In a preferred method according to the present invention, the compounds are used to prevent or delay the onset of HIV-infection in individuals who are susceptible or at risk of HIV-infection (e. g., intravenous drug users, patients who have had, or are about to receive, a blood transfusion, immunodeficient or immunocompromised patients, gay men, and the like) The method comprises administering to such a patient a prophylactically effective amount (which generally is the same as a therapeutically effective amount) of one or more of the compositions according to the present invention to the patient to delay or prevent an HIV-infection. In another embodiment of the invention, the compounds are used to treat an already-infected patient (e. g., an HIV-positive patient) to prevent re-infection and to inhibit viral replication and/or further infection by opportunistic microorganisms. The compounds may be used by themselves or in conjunction with other drugs (e. g., protease inhibitors, antibiotics) or other therapies.

The invention will now be described with reference to the following Examples. It will be appreciated that what follows is by way of example only and that modifications to detail may be made whilst still falling within the scope of the invention.

EXPERIMENTAL Chemical Synthesis The following general techniques were employed.

Reverse Phase Preparative HPLC Method HPLC: Gilson 306 Column: 100 x 21. 2 mm 5 Hypersil (g) Elite C18 Temperature: Room temperature Solvents: A-Acetonitrile B-H20 + 0.2% TFA Flow rate: 30mL/min Gradient: Total time 9 minutes -5% A and 95% B at start -ramp up to 95% A and 5% B over 6 minutes -95% A and 5% B for 3 minutes Detection: UV detection at 230nm, 254nm or 280nm Analytical HPLC Method Examples 19-24 HPLC: Waters 600E Column: 150 x 4.6 mm 5µ Hypersil# Elite C18 Temperature: Room temperature Solvents: A-Acetonitrile B-H20 + 0. 2% TFA Flow rate: 1. 5mL/min (isocratic) Flow rate: 3 mL/min (gradient) Gradient: Total time 9 minutes -5% A and 95% B at start

-ramp up to 95% A and 5% B over 3.5 minutes -95% A and 5% B for 2.5 minutes Detection: W detection at 230nm, 254nm or 280nm Mass Spectrometry Method Examples 19-24 Mass spec: Micromass Platform LC Method: Electrospray, +'ve ion and-'ve ion LCMS Method Examples 1-18 HPLC : HP 1100 Column: ABZ+, 3.3cm*4.6mmD Temperature: 20°C Solvents: A-Water + 0. 1 % formic acid + 1 Ommol ammonium acetate B-95% Acetonitrile/water + 0.05% formic acid Flow rate: 1mL/min Gradient: Total time 8 minutes -100% A for 0.7 minutes -ramp up to 100% B over 3. 5 minutes -100% B for 3.5 minutes -ramp down to 0% B over 0.3 minutes Detection: UV detection at 230nm, 254nm and 270nm Mass spec : HP1100 MSD Method: Electrospray, +'ve ion

Reagents: (i) Br (CH2) mCH2NHBoc, Cs2CO3, DMF; (ii) BocNH (CH2)nCH2NH2, DCE, sodium triacetoxyborohydride ; (iii) TFA/DCM, 1/1; (iv) N, N'-bis-t- butoxycarbonylpyrazole carboxamidine, diisopropylethylamine, ACN; (v) (CHO) n, EtOH, sodium triacetoxyborohydride.

Scheme 1 The following examples were synthesized using the procedures outlined in Scheme 1.

Intermediate 1

To 5-methoxysalicylaldehyde (leq.) and cesium carbonate (2 eq.) in DMF at RT was added l-bromo-2-N-t-butoxyzarbonylethane (1.2 eq.), and the mixture stirred overnight at RT. The DMF was evaporated in wacuo and the residue partitioned between EtOAc and

water. The organic layer was washed with brine and dried over MgSO4. Concentration gave 1, as a solid, which was crystallized from hexane.

LC retention time 4.23 minutes, [M+Na] + 318.

Example 1 a) The aldehyde from Intermediate 1, (1 eq.) and mono-N-t-butoxycarbonyl-1, 2- diaminoethane (2 eq.) were stirred at RT for 15min in 1,2-dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vaczio and the residue partitioned between dichloromethane and water.

The organic layer was washed with brine and dried over MgSO4. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.38 minutes, [M+H] + 440. b)

The bis-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh.

The volatiles were removed in vacuo and the TFA salt used without further purification.

The TFA salt was stirred in acetonitrile, treated with excess N, N diisopropylethylamine and NN-bis-t-butoxycarbonylpyrazole carboxamidine added. The mixture was stirred overnight at RT then concentrated in vacuo. The residue was partitioned between dichloromethane and water, the organic layer washed with brine and dried over MgS04.

Concentration gave an oil, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 4.12 minutes, [M+H] + 738. c) The fully protected bis-guanidine was treated with 1mL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired bis-guanidine as the tris-trifluoroacetate.

LC retention time 0.47 minutes, [M+H] + 324.

Example 2 As Example 1 using mono-N-t-butoxycarbonyl-1, 3-diaminopropane. LC retention time 0.43 minutes, [M+H] + 338.

Example 3

The aldehyde from Intermediate 1, (1 eq.) and mono-N-t-butoxycarbonyl-1, 4- diaminobutane (2 eq.) were stirred at RT for 15min in 1,2-dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vactlo and the residue partitioned between dichloromethane and water.

The organic layer was washed with brine and dried over MgS04. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.41 minutes, [M+H] + 468. b)

The bis-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh.

The volatiles were removed in vacuo and the TFA salt used without further purification.

The TFA salt was stirred in acetonitrile, treated with excess N, N-diisopropylethylamine and N, N'-bis-t-butoxycarbonylpyrazole carboxamidine added. The mixture was stirred overnight at RT then concentrated in vacuo. The residue was partitioned between dichloromethane and water, the organic layer washed with brine and dried over MgS04. Concentration gave an oil, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 4.12 minutes, [M+H]+ 752. c) The fully protected bis-guanidine was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired bis-guanidine as the tris-trifluoroacetate.

LC retention time 0.45 & 0.62 minutes, [M+H] + 352.

Example 4 a)

The fully protected bis-guanidine compound from example 3b, was treated with excess paraformaldehyde in ethanol for 16h, then sodium triacetoxyborohydride was added and the mixture stirred at RT for 4h. The mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgS04. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention 4.31minutes, [M+H] + 766. b) The fully protected bis-guanidine was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired bis-guanidine as the tris-trifluoroacetate.

LC retention time 0.45, [M+H] + 366.

Example 5

As example 1 using mono-N-t-butoxycarbonyl-1, 2-diaminopentane.

LC retention 0.47 minutes, [M+H]+ 366.

Intermediate 2

To 5-methoxysalicylaldehyde (leq.) and cesium carbonate (2 eq.) in DMF at RT was added l-bromo-3-N-t-butoxycarbonylpropane (1.2 eq.), and the mixture stirred overnight at RT. The DMF was evaporated ifs vacuo and the residue partitioned between EtOAc and water. The organic layer was washed with brine and dried over MgS04. Concentration gave the aldehyde as a solid, which was crystallized from hexane.

LC retention time 4.34 minutes, [M+Na] + 332.

Example 6 a)

The aldehyde from Intermediate 2, (1 eq.) and mono-N-t-butoxycarbonyl-1, 2- diaminoethane (2 eq.) were stirred at RT for 15min in 1,2-dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water.

The organic layer was washed with brine and dried over MgSO4. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.58 minutes, [M+H] + 454. b) The bis-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh.

The volatiles were removed ici vaczco and the TFA salt used without further purification.

The TFA salt was stirred in acetonitrile, treated with excess N, N diisopropylethylamine and N, N'-bis-t-butoxycarbonylpyrazole carboxamidine added. The mixture was stirred overnight at RT then concentrated ii7 vaczlo. The residue was partitioned between dichloromethane and water, the organic layer washed with brine and dried over MgSO4.

Concentration gave an oil, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 4.39 minutes, [M+Hl+ 738.

c) The fully protected bis-guanidine was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed M vaczco to give the desired bis-guanidine as the tris-trifluoroacetate.

LC retention time 0.48 & 1.24 minutes, [M+H] + 338.

Example 7

As example 6 using mono-N-t-butoxycarbonyl-1, 2-diaminopropane.

LC retention time 0.48 & 1.52 minutes, [M+H] + 352.

Example 8

As example 6 using mono-N-t-butoxycarbonyl-1, 2-diaminobutane.

LC retention time 0.49 & 2.17 minutes, [M+H]+ 366.

Example 9

As example 6 using mono-N-t-butoxycarbonyl-1, 2-diaminopentane.

LC retention time 0.49 minutes, [M+H] + 380.

Reagents: (i) Br (CH2) nNHBoc, Cs2CO3, DMF ; (ii) ClCH2C : CCH2NHBoc, Cs2C03, NaI, DMF; (iii) R3NH2, DCE or EtOH, sodium triacetoxyborohydride; (iv) (CHO)n, EtOH, sodium triacetoxyborohydride ; (v) TFA/DCM, 1/1.

Scheme 2 The following examples were synthesized using the procedures outlined in Scheme 2.

Example 10

The aldehyde from Intermediate 1, (1 eq.) and 1-amino-4-N, N'-bis-t- butoxycarbonylguanidinobutane (1.8 eq) were stirred at RT for 15min in 1,2- dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgS04. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.96 minutes, [M+H] + 610. b) The tris-t-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 0.45 minutes, [M+H] + 310.

Example 11 a)

The tris-t-Boc compound from example 10a, was treated with excess paraformaldehyde in ethanol for 16h, then sodium triacetoxyborohydride was added and the mixture stirred at RT for 4h. The mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgS04. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 4.29 minutes, [M+H] + 624. b) The tris-t-Boc compound was treated with 1mL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 0.39 minutes, [M+H] + 324.

Example 12 a)

The aldehyde from Intermediate 2, (1 eq.) and 1-amino-4-N, N'-bis-t- butoxycarbonylguanidinobutane (1.8 eq) were stirred at RT for 15min in 1,2- dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgSO4. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 4.04 minutes, [M+H] + 624.

Example 13 a)

The aldehyde from Intermediate 2, (1 eq.) and 2-t-butoxycarbonylamino-5-aminoimidazole (1.8 eq) were stirred at RT for lhour in methanol, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for lh at RT the mixture was concentrated in vacTo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgSO4. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.95 minutes, [M+H] + 542. b) The bis-t-Boc compound was treated with 1mL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 2.68 minutes, [M+H] + 342.

Example 14 a)

The aldehyde from Intermediate 2, (1 eq.) and 2-t-butoxycarbonylamino-5- (aminomethyl) imidazole (1.8 eq) were stirred at RT for 15min in 1,2-dichloroethane, and then sodium triacetoxyborohydride (1. 5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgS04.

Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.60 minutes, [M+H] + 556. b) The bis-t-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for 1h. The volatiles were removed in vacuo to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 0.46 and 2.41 minutes, [M+H]+ 356.

Example 15 a)

To 5-trifluoromethoxysalicylaldehyde (leq.) and cesium carbonate (2 eq.) in DMF at RT was added 1-bromo-2-N-t-butoxycarbonylpropane (1.2 eq.), and the mixture stirred overnight at RT. The DMF was evaporated in vacuo and the residue partitioned between EtOAc and water. The organic layer was washed with brine and dried over MgSO4.

Concentration gave an oil, which was purified by chromatography on silica gel eluting with mixtures of EtOAc and hexane.

LC retention time 4.71 minutes, [M-Boc+H] + 264. b) The aldehyde (1 eq.) and 1-amino-4-N, N'-bis-t-butoxycarbonylguanidinobutane (1.8 eq) were stirred at RT for 15min in 1,2-dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated i7z vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgSO4. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 4.11 minutes, [M+H] + 678. c) The tris-t-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed ion vacio to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 0.47 minutes, [M+H] + 378.

Example 16 a)

To 5-methoxysalicylaldehyde (leq.) and cesium carbonate (2 eq.) in DMF at RT was added 1-chloro-4-N-t-butoxycarbonylbut-2-yne (1.2 eq.) and sodium iodide (1.2 eq.), and the mixture stirred overnight at RT. The DMF was evaporated in vacuo and the residue partitioned between EtOAc and water. The organic layer was washed with brine and dried over MgS04. Concentration gave the aldehyde as an oil, which was purified by column chromatography on silica, eluting with mixtures of ethyl acetate and hexane.

LC retention time 4.39 minutes, [M+Na] + 342. b)

The aldehyde (1 eq.) and 1-amino-4-NN-bis-t-butoxycarbonylguanidinobutane (1.8 eq) were stirred at RT for 15min in 1, 2-dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated M vaciio and the residue partitioned between dichloromethane and water. The organic layer was

washed with brine and dried over MgS04. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol.

LC retention time 3.97 minutes, [M+H] + 634. c) The tris-t-Boc compound was treated with 1mL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 1.64 minutes, [M+H] + 334.

Reagents: (i) TFA/DCM, 1/1; (ii) 2-nitrophenyl sulfonyl chloride, Et3N, DCM; (iii) RX, Cs2CO3, DMF; (iv) PhSH, DBU, DMF, then DCM, 1M NaOH, t-Boc ? O ; (v) l-amino-4- N, N'-bis-t-butoxycarbonylguanidinobutane, DCE, sodium triacetoxyborohydride.

Scheme 3 The following examples were synthesized using the procedures outlined in Scheme 3.

Example 17

a)

The aldehyde from Intermediate 2, was stirred with DCM/TFA (1: 1) for 30 minutes at RT then the volatiles blown off with nitrogen. The crude amine trifluoroacetate was dissolved in DCM and treated with 2-nitrobenzene sulfonyl chloride (2 eq.) followed by triethylamine (10 eq.). The mixture was stirred at RT for 2 h, diluted with more DCM, then washed rapidly with cold 1N HC1, saturated sodium bicarbonate and brine. The organics were dried MgS04 and concentrated to an oil which was purified by column chromatography on silica, eluting with mixtures of EtOAc and hexane.

LC retention time 4.34 minutes, [M+H] + 394. b)

To the NH compound from 17a (1 eq.) in DMF at RT was added cesium carbonate (2 eq.), followed by methyl iodide (10 eq.). The mixture was stirred for 16 h at RT. The DMF was evaporated in vacuo and the residue partitioned between EtOAc and water. The organic layer was washed with brine and dried over MgS04. Concentration gave an oil which was purified by column chromatography on silica, eluting with mixtures of EtOAc and hexane.

LC retention time 4.45 minutes, [M+H] + 408. c) To the NMe compound from 17b (leq.) in DMF at RT was added thiophenol (4 eq.) and DBU (8 eq.), and the mixture stirred for 2 h at RT. No starting material was seen by LCMS and TLC and so the reaction was diluted with DCM and 1M NaOH, stirred vigorously and di-t-butyl dicarbonate (2 eq.) added. The reaction was stirred at RT for 2 h then the organic layer separated, washed with brine and dried over MgS04. Concentration gave an oil which was purified by column chromatography on silica, eluting with mixtures of EtOAc and hexane.

LC retention time 4.54 minutes, [M-Boc+H] + 224. b)

The aldehyde (1 eq.) and 1-amino-4-N, N'-bis-t-butoxycarbonylguanidinobutane (1.8 eq) were stirred at RT for 15min in 1,2-dichloroethane, and then sodium triacetoxyborohydride (1.5 eq.) was added. After stirring for 16h at RT the mixture was concentrated in vacuo and the residue partitioned between dichloromethane and water. The organic layer was washed with brine and dried over MgS04. Concentration gave a solid, which was purified by chromatography on silica gel eluting with mixtures of dichloromethane and methanol. b) The tris-t-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh. The volatiles were removed in vacuo to give the desired mono-guanidine as the tris- trifluoroacetate.

LC retention time 0.46 minutes, [M+H] + 338.

Example 18 As example 17 using benzyl bromide.

LC retention time 0.46 and 2.50 minutes, [M+H] + 414.

Reagents : (i) Br (CH2) 3NHBoc, Cs2CO3, DMF; (ii) Ethylbromoacetate, Cs2CO3, DMF; (iii) , TMOF/THF, sodium triacetoxyborohydride; (iv) IMLiOH, THF; (v) HNR1R2, PyBroP, diisopropylethylamine, DCM/DMF ; (v) TFA/DCM, 1/1.

Scheme 4 The following examples were synthesized using the procedures outlined in Scheme 4.

Example 19 a)

To 2,5-dihydroxybenzaldehyde (leq.) and cesium carbonate (1.1 eq.) in DMF at RT was added 1-bromo-3-N-t-butoxycarbonylpropane (1. 1 eq.), and the mixture stirred overnight at RT. The mixture was acidified to pH 4 with 10% citric acid and the crude product extracted into EtOAc (4 x). The combined organic layers were washed with water, brine and dried over Na2S04. Concentration gave a brown oil. The desired regioisomer was isolated by preparative HPLC as a white solid in 31 % yield.

HPLC retention time 2.54 minutes (isocratic, 45/55), [M+Na] + 318. b) To the phenol (leq.) and cesium carbonate (1. 1 eq.) in DMF at RT was added ethylbromoacetate (1.1 eq.), and the mixture stirred overnight at RT. The mixture was diluted with ethyl acetate and washed successively with 10% citric acid, saturated sodium bicarbonate, water and brine, then dried over MgSO4. Concentration gave the aldehyde as a brown oil, which was purified by column chromatography on silica eluting with mixtures of ethyl acetate and hexane.

HPLC retention time 2.68minutes (isocratic, 60/40), [M+H] + 382. c)

To the aldehyde (1 eq.) in a solution of trimethylorthoformate (TMOF) and THF (1 : 1, v/v), was added l-N, N'-bis-t-butoxycarbonylcarboxamidinopiperazine (2.0 eq). The mixture was stirred at RT for 30min, and then sodium triacetoxyborohydride (1.4 eq.) was added. After stirring for 3h at RT the mixture was diluted with 10% citric acid and EtOAc. The organic layer was separated and washed with saturated sodium bicarbonate, water and brine and dried over MgS04. Concentration gave a gum, which was purified by chromatography on silica gel eluting with mixtures of ethyl acetate and hexane.

HPLC retention time 2.13 minutes (isocratic, 60/40), [M+H] + 694. d) The ethyl ester (1 eq.) in THF was treated with a 1M solution of lithium hydroxide (1.5 eq), and the mixture was stirred at RT for 2h. After this time, the mixture was acidified to pH 4 with 10% citric acid, and extracted with ethyl acetate. The organic layer was washed successively with water and brine, dried over Na2SO4. The solvent was evaporated in vacua to yield the desired acid as a white solid.

HPLC retention time 2.46minutes (gradient), [M+H] + 666. e)

The acid was treated with 1- (3-aminopropyl)-2-methylpiperidine (2 eq.), bromo-tris- pyrroloidino-phophonium hexafluorophosphate (pyBroP, 4 eq.) and diisopropylethylamine (5 eq.) in a mixture of DCM/DMF (2: 1, v/v) at RT for 16h. The crude amide was purified by preparative HPLC.

HPLC retention time 3.02 minutes (isocratic, 45/55), [M+H]+ 804. f) The tris-t-Boc compound was treated with 1mL of 1/1 DCM/TFA and stirred at RT for 30min. The volatiles were removed in vacuo to give the desired mono-guanidine as the tetra-trifluoroacetate.

HPLC retention time 1.41 minutes (isocratic, 15/85), [M+H] + 504.

Example 20 As example 19 using 2-Diethylaminoethyl 4-aminobenzoate. HPLC retention time 1. 33 minutes (isocratic, 15/85), [M+H] + 584.

Example 21 As example 19 using N- (3-piperidin-1-yl-propyl)-2-aminobenzamide.

HPLC retention time 1.76 minutes (isocratic, 15/85), [M+H] + 609.

Reagents: (i) Br (CH2) 3NHBoc, Cs2CO3, DMF; (ii) ethylbromoacetate, Cs2CO3, DMF; (iii) mono-N-t-butoxycarbonyl-1, 4-diaminobutane, TMOF/THF, sodium triacetoxyboro- hydride ; (iv) Di-t-Butyldicarbonate, DMAP, DCM; (v) lMLiOH, THF; (vi) HNRtR2, PyBroP, diisopropylethylamine, DCM/DMF ; (vii) TFA/DCM, 1/1 ; (viii) N, N'-bis-t- butoxycarbonylpyrazole carboxamidine, diisopropylethylamine, DCM.

Scheme 5 The following examples were synthesized using the procedures outlined in Scheme 5.

Example 22

To 2,5-dihydroxybenzaldehyde (leq.) and cesium carbonate (1.1 eq.) in DMF at RT was added l-bromo-3-N-t-butoxycarbonylpropane (1.1 eq.), and the mixture stirred overnight at RT. The mixture was diluted with EtOAc and washed with 10% citric acid. The aqueous layer was washed with more EtOAc and the combined organic fractions washed with water and brine and dried over MgS04. Concentration gave a brown oil which was purified by preparative HPLC to yield a brown solid.

HPLC retention time 3. 10minutes (isocratic, 40/60), [M+H] + 282. b) To the phenol (leq.) and cesium carbonate (1.1 eq.) in DMF at RT was added ethylbromoacetate (1.1 eq.), and the mixture stirred overnight at RT. The mixture was diluted with ethyl acetate and washed successively with 10% citric acid, saturated sodium bicarbonate, water and brine, then dried over MgS04. Concentration gave the crude product, which was purified by column chromatography on silica eluting with mixtures of ethyl acetate and hexane.

HPLC retention time 5.81minutes (isocratic, 45/55), [M+H] + 368.

To the aldehyde (1 eq.) in a solution of trimethylorthoformate and THF (1 : 1, v/v), was added mono-N-t-butoxycarbonyl-1, 4-diaminobutane (1.5 eq). The mixture was stirred at RT for 15min, and then sodium triacetoxyborohydride (1.4 eq.) was added. After stirring for 3h at RT, the mixture was diluted with ethyl acetate and washed successively with 10% citric acid, saturated sodium bicarbonate, water and brine, then dried over Na2SO4.

Concentration gave a yellow oil, which was dissolved in DCM and treated with DMAP (0.1 eq.) and di-t-butyldicarbonate (1.5 eq). The reaction was stirred at RT for 1. 5h, then diluted with ethyl acetate and washed successively with 10% citric acid, saturated sodium bicarbonate, water and brine, then dried over Na2SO4. Concentration gave the crude product which was purified by column chromatography on silica eluting with mixtures of ethyl acetate and hexane.

HPLC retention time 4.76minutes (gradient), [M+H] + 640. d) The ethyl ester (1 eq.) in THF was treated with a 1M solution of lithium hydroxide (1.5 eq), and the mixture was stirred at RT for 2h. After this time, ethyl acetate was added and the solution was washed successively with 10% citric acid, water and brine. The organic fraction was dried over Na,) S04. The solvent was evaporated iii vaczzo to yield the desired acid as a white foam. HPLC retention time 5.27 minutes (gradient), [M+H] + 612. e)

The acid was treated with 1- (3-aminopropyl)-2-methylpiperidine (2 eq.), bromo-tris- pyrroloidino-phophonium hexafluorophosphate (pyBroP, 4 eq.) and diisopropylethylamine (5 eq.) in a mixture of DCM/DMF (2: 1, v/v) at RT for 16h. The crude amide was purified by preparative HPLC.

HPLC retention time 5.13 minutes (gradient), [M+H] + 750.

The tris-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for lh.

The volatiles were removed in vacDlo and the TFA salt used without further purification.

The TFA salt was stirred in DCM, treated with excess N, N-diisopropylethylamine (20 eq.) for 15 minutes, then N, N'-bis-t-butoxycarbonylpyrazole carboxamidine (2.5 eq.) added.

The mixture was stirred overnight at RT then concentrated in vacuo to yield an oil. This was purified by reverse phase preparative HPLC to give an orange oil.

[M+H] + 934.

g) The tetra-t-Boc compound was treated with ImL of 1/1 DCM/TFA and stirred at RT for 30min. The volatiles were removed in vacuo to give the desired bis-guanidine as the tetra- trifluoroacetate.

HPLC retention time 1.33 minutes (isocratic, 15/85), [M+H] + 534.

Example 23

As example 22 using 2-Diethylaminoethyl 4-aminobenzoate. HPLC retention time 2.52 minutes (isocratic, 20/80), [M+H] + 614.

Example 24

As example 22 using N-Methylhomopiperazine.

HPLC retention time 1.47 minutes (isocratic, 20/80), [M+H] + 492.

Biological Results Tat-Tar Binding Inhibition Assay Principle of the assay To measure the inhibition by the compound of RNA binding to ADP-1, the RNA is titrated in the presence of a constant amount of fluorescent donor (fluorescein-ADP-I peptide) and compound as described in International Patent Application W099/64625, hereby incorporated by reference. The assay is performed under competitive conditions, with a two fold excess of competitor RNA (a fully base-paired TAR sequence) over fluorescein- ADP-1 peptide (the fluorescent donor). The TAR RNA contains a 3'dabcyl group. The dabcyl group is a non-fluorescent acceptor for energy transfer from fluorescein (the fluorescent donor). When ADP-1 and RNA bind, the fluorescence signal from the fluorescein is quenched by the close proximity of the Dabcyl group. The presence of an inhibitory compound disrupts the ADP-1 RNA complex. Complex disruption causes a decrease in energy transfer, which is observed as an increase in donor fluorescence intensity relative to a control (dabcyl) RNA- (fluorescein) ADP-1 binding reaction (in the absence of compound).

Disruption of DABCYL-TAR-FAM-ADP-1 complex formation by conlpounds of the invention.

The examples were assayed for their ability to inhibit the binding of Tat to Tar.

Measurements were made in a 96-well plate reader (Wallac victor) with a fixed wavelength of 490nm and emission at 535 nm. Io was determined by an initial measurement of a 95 WL solution of lOnM Fluoresein-ADP-1 in the presence of 50mM Tris. HCl pH7.5,80mM KCl, 1% DMSO 0.01% Triton X-100, 5µg/mL BSA, 20nM competitor RNA in the presence lFlM compound. I was then measured following the addition of 5 pL of a 20 X DABCYL-TAR RNA stock solution.

The following inhibition constants were observed: Example Ki (µM) No. 1 <50 <10 3 <10 4 <50 5 <10 6 <10 7 <10 8 <10 9 <50 10 <50 11 <50 12 <10 13 <50 14 <10 15 <50 16 <10 17 <50 18 <10 19 <10 20 <50 21 <100 22 <10 23 <1 24 <10

The compounds of the present invention therefore show good biological activity.

The in vivo therapeutic efficacy of the compounds of the invention is measured by conventional i7i vivo antiviral assays including, but not limited to, that described in Letvin, N. L., Daniel, M. D., Sehgal, P. K., Desrosiers, R. C., Hunt, R. D., Waldron, L. M., MacKey, J. J., Schmidt, D. K., Chalifoux, L. V. and King, N. W. Introduction of AIDS-like disease in macaque monkeys with T-cell tropic retrovirus STLV-III, Science, 1985,230,71-73, which is incorporated herein by reference.