WO2020221894A1

WO2020221894A1 - Antiviral compounds

Info

Publication number: WO2020221894A1
Application number: PCT/EP2020/062122
Authority: WO
Inventors: Julia MOESSLACHER; Verena BATTISTI; Thierry Langer; Ernst Urban; Gerhard Puerstinger; Rana ABDELNABI; Leen DELANG; Dirk Jochmans; Pieter Leyssen; Arnaud Marchand; Johan Neyts
Original assignee: Universität Wien; Universität Innsbruck; Katholieke Universiteit Leuven
Priority date: 2019-04-30
Filing date: 2020-04-30
Publication date: 2020-11-05

Abstract

The invention is provides novel antiviral compounds, as well as derivatives thereof. The compounds of the invention are preferably formulated as pharmaceuticals. The invention provides the compounds for use in the prevention and treatment of infectious diseases, in particular viral diseases. In some aspects the invention is based on the antiviral activity of the provided compounds against the Chikungunya virus, and hence, their application in the treatment or prevention of any physiological manifestation of such viral infection.

Description

ANTIVIRAL COMPOUNDS

FIELD OF THE INVENTION

[1] The invention is provides novel antiviral compounds, as well as derivatives thereof. The compounds of the invention are preferably formulated as pharmaceuticals. The invention provides the compounds for use in the prevention and treatment of infectious diseases, in particular viral diseases. In some aspects the invention is based on the antiviral activity of the provided compounds against the Chikungunya virus, and hence, their application in the treatment or prevention of any physiological manifestation of such viral infection.

DESCRIPTION

[2] The family of the Togaviridae consists of 2 genera, the Alphavirus genus including, among others, the chikungunya virus (CHIKV), Ross River virus, Mayaro virus Eastern equine encephalitis virus, Western equine encephalitis virus, and Venezuelan equine encephalitis virus, and the Rubivirus genus including Rubella virus. Alphaviruses include clinically important viruses that cause severe diseases such as encephalitis and/or arthritis. Some alphaviruses, including the chikungunya virus in particular, have become significant global health threats because of their high disease burden, their (re-)emergence, and the lack of vaccines and antiviral drugs.

[3] CHIKV is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952. CHIKV is transmitted to humans by virus-carrying Aedes mosquitoes. CHIKV infections cause an acute disease with fever, headache and painful arthritis, usually resolving within one week. Occasional cases of neurological and heart complications have been reported, as well as gastrointestinal complaints. Serious complications are not common, but in older people, the disease can contribute to the cause of death. The acute stage can evolve into an incapacitating chronic arthralgia in about 50% of infected patients, lasting for several months or years after the initial infection. This chronic CHIKV disease poses a substantial social and economic burden and results in an important loss of life quality.

[4] Chikungunya infections occur in Africa, Asia and since 2013 also in the Americas. Human infections in Africa have been at relatively low levels for a number of years, but in 1999-2000, there was a large outbreak in the Democratic Republic of the Congo, and in 2007, there was an outbreak in Gabon. Starting in February 2005, a major outbreak of Chikungunya occurred in islands of the Indian Ocean. A large number of imported cases in Europe were associated with this outbreak, mostly in 2006 when the Indian Ocean epidemic was at its peak. Several other countries in South-East Asia were affected as well. In 2007, transmission was reported for the first time in Europe, in a localized outbreak in north- eastern Italy. In December 2013, CHIKV emerged in the Caribbean and spread from there very rapidly to countries in South as well as Central America resulting in more than 2.1 million infected persons.

[5] Currently, there are no antivirals available to treat or prevent infections with CHIKV or other alphaviruses. Treatment is directed primarily at relieving the symptoms, including the joint pain. Although acute CHIKV infections are self-limiting, administration of a potent antiviral molecule would reduce the viral load in infected patients, which will as a consequence decrease the severity of the symptoms. Furthermore, this may possibly reduce the transmission efficiency by mosquitoes. Potent and safe CHIKV inhibitors may also be used as household prophylaxis. Although several candidate vaccines have been developed protect against chikungunya virus (Powers A. Vaccine and Therapeutic Options To Control Chikungunya Virus. Clin Microbiol Rev. 2017, 31(1)), there is until now no approved commercial Chikungunya vaccine available.

[6] There is therefore a clear need in the field for novel, potent, selective compounds with a good activity vs. toxicity profile and this specifically for the viruses of the family of the Togaviridae, more specifically against Chikungunya viruses.

[7] One objective of the present invention may be seen in the provision of an alternative or improved pharmaceutical composition based on compounds, which act as inhibitors of Chikungunya virus, or other ss(+)RNA viruses, or alpha viruses, and which are suitable for the treatment of viral diseases and their symptoms, such as headache, muscle pain, joint swelling, and a rash.

[8] Another objective of the present invention may be seen in the provision of new compounds, which exhibit an inhibitory activity on other viruses. Another objective of the present invention may be seen in the provision of new compounds, which do not require a very complex synthesis, as it is often the case for e.g. natural substances.

[9] These and other objectives of the present invention, as they will become apparent from the ensuing description, are solved by the subject matter of the independent claims. The dependent claims relate to some preferred embodiments of the present invention.

[10] The present invention provides such novel compounds which show activity against Togaviridae, more specifically against CHIKV.

BRIEF DESCRIPTION OF THE INVENTION

[11] Generally, and by way of brief description, the main aspects of the present invention can be described as follows: [12] In a first aspect, the invention pertains to a compound, having the following formula I:

D-E-C-B-A (I),

wherein

A and E are independently selected from the group comprising, or consisting of, an aliphatic chain, such as a C₁ to C₁₀, a 4 - 8, preferably a 5 or 6 membered aromatic or non-aromatic heterocycle containing one or more, preferably 2, 3, or 4, heteroatoms, such as N, S, or O, or any combination thereof;

C is a linker comprising one or more N atoms, one or more C atoms, and/or is a 5 to 8 membered ring, which can be fused, bridged, aliphatic or aromatic;

B is C₁ to C5 alkyl, preferably C₁ alkyl, carbonyl, sulfinyl, or a sulfonyl group;

D is a substituted or un-substituted, linear, branched or cyclic alkyl or alkenyl, optionally comprising one or more heteroatoms such as N, O or S;

or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof.

[13] In a second aspect, the invention pertains to A compound, having the following formula II or III:

wherein

B is is C₁ to C₅ alkyl, preferably C₁ alkyl, carbonyl, sulfinyl, or a sulfonyl group;

A and D is independently selected from H, OH, SH, a non-substituted, monosubstituted or polysubstituted C₁-C18-alkyl, wherein the alkyl can be straight, branched or cyclic, alkenyl, trifluormethyl, a non-substituted, monosubstituted or polysubstituted aryl or heteroaryl residue, a non-substituted, monosubstituted or polysubstituted benzyl group, an acyl group, such as, for example, formyl, acetyl, trichloroacetyl, trifluoracetyl, fumaryl, maleyl, succinyl, benzoyl, or a branched or heteroatom- or aryl-substituted acyl group, an alkoxy substituent, such as, for example,–OMet, -OEt, -OnPr, -iPr, -OnBu, -OiBu, -OsecBu, -OtBu, the alkyl group thereof is branched, non-branched or cyclic, an alkyl group bound through a sulfur atom, such as, for example,–SMe, -SEt, or a sulfonyl group, such as, for example,–SO₃H,– SO₂Me, -SO₂CF₃, -SO₂C₆H₄CH₃ or SO₂C₆H₄CH₂Br, or a nitrogen substituent, such as, for example,–NH₂,–NHR,–NRR' (with R, R' = alkyl, aryl etc.),–NC or–NO₂, or fluoro, chloro, bromo, iodo,–CN or a hetero substituent. More preferred is that R₄, R₅, R₇ and R₈ are H, and R₆ is trifluormethyl (-CF₃);

[14] In a third aspect, the invention pertains to a A compound, selected from the following group of compounds:

or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. [15] In a fourth aspect, the invention pertains to a pharmaceutical composition comprising one or more compounds according to any one of the preceding claims, together with a pharmaceutically acceptable carrier and/or excipient.

[16] In a fifth aspect, the invention pertains to a product for use in medicine, comprising the compounds and compositions of the invention.

[17] In a sixth aspect, the invention pertains a method of treating a subject suffering from an infectious disease, comprising administering to the subject a therapeutically effective or preventive amount of a compound, or of a pharmaceutical composition, according to the aspects of the invention. DETAILED DESCRIPTION OF THE INVENTION

[18] In the following, the elements of the invention will be described. These elements are listed with specific embodiments, however, it should be understood that they may be combined in any manner and in any number to create additional embodiments. The variously described examples and preferred embodiments should not be construed to limit the present invention to only the explicitly described embodiments. This description should be understood to support and encompass embodiments which combine two or more of the explicitly described embodiments or which combine the one or more of the explicitly described embodiments with any number of the disclosed and/or preferred elements. Furthermore, any permutations and combinations of all described elements in this application should be considered disclosed by the description of the present application unless the context indicates otherwise.

[19] In the first aspect, the invention pertains to A compound, having the following formula I: D-E-C-B-A

wherein A and E are independently selected from the group comprising, or consisting of, an aliphatic chain, such as a C₁ to C10, a 4- 8, preferably a 5 or 6 membered aromatic or non- aromatic heterocycle containing one or more, preferably 2, 3, or 4, heteroatoms, such as N, S, or O, or any combination thereof; C is a linker comprising one or more N atoms, one or more C atoms, and/or is a 5 to 8 membered ring, which can be fused, bridged, aliphatic or aromatic; B is C₁ to C₅ alkyl, preferably C₁ alkyl, carbonyl, sulfinyl, or a sulfonyl group; D is a substituted or un-substituted, linear, branched or cyclic alkyl or alkenyl, optionally comprising one or more heteroatoms such as N, O or S; or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. [20] In particular preferred embodiments of the invention, groups A and E are independently selected from H, CN, C(O)R¹, C(O)OR², -OC(O)R³, C(O)NR⁴R⁵ , NR⁶R⁷, OR⁸, halogen atoms, substituted or unsubstituted C₁ to C₆ alkyl groups, substituted or unsubstituted C₃ to C₆ cycloalkyl groups, substituted or unsubstituted C₆ to C₁₄ aryl groups and substituted or unsubstituted heterocyclic groups; wherein R¹ to R⁸ are independently selected from the group consisting of H, substituted or unsubstituted C₁ to C₆ alkyl and substituted or unsubstituted C₆ to C₁₄ aryl groups. [21] In other particular embodiments of the invention group B is either C=O or S(=O)₂. [22] The invention in another aspect also provides a compound, having the following formula II or III:

wherein B is is C₁ to C₅ alkyl, preferably C₁ alkyl, carbonyl, sulfinyl, or a sulfonyl group; A and D is independently selected from H, OH, SH, a non-substituted, monosubstituted or polysubstituted C₁-C₁₈-alkyl, wherein the alkyl can be straight, branched or cyclic, alkenyl, trifluormethyl, a non-substituted, monosubstituted or polysubstituted aryl or heteroaryl residue, a non-substituted, monosubstituted or polysubstituted benzyl group, an acyl group, such as, for example, formyl, acetyl, trichloroacetyl, trifluoracetyl, fumaryl, maleyl, succinyl, benzoyl, or a branched or heteroatom- or aryl-substituted acyl group, an alkoxy substituent, such as, for example,–OMet, -OEt, -OnPr, -iPr, -OnBu, - OiBu, -OsecBu, -OtBu, the alkyl group thereof is branched, non-branched or cyclic, an alkyl group bound through a sulfur atom, such as, for example,–SMe, -SEt, or a sulfonyl group, such as, for example,–SO₃H,–SO₂Me, -SO₂CF₃, -SO₂C₆H₄CH₃ or SO₂C₆H₄CH₂Br, or a nitrogen substituent, such as, for example,–NH₂,–NHR,–NRR' (with R, R' = alkyl, aryl etc.),–NC or–NO2, or fluoro, chloro, bromo, iodo,–CN or a hetero substituent. More preferred is that R4, R5, R7 and R8 are H, and R6 is trifluormethyl (-CF3); or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. [23] In some preferred embodiments of the invention D is a substituted or un- substituted, linear, branched or cyclic alkyl or alkenyl, optionally comprising one or more heteroatoms such as N, O or S; and/or A is selected from H, CN, C(O)R¹, C(O)OR², - OC(O)R³, C(O)NR⁴R⁵ , NR⁶R⁷, OR⁸, halogen atoms, substituted or unsubstituted C₁ to C₆ alkyl groups, substituted or unsubstituted C₃ to C₆ cycloalkyl groups, substituted or unsubstituted C₆ to C₁₄ aryl groups and substituted or unsubstituted heterocyclic groups; wherein R¹ to R⁸ are independently selected from the group consisting of H, substituted or unsubstituted C₁ to C₆ alkyl and substituted or unsubstituted C₆ to C₁₄ aryl groups.

[24] The compound according to any one of the preceding claims, wherein A is selected from anyone of the following compounds:

[25] In further preferred embodiments group D is selected from any of the following groups:

[26] In other preferred embodiments the compound of the invention is selected from the following group of compounds:

or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. [27] In other preferred embodiments the compound of the invention is selected from the following group of compounds:

or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. [28] The compound according to any one of the preceding claims, wherein the compound is selected from any compound 1 to 68 according to table X or Y (“test results”) of the example section herein. [29] A compound of the invention that is preferred in certain embodiments is a compound that has an antiviral EC₅₀ of equal to or less than 20µM, preferably 10µM, most preferably 5µM, more preferably less than 1µM. [30] Certain preferred inventive compounds are further selected from the following structures:

[31] In some embodiments and aspects of the invention the preferred compound is selected from the group consisting of [in accordance with the herein disclosed nomenclature of compounds] Compound: 46, 63, 64, 65, 68, and VB29, VB50, VB57, VB66, VB75 and VB81, or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. Most preferred in context of the invention is compound 68 and VB81, or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof. [32] Yet another aspect of the invention also provides a pharmaceutical composition comprising one or more compounds according to any one of the preceding claims, together with a pharmaceutically acceptable carrier and/or excipient. Such inventive compositions may comprise one or more further antiviral compounds. [33] To be used in therapy, the compound of the invention may be formulated into a pharmaceutical composition appropriate to facilitate administration to animals or humans. The term“composition” means a mixture of substances. The term“pharmaceutical composition” means a mixture of substances including a therapeutically active substance (such as a compound of the invention) for pharmaceutical use. [34] Accordingly, herein disclosed is a pharmaceutical composition comprising a compound of the invention (of, or for use with the invention), and a pharmaceutically acceptable excipient, stabiliser or carrier. In a preferred embodiment, the pharmaceutical composition comprises a compound of the invention of Table X. [35] The disclosure also relates to a pharmaceutical composition including: (i) a variant of any of the general (or specific) formula or structures disclosed herein (formula I, II or III), or (ii) a compound as set forth in Table X, or a salt (or a solvate, salt, complex, polymorph, crystalline form, racemic mixture, diastereomers, enantiomer, tautomer, isotopically labelled form, and combination) of (i) or (ii), and a pharmaceutically acceptable excipient, stabiliser or carrier. [36] By way of example, the pharmaceutical composition may comprise between 0.1% and 100% (w/w) active ingredient (for example, a compound of the invention), such as about 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8% 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98% or 99%, preferably between about 1% and about 20%, between about 10% and 50% or between about 40% and 90%. [37] As used herein the language“pharmaceutically acceptable” excipient, stabiliser or carrier is intended to include any and all solvents, solubilisers, fillers, stabilisers, binders, absorbents, bases, buffering agents, lubricants, controlled release vehicles, diluents, emulsifying agents, humectants, dispersion media, coatings, antibacterial or antifungal agents, isotonic and absorption delaying agents, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well-known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the compositions is contemplated. Supplementary agents can also be incorporated into the compositions. [38] The pharmaceutical composition for use with the invention is, typically, formulated to be compatible with its intended route of administration. Examples of routes of administration include oral, parenteral, e.g., intrathecal, intra-arterial, intravenous, intradermal, subcutaneous, oral, transdermal (topical) and transmucosal administration. [39] Solutions or suspensions used for parenteral, intradermal, or subcutaneous application, as well as comprising a compound for use with the invention (eg compound of the invention), 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; anti-bacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfate; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. [40] Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Kolliphor® EL (formerly Cremophor EL™; BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). In all cases, the injectable composition should, typically, be sterile and be fluid to the extent that easy syringability exists. It should, typically, be stable under the conditions of manufacture and storage and be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the requited particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, and thimerosal. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, and sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin. [41] Sterile injectable solutions can be prepared by incorporating the compound for use with the invention (e.g., a compound of the invention) in the required amount in an appropriate solvent with one or a combination of ingredients described herein, as required, followed by filtered sterilisation. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those described herein. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. [42] Oral compositions, as well as comprising a compound for use with the invention (eg a compound of the invention), generally include an inert diluent or an edible carrier. They can 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. Oral compositions can also be prepared using a fluid carrier for use as a mouthwash, wherein the compound in the fluid carrier is applied orally and swished and expectorated or swallowed. Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, and troches 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 Stertes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavouring agent such as peppermint, methyl salicylate, or orange flavouring. [43] Furthermore, the compounds for use with the invention (eg a compound of the invention) can be administrated rectally. A rectal composition can be any rectally acceptable dosage form including, but not limited to, cream, gel, emulsion, enema, suspension, suppository, and tablet. One preferred dosage form is a suppository having a shape and size designed for introduction into the rectal orifice of the human body. A suppository usually softens, melts, or dissolves at body temperature. Suppository excipients include, but are not limited to, theobroma oil (cocoa butter), glycerinated gelatin, hydrogenated vegetable oils, mixtures of polyethylene glycols of various molecular weights, and fatty acid esters of polyethylene glycol. [44] For administration by inhalation, the compounds for use with the invention (eg a compound of the invention) are typically delivered in the form of an aerosol spray from pressured container or dispenser which contains a suitable propellant, e.g., a gas such as carbon dioxide, or a nebuliser. [45] Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the pharmaceutical compositions can be formulated into ointments, salves, gels, or creams as generally known in the art. [46] In certain embodiments, the pharmaceutical composition is formulated for sustained or controlled release of a compound for use with the invention (eg a compound of the invention). Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially (including liposomes targeted to infected cells with monoclonal antibodies to viral antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art. [47] It is especially advantageous to formulate oral, rectal or parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein includes physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms as described herein are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and the limitations inherent in the art of compounding such an active compound for the treatment of individuals. [48] In some embodiments, the pharmaceutical composition comprising a compound of the invention is in unit dose form of between 10 and 1000 mg compound of the invention. In some embodiments, the pharmaceutical composition comprising an compound of the invention is in unit dose form of between 10 and 200 mg compound of the invention. In some embodiments, the pharmaceutical composition comprising an ABP is in unit dose form of between 200 and 400 mg compound of the invention. In some embodiments, the pharmaceutical composition comprising an compound of the invention is in unit dose form of between 400 and 600 mg compound of the invention. In some embodiments, the pharmaceutical composition comprising an compound of the invention is in unit dose form of between 600 and 800 mg compound of the invention. In some embodiments, the pharmaceutical composition comprising an compound of the invention is in unit dose form of between 800 and 1000 mg compound of the invention. [49] Exemplary unit dosage forms for pharmaceutical compositions comprising compound of the inventions are tablets, capsules (eg as powder, granules, microtablets or micropellets), suspensions or as single-use pre-loaded syringes. In certain embodiments, kits are provided for producing a single-dose administration unit. The kit can contain both a first container having a dried active ingredient and a second container having an aqueous formulation. Alternatively, the kit can contain single and multi-chambered pre-loaded syringes. [50] Toxicity and therapeutic efficacy (eg effectiveness) of such active ingredients can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, eg, for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50/ED50. Active agents which exhibit large therapeutic indices are preferred. While compounds that exhibit toxic side effects may be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue in order to minimise potential damage to uninfected cells and, thereby, reduce side effects. [51] The data obtained from the cell culture assays and animal studies can be used in formulating a range of dosage of the active ingredients such as for use in humans. The dosage of such active ingredients lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilised. For any active ingredients used in the therapeutic approaches of the invention, the (therapeutically) effective dose can be estimated initially from cell culture assays. A dose may be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 (ie, the concentration of the active ingredients which achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful (eg effective) amounts or doses, such as for administration to humans. The pharmaceutical compositions can be included in a container, pack, or dispenser together with instructions for administration. [52] In the context of the invention, an effective amount of the compound of the invention or the pharmaceutical composition can be one that will elicit the biological, physiological, pharmacological, therapeutic or medical response of a cell, tissue, system, body, animal, individual, patient or human that is being sought by the researcher, scientist, pharmacologist, pharmacist, veterinarian, medical doctor, or other clinician, eg, lessening of the effects/symptoms of a disorder, disease or condition, such as a proliferative disorder, for example, a cancer or tumour, or killing or inhibiting growth of a cell involved with a proliferative disorder, such as a tumour cell. The effective amount can be determined by standard procedures, including those described below. [53] In accordance with all aspects and embodiments of the medical uses and treatments provided herein, the effective amount administered at least once to a subject in need of treatment with a compound of the invention is, typically, between about 0.01 mg/kg and about 100 mg/kg per administration, such as between about 1 mg/kg and about 10 mg/kg per administration. In some embodiments, the effective amount administered at least once to said subject of a compound of the invention is between about 0.01 mg/kg and about 0.1 mg/kg per administration, between about 0.1 mg/kg and about 1 mg/kg per administration, between about 1 mg/kg and about 5 mg/kg per administration, between about 5 mg/kg and about 10 mg/kg per administration, between about 10 mg/kg and about 50 mg/kg per administration, or between about 50 mg/kg and about 100 mg/kg per administration. [54] For the prevention or treatment of disease, the appropriate dosage of a compound of the invention (or a pharmaceutical composition comprised thereof) will depend on the type of disease to be treated, the severity and course of the disease, whether the compound of the invention and/or pharmaceutical composition is administered for preventive or therapeutic purposes, previous therapy, the patient's clinical history, age, size/weight and response to the compound of the invention and/or pharmaceutical composition, and the discretion of the attending physician. The compound of the invention and/or pharmaceutical composition is suitably administered to the patient at one time or over a series of treatments. If such compound of the invention and/or pharmaceutical composition is administered over a series of treatments, the total number of administrations for a given course of treatment may consist of a total of about 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than about 10 treatments. For example, a treatment may be given once every day (or 2, 3 or 4 times a day) for a week, a month or even several months. In certain embodiments, the course of treatment may continue indefinitely. [55] The amount of the compound of the invention and/or pharmaceutical composition administered will depend on variables such as the type and extent of disease or indication to be treated, the overall health, age, size/weight of the patient, the in vivo potency of the compound of the invention and/or pharmaceutical composition, and the route of administration. The initial dosage can be increased beyond the upper level in order to rapidly achieve the desired blood-level or tissue level. Alternatively, the initial dosage can be smaller than the optimum, and the daily dosage may be progressively increased during the course of treatment. Human dosage can be optimised, e.g., in a conventional Phase I dose escalation study designed to run from relatively low initial doses, for example from about 0.01 mg/kg to about 20 mg/kg of active ingredient. Dosing frequency can vary, depending on factors such as route of administration, dosage amount and the disease being treated. Exemplary dosing frequencies are once per day, once per week and once every two weeks. Formulation of an compound of the invention for use with the present is within the ordinary skill in the art. In some embodiments of the invention such compound of the invention is lyophilised and reconstituted in buffered saline at the time of administration. The compound of the invention and/or pharmaceutical composition of may further result in a reduced relapsing of the disease to be treated or reduce the incidence of drug resistance or increase the time until drug resistance is developing; and in the case of cancer may result in an increase in the period of progression-free survival and/or overall survival. [56] As described above, it was surprisingly found that the new class of active agents according to formula (I) were found to provide a inhibition of Chikungunya virus replication rendering the corresponding pharmaceutical compositions suitable for use as a medicament, e.g. for the treatment of conditions like those induced by viral infections. [57] In order to be used for the treatment of conditions induced by viral infections, it may be necessary that the compound as described herein is available in the central nervous system. Thus, it may be advantageous if the compound as described herein is able to penetrate the blood brain barrier. [58] A skilled person may adjust the hydrophobicity of the compound by selecting the appropriate substituents as specified herein, in such a way that the compound may diffuse and/or may be transported from the circulating blood in the brain into the extracellular fluid of the central nervous system. [59] The present invention in particular provides the antiviral compounds for a treatment in medicine, for example as a product for use in medicine, wherein the product comprises a compound, or a pharmaceutical composition, according to the invention. [60] Preferably the use is a treatment or prevention of an infectious disease, preferably a viral disease. A viral disease in context of the invention is a virus of the family of togaviridae, preferably is of the genus of alphavirus, and most preferably is the Chikungunya virus. [61] In some embodiments, the compounds of the invention may be further used in the treatment or prevention of a viral infection caused by Viral infections that can be treated with a subject method include infections of any of a variety of viruses, including, but not limited to, members of Picornaviridae; members of Orthomyxoviridae; members of Paramyxoviridae; members of Coronaviridae; members of Adenoviridae; members of Reoviridae; members of Caliciviridae; members of Astroviridae; members of Herpesviridae; members of Retroviridae; and members of Papillomaviridae. In some embodiments, the virus is SARS-Cov, preferably SARS-Cov2. [62] In other preferred embodiments, the compounds of the invention are useful for a selective inhibition of CHIK virus, and not of other alpha viruses. Preferably the compounds of the invention have an activity as a pan-strain CHIK antiviral agent. [63] In any one of the above embodiments, the individual is a human of from about one month to about 6 months, from about 6 months to about 1 year, from about 1 year to about 5 years, from about 5 years to about 12 years, from about 13 years to about 18 years, from about 18 years to about 25 years, from about 25 years to about 50 years, from about 50 years to about 75 years of age, or older than 75 years of age. [64] In some embodiments, an active agent is administered in an amount of from about 10 mg to about 500 mg per dose, e.g., from about 10 mg to about 20 mg, from about 20 mg to about 25 mg, from about 25 mg to about 50 mg, from about 50 mg to about 75 mg, from about 75 mg to about 100 mg, from about 100 mg to about 150 mg, from about 150 mg to about 200 mg, from about 200 mg to about 250 mg, from about 250 mg to about 300 mg, from about 300 mg to about 400 mg, from about 400 mg to about 500 mg, from about 500 mg to about 750 mg, from about 750 mg to about 1 mg, from about 1 mg to about 10 mg, from about 10 mg to about 25 mg, from about 25 mg to about 50 mg, from about 50 mg to about 100 mg, from about 100 mg to about 200 mg, from about 200 mg to about 300 mg, from about 300 mg to about 400 mg, or from about 400 mg to about 500 mg per dose. [65] In some embodiments, an active agent is administered in an amount of from about 10 mg/m2 per dose to about 150 mg/m2 per dose, e.g., from about 10 mg/m2 per dose to about 15 mg/m2 per dose, from about 15 mg/m2 per dose to about 20 mg/m2 per dose, from about 20 mg/m2 per dose to about 25 mg/m2 per dose, from about 25 mg/m2 per dose to about 30 mg/m2 per dose, from about 30 mg/m2 per dose to about 35 mg/m2 per dose, from about 35 mg/m2 per dose to about 40 mg/m2 per dose, from about 40 mg/m2 per dose to about 50 mg/m2 per dose, from about 50 mg/m2 per dose to about 60 mg/m2 per dose, from about 60 mg/m2 per dose to about 70 mg/m2 per dose, from about 70 mg/m2 per dose to about 80 mg/m2 per dose, from about 80 mg/m2 per dose to about 90 mg/m2 per dose, from about 90 mg/m2 per dose to about 100 mg/m2 per dose, from about 100 mg/m2 per dose to about 1 10 mg/m2 per dose, from about 1 10 mg/m2 per dose to about 120 mg/m2 per dose, from about 120 mg/m2 per dose to about 130 mg/m2 per dose, from about 130 mg/m2 per dose to about 140 mg/m2 per dose, or from about 140 mg/m2 per dose to about 150 mg/m2 per dose. [66] In some embodiments, an active agent is administered in an amount of from about 10 mg/m per week to about 200 mg/m per week, e.g., from about 10 mg/m per week to about 15 mg/m2 per week, from about 15 mg/m2 per week to about 20 mg/m2 per week, from about 20 mg/m2 per week to about 25 mg/m2 per week, from about 25 mg/m2 per week to about 30 mg/m2 per week, from about 30 mg/m2 per week to about 35 mg/m2 per week, from about 35 mg/m2 per week to about 40 mg/m2 per week, from about 40 mg/m2 per week to about 50 mg/m2 per week, from about 50 mg/m2 per week to about 60 mg/m2 per week, from about 60 mg/m2 per week to about 70 mg/m2 per week, from about 70 mg/m2 per week to about 80 mg/m per week, from about 80 mg/m per week to about 90 mg/m per week, from about 90 mg/m2 per week to about 100 mg/m2 per week, from about 100 mg/m2 per week to about 1 10 mg/m2 per week, from about 1 10 mg/m2 per week to about 120 mg/m2 per week, from about 120 mg/m2 per week to about 130 mg/m2 per week, from about 130 mg/m2 per week to about 140 mg/m2 per dose, from about 140 mg/m2 per week to about 150 mg/m2 per week, from about 150 mg/m2 per week to about 160 mg/m2 per week, from about 160 mg/m2 per week to about 170 mg/m2 per week, from about 170 mg/m2 per week to about 180 mg/m2 per week, from about 180 mg/m2 per week to about 190 mg/m2 per week, or from about 190 mg/m2 per week to about 200 mg/m2 per week. [67] Preferably,“treatment” in context of the invention refers to a complete or partial eradication of the disease vector, or to keeping the vector under a critical concentration. Treatment further relates to a stabilization of reduction is the discomfort related to infection with the disease vector such as headache, muscle pain, joint swelling, and a rash [68] Another aspect of the invention then pertains to a method of treating a subject suffering from an infectious disease, the method comprising administering to the subject a therapeutically effective or preventive amount of a compound, or of a pharmaceutical composition, according to the invention. [69] The infectious disease is preferably a viral disease is a virus of the family of togaviridae, preferably is of the genus of alphavirus, and most preferably is the Chikungunya virus. [70] Also provided is use of a compound according to the invention, or of a pharmaceutical composition according to the invention, in the manufacturing of a medicament for treating a disease, preferably an infectious disease. [71] The terms “of the [present] invention”, “in accordance with the invention”, “according to the invention” and the like, as used herein are intended to refer to all aspects and embodiments of the invention described and/or claimed herein.

[72] As used herein, the term“comprising” is to be construed as encompassing both “including” and“consisting of”, both meanings being specifically intended, and hence individually disclosed embodiments in accordance with the present invention. Where used herein,“and/or” is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example,“A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein. In the context of the present invention, the terms“about” and“approximately” denote an interval of accuracy that the person skilled in the art will understand to still ensure the technical effect of the feature in question. The term typically indicates deviation from the indicated numerical value by ±20%, ±15%, ±10%, and for example ±5%. As will be appreciated by the person of ordinary skill, the specific such deviation for a numerical value for a given technical effect will depend on the nature of the technical effect. For example, a natural or biological technical effect may generally have a larger such deviation than one for a man-made or engineering technical effect. As will be appreciated by the person of ordinary skill, the specific such deviation for a numerical value for a given technical effect will depend on the nature of the technical effect. For example, a natural or biological technical effect may generally have a larger such deviation than one for a man-made or engineering technical effect. Where an indefinite or definite article is used when referring to a singular noun, e.g. "a", "an" or "the", this includes a plural of that noun unless something else is specifically stated.

[73] A“pharmaceutically effective amount” of a compound as described in the present invention refers to the quantity of the compound that may be used for treating a subject and may depend on the weight and age of the subject and the route of administration, among other things.

[74] The term“halogen atom” includes fluoride, bromide, chloride or iodide. The term “halo” means–F, -Cl, -Br or–I. A“haloalkyl” group in the meaning of the present invention is an alkyl group as described herein, wherein at least one hydrogen atom is substituted by a halogen atom. Exemplary haloalkyl groups include a pentafluoroethyl or trifluoromethyl group. [75] The term“alkyl” refers to straight chain and branched saturated hydrocarbon groups, having a specified number of carbon atoms (e.g., C1 to C6 alkyl refers to an alkyl group having 1 to 6 carbon atoms). Examples of alkyl groups include methyl, ethyl, n-propyl, i- propyl, n-butyl, s-butyl, i-butyl, t-butyl, pent-1-yl, pent-2-yl, pent-3-yl, 3-methylbut-1-yl, 3- methylbut-2-yl, 2-methylbut-2-yl, 2,2,2-trimethyleth-1-yl, n-hexyl, and the like. When the expression“propyl groups” is used herein, it is meant to encompass n-propyl, i-propyl, when the expression“butyl groups” is used herein, it is meant to encompass n-butyl, s-butyl, i- butyl, t-butyl, and so on.

[76] The term“cycloalkyl” refers to saturated monocyclic hydrocarbon groups, generally having a specified number of carbon atoms that comprise the ring or rings (e.g., C3 to C6 cycloalkyl refers to a cycloalkyl group having 3 to 6 carbon atoms as ring members). The cycloalkyl group may be attached to a parent group or to a substrate at any ring atom unless such attachment would violate valence requirements. Examples of monocyclic cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[77] The term“aryl” in the meaning of the present invention refers to fully unsaturated monocyclic aromatic hydrocarbons and to polycyclic hydrocarbons having at least one aromatic ring, both monocyclic and polycyclic aryl groups generally having a specified number of carbon atoms that comprise their ring members (e.g., C6 to C14 aryl refers to an aryl group having 6 to 14 carbon atoms as ring members). The aryl group may be attached to a parent group or to a substrate at any ring atom and may include one or more non- hydrogen substituents unless such attachment or substitution would violate valence requirements. Examples of aryl groups include phenyl, biphenyl, cyclobutabenzenyl, indenyl, naphthalenyl, benzocycloheptanyl, biphenylenyl, fluorenyl, and the like.

[78] The term„substituted“ when used in connection with a chemical substituent or moiety (e.g., an alkyl group), means that one or more hydrogen atoms of the substituent or moiety have been replaced with one or more non-hydrogen atoms or groups. The term particularly refers to substituted moieties (including substituted C₁ to C₆ alkyl groups, substituted C₃ to C₆ cycloalkyl groups, substituted C₆ to C₁₄ aryl groups, or substituted heterocyclic groups) bearing one or more of the following groups or substituents: halogen, -C₁-C₆ alkyl, -C₁-C₆ alkenyl, -hydroxyl, -NH₂, -NH(C₁-C₆ alkyl), -N(C₁-C₆ alkyl)(C₁-C₆ alkyl), -N(C₁-C₃ alkyl)C(O)(C₁-C₆ alkyl), -NHC(O)(C₁-C₆ alkyl), -NHC(O)H, -C(O)NH₂, - C(O)NH(C₁-C₆ alkyl), -C(O)N(C₁-C₆ alkyl)(C₁-C₆ alkyl), -CN, CHN(C₁-C₆ alkyl), -O(C₁-C₆ alkyl), -C(O)OH, -C(O)O(C₁-C₆ alkyl), -(C₁-C₆ alkyl)C(O)O(C₁-C₆ alkyl), -C(O)(C₁-C₆ alkyl), - C₆- C₁₄ aryl, -C5-C9 heteroaryl, -C₃-C₈ cycloalkyl, -haloalkyl, -aminoalkyl, -OC(O)(C₁-C₆ alkyl), - C₁-C₆ carboxyamidoalkyl and/or -NO₂.

[79] A“heterocyclic” group in the meaning of the present invention refers to saturated or partially unsaturated monocyclic groups having ring atoms composed of carbon atoms and 1 to 4 heteroatoms independently selected from nitrogen, oxygen, and sulfur. The monocyclic group generally has a specified number of carbon atoms in their ring or rings (e.g., C₂ to C₄ heterocyclic group refers to a heterocyclic group having 2 to 5 carbon atoms and 1 to 4 heteroatoms as ring members). The heterocyclic group may be attached to a parent group or to a substrate at any ring atom and may include one or more non-hydrogen substituents unless such attachment or substitution would violate valence requirements or result in a chemically unstable compound. Examples of heterocyclic groups include tetrazolyl, imidazolyl, pyrazol, aziridinyl (e.g., aziridin-1-yl and aziridin-2-yl), tetrahydrofuranyl, pyrrolidinyl, tetrahydropyranyl, tetrahydrothiopyranyl, piperidinyl, 1,4-dioxanyl, 1,2,3,4- tetrahydropyridinyl, and 1,2,5,6-tetrahydropyridinyl.

[80] It is to be understood that application of the teachings of the present invention to a specific problem or environment, and the inclusion of variations of the present invention or additional features thereto (such as further aspects and embodiments), will be within the capabilities of one having ordinary skill in the art in light of the teachings contained herein.

[81] Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described.

[82] All references, patents, and publications cited herein are hereby incorporated by reference in their entirety.

BRIEF DESCRIPTION OF THE FIGURES AND SEQUENCES

[83] The figures show:

[84] Figure 1: shows the structure of the compounds of the invention

[85] Figure 2: shows the results of the biological data of compound 68

[86] Figure 3: shows alphavirus selectivity of compound 68 and activity against different CHIK virus isolates. EXAMPLES

[88] Certain aspects and embodiments of the invention will now be illustrated by way of example and with reference to the description, figures and tables set out herein. Such examples of the methods, uses and other aspects of the present invention are representative only, and should not be taken to limit the scope of the present invention to only such representative examples.

[89] The examples show:

[90] Example 1: Synthesis of compound (1)

[91] Compound 1 was prepared using a 4-step-synthesis; this synthesis route is established to give access to the entire compound series. Synthesis is shown in Scheme 1:

[92] Scheme 1: Synthesis of the compound 1.

a) Ethanol, 24-48h room temperature; b) Ethanol, µwave, 30min, 155°C, 250 Watt, 2bar;

c) 4.0M HCl, Dioxane/Tetrahydrofurane, 24h room temperature; d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature. [93] First step of the synthesis

[94] 2-chloro-N-ethyl-6-methylpyrimidin-4-amine is prepared by adding 2 equivalents of ethylamine (2.0M solution in methanol) to 2,4-dichloro-6-methylpyrimidine in dry ethanol in 48 hours. Yield of 2-chloro-N-ethyl-6-methylpyrimidin-4-amine is 45% after purification; additionally 17% of 4-chloro-N-ethyl-6-methylpyrimidin-2-amine are obtained as a side product.

[95] Second step of the synthesis:

[96] To 2-chloro-N-ethyl-6-methylpyrimidin-4-amine 2 equivalents of tert-butyl piperazine-1-carboxylate* in dry ethanol are added, the reaction is performed under microwave irradiation with 155°C, 30min, 250 Watt and 12 bar as conditions; yield of tert- butyl 4-(4-(ethylamino)-6-methylpyrimidin-2-yl)piperazine-1-carboxylate is 85% after purification.

[97] Third step of the synthesis:

[98] The protecting group is removed from the amine in this step of the synthesis. tert- butyl 4-(4-(ethylamino)-6-methylpyrimidin-2-yl)piperazine-1-carboxylate is dissolved in dry tetrahydrofurane, 10 equivalents of a 4.0M HCl solution in dioxane are added, removing the boc group within 24 hours at room temperature. 52% of N-ethyl-6-methyl-2-(piperazin-1- yl)pyrimidin-4-amine are obtained in this step of the synthesis.

[99] Fourth step of the synthesis:

[100] The fourth step in the synthesis can be performed under two conditions:

[101] To N-ethyl-6-methyl-2-(piperazin-1-yl)pyrimidin-4-amine in dry dichloromethane 1 equivalent of 4-fluorobenzenesulfonyl chloride and 1 equivalent of triethylamine as base are added. After a reaction period of 24 hours at room temperature and subsequent purification, 32% of the desired compound N-ethyl-2-(4-((4-fluorophenyl)sulfonyl)piperazin-1-yl)-6- methylpyrimidin-4-amine are obtained.

[102] N-ethyl-6-methyl-2-(piperazin-1-yl)pyrimidin-4-amine in dry dichloromethane, 1 equivalent of 4-fluorobenzenesulfonyl chloride and 1 equivalent of triethylamine are heated to 110°C for 10 minutes under microwave irradiation. Yield after purification remains about same, but the time required for synthesis is decreased.

[103] Synthesis of Example Compounds by Modifications of Group A

[104] Compounds 2– compound 23, except compound 11, of this group were synthesized following Scheme 2. Synthesis of compound 11 is displayed in Scheme 3.

[105] The first three steps of the synthesis remain the same as for the compound (1), as well as the reaction conditions as described above, and therefore also the possible mechanism of action is the same. For the preparation of analogues, in the fourth step, instead of the 4-fluorobenzenesulfonyl chloride, another sulfonyl chloride is used.

[106] The conditions for the reaction remain unchanged, steps 1-3 of the synthesis are depicted in Scheme 1, the last step of synthesis of compounds 2– 23 are shown in Scheme 2:

[107] Scheme 2: Synthesis of the compounds from GROUP A (first row:

compounds 2– 10; second row:

compounds 12– 23; third row: compounds 19– 23).

d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature.

[108] Compound 11 is prepared starting with compound 7 by reduction of the nitro group to an amino group using tin (II) chloride, as shown in Scheme 3:

7 11

[109] Scheme 3: Synthesis of compound 11 out of compound 7.

e) SnCl₂ * ₂H₂O, ethylacetat, 24h reflux.

[110] Synthesis of Example Compounds by Modifications of Group B [111] Compounds 24 and compound 25 were synthesized following Scheme 4.

[112] The first three steps of the synthesis remain the same as for the compound (1), as well as the reaction conditions and therefore the possible mechanism of action is the same. In the fourth step of the synthesis instead of the 4-fluorobenzenesulfonyl chloride, 4- fluorobenzyl chloride, or 4-fluorobenzoyl chloride are used.

[113] Scheme 4: Synthesis of example compounds by modification of GROUP B (compound 24 and compound 25).

d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature. Synthesis of Example

[114] Compounds by Modifications of Group C

[115] Compound 26 + 27: The steps for the synthesis remain the same as for compound (1), as well as the reaction conditions and therefore the possible mechanism of action is the same as described before. Synthesis of compound 26 is shown in Scheme 5; synthesis of compound 27 is shown in Scheme 6.

[116] Compound 28: The synthesis of compound 28 (Scheme 7) differs from the syntheses of the other compounds in Group C:

[117] The first step of the synthesis remains identical. Then, in the second step the 2- chloro-N-ethyl-6-methylpyrimidin-4-amine is reacted directly with the tetrahydroquinoxaline (as modified linker) under microwave irradiation, without protecting one of the two amino groups first.

[118] The reaction is then followed by a column chromatography to remove the side products yielding pure 2-(3,4-dihydroquinoxalin-1(2H)-yl)-N-ethyl-6-methylpyrimidin-4- amine. [119] The third step of the synthesis is then identical to the forth step of the previously used standard procedure – performed with 4-fluorobenzenesulfonyl chloride and triethylamine as base in dichloromethane at room temperature for 24 hours.

[120] Synthesis of compound 26 (Scheme 5):

[121] Scheme 5: Synthesis of compound 26.

b) Ethanol, µwave, 30min, 155°C, 250 Watt, 12bar; c) 4.0M HCl, Dioxane/Tetrahydrofurane, 24h room temperature;

d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature.

[122] Synthesis of compound 27 (Scheme 6):

[123] Scheme 6: Synthesis of compound 27.

b) Ethanol, µwave, 30min, 155°C, 250 Watt, 12bar; c) 4.0M HCl,

Dioxane/Tetrahydrofurane, 24h room temperature; d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature

[124] Synthesis of compound 28 (Scheme 7):

[125] Scheme 7: Synthesis of compound 28.

b) Ethanol, µwave, 30min, 155°C, 250 Watt, 12bar; d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature.

[126] Example 2: Synthesis of Example Compounds by Modifications of Group D

[127] Group D contains compounds in which ethylamine as side chain is replaced by other side chains; so in the first step of the synthesis instead of ethylamine as reactant methylamine, isopropylamine, tert butylamine, sodium ethoxide or pyrrolidine are used, to prepare the analogue compounds 29– 33.

[128] Compounds 29– 33 of Group D were synthesized following Scheme 8:

Scheme 8: Synthesis of compounds from Group D. R= comp. nr.

-NH-CH₃ 29 a) Ethanol, 24-48h room temperature; b) Ethanol, µwave, -NH-CH- 30 30min, 155°C, 250 Watt, 12bar; c) 4.0M HCl, (CH₃)2

Dioxane/Tetrahydrofurane, 24h room temperature; d) -NH-C- 31 Dichloromethane, N(CH₂CH₃)₃, 24h room temperature (CH₃)₃

-O-CH₂-CH₃ 32 -pyrrolidine 33

[129] Example 3: Synthesis of Example Compounds by Modifications of Group E

[130] Compounds of Group E (compound 34 - 38) are synthesized following Scheme 9. The synthesis remains the same as for the compound 1, as well as the reaction conditions.

[131] In order to prepare the analogues of this group, a differently substituted pyrimidine building block are used as starting reactant in the first step of the synthesis.

[132] The pyrimidine ring of preparation of compound 34 (4-chloro-N-ethyl-6- methylpyrimidin-2-amine) could be obtained as product out in the first step of the synthesis of 1 (separation by column chromatography, purification, and structure elucidation assessed by NOE - ¹H NMR).

Scheme 9: Synthesis of compounds from E₂ = E₄ = E₆ = R = comp. Group E. nr.

N N C -CH₃ 34 a) EtOH, 24-48h RT; b) EtOH, µwave, C N N -CH₃ 35 30min, 155°C, 250 Watt, 12bar; c) 4.0M N C N -H 36 HCL in dioxane / THF 24h RT; d) DCM, N N C -H 37 N(CH₂CH₃)₃, 24h RT C N N -H 38 [133] Example 4: Synthesis of Example Compounds by Modifications of Groups A and B

[134] Compound 39, 40 and 41 bearing modifications on the 4-fluorobenzene ring and sulphonamide linker are synthesized following Scheme 10. The first three steps of the syntheses are identical to the syntheses of compound 1; so for the preparation of the analogues in this group, in the fourth step of the synthesis 4-fluorobenzenesulfonyl chloride as reactant is replaced by either a 4-chlorobenzoyl chloride (compound 39) or alkyl chlorides (compound 40 and compound 41).

[135] Reaction conditions are identical to the synthesis of 1. In Scheme 10, only the last step of the synthesis is shown:

[136] Scheme 10: Synthesis of compounds from Group AB.

d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature

[137] Example 5: Synthesis of Example Compounds by Modifications of Groups A and E

[138] Compound 42, 43 and 44 (Group AE) bearing modifications on the 4-fluorophenyl ring and on the pyrimidine ring are synthesized following Scheme 11. Steps of the synthesis, as well as the reaction conditions are identical to the synthesis of the compound 1.

[139] For the preparation of the analogues of the Group AE, a different pyrimidine building block is used as starting material, and 4-chlorobenzenesulfonyl chloride as reactant in the last step of the synthesis is used.

Scheme 11: Synthesis of compounds from E₂ = E₄ = E₆ = R = comp. Group AE. nr.

N N C -CH₃ 42 a) EtOH, 24-48h RT; b) EtOH, µwave, N C N -H 43 30min, 155°C, 250 Watt, 12bar; c) 4.0M N C C -H 44 HCL in dioxane / THF 24h RT; d) DCM,

N(CH₂CH₃)₃, 24h RT [140] Example 6: Synthesis of Example Compounds by Modifications of Groups B and E

[141] Compound 45 - 48 (Group BE) bearing modifications on the sulfonamide linker and on the pyrimidine ring are synthesized following Scheme 12.

[142] For the preparation of the analogues of this Group BE, various pyrimidine rings as starting materials are used; in the last step of the synthesis 4-fluorobenzenesulfonyl chloride as reactant is replaced by either 4-fluorobenzoyl chloride (compounds 45, 46, 47) or 4- fluoro benzyl chloride (compound 48). Beside this, steps of the synthesis, as well as the reaction conditions are identical to the synthesis of the compound 1.

Scheme 12: Synthesis of Group AE. X = E₂ = E₄ = E₆ = R = comp. a) EtOH, 24-48h RT; b) EtOH, µwave, nr. 30min, 155°C, 250 Watt, 12bar; c) 4.0M C=O N C N -H 45 HCL in dioxane / THF 24h RT; d) DCM, C=O N N C - CH₃ 46 N(CH₂CH₃)₃, 24h RT C=O N N C -H 47

CH₂ N N C -H 48 [143] Example 7: Synthesis of Example Compounds by Modifications of Groups D and E

[144] For example compounds of Group DE (compounds 49 - 54) analogues bearing modifications on the ethylamine side chain and on the pyrimidine ring were synthesized, following Scheme 13.

[145] Compound 50, 51 and 52 undergo only the last three steps of the synthesis. The reactants (4-chloro-N,6-dimethylpyrimidin-2-amine for compound 50, 4-chloro-N- isopropyl-6-methylpyrimidin-2-amine for compound 51 and 4-chloro-6-methyl-2- (pyrrolidin-1-yl)pyrimidin for compound 52) for the second step could be obtained in the first step of the synthesis of the compounds 29, 30 and 33 (from Group D); The rest of the synthesis is identical to the synthesis of compound (1).

Scheme 13: Synthesis of Group R_(D) = E₂ = E₄ = E₆ = R_(E) = comp. BE. nr. a) EtOH, 24-48h RT; b) EtOH, -H N C N -H 49 µwave, 30min, 155°C, 250 Watt, -NH-CH₃ N N C -CH₃ 50 12bar; -NH-CH- N N C -CH₃ 51 c) 4.0M HCL in dioxane / THF (CH₃)2

24h RT; d) DCM, N(CH₂CH₃)₃, -N-C₄H₈ N N C -CH₃ 52 24h RT -NH-CH- N C N -H 53

(CH₃)₂ -NH-CH-C₂H₄ N C N -H 54

[146] Example 8: Synthesis of Example Compounds by Modifications of Three Groups

[147] The example compounds of Group ABE bear modifications on the 4-fluorophenyl ring, the sulphonamide linker and the pyrimidine ring;

[148] Group ADE examples contain analogues with modifications on the on the 4- fluorophenyl ring, the ethylamine side chain and the pyrimidine ring;

[149] Group BDE examples contain compounds analogues with modifications on the sulfonamide linker, the ethylamine side chain and the pyrimidine ring.

[150] Syntheses of these groups do not differ from those syntheses previously described. For modifications on the pyrimidine ring and/or on the ethylamine side chain, a different pyrimidine ring and/or a different amino alkyl as starting materials is used in the first step of the synthesis.

[151] To prepare compounds with modifications on the sulfonamide linker and/or the 4- fluorophenyl ring, 4-fluorobenzenesulfonyl chloride as reactant in the last step of the synthesis is replaced by another sulfonyl or benzoyl chloride. Beside this, the syntheses are identical to the synthesis of the compound 1.

[152] Since the syntheses procedures have been described above and are used for all the three Groups (ABE, ADE, BDE), in the following, only the schemes of the syntheses are displayed without giving redundant explanations.

[153] Synthesis of Example Compounds by Modifications of Groups A, B, and E

[154] Compound 55, 56 and 57 from Group ABE are synthesized following Scheme 14:

Scheme 14: Synthesis of Group AE. E₂ = E₄ = E₆ = R = comp. a) EtOH, 24-48h RT; b) EtOH, µwave, 30min, nr. 155°C, 250 Watt, 12bar; c) 4.0M HCL in N C N -H 55 dioxane / THF 24h RT; d) DCM, N(CH₂CH₃)₃, N N C -CH₃ 56 24h RT N N C H 57

[155] Example 9: Synthesis of Example Compounds by Modifications of

Groups A, D, and E

[156] Compound 58 (with chlorine as substituent on the benzene ring, isoproylamine side chain and a pyrimidine ring with altered nitrogen positions - ADE) is synthesized following Scheme 15:

[157] Scheme 15: Synthesis of compound 58 (ADE).

[158] a) Ethanol, 24-48h room temperature; b) Ethanol, µwave, 30min, 155°C, 250 Watt, 12bar; c) 4.0M HCl, Dioxane/Tetrahydrofurane, 24h room temperature; d)

Dichloromethane, N(CH₂CH₃)₃, 24h room temperature.

[159] Example 10: Synthesis of Example Compounds by Modifications of Groups B, D, and E

[160] Compound 59 (with amide as linker, isopropylamine as side chain and a pyrimidine ring with altered nitrogen positions - BDE) is synthesized following Scheme 16:

Scheme 16: Synthesis of compound 59 (BDE)

a) Ethanol, 24-48h room temperature; b) Ethanol, µwave, 30min, 155°C, 250 Watt, 12bar; c) 4.0M HCl, Dioxane/Tetrahydrofurane, 24h room temperature; d) Dichloromethane, N(CH₂CH₃)₃, 24h room temperature.

[161] Example 11: Synthesis of Example Compounds by Modifications of Groups A, B, D, and E

[162] Compound 60 contains modifications on four parts of the molecule: on the 4- fluorophenyl ring, the sulfonamide linker, on the ethylamine side chain, and on the pyrimidine ring (“Group” ABDE).

[163] Compound 60 is prepared following Scheme 17.

[164] Scheme 17: Synthesis of compound 60 (ABDE).

[165] Example 12: Biological Assessments - Tests against Chikungunya Virus

[166] Used cell lines and virus

[167] Chikungunya Virus, Indian Ocean strain 899, isolated in 2006, was kindly provided by Prof. S. Günther (Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany). CHIKV was cultured on African green monkey kidney (Vero) cells (ATCC CCL-81) in minimum essential medium MEM Rega3 (Invitrogen, Belgium) supplemented with 10% Foetal Bovine Serum (FBS; Integro, The Netherlands), 1% l-glutamine and 1% sodium bicarbonate (Invitrogen). Antiviral assays were performed in MEM Rega-3 medium supplemented with 2% FBS.

[168] Virus-cell-based CPE reduction assay

[169] Vero cells were seeded in 96-well plates (Becton Dickinson, New Jersey) at a density of 2.5 × 10⁴ cells/well in 100 µl assay medium and were allowed to adhere overnight in an incubator (37 °C, 5% CO₂, 95-99% RH). Subsequently, a compound dilution series was added after which the cultures were infected with 100 CCID₅₀ (50% cell culture infectious dose) of CHIKV in 100 µl assay medium and returned to the incubator.

[170] On day 6 post-infection, the cellular metabolic activity in each assay well was measured using a colorimetric method as described by the manufacturer (Promega, The Netherlands):“The Non-Radioactive Cell Proliferation Assay is a homogeneous, colorimetric method for determining the number of viable cells in proliferation, cytotoxicity or chemosensitivity assays. The CellTiter 96® AQ_ueous Assay is composed of solutions of a novel tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4- sulfophenyl)-2H-tetrazolium, inner salt; MTS] and an electron coupling reagent (phenazine methosulfate) PMS. MTS is bioreduced by cells into a formazan product that is soluble in tissue culture medium. The absorbance of the formazan product at 490nm can be measured directly from 96-well assay plates without additional processing. The conversion of MTS into the aqueous soluble formazan product is accomplished by dehydrogenase enzymes found in metabolically active cells. The quantity of formazan product as measured by the amount of 490nm absorbance is directly proportional to the number of living cells in culture.”[75]. The 50% effective concentration (EC₅₀) is defined as the concentration of compound that is required to inhibit virus-induced cell death by 50% and was determined using logarithmic interpolation. The anti-metabolic effect of the compounds on uninfected, compound-treated cells was also evaluated by means of the MTS/PMS method. The 50% cytostatic/cytotoxic concentration (CC₅₀) is defined to be the concentration of compound that reduces the overall metabolic activity of the uninfected, compound-treated cells by 50% as compared to the untreated, uninfected cell control condition.

[171] Quantification of the antiviral effect of a compound

[172] A summary / overview of i) quantification, ii) quality control and validation and iii) the measured parameters is given.

[173] The antiviral effect of a compound can be quantified by indirect or direct measurement. The main criterion whether an indirect or direct methodology will be used is based on the potency of the virus to produce a cytopathic effect (CPE), which can be described as alteration of the cell morphology following infection with a virus, most frequently and ultimately leading to an accelerated host cell death as compared to uninfected cells.

[174] Indirect measurement of virus replication, and thus the antiviral effect of a compound, is based on the quantification of a host cell parameter that changes with progression of virus replication. Similar as for the quantification of the anti-metabolic effect positive selection criteria (host cell metabolism, cell reporter proteins,…) or negative selection criteria (dead cell proteins,…) can be used. Consequently, it is to be expected that the anti-metabolic effect of the compound inevitably and directly will be reflected in the shape of the antiviral curve (see further in the“Manual” in Experimental Part).

[175] Direct measurement of virus replication is based on the quantification of a viral parameter that changes with progression of virus replication and takes advantage of the change of the number of (1) viral genomes (viral RNA or DNA: real-time quantitative PCR, padlock techniques,…), (2) viral antigens (viral proteins: Western blot, FACS, ELISA,…), (3) virus infectivity (infectious virions: titration for infectious virus content, plaque forming assays,…), or (4) reporter protein (viruses engineered to carry or produce a reporter protein,…). The anti-metabolic effect of the compound will (almost always) not be reflected directly in the shape of the antiviral curve.

[176] Quality control step and validation:

[177] The calculation of an EC₅₀ (or even an EC₉₀) does not imply that a compound immediately can be considered to possess genuine or selective antiviral activity, before a quality control and/or validation step is performed.

[178] Quality control step: The quality control step for virus-cell-based assays in which the virus induces a clear cytopathic effect most often involves microscopic evaluation of the assay wells for which an antiviral effect >50% is observed (and thus for all compounds that yield an EC₅₀). This microscopic evaluation involves interpretation of adverse effects of the compound on the cells (altered cell morphology, cell density, cell death) concomitantly with virus-induced cell alterations (which are frequently typical for a particular virus and can be discriminated from compound-induced effects) and overall cell death.

[179] Validation step: The validation step, which provides additional confirmation of hits identified in virus-cell-based assays that allow quality control by microscopic evaluation, is however essential for virus-cell-based assays that do not. The first part of the validation step is evaluation of the reproducibility of the antiviral results by repeating the assay employing the same methodology that produced the initial results. Secondly, the antiviral activity has to be confirmed in an antiviral assay using an alternative methodology, which is most often based on another parameter and involves quantification of a viral parameter.

[180] Measured parameters:

[181] Beside some additional obtained parameters/data only described in the manual, the following measured and/or calculated parameters are considered as the most important ones for establishing structure-activity-relationship and therefore for optimization of the initial hit, the aim of this thesis: CC₅₀ (cytostatic/cytotoxic concentration 50), EC₅₀ (effective concentration 50), EC₉₀ (effective concentration 90), SI (selectivity index), [] MAX and MAX %. [182] Results are provided in the table X below:

Compound 68

[183] A particularly preferred compound is compound 68. Further results are provided in figure 2.

[184] Table Y shows the results of the studies for compounds

[185] Example 13: Antiviral Spectrum

[186] Compound 68 was tested against multiple CHIK strains and other alpha viruses. The results are shown in figure 3. Interestingly, the compounds of the herein disclosed novel class 0f viral inhibitors are highly selective for the CHIK virus and are able to target multiple strains. In addition, the compounds seem to have selective effects and do not target other alpha viruses such as Roos River virus, Mayaro virus and others.

Claims

CLAIMS 1. A compound, having the following formula I: D-E-C-B-A (I), wherein A and E are independently selected from the group comprising, or consisting of, an aliphatic chain, such as a C₁ to C10, a 4- 8, preferably a 5 or 6 membered aromatic or non- aromatic heterocycle containing one or more, preferably 2, 3, or 4, heteroatoms, such as N, S, or O, or any combination thereof; C is a linker comprising one or more N atoms, one or more C atoms, and/or is a 5 to 8 membered ring, which can be fused, bridged, aliphatic or aromatic; B is C₁ to C₅ alkyl, preferably C₁ alkyl, carbonyl, sulfinyl, or a sulfonyl group; D is a substituted or un-substituted, linear, branched or cyclic alkyl or alkenyl, optionally comprising one or more heteroatoms such as N, O or S; or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof.

2. The compound according to claim 1, wherein A and E are independently selected from H, CN, C(O)R¹, C(O)OR², -OC(O)R³, C(O)NR⁴R⁵ , NR⁶R⁷, OR⁸, halogen atoms, substituted or unsubstituted C₁ to C₆ alkyl groups, substituted or unsubstituted C₃ to C₆ cycloalkyl groups, substituted or unsubstituted C₆ to C₁₄ aryl groups and substituted or unsubstituted heterocyclic groups; wherein R¹ to R⁸ are independently selected from the group consisting of H, substituted or unsubstituted C₁ to C₆ alkyl and substituted or unsubstituted C₆ to C₁₄ aryl groups.

3. The compound according to claim 1 or 2, wherein B is either C=O or S(=O)₂.

4. A compound, having the following formula II or III:

(II) (III) wherein B is is C₁ to C5 alkyl, preferably C₁ alkyl, carbonyl, sulfinyl, or a sulfonyl group; A and D is independently selected from H, OH, SH, a non-substituted, monosubstituted or polysubstituted C₁-C18-alkyl, wherein the alkyl can be straight, branched or cyclic, alkenyl, trifluormethyl, a non-substituted, monosubstituted or polysubstituted aryl or heteroaryl residue, a non-substituted, monosubstituted or polysubstituted benzyl group, an acyl group, such as, for example, formyl, acetyl, trichloroacetyl, trifluoracetyl, fumaryl, maleyl, succinyl, benzoyl, or a branched or heteroatom- or aryl-substituted acyl group, an alkoxy substituent, such as, for example,–OMet, -OEt, -OnPr, -iPr, -OnBu, - OiBu, -OsecBu, -OtBu, the alkyl group thereof is branched, non-branched or cyclic, an alkyl group bound through a sulfur atom, such as, for example,–SMe, -SEt, or a sulfonyl group, such as, for example,–SO₃H,–SO₂Me, -SO₂CF₃, -SO₂C₆H4CH₃ or SO₂C₆H4CH₂Br, or a nitrogen substituent, such as, for example,–NH₂,–NHR,–NRR' (with R, R' = alkyl, aryl etc.),–NC or–NO₂, or fluoro, chloro, bromo, iodo,–CN or a hetero substituent. More preferred is that R₄, R₅, R₇ and R₈ are H, and R₆ is trifluormethyl (-CF₃); or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof.

5. The compound according to claim 4, wherein D is a substituted or un-substituted, linear, branched or cyclic alkyl or alkenyl, optionally comprising one or more heteroatoms such as N, O or S; and/or A is selected from H, CN, C(O)R¹, C(O)OR², -OC(O)R³, C(O)NR⁴R⁵ , NR⁶R⁷, OR⁸, halogen atoms, substituted or unsubstituted C₁ to C₆ alkyl groups, substituted or unsubstituted C₃ to C₆ cycloalkyl groups, substituted or unsubstituted C₆ to C₁₄ aryl groups and substituted or unsubstituted heterocyclic groups; wherein R¹ to R⁸ are independently selected from the group consisting of H, substituted or unsubstituted C₁ to C₆ alkyl and substituted or unsubstituted C₆ to C₁₄ aryl groups.

6. The compound according to any one of the preceding claims, wherein A is selected from anyone of the following compounds:

7. The compound according to any one of the preceding claims, wherein D is selected from any of the following groups:

8. A compound, selected from the following group of compounds:

9. The compound according to any one of the preceding claims, wherein the compound has an antiviral EC₅₀ of equal to or less than 20µM, preferably 10µM, most preferably 5µM.

10. The compound according to any one of the preceding claims, wherein the compound is selected from the following compounds:

11. The compound according to any one of the preceding claims, wherein the compound has the following formula:

, or solvates, salts, complexes, polymorphs, crystalline forms, racemic mixtures, diastereomers, enantiomers, tautomers, isotopically labelled forms, and prodrugs thereof, or any combinations thereof.

12. A pharmaceutical composition comprising one or more compounds according to any one of the preceding claims, together with a pharmaceutically acceptable carrier and/or excipient.

13. The pharmaceutical composition according to claim 10, further comprising one or more further antiviral compounds.

14. A product for use in medicine, wherein the product comprises a compound, or a pharmaceutical composition, according to any one of the preceding claims.

15. The product for use according to claim 10, wherein the use is a treatment or prevention of an infectious disease, preferably a viral disease, such as a disease of a virus of the family of togaviridae, preferably is of the genus alphavirus, and most preferably of the Chikungunya virus.