L-benzimidazole nucleosides

A compound of the formula (I):

• wherein
• R1 represents hydrogen, a halo atom, azido,
• —NR8R9 where R1 and R9 are the same or different and are each independently selected from the group consisting of hydrogen, hydroxyl, C1-12 alkyl, where the alkyl moiety is optionally substituted by one or more substituents selected from the group consisting of halo, amino, azido, hydroxy, cyano, NO2, NHR10, SO2R10, SR10, OR10, COR10 and haloC1-6alkyl where R10 is C1-6alkyl, C3-6alkenyl, C2-6alkynyl, or aryl, C2-8alkenyl, C1-6alkoxy, C3-7cycloalkyl, C2-8alkynyl, C3-7cycloalkenyl, C3-7cycloalkylC1-6alkyl, aryl, arylC1-6alkyl, heteroaryl, heterocarylC1-6alkyl, heterocyclyl and heterocyclylC1-6alkyl or R8R9 together with the N atom to which they are attached form a 3,4,5 or 6 membered heterocyclic ring;
• —NHNR11R12 where R11 and R12 are the same or different and each represent hydrogen or C1-6alkyl;
• —N═NC1-6alkyl or —NHOC1-6alkyl;
• R2 represents hydrogen, halo atom, C1-6alkyl or C2-6alkenyl;
• R3 and R4are the same or different and each represent hydrogen, halogen or NO2;
• wherein the sugar moiety of Formula I
• is selected from the group consisting of:
• with the proviso that when R2 represents hydrogen, R3 and R4 each represent chloro, and the sugar moiety is
• then R1 represents:
• azido,
• —NR8R9 where R8 and R9 are the same or different and are each independently selected from the group consisting of hydroxyl, C1-6alkyl, where the alkyl moiety is substituted by one or more substituents selected from the group consisting of amino, azido, NO2, NHR10, SO2R10, SR10, OR10, haloC1-6alkyl where R10 is as hereinbefore defined, C7-12 alkyl (where the alkyl moiety is optionally substituted by one or more substituents selected from the group consisting of halo, amino, azido, hydroxy, cyano, NO2, NHR10, SO2R10, SR10, OR10, COR10 and haloC1-6alkyl where R10 is as hereinbefore defined), C1-6alkoxy, C3-7cycloalkenyl, heteroaryl, heteroaryl C1-6alkyl and heterocyclyl;
• —NHR11R12 where R11 and R12 are as hereinbefore defined;
• —N═NC1-6alkyl or
• —NHOC1-6alkyl;
• or a pharmaceutically acceptable derivative thereof.