Anti-viral pyrimidine nucleoside analogues

A compound having the formula:

• 19
• wherein
• Ar is an, optionally substituted, aromatic ring system, the aromatic ring system comprising one six-membered aromatic ring or two fused six-membered aromatic rings;
• R8 and R9 are each independently selected from the group comprising hydrogen, alkyl, cycloalkyl, halogens, amino, alkylamino, dialkylamino, nitro, cyano, alkyoxy, aryloxy, thiol, alkylthiol, arythiol, aryl;
• Q is selected from the group comprising O, S and CY2, where Y may be the same or different and is selected from H, alkyl and halogens;
• X is selected from the group comprising O, NH, S, N-alkyl, (CH2)m where m is 1 to 10, and CY2 where Y may be the same or different and is selected from hydrogen, alkyl and halogens;
• Z is selected from the group comprising O, S, NH, and N-alkyl;
• U″ is H and U′ is selected from H and CH2T, or U′ and U″ are joined so as to form a ring moiety including Q wherein U′—U″ together is respectively selected from the group comprising —CTH—CT′Y″- and —CT=CT- and —CT′=CT′-, so as to provide ring moieties selected from the group comprising:
• 20
• wherein:
• T is selected from the group comprising OH, H, halogens, O-alkyl, O-acyl, O-aryl, CN, NH2 and N3;
• T′ is selected from the group comprising H and halogens and, where more than one T′ is present, they may be the same or different;
• T″ is selected from the group comprising H and halogens;
• and
• W is selected from the group comprising H, a phosphate group and a pharmacologically acceptable salt, derivative or pro drug thereof;
• with the provisos that:
• (1) when T is OAc and T′ and T″ are present and are H, Ar is not 4(2-benzoxazolyl)phenyl;
• and
• (2) when Q, X and Z are each O, and R8, R9, T′, T″ and W are each H and T is OH or O-acyl, Ar is:
• one six-membered carbocyclic aromatic ring substituted by one or more moieties independently selected from the group comprising alkyl, aryl, cycloalkyl, chlorine, bromine, iodine, cyano, alkylamino, dialkylamino, alkoxy, aryloxy, alkylthio and arylthio, any of which alkyl, cycloalkyl or aryl moieties may be substituted by one or more members selected from the group comprising chlorine, bromine, iodine, CN, CO2alkyl (C1 to C6), CONH2, CONH alkyl (C1 to C6), SH, S alkyl (C1 to C6) and NO2;
• one six-membered aromatic ring system which contains one, two, three or four hetero atoms and which ring system may be optionally substituted;
• or
• two fused six-membered aromatic rings, which may be optionally substituted.