| abstract |
Compounds of the formula <IMAGE> in which X = H, NRR<1>, SR, OR or halogen; Z = H, OR<1> or NRR<1>; R, R<1> and R<2> are H, C1-4-alkyl or aryl and pharmaceutically acceptable derivatives thereof are described. The use of the compounds as antiviral and antitumour agents is likewise described as well as pharmaceutical formulations and methods for the preparation of the compounds and their intermediates. |