PROCESS FOR PRODUCING DEAZAPURINE NUCLEOSIDE DERIVATIVES AND ANTIVIRAL COMPOSITIONS COMPRISING SAID COMPOUNDS

Novel deazapurine nucleosides of the formula I in which X denotes nitrogen or a methine group, W denotes nitrogen or the group R , R , R and R can be the same or different, and denote hydrogen, halogen, a lower alkyl, hydroxyl, mercapto, lower alkylthio, lower alkyloxy, aralkyl, aralkyloxy, aryloxy or an optionally mono- or disubstituted amino group, R denotes hydrogen or a hydroxyl group, R and R each denote hydrogen or one of the two radicals R and R denotes halogen, a cyano, azido or an optionally mono- or disubstituted amino group, where one of the radicals R and R can also represent a hydroxyl group if X denotes a methine group, and R and R together can additionally represent a further bond between C-2' and C-3' and Y represents hydrogen, a monophosphate, diphosphate or triphosphate group, and possible tautomers and salts and nucleic acids which contain one or more compounds of the formula I as building block. The compounds according to the invention exhibit antiviral properties and can further be used in DNA sequencing, where they lead to chain termination and/or prevent band compression.