Patent ID: 6875859

Claim:
A compound of the general formula wherein: R 1 and R 2 can be the same or different and each independently represents hydrogen, oxygen, halogen, hydroxy, thio, amino, carboxy, lower alkyl, lower alkenyl, lower alkinyl, aryl, lower alkyloxy, aryloxy, aralkyl, aralkyloxy or a reporter group, each of R 3 and R 4 independently represents hydrogen, hydroxy, thio, amino, lower alkyloxy, lower alkenoxy, lower alkinoxy, a protecting group or a reporter group, R 5 represents hydrogen, hydroxy, thio, amino, a reactive trivalent or pentavalent phosphorus group, an ester or amide residue that can be cleaved in a manner or a reporter group, R 6 represents hydrogen or a hydroxy, thio, or amino, R 7 represents hydrogen, a monophosphate, diphosphate or triphosphate group or the alpha, beta or gamma thiophosphate analogue of a phosphoric acid ester or a protective group, or a tautomer or salt thereof, X represents methylene or methine substituted with halogen, hydroxy, thio, amino, carboxy, lower alkyl, lower alkenyl, lower alkinyl, aryl, lower alkyloxy, aryloxy, aralkyl, aralkyloxy or a reporter group, or oxygen and n=0 or 1, Z represents nitrogen or carbon, provided that if Z represents nitrogen, m is zero (0), and if X represents methylene, substituted methylene or substituted methine, Z cannot be carbon and if X represents oxygen, Z cannot be nitrogen.