The design and synthesis of N4-anthraniloyl-2′-dC, the improved syntheses of N4carbamoyl- and N4-ureidocarbamoyl-2′-dC, incorporation into oligonucleotides and triplex formation testing

Three modified nucleosides were designed with the aim of achieving triplet formation with the CG base pair of duplex DNA. Direct anthraniloylation of 2'-deoxycytidine, using isatoic anhydride afforded the novel N-4-anthraniloyl-2'-deoxycyridine. Much improved preparations of N-4-carbamoyl-2'-deoxycytidine and of N-4-ureidocarbonyl-2'-deoxycytidine were accomplished. The modified nucleosides were incorporated into oligonucleotides. Thermal denaturation studies and gel mobility shift analysis suggest that these nucleosides do not form base triplets with any of the four base pairs of DNA.