A new synthetic route to nucleotide adducts derived from N-acetylated and unacetylated 4-aminobiphenyl.

The carcinogen N-acetoxy-N-2-acetylaminofluorene reacts with dG and dG-containing nucleotides to give good yields of the C-8 adducts, but the analogous 4-aminobiphenyl derivative does not. Replacement of the N-acetoxy group by 2,6-dichlorobenzoyloxy circumvents this difficulty. This reaction is shown to be generally applicable, and biphenylamido adducts with dG, d(CpG), d(GpC) and d(ApG) have been prepared. A new, useful deacetylation procedure employing the heterogeneous system sodium carbonate/methanol which leads to the corresponding biphenylamino derivative without appreciable imidazole ring opening is also reported.