1 2 3 Robins et aL4 reported the first synthesis of the exocyclic amino nucleoside, 4-amino-8- (~-~-ribofuranosylamino) py-rimido [5, 4-d] pyrimidine (2), via a rearrangement of 6-cyano-9- PD-ribofuranosylpurine. Townsend and Robins6 reported the synthesis of 2-amino-6- hydroxy-5-(N-formyl-N-methylamino)-4-(~-ribofuranosylamino) pyrimi-dine by ring cleavage of 7-methylguanosine with aqueous ammonia. Niedballa and Vorbrugged isolated N4-( ...
[Kamikawa, Tadao; Fujie, Satoru; Yamagiwa, Yoshiro; Kim, Mujo; Kawaguchi, Hitoshi Journal of the Chemical Society, Chemical Communications, 1988 , # 3 p. 195 - 196]