Abstract Reaction of cycloazauridine I with glycine and L-Lysine in water at pH 10 afforded the glycine derivative II and the N ε-lysine derivative III, respectively. An identical sample of III was prepared by reaction of N α-formyl-L-lysine with I followed by deformylation of the formed IV. L-Arginine reacts with I in water to give the N α-derivative V. Under analogous conditions, 6-chloro-9-β-D-ribofuranosylpurine and L-lysine afford the N ε derivative X. ...