An 8-aminoimidazo[4,5-g]quinazoline carbocyclic nucleoside: a ring-extended analog of 5′-noraristeromycin

The antiviral properties of 5′-noraristeromycin (3) have been attributed to its inhibition of S-adenosylhomocysteine hydrolase. As part of an effort to establish the limiting structural parameters possible for the biological properties of 3, a ring-extended analog possessing 8-aminoimidazo[4,5-g]quinazoline as the base (7) has been prepared and found to be less active than 3.