3-Bromo-3-deazaneplanocin and 3-bromo-3-deazaaristeromycin: Synthesis and antiviral activity

As an outgrowth of our program to explore 3-deazaadenine carbocyclic nucleosides, 3-bromo-3-deazaneplanocin (5) and 3-bromo-3-deazaaristeromycin (6) have been synthesized from a readily available cyclopentenol and cyclopentanone and either 4-amino- or 4-chloro-1H-imidazo[4,5-c]pyridine (6-amino- or 6-chloro-3-deazaadenine) in 5 steps and 7 steps, respectively. Antiviral analysis found 5 to display significant activity towards a number of (-)-ssRNA and a few dsDNA viruses. Compound 6 was less active than 5 against selected examples of those viruses affected by 5.