N-3-Substituted Imidazoquinazolinones:  Potent and Selective PDE5 Inhibitors as Potential Agents for Treatment of Erectile Dysfunction

Phosphodiesterase type 5 (PDE5) inhibitors with improved PDE isozyme selectivity relative to sildenafil may result in agents for the treatment of male erectile dysfunction (MED) with a lower incidence of PDE-associated adverse effects. This paper describes the discovery of <BO>14</BO>, a PDE5 inhibitor with improved potency and selectivity in vitro compared to sildenafil. This compound shows activity in a functional assay of erectile function comparable to that of sildenafil.