Synthesis and biological activities of novel β-carbolines as PDE5 inhibitors

Abstract A series of N 2 -furoyl and N 2 pyrimidinyl β-carbolines was discovered to possess potent inhibitory activity against PDE5. During the synthesis we developed a tandem resin quenching protocol, which allowed us to synthesize large number of target compounds in a rapid fashion. Representative compounds exhibit superior selectivity to sildenafil versus other isozymes of PDEs, and demonstrated in vivo efficacy in increasing introcavernosal pressure in dogs.