Phthalazine PDE4 inhibitors. Part 2: the synthesis and biological evaluation of 6-methoxy-1,4-disubstituted derivatives.

This communication describes the synthesis and in vitro evaluation of a novel and potent series of phosphodiesterase type IV (PDE4) inhibitors. The compounds described present substituents in position 4 of the phthalazine ring to replace the commonly observed cyclopentyloxy moiety of rolipram analogues. Preliminary evidences of reduced side effects compared to standards and improved pharmacokinetic properties for selected derivatives are also reported.