Discovery of triazines as potent, selective and orally active PDE4 inhibitors.

Expanding on HTS hit 4 afforded a series of [1,3,5]triazine derivatives as novel PDE4 inhibitors. The SAR development and optimization process with the emphasis on ligand efficiency and physicochemical properties led to the discovery of compound 44 as a potent, selective and orally active PDE4 inhibitor.

Synthesis and structure-activity relationship studies of dihydronaphthyridinediones as a novel structural class of potent and selective PDE7 inhibitors.

The synthesis and SAR studies of a series of structurally novel inhibitors of PDE7 are discussed. The best compounds from the series display low nanomolar inhibitory activity and are selective versus other PDE isoenzymes.