Development of orally bioavailable bicyclic pyrazolones as inhibitors of tumor necrosis factor-α production

2-Aryl-3-pyrimidinyl based tumor necrosis factor-alpha (TNF-alpha) inhibitors, which contain a novel bicyclic pyrazolope core, are described. Many showed low-nanomolar activity against lipopolysaccharide-induced TNF-alpha production in monocytic cells. Secondary screening data are presented for the pyrimidinyl bicyclic pyrazolones. Several of these analogues showed good oral bioavailability in rat and efficacy in the rat iodoacetate in vivo model.