Synthesis and structure activity relationship studies of benzothieno[3,2-b]furan derivatives as a novel class of IKKβ inhibitors

Abstract

As a novel class of IKKβ inhibitors, a series of tricyclic furan derivatives was designed and synthesized based on the structure of known thiophene IKKβ inhibitors. Among the various fused furan derivatives synthesized, a benzothieno[3,2-b]furan derivative 13a displayed potent inhibitory activity towards IKKβ in enzymatic and cellular assays. The potent inhibitory activity originates from an intramolecular non-bonded S⋯O interaction which was confirmed by the X-ray structure of JNK3 with 16k. The introduction of further substituents on the core structure led to the discovery of the 6-alkoxy derivatives, which possessed a comparable IKKβ inhibitory activity to 13a and an improved metabolic stability. Among these, appropriately lipophilic compounds 16a, h, i, and 13g (logD>2) were found to possess good oral bioavailability. © 2007 Pharmaceutical Society of Japan.