Novel 3,4,7-Substituted Benzofuran Derivatives Having Binding Affinity to κ-Opioid Receptor

: A series of novel 3,4,7-trisubstituted benzofuran derivatives were synthesized, and their binding affinity to κ- (KOR) and μ-opioid receptors (MOR) were evaluated. Several aryl ethers showed moderate binding activities to KOR (IC50=3.9-11 µM) without binding to MOR.