Synthesis of a novel 6,14-epoxymorphinan derivative and its pharmacology

A novel 6,14-epoxymorphinan benzamide derivative (NS22) was synthesized, which showed opioid κ receptor agonistic activity in the [35S]GTPγS binding assay. The antinociceptive effect of NS22 was evaluated in the tail-flick and the hot-plate test. This compound showed a potent antinociceptive activity in mice by sc administration, which was attenuated with nor-BNI (selective opioid κ receptor antagonist).