Synthesis of novel triplet drugs with 1,3,5-trioxazatriquinane skeletons and their pharmacologies. 1: Synthesis of triplet drugs with morphinan skeletons.

We synthesized symmetrical and nonsymmetrical triplet drugs with 1,3,5-trioxazatriquinane skeletons. The isolation of key intermediates, oxazoline dimers, made it possible to effectively produce nonsymmetrical triplets. Among the synthesized triplets, KNT-93, composed of three identical opioid μ receptor agonists, showed dose-dependent antinociception via the μ receptor. The effect was 56-fold more potent than that of morphine, a representative μ agonist. The profound analgesic effect induced by KNT-93 might result from simultaneous occupation of three μ opioid receptors.