A selective small molecule NOP (ORL-1 receptor) partial agonist for the treatment of anxiety.

Small molecule (1) has been identified as a selective partial agonist of Opioid Receptor Like-1 (ORL-1) with potential utility for the treatment of anxiety and other disorders. Nociceptin (orphanin FQ) is an endogenous peptide ligand that binds to ORL-1, however it does not bind the classical δ, μ and κ opioid receptors with high affinity. The synthesis of 1 involved using a molecular diversity approach, to rapidly advance a library of compounds for biological testing. A lead selective potent partial agonist (35-fold ORL-1/Mu) progressed to ORL-1 (NOP or OP4) proof of concept testing in advanced studies. The synthetic approach and biological data for the related chemical series will be presented.