8-(Heteroaryl)phenalkyl-1-Phenyl-1,3,8-triazaspiro[4.5]decan-4-ones as Opioid Receptor Modulators

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.

Towards a New Generation of Potential Antipsychotic Agents Combining D2 and 5-HT1A Receptor Activities

We report the discovery and the synthesis of novel, potential antipsychotic compounds combining potent dopamine D2 receptor antagonist and serotonin 5-HT1A receptor agonist properties in the same molecule. We describe the structure-activity relationship that lead us to the promising derivative: N-[(2,2-dimethyl-2,3-dihydro-benzofuran-7-yloxy)ethyl]-3-(cyclopent-1-enyl)-benzylamine 16. The latter has high affinity for D2 and 5-HT1A receptors, whereas it possesses only a weak affinity for 5-HT2A sites. In cellular models of signal transduction, 16 behaves as a silent antagonist at rD2 receptors while activating h5-HT1A receptors with an efficacy at least equivalent to that of the prototypical 5-HT1A agonist (+/-)-8-OH-DPAT. These dual actions confer a unique pharmacological profile to the product. In a behavioral model predictive of positive symptoms, 16 has an activity comparable to that of the typical antipsychotic haloperidol, while it is devoid of cataleptogenic effects. Although it produces behaviors characteristic of 5-HT1A receptor activation in rats, these occur at doses 100 times higher than those with (+/-)-8-OH-DPAT. We believe that the relative balance of D2 and 5-HT1A actions in 16 is appropriate, possibly optimal, to ensure superior efficacy and tolerability over existing antipychotic drugs.