8-acenaphthen-1-yl-1-phenyl-1,3,8-triaza-spiro[4.5]decan-4-one derivativesas orphanin FQ receptor agonists

A series of 8-acenaphthen-1-yl-1-phenyl-1,3,8-triaza-spiro[4.5]decan-4-one derivatives 1 was studied with respect to the binding affinity for the orph anin FQ (OFQ) and opioid (mu, kappa, delta) receptors. The influence of ste reochemistry as well as the substitution pattern of the phenyl-ring in posi tion 1 on the affinity for the orphanin FQ receptor and selectivity to opio id (mu, kappa, delta) receptors is discussed. The most interesting compound Ic was tested for its anxiolytic-like properties in vivo. (C) 1999 Elsevie r Science Ltd. All rights reserved.