US Patent 6869960 N-substituted spiropiperidine compounds as ligands for ORL-1 receptor

A compound of the formula:or a pharmaceutically acceptable salt, ester or ether thereof, wherein R1 through R12 are independently hydrogen or the like; X1 and X2 are independently CH2 or the like; R13 is hydrogen or the like; or R12 and R13 taken together with three ring atoms of the quinoline ring separating said substituents form a heterocyclic ring; R14 and R15 are hydrogen or the like or these groups taken together form oxo; and the dotted line represents a single or double bond. These compounds are ligands for ORL-1 receptor and especially are antagonists for said receptor.