| abstract |
A compound of formula: (See formula I) or a salt, ester or pharmaceutically acceptable ether therein, in which R1 to R12 are independently hydrogen or the like; X1 and X2 are independently CH2 or the like; R13 is hydrogen or the like; or R12 to R13 taken together with three ring atoms quinoline ring separating the said substituents form a heterocyclic ring; R14 and R15 are hydrogen or the like, or these groups taken together form an oxo group; and the dashed line represents a single or double bond. These compounds are ligands for the ORL-1 receptor and especially are antagonists of said receptor. |