A compound of the formula:or a pharmaceutically acceptable salt thereof, wherein R is unsubstituted, mono-, di- or tri-substituted (C3-C11)cycloalkyl or (C3-C11)cycloalkenyl or the like, A is unsubstituted (C1-C7)
alkyl or (C2-C5 )alkenyl, or unsubstituted, mono-, di- or tri-substituted
aryl, or aromatic-heterocyclic or the like, Y is
hydrogen, halo, amino or mercapto, or unsubstituted, mono-, di- or tri- substituted (C1-C10)
alkyl-M-, (C3-C7)cycloalkyl-M-, (C2-C6)alkenyl-M-, (C1-C4)
alkyl-NH-((C1-C4)alkyl)-M-, di(C1-C4)alkyl-N-((C1-C4)alkyl)-M-,
aryl-M-, aromatic or non-aromatic heterocyclic-M-,
aryl-(C1-C5)alkyl-M- or aromatic non-aromatic heterocyclic-(C1-C5)alkyl-M-, wherein M is a
covalent bond O, S, NH or the like, or the like; Z1, Z2, Z3 and Z4 are
hydrogen or the like, has ORL1-
receptor agonist activity, and are useful as analgesics or the like in mammalian subjects.