The present invention relates compounds of the formula (I): wherein ring A is
a phenyl or pyridyl ring; X represents a linker selected from the group consisting
of: (a), (b), (c), (d), (e), (f), (g), (h), (i), (j), (k), (l) and R1,
R2, R3, R4, R5, R6, R7,
R13, R14, R15, R16, R?17, R18,
R19, R21a and R21b are as defined herein. The
compounds are of particular use in the treatment or prevention of depression, anxiety,
pain, inflammation, migraine, emesis or postherpetic neuralgia.
##STR1##
##STR2##
