Compounds of formula (I)
##STR1##
wherein n1 is 0, 1, or 2; n2 is 0, 1, or 2; X is a bond, O, S, or NR1;
and Ar1 is a 5-membered aromatic ring, 6-membered aromatic ring, or
a fused bicycloheterocycle. The compounds are useful in treating conditions or
disorders prevented by or ameliorated by 7 nAChR ligands. Also disclosed
are pharmaceutical compositions having compounds of formula (I) and methods for
using such compounds and compositions.
