Compounds of formula (I) 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 α7 nAChR ligands. Also disclosed are pharmaceutical compositions having compounds of formula (I) and methods for using such compounds and compositions.