Table 1.

UT-B inhibition activity^a and microsomal stability^b of synthesized compounds

Compd	R1	R2	IC50 (nM)	% Remainingb
1a			11	<5
1c			14	96
4a			38	22
4b			43	47
4c			353	14
4d			>800	79
4e			>800	75
4f			>800	24

^aDetermined by mouse erythrocyte lysis assay (n = 3). IC₅₀ determined by fit to a single-site saturation model.

^bPercentage of parent compound remaining after 30 min incubation with rat liver microsomes.