A series of 4-[(2-{isobutyl [(5-methyl-2-furyl) sulfonyl] amino} phenoxy) methyl] benzoic acids and 4-({2-[isobutyl (1, 3-thiazol-2-ylsulfonyl) amino] phenoxy} methyl) benzoic acids were synthesized and evaluated for their EP receptor affinities and EP1 receptor antagonist activities. Further structural optimization was carried out to reduce inhibitory activity against hepatic cytochrome P450 isozymes, which could represent a harmful potential drug ...