The ETA receptor antagonist (2) (N-(3,4-dimethyl-5-isoxazolyl)-4'-(2-oxazolyl)-[1,1'-biphenyl]-2-sulfonamide, BMS-193884) shares the same biphenyl core as a large number of AT, receptor antagonists, including irbesartan (3). Thus, it was hypothesized that merging the structural elements of 2 with those of the biphenyl AT, antagonists (e.g., irbesartan) would yield a compound with dual activity for both receptors. This strategy led to the design, synthesis, and discovery of (15) 4'- [(2-butyl-4-oxo-1,3-diazaspiro[4.4]non- 1-en-3-yl)methyl]-N-(3,4-dimethyl-5-isoxazolyl)-2'-[(3,3-dimethyl-2-oxo-1-pyrrolidinyl-methyl]-[1,1'-biphenyl]-2-sulfonamide, BMS248360) as a potent and orally active dual antagonist of both AT, and ETA receptors. Compound 15 represents a new approach to treating hypertension.