The synthesis and the structure of N-isopropyl-N'-[2-(3'-methylphenylamino)-5-nitrobenzenesulfonyl] urea (14) was drawn from two thromboxaneA2receptorantagonists structurally related to torasemide. Compound 14 showed an IC50 value of 22 nM for the thromboxaneA2 (TXA2) receptor of human washed platelets. Compound 14 prevented platelet aggregation induced by arachidonic acid (0.6 mM) and U-46619