New azole antagonists with high affinity for the P2Y1 receptor

Five-membered-ring heterocyclic urea mimics have been found to be potent and selective antagonists of the P2Y1 receptor. SAR of the various heterocyclic replacements is presented, as well as side-chain SAR of the more potent thiadiazole ring system leading to thiadiazole 4c as a novel antiplatelet agent.