The use of sulfonylamido pyrimidines incorporating an unsaturated side chain as endothelin receptor antagonists

A series of compounds structurally related to bosentan 1 featuring an unsaturated side chain at position 6 of the core pyrimidine have been studied for their potential to block the ETA and ETB receptor. Incorporation of a 2-butyne-1,4-diol linker bearing a pyridyl carbamoyl moiety led to in vitro highly potent endothelin receptor antagonists (e.g., 70 and 75). The propargyl derivative 26 significantly reduced blood pressure in in vivo model studies with hypertensive salt-sensitive Dahl rats.