Synthesis of (((Benzenesulfonamido)alkyl)phenyl)alkanoic Acid Derivatives Containing Pyridyl or Imidazolyl Groups and Their Thromboxane A2 Receptor Antagonistic and Thromboxane A2 Synthase Inhibitory Activities.

As part of our search for a dual inhibitor possessing both thromboxane A2 (TXA2) receptor antagonistic and TXA2 synthase inhibitory activities, some [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives possessing a pyridyl or imidazolyl group were synthesized. Their TXA2 receptor antagonistic and TXA2 synthase inhibitory activities were evaluated in terms of the inhibitory effects on U-44619-induced guinea-pig platelet aggregation and on thromboxane B2 (TXB2) production in human platelets, respectively. It was found that 3-[4-[2-(1-imidazolyl)-1-(4-chlorobenzenesulfonamido)ethyl]phenyl]propionic acid (22a), containing an imidazolyl group, is a well-balanced dual inhibitor having both TXA2 receptor antagonistic activity (IC50=0.31μM) and TXA2 synthase inhibitory activity (IC50=0.39μM).