We have been exploring the potential of 5-HT2B antagonists as a therapy for chronic heart failure. To assess the potential of this therapeutic approach, we sought compounds possessing the following attributes:(a) potent and selective antagonism of the 5-HT2B receptor,(b) low impact of serum proteins on potency, and (c) desirable pharmacokinetic properties. This Letter describes our investigation of a biphenyl benzimidazole class of ...