Novel, potent and selective chimeric FXa inhibitors featuring hydrophobic P1-ketoamide moieties.

Judicious combination of P-region sequences of highly potent anticoagulant proteins including NAP5, NAP6, Ecotin, and Antistasin with SAR from small molecule FXa inhibitors led to a series of chimeric inhibitors of formula 1a-j. We report herein the design, synthesis, and biological activity of this novel family of FXa inhibitors that express both high in vitro potency and superb selectivity against related serine proteases.