Exploration of 4,4-disubstituted pyrrolidine-1,2-dicarboxamides as potent, orally active Factor Xa inhibitors with extended duration of action

Abstract Aiming to improve upon previously disclosed Factor Xa inhibitors, a series of 4,4-disubstituted pyrrolidine-1,2-dicarboxamides were explored with the intent of increasing the projected human half-life versus 5 (projected human t 1/2  = 6 h). A stereospecific route to compounds containing a 4-aryl-4-hydroxypyrrolidine scaffold was developed, resulting in several compounds that demonstrated an increase in the half-life as well as an increase in the in vitro potency compared to 5 . Reported herein is the discovery of 26 , containing a (2 R ,4 S )-4-hydroxy-4-(2,4-difluorophenyl)-pyrrolidine scaffold, which is a selective, orally bioavailable, efficacious Factor Xa inhibitor that appears suitable for a once-daily dosing (projected human t 1/2  = 23 h).