1-[3-Aminobenzisoxazol-5′-yl]-3-trifluoromethyl-6-[2′-(3-( R)-hydroxy- N-pyrrolidinyl)methyl-[1,1′]-biphen-4-yl]-1,4,5,6-tetrahydropyrazolo-[3,4- c]-pyridin-7-one (BMS-740808) a highly potent, selective, efficacious, and orally bioavailable inhibitor of blood coagulation factor Xa

Efforts to further optimize the pyrazole factor Xa inhibitors by masking the aryl aniline P4 moiety resulted in a novel bicyclic tetrahydropyrazolo-pyridinone scaffold. Optimization of this series resulted in the identification of BMS-740808 ( 6f), a highly potent and selective orally bioavailable inhibitor of blood coagulation factor Xa. Attempts to further optimize the pyrazole factor Xa inhibitors centered on masking the aryl aniline P4 moiety. Scaffold optimization resulted in the identification of a novel bicyclic pyrazolo-pyridinone scaffold which retained fXa potency. The novel bicyclic scaffold preserved all binding interactions observed with the monocyclic counterpart and importantly the carboxamido moiety was integrated within the scaffold making it less susceptible to hydrolysis. These efforts led to the identification of 1-[3-aminobenzisoxazol-5′-yl]-3-trifluoromethyl-6-[2′-(3-( R)-hydroxy- N-pyrrolidinyl)methyl-[1,1′]-biphen-4-yl]-1,4,5,6-tetrahydropyrazolo-[3,4- c]-pyridin-7-one 6f (BMS-740808), a highly potent (fXa K i = 30 pM) with a rapid onset of inhibition (2.7 × 10 7 M −1 s −1) in vitro, selective (>1000-fold over other proteases), efficacious in the AVShunt thrombosis model, and orally bioavailable inhibitor of blood coagulation factor Xa.