A Short Synthesis of the Factor-Xa Inhibitor DX-9065a using palladium-catalyzed key steps

We describe a new, efficient synthesis of DX‐9065a (4), a potent inhibitor of the blood coagulation enzyme factor Xa (fXa) which has previously been prepared in more than 20 steps. We saved approximately 10 steps starting with a Pd‐catalyzed cyanation of the triflate 10 of 7‐methoxynaphthalen‐2‐ol (9). After cleavage of the MeO group with boron tribromide, the triflate 6 was coupled to acrylate 5 in a Heck reaction (→3). The subsequent transformations led to DX‐9065 a.