Potent and selective bicyclic lactam inhibitors of thrombin. Part 4: transition state inhibitors.

Bicyclic piperazinone based thrombin inhibitors of general structure 2 were prepared and evaluated in vitro and in vivo. These inhibitors, having in common an electrophilic basic trans-cyclohexylamine P1 residue, displayed high thrombin affinity, high selectivity against trypsin and good in vivo efficacy in the rat arterial thrombosis model.