The design of low molecular weight thrombin inhibitors IIa-d (hirutonins) that bind concurrently with the enzyme's catalytic site and auxiliary'anion-binding exosite" for fibrinogen recognition is reported. A practical synthesis of the required homologous ketomethylene arginyl dipeptide inserts [Arg $ L! O (CH,), CO](n= 1-4) corresponding to the P1-Pi scissile position of htonjna is described. The subetitution of the de amide function by ...
