THE SYNTHESIS OF [H-3] L-734,217, AN ORALLY-ACTIVE FIBRINOGEN RECEPTOR ANTAGONIST

The synthesis of [H-3]L-734,217, 1b, an orally active fibrinogen recep tor antagonist, is described. The conversion of 3-amino crotonate 6 to [H-3]L-734,217 was carried out via a two step sequence of catalytic t ritiation followed by basic hydrolysis. Deuterium model reactions show ed that the reduction of 6 with PtO2 occurred via hydrogen transfer fr om the solvent (ethanol or acetic acid) leading to poor isotope incorp oration. When this reduction was conducted in methanol with 10% Pd/C, good isotope incorporation resulted. Ultimately, [H-3]L-734,217 was fo rmed with a specific activity of 42 Ci/mmol.