[Synthesis of N-alpha-(tosylglycylprolyl)-4-amidinophenylalanine amides as thrombin inhibitors].

N alpha-(Tosylprolylglycyl)-4-cyanphenylalanine was synthesized by the reaction of an activated ester and a mixed anhydride, respectively, of Tos-Pro-Gly-OH with 4-cyanophenylalanine. N alpha-(Tosylglycylprolyl)-4-cyanophenylalanine was prepared by reaction of Tos-Gly-Cl with N alpha-prolyl-4-cyanophenylalanine. These acids were transferred into the amides. The cyano compounds were converted into the desired amidines via the thioamides and the thioimidic esters.