[Synthesis of N alpha-(4-methylbenzoyl)-4-amidinophenyl-alaninamides and -esters]

To test their inhibitory activity against serine proteinases, especially thrombin, in comparison to the very potent N alpha-tosyl-4-amidinophenylalaninamides, the authors synthetized the compounds named in the title, which contain the p-toluoyl residue in place of the tosyl residue. These compounds were prepared from 4-cyanophenyl-alanine (1) by N-acylation to 2 and formation of the active ester 3 which was aminolyzed. The amides thus obtained were converted, via the thioamides and the thioimidic acid ester salts, to the amidine hydroiodides 16-19. The methyl ester 21 was afforded from 2 by means of the Pinner reaction.