合成路线1

The N-protected dipeptide (I) is coupled to 4-(aminomethyl)benzonitrile (II) by means of EDC to afford amide (III). Acidic cleavage of the N-Boc group of (III) yields the deprotected amine (IV), which is then condensed with sulfamoyl chloride, producing sulfamide (V). From this, the target amidine can be obtained in two ways. Addition of hydrogen sulfide to the cyano group of (V), followed by S-alkylation with iodomethane, gives rise to the thioimidate (VI), which is then displaced with ammonium acetate to provide the desired amidine. Alternatively, addition of hydroxylamine to nitrile (V) leads to the amidoxime (VII) which, upon catalytic hydrogenation, is converted into the title amidine.