3-Cyanobenzaldehyde oxime (I) was treated with N-chlorosuccinimide to afford hydroxyiminoyl chloride (II). Subsequent cycloaddition of the intermediate nitrile oxide, generated in situ from (II) and Et3N, with methyl methoxyacrylate (III) produced isoxazole (IV). Then, basic hydrolysis of the ester group, followed by treatment with SOCl2 provided acid chloride (V). Aminobiphenyl (VIII) was obtained by Suzuki coupling of 4-bromoaniline (VI) with boronic acid (VII) using a palladium catalyst. Condensation of (VIII) with acid chloride (V) in the presence of Et3N then gave amide (IX). Alternatively, amide (IX) was obtained by AlMe3-catalyzed condensation of ester (IV) with amine (VIII). Treatment of nitrile (IX) with HCl in MeOH-CHCl3 generated the corresponding iminoester (X) with concomitant cleavage of the N-tert-butyl group. Finally, reaction of this iminoester with methanolic ammonium carbonate afforded the target amidine.

The reaction of 3-formylbenzonitrile (I) with methyl 2-bromoacetate (II) by means of activated Zn in hot THF gives 3-(3-cyanophenyl)-3-hydroxypropionic acid methyl ester (III), which is oxidized with activated MnO2 in hot dichloromethane yielding the oxoester (IV). The bromination of (IV) with NBS in CCl4 affords the alpha bromo derivative (V), which is cyclized with thioacetamide (VI) in hot THF affording 4-(3-cyanophenyl)-2-methylthiazole-5-carboxylic acid methyl ester (VII). The condensation of (VII) with 4'-amino-N-tert-butylbiphenyl-2-sulfonamide (VIII) by means of trimethylaluminum in toluene/dichloromethane gives the corresponding amide (IX), which is treated with hot TFA to eliminate the ter-butyl protecting group yielding intermediate (X). Finally, the cyano group of (X) is treated first with anhydrous HCl in methanol, and finally with ammonium carbonate in the same solvent to obtain the target amidine.