Mitsunobu coupling between boronic acid (I) and 3-bromo-2,5-dichlorothiophene (II) affords the thienyl isophthalate (III). Partial hydrolysis of diester (III) using methanolic KOH gives rise to mono-acid (IV), which is further condensed with N,N-dimethyl ethylenediamine (V) to provide the amide-ester (VI). Displacement of the methyl ester function of (VI) by guanidine (VII) then produces the target acyl guanidine, which is finally converted into the corresponding dihydrochloride salt.