合成路线1

The condensation of dimethyl 5-aminoisophthalate (I) with 2,5-dimethoxytetrahydrofuran (II) in refluxing AcOH provided the pyrrolyl derivative (III). Partial hydrolysis of (III) with methanolic KOH then gave mono ester (IV). After activation of the carboxy group of (IV) as the corresponding mixed anhydride with isobutyl chloroformate, reduction employing NaBH4 furnished alcohol (V). The ester group of (V) was then displaced with guanidine-HCl (VI) in the presence of NaOMe to yield the title benzoyl guanidine, which was isolated as the methanesulfonate salt.