Acylation of 5-amino-2,4,6-triiodoisophthaloyl chloride (I) with 2-isopropyl-1,3-dioxane-5-carbonyl chloride (II) provided the amido isophthaloyl chloride (III). Acid chloride (III) was then condensed with 3-(methylamino)-1,2-propanediol (IV) to furnish the triamide compound (V). The acetal protecting group was finally removed under acidic conditions.