AD-8717 was obtained as shown in Scheme 24060801a. The condensation of 2-mercaptonicotinic acid (I) with 2,4-dimethoxybenzyl alcohol (II) by means of HCl in acetone yields 2-[(2,4-dimethoxybenzyl)thio]nicotinic acid (III). The reaction of (III) with oxalyl chloride in dioxane yields the corresponding chloride, which is condensed with 4-amino-2,6-dimethylpyridine N-oxide (IV) by means of triethylamine in tetrahydrofuran affording 4-[2-[(2,4-dimethoxybenzyl)thio]nicotinoylamino]-2,6-dimethylpyridine N-oxide (V). The reduction of (V) with phosphorus trichloride in dichloromethane yields 2-[(2,4-dimethoxybenzyl)thio]-N-(2,6-dimethyl-4-pyridyl)nicotinamide (VI), which is finally oxidized with m-chloroperbenzoic acid in dichloromethane.

AD-8717 was obtained as shown in Scheme 24060801a. The condensation of 2-mercaptonicotinic acid (I) with 2,4-dimethoxybenzyl alcohol (II) by means of HCl in acetone yields 2-[(2,4-dimethoxybenzyl)thio]nicotinic acid (III). The reaction of (III) with oxalyl chloride in dioxane yields the corresponding chloride, which is condensed with 4-amino-2,6-dimethylpyridine N-oxide (IV) by means of triethylamine in tetrahydrofuran affording 4-[2-[(2,4-dimethoxybenzyl)thio]nicotinoylamino]-2,6-dimethylpyridine N-oxide (V). The reduction of (V) with phosphorus trichloride in dichloromethane yields 2-[(2,4-dimethoxybenzyl)thio]-N-(2,6-dimethyl-4-pyridyl)nicotinamide (VI), which is finally oxidized with m-chloroperbenzoic acid in dichloromethane.