Potassium Hydroxide → 4-Benzyloxy-6-methoxy-[1,5]naphthyridin-3-ol

Participants

Reaction Conditions

Reaction Steps

Tris(dibenzylideneacetone)dipalladium(0) (36 mg, 0.039 mmol, 0.02 eq) is added at room temperature to a stirred solution of 8-benzyloxy-7-bromo-2-methoxy-[1,5]naphthyridine (680 mg, 1.97 mmol, 1.0 eq) in water (10 mL), and dioxane (20 mL), followed by 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (47 mg, 0.099 mmol, 0.05 eq) and a solution of potassium hydroxide (220 mg, 3.94 mmol, 2.0 eq) in water (10 mL). After 6 hours stirring at 90° C., the reaction mixture is quenched with a 1N hydrochloric acid aqueous solution (4 mL) and extracted with ethyl acetate (3×10 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a residue that is purified by column chromatography (silica gel, eluent: petroleum ether:ethyl acetate, 4:1, v/v) to afford 4-benzyloxy-6-methoxy-[1,5]naphthyridin-3-ol as a light yellow solid (278 mg, 53% yield).

Provenance & Evidence