2,6-Diaminopyridine → 2-Amino-1,8-naphthyridine

Participants

Reaction Conditions

Reaction Steps

Pyridine-2,6-diamine (0.30 g, 2.8 mmol), 3-dimethylaminoacrolein (90%, 0.30 g, 2.8 mmol), and polyphosphoric acid (PPA) (2.7 mL) were combined and the reaction mixture was heated to 120° C. for 10 hours. Then, the reaction mixture was poured on ice water and neutralized with solid sodium carbonate. The resulting aqueous mixture was extracted three times with ethyl acetate and the combined organic extracts were washed with brine, concentrated, and purified by column chromatography (EtOAc/hexanes) to give [1,8]-naphthyridin-2-ylamine Yield 85 mg (21%). LCMS (ESI): calc. C8H7N3=145; obs. M+H=146.

Provenance & Evidence