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A. A solution of [1,8]naphthyridine (0.2 mmol) and potassium amide (0.8 mmol) in liquid ammonia (20 mL) is stirred at -40 C. for 3 h. The solution is concentrated. Residue is partitioned between EtOAc and water. EtOAc layer is separated and washed successively with water and brine. EtOAc layer is dried over sodium sulfate, filtered and concentrated to give [1,8]naphthyridin-2-ylamine which is used as is for the next step.