887625-09-4

947248-50-2

887625-09-4

Step E. N-(6-chloroimidazo[1,2-b]pyridazin-2-yl)-2,2,2-trifluoroacetamide (80 mg, 0.30 mmol) was dissolved in a mixed solvent of THF, methanol, and water (1 mL each), and anhydrous potassium carbonate (400 mg, 3 mmol) was added. The reaction mixture was heated to reflux for 8 hours. After completion of the reaction, it was cooled to room temperature and diluted with ethyl acetate and water. The organic and aqueous phases were separated, and the organic layer was washed with saturated saline (2 x 5 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford 2-amino-6-chloroimidazo[1,2-b]pyridazine (45 mg, 90% yield). The product was characterized by 1H NMR (DMSO-d6, 300 MHz): δ 5.65 (s, 2H), 7.02 (d, 1H), 7.7 (d, 1H).