19828-20-7

Step 4 Synthesis of 1-(6-aminopyridin-3-yl)ethanone: To a 1L autoclave was added a saturated aqueous ammonia solution (750 mL) of 1-(6-chloropyridin-3-yl)ethanone (40 g, 257.10 mmol). The reaction mixture was stirred at 130°C for 10 hours. After completion of the reaction, the mixture was cooled and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent ratio 50:1 dichloromethane/methanol) to afford the target compound 1-(6-aminopyridin-3-yl)ethanone in a yield of 33 g in 89% yield as a yellow solid.

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