171178-45-3

Step a: To a solution of dichloromethane (200 mL) containing 6-chloropyridin-3-amine (30.0 g, 0.23 mol), DMAP (1 g), and Et3N (41.7 g, 0.47 mol) was slowly added Boc2O (54.5 g, 0.25 mol) at 0 °C. The reaction mixture was gradually warmed to room temperature and stirred overnight. Upon completion of the reaction, the reaction mixture was washed with saturated NaHCO3 solution. The aqueous phase was extracted with dichloromethane and the combined organic phases were washed with brine (100 mL) and dried over anhydrous Na2SO4. Concentration of the organic phase under reduced pressure afforded tert-butyl 6-chloropyridin-3-ylcarbamate (50.0 g, 94% yield), the product was used directly for the next reaction without further purification.1H NMR (300 MHz, CDCl3) δ 8.23 (d, J=2.7 Hz, 1H), 7.97 (d, J=6.9 Hz, 1H), 7.27-7.24 (m, 1H), 6.58 (m, 1H), 7.25 (m, 1H), 6.25 (m, 1H), 6.25 (m, 1H). 1H), 6.58 (s, 1H), 1.52 (s, 9H).

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