To a solution of 2,4-dichloro-6-methoxypyrimidine (5.0 g, 28.0 mmol) and tert-butyl piperidin-4-ylcarbamate (5.6 g, 28.0 mmol) in DMF (50 mL) was added K2CO3 (7.74 g, 56.0 mmol) and the mixture was stirred at RT for 6 h. The reaction was quenched with water and the suspension was filtered, washed with water and dried. The crude was purified with silica gel chromatography (eluting with 20% EtOAc in petroleum ether) to give tert-butyl (1-(4-chloro-6-methoxypyrimidin-2-yl)piperidin-4-yl)carbamate 276a (6.0 g, 73% yield). MS (ESI, pos. ion) m/z: 342.8 (M+1); 1H-NMR (400 MHz, CDCl3): δ ppm 5.97 (s, 1H), 4.64 (d, 2 H, J=13.2 Hz), 4.49 (brs, 1H), 3.88 (s, 3H), 3.04 (t, 2 H, J=11.6 Hz), 2.03 (d, 2 H, J=10.4 Hz), 1.57 (s, 3H), 1.46 (s, 9H). And tert-butyl (1-(2-chloro-6-methoxypyrimidin-4-yl)piperidin-4-yl)carbamate 276b (1.0 g, 12% yield). MS (ESI, pos. ion) m/z: 343.1 (M+1); 1H-NMR (400 MHz, CDCl3): δ ppm 5.70 (s, 1H), 4.49 (brs, 1H), 4.22 (d, 2 H, J=12.4 Hz), 3.91 (s, 3H), 2.96-3.00 (m, 2H), 2.03 (d, 2 H, J=8.4 Hz), 1.45 (s, 9H), 1.3-1.39 (m, 2H).
