Synthesis
GENERAL STEPS: To a solution of 4-bromopyridine-2-carbonitrile (20 g, 109.29 mmol) in 1,4-dioxane (300 mL) was added sequentially Pd(OAc)2 (2.98 g, 13.27 mmol), XPhos (18.9 g, 39.34 mmol) and Cs2CO3 (50.3 g, 154.38 mmol). The reaction mixture was stirred at 100 °C for 1 hour. After completion of the reaction, the mixture was cooled to room temperature and solid impurities were removed by filtration. The filtrate was concentrated under reduced pressure and purified by fast column chromatography (eluent: EtOAc/petroleum ether = 1/3, v/v) to afford the target compound tert-butyl (2-cyanopyridin-4-yl)carbamate as a yellow solid (23 g, 95% yield).LC-MS (ES, m/z): 220 [M + H]+. 1H NMR (300 MHz, CDCl3) : δ 8.49 (d, J = 5.6 Hz, 1H), 7.87 (d, J = 2.2 Hz, 1H), 7.43 (dd, J = 5.6, 2.2 Hz, 1H), 6.90 (s, 1H), 1.54 (s, 9H) ppm.
