GENERAL METHOD: 2-amino-5-bromopyridine (1 mmol) and cyclopropylboronic acid (1.3 mmol) were dissolved in toluene (10 mL) under argon protection. Subsequently, anhydrous K3PO4 (3 mmol) and water (1 mL) were added and the reaction mixture was stirred under argon atmosphere for 10 min. Next, tricyclohexylphosphine (10 mol%) and Pd(OAc)2 (5 mol%) were added and the reaction mixture was stirred at 37 °C. The reaction was refluxed until GC-MS analysis showed complete consumption of the feedstock. Upon completion of the reaction, the mixture was cooled to room temperature, filtered through a diatomaceous earth pad, diluted with ethyl acetate (25 mL), washed with water (3 x 20 mL), dried over anhydrous Na2SO4, and concentrated to dryness under reduced pressure. The crude product was purified by silica gel column chromatography using a solvent mixture of methanol and dichloromethane as eluent. 2-Amino-5-cyclopropylpyridine (1a) was obtained in 85% yield. Thin layer chromatography (TLC) Rf = 0.26 (methanol:dichloromethane = 1:19).1H NMR (400 MHz, CDCl3) δ 7.89 (d, J = 2.4 Hz, 1H), 7.11 (dd, J = 8.4, 2.4 Hz, 1H), 6.42 (d, J = 8.4 Hz, 1H), 4.19 (s, 2H), 1.80- 1.73 (m, 1H), 0.93-0.81 (m, 2H), 0.62-0.51 (m, 2H).13C NMR (100 MHz, CDCl3) δ 156.4, 146.2, 135.6, 129.0, 108.4, 12.2, 7.5. GC-MS: retention time tR = 6.724 min (m/z (relative)). abundance) 134 (64.41%)).
