The general procedure for the synthesis of 6-ethyl-3-aminopyridine from 5-nitro-2-vinylpyridine is as follows:[Ref. Example 66]; 5-Amino-2-ethylpyridine; 10% palladium-carbon catalyst (50% water moistened, 90 mg) was added to an ethanol solution (30 mL) of 5-nitro-2-vinylpyridine (450 mg), and the reaction was stirred under a hydrogen atmosphere at room temperature for 15 hours. Upon completion of the reaction, the catalyst was removed by filtration. Subsequently, the solvent was evaporated under reduced pressure to afford 6-ethyl-3-aminopyridine as an oily product (359 mg, 98% yield). The product was characterized by 1H-NMR (400 MHz, CDCl3): δ 1.25 (3H, t, J=7.5 Hz), 2.71 (2H, q, J=7.5 Hz), 3.32-3.78 (2H, br), 6.91-6.98 (2H, m), 8.02-8.05 (1H, m). Mass spectrum (ESI) m/z: 123 (M+H)+.
