[Synthesis]
2-Cyclopropyl-5-nitropyridine (300 mg, 2.24 mmol) was used as starting material and mixed with 10% palladium/carbon catalyst (32 mg) in ethanol (15 mL). The reaction mixture was stirred overnight at room temperature under hydrogen atmosphere. Upon completion of the reaction, the catalyst was removed by filtration through a diatomaceous earth pad and the filtrate was concentrated to obtain the crude product. To improve the conversion, the crude product was reacted again under the same hydrogenation conditions and separated as described previously. Finally, the crude product was purified by preparative HPLC (high pH buffer) to afford the target compound 6-cyclopropylpyridin-3-amine as an orange oil (30 mg, 12% yield). The structure of the product was confirmed by 1H NMR (400 MHz, chloroform-d): δ 0.85-1.06 (m, 4H), 1.98-2.09 (m, 1H), 3.78-4.07 (m, 2H), 6.93 (d, J = 7.79 Hz, 1H), 7.01 (dd, J = 8.24, 2.75 Hz, 1H), 8.06 (d, J = 3.21 Hz, 1H); mass spectrum (ES+APCI+): m/z 135 [M+H]+. |