General procedure for the synthesis of 2-methyl-6-hydrazinopyridine from 2-chloro-6-methylpyridine: [0719] A mixture of 2-chloro-6-methylpyridine (5 g, 39.19 mmol) with an excess of hydrazine hydrate (20 g, 391.94 mmol) was reacted by refluxing the reaction for 36 hours at 119°C. Upon completion of the reaction, unreacted hydrazine hydrate was removed by concentration under reduced pressure. The residue was diluted with deionized water (30 ml) and extracted with dichloromethane (30 ml x 3). The organic layers were combined, washed with saturated saline (30 ml), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The crude product was purified by recrystallization from petroleum ether (15 ml) at -10 °C to afford 2-methyl-6-hydrazinopyridine (2.40 g, yield: 49.35%) as a black-brown solid.1H NMR (400 MHz, DMSO-d6) δ 7.39-7.29 (m, 1H), 7.25 (s, 1H), 6.51 (d, J = 8.4 Hz. 1H), 6.39 (d, J = 7.3 Hz, 1H), 4.06 (s, 2H), 2.26 (s, 3H).MS (ESI) m/z (M + H) + 127.8.
