Synthesis
The general procedure for the synthesis of 2-hydrazino-5-methylpyridine from 2-chloro-5-methylpyridine was as follows: 5.7 mL (5.9 g, 117.6 mmol) of hydrazine hydrate was added to 1.0 g (7.8 mmol) of 2-chloro-5-methylpyridine, and the reaction mixture was refluxed and stirred for 16 hr at a temperature of 150 °C oil bath. Upon completion of the reaction, it was cooled to room temperature and the reaction mixture was subsequently concentrated on a rotary evaporator. The residue was co-evaporated with 10 mL of ethylene glycol monoethyl ether and the process was repeated three times. The final residue was dissolved in dichloromethane, the precipitate was separated by filtration and the filtrate was concentrated under reduced pressure to give the target product. Yield: 644 mg (67% yield). The product was analyzed by LC-MS (Method 6): retention time (Rt) = 0.35 min; mass spectrum (ESI positive ion mode): m/z = 124 [M + H]+.
References
[1] Patent: US2010/93803, 2010, A1. Location in patent: Page/Page column 21
[2] Patent: US2010/305085, 2010, A1. Location in patent: Page/Page column 21
[3] ChemMedChem, 2018, vol. 13, # 10, p. 988 - 1003
[4] Bioorganic and Medicinal Chemistry Letters, 2013, vol. 23, # 6, p. 1743 - 1747
