General procedure for the synthesis of 2-methylaminopyrimidine from 2-cyanopyrimidine: To a stirred solution of 2-cyanopyrimidine (10) (0.2 g, 0.9 mmol) in ethanol (1 mL) was added 10% palladium/carbon (20 mg) under a nitrogen atmosphere. The reaction mixture was stirred under hydrogen atmosphere (using a balloon to maintain atmospheric pressure) for 12 h. Upon completion of the reaction, it was filtered through a diatomaceous earth pad. The filtrate was concentrated under reduced pressure to give the crude product. The crude product was purified by neutral alumina column chromatography (eluent: ethyl acetate/hexane = 1:1) to afford 2-methylaminopyrimidine (24) (0.19 g, 95% yield). Thin layer chromatography (TLC) conditions: 50% ethyl acetate/hexane (Rf: 0.1). 1H NMR (400 MHz, CDCl3): δ 8.70 (d, J=5.2 Hz, 2H), 7.16 (t, J=4.8 Hz, 1H), 4.19 (s, 1H), 4.11-4.08 (m, 1H).
