a) Synthesis of 2-amino-4-methylbenzonitrile
4-Methyl-2-nitrobenzonitrile (4.9 g, 30 mmol) was mixed with 10% palladium-carbon catalyst (500 mg) in 1,4-dioxane (60 mL), and the reaction was stirred overnight under a hydrogen atmosphere (balloon pressurized). Upon completion of the reaction, the catalyst was removed by diatomaceous earth filtration and the filtrate was concentrated under reduced pressure to give the crude product. The crude product was further purified by fast column chromatography (eluent: dichloromethane) to afford 2-amino-4-methylbenzonitrile as a light yellow solid (3.3 g, 83% yield).
1H-NMR (300 MHz, CDCl3) δ 7.26 (d, J = 8.3 Hz, 1H), 6.56 (s, 1H), 6.55 (s, 1H), 4.32 (br s, 2H), 2.29 (s, 3H).
