General procedure for the synthesis of 6-methyl-2-formylpyrazine from (6-methylpyrazin-2-yl)methanol: to a solution of (6-methylpyrazin-2-yl)methanol (1.50 g, 12.1 mmol) in dichloromethane (30 mL) at -15°C was added Dess-Martin periodinane (7.70 g, 18.1 mmol) . The reaction mixture was stirred at -15°C for 3 h. The reaction was quenched by the addition of water (50 mL) and extracted with ethyl acetate (3 x 50 mL). The combined organic layers were washed with brine (60 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography (ethyl acetate-petroleum ether, 1:9) to afford 6-methyl-2-formylpyrazine (540 mg, 36% yield) as a yellow solid.1H NMR (300 MHz, DMSO-d6) δ 10.02 (s, 1H), 8.91 (s, 1H), 8.82 (s, 1H), 2.61 (s, 3H).
