Step 2 - Synthesis of 5-bromo-2-methyl-3-nitropyridine
Diethyl 2-(5-bromo-3-nitropyridin-2-yl)malonate (1.2 g, 3.3 mmol) was dissolved in 7.0 N HCl (10 mL). The mixture was heated to reflux for 5 hours. After completion of the reaction, it was cooled to room temperature and extracted with dichloromethane: methanol (10:1, v/v). The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by column chromatography using petroleum ether: ethyl acetate (4:1, v/v) as eluent to afford 5-bromo-2-methyl-3-nitropyridine (0.7 g, yield: 89.7%).
1H-NMR (CDCl3, 400 MHz) δ 8.76 (s, 1H), 8.40 (s, 1H), 2.80 (s, 3H).
