Example 54B Synthesis of methyl 2-bromo-4-nitrobenzoate: 2-bromo-4-nitrobenzoic acid (1.0 g, 4.06 mmol) and potassium carbonate (560 mg) were dissolved in N,N-dimethylformamide (5 mL), followed by the addition of iodomethane (500 μL, 8.03 mmol). The reaction mixture was stirred at room temperature for 1 hour. After completion of the reaction, the mixture was poured into water (30 mL) and extracted with ether (3 x 10 mL). The combined ether layers were washed sequentially with water (1 × 10 mL) and brine (1 × 10 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to afford the target product methyl 2-bromo-4-nitrobenzoate (970 mg, 92% yield). The product was confirmed by 1H NMR (300 MHz, CDCl3): δ 8.52 (d, 1H, J=2.4 Hz), 8.21 (dd, 1H, J=2.0,8.5 Hz), 7.92 (d, 1H, J=8.8 Hz), 3.99 (s, 3H); the mass spectrum (ESI) showed m/z=259 (M-H).
