A. Synthesis of ethyl 3-methyl-4-nitrobenzoate. A mixture of 3-methyl-4-nitrobenzoic acid (362.3 g, 2.0 mol), N,N-dimethylformamide (200 mL), sodium bicarbonate (200 g, 2.38 mol), and ethyl iodide (623.9 g, 4.0 mol) was stirred for 18 hr. at 70 °C. Upon completion of the reaction, the mixture was cooled to room temperature and poured into water (2000 mL). The resulting solid product was collected by filtration, washed with water and dried. Subsequently, the solid was further washed with hexane and dried to afford the title compound ethyl 3-methyl-4-nitrobenzoate (382.1 g, 91% yield) as an off-white solid with a melting point of 51-52.5°C. The structure of the product was confirmed by 1H NMR (CDCl3) and mass spectrometry (NH3-Cl):1H NMR (CDCl3) δ 8.04-7.98 (m, 3H 3H), 4.42 (q, 2H), 2.63 (s, 3H), 1.42 (t, 3H); mass spectrum (NH3-Cl) m/z 210 (100%, M+H+).
