2-Nitro-4-aminophenol (10.0 g, 64.9 mmol) was used as starting material and mixed with cesium carbonate (21 g, 64 mmol) and iodomethane (9.22 g, 64.9 mmol) in acetonitrile (1500 mL). The reaction mixture was heated to reflux for 5 hours. After completion of the reaction, the mixture was cooled to room temperature and filtered to remove insoluble solids. The filtrate was concentrated under reduced pressure to remove the solvent, and the resulting crude product was purified by fast column chromatography (eluent: chloroform) to give 5.03 g of 4-methoxy-3-nitroaniline in 46% yield as a red oil. The structure of the product was confirmed by 1H NMR (DMSO-d6) δ 7.09-7.03 (m, 2H), 6.87 (d, J=3Hz, 1H), 5.21 (bs, 2H), 3.77 (s, 3H) and HRMS (EI) m/z 168.0497 (M+1). Elemental analysis results (C7H8N2O3): calculated values C 50.00, H 4.80, N 16.66; measured values C 50.20, H 5.07, N 16.60.
