General procedure for the synthesis of methyl 2-(4-methoxy-3-nitrophenyl)acetate from methyl 2-(4-hydroxy-3-nitrophenyl)acetate and iodomethane: To a solution of methyl 2-(4-hydroxy-3-nitrophenyl)acetate (4.87 g, 23.1 mmol) was added K2CO3 (8 g, 58 mmol) at room temperature, followed by slow addition of CH3I ( 6.6 g, 46.5 mmol). The reaction mixture was stirred at room temperature overnight. After the reaction was completed, the mixture was poured into ice water (100 mL) and extracted with CH2Cl2 (3 x 300 mL). The organic layers were combined, washed with brine, dried over Na2SO4, filtered and concentrated to give methyl 2-(4-methoxy-3-nitrophenyl)acetate (5 g, 96% yield) as a yellow solid.LCMS analysis showed an [M + H]+ of 226.0; retention time (Rt) of 1.438 min.
