General procedure for the synthesis of 2-chloro-6-fluoro-3-methoxyaniline from 2-chloro-6-fluoro-3-methoxybenzoic acid: To a mixture of dichloromethane (20 mL) and N,N-dimethylformamide (3 drops), a solution of 2-chloro-6-fluoro-3-methoxylbenzoic acid (2.7 g, 13.2 mmol, 1.0 equiv.) was added drop-wise at 0 °C and oxalyl chloride ( 5.0 g, 39.6 mmol, 3.0 equiv). The reaction mixture was stirred at room temperature for 1 h and then concentrated to dryness. The residue was dissolved in acetone (20 mL) and added dropwise to a solution of sodium azide (2.6 g, 39.6 mmol, 3.0 equiv) in water (15 mL) at 0 °C. The reaction was stirred at 0 °C for 1 h. Water (50 mL) was added and the reaction mixture was then heated at 70 °C overnight. The acetone was removed by distillation and the aqueous residue was extracted with ethyl acetate. The combined organic extracts were washed with water and brine, dried over anhydrous sodium sulfate, filtered and evaporated in vacuum to give the residue. The residue was purified by column chromatography (ethyl acetate: petroleum ether, 0:1 to 1:30) to give the title compound as a yellow oil (0.85 g, 37%).LC-MS: m/z 176.0, 178.0 [M + H]+.
