4-Fluoro-3-methoxyaniline

454-16-0

64465-53-8

General procedure for the synthesis of 4-fluoro-3-methoxyaniline from 2-fluoro-5-nitroanisole: 1. Reduction of nitro: The nitro compound 2-fluoro-5-nitroanisole (6.5 g, 0.038 mol) and iron powder (10.6 g, 0.19 mol) were suspended in ethanol (90 ml) and heated to 50 °C. Concentrated hydrochloric acid (120 ml) was added dropwise to the reaction mixture at 0°C. The reaction mixture was stirred at 20°C for 18 hours. 2. Post-treatment: the reaction mixture was filtered through diatomaceous earth and the filter cake was washed repeatedly with ethanol. The filtrate and washings were combined and concentrated under reduced pressure to remove ethanol. The residue was alkalized to pH neutral with solid Na2CO3. 3. Extraction and purification: Extract the alkalized aqueous phase with ethyl acetate and combine the organic phases. The organic phase was washed with water and saturated saline in turn, and then dried with anhydrous Na2SO4. The drier was removed by filtration, and the organic phase was concentrated under reduced pressure to obtain 4-fluoro-3-methoxyaniline (5g, 93% yield). Product characterization: HPLC-MS showed a purity of 97% and a molecular ion peak (M+1) of 142.1.