Ammonium Chloride → 3-Amino-6-fluoro-2-phenylaminobenzoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a mixture of 6-fluoro-3-nitro-2-phenylaminobenzoic acid methyl ester (2.1 g, 7.24 mmol) in a mixture of MeOH (50 mL) and water (15 mL) were added NH4Cl (2.23 g, 43.4 mmol) and iron powder (1.61 g, 28.9 mmol) and the reaction mixture heated at 90° C. for 3 h. After cooling to RT, the suspension was filtered through a pad of Celite® washing with additional MeOH. The filtrate was concentrated in vacuo to remove the organic solvent and the resulting aqueous residue extracted with EtOAc (×3). The combined organic fractions were washed with brine, dried (MgSO4) and concentrated in vacuo to afford the title compound as an orange oil which solidified on standing (2.0 g, quantitative). 1H NMR (CDCl3, 400 MHz): δ 7.23-7.18 (2H, m), 7.13 (1H, br s), 6.89-6.80 (3H, m), 6.69-6.64 (2H, m), 3.83 (3H, s)

Provenance & Evidence