Nitric Acid → N-(3-Fluoro-4-nitrophenyl)acetamide

Participants

Reaction Steps

Added 3′-fluoroacetanilide (3.06 g, 20 mmol) cautiously to concentrated sulfuric acid (6 mL) at 5° C. To the resulting solution, added fuming nitric acid (1.05 mL, 25 mmol) dropwise while maintaining temperature at 5–10° C. After 30 min, added ice (50 g), later diluted with water (100 mL) and extracted with EtOAc (2×100 mL). The combined organic layers were washed with saturated NaHCO3 and brine, dried over anhydrous Na2SO4 and concentrated to give the crude product (4.0 g) as a mixture of isomers (1:1.4 ratio of 4′-nitro/2′-nitro). The desired isomer, 3′-flouro-4′-nitroacetanilide, was isolated by flash chromatography (DCM-5% MeOH/DCM) in low yield (1.2 g, 30%) as a yellow solid. 1H-NMR (CDCl3): δ 8.08 (1H, app t), 7.82 (1H, dd), 7.41 (1H, br s), 7.21 (1H, m), 2.25 (3H, s).

Provenance & Evidence