4-Fluorobenzoic Acid → 4-Fluoro-3-nitrobenzoic acid

Participants

Reaction Steps

To a cold solution of 4-fluorobenzoic acid (50.0 g, 0.36 mol, 1.0 equiv) in concentrated H2SO4 (180 ml) was added portionwise potassium nitrate (39.7 g, 0.39 mol, 1.1 equiv). The reaction mixture was stirred overnight at rt and then poured on crushed ice (800 g) with constant stirring. The resulting mixture was kept overnight at rt, filtered and washed thoroughly with water, and finally dried by making an azeotrope with toluene to yield 59.5 g (90%) of the title compound as a light yellow solid. 1H NMR (400 MHz, DMSO): δ7.69-7.74 (m, 1H), 8.29-8.32 (m, 1H), 8.56 (d, J=7.2 Hz, 1H), 13.75 (br s, 1H).

Provenance & Evidence