Nitric Acid → 2,4-Difluoro-5-nitrobenzoic acid

Participants

Reaction Steps

2,4-Difluorobenzoic acid (5 g, 0.031 M) was dissolved in concentrated sulfuric acid (30 ml), and cooled to 0°. The mixture was stirred, and fuming nitric acid (d 1.567 g/ml, 1.91 ml, 0.047 M) added dropwise, keeping the temperature below 5°. After stirring for 3 hours, the mix was poured onto ice, and organics extracted into dichloromethane (2×75 ml). The combined organic layers were washed with water, dried (MgSO4), and evaporated to give 2,4-difluoro-5-nitrobenzoic acid (3.9 g, 61%). Nmr (DMSO-d6): δ 7.18 (t, 1H); 8.88 (t, 1H); 9.93 (br, 1H).

Provenance & Evidence