Nitric Acid → 2,3,4-Trifluoro-5-nitrobenzoic acid

Participants

Reaction Steps

A 3 liter three neck round bottom flask is charged with 125 ml H2SO4. Fuming nitric acid is added (8.4 ml, 199 mmol) and the mixture gently stirred. 2,3,4-Trifluorobenzoic acid 1 (25 g, 142 mmol) is added in 5 g portions over 90 minutes. The dark brownish yellow solution is stirred for 60 min at which time the reaction is complete. The reaction mixture is poured into 1 liter of an ice:water mixture and extracted with diethyl ether (3×600 ml). The combined organic extracts are dried (MgSO4) and concentrated under reduced pressure to give a yellow solid. The solid is suspended in hexanes and stirred for 30 min after which time it is filtered to give 29 g (92%) of clean desired product as an off-yellow solid: MS APCI (−) m/z 220 (M-1) detected.

Provenance & Evidence