Hydrochloric Acid → 4-Amino-2,3-difluoro-5-nitrobenzoic acid

Participants

Reaction Steps

Ammonium hydroxide solution (˜30% in water) (35 ml, 271 mmol) is added to a solution of 2,3,4-trifluoro-5-nitro-benzoic acid 2 (15 g, 67.8 mmol) in 30 ml water at 0° C. with stirring. Upon completion of ammonium hydroxide addition the reaction mixture is warmed to room temperature with stirring. After 2.5 h, the reaction mixture is cooled to 0° C. and concentrated HCl is carefully added until pH of reaction mixture is near 0. The reaction mixture is diluted with water (30 ml) and extracted with diethyl ether (3×50 ml). The combined organic extracts are dried (MgSO4) and concentrated under reduced pressure to give 14 g (95%) of pure desired product: MS APCI (−) m/z 217 (M-1) detected.

Provenance & Evidence