Sulfuric Acid → 2,3-Difluoro-6-nitrophenol

Participants

Reaction Conditions

Reaction Steps

1.77 kg (10 mol) of 2,3,4-trifluoronitrobenzene are added to 4 l of water. The mixture is then warmed to 40° C. and vigorously stirred. 389.4 g (22 mol) of 31.7% strength potassium hydroxide solution are then added dropwise in such a way that the temperature remains between 40° and 55° C. After about 4 h, the reaction is complete (GC checking). The reaction mixture is brought to pH 3 using 70% strength sulfuric acid at 70° C. Steam is then passed into the solution, the product passing over with it and being isolated after cooling to 10° C. 1.51 kg of 2,3-difluoro-6-nitrophenol having a purity >99.9% (GC) are obtained after drying (melting point 63.5° C.), which corresponds to a yield of 86% of theory.

Provenance & Evidence