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

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Reaction Steps

1.77 kg (10 mol) of 2,3,4-trifluoronitrobenzene and 1.56 kg (21-mol) of calcium hydroxide are heated to 70° C. in 5 l of water and the mixture is well stirred. The reaction is finished after about 6 h, as can be detected by gas chromatography. The mixture is acidified to pH 1.5 with 70% strength sulfuric acid and worked up as described in Examples 1 and 2 (the alkaline solution can also be filtered from inorganic salts at 60° C. before acidification). 1.40 kg of yellow 2,3-difluoro-6-nitrophenol are isolated; a residual content of 2,3-difluoro-4-nitrophenol cannot be detected. The yield corresponds to 80% of theory.

Provenance & Evidence