Nitric Acid → 2-Hydroxy-5-nitro-3-(trifluoromethyl)pyridine

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Reaction Conditions

Reaction Steps

A mixture of 3-(trifluoromethyl)pyridin-2(1H)-one 2 (2.00 g, 12.26 mmol) and sulfuric acid (H2SO4, 3.5 ml, 30%) was heated to 90° C. and nitric acid (HNO3, 2.5 ml, 65%) was added. The mixture was stirred at 90° C. for 8 hours and additional nitric acid (1 ml, 65%) was added. The mixture was stirred for an additional 6 hours at 90° C. and was then poured into a beaker containing ice (30 ml). The mixture was diluted with water (30 ml) and 6N aqueous NaOH was added until a pH of about 4 to about 5. The mixture was extracted with ethyl acetate (3×40 ml), the combined organic phases dried over Na2SO4 and all solvents were removed under reduced pressure. The residue was dissolved in ethyl acetate and the product precipitated by the addition of hexane. After filtration, 5-nitro-3-(trifluoromethyl)pyridin-2(1H)-one 3 was obtained as a yellow powder (1.58 g, 7.59 mmol, 62%).

Provenance & Evidence