Potassium Nitrate → 6-Trifluoromethyl-7-nitro-1,4-dihydro-2,3-quinoxalinedione

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Reaction Conditions

Reaction Steps

The title compound was prepared using an adaptation of the method of Cheeseman (Cheeseman, G. W. H., J. Chem. Soc. 1171 (1962)). 6-Trifluoromethyl-1,4-dihydro-2,3-quinoxalinedione (200 mg, 0.869 mmol) was dissolved in 8 mL of concentrated H2SO4 and the yellow-green solution was cooled to 0° C. with stirring. To this was added in small portions KNO3 (87.8 mg, 1.10 mmol). The reaction was allowed to stir 1 h at 0° C. and then was allowed to come to room temperature and stir overnight. The brown-orange reaction mixture was then poured into 10 mL ice H2O. The product was isolated by vacuum filtration as pale yellow crystals which were rinsed with a small amount of cold H2O and air dried. The crystals were further dried under vacuum (0.1 torr, 25° C.) to yield 121.1 mg (50.6% yield). 1H NMR (d6 -DMSO) δ7.53 (s, 1H, ArH), 7.80 (s, 1H, ArH), 12.4 (s, 2H, NH). EIMS m/z 275 (81, M+), 217 (36), 201 (100, bp), EIHRMS calc. for C9H4N3O4F3 275.0153, found 275.0170.

Provenance & Evidence