Nitric Acid → 2H-3,1-Benzoxazine-2,4(1H)-dione, 6-nitro-

Participants

Reaction Conditions

Reaction Steps

Isatoic Anhydride (25.0 g, 153.25 mmol) is suspended in acetic acid (50 mL) with efficient stirring. The reaction vessel is placed in a pre-heated oil bath at 40° C. and red fuming nitric acid (99.5%, 75 mL, 1.67 mol) is added over 35 minutes (Caution: Exothermic). The reaction mixture is stirred for an additional 4 hours at 38-44° C., then cooled to 20° C. using an ice bath. The reaction mixture is poured on ice (400 mL). After the ice melts, the yellow solid is isolated by vacuum filtration and washed with cold water (5×100 mL). The yellow solid is dried under high vacuum to constant weight at 60-70° C. affording 27.92 g (87%) of product; 1H-NMR (300 MHz, DMSO-d6); δ12.33 (s, 1H), 8.58 (d, J=2.5 Hz, 1H), 8.53 (dd, J=2.6 Hz, 9.0 Hz, 1H), 7.31 (d, J=8.9 Hz, 1H).

Provenance & Evidence