Nitric Acid → 6-Amino-5-methyl-1,3-benzoxazol-2(3H)-one

Participants

Reaction Conditions

Reaction Steps

5-Methyl-3H-benzoxazol-2-one (1.10 g, 7.38 mmol) added to stirring Nitric acid (6.00 mL, 143 mmol). After stirring 1 h, the mixture was heated at 50° C. for 4 h, cooled and then poured into 100 mL ice and allowed to stand overnight to melt. The yellow solids were collected by filtration, washing with water. The crude nitro product was hydrogenated (25 psi) over 10% Palladium on Carbon (50% Wet) (0.240 g, 0.113 mmol) in Methanol (30.0 mL) for 3 h. The mixture was filtered through Celite and rinsed with MeOH (50 mL). After conc. in vacuo, 6-Amino-5-methyl-3H-benzoxazol-2-one (0.765 g; Yield=63.2%) was isolated as an off-white solid.

Provenance & Evidence