Nitric Acid → 4-Hydroxy-7,8-dimethyl-2H-1-benzopyran-2-one

Participants

Reaction Steps

Fuming nitric acid (13 ml) was added to a stirred suspension of 6,8-dimethyl-4-hydroxycoumarin (m.p. 253°- 255°; 2.21g) in chloroform (200 ml) at room temperature over 2 hours. After standing for a further 2 hours, the solvent was removed in vacuo at room temperature and 6N hydrochloric acid (50 ml) added to the residue. Filtration and recrystallisation from ethanol gave the product, m.p. 169.5°-170°(d), (C11H9NO5 requires C, 56.18; H, 3.86; N, 5.96. Found; C, 56.22; H, 3.99; N, 5.84).

Provenance & Evidence