Nitric Acid → 6-Ethyl-4-hydroxy-3-nitro-2H-1-benzopyran-2-one

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Reaction Steps

Fuming nitric acid (33 ml) was added to a stirred suspension of 6-ethyl-4-hydroxycoumarin (m.p. 216°-8°; 5.52g) in chloroform (500 ml) at room temperature over 1 hour. After standing for a further hour, the solvent was removed in vacuo at room temperature and 6N hydrochloric acid (100 ml) added to the residue. Filtration gave the product m.p. 114°-5°, (C11H9NO5 requires C, 56.17; H, 3.86 N, 5.96. Found: C, 55.86; H, 3.80; N, 5.86). Recrystallisation from benzene-petroleum ether (b.p. 40°-60°) raised the melting point to 117°-9°.

Provenance & Evidence