Furan nitra with nitric acid in acetic anhydride, however, due to its poor aromaticity, is attacked by nucleophiles in the medium at its 5-position and requires a final stage of basic treatment or heating to restore aromaticity.

Stage 1. Generation of the electrophyte

Stage 2. Nucleophilic attack of furan on nitronium acetate

Step 3. Nucleophilic addition of acetate

Stage 4. Recovery of aromaticity