Sulfuric Acid → Cyclopenta[c]thiophene-4,6-dione

Participants

Reaction Steps

In a dry 3-neck flask with an argon inlet and a water condenser, diethyl thiophene-3,4-dicarboxylate (3.7 g, 16.2 mmol) is mixed with sodium ethoxide (1.1 g, 16.2 mmol). After heating to 100° C. ethyl acetate (1.4 g, 16.2 mmol) is added through syringe pump over one hour. The mixture was further heated for a few hours. The residue was redissolved in water at 70° C. and concentrated sulfuric acid is added (1 mL). The mixture is heated at this temperature for one hour to ensure complete decarboxylation.

Provenance & Evidence