Sulfuric Acid → HCID 15334806, compound

Participants

Reaction Steps

A solution of 6,8-dihydro-α-isopropyl-α,1-dimethyl-6,8-dioxobenzo[2,1-b:3,4-c']dipyrrole-7(1H)acetonitrile (5.30 g, 18.0 mmol) in methylene chloride is added dropwise to concentrated sulfuric acid at 5°-10° C. with rapid stirring. The ice bath is removed and the reaction mixture is stirred overnight at ambient temperatures, poured over crushed ice, diluted with methylene chloride, treated with 50% sodium hydroxide solution with ice bath cooling to pH 3-4 and separated. The aqueous layer is extracted with methylene chloride. The combined organic layers are dried (MgSO4) and concentrated in vacuo to give an orange foam residue, which is recrystallized from methylene chloride to afford the title product as yellow crystals (1.30 g, 23.2%), mp 184°-189° C.

Provenance & Evidence