Sulfuric Acid → HCID 53827548, compound

Participants

Reaction Steps

Concentrated sulfuric acid (5.50 mL) is added slowly to a solution of 3,6-dihydro-a-isopropyl-a,6-dimethyl-1,3-dioxobenzo[1,2-b:3,4-c']dipyrrole-2(1H)-acetonitrile (5.50 g, 19.0 mmol) in methylene chloride at 10° C. Crushed ice is added. The mixture is stirred for 24 hours at ambient temperature and poured onto crushed ice, treated with 6N sodium hydroxide to pH 2, and extracted with methylene chloride. The organic layer is separated, dried (MgSO4) and concentrated in vacuo to give an orange foamy residue. Flash chromatography (silica gel, ether then ethyl acetate eluents) affords the title product as a yellow foam (1.53 g, 25.7%), mp 159°-168° C.

Provenance & Evidence