Synthesis of 4,5-dihydroxybenzocyclobutene-1,2-dione (a benzologue of squaric acid) and a general synthesis of benzocyclobutene-1,2-diones
Abstract
4,5-Dihydroxybenzocyclobutene-1,2-dione has been prepared by demethylation of its dimethyl ether which was made by vapour-phase pyrolysis of the anthracene adduct of 6,7-dimethoxyphthalazine-1,4-dione; other benzocyclobutene-1,2-diones have been made in 71–98% yield by this pyrolysis method.