75833-48-6Relevant academic research and scientific papers
Practical Multigram Syntheses of Benzocyclobutenediones
South, Michael S.,Liebeskind, Lanny S.
, p. 3815 - 3821 (2007/10/02)
Experimentally simple syntheses of benzocyclobutenedione and substituted benzocyclobutenediones (3-OH; 4-OH; 4-Me; 3-OH, 5-Me) are described which allow the synthesis of these compounds on large scale from inexpensive starting materials.The regiospecific and stereoselective cycloaddition of trimethylsiloxy dienes to 1,4-dichloro-3,3,4-trifluorocyclobutene forms the basis of the synthesis of the substituted benzocyclobutenediones.
Benzocyclobutenes. Part 5. Synthesis of 4-Hydroxy-, 4,5-Dihydroxy-, and 3,6-Dihydroxy-benzocyclobutene-1,2-dione (Benzologues of Semisquaric and Squaric Acid)
Abou-Teim, Omar,Jansen, Robert B.,McOmie, John F. W.,Perry, David H.
, p. 1841 - 1846 (2007/10/02)
4-Methoxy- and 4,5-dimethoxy-benzocyclobutene-1,2-dione have been made by flash vacuum pyrolysis of the anthracene adducts of the corresponding phthalazine-1,4-diones which were prepared from the appropriate methoxyphthalic anhydrides. 3,6-Dimethoxybenzocyclobutene-1,2-dione has been prepared from 2-amino-3,6-dimethoxybenzoic acid via the addition of 3,6-dimethoxybenzyne to vinylidene chloride followed by hydrolysis of the resulting 1,1-dichloro-3,6-dimethoxybenzocyclobutene, bromination, and further hydrolysis.The three methoxy-diones and 4,5-dimethoxyphthalaldehyde have been demethylated by heating them with hydrobromic acid and the pKa values of the four hydroxy-compounds have been measured.Preliminary experiments on the synthesis of 4,5-dimethoxybenzocyclobutene are recorded.
