Bicyclo[4.2.0]octane-1,3,5-triene-7-ol

white powder

Bicyclo[4.2.0]octane-1,3,5-triene-7-ol (also known as 1-hydroxybenzocyclobutene) is a substituted benzocyclobutene compound. As an electron-donating group, it can be used in studies of polymerisation reactions. It serves as a starting material for the preparation of 1-methylbenzocyclobutene. 1-Methylbenzocyclobutene is a dielectric monomer characterised by excellent physical properties, chemical stability and high-temperature stability, and finds wide application in the electronics and microelectronics manufacturing industries.

The Journal of Organic Chemistry, 46, p. 2730, 1981 DOI: 10.1021/jo00326a026

Synthesis of bicyclo[4.2.0]octane-1,3,5-triene-7-ol: A solution of 1-acetoxybenzocyclobutene (33.9 g, 0.21 mol) and p-toluenesulfonic acid monohydrate (1.9 g, 0.01 mol) in methanol (100 mL) was stirred at room temperature for 24 h. Evaporate the solvent, add 50 mL of water, and extract three times with diethyl ether (150 mL). The ether solution was dried over magnesium sulphate, the solvent was evaporated, and recrystallisation yielded 21.4 g (85%) of bicyclo[4.2.0]octane-1,3,5-triene-7-ol (i.e. 1-hydroxybenzocyclobutene), a white powder^[1].

[1] Keisuke Chino, Takeshi E., Toshikazu Takata. (1997). Polymerization of o-Quinodimethanes Bearing Electron-Donating Groups in Situ Formed by Thermal Isomerization of Benzocyclobutenes. Macromolecules, 30 22, 6715–6720. https://doi.org/10.1021/ma9616928