The electrophilic substitution of benzocyclobutene—I : Nitration, acetylation and hydrobromination

Abstract

Nitration, Friedel-Crafts acetylation and hydrobromination of benzocyclobutene result in extensive displacement of a methylene group by the reagent giving o-substituted β-phenethyl and polystyrene derivatives. Where ring opening does not occur substitution is mainly at the 4-position and only to a negligible extent at the 3-position. The product proportions obtained from the acetylation are highly dependent on temperature and on the solvent used. The results are discussed in terms of solvation and strain effects.