Selectivity of C- Versus O-acylation of diphenols by clay catalysts. I. Acylation of resorcinol with phenylacetyl chloride

Resorcinol was acylated by phenylacetyl chloride with a set of catalysts consisting of the montmorillonite-based K-series and their cation-exchanged forms. The selectivity of C-acylation over O-acylation could be significantly increased by an appropriate ion exchange and by a solvent-free reaction mode, resulting in a 60% preparative yield of 1-(2,4-dihydroxyphenyl)-2-phenyl-ethanone.