Solid-phase bromination of hindered phenols

Abstract

The solid-Phase bromination of a series oftert-butyl-substituted phenols withN-bromosuccinimide and dioxane dibromide afforded halogenated cyclohexadienones, quinobromides. Under the extrusion conditions, the latter underwent further transformations, mainly, debromination. A new reaction, dioxane dibromide catalyzed anhydroheterocyclization of 2,2′-dihydroxy-3,3′,5,5′-tetra-tert-butyldiphenyl to 2,4,6,8-tetra-tert-butyldibenzofuran, was discovered and the mechanism of this reaction was proposed.