Selective preparation of polycyclic aromatic hydrocarbons. Part 4.1 New synthetic route to anthracenes from diphenylmethanes using Friedel–Crafts intramolecular cyclization

Abstract

Preparation of several anthracenes from diphenylmethanes by direct Bradsher-type reaction, which incorporates formylation of a hydrocarbon followed by Friedel–Crafts intramolecular cyclization, is presented. The present method involving the action of Cl₂CHOMe and TiCl₄ on a variety of diphenylmethanes (constructed such that electrophilic substitution occurs ortho to the biphenyl linkage) offers a convenient, mild, one-pot synthesis of substituted anthracenes.