Preparation of indene derivatives

摘要

A process for preparing indene derivatives of the general formula I where R1 is a C1-C10-alkyl radical, a phenyl radical or a C1-C4-alkyl-substituted phenyl radical and A is a bridge which, together with the adjacent carbons, forms a six-membered aromatic or a five- or six-membered heteroaromatic or carbocyclic ring onto which a further aromatic ring may be fused, comprises reacting II with III (X=chlorine, bromine, iodine) in the presence of a Friedel-Crafts catalyst to give IV which is then dehydrogenated to I.