Process for the preparation of alkenyl aromatics

摘要

The application relates to a process for the preparation of alkenyl aromatics such as <IMAGE> in which R<1> can denote straight-chain or branched alkyl radicals having 1 to 12 carbon atoms or cycloalkyl radicals having 5 to 8 carbon atoms or aryl radicals, in which R<2> and R<3> are identical or different and can denote hydrogen or radicals as mentioned under R<1>, and in which R<4> represents hydrogen, hydrocarbon radicals as in R<1>, alkenyl radicals having 2 to 12 carbon atoms, alkoxy radicals having 1 to 12 carbon atoms, aryloxy radicals having 6 to 12 carbon atoms, the formyl radical, acyl radicals having 2 to 12 carbon atoms, acetal radicals having 3 to 12 carbon atoms, ester radicals having 2 to 12 carbon atoms, the cyano radical, halogen or a haloalkyl radical having 1 to 5 carbon atoms, for example -CF3, -CCl3, -CH2CF3, in which process alcohols are split off from alkoxyalkyl aromatics of the formula (II) <IMAGE> in which R<1> to R<4> have the abovementioned meaning and R<5> represents straight-chain or branched alkyl radicals, in the presence of zeolites and/or phosphates which have a zeolite structure as catalysts.