PROCESS FOR THE PRODUCTION OF ACYLATED IMIDAZOLES AND PYRAZOLES

摘要

Acylated imidazoles and pyrazoles of the formula I and II in which R<2> and R<3> can be identical or different and denote, independently of one another, H, alkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl radicals, R<4> denotes H, alkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl radicals and R<5> denotes alkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, aryl, aralkyl, alkylaryl or carboxyl radicals, are prepared by converting five-membered heteroaromatics of the formula III or IV in which R<1> - R<3> can be identical or different and, independently of one another denote H, alkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl radicals, at least one of the radicals R<1> - R<3> being hydrogen, and R<4> denotes H, alkyl having 1 to 12 carbon atoms, alkenyl having 1 to 12 carbon atoms, aryl, aralkyl or alkylaryl radicals, with acylating agents of the formula V in which R<5> has the abovementioned meaning and Y denotes a halide, alkoxy, acyloxy, hydroxyl, amido or carboxyl radical, in the presence of zeolites as catalysts. Preferably, zeolites of the pentasil type are used as catalysts.