COPPER(II)-CATALYZED MOLECULAR-REARRANGEMENTS - THE BEHAVIOR OF ARYLHYDRAZONES OF SOME 3-BENZOYLAZOLES IN THE PRESENCE OF COPPER(II) ACETATE

The reactivity of arylhydrazones of some 3-benzoylazoles (1,2,4-oxadia zole, isoxazole and 1,2,5-oxadiazole) induced by copper(II) catalysis has been investigated. In the 1,2,4-oxadiazole and isoxazole systems, copper(II) acetate monohydrate in methanol effectively induces molecul ar rearrangements of the arylhydrazones into the corresponding 1,2,3-t riazoles, that is, without competitive oxidation processes. In the 1,2 ,5-oxadiazole series, no ring transformation occurs by the action of t he same salt, the expected rearrangement into triazole oximes being ac hieved rather with sodium ethoxide in ethanol.