Oxidation with metal oxides-VI: oxidation of benzoylhydrazones of aldehydes, ketones and 1,2-diketones with nickel peroxide

Abstract

Benzaldehyde benzoylhydrazone on oxidation with nickel peroxide gives a mixture of 2,5-diphenyl-1,3,4-oxadiazole and nickel-bis-benzaldehyde benzoylhydrazone. Similarly, p-tolualdehyde benzoylhydrazone, o-methoxybenzaldehyde benzoylhydrazone and anisaldehyde benzoylhydrazone give the corresponding 1,3,4-oxadiazole derivatives and nickel complexes. Acetophenone benzoylhydrazone on the other hand, gives a mixture of acetophenone and methylbenzylidene-∞-dibenzoyl-amino-∞-methylbenzylamine. Similarly, propiophenone benzoylhydrazone and benzophenone benzoylhydrazone give the corresponding ketones and Schiff's bases. Biacetyl bisbenzoylhydrazone and benzil bisbenzoylhydrazone on oxidation with nickel peroxide in chloroform give the corresponding enol-benzoates and nickel complexes. In contrast, phenylmethylglyoxal bisbenzoylhydrazone gives only the enolbenzoate under analogous conditions. Phenylglyoxal bisbenzoylhydrazone on oxidation with nickel peroxide gives a mixture of products consisting of 1-dibenzoylamino-4-phenyl-1,2,3-triazole, 1-benzoylamino-4-phenyl-1,2,3-triazole and nickel-bis-phenyl-2-(5-phenyl-1,3,4-oxadiazolyl)-ketone benzoylhydrazone. Similarly, 4-methoxyphenylglyoxal bisbenzoylhydrazone gives a mixture of triazoles and the corresponding nickel complex.