Oxidation of bis‐aroylhydrazones of 3,3‐dimethylpentane‐2,4‐dione and thermal decomposition of the oxidation products

Abstract

Abstract Oxidation of the title bis‐aroylhydrazones 2 with lead tetraacetate gives l‐aroyl‐5‐aroylazo‐3, 4, 4, 5‐tetramethyl‐2‐pyrazolines 6 in good yields. The aroylazopyrazolines 6 decompose by refluxing in chloroform or ethanol solution to l‐aroyl‐5‐hydroxy‐3, 4, 4, 5‐tetramethyl‐2‐pyrazolines 3 , l‐aroyl‐5‐methylene‐3, 4, 4‐trimethyl‐2‐pyrazoles 10 and 1‐aroyl‐3, 4, 4, 5‐tetramethyl‐2‐pyrazolines 11 . The spectral data of the prepared compounds, as well as the reaction mechanisms are discussed.