The Lead Tetraacetate Oxidation of Aromatic Compounds

The reactions of lead tetraacetate with alkylaromatic compounds, acetophenone, halobenzenes, biphenyl, and anisole have been investigated. Controlled lead tetraacetate oxidation of alkylaromatic compounds offers a new method for the synthesis of substituted benzyl acetates. Acetophenone reacted at 120°C to give phenacyl acetate and phenacylidene acetate, the former being higher in yield. But neither nuclear acetoxylated nor nuclear methylated products were detected. Both chloro-benzene and bromobenzene gave nuclear acetoxylated products, the isomer distributions being, for chlorobenzene : o-, 85; m-, 5; p-, 10; and for bromobenzene: o-, 54; m-, 16; p-, 30%. Biphenyl reacted only at the reflux temperature to give acetoxybiphenyl. Anisole gave guaiacol acetate at 120°C, neither the m- and p-isomers nor the methylated products being detected.