P -Toluenesulfonic Acid Induced Conversion of Fluorinated Trimethylsilylethynylanilines into Aminoacetophenones: Versatile Precursors for the Synthesis of Benzoazaheterocycles

A simple and efficient approach to the synthesis of fluorinated amino-substituted acetophenones in good to excellent yields is reported. The heart of the proposed method consists of conversion of a Me ₃ Si-C≡C- moiety into a MeC(=O)- group in the presence of p -tolu ene sulfonic acid (p -TSA) passing a stage of ethynylaniline formation. The reaction is metal-free, proceeds under mild conditions, and uses readily available starting compounds (trimethylsilylarylacetylene derivatives). The reaction provides access to amino-substituted acetophenones, which may serve as precursors for the synthesis of polyfluorinated azaheterocycles, having potential anticarcinogenic activity.