2-(Trifluoromethylsulfonyloxy)pyridine as a Reagent for the Ketone Synthesis from Carboxylic Acids and Aromatic Hydrocarbons

Article abstract of DOI:10.1246/bcsj.61.455

A new reagent 2-(trifluoromethylsulfonyloxy)pyridine (TFOP) was prepared by the reaction of sodium salt of 2-pyridinol with trifluoromethylsulfonyl chloride in dioxane.The conpound TFOP in trifluoroacetic acid has been found to intermolecularly dehydrate from benzoic acid and aromatic hydrocarbons to give the corresponding benzophenones in high yield.It was further elucidated, in the reaction of fluorene, that a variety of carboxylic acids can be used as the acyl precursor for the aromatic ketone synthesis in conjunction with the TFOP/TFA system.This acylation procedure has been applied to the synthesis of 2-acylthiophenes, which are hard to prepare in a satisfactory yield by the classical Friedel-Crafts reaction using aluminum chloride as the catalyst.