33207-59-9Relevant academic research and scientific papers
2-(Trifluoromethylsulfonyloxy)pyridine as a Reagent for the Ketone Synthesis from Carboxylic Acids and Aromatic Hydrocarbons
Keumi, Takashi,Yoshimura, Kiichiro,Shimada, Masakazu,Kitajima, Hidehiko
, p. 455 - 460 (2007/10/02)
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.
N-Acylimidazoles-Trifluoroacetic Acid System as the Acylating Agent for Aromatic Hydrocarbons
Keumi, Takashi,Saga, Hiroshi,Kitajima, Hidehiko
, p. 1638 - 1641 (2007/10/02)
N-Benzoylimidazole in trifluoroacetic acid could benzoylate electron-rich aromatic compounds, such as durene, p-dimethoxybenzene, mesitylene, anisole, thiophene, and fluorene, to give the corresponding benzophenone derivatives in good yields.It was further elucidated, in the reaction of fluorene, that N-acylimidazoles composed of a variety of acyl groups also could be used for the ketone synthesis.Therein, the imidazolides of aliphatic carboxylic acids or substituted benzoic acid with an electron-donating group gave ketones in high yields.The above-mentioned aromaticcompounds were also acylated with N-trifluoroacetylimidazole and free carboxylic acids in trifluoroacetic acid.The mechanism for these reactions was assumed to proceed via a mixed anhydride between trifluoroacetic acid.
