HFIP-mediated strategy towards β-oxo amides and subsequent Friedel-Craft type cyclization to 2 quinolinones using recyclable catalyst

A simple and cost-effective 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-mediated protocol for the synthesis of p-oxo amides has been described by using amines and p-keto esters as substrates. The reaction conditions were found to be highly efficient towards the cleavage of C-O bond and consequent formation of the products in excellent yields and selectivity. The obtained beta-oxo amides were further transformed in to the synthetically useful 2 quinolinones via intramolecular Friedel-Craft type cyclization of aromatic ring using ferrites as a recyclable catalyst. A spectrum of substrates bearing broad range of functional groups were well tolerated under the reaction conditions. The proposed mechanistic pathways were substantially verified by literature and mass-spectroscopic evidences. (C) 2020 Elsevier Ltd. All rights reserved.