Catalyst-free Friedel–Crafts hydroxyalkylation of imidazo[1,2-α]pyridines with ethyl trifluoropyruvate†
Abstract
A catalyst free Friedel–Crafts (F–C) hydroxyalkylation of imidazo[1,2-α]pyridines with ethyl trifluoropyruvate is herein described using isopropyl ether as a solvent. Electron-donating and electron-withdrawing functional groups at various aromatic positions were well tolerated under our optimized conditions. The method enabled the generation of desired products in moderate to excellent yields under mild conditions, which makes this transformation an attractive, environmentally benign alternative for the synthesis of the target compounds.