Kal(SO4)2.12H2O: An efficient and reusable catalyst for the synthesis of quinolines, via Friedländer annulation, under solvent free conditions

Abstract

A mild, efficient and solvent free version of Friedländer annulation of 2-amino ketones and a-methylene carbonyl compounds for the synthesis of polysubstituted quinolines using alum (Kal(SO4)2.12H2O), as an inexpensive and reusable catalyst, in excellent yields is described. All the compounds are characterized by use of spectroscopic measurements (FT-IR, 1H NMR) and elemental analyses. This method provides several advantages such as mild reaction conditions, devoid of harsh reagents, simple work-up procedure, and is environment friendly.