Quinolins are important heterocyclic systems, constituting the structure of many naturally occurring products with interesting pharmacological properties. Among the various synthetic methods in quinoline synthesis, Frienlander condensation is an extremely useful and versatile method for the direct construction of a quinoline ring. Herein, we report the first application of metaborosulfuric acid as an efficient catalyst for the preparation of quinolines from condensation of o-aminiarylketones and different ketones under solvent free conditions in high yield at 110 0C.
