A general, efficient and green method for the synthesis of quinoline derivatives via the Friedländer heteroannulation reaction of 2-aminoaryl ketones and α-methylene ketones has been developed, employing low melting mixtures of L-(+)-tartaric acid and urea derivatives as an inexpensive, non-toxic, easily biodegradable reaction medium. The melt acts as both the reaction medium and catalyst, furnishing quinolines in high to excellent yields.