3-Formylquinolin-2(1H)-ones have been synthesized efficiently by dechlorination of 2-chloro-3-formylquinolines with acetic acid and sodium acetate in just 1.5 to 2.5 min. under microwave irradiation. Consequently, microwave irradiation significantly reduced reaction times compared to traditional heating methods. Particularly synthesis by solvent-free solid supported microwave irradiation was found more eco-friendly and had higher reaction efficiency. The purity of the synthesized compounds was confirmed by their C, H and N analysis and the structure was analyzed on the basics of Mass, FT-IR and 1H NMR.