New methodology for the synthesis of 2-pyridones using basic Al2O3 as catalyst

A novel series of 2-pyridones derivatives have prepared by new multi-component reaction (MCR) in excellent yields. The first step of this methodology is the reaction of methylcetones 1a-c with N, N-dimethylformamide dimethyl acetal under microwave irradiation affords the corresponding enaminone 2a-c which is the key intermediary of our synthetic method. The second step is one pot reaction of enaminones with ethyl 2-cyanoacetate in the presence of basic Al2O3 as catalyst without solvent. Structural assignments are based on spectroscopic data (IR, 1H NMR, 13C NMR, mass spectra). This method has the advantage of short time, high yields and being environmentally-friendly.