An efficient and solvent-free one-pot synthesis of 1,4-dihydropyridines under microwave irradiation

An efficient synthesis of 1,4-dihydropyridines using lanthanum oxide as a catalyst from aldehydes, β-ketoester and ammonium acetate without solvent under the irradiation of microwave is described. Compared with the classical Hantzsch reaction, this new method has the advantage of good yield (90–98%) and short reaction time (40–80 s).