One‐Pot Three‐Component Synthesis of Hantzsch 1,4‐Dihydropyridines Promoted by Dimethyl Phosphate Ionic Liquids

A one‐pot three‐component reaction of ethyl acetoacetate, AcONH₄, and different aldehydes has been successfully performed in the presence of ionic liquids (ILs) possessing a (MeO)₂PO$\rm{{_{2}^{-}}}$ counterion. The impact of electronic and steric effects of the substituents of aromatic aldehydes, as well as the influence of different anions of ILs on the product yield, have been investigated. The application of dimethyl phosphate ILs in the synthesis of Hantzsch 1,4‐dihydropyridines presents a simple method for obtaining structurally diverse products in moderate to high yields without using any additional catalyst.