Ionic liquid phase organic synthesis (IoLiPOS) methodology applied to the three component preparation of 2-thioxo tetrahydropyrimidin-4-(1H)-ones under microwave dielectric heating

An ionic liquid phase organic synthesis (IoLiPOS) has been developed for the preparation of 2-thioxo tetrahydropyrimidin-4(1H)-ones. Treatment of the starting poly(ethyleneglycol)ionic liquid phases (PEGn-ILPs) with acryloyl chloride afforded a serie of (PEGn)-ILPs bound acrylate in quantitative yields. Michael addition of aliphatic primary amines to the PEG1-ILPs () allowed the preparation of β-aminoesters in high yields. Addition of alkyl isothiocyanates to gave the corresponding thioureido esters in the third step. The final cyclization-cleavage under microwave/solventless strategy provides, under basic conditions, the expected 2-thioxo tetrahydropyrimidin-4(1H)-ones in high purity after flash chromatography. According to the IoLiPOS methodology, the NMR method was used to establish loading of all the PEG-ionic liquid phases intermediates.