Bis[(L)prolinato-N,O]Zn–water: A green catalytic system for the synthesis of 3,4-dihydropyrimidin-2 (1H)-ones via the Biginelli reaction

A novel, greener approach was adopted for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives (4a–i) using bis[(L)prolinato-N,O]Zn as an inexpensive, efficient and mild Lewis acid catalyst in water. The methodology offers several advantages such as short reaction time, high yields, clean process, low loading of catalyst and simple operational procedure. The catalyst was active up to five cycles and was identified by SEM-EDX analysis.

Graphical abstractBis[(L)prolinato-N,O]Zn–water is found to be an efficient and recyclable catalyst in promoting one-pot, three-component reactions of aldehydes, active methylene compounds and urea to afford a series of 3,4-dihydropyrimidin-2(1H)-ones in high yields. The catalyst was active up to five cycles and was identified by SEM-EDX analysis.Figure optionsDownload full-size imageDownload as PowerPoint slide