Bronsted acidic ionic liquid [C3SO3HDoim]HSO4 catalyzed one-pot three-component Biginelli-type reaction: An efficient and solvent-free synthesis of pyrimidinone derivatives and its mechanistic study

A series of Bronsted acidic ionic liquids (ILs) were prepared and used for Biginelli-type condensation reaction among aromatic aldehydes, urea or thiourea and cyclopentanone. Through this reaction, the synthesis of various pyrimidinones could be achieved. Of interest, it was found that the reaction was efficiently catalyzed by a novel, eco-friendly functionalized IL [C3SO3HDoim]HSO4, which could be reused for at least 7 times without significantly loss of catalytic activity. The reaction proceeded efficiently at 80 °C to afford the desired products in good yield (up to 96%). In addition, a possible mechanism that accounted for the IL [C3SO3HDoim]HSO4-catalyzed reaction was proposed.

Graphical abstractA novel functionalized Bronsted acidic ionic liquid [C3SO3HDoim]HSO4 was synthesized and characterized by IR, 1H NMR, 13C NMR and LC/MS. In this ionic liquid, Biginelli-type condensation reaction of aromatic aldehydes, urea or thiourea and cyclopentanone was carried out and a mechanism of the reaction was also proposed.Figure optionsDownload full-size imageDownload as PowerPoint slide