[ EMIM ] AlCl 4 ‐ionic liquid catalyzed mechanochemically assisted synthesis of 3,4‐dihydropyrimidin‐2‐( 1H )‐one and thione derivatives

[EMIM]AlCl 4 (1‐ethyl‐3‐methylimidazolium tetrachloroaluminate) ionic liquid catalyzed mechanochemically assisted methodology for the Biginelli reaction has been developed successfully. One‐pot, multicomponent reaction between ethyl/methyl acetoacetate, urea/thiourea, and various aromatic/aliphatic and heterocyclic aldehydes in presence of catalytic amount of [EMIM]AlCl 4 under grinding conditions in ethanol affords 3,4‐dihydropyrimidin‐2‐(1H)‐one and its thione derivatives. Short reaction time, inclusion of eco‐friendly solvent, moderate to high yield of the product, and operational simplicity are some of the noteworthy features of this protocol. In consequence, the described procedure finds an alternative way to existing methods for the synthesis of the titled compounds.