An efficient and green synthesis of 3,3 '-benzylidenebis (4-hydroxy-6-methylpyridin-2(1H)-one) derivatives through multicomponent reaction in ionic liquid

A series of new 3,3'-benzylidenebis(4-hydroxy-6-methylpyridin-2(1H-one) derivatives were synthesized via a three-component reaction of an aldehyde, an aniline or ammonium acetate and 6-methyl-4-hydroxypyran-2-one in ionic liquid. These heterocyclic compounds produced could be conveniently separated from the reaction mixture without any volatile organic solvents, and the ionic liquid could be readily reused without efficiency loss after simple treatment.