Synthesis of 1‐(2‐Methyl‐1,2,3,4‐tetrahydroquinolin‐4‐yl)pyrrolidin‐2‐ones from Anilines and N‐Vinyl Pyrrolidin‐2‐one Through Imino Diels—Alder Reaction Using 4‐Nitro Phthalic Acid as Catalyst.

Aryl amines react smoothly and efficiently with N-vinyl pyrrolidin-2-one in the presence of 4-nitro phthalic acid in acetonitrile to afford the corresponding 1-(2-methyl-1,2,3,4-tetrahydroquinolin-4-yl)pyrrolidin-2-ones in good yields.