Facile synthesis of N‐(methyl and phenyl)‐Δ4‐isoxazolines via the reaction of (Z)‐N‐(methyl and phenyl)‐C‐arylnitrones with dimethyl acethylenedicarboxylate, DMAD, in ionicliquid is described. (Z)‐N‐methyl‐C‐arylnitrones afforded the high yield of N‐methyl‐Δ4‐isoxazolines 4a, 4b, 4c, 4d, 4e in ionicliquid, [bmim]BF4, at room temperature. However, the reaction of (Z)‐N‐phenyl‐C‐arylnitrones with DMAD