Ketoanilides containing alkyl side chains were readily cyclized to 3-hydroxy-2-oxindoles or spirooxindoles by a single or double intramolecular Friedel–Crafts reaction in the presence of trifluoroacetic acid (TFA) at room temperature or at 45° C. α-Iminocarboxamides, generated in situ from ketoamides, cyclized similarly to 3-aminooxindoles under identical conditions.