Abstract N-Benzylcinnamanilides cyclise with triflic acid to form 1-benzyl-4-aryl-2, 4-dihydro- 1H-quinolin-2-ones and 2, 5-diaryl-benzazepin-3-ones. The product ratio is determined by the preferred orientation of the amide and by the electronics of the substituents. With ortho- substituted anilides, N-debenzylation also occurs to give 4-aryl-2, 4-dihydro-1H-quinoline-2- ones.