Synthesis of 5H-1,2,3-triazolo[4,3-a][2]benzazepines from the baylis-hillman adducts of 2-alkynylbenzaldehydes

The facile synthesis of 5H-1,2,3-triazolo[4,3-a][2]benzazepines 5a-d by the intramolecular 1,3-dipolar cycloaddition reaction of 2-alkynylphenylallyl azides 4a-d is described. The latter were readily obtained from 2-alkynylbenzaldehydes 1a-d through the Baylis-Hillman adducts 2a-d followed by acetylation to compounds 3a-d and nucleophilic substitution by azide to compounds 4a-d.