Synthesis of fused heterocycles: 1,2,3,4-tetrahydroisoquinolines and ring homologues via sulphonamidomethylation

The title heterocycles (3) have been obtained by a two-step synthesis; namely an initial intramolecular sulphonamidomethylation of N-aralkylsulphonamides (1) in acid media followed by desulphonylation of compounds (2) under moderate conditions, either by reduction or acid hydrolysis. Generally both steps gave good or high yields of compounds (3) variously substituted in the aromatic ring and with a six-, seven-, or eight-membered heterocyclic ring.