Abstract An extension of the Pomeranz-Fritsch procedure has been evaluated as a route to some polycyclic azaarenes. Aromatic aldehydes were treated with the dimethyl and diethyl acetals of 2-aminoethanal, the resulting imines reduced to amines which were tosylated and the resulting sulfonamides treated under a range of acidic conditions. The two naphthaldehydes led to benzo [f] isoquinoline and benzo [h] isoquinoline in overall yields ...