A new synthetic approach for the synthesis of novel 5H-dibenz[b,f]azepine, 5H-dibenz[b,f]-
azocine, 11H-benzo[f]pyrido[2,3-b]azepine and 6H-benzo[g]pyrido[2,3-c]azocine derivatives is
reported. The key step of this methodology is based on Friedel-Crafts ring closure of nitrogen
containing carboxylic acids and alkanols in the presence of AlCl3, P2O5 or PPA catalysts in
overall high yields. The starting carboxylic acids were prepared via an unequivocal synthetic
pathway by the basic hydrolysis of trimethyloxindole followed by N-arylation reactions.