Several novel fused heterocyclic systems which have rings containing N/O or N/S have been synthesized through a facile one-pot method by the treatment of substituted 2-(benzo[d]thiazol-2-yl)phenol and cyanogen bromide in THF and NEt3. This one-pot method contains tough ring-opening of thiazole, special intermolecular rearrangement and ring-closing reactions. The newly synthesized compounds were characterized