TiCl4‐Mediated Dealkylative Cyclization of Arylidene‐azol‐ones.

A new general approach for the synthesis of azolo[4,5‐b]quinolines via dealkylative TiCl4‐mediated cyclization of 2‐dialkylamino‐arylidene‐azol‐ones upon heating in dichloroethane is found. The reaction scope and limitations are established, showing that at least two different heterocyclic cores could be obtained. Dozen products were obtained in moderate to good yields (22–64 %). [ABSTRACT FROM AUTHOR]