TiCl₄‐Mediated Dealkylative Cyclization of Arylidene‐azol‐ones

Abstract

A new general approach for the synthesis of azolo [4,5b]quinolines via dealkylative TiCl 4 -mediated cyclization of 2dialkylamino-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 %).

Facile Condensation of 2‐Aminobenzaldehydes into Azolo[4,5‐b]Quinolones

“…Full experimental details, characterization data, and copies of 1 H and 13 C spectra for newly synthesized compounds.…”

“…Recently, we have discovered a reaction 2‐amino‐arylidene‐thiazolidin‐2,4‐diones with titanium tetrachloride, which leads to the formation of thiazolo[4,5‐b]quinolin‐2(4 H )‐ones through desalkylation on nitrogen atom followed by condensation (Scheme 2). [13] Although this method provided direct access to the desired compounds, it was limited to this specific class of azolones and also did not allow variation of the substituents at the nitrogen atom. The present work advances and logically continues the previous work by using of monoalkylanilines without the need for desalkylation.…”

Synthesis of Indole‐2‐carboxylates via Condensation of Nitroacetic Esters and 2‐Dimethylbenzaldehydes

“…The authors have cited additional references within the Supporting Information. [31][32][33][34][35][36][37][38][39] The Supporting Information includes compounds characterization data and NMR spectra ( 1 H and 13 C).…”