Carbene‐Catalyzed Aroylation of a 2‐Chloroquinoxaline N‐Oxide with Aromatic Aldehydes at Room Temperature

Starting from easily accessible 2-chloro-3-(cyclopentyloxy)-7-fluoroquinoxaline 1-oxide, 12 new biologically promising aroylquinoxaline N-oxides were synthesized through carbene-catalyzed aroylation of the chloro nitrone unit with different aromatic aldehydes in the presence of 1,3-dimethylimidazolium iodide as the carbene precursor. The optimized reaction conditions tolerated a broad bandwidth of aldehydes and allowed the synthesis of the corresponding ketones in yields up to 87 %. Studies of their biological activities resulted in interesting specific cytotoxic effects against tumor cell lines.