Tandem C-N Bond Formation through Condensation and Metal-Free N-Arylation: Protocol for Synthesizing Diverse Functionalized Quinoxalines.

Diverse functionalized quinoxalines were synthesized in good yields from arylamines and readily available β-keto oximes through condensation and metal-free N-arylation. The reaction was compatible with various functional groups, such as halides, cyano, and esters. A mechanism was proposed based on the experimental results. These quinoxalines were easily obtained on a gram scale and converted to various useful scaffolds. Compound LASSBio-1022 was prepared in 83% yield in two steps.