Sequential Synthesis, Olfactory Properties, and Biological Activity of Quinoxaline Derivatives.

A simple, practical, and rapid access to quinoxalin-2-ones 1, 1,2,3,4-tetrahydroquinoxalines 2, quinoxalines 3, and quinoxalin-2(1H)-ones 4 has been achieved, based on the copper-catalyzed quinoxalinone formation of 2-haloanilines and amino acids followed by their reduction and oxidation. The olfactory properties and lipid accumulation inhibitory activity in cultured hepatocytes of the quinoxaline derivatives were also evaluated.