Formation of Quinoxaline Monoxides from Reaction of Benzofurazan Oxide with Enones and 13C NMR Correlations of Quinoxaline N-Oxides

Article abstract of DOI:10.1021/jo01298a030

Benzofuran oxide (1) reacts with a variety of enones and amines to give quinoxaline monoxides.The nature of the amine determines the regiochemistry of the product: secondary amines give a type 4 product and primary amines give a type 5 product.Reaction of 1, cinnamaldehyde, and morpholine gave both 4a and 8a.The regiochemistry of these N-oxide products is discussed in terms of intermediate 11.Principal limitations of these reactions for synthesis are the low yields and the lack of universality for enones as substrates. 13C NMR correlations for quinoxaline monoxides and dioxides are presented.