Synthesis of unsymmetrical and regio-defined 2,3,6-quinoxaline and 2,3,7-pyridopyrazine derivatives

Differential reactivity of the amine functionality in a number of common 1,2-diamine starting materials is exploited to undertake an expedient synthesis of unsymmetrical 2,3,6-trisubstituted quinoxaline and unsymmetrical 2,3,7-trisubstituted pyridopyrazine derivatives.

A set of unsymmetrical and regio-defined quinoxalines and pyridinopyrazines were prepared. Regioselectivity was established by the use of differential reactivity in an aromatic diamine precursor.