A Convenient Synthesis of Novel 2,8-Disubstituted Pyrido[3,4-b]pyrazines Possessing Biological Activity.

A regioselective synthetic route to 2,8-disubstituted pyrido[3,4-b]pyrazines, by initial condensation reaction between suitable diaminopyridines and α-keto aldehydes equivalents, has been developed. Focusing on the functionalization on C-8, 2-aryl-8-bromo- and 8-amino-2-arylpyrido[3,4-b]pyrazines have been synthesized. Anilines, amides, and ureas have been introduced at the 8-position from key intermediates. 2,8-Disubstituted pyrido[3,4- b]pyrazines thus prepared were found to be of biological interest. [ABSTRACT FROM AUTHOR]