Divergent synthesis of novel 9-deazaxanthine derivatives via late-stage cross-coupling reactions.

A small library of 8-substituted 9-deazaxanthines has been prepared by late-stage diversification of an 8-bromo-9-deazaxanthine. By utilizing palladium-catalyzed cross-coupling reactions a single key precursor can be transformed into a variety of 8-substituted-9-deazaxanthine compounds. Three key 8-bromo-9-deazaxanthine intermediates were efficiently prepared from commercially available 6-chlorouracil in six steps.