Development of new fluorescent xanthines as kinase inhibitors.

An efficient and versatile synthetic approach for the preparation of highly substituted xanthine derivatives has been developed by a combination of direct N7- and C8-arylation. With this method, diverse xanthine analogues were prepared and potent kinase inhibitors could be identified. For example, compound 8a inhibits PI3Ks and proliferation in T47D tumor cells. In addition, these xanthine-based kinase inhibitors exhibited significant fluorescence emission in a concentration-dependent response.