New heteroarene-fused anthraquinones: Synthesis and PyBOP-mediated amination

In this study three independent synthetic approaches for fusing of oxo-bearing aza-heterocycles to the anthraquinone core were developed. In particular, quinoline-2-one, pyrimidine-4-one, pyrimidine-2,4-dione,[1,2,3]triazine-4-one, quinoxaline-2-one, quinoxaline-2,3-dione, and imidazole-2-one were successfully annelated expanding the scope of heteroarene-fused anthraquinone derivatives. Cyclic amines were introduced as potential pharmacophore fragments by the PyBOP-mediated substitution of the oxo group. The amination requires relatively mild conditions yielding the products with reasonable-to-good effectiveness, however some limitations were found. This work contributes to the synthesis and chemical modification of heteroarene-fused anthraquinone derivatives for application in anticancer research as potential protein-kinase inhibitors.