Hypoxia Activated Prodrugs of a 9-Aza-anthrapyrazole Derivative That Has Promising Anticancer Activity

Mono- and his-N-oxides of a 9-aza-anthrapyrazole derivative having two 2-(dimethylamino)ethyl appendages were prepared by using a mild oxaziridine reagent. Biochemical and cell culture assays indicate that the bis-oxide is an inactive prodrug that readily converts to the active parent molecule under hypoxic conditions that are analogous to those present within certain tumors.