Application of Suzuki–Miyaura and Buchwald–Hartwig Cross-coupling Reactions to the Preparation of Substituted 1,2,4-Benzotriazine 1-Oxides Related to the Antitumor Agent Tirapazamine

Abstract

Many 1,2,4-benzotriazine 1,4-dioxides display the ability to selectively kill the oxygen-poor cells found in solid tumors. As a result, there is a desire for synthetic routes that afford access to substituted 1,2,4-benzotriazine 1-oxides that can be used as direct precursors in the synthesis of 1,2,4-benzotriazine 1,4-dioxides. Here we describe the use of Suzuki–Miyaura and Buchwald–Hartwig cross-coupling reactions for the construction of various 1,2,4-benzotriazine 1-oxide analogs bearing substituents at the 3-position, 6-position, and 7-position.