In recent years, 1,2,3-benzotriazinones have been recognized as an alternative nitrogen- containing framework in a series of annulations and cross-coupling reactions under transition metal catalysis, as well as metal-free systems. A wide array of N-heterocycles and ortho- functionalized benzamides could be constructed through transformations of 1,2,3- benzotriazinones by the extrusion of a benign N2 gas. This review highlights recent advancements on the synthetic methodologies and organic transformations of 1,2,3- benzotriazinones.