Oxidant‐Mediated Nitrogenation and Recyclization of Imidazo[1,2‐a]pyridines with Sodium Azide: Synthesis of 4H‐Pyrido[1,2‐a][1,3,5]triazin‐4‐ones

Abstract

AbstractAn expeditious and straightforward approach for the synthesis of 4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐ones starting from readily available imidazo[1,2‐a]pyridines and sodium azide has been presented under aerobic oxidative conditions. The reaction proceeded well with the promotion of potassium persulfate/potassium permanganate with good functional group tolerance. A wide range of biologically valuable 4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐one scaffolds were assembled by this methodology. The gram‐scale reaction was also achieved. A cascade nitrogenation and oxidative recyclization sequence could be involved in the reaction.magnified image