Metal-free, late-stage nitration strategy to construct 6-(ortho-nitroaryl)amino purine derivatives enabled by t-BuONO

A late-stage, green and practical preparation of 6-(ortho-nitroaryl) amino purine derivatives was reported by using t-BuONO as the nitrating agent without transition-metal catalysts under air conditions. This method tolerates a wide variety of functional groups and is applicable for the gram scale synthesis, which may prove instrumental for further application in biochemistry. Preliminary mechanism was proposed through a series of experiments.