Regioselective C3 ‐Nitration of Pyrazolo[1,5‐ a ]Pyrimidines With Fe( NO 3 ) 3 / TFA as a Nitrating Agent

ABSTRACT Nitro‐functionalized pyrazolo[1,5‐ a ]pyrimidines are valuable in materials science and energetics, but traditional methods typically require a mixture of sulfuric and nitric acids. This work presents a mild, iron‐complex‐mediated strategy for efficient C3‐selective nitration of pyrazolo[1,5‐ a ]pyrimidin‐7‐amines, providing direct access to these important scaffolds. The utility of this versatile method is highlighted by its successful application in late‐stage modification, gram‐scale synthesis, and further product diversification.