Improved Protocol for Mononitration of Phenols with Bismuth(III) and Iron(III) Nitrates

A simple and efficient multigram procedure was developed for the selective mononitration of various activated phenols. The reaction proceeded smoothly with 0.5 equivalents of Bi(NO3)3 · 5H2O or Fe(NO3)3 · 9H2O in acetone at ambient temperature or at reflux. The desired products were isolated in 62–93% total yield and essentially no overnitrated compounds were detected.