One application is in the synthesis of fenhexamid [fr].
Reaction mechanism
The mechanism of the Bamberger rearrangement proceeds from the monoprotonation of N-phenylhydroxylamine 1. N-protonation 2 is favored, but unproductive. O-protonation 3 can form the nitrenium ion4, which can react with nucleophiles (H2O) to form the desired 4-aminophenol 5.[6][7]
^Oxley, P. W.; Adger, B. M.; Sasse, M. J.; Forth1, M. A. (1989). "N-Acetyl-N-Phenylhydroxylamine Via Catalytic Transfer Hydrogenation of Nitrobenzene Using Hydrazine and Rhodium on Carbon". Organic Syntheses. 67: 187. doi:10.15227/orgsyn.067.0187.{{cite journal}}: CS1 maint: numeric names: authors list (link)
^Sone, T.; Hamamoto, K.; Seiji, Y.; Shinkai, S.; Manabe, O. (1981). "Kinetics and Mechanisms of the Bamberger Rearrangement. Part 4. Rearrangement of Sterically Hindered Phenylhydroxylamines to 4-Aminophenols in Aqueous Sulphuric Acid Solution". Journal of the Chemical Society, Perkin Transactions 2. 1981 (2): 1596–1598. doi:10.1039/P29810000298.
^Kohnstam, G.; Petch, W. A.; Williams, D. L. H. (1984). "Kinetic Substituent and Isotope Effects in the Acid-Catalysed Rearrangement of N-Phenylhydroxylamines. Are Nitrenium Ions Involved?". Journal of the Chemical Society, Perkin Transactions 2. 1984 (3): 423–427. doi:10.1039/P29840000423.