What is Fischer-Hepp rearrangement?
The Fischer-Hepp rearrangement, which is also known as the nitrosamine rearrangement, is a chemical reaction that results in the rearrangement of secondary aromatic nitrosamines to form p-nitrosoarylamines.

References
Fischer, O. and Hepp, E. (1886), Zur Kenntniss der Nitrosamine. [On the knowledge of nitrosamines.] Ber. Dtsch. Chem. Ges., 19: 2991-2995. https://doi.org/10.1002/cber.188601902297
Full Professor of Organic Chemistry at the University of Granada, with a long-standing research career in Computational Chemistry and molecular modeling and design.