Chemistry:Fischer–Hepp rearrangement

Short description: Organic reaction applied to aromatic nitroso and nitrosamine compounds

Fischer-Hepp rearrangement
Named after	Otto Fischer Eduard Hepp
Reaction type	Rearrangement reaction
Identifiers
RSC ontology ID	RXNO:0000095

In organic chemistry, the Fischer–Hepp rearrangement is a rearrangement reaction in which an aromatic N-nitroso (–N=O) or nitrosamine (>N–N=O) converts to a carbon nitroso compound:

This organic reaction was first described by the German chemist Otto Philipp Fischer (1852–1932) and Eduard Hepp (June 11, 1851 – June 18, 1917) in 1886, and is of importance because para-NO secondary anilines cannot be prepared in a direct reaction.

The rearrangement reaction takes place by reacting the nitrosamine precursor with hydrochloric acid. The chemical yield is generally good under these conditions, but often much poorer if a different acid is used. The exact reaction mechanism is unknown but there is evidence suggesting an intramolecular reaction.

Sources

• Named Things in Chemical Industry

See also

• Friedel–Crafts alkylation-like reactions:
  • Hofmann-Martius rearrangement
  • Fries rearrangement