Fischer–Hepp rearrangement explained

In organic chemistry, the Fischer–Hepp rearrangement is a rearrangement reaction in which an aromatic N-nitroso or secondary nitrosamine converts to a carbon nitroso compound:^{[1] [2]}

This organic reaction was first described by the German chemist Otto Philipp Fischer (1852–1932) and Eduard Hepp (June 11, 1851 – June 18, 1917) ^[3] 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, similar to that seen in the Bamberger rearrangement.

Sources

• Web site: Andraos . John . 2000–2012 . Named Things in Chemical Industry . live . https://web.archive.org/web/20230407175424/http://careerchem.com/NAMED/Industry.pdf . 2023-04-07 . 2024-05-01 . Named Things in Chemistry & Physics.

See also

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

References

1. Fischer . Otto . Hepp . Eduard . July–December 1886 . Zur Kenntniss der Nitrosamine . Berichte der Deutschen Chemischen Gesellschaft zu Berlin . en . 19 . 2 . 2991–2995 . 10.1002/cber.188601902297 . 0365-9496 . 1099-0682 . 95280925 . Zenodo 1425449. Gallica ark:/12148/bpt6k907075/f473.item . free . 2027/njp.32101044028619?urlappend=%3Bseq=1121.
2. M B Smith, J March. March's Advanced Organic Chemistry (Wiley, 2001) / Book: Michael B., Smith . March's Advanced Organic Chemistry - Reactions, Mechanisms, and Structure . 2013 . John Wiley & Sons, Inc. . 978-0-470-46259-1 . 7th . Hoboken, New Jersey . 639 . 11.6.2.2 Groups Cleaving from Nitrogen; Reaction 11-29: Migration of the Nitroso Group: The Fischer–Hepp Rearrangement . 2012027160.
3. Book: Pötsch . Winfried R. . Lexikon bedeutender Chemiker . Fischer . Annelore . Müller . Wolfgang . 1988–1989 . Verlag Harri Deutsch / VEB Bibliographisches Institut Leipzig . With the collaboration of Heinz Cassebaum . 3-8171-1055-3 . Thun & Frankfurt . 148, 197.