Fischer-Hepp rearrangement
In chemistry , the Fischer-Hepp rearrangement is a rearrangement reaction that was named after its discoverers, the German chemists Otto Philipp Fischer (1852-1932) and Eduard Hepp (1851-1917).
Overview reaction
In the Fischer-Hepp rearrangement , an aromatic nitrosamine 1 is rearranged into an isomeric nitroso compound 2 . It enables the synthesis of N -monoalkylated aniline , which is substituted in the para position by a nitroso group :
The rearrangement takes place through the action of hydrochloric acid on nitrosamine 1 . The chemical yield of the reaction is generally good under these conditions, but is often reduced when a different acid is used.
mechanism
The exact mechanism of the reaction is unknown, but it appears to be an intramolecular reaction, as the rearrangement also occurs in the presence of urea , which would have trapped nitrous acid or nitrosyl chloride .
Individual evidence
- ^ Winfried R. Pötsch, Annelore Fischer and Wolfgang Müller with the collaboration of Heinz Cassebaum : Lexicon of important chemists . Bibliographisches Institut, Leipzig 1988, ISBN 3-323-00185-0 , p. 197.
- ↑ Otto Fischer, Eduard Hepp: On the knowledge of nitrosamines . In: Reports of the German Chemical Society . tape 19 , no. 2 , July 1886, p. 2991–2995 , doi : 10.1002 / cber.188601902297 .
- ↑ Michael B. Smith: March's advanced organic chemistry . 7th edition, John Wiley & Sons, 2013, ISBN 978-0-470-46259-1 , p. 639.
- ↑ Bradford P. Mundy, Michael G. Ellert, Frank G. Favaloro, Jr .: Name Reactions in Organic Synthesis . Wiley & Sons, 2nd edition, 2005, ISBN 0-471-22854-0 , p. 246.
- ↑ a b Ivan Ernest: Binding, structure and reaction mechanisms in organic chemistry . Springer, 1972, ISBN 3-211-81060-9 , pp. 272-273.