Hösch reaction

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The Hösch reaction (also known as the Hoesch reaction or Houben-Hoesch reaction) is an organic reaction in which a nitrile reacts with an arene compound to form a aryl ketone. the reaction is a type of Friedel-Crafts acylation with hydrochloric acid and a Lewis acid catalyst.

An example is the synthesis of 1-(2,4, 6-Trihydroxyphenyl)ethanone from phloroglucinol [1]:

Houben-Hoesch reaction

A ketimine is isolated as an intermediate reaction product. The attacking electrophile is possibly [2] a species of the type R-C+=NHCl-. The arene must be electron-rich i.e. phenol or aniline type. A related reaction is the Gattermann reaction in which hydrocyanic acid not a nitrile is used.

The reaction is named after Kurt Hoesch [3] and J. Houben [4] who reported about this new reaction type in respectively 1915 and 1926.


[edit] References

  1. ^ Organic Syntheses, Coll. Vol. 2, p.522 (1943); Vol. 15, p.70 (1935). http://www.orgsynth.org/orgsyn/pdfs/CV2P0522.pdf
  2. ^ March, Jerry (1985). Advanced Organic Chemistry, Reactions, Mechanisms and Structure, third Edition, John Wiley & Sons. ISBN 0-471-85472-7. 
  3. ^ Eine neue Synthese aromatischer Ketone. I. Darstellung einiger Phenol-ketone Berichte der deutschen chemischen Gesellschaft Volume 48, Issue 1, Date: Januar-Juni 1915, Pages: 1122-1133 Kurt Hoesch doi:10.1002/cber.191504801156
  4. ^ Über die Kern-Kondensation von Phenolen und Phenol-äthern mit Nitrilen zu Phenol- und Phenol-äther-Ketimiden und -Ketonen (I.) Berichte der deutschen chemischen Gesellschaft (A and B Series) Volume 59, Issue 11, Date: 8. Dezember 1926, Pages: 2878-2891 J. Houben doi:10.1002/cber.19260591135