Gattermann reaction

For the conversion of benzenediazonium chloride to a haloarene (also referred to as the 'Gattermann reaction'), see Diazonium compound § Gattermann reaction.
Gattermann formylation
Named after Ludwig Gattermann
Reaction type Substitution reaction
Identifiers
RSC ontology ID RXNO:0000139

The Gattermann reaction (also known as the Gattermann formylation and the Gattermann salicylaldehyde synthesis) is a chemical reaction in which aromatic compounds are formylated by a mixture of hydrogen cyanide (HCN) and hydrogen chloride (HCl) in the presence of a Lewis acid catalyst such as aluminium chloride (AlCl3).[1] It is named for the German chemist Ludwig Gattermann[2] and is similar to the Friedel–Crafts reaction.

Modifications have shown that it is possible to use sodium cyanide or cyanogen bromide in place of hydrogen cyanide.[3]

The reaction can be simplified by replacing the HCN/AlCl3 combination with zinc cyanide.[4] Although it is also highly toxic, Zn(CN)2 is a solid, making it safer to work with than gaseous HCN.[5] The Zn(CN)2 reacts with the HCl to form the key HCN reactant and Zn(Cl)2 that serves as the Lewis-acid catalyst in-situ. An example of the Zn(CN)2 method is the synthesis of mesitaldehyde from mesitylene.[6]

  1. ^ Smith, Michael B.; March, Jerry (2007), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, p. 725, ISBN 978-0-471-72091-1
  2. ^ Gattermann, L.; Berchelmann, W. (1898). "Synthese aromatischer Oxyaldehyde". Berichte der deutschen chemischen Gesellschaft. 31 (2): 1765–1769. doi:10.1002/cber.18980310281.
  3. ^ Karrer, P. (1919). "Über Oxycarbonylverbindungen I. Eine neue Synthese von" [Hydroxycarbonyl compounds. I. A new synthesis of hydroxyaldehydes]. Helvetica Chimica Acta (in German). 2 (1): 89–94. doi:10.1002/hlca.19190020109.
  4. ^ Adams R.; Levine, I. (1923). "Simplification of the Gattermann Synthesis of Hydroxy Aldehydes". J. Am. Chem. Soc. 45 (10): 2373–77. doi:10.1021/ja01663a020.
  5. ^ Adams, Roger (1957). Organic Reactions, Volume 9. New York: John Wiley & Sons, Inc. pp. 38 & 53–54. doi:10.1002/0471264180.or009.02. ISBN 9780471007265.
  6. ^ Fuson, R. C.; Horning, E. C.; Rowland, S. P.; Ward, M. L. (1955). "Mesitaldehyde". Organic Syntheses. doi:10.15227/orgsyn.023.0057; Collected Volumes, vol. 3, p. 549.