Nierenstein reaction
{{Short description|Chemical reaction}}
{{Reactionbox
| Name = Nierenstein reaction
| Type = Carbon-carbon bond forming reaction
| NamedAfter = Maximilian Nierenstein
}}
The Nierenstein reaction is an organic reaction describing the conversion of an acid chloride into a haloketone with diazomethane.{{cite journal
|author1=Clibbens, D. |author2=Nierenstein, M. | title = The action of diazomethane on some aromatic acyl chlorides
| journal = J. Chem. Soc.
| year = 1915
| volume = 107
| pages = 1491
| doi = 10.1039/CT9150701491| url = https://zenodo.org/record/1429737}}{{cite journal
|author1=Bachman, W. E. |author2=Struve, W. S.
| title = The Arndt-Eistert Reaction
| journal = Org. React.
| year = 1942
| volume = 1
| pages = 38 |author1-link=Werner Emmanuel Bachmann
}} (Review) It is an insertion reaction in that the methylene group from the diazomethane is inserted into the carbon-chlorine bond of the acid chloride.
Reaction mechanism
The reaction proceeds through a diazonium salt intermediate formed by displacement of the chloride with diazomethyl anion.
File:Nierenstein Reaktionsmechanismus-1.svg
If excess diazomethane is present during the reaction, it can act as a base, abstracting a hydrogen from the diazonium-salt intermediate. The result is a neutral diazoketone, which does not react with the chloride. Instead, the byproduct, diazonium-methyl from the other diazomethane molecule, can be attacked by the chloride to produce chloromethane. The unreactive diazoketone can be re-activated and reacted by treatment with hydrogen chloride to give the normal Nierenstein product.
File:Nierenstein reaction mechanism2.tif
In some cases, even limiting the amount of diazomethane gives a reaction process that stalls via the neutral diazoketone pathway, requiring the addition of HCl gas to rescue it.McPhee, W. D; Klingsberg, E. Organic Syntheses, Coll. Vol. 3, p.119 (1955); Vol. 26, p.13 (1946). ([http://www.orgsynth.org/orgsyn/pdfs/CV3P0119.pdf Article])
Scope
One original 1924 Nierenstein reaction:{{cite journal
| title = The Action of Diazomethane on some Aromatic Acyl Chlorides II. Synthesis of Fisetol
|author1=M. Nierenstein |author2=D. G. Wang |author3=J. C. Warr |name-list-style=amp | journal = J. Am. Chem. Soc.
| volume = 46
| issue = 11
| pages = 2551–2555
| year = 1924
| doi = 10.1021/ja01676a028 }}
and a reaction starting from benzoyl bromide going haywire with formation of the dioxane dimer:{{cite journal
| title = The Action of Diazomethane on some Aromatic Acyl Chlorides III. The Mechanism of the Reaction
|author1=H. H. Lewis |author2=M. Nierenstein |author3=Enid M. Rich |name-list-style=amp | journal = J. Am. Chem. Soc.
| volume = 47
| issue = 6
| pages = 1728–1732
| year = 1925
| doi = 10.1021/ja01683a036}}
See also
- Maximilian Nierenstein
- Curtius rearrangement
- Wolff rearrangement
- Arndt–Eistert reaction: where acid chlorides react with diazomethane to give chain extended carboxylic acids via a rearrangement