Bruylants reaction

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In organic chemistry, the Bruylants reaction (sometimes misspelled Bruylant) is a substitution reaction in which a Grignard reagent replaces a nitrile on a carbon that also has an amino group. It is useful for synthesizing phenylcyclidine and related dissociative anesthetics. [1]

Unlike a traditional Grignard reaction where the nucleophile attacks the nitrile carbon, here the nitrile itself is lost as a leaving group. The reaction is named for Pierre Bruylants (1855–1950), [2] who first reported it in 1924. [3]

The reaction mechanism appears to involve ejection of the nitrile to form an iminium that is then attacked by the Grignard rather than a direct displacement such as an SN2 reaction. This accounts for the importance of the alpha amino group and the absence of stereoselectivity on chiral reaction sites. [4]

Modifications

1,2,3-Triazole and related heterocycles have been used as safer alternatives to the nitrile, as they avoid the typical use of cyanide to form the nitrile. [5]

Organolithium reagents can be used instead of the magesium-halide Grignard reagents, though they are more prone than Grignards to attack the nitrile itself. [6]

Related Research Articles

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<span class="mw-page-title-main">Ethyl cyanoacetate</span> Chemical compound

Ethyl cyanoacetate is an organic compound that contains a carboxylate ester and a nitrile. It is a colourless liquid with a pleasant odor. This material is useful as a starting material for synthesis due to its variety of functional groups and chemical reactivity.

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References

  1. Morris, Hamilton; Wallach, Jason (2014). "From PCP to MXE: A comprehensive review of the non-medical use of dissociative drugs". Drug Testing and Analysis. 6 (7–8): 614–632. doi:10.1002/dta.1620. PMID   24678061.
  2. Brother of Albert Bruylants  [ fr ], who was also a chemist
  3. Bruylants, P. (1924). Bull. Soc. Chim. Belg. 33: 467–478.{{cite journal}}: Missing or empty |title= (help)
  4. Mattalia, Jean-Marc Robert (2021). "The Bruylants and related reactions". Arkivoc: 1–19. doi: 10.24820/ark.5550190.p011.349 .
  5. Prashad, Mahavir; Liu, Yugang; Har, Denis; Repič, Oljan; Blacklock, Thomas J. (2005). "1,2,3-Triazole as a safer and practical substitute for cyanide in the Bruylants reaction for the synthesis of tertiary amines containing tertiary alkyl or aryl groups". Tetrahedron Letters. 46 (33): 5455–5458. doi:10.1016/j.tetlet.2005.06.066.
  6. Kalir, Asher; Edery, Habib; Pelah, Zvi; Balderman, D.; Porath, Gila (1969). "1-Phenylcycloalkylamine derivatives. II. Synthesis and pharmacological activity". Journal of Medicinal Chemistry. 12 (3): 473–477. doi:10.1021/jm00303a030. PMID   4977945.