Chemistry:Acyl azide

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Short description: Carboxylic acid derivative
General chemical structure of an acyl azide

Acyl azides are carboxylic acid derivatives with the general formula RCON3. These compounds, which are a subclass of organic azides, are generally colorless.[1]

Preparation

Typically acyl azides are generated under conditions where they rearrange to the isocyanate.[1]

Alkyl or aryl acyl chlorides react with sodium azide to give acyl azides.[2][3]

Preparation of acyl azides from acyl chlorides.png

The second major route to azides is from the acyl hydrazides with nitrous acid.[1]

Acyl azides have also been synthesized from various carboxylic acids and sodium azide in presence of triphenylphosphine and trichloroacetonitrile catalysts in excellent yields at mild conditions.[4] Another route starts with aliphatic and aromatic aldehydes reacting with iodine azide which is formed from sodium azide and iodine monochloride in acetonitrile.[5]

Uses

On Curtius rearrangement, acyl azides yield isocyanates.[6][7]

Curtius Rearrangement Scheme.png

Acyl azides are also formed in Darapsky degradation,[8][9][10]

Darapsky degradation

Historical references

References

  1. 1.0 1.1 1.2 Lwowski, Walter (1971). "Acyl azides". in Saul Patai. The Azido Group. PATAI'S Chemistry of Functional Groups. pp. 849–907. doi:10.1002/9780470771266.ch9. ISBN 9780470771679. 
  2. Allen, C. F. H.; Bell, Alan (1944). "Undecyl isocyanate". Organic Syntheses 24: 94. doi:10.15227/orgsyn.024.0094. http://www.orgsyn.org/demo.aspx?prep=cv3p0846. 
  3. Munch-Petersen, Jon (1953). "m-Nitrobenzazide (Benzoyl azide, m-nitro-)". Organic Syntheses 33: 53. doi:10.15227/orgsyn.033.0053. http://www.orgsyn.org/demo.aspx?prep=cv4p0715. 
  4. Jang, Doo; Kim, Joong-Gon (2008). "Direct Synthesis of Acyl Azides from Carboxylic Acids by the Combination of Trichloroacetonitrile, Triphenylphosphine and Sodium Azide". Synlett 2008 (13): 2072–2074. doi:10.1055/s-2008-1077979. 
  5. Marinescu, Lavinia; Thinggaard, Jacob; Thomsen, Ib B.; Bols, Mikael (2003). "Radical Azidonation of Aldehydes". J. Org. Chem. 68 (24): 9453–9455. doi:10.1021/jo035163v. PMID 14629171. 
  6. Smith, Peter A. S. (1946). "The Curtius reaction". Org. React. 3: 337–449. doi:10.1002/0471264180.or003.09. ISBN 0471264180. 
  7. Scriven, Eric F. V.; Turnbull, Kenneth (1988). "Azides: Their preparation and synthetic uses". Chem. Rev. 88 (2): 297–368. doi:10.1021/cr00084a001. 
  8. Gagnon, Paul E.; Boivin, Paul A.; Craig, Hugh M. (1951). "Synthesis of Amino Acids from Substituted Cyanoacetic Esters". Can. J. Chem. 29 (1): 70–75. doi:10.1139/v51-009. 
  9. E. H. Rodd (1965). Chemistry of Carbon Compounds (2nd ed.). New York. pp. 1157. 
  10. Gagnon, Paul E.; Nadeau, Guy; Côté, Raymond (1952). "Synthesis of α-Amino Acids from Ethyl Cyanoacetate". Can. J. Chem. 30 (8): 592–597. doi:10.1139/v52-071.