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Oxazole



Oxazole

Systematic (IUPAC) name
1,3-oxazole
Identifiers
PubChem          ?
Chemical data
Formula C3H3NO 
Molar mass 69.06
Complete data

Oxazole is the parent compound for vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitrogen separated by one carbon [1].

Additional recommended knowledge

Contents

Biochemistry

In biomolecules, oxazoles result from the cyclization and oxidation of serine or threonine nonribosomal peptides:

Oxazoles are not as abundant in biomolecules as the related thiazoles with oxygen replaced by a sulfur atom.

Properties

Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak base with pKa of conjugate acid of 0.8 compared to 7 for imidazole.

Organic synthesis

Classical oxazole synthetic methods in organic chemistry are

  • the Robinson-Gabriel synthesis by dehydration of 2-acylaminoketones
  • the Fischer oxazole synthesis from cyanohydrins and aldehydes
  • the Bredereck reaction with α-haloketones and formamide

Other methods are reported in the literature.

Organic reactions

in the balanced half-reaction three equivalents of water are consumed for each equivalent of oxazoline generating 4 protons and 4 electrons the latter derived from CeIV.

See also

References

  1. ^ Heterocyclic Chemistry TL Gilchrist, The Bath press 1985 ISBN 0-582-01421-2
  2. ^ A new consecutive three-component oxazole synthesis by an amidation–coupling–cycloisomerization (ACCI) sequence Eugen Merkul and Thomas J. J. Müller Chem. Commun., 2006, 4817 - 4819, doi:10.1039/b610839c
  3. ^ Fully Automated Continuous Flow Synthesis of 4,5-Disubstituted Oxazoles Marcus Baumann, Ian R. Baxendale, Steven V. Ley, Christoper D. Smith, and Geoffrey K. Tranmer Org. Lett.; 2006; 8(23) pp 5231 - 5234; (Letter) doi:10.1021/ol061975c
  4. ^ They react together in the first phase in a continuous flow reactor to the intermediate enol and then in the second phase in a phosphazene base (PS-BEMP) induced cyclization by solid-phase synthesis.
  5. ^ Ceric Ammonium Nitrate Promoted Oxidation of Oxazoles David A. Evans, Pavel Nagorny, and Risheng Xu Org. Lett.; 2006; 8(24) pp 5669 - 5671; (Letter) doi:10.1021/ol0624530
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Oxazole". A list of authors is available in Wikipedia.
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