Oxazines

From Wikipedia, the free encyclopedia
The 8 existing isomers of oxazine[1]

Oxazines are heterocyclic compounds containing one oxygen and one nitrogen atom in a doubly unsaturated six-membered ring. Isomers exist depending on the relative position of the heteroatoms and relative position of the double bonds.

By extension, the derivatives are also referred to as oxazines; examples include ifosfamide and morpholine (tetrahydro-1,4-oxazine). A commercially available dihydro-1,3-oxazine is a reagent in the Meyers synthesis of aldehydes. Fluorescent dyes such as Nile red and Nile blue are based on the aromatic . Cinnabarine and cinnabaric acid are two naturally occurring dioxazines, being derived from biodegradation of tryptophan.[2]

Dioxazines[]

Dioxazines are pentacyclic compounds consisting of two oxazine subunits. A commercially important example is the pigment pigment violet 23.[3]

Synthetic route to dioxazine dyes.[4]

Benzoxazines[]

Benzoxazines are bicylic compounds formed by the ring fusion of a benzene ring with an oxazine. Polybenzoxazines are a class of polymers formed by the reaction of phenols, formaldehyde, and primary amines which on heating to ~200 °C (~400 °F) polymerise to produce polybenzoxazine networks.[5] The resulting high molecular weight thermoset polymer matrix composites are used where enhanced mechanical performance, flame and fire resistance compared to epoxy and phenolic resins is required.[6]

Benzoxazine resin synthetic pathway, structure and cure mechanism

Images[]

References[]

  1. ^ Theophil Eicher, Siegfried Hauptmann, Andreas Speicher: The Chemistry of Heterocycles: Structures, Reactions, Synthesis, and Applications, 3rd, Completely Revised and Enlarged Edition, John Wiley & Sons, p. 442 (Oxazines, p. 442, at Google Books).
  2. ^ Stone, Trevor W.; Stoy, Nicholas; Darlington, L. Gail "An expanding range of targets for kynurenine metabolites of tryptophan" Trends in Pharmacological Sciences 2013, volume 34, pp. 136-143.
  3. ^ Chamberlain, Terence "Dioxazine violet pigments" from High Performance Pigments Edited by Smith, Hugh M. 2002,185-194. doi:10.1002/3527600493.ch12
  4. ^ Horst Tappe, Walter Helmling, Peter Mischke, Karl Rebsamen, Uwe Reiher, Werner Russ, Ludwig Schläfer and Petra Vermehren "Reactive Dyes"in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH, Weinheim. doi:10.1002/14356007.a22_651
  5. ^ "BENZOXAZINE CHEMISTRY: A NEW MATERIAL TO MEET FIRE RETARDANT CHALLENGES OFAEROSPACE INTERIORS APPLICATIONS" (PDF).
  6. ^ Handbook of Benzoxazine Resins, ed. Hatsuo Ishida And Tarek Agag, Elsevier B.V., 2011, ISBN 978-0-444-53790-4

External links[]

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