Sydnone

Quality 0.50 · 1 view · Updated 2 months ago

title: "Sydnone" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["oxadiazoles", "simple-aromatic-rings", "lactones"] topic_path: "general/oxadiazoles" source: "https://en.wikipedia.org/wiki/Sydnone" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

|ImageFile=Sydnone circle structure.png |ImageSize = 120px |IUPACName=2H-Oxadiazol-5-one |OtherNames=1,2,3-Oxadiazol-5(2H)-one |Section1={{Chembox Identifiers | CASNo = 534-24-7 | PubChem=12443168 | ChemSpiderID = 65792731 | StdInChI=1S/C2H2N2O2/c5-2-1-3-4-6-2/h1,4H | StdInChIKey = BIGWXAGEQONZGD-UHFFFAOYSA-N | SMILES = C1=NNOC1=O |Section2={{Chembox Properties |C=2|H=2|N=2|O=2

Sydnones are mesoionic heterocyclic chemical compounds possessing a C5-oxygenated 1,2,3-oxadiazole core, named after the city of Sydney, Australia. Like other mesoionic compounds they are dipolar, possessing both positive and negative charges which are delocalized across the ring.

Discovery

N-phenylsydnone was first prepared in 1935 by and by cyclodehydration of N-Nitroso-N-phenylglycine with acetic anhydride. Later work showed that this could be applied fairly generally to the nitrosamines of N-substituted amino acids.

The parent compound sydnone is not synthetically accessible and may not exist.

Chemical structure

Sydnones have the following resonance structures. The exocyclic oxygen atom (O6) has a significant negative charge. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/3/34/Sydnone_Resonance_Structures.svg"] ::

Recent computational studies have indicated that sydnones and other similar mesoionic compounds are nonaromatic, "though well-stabilized in two separate regions by electron and charge delocalization."

Examples

  • Cefanone (Cephanone)
  • Ipramidil
  • 3-Thiomorpholino-sydnonimine
  • The reaction between methyl 3-benzyl-sydnone-4-acetate and diphenylacetylene is described in Ex1 of gives an analog of Bufezolac.
  • Synthesis and Biological Evaluation of Coumarinyl Sydnone Derivatives.

Related compounds

A sydnone imine in which the keto group of sydnone (=O) has been replaced with an imino (=NH) group can be found as a substructure in the stimulant drugs feprosidnine and mesocarb.

References

  • {{cite journal | title = Sydnone anions and abnormal N-heterocyclic carbenes of O-ethylsydnones. Characterizations, calculations and catalyses. |author1=S. Wiechmann |author2=T. Freese |author3=M. H. H. Drafz |author4=E. G. Hübner |author5=J. C. Namyslo |author6=M. Nieger |author7=A. Schmidt | journal = Chem. Commun. | volume = 50 | pages = 11822–11824 | year = 2014 |issue=80 | doi = 10.1039/C4CC05461J |pmid=25156208 | doi-access =free}}
  • {{cite journal | title = Synthesis of Sydnones and Sydnone Imines |author1=Claude V. Greco |author2=Wayne H. Nyberg |author3=C. C. Cheng | journal = Journal of Medicinal Chemistry | volume = 5 | issue = 4 | pages = 861–865 | year = 1962 | doi = 10.1021/jm01239a022 |pmid=14056419 }}
  • {{cite journal | title = Meso-ionic compounds |author1=Wilson Baker |author2=W. D. Ollis | journal = Quarterly Reviews, Chemical Society | volume = 11 | pages = 15–30 | year = 1957 | doi = 10.1039/QR9571100015 |s2cid=96888271 }}
  • {{cite journal | title = The Preparation of Substituted Hydrazines. I. Alkylhydrazines via Alkylsydnones |author1=Joseph Fugger |author2=Jack M. Tien |author3=I. Moyer Hunsberger | journal = J. Am. Chem. Soc. | volume = 77 | issue = 7 | pages = 1843–1848 | year = 1955 | doi = 10.1021/ja01612a039 }}
  • {{cite journal | title = The Preparation of Substituted Hydrazines. II.1 3-Pyridylhydrazine via the Phototropic N-(3-Pyridyl)-sydnone |author1=Jack M. Tien |author2=I. Moyer Hunsberger | journal = J. Am. Chem. Soc. | volume = 77 | issue = 24 | pages = 6604–6607 | year = 1955 | doi = 10.1021/ja01629a052 }} 88, 178 (1961);
  • {{cite journal | title = Sydnones. III. Preparation and Interconversion of Mercurated Derivatives of N-(3-Pyridyl)-sydnone1-3a |author1=Jack M. Tien |author2=I. Moyer Hunsberger | journal = J. Am. Chem. Soc. | volume = 83 | issue = 1 | pages = 178–182 | year = 1961 | doi = 10.1021/ja01462a035 }}
  • {{cite journal | author = Alan R. Katritzky | journal = Chem. Ind. | pages = 521 | year = 1955
  • {{cite journal | title = Some new mesoionic compounds |author1=Alexander Lawson |author2=D. H. Miles | journal = J. Chem. Soc. | pages = 2865–2871 | year = 1959 | doi = 10.1039/JR9590002865 }}
  • {{cite journal | title = A Kinetic Study of the Reaction of a "Meso-ionic" Compound (Dehydrodithizone) with Haloacetates |author1=J. Ogilvie |author2=V. K. Miyamoto |author3=Thomas C. Bruice | journal = J. Am. Chem. Soc. | volume = 83 | issue = 11 | pages = 2493–2495 | year = 1961 | doi = 10.1021/ja01472a017 }}
  • {{cite journal | title = A New Class of Central Nervous System Stimulants | author = LEMONT B. KIER, LAURETTA E. FOX, D. DHAWAN & I. W. WATERS | journal = Nature | volume = 195 | issue = 4843 | pages = 817–818 | year = 1962 | doi = 10.1038/195817a0 | pmid = 14455827 |bibcode = 1962Natur.195..817K | s2cid = 1683698

References

  1. "sydnones".
  2. (1 April 1964). "The Chemistry of the Sydnones". Chemical Reviews.
  3. (January 2010). "Recent developments in the chemistry of sydnones". Tetrahedron.
  4. (1935). "204. The action of acetic anhydride on N-nitrosophenylglycine and some of its derivatives". Journal of the Chemical Society (Resumed).
  5. (1998). "Are mesoionic compounds aromatic?". Canadian Journal of Chemistry.
  6. (2011). "Synthesis and Biological Evaluation of Coumarinyl Sydnone Derivatives". e-Journal of Chemistry.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::

oxadiazolessimple-aromatic-ringslactones