sulfone
{{Short description|1=Organosulfur compound of the form >S(=O)2}}
File:Dimethylsulfone-3D-vdW.png, an example of a sulfone]]
In organic chemistry, a sulfone is a organosulfur compound containing a sulfonyl ({{chem2|R\sS(\dO)2\sR’}}) functional group attached to two carbon atoms. The central hexavalent sulfur atom is double-bonded to each of two oxygen atoms and has a single bond to each of two carbon atoms, usually in two separate hydrocarbon substituents.{{cite book | last = Hornback | first = Joseph | title = Organic Chemistry | publisher = Thomson Brooks/Cole | location = Australia | year = 2006 | isbn = 978-0-534-38951-2}}
Synthesis and reactions
=By oxidation of thioethers and sulfoxides=
Sulfones are typically prepared by organic oxidation of thioethers, often referred to as sulfides. Sulfoxides are intermediates in this route.{{cite journal|title=Phenyl Vinyl Sulfone and Sulfoxide|author=Leo A. Paquette, Richard V. C. Carr|journal=Org. Synth.|year=1986|volume=64|page=157|doi=10.15227/orgsyn.064.0157}} For example, dimethyl sulfide oxidizes to dimethyl sulfoxide and then to dimethyl sulfone.
=From SO<sub>2</sub>=
:Image:Sulfolane synthesis.png of sulfolene.]]
Sulfur dioxide is a convenient and widely used source of the sulfonyl functional group. Specifically, Sulfur dioxide participates in cycloaddition reactions with dienes.{{cite journal|title=Isoprene Cyclic Sulfone|author=Robert L. Frank and Raymond P. Seven|journal=Org. Synth.|year=1949|volume=29|pages=59|doi=10.15227/orgsyn.029.0059}}
The industrially useful solvent sulfolane is prepared by addition of sulfur dioxide to buta-1,3-diene followed by hydrogenation of the resulting sulfolene.{{Ullmann | first = Hillis O. | last = Folkins | chapter = Benzene | date = 2005 | DOI = 10.1002/14356007.a03_475}}
=From sulfonyl and sulfuryl halides=
Sulfones are prepared under conditions used for Friedel–Crafts reactions using sources of {{chem|RSO|2|+}} derived from sulfonyl halides and sulfonic acid anhydrides. Lewis acid catalysts such as {{chem2|AlCl3}} and {{chem2|FeCl3}} are required.{{cite journal |author1=Truce, W. E. |author2=Vriesen |author3=C. W. | title = Friedel—Crafts Reactions of Methanesulfonyl Chloride with Benzene and Certain Substituted Benzenes| year = 1953 | journal = J. Am. Chem. Soc. | volume = 75 | pages = 5032–5036 | doi = 10.1021/ja01116a043 | issue = 20}}{{Cite journal | last1 = Répichet | first1 = S. | last2 = Le Roux | first2 = C. | last3 = Hernandez | first3 = P. | last4 = Dubac | first4 = J. | last5 = Desmurs | first5 = J. R. | title = Bismuth(III) Trifluoromethanesulfonate: An Efficient Catalyst for the Sulfonylation of Arenes | doi = 10.1021/jo9902603 | journal = The Journal of Organic Chemistry | volume = 64 | issue = 17 | pages = 6479–6482 | year = 1999 }}{{cite journal |author1=Truce, W. E. |author2=Milionis, J. P. | title = Friedel-Crafts Cyclization of ω-Phenylalkanesulfonyl Chlorides | year = 1952 | journal = J. Am. Chem. Soc. | volume = 74 | pages = 974–977 | doi = 10.1021/ja01124a031 | issue = 4}}
Sulfones have been prepared by nucleophilic displacement of halides by sulfinates:{{cite journal|title=4,4'-Diaminodiphenylsulfone|author=C. W. Ferry, J. S. Buck, R. Baltzly|journal=Org. Synth.|year=1942|volume=22|pages=31|doi=10.15227/orgsyn.022.0031}}
=Reactions=
Sulfone is a relatively inert functional group, typically less oxidizing and 4 bel more acidic than sulfoxides. In the Ramberg–Bäcklund reaction and the Julia olefination, sulfones are converted to alkenes by the elimination of sulfur dioxide.{{cite book | first1 = Francis A. | last1 = Carey | first2 = Richard J. | last2 = Sundberg | title = Advanced Organic Chemistry | publisher = Springer | location = Berlin | year = 2007 | isbn = 978-0-387-68354-6}} However, sulfones are unstable to bases, eliminating to give an alkene.Smith (2020), March's Organic Chemistry, rxn. 17-10.
Sulfones can also undergo desulfonylation.
Vinyl sulfones are electrophilic and behave as Michael acceptors.
Applications
Sulfolane is used to extract valuable aromatic compounds from petroleum.
=Polymers=
Some polymers containing sulfone groups are useful engineering plastics. They exhibit high strength and resistance to oxidation, corrosion, high temperatures, and creep under stress. For example, some are valuable as replacements for copper in domestic hot water plumbing.{{cite book | last = Fink | first = Johannes | title = High Performance Polymers | publisher = William Andrew | location = Norwich | year = 2008 | isbn = 978-0-8155-1580-7}} Precursors to such polymers are the sulfones bisphenol S and 4,4′-dichlorodiphenyl sulfone.
=Pharmacology=
file:Dapsone.svg, an antibiotic used for the treatment of leprosy.{{cite book |author1=Thomas L. Lemke |title=Foye's Principles of Medicinal Chemistry |date=2008 |publisher=Lippincott Williams & Wilkins |isbn=9780781768795 |page=1142 |url=https://books.google.com/books?id=R0W1ErpsQpkC&pg=PA1142 |url-status=live |archive-url=https://web.archive.org/web/20160304193954/https://books.google.ca/books?id=R0W1ErpsQpkC&pg=PA1142 |archive-date=2016-03-04}}]]
Examples of sulfones in pharmacology include dapsone, a drug formerly used as an antibiotic to treat leprosy, dermatitis herpetiformis, tuberculosis, or pneumocystis pneumonia (PCP). Several of its derivatives, such as promin, have similarly been studied or actually been applied in medicine, but in general sulfones are of far less prominence in pharmacology than for example the sulfonamides.{{cite book | first1 = Charles R. | last1 = Craig | first2 = Robert E. | last2 = Stitzel | title = Modern Pharmacology with Clinical Applications | publisher = Lippincott Williams & Wilkins | location = Hagerstwon | year = 2004 | isbn = 978-0-7817-3762-3}}{{cite book | first1 = Victor Alexander | last1 = Drill | first2 = Joseph R. | last2 = Di Palma | title = Drill's Pharmacology in Medicine | publisher = McGraw-Hill | location = New York | year = 1971 | isbn = 978-0-07-017006-3}}
See also
{{Commons category|Sulfones}}
- Organosulfur chemistry
- Sulfonanilide
- Sulfoxide
- Sulfonic acid (–OH substituent)