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2181-42-2 - Trimethylsulfonium iodide, 99% - A12639 - Alfa Aesar

A12639 Trimethylsulfonium iodide, 99%

CAS Number

Size Price ($) Quantity Availability
50g 46.14
250g 194.67
1000g 548.80
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Trimethylsulfonium iodide, 99%


Chemical Properties

Formula Weight
Melting point
ca 215° subl.
Light Sensitive

Literature References

The ylide, generated with strong base, is a powerful methylene transfer reagent, converting aldehydes and ketones to epoxides; reaction with ɑß-enones also gives epoxides (contrast Trimethyl­sulfoxonium iodide, A14589): J. Am. Chem. Soc., 87, 1353 (1965):


Other conditions for addition to aldehydes include: phase-transfer catalysis: Angew. Chem. Int. Ed., 12, 845 (1973), KOH in acetonitrile: Tetrahedron Lett., 23, 5283 (1982), or KF on alumina: Tetrahedron, 41, 1259 (1985). With aryl aldehydes, the use of KO-t-Bu gives improved results by suppressing the competing Cannizzaro reaction: Org. Prep. Proced. Int., 27, 219 (1995). A simplified, solvent-free method employing KO-t-Bu has been reported for ketones: Heterocycles, 46, 185 (1997). With excess of the sulfonium ylide, ketones or epoxides give good yields of allylic alcohols, whereas aldehydes give poor yields. Under similar conditions, the sulfoxonium ylide gives oxetanes: Tetrahedron Lett., 35, 2009, 5449 (1994).


Methylene transfer to imines and arylhydrazones gives aziridines and N-arylaminoaziridines respectively: Synthesis, 330 (1983).


Addition to vinyl sulfones gives cyclopropyl sulfones: J. Org. Chem., 29, 3277 (1964). Similarly, vinylsulfonates and sulfonamides give cyclopropanes in fair to good yields: J. Org. Chem., 33, 3849 (1968).


Methylene transfer to allylic, propargylic, benzylic and primary alkyl halides and sulfonates results in formation of terminal alkenes in generally good yields: Tetrahedron Lett., 35, 5453 (1994).


Reaction with Ag2O gives the corresponding hydroxide, which is a useful methylating agent for various functional groups, including carboxylic acids, phenols, thiols and N-heterocycles: J. Org. Chem., 44, 638 (1979). Both the iodide and the hydroxide have been used for the methylation of pyrimidine nucleosides; see, e.g.: J. Chem. Soc., Perkin 1, 13 (1989).


GHS Hazard and Precautionary Statements

Hazard Statements: H315-H319-H335

Causes skin irritation. Causes serious eye irritation. May cause respiratory irritation.

Precautionary Statements: P261-P280-P305+P351+P338-P304+P340-P362-P312-P321-P405-P403+P233-P501a

Avoid breathing dust/fume/gas/mist/vapours/spray. Wear protective gloves/protective clothing/eye protection/face protection. IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. IF INHALED: Remove to fresh air and keep at rest in a position comfortable for breathing. Take off contaminated clothing and wash before reuse. Call a POISON CENTER or doctor/physician if you feel unwell. Specific treatment (see label). Store locked up. Store in a well-ventilated place. Keep container tightly closed. Dispose of contents/container in accordance with local/regional/national/international regulations.

Other References

Harmonized Tariff Code


  • A10478

    2,6-Lutidine, 98+%
  • A12824

    2-Methyl-1,3-dioxolane, 98%
  • A13320

    3-Quinuclidinone hydrochloride, 98+%
  • A13947

    Potassium tert-butoxide, 97%
  • 42780

    Dimethyl sulfoxide, HPLC grade, 99.9+%, packaged under Argon in resealable ChemSeal™ bottles

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