Methylsulfonylmethane

Methylsulfonylmethane

Names
IUPAC name dimethyl sulfone
Preferred IUPAC name methanesulfonylmethane
Other names methyl sulfone methylsulfonylmethane sulfonylbismethane DMSO2
Identifiers
CAS Number	67-71-0 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:9349 Y
ChEMBL	ChEMBL25028 Y
ChemSpider	5978 Y
ECHA InfoCard	100.000.605
KEGG	C11142 Y
PubChem	6213
RTECS number	PB2785000
UNII	9H4PO4Z4FT Y
InChI InChI=1S/C2H6O2S/c1-5(2,3)4/h1-2H3 Y Key: HHVIBTZHLRERCL-UHFFFAOYSA-N Y InChI=1/C2H6O2S/c1-5(2,3)4/h1-2H3 Key: HHVIBTZHLRERCL-UHFFFAOYAG
SMILES [O-][S++]([O-])(C)C
Properties
Chemical formula	C2H6O2S
Molar mass	94.13 g·mol−1
Appearance	White crystalline solid
Density	1.45 g/cm3
Melting point	109 °C (228 °F; 382 K)
Boiling point	248 °C (478 °F; 521 K)
Hazards
Safety data sheet	External MSDS
S-phrases	S22 S24/25
NFPA 704	1 1
Flash point	143 °C (289 °F; 416 K)
Related compounds
Related compounds	DMSO dimethyl sulfide dimethyl sulfate sulfolane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Methylsulfonylmethane (MSM) is an organosulfur compound with the formula (CH₃)₂SO₂. It is also known by several other names including DMSO₂, methyl sulfone, and dimethyl sulfone. This colorless solid features the sulfonyl functional group and is considered relatively inert chemically. It occurs naturally in some primitive plants, is present in small amounts in many foods and beverages, and is marketed as a dietary supplement. It is also commonly found in the atmosphere above marine areas, where it is used as a carbon source by the airborne bacteria Afipia, and is found distinctively in human melanoma cells.

MSM and the corresponding sulfoxide dimethyl sulfoxide ((CH₃)₂SO, DMSO) have different physical properties. MSM is a white crystalline solid at STP (m.p. = 109 °C) whereas DMSO is a liquid under standard conditions. The sulfoxide is a highly polar aprotic solvent and is miscible with water; it is also an excellent ligand. MSM is less reactive than DMSO because the S-atom of the sulfone is already in its highest oxidation state (VI). Indeed, oxidation of the sulfoxide produces the sulfone, both under laboratory conditions and metabolically.

Because of its polarity and thermal stability, MSM is used industrially as a high-temperature solvent for both inorganic and organic substances. It is used as a medium in organic synthesis. For example, displacement of aryl chlorides by potassium fluoride can be usefully conducted in molten MSM. With a pK_a of 31, it can be deprotonated with sodium amide, and the conjugate base is an effective nucleophile.

The LD₅₀ (dose at which 50% of test subjects are killed by the high dosage) of MSM is greater than 17.5 grams per kilogram of body weight. In rats, no adverse events were observed after daily doses of 2 g MSM per kg of body weight. In a 90-day follow-up study, rats received daily MSM doses of 1.5 g/kg, and no changes were observed in terms of symptoms, blood chemistry or gross pathology.