Sulfolane

Sulfolane

Names
IUPAC name Tetrahydrothiophene 1,1-dioxide
Other names sulfolane tetramethylene sulfone
Identifiers
CAS Number	126-33-0 N
3D model (Jmol)	Interactive image
ChEBI	CHEBI:74794 N
ChemSpider	29080 Y
ECHA InfoCard	100.004.349
PubChem	31347
UNII	Y5L06AH4G5 Y
InChI InChI=1S/C4H8O2S/c5-7(6)3-1-2-4-7/h1-4H2 Y Key: HXJUTPCZVOIRIF-UHFFFAOYSA-N Y InChI=1/C4H8O2S/c5-7(6)3-1-2-4-7/h1-4H2 Key: HXJUTPCZVOIRIF-UHFFFAOYAA
SMILES C1CCS(=O)(=O)C1
Properties
Chemical formula	C4H8O2S
Molar mass	120.17 g/mol
Appearance	clear colorless liquid
Density	1.261 g/cm3, liquid
Melting point	27.5 °C (81.5 °F; 300.6 K)
Boiling point	285 °C (545 °F; 558 K)
Solubility in water	miscible
Viscosity	0.01007 Pa·s at 25 °C
Structure
Dipole moment	4.35 D
Hazards
R-phrases	R22
S-phrases	S23, S24, S25
NFPA 704	1 2
Flash point	165 °C (329 °F; 438 K)
Autoignition temperature	528 °C (982 °F; 801 K)
Related compounds
Related compounds	Methylsulfonylmethane Tetrahydrothiophene Sulfolene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Tetrahydrothiophene
Sulfolene

Sulfolane (also tetramethylene sulfone, systematic name: 2,3,4,5-tetrahydrothiophene-1,1-dioxide) is an organosulfur compound, formally a cyclic sulfone, with the formula (CH₂)₄SO₂. It is a colorless liquid commonly used in the chemical industry as a solvent for extractive distillation and chemical reactions. Sulfolane was originally developed by the Shell Oil Company in the 1960s as a solvent to purify butadiene. Sulfolane is a polar aprotic solvent, and it is readily soluble in water.

Sulfolane is classified as a sulfone, a group of organosulfur compounds containing a sulfonyl functional group. The sulfone group is a sulfur atom doubly bonded to two oxygen atoms and singly bonded to two carbon centers. The sulfur-oxygen double bond is polar, conferring good solubility in water, while the four carbon ring provides non-polar stability. These properties allow it to be miscible in both water and hydrocarbons, resulting in its widespread use as a solvent for purifying hydrocarbon mixtures.

The original method developed by the Shell Oil Company was to first allow butadiene to react with sulfur dioxide via a cheletropic reaction to give sulfolene. This was then hydrogenated using Raney nickel as a catalyst to give sulfolane.