1,2-Ethanedithiol

1,2-Ethanedithiol
Names
IUPAC name
Ethane-1,2-dithiol
Other names
Dimercaptoethane
1,2-Ethanedithiol
Identifiers
540-63-6 Yes
ChemSpider 13865015 Yes
Jmol-3D images Image
RTECS number KI3325000
UNII 92T634FLAR Yes
Properties
Molecular formula
 C2H6S2
Molar mass 94.20 g·mol−1
Appearance Colorless liquid
Density 1.123 g/cm³
Melting point −41 °C (−42 °F; 232 K)
Boiling point 146 °C (295 °F; 419 K) 46 mmHg
Slightly sol
Solubility in other solvents Good solubility in
most organic solvents
Acidity (pKa) ~11
1.5589 (D-line, 25 °C)
Hazards
EU classification Toxic (T)
R-phrases R10 R22
S-phrases S16
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity (yellow): no hazard code Special hazards (white): no codeNFPA 704 four-colored diamond
2
2
Flash point 50 °C (122 °F; 323 K)
Related compounds
Related thiols
1,1-Ethanedithiol; Ethanethiol; 1,3-Propanedithiol; 1,2-Benzenedithiol; Thiophenol
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

1,2-Ethanedithiol is a colorless liquid with the formula C2H4(SH)2. It has a very characteristic odor which is compared by many people to rotten cabbage. It is a common building block in organic synthesis and an excellent ligand for metal ions.

Preparation

1,2-Ethanedithiol is prepared commercially by the reaction of 1,2-dichloroethane with aqueous sodium bisulfide. In the laboratory, it can also be prepared by the action of 1,2-dibromoethane on thiourea followed by hydrolysis.[1]

Applications

This compound is widely used in organic chemistry because it reacts with aldehydes and ketones to give 1,3-dithiolanes, which are useful intermediates. [2]

C2H4(SH)2 + RR'CO → C2H4S2CRR' + H2O

Other 1,2- and 1,3-dithiols undergo this reaction to give related 1,3-dithiolanes and 1,3-dithianes (six-membered rings). Diols such as ethylene glycol undergo analogous reactions to 1,3-dioxalanes and 1,3-dioxanes. One distinguishing feature of the dithiolanes and dithianes derived from aldehydes is that the methyne group can be deprotonated and the resulting carbanion alkylated.

See also

References

  1. ↑ Speziale, A. J. (1963). "Ethanedithiol". Org. Synth.; Coll. Vol. 4, p. 401
  2. ↑ R. E. Conrow "Ethanedithiol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289