1,2-Ethanedithiol

1,2-Ethanedithiol
Identifiers
CAS number 540-63-6 Y
ChemSpider 13865015 Y
UNII 92T634FLAR Y
RTECS number KI3325000
Jmol-3D images Image 1
Properties
Molecular formula C2H6S2
Molar mass 94.2 g mol−1
Appearance Colorless liquid
Density 1.123 g/cm³
Melting point

-41 °C, 232 K, -42 °F

Boiling point

146 °C, 419 K, 295 °F (46 mmHg)

Solubility in water Slightly sol
Solubility in other solvents Good solubility in
most organic solvents
Acidity (pKa) ~11
Refractive index (nD) 1.5589 (D-line, 25 °C)
Hazards
EU classification Toxic (T)
R-phrases R10 R22
S-phrases S16
NFPA 704
2
2
0
Flash point 50 °C
Related compounds
Related thiols Ethanethiol; 1,3-Propanedithiol; 1,2-Benzenedithiol; Thiophenol
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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 commercially available. It can 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.

References

  1. ^ Speziale, A. J. (1963), "Ethanedithiol", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0401 ; Coll. Vol. 4: 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