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IUPAC name Ethane-1,2-dithiol
Other names Dimercaptoethane
CAS number 540-63-6
RTECS number KI3325000
Molecular formula C2H6S2
Molar mass 94.20 g/mol
Appearance Colorless liquid
Density 1.123 g/cm³, liquid
Melting point

-41 °C

Boiling point

146 °C
63 °C @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)
EU classification Toxic (T)
NFPA 704
R-phrases R10 R22
S-phrases S16
Flash point 50 °C
Related Compounds
Related thiols Ethanethiol; 1,3-Propanedithiol; 1,2-Benzenedithiol; Thiophenol
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

1,2-Ethanedithiol is an odorous, colorless liquid with the formula C2H4(SH)2. It is a common building block in organic synthesis and an excellent ligand for metal ions.

Applications in organic chemistry

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

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.


It can be prepared by the action of 1,2-dibromoethane on thiourea followed by hydrolysis.[2]


  1. ^ R. E. Conrow "Ethanedithiol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
  2. ^ Speziale, A. J. (1963). "Ethanedithiol". Org. Synth.; Coll. Vol. 4: 401. 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "1,2-Ethanedithiol". A list of authors is available in Wikipedia.
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