1,2-Ethanedithiol
| 1,2-Ethanedithiol | |
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Ethane-1,2-dithiol |
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Other names
Dimercaptoethane |
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| Identifiers | |
| CAS number | 540-63-6  |
| ChemSpider | 13865015 |
| UNII | 92T634FLAR |
| RTECS number | KI3325000 |
| Jmol-3D images | Image 1 |
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| 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
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| Flash point | 50 °C |
| Related compounds | |
| Related thiols | Ethanethiol; 1,3-Propanedithiol; 1,2-Benzenedithiol; Thiophenol |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 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.
[edit] Preparation
1,2-Ethanedithiol is commercially available. It can be prepared by the action of 1,2-dibromoethane on thiourea followed by hydrolysis.[1]
[edit] 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]
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- 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.
[edit] References
- ^ Speziale, A. J. (1963), "Ethanedithiol", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0401; Coll. Vol. 4: 401
- ^ R. E. Conrow "Ethanedithiol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289
