Ethane-1,2-dithiol explained

Ethane-1,2-dithiol, also known as EDT,[1] is a colorless liquid with the formula CH(SH). 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

Ethane-1,2-dithiol is made 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.

Applications

As a 1,2-dithiol, 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]

CH(SH) + RR'CO → CHSCRR' + HO

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-dioxolanes 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.

1,2-Ethanedithiol is commonly used as a scavenger in peptide cleavage synthesis.

See also

References

  1. Choi. H.. Aldrich. J.v.. 1993-07-01. Comparison of methods for the Fmoc solid-phase synthesis and cleavage of a peptide containing both tryptophan and arginine. International Journal of Peptide and Protein Research. en. 42. 1. 58–63. 10.1111/j.1399-3011.1993.tb00350.x. 8103765. 1399-3011.
  2. R. E. Conrow "Ethanedithiol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York.