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Ethane-1,2-dithiol

Ethane-1,2-dithiol, also known as EDT,[1] 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

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.[2]

Reactions

1,2-Ethanedithiol is a weak acid, typical of alkyl thiols. In the presence of base and an alkylating agent, 1,2-ethanedithiol converts to thioethers:

HS(CH2)2SH + 2 NR3 + 2 R'I → R'S(CH2)2SR' + 2 [R3NH]I

Oxidation of 1,2-ethanedithiol gives a series of oligomers, including the cyclic bis(disulfide).[3]

As a 1,2-dithiol, this compound reacts with aldehydes and ketones to give 1,3-dithiolanes, which can be useful intermediates.[4]

Protecting a carbonyl group by converting it to a 1,3-dithiolane, using ethane-1,2-dithiol
Protecting a carbonyl group by converting it to a 1,3-dithiolane, using ethane-1,2-dithiol

Other 1,2- and 1,3-dithiols give related 1,3-dithiolanes (five-membered) and 1,3-dithianes (six-membered rings). Diols such as ethylene glycol undergo analogous reactions to give 1,3-dioxolanes. 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 has been used as a scavenger in peptide cleavage synthesis.[citation needed]

Like 1,3-propanedithiol, 1,2-ethanedithiol readily forms metal thiolate complexes. Illustrative is the synthesis of the derivative diiron ethanedithiolate hexacarbonyl upon reaction with triiron dodecacarbonyl:[5]

Fe3(CO)12 + C2H4(SH)2 → Fe2(S2C2H4)(CO)6 + H2 + Fe(CO)5 + CO

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. 42 (1): 58–63. doi:10.1111/j.1399-3011.1993.tb00350.x. ISSN 1399-3011. PMID 8103765.
  2. ^ Speziale, A. J. (1963). "Ethanedithiol". Organic Syntheses; Collected Volumes, vol. 4, p. 401.
  3. ^ Goodrow, Marvin H.; Olmstead, Marilyn M.; Musker, W.Kenneth (1982). "Preparation, Properties and Crystal Structure of 1,2,5,6-Tetrathiacyclooctane". Tetrahedron Letters. 23 (32): 3231–3234. doi:10.1016/S0040-4039(00)87577-2.
  4. ^ R. E. Conrow "Ethanedithiol" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. doi:10.1002/047084289X
  5. ^ Hogarth, Graeme (2023). "An Unexpected leading role for [Fe2(CO)6(μ-PDT)] in our Understanding of [FeFe]-H2ases and the Search for Clean Hydrogen Production". Coordination Chemistry Reviews. 490. doi:10.1016/j.ccr.2023.215174.