Chemistry:Potassium thioacetate

From HandWiki
Short description: Organosulfur compound (CH3COS- K+)
Potassium thioacetate
KSAc.png
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 233-848-7
MeSH C005732
UNII
Properties
C2H3KOS
Molar mass 114.21
Appearance white solid
good
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Tracking categories (test):

Potassium thioacetate is an organosulfur compound and a salt with the formula CH
3
COS
K+
. This white, water-soluble solid is used as a reagent for preparing thioacetate esters and other derivatives.[1]

Synthesis and reactions

Potassium thioacetate, which is commercially available, can be prepared by combining acetyl chloride and potassium hydrogen sulfide:

[math]\ce{ CH3COCl + 2 KSH -> KCl + CH3COSK + H2S }[/math]

It arises also by the neutralization of thioacetic acid with potassium hydroxide.

Use in preparation of thiols

In a common application, potassium thioacetate is combined with alkylating agents to give thioacetate esters (X = halide):

[math]\ce{ CH3COSK + RX -> CH3COSR + KX }[/math]

Hydrolysis of these esters affords thiols:

[math]\ce{ CH3COSR + H2O -> CH3CO2H + RSH }[/math]

The thioacetate esters can also be cleaved with methanethiol in the presence of stoichiometric base, as illustrated in the preparation of pent-4-yne-1-thiol:[2]

[math]\ce{ H3C(CH2)3OMs + KSAc -> H3C(CH2)3SAc + KOMs }[/math]
[math]\ce{ H3C(CH2)3SAc + HSMe -> H3C(CH2)3SH + MeSAc }[/math]

References

  1. Zongjun Qiao and Xuefeng Jiang "Potassium Thioacetate" e-EROS Encyclopedia Of Reagents For Organic Synthesis, 2014. doi:10.1002/047084289X.rn01737
  2. Matteo Minozzi; Daniele Nanni; Piero Spagnolo (2008). "4-Pentyne-1-thiol". EEROS. doi:10.1002/047084289X.rn00855. ISBN 978-0-471-93623-7.