Chemistry:Potassium thioacetate

Short description: Organosulfur compound (CH3COS- K+)

Potassium thioacetate

Identifiers
CAS Number	10387-40-3 Y
3D model (JSmol)	Interactive image
ChemSpider	74542
EC Number	233-848-7
MeSH	C005732
PubChem CID	4463282
UNII	ZY58K327HN Y
InChI InChI=1S/C2H4OS.K/c1-2(3)4;/h1H3,(H,3,4);/q;+1/p-1 Key: AFNBMGLGYSGFEZ-UHFFFAOYSA-M
SMILES CC(=O)[S-].[K+]
Properties
Chemical formula	C2H3KOS
Molar mass	114.21
Appearance	white solid
Solubility in water	good
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium thioacetate is an organosulfur compound and a salt with the formula CH
3COS−
K+
. This white, water-soluble solid is used as a reagent for preparing thioacetate esters and other derivatives.

Synthesis and reactions

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

$\mathrm{C}\mathrm{H}{\phantom{A}}_3\mathrm{C}\mathrm{O}\mathrm{C}\mathrm{l}+2\mathrm{K}\mathrm{S}\mathrm{H}⟶\mathrm{K}\mathrm{C}\mathrm{l}+\mathrm{C}\mathrm{H}{\phantom{A}}_3\mathrm{C}\mathrm{O}\mathrm{S}\mathrm{K}+\mathrm{H}{\phantom{A}}_2\mathrm{S}$

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):

$\mathrm{C}\mathrm{H}{\phantom{A}}_3\mathrm{C}\mathrm{O}\mathrm{S}\mathrm{K}+\mathrm{R}\mathrm{X}⟶\mathrm{C}\mathrm{H}{\phantom{A}}_3\mathrm{C}\mathrm{O}\mathrm{S}\mathrm{R}+\mathrm{K}\mathrm{X}$

Hydrolysis of these esters affords thiols:

$\mathrm{C}\mathrm{H}{\phantom{A}}_3\mathrm{C}\mathrm{O}\mathrm{S}\mathrm{R}+\mathrm{H}{\phantom{A}}_2\mathrm{O}⟶\mathrm{C}\mathrm{H}{\phantom{A}}_3\mathrm{C}\mathrm{O}{\phantom{A}}_2\mathrm{H}+\mathrm{R}\mathrm{S}\mathrm{H}$

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:

$\mathrm{H}{\phantom{A}}_3\mathrm{C}(\mathrm{C}\mathrm{H}{\phantom{A}}_2){\phantom{A}}_3\mathrm{O}\mathrm{M}\mathrm{s}+\mathrm{K}\mathrm{S}\mathrm{A}\mathrm{c}⟶\mathrm{H}{\phantom{A}}_3\mathrm{C}(\mathrm{C}\mathrm{H}{\phantom{A}}_2){\phantom{A}}_3\mathrm{S}\mathrm{A}\mathrm{c}+\mathrm{K}\mathrm{O}\mathrm{M}\mathrm{s}$

$\mathrm{H}{\phantom{A}}_3\mathrm{C}(\mathrm{C}\mathrm{H}{\phantom{A}}_2){\phantom{A}}_3\mathrm{S}\mathrm{A}\mathrm{c}+\mathrm{H}\mathrm{S}\mathrm{M}\mathrm{e}⟶\mathrm{H}{\phantom{A}}_3\mathrm{C}(\mathrm{C}\mathrm{H}{\phantom{A}}_2){\phantom{A}}_3\mathrm{S}\mathrm{H}+\mathrm{M}\mathrm{e}\mathrm{S}\mathrm{A}\mathrm{c}$