Potassium ethoxide, also known as potassium ethanolate, is an off-white or yellow powder with the chemical formula of C
2H
5KO. Potassium ethoxide contains an ethoxide ion, the conjugate base of ethanol, which makes this compounds strongly basic. It hydrolyzes to yield ethanol and potassium hydroxide.
Uses
Potassium ethoxide is used as a strong base, similar to
sodium methoxide, sodium and
potassium methoxide
Potassium methoxide is the alkoxide of methanol with the counterion potassium and is used as a strong base and as a catalyst for transesterification, in particular for the production of biodiesel.
Preparation
The preparation of potassium methox ...
s, and
potassium tert-butoxide
Potassium ''tert''-butoxide is the chemical compound with the formula K+(CH3)3CO−. This colourless solid is a strong base (pKa of conjugate acid around 17), which is useful in organic synthesis. It exists as a tetrameric cubane-type cluster ...
. Catalytic amounts of potassium ethoxide in ethanol can be used to perform
transesterification
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can ...
reactions that yield ethyl esters. Sodium or potassium ethoxide is also a suitable base for the
malonic ester synthesis
The malonic ester synthesis is a chemical reaction where diethyl malonate or another ester of malonic acid is alkylated at the carbon alpha (directly adjacent) to both carbonyl groups, and then converted to a substituted acetic acid. The major ...
where
diethyl malonate
Diethyl malonate, also known as DEM, is the diethyl ester of malonic acid. It occurs naturally in grapes and strawberries as a colourless liquid with an apple-like odour, and is used in perfumes. It is also used to synthesize other compounds su ...
is used, since any transesterification reaction does not result in ester scrambling.
Safety
Potassium ethoxide is stable, but also both flammable and corrosive. The compound reacts vigorously with water. If the compound comes into contact with damp air, it may lead to the heating and ignition of the solid powder. It must be kept separated from air, moisture, water, acids, oxidizing agents, and reducing agents.
n.pag. CasLAb. Web. 19 Oct 2012. . It can also cause severe skin burns.
n.pag. chemexper. Web. 19 Oct 2012. .
References
Ethoxides
Potassium compounds