Potassium t-butoxide is commercially available as a solution and as a solid, but it is often generated in situ for laboratory use because samples are so sensitive and older samples are often of poor quality. It is prepared by the reaction of dry tert-butanol with potassium metal.[1] The solid is obtained by evaporating these solutions followed by heating the solid. The solid can be purified by sublimation at 220 ¡ãC and 1 mm Hg.

The tert-butoxide species is itself useful as a strong, non-nucleophilic base in organic chemistry. It is not as strong as amide bases, e.g. lithium diisopropylamide, but stronger than potassium hydroxide. Its steric bulk inhibits the group from participating in nucleophilic addition, such as in a Williamson ether synthesis or an SN2 reaction. Substrates that are deprotonated by potassium t-butoxide include terminal acetylenes and active methylene compounds. It is useful in dehydrohalogenation reactions.

Many modifications have been reported that influence the reactivity of this reagent. The compound adopts a complex cluster structure (the picture to the right is a simplified cartoon), and additives that modify the cluster affect the reactivity of the reagent. For example, both DMSO, hexamethylphosphoramide (HMPA), and 18-crown-6 interact with the potassium center, enhancing the basicity of the butoxide. Schlosser's base, a mixture of the alkoxide and an alkyl lithium compound, is a related but stronger base.