Sodium ethoxide, also known as sodium ethoxide, is an ionic organic compound with the molecular formula C2H5ONa, or NaOEt (Et = ethane). It is a white solid, although impure samples are yellow or brown. Soluble in polar solvents such as ethanol. It is commonly used as a strong base.

Sodium ethoxide is commonly used as a base in Claisen condensation [5] and malonate synthesis. [6] Sodium ethoxide can deprotonate the alpha position of an ester molecule to form an enolate, or an ester molecule can undergo a nucleophilic substitution called transesterification. If the starting material is an ethyl ester, transesterification is irrelevant since the product is the same as the starting material. In practice, the alcohol/alkoxide solvation mixture must be matched to the alkoxy component of the reacting ester to minimize the number of different products.

There are few reported procedures for the preparation of anhydrous solids. Instead, the material is usually prepared in ethanol solution. It is commercially available and is an ethanol solution. It is readily prepared in the laboratory by treating sodium metal with absolute ethanol:[3]

2C2H5OH + 2Na → 2C2H5ONa + H2

The reaction of sodium hydroxide with absolute ethanol is not completely converted to alkoxide.

Many alkoxides are prepared from sodium ethoxide by salt metathesis.

Sodium ethoxide reacts readily with water and carbon dioxide in the air. [7] This causes stored samples to degrade over time, even in the solid state. The physical appearance of degraded samples may not be apparent, but sodium ethoxide samples gradually darken on storage. Even freshly obtained commercial batches of sodium ethoxide have been reported to show varying degrees of degradation and become a major source of irreproducibility when used in the Suzuki reaction.

In humid air, NaOEt rapidly hydrolyzes to sodium hydroxide (NaOH). The transformation is not obvious, typical NaOEt samples are contaminated by NaOH.