The Wurtz reaction is an organic chemical coupling reaction developed by Charles Adolphe Wurtz, used in organic chemistry and organometallic chemistry for the formation of alkanes. In this reaction, two different alkyl halides are coupled to yield a longer alkane chain with the help of sodium and dry ether solution. The reaction proceeds by an initial metal-halogen exchange, which is described with the following idealized stoichiometry: R−X + 2 M → RM + MX. The carbon-carbon bond is formed in a nucleophilic substitution reaction in this reaction mechanism, which can be broken down into the following 3 steps:
-
Formation of free radicals: The alkyl halides are converted into free radicals by the action of sodium metal.
-
Formation of sodium alkyl: The free radicals combine with sodium to form sodium alkyl.
-
Coupling of sodium alkyl: The sodium alkyls combine to form the desired alkane.
The Wurtz reaction is useful for the preparation of symmetrical alkanes. However, the reaction is intolerant of a range of functional groups which would be attacked by sodium. For similar reasons, the reaction is conducted in unreactive solvents such as ethers.
