What is a Finkelstein reaction?

In the Finkelstein reaction, alkyl iodides are prepared by the reaction of alkyl chlorides/bromides with NaI in dry acetone.

Finkelstein reaction

The Finkelstein reaction is a Substitution Nucleophilic Bimolecular reaction (SN₂ Reaction) involves the exchange of halogen atom. It is named after Hans Finkelstein, a German chemist.

• It is an organic reaction that uses an alkyl halide exchange into another alkyl halide through a reaction wherein the metal halide salt is used.
• This reaction takes place at an equilibrium process by taking the advantage of poor acetone solubility in metal halide salt that is newly formed.

Example of Finkelstein reaction

Finkelstein’s reactionworks good with the primary halides but better with α-carbonyl halides and allyl benzyl.

The bromoethane can be converted to iodoethane

CH₃CH₂-Br + NaI →CH₃CH₂-I+ NaBr