Question

What is the name of the following reaction ?
$C{H}_{3}C{H}_{2}C{H}_{2}Br\underset{dryacetone}{\overset{NaI}{\to }}C{H}_{3}C{H}_{2}C{H}_{2}I$

• A. Sandmeyer Reaction
• B. Gatterman Reaction
• C. Finkelstein Reaction
• D. Swarts Reaction

Answer 1

The correct option is C Finkelstein Reaction

The Finkelstein reaction, named after the German chemist Hans Finkelstein, is an $S{N}^2$ reaction (Substitution Nucleophilic Bimolecular reaction) that involves the exchange of one halogen atom for another. Halide exchange is an equilibrium reaction, but the reaction can be driven to completion by exploiting the differential solubility of halide salts, or by using a large excess of the halide salt.
R-X + X′− ⇌ R-X′ + X−
The classic Finkelstein reaction is the conversion of an alkyl chloride or an alkyl bromide to an alkyl iodide by treatment with a solution of sodium iodide in acetone. Sodium iodide is soluble in acetone and sodium chloride and sodium bromide are not. The reaction is driven toward products by mass action due to the precipitation of the insoluble salt. For example, bromoethane can be converted to iodoethane:
$C{H}_{3}C{H}_{2}C{H}_{2}Br\left(acetone\right)+NaI\left(acetone\right)\to C{H}_{3}C{H}_{2}C{H}_{2}I\left(acetone\right)+NaBr\left(s\right)$