# What is the mechanism of the reaction of NaI in acetone with an alkyl halide?

Jan 10, 2016

#### Answer:

This operates by the ${S}_{N} 2$ mechanism. The iodide ion is a reasonably good nucleophile, and adds as ${I}^{-}$

#### Explanation:

$R - C l + N {a}^{+} {I}^{-}$ $\rightarrow$ $R - I + N a C l \downarrow$

Because sodium iodide is much more soluble than sodium chloride in acetone, when you do this you see a glassy precipitate of sodium chloride in the acetone. I think there is a named organic spot test for this reaction (its name escapes me at the moment, I should not have finished that bottle of wine last night!). If you have time in an organic laboratory it would be worth your while to do this reaction in a small test tube so you can notice the turbidity of the sodium chloride when it precipitates.