Finkelstein Reaction (R-Br + NaI → R-I + NaBr↓ (dry acetone))
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R-Br + NaI → R-I + NaBr↓ (dry acetone)
What each symbol means
| Symbol | What it stands for |
|---|---|
| R | Alkyl group (primary works best) |
| NaI | Sodium iodide — source of iodide nucleophile |
| NaBr↓ | Precipitates out — Le Chatelier shift |
| dry acetone | Solvent that dissolves NaI but not NaBr/NaCl (drives equilibrium forward) |
When to use this
SN2 mechanism; dry acetone is critical because NaBr/NaCl are insoluble in it (precipitate), shifting equilibrium to product side. Works best with primary alkyl halides.