Question

The synthesis of alkyl fluorides is best accomplised by:

• A. Free radical fluorination
• B. Sandmeyer's reaction
• C. Finkelstein reaction
• D. Swarts reaction

Answer 1

The correct option is D Swarts reaction

Alkyl fluorides can be prepared by action of mercurous fluoride or antimony trifluorides (inorganic fluorides) on corresponding alkyl halide. This reaction is known as Swarts reaction.
$C{H}_{3}Br+AgF\to \underset{\text{Methyl fluoride}}{C{H}_{3}F}+AgBr$

But, when action of $NaI$/acetone takes place on alkyl chloride of bromide, alkyl iodide forms. This reaction is called 'Finkelstein reaction'.
$C_2{H}_{5}Cl\underset{\text{acetone}}{\overset{NaI}{\to }}{C}_2{H}_{5}I+NaCl$

Free radical fluorination is highly explosive reaction, so not preferred for the preparation of fluoride.