Alkyl Halides - Result Question 20
####20. The synthesis of alkyl fluorides is best accomplished by
(2015 Main)
(a) free radical fluorination
(b) Sandmeyer’s reaction
(c) Finkelstein reaction
(d) Swarts reaction
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Solution:
- 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.
$$ CH _3 Br+AgF \longrightarrow CH _3 F+AgBr $$
But, when aciton of $NaI /$ acetone takes place on alkyl chloride of bromide, alkyl iodide forms. This reaction is called ‘Finkelstein reaction’
$$ C _2 H _5 Cl \xrightarrow[\text { acetone }]{NaI} C _2 H _5 I+NaCl $$
Free redical fluorination is highly explosive reaction, so not preferred for the preparation of fluoride.
