Question

Identify the name of the following reaction
${ CH }_{ 3 }{ Br+NaI\rightarrow CH }_{ 3 }{ I+NaBr }$
A.Finkelstein reaction
B.Gattermann reaction
C.Sandmeyer reaction
D.Wurtz reaction

Answer 1

Hint:
A name reaction is a chemical reaction named after its discoverers or developers. Among the tens of thousands of organic reactions that are known, hundreds of such reactions are well-known enough to be named after people.

Complete step-by-step answer:

A.Finkelstein reaction: The Finkelstein reaction is an ${ S }_{ N }^{ 2 }$ reaction that involves the exchange of lighter halogen atoms by heavier halogen atoms from alkyl halide. Halide exchange is an equilibrium reaction.
${ CH }_{ 3 }{ Br+NaI\rightarrow CH }_{ 3 }{ I+NaBr }$

The solubility of sodium chloride or sodium bromide in acetone is much less than the solubility of sodium iodide. During the reaction of an alkyl chloride or bromide with sodium iodide in acetone, the formed sodium chloride or bromide precipitates out from the solution and is thus removed from equilibrium and drives the reaction to completion. Hence Finkelstein’s reaction is usually employed to prepare alkyl iodides which are otherwise difficult to prepare directly.
B. Gattermann reaction: The Gattermann reaction is the modification of the Sandmeyer reaction in which benzene diazonium chloride is treated with Cu powder and a halogen acid to form aryl halide.
${ C }_{ 6 }{ H }_{ 5 }{ { N }_{ 2 }^{ + }Cl }^{ - }{ \rightarrow C }_{ 6 }{ H }_{ 5 }{ Cl+N }_{ 2 }$

C. Sandmeyer reaction: Sandmeyer’s Reaction is a reaction used for the conversion of diazonium salt to aryl halide. It is applicable to primary aromatic amines.

D. Wurtz reaction: Two molecules of alkyl halides (same or different) react with sodium in the presence of dry ether to form alkanes. This reaction is known as the Wurtz reaction and is generally applied to prepare symmetrical alkanes with more carbon atoms.
${ R-X+2Na+R-X\rightarrow R-R+2NaX }$

As we see that the given reaction is a Finkelstein reaction.
The correct option is A.

Note:
The possibility to make a mistake is that you may choose option D. But Wurtz’s reaction is used to prepare alkanes and in the given reaction aryl halide is formed.