Chapter 12.4, Problem 7P

Interpretation Introduction

Interpretation: Among the given alky halides, the one that could be successfully used to prepare a Grignard reagent have to be found.

Concept Introduction:

Grignard reagent: Alkyl, vinyl, or aryl-magnesium halides are called as Grignard reagents.

The chemical formula of the Grignard reagent is $\text{RMgX}$.

$\begin{array}{l}\text{Where}\\ \text{R-}\text{Alkyl}\text{or}\text{aryl or}\text{vinyl}\\ \text{X}\text{-}\text{Halogens}\text{such}\text{as}\text{Br,Cl}\text{or}\text{I}\end{array}$

Grignard reagents are very good nucleophiles and the alkyl group in it act as if it is a carbanion. So the alkyl part remains as nucleophilic part of the Grignard reagent whereas the metallic magnesium part remains as electrophilic part of it.

Grignard reagent preparation:

Example:

The given reaction is the preparation of Grignard reagent by treating alkyl halide with magnesium shavings being stirred in diethyl ether. In this reaction a magnesium atom is being inserted between the carbon of the ethyl group and the halogen atom (bromine atom).