Question

Which of the following alkyl halide could be successfully used to synthesize Grignard reagent ?

• A. $\left(I\right)$
• B. $\left(II\right)$
• C. $\left(III\right)$
• D. $\left(IV\right)$

Answer 1

Answer: (B)

$\left(II\right)$

Grignard reagent is a powerful base. Because of this it cannot be used as nucleophile on compounds which contain acidic hydrogens. If it is used then will act as a base and deprotonate the acidic hydrogen rather than act as a nucleophile and attack the carbonyl. Due to the presence of acidic hydrogen alcohols, amides, $1^o$amines, $2^o$ amines, carboxylic acids, and terminal alkynes can not synthesize grignard reagent.