Chapter 18, Problem 18.23P

(a)

Interpretation Introduction

Interpretation:

The structural formula for the principal product formed when benzamide is treated with the given reagent has to be drawn.

Concept introduction:

The normal reaction of an amide with water does not give good yield of product. As amides are least reactive carboxylic acid derivatives so to increase the reactivity of amides a mineral acid is added. The addition of acid increases the reactivity of amide by making more electrophilic carbonyl carbon and it also helps in the elimination of amine part from amide via protonating the amine group during reaction and make it a good leaving group.

The reaction of water and amides in presence of acid gives a carboxylic acid as a product. The reaction equation is written as,

The reactivity of amide also depends upon the leaving tendency of amine part from acyl group. The weaker the base better will be the leaving group. The basicity of amines is decreased by decreasing the electron density from nitrogen atom of amine.

(b)

Interpretation Introduction

Interpretation:

The structural formula for the principal product formed when benzamide is treated with the given reagent has to be drawn.

Concept introduction:

Amide hydrolysis in aqueous base:

A carboxylate salt and ammonia or an amine will be the product of amide hydrolysis in aqueous base.

For each mole of amide, one mole of base is required.

(c)

Interpretation Introduction

Interpretation:

The structural formula for the principal product formed when benzamide is treated with the given reagent has to be drawn.

Concept introduction:

$LiAl{H}_4$ is a powerful reducing agent which reduces amides into ${\text{1}}^{\text{°}}\text{,}{\text{2}}^{\text{°}}\text{,}\text{or}{\text{3}}^{\text{°}}$ amines depending on the degree of substitution of the amide.