Chapter 11, Problem 48P

(a)

Interpretation Introduction

Interpretation:

To identify which of the given reaction is not feasible.

Concept introduction:

The carboxylic acid and its derivatives undergo nucleophilic acyl substitution reaction. The incoming group is called as a nucleophile and the substituent that departs from a molecule is known as leaving the group. If the attacking group is a good base or poor leaving group as compared to the substituent that is already present in the tetrahedral intermediate than attacking group will replace the existing substituent or good leaving group and reaction will be feasible.

(b)

Interpretation Introduction

Interpretation:

To identify the reactions which are not feasible in the above part of the question can be made feasible by adding an acid catalyst.

Concept introduction:

The aminolysis reaction and the hydrolysis of ester can be made feasible by the addition of acid catalyst in the reaction mixture.

The acid catalyst first protonates the carbonyl oxygen thus increses the electrophillitcity of the carbonyl carbon and also protonates the nitogen atom making it good leaving group. Thus, the rate of reaction increases.