Question

Outline the mechanism of the acid-catalyzed hydrolysis of p-nitroacetanilide to yield p-nitroaniline?

Answer 1

The acid-catalyzed hydrolysis of p-nitroacetanilide to yield p-nitroaniline involves several steps. The acid protonates the carbonyl oxygen, making it more electrophilic. Water then attacks the electrophilic carbon, leading to the formation of a tetrahedral intermediate. The amide intermediate undergoes rearrangement, and an acid-base reaction occurs, resulting in the formation of p-nitroaniline.

Step-by-step explanation:

In the acid-catalyzed hydrolysis of p-nitroacetanilide to yield p-nitroaniline, the mechanism involves several steps:

1. The acid protonates the carbonyl oxygen, making it more electrophilic.
2. The nucleophile, water, attacks the electrophilic carbonyl carbon, leading to the formation of a tetrahedral intermediate.
3. The tetrahedral intermediate loses a proton, resulting in the formation of an amide intermediate.
4. The amide intermediate undergoes a rearrangement, with the p-nitro group migrating to the nitrogen atom.
5. An acid-base reaction occurs, where water donates a proton to the amine, resulting in the formation of p-nitroaniline.

The acid serves as a catalyst in this mechanism, as it is consumed in one step but regenerated in another step. By providing an acidic environment, the acid accelerates the rate-determining steps of the reaction.