Why does the reactivity of `NH_(2)` get reduced in acetanilide ?

Explanation

To understand why the reactivity of the `NH2` group is reduced in acetanilide, we can break down the explanation into several steps:

### Step 1: Structure of Acetanilide
Acetanilide is an organic compound with the following structure:
- It consists of an aniline (benzene ring with an `NH2` group) where the `NH2` group is acetylated (attached to a carbonyl group `C=O` and a methyl group `CH3`).
- The structure can be represented as:
```
O
...