How is 2,4-dinitrophenylhydrazine prepared from chlorobenzene?

Explanation

To prepare 2,4-dinitrophenylhydrazine from chlorobenzene, we will follow a series of steps involving nitration and subsequent reactions. Here’s a step-by-step breakdown of the process:

### Step 1: Nitration of Chlorobenzene
1. **React chlorobenzene with a nitrating mixture**:
- Prepare a nitrating mixture by mixing concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4).
- Add chlorobenzene (C6H5Cl) to this mixture. The chlorine atom in chlorobenzene is a para-directing group, which means that the nitro group (NO2) will preferentially attach to the para position relative to the chlorine atom.
- The reaction will yield 4-chloronitrobenzene (C6H4Cl(NO2)) and some ortho-nitro products as well.

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