4,4-Dinitrodiphenyl is obtained when

Options

A. 4-Nitrochlorobenzene is heated with Na/ether
B. 4-Nitrolodobenzene is heated with copper powder in a seated tube
C. diphenyl is heated with a mixture of conc. `HNO_(3)` and conc. `H_(2)SO_(4)`
D. nitrobenzene is treated with 4-nitrochlorobenzene in presence of anhyd. `AlCl_(3)`

Answer

To determine how 4,4-Dinitrodiphenyl is obtained, we can analyze the reactions mentioned in the video transcript step by step.

### Step 1: Understanding the Reactions
We have several reactions that can lead to the formation of 4,4-Dinitrodiphenyl. The key reactions mentioned are:

1. **Wurtz Reaction**:
- Reaction of 4-nitrochlorobenzene with sodium in ether.
- This reaction involves the coupling of two aryl halides.

2. **Ullmann Reaction**:
- Reaction of 4-nitroiodobenzene with copper powder.
- This reaction also involves the coupling of two aryl halides.

3. **Nitration Reaction**:
- Reaction of diphenyl with concentrated nitric acid and concentrated sulfuric acid.
- This reaction introduces nitro groups onto the diphenyl compound.

4. **Friedel-Crafts Reaction**:
- Reaction of nitrobenzene with 4-nitrochlorobenzene in the presence of anhydrous AlCl3.
- However, this reaction does not occur due to the electron-withdrawing nature of the nitro group.

### Step 2: Analyzing Each Reaction

1. **Wurtz Reaction**:
- **Reactants**: 4-nitrochlorobenzene (2 moles) + Sodium (2 moles) + Ether.
- **Products**: 4,4-Dinitrodiphenyl + 2 moles of NaCl.
- This reaction successfully produces 4,4-Dinitrodiphenyl.

2. **Ullmann Reaction**:
- **Reactants**: 4-nitroiodobenzene (2 moles) + Copper powder.
- **Products**: 4,4-Dinitrodiphenyl + Cuprous and Cupric iodide.
- This reaction also successfully produces 4,4-Dinitrodiphenyl.

3. **Nitration Reaction**:
- **Reactants**: Diphenyl + Concentrated HNO3 + Concentrated H2SO4.
- **Products**: 4,4-Dinitrodiphenyl.
- This reaction successfully produces 4,4-Dinitrodiphenyl.

4. **Friedel-Crafts Reaction**:
- **Reactants**: Nitrobenzene + 4-nitrochlorobenzene + Anhydrous AlCl3.
- This reaction does not occur because the nitro group is an electron-withdrawing group, which decreases the electron density needed for electrophilic substitution.

### Conclusion
The reactions that lead to the formation of 4,4-Dinitrodiphenyl are:
- Wurtz Reaction (Option A)
- Ullmann Reaction (Option B)
- Nitration of Diphenyl (Option C)

The Friedel-Crafts reaction (Option D) does not lead to the formation of 4,4-Dinitrodiphenyl.

### Final Answer
The correct options that lead to the formation of 4,4-Dinitrodiphenyl are A, B, and C.

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