Which sequence of steps will be able to produce `3, 3'-`dinitro-biphenyl from benzene?

Options

A. `HNO_3 // H_(2) SO_(4) , CI_(2) // FeCI_3 `, Na/ether
B. `CI_2// FeCI_3, HNO_3 //H_(2) SO_(4)`, Na/ether
C. `CI_2//FeCI_3, H_(2) SO_(4)`, Na/ether
D. `I_(2)//HIO_3, CI_2//FeCI_3, C_6 H_5 NO_2`

Explanation

To synthesize `3,3'-dinitro-biphenyl` from benzene, we can follow these steps:

### Step 1: Nitration of Benzene
- **Reaction:** Treat benzene with a mixture of concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4).
- **Product:** This will introduce a nitro group (-NO2) at the ortho or para position of benzene, resulting in nitrobenzene.

### Step 2: Electrophilic Aromatic Substitution (Halogenation)
- **Reaction:** Next, perform a halogenation by treating nitrobenzene with chlorine (Cl2) in the presence of a Lewis acid catalyst like iron(III) chloride (FeCl3).
- **Product:** The chlorine will substitute at the meta position relative to the nitro group, resulting in `3-chloro-nitrobenzene`.

### Step 3: Formation of Aryl Halide
- **Product:** Now we have an aryl halide, `3-chloro-nitrobenzene`.

### Step 4: Coupling Reaction (Friedel-Crafts Coupling)
- **Reaction:** Perform a Friedel-Crafts coupling by reacting `3-chloro-nitrobenzene` with another benzene in the presence of sodium (Na) or an ether solvent.
- **Product:** This will yield `3,3'-dinitro-biphenyl`.

### Final Product
- The final product after these reactions is `3,3'-dinitro-biphenyl`.

### Summary of Steps:
1. Nitration of benzene → nitrobenzene
2. Halogenation of nitrobenzene → 3-chloro-nitrobenzene
3. Friedel-Crafts coupling → 3,3'-dinitro-biphenyl

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