The reaction of 1-phenylpropane with limited amount of chlorine in the presence of light gives mainly .

Options

A. 4-chloropropylbenzene
B. 1-chloro-1-phenylpropane
C. 3-chloro-1-phenylpropane
D. 2-chloro-1-phenylpropane

Answer

To solve the question regarding the reaction of 1-phenylpropane with limited amounts of chlorine in the presence of light, we can follow these steps:

### Step 1: Identify the Reactants
The reactant is 1-phenylpropane, which has the following structure:
- It consists of a propane chain (3 carbon atoms) with a phenyl group (C6H5) attached to the first carbon.

### Step 2: Understand the Reaction Conditions
The reaction occurs in the presence of light, which indicates that it will proceed via a free radical mechanism. This is typical for halogenation reactions under these conditions.

### Step 3: Determine Possible Free Radicals
When 1-phenylpropane reacts with chlorine, several free radicals can form:
1. **Cleavage of the methyl (CH3) bond**: This forms a primary free radical.
2. **Cleavage of the CH bond adjacent to the phenyl group**: This forms a secondary free radical.
3. **Cleavage of the CH bond on the other side of the propane chain**: This also forms a secondary free radical.

### Step 4: Analyze Stability of Free Radicals
The stability of the free radicals formed is crucial:
- **Primary free radical** (from methyl cleavage) is the least stable.
- **Secondary free radicals** (from cleavage adjacent to the phenyl group) are more stable than primary.
- Among the secondary free radicals, the one that can resonate with the phenyl group will be the most stable due to resonance and hyperconjugation effects.

### Step 5: Identify the Most Stable Free Radical
The secondary free radical formed by the cleavage of the CH bond adjacent to the phenyl group is the most stable due to resonance with the phenyl ring.

### Step 6: Reaction with Chlorine Radical
In the presence of light, chlorine (Cl2) will undergo homolytic cleavage to form chlorine radicals (Cl•). The stable free radical formed from 1-phenylpropane will react with the chlorine radical to form the product.

### Step 7: Determine the Product
The reaction of the stable secondary free radical with a chlorine radical will lead to the formation of:
- **1-chloro-1-phenylpropane** (where chlorine is added to the carbon that was part of the free radical).

### Conclusion
Thus, the main product of the reaction of 1-phenylpropane with limited chlorine in the presence of light is **1-chloro-1-phenylpropane**.