Identify the allyl chloride from the following:

The correct answer is Option (3) → 

An allyl chloride is a compound in which chlorine is attached to an allylic carbon.

Allylic carbon = carbon adjacent to a C=C double bond.

General structure:

$CH_2=CH-CH_2Cl$

The Cl must be attached to the carbon next to the double bond, not directly on the double bond and not on aromatic ring.

Option-wise Explanation

Option 1

Cl is attached to side chain of benzene ring.

This is a benzyl chloride, not allyl chloride.

Option 2

Chlorine is attached to saturated ring carbon.

No adjacent double bond.

Not allylic.

Option 3

Chlorine is attached to carbon next to the double bond.

This is an allylic position.

Hence, allyl chloride.

Option 4

Chlorine is directly attached to carbon of double bond.

This is vinylic chloride.

Not allylic.