Question

Which among the following is benzylic halide?

• A. Bromophenylmethane
• B. 4-Bromotoluene
• C. 1-Bromo-2-phenylethane
• D. Bromobenzene

Hint:

Benzylic carbon = carbon next to benzene ring (not on ring).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Halides are classified based on the nature of the carbon atom bonded to the halogen. A benzylic halide is a compound in which the halogen atom is bonded to an \(sp^3\) hybridized carbon atom that is directly attached to an aromatic ring (a benzene ring).
Step 2: Key Formula or Approach:
Draw or visualize the chemical structure for each option and check the hybridization of the carbon attached to the halogen and its proximity to the aromatic ring.
Step 3: Detailed Explanation:
Let's analyze the structures of the given options:
- (A) Bromophenylmethane (also known as benzyl bromide): The structure is \(\text{C}_6\text{H}_5\text{-CH}_2\text{-Br}\). Here, the Bromine is attached to a \(\text{CH}_2\) group (\(sp^3\) carbon) which is directly attached to the phenyl ring. This perfectly fits the definition of a benzylic halide.
- (B) 4-Bromotoluene: The structure has a bromine atom and a methyl group on opposite ends of a benzene ring (\(p\)-\(\text{Br-C}_6\text{H}_4\text{-CH}_3\)). The Br is attached directly to the \(sp^2\) carbon of the aromatic ring, making it an aryl halide.
- (C) 1-Bromo-2-phenylethane: The structure is \(\text{C}_6\text{H}_5\text{-CH}_2\text{-CH}_2\text{-Br}\). The Br is attached to an \(sp^3\) carbon, but this carbon is separated from the benzene ring by another carbon atom. It is a simple alkyl halide.
- (D) Bromobenzene: The structure is \(\text{C}_6\text{H}_5\text{-Br}\). The Br is attached directly to the aromatic ring, making it an aryl halide.
Step 4: Final Answer:
Bromophenylmethane is the benzylic halide.