Question

The IUPAC name for

• A. 1-chloro-2-nitro-4-methylbenzene
• B. 1-chloro-4-methyl-2-nitrobenzene
• C. 2-chloro-1-nitro-5-methylbenzene
• D. m-nitro-p-chlorotoluene

Hint:

When naming disubstituted benzene rings, use the prefixes ortho- (o-), meta- (m-), and para- (p-) to indicate the relative positions of the substituents. However, for IUPAC naming, numerical locants are preferred.

Answer 1

The Correct Option is B

Step 1: Identify the substituents and their positions on the benzene ring. The benzene ring has three substituents:
1. Chlorine (Cl) at position 1.
2. Nitro group \((NO_{2})\) at position 2.
3. Methyl group \((CH_{3})\) at position 4. 
Step 2: Assign the IUPAC name based on the substituent positions. The correct IUPAC name follows the numbering that gives the lowest possible locants to the substituents. 
The name is: 1-chloro-4-methyl-2-nitrobenzene.