Question

What is the correct IUPAC name of the given compound?

• A. 1-Bromo-2-ethylpropane
• B. 1-Bromo-2-ethyl-2-methyl ethane
• C. 1-Bromo-2-methylbutane
• D. 2-Methyl-1-bromobutane

Hint:

In IUPAC naming, first choose the longest chain, then number it to give substituents the lowest possible locants.

Answer 1

The Correct Option is C

Concept:
For IUPAC naming of haloalkanes, we follow these steps: \[ \text{Choose the longest carbon chain} \] \[ \text{Number the chain to give lowest locants to substituents} \] \[ \text{Name substituents in alphabetical order} \]

Step 1: Identify the longest chain.
From the given compound, the longest continuous carbon chain contains four carbon atoms. So the parent hydrocarbon is: \[ \text{butane} \]

Step 2: Identify substituents.
The substituents are: \[ \text{bromo group} \] and \[ \text{methyl group} \]

Step 3: Number the chain.
Number the chain from the end nearer to the bromo group. This gives: \[ \text{bromo at carbon 1} \] and: \[ \text{methyl at carbon 2} \]

Step 4: Write the IUPAC name.
Parent chain: \[ \text{butane} \] Substituents: \[ 1\text{-bromo},\quad 2\text{-methyl} \] So the name is: \[ \text{1-Bromo-2-methylbutane} \]

Step 5: Check the options.
Option (A) uses an incorrect parent chain.
Option (B) is not a proper IUPAC name.
Option (C) is correct.
Option (D) has the same substituents, but option (C) matches the standard naming style used in the paper. Hence, the correct answer is: \[ \boxed{(C)\ \text{1-Bromo-2-methylbutane}} \]