Question

The IUPAC name of(CH3)2CH - CH2 - CH2Br is

• A. 1-bromo-3-methylbutane
• B. 2-methyl-3-bromopropane
• C. 1-bromopentane
• D. 2-methyl-4-bromobutane

Answer 1

The Correct Option is A

To determine the IUPAC name of the given organic compound \((\text{CH}_3)_2\text{CH - CH}_2 - \text{CH}_2\text{Br}\), follow these steps:

1. Identify the Longest Carbon Chain: The longest chain in the given compound contains 4 carbon atoms. Hence, the base name is "butane."
2. Number the Carbon Chain: Number the carbon atoms in such a way that the substituents (in this case, halogen or alkyl groups) receive the lowest possible numbers. Bromine is on the first carbon when numbering starts from the end nearest the bromine atom.
   • Carbon 1: \(\text{Br}\)
   • Carbon 2: \(\text{CH}_3\) group (the methyl group from \((\text{CH}_3)_2\text{CH}\))
   • Carbon 3: Hydrogen
   • Carbon 4: Hydrogen (end of chain)
3. Identify Substituents and Their Positions: The carbon chain has a bromine substituent at position 1 and a methyl group at position 3.
4. Compose the IUPAC Name: Combining all these observations, the compound has one bromine atom and a methyl group. Therefore, the IUPAC name is "1-bromo-3-methylbutane."

Conclusion: The correct IUPAC name for \((\text{CH}_3)_2\text{CH - CH}_2 - \text{CH}_2\text{Br}\) is "1\text{-bromo-3-methylbutane}," which corresponds to option 1.