The correct IUPAC name of the compound (CH3)2CHCH(Br)CH2CH2Cl, is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 3-bromo-1-chloro-4-methylpentane
To name a haloalkane by the IUPAC system:
Choose the longest carbon chain; groups not in it are substituents.
Number the chain so that the substituents together get the lowest set of locants (compare at the first point of difference). Halogens and alkyl groups are treated alike here.
Write the prefixes in alphabetical order: bromo, chloro, methyl.
The compound written out is:
\( \displaystyle \ce{CH3-CH(CH3)-CH(Br)-CH2-CH2-Cl} \)
The longest chain has five carbons (pentane); one \( \ce{CH3} \) of the isopropyl end is a methyl branch.
Numbering from the Cl end: Cl on C-1, Br on C-3, \( \ce{CH3} \) on C-4, locants {1, 3, 4}.
Numbering from the other end: \( \ce{CH3} \) on C-2, Br on C-3, Cl on C-5, locants {2, 3, 5}.
At the first point of difference 1 is lower than 2, so the chain is numbered from the Cl end. The name is 3-bromo-1-chloro-4-methylpentane.