JEE Main 2024 · 30 January · evening · Single correct · +4 / −1
IUPAC name of following compound is :
CH₃, -, CH, -, CH₂, -, CN; |; NH₂
- (a) 2-Aminobutanenitrile
- (b) 3-Aminopropanenitrile
- (c) 2-Aminopentanenitrile
- (d) 3-Aminobutanenitrile
Answer and solution
Answer (d) 3-Aminobutanenitrile
Solution
Chemistry ma’am · 4 steps
The carbon of -CN is part of the chain, so it becomes C1 and you count from there.
- Principal group. The nitrile -C≡N ranks above the amino group, so it gets the suffix "-nitrile" and -NH₂ becomes the prefix "amino".
- Count the chain. In the suffix "-nitrile", the C≡N carbon counts as a chain carbon. The chain is CH₃-CH-CH₂-C≡N, which has 4 carbons, so the parent is butanenitrile.
- Number from CN. The nitrile carbon is C1, CH₂ is C2, the CH carrying NH₂ is C3 and CH₃ is C4. So the amino group sits on C3.
- So. The name is 3-Aminobutanenitrile, option (d).
The idea to keep. With the suffix "-nitrile", the C≡N carbon is always C1 and is counted in the parent chain. Only "carbonitrile" names leave it out of the count.
Answer from the NTA final answer key. Solution by PrepWiser.