Question

IUPAC name of isoprenaline is _______

• A. \( \text{4-[1-hydroxy-2-(isopropylamino)ethyl]benzene-1,2-diol} \)
• B. \( \text{4-[1-hydroxy-2-(isopropyl)ethyl]benzene-1,2-diol} \)
• C. \( \text{2-[1-hydroxy-2-(isopropylamino)ethyl]benzene-1,2-diol} \)
• D. \( \text{4-[1-hydroxy-2-(isobutylamino)ethyl]benzene-1,2-diol} \)

Hint:

When naming substituted benzenes, number the ring to give the lowest possible numbers to the substituents. Identify the principal functional groups and the longest carbon chain in the substituent.

Answer 1

The Correct Option is A

To determine the IUPAC name of isoprenaline, we need to analyze its structure. The benzene ring has two hydroxyl groups at positions 1 and 2, making it a benzene-1,2-diol (also known as catechol). The ethylamine substituent is attached to the benzene ring at position 4. The ethylamine group has a hydroxyl group at position 1 and an isopropylamino group at position 2. Therefore, the complete IUPAC name is 4-[1-hydroxy-2-(isopropylamino)ethyl]benzene-1,2-diol. Let's break down the name: - "benzene-1,2-diol" indicates the catechol ring. - The substituent on the benzene ring is at the 4th position. - The substituent is an ethyl group (-CH2-CH2-) with a hydroxyl group on the first carbon attached to the benzene ring (1-hydroxyethyl-) and an isopropylamino group (-NH-CH(CH3)2) on the second carbon (2-(isopropylamino)ethyl-). Combining these, we get 4-[1-hydroxy-2-(isopropylamino)ethyl]benzene-1,2-diol.