Write the IUPAC name of the following compound C_6H_5-O-(CH_2)_6-CH_3

The correct answer is Option (2) → 1-Phenoxyheptane

In the IUPAC system an ether is named as a hydrocarbon in which an H atom is replaced by an –OR or –OAr group, and the larger group is chosen as the parent hydrocarbon. In \( \ce{C6H5-O-(CH2)6-CH3} \) the heptyl chain (seven carbons) is the parent, heptane, and \( \ce{C6H5O} \)– is the phenoxy substituent on carbon 1. So the name is 1-phenoxyheptane (common name heptyl phenyl ether).

Why the other options are incorrect

• Option (1) 2-Methoxyheptane — Incorrect. This is \( \ce{CH3O-CH(CH3)-C5H11} \); it has a methoxy group on carbon 2 and no phenyl group.

• Option (3) 1-Benzoylheptane — Incorrect. A benzoyl group is \( \ce{C6H5CO} \)–; this name describes a ketone, not an ether.

• Option (4) Methyl benzyl ether — Incorrect. This is \( \ce{C6H5CH2-O-CH3} \), with only eight carbon atoms.

NCERT (2026-27 edition):
Nomenclature – “… According to IUPAC system of nomenclature, ethers are regarded as hydrocarbon derivatives in which a hydrogen atom is replaced by an –OR or –OAr group, where R and Ar represent alkyl and aryl groups, respectively. The larger (R) group is chosen as the parent hydrocarbon.”

Common and IUPAC Names of Some Ethers (rows of Table 7.2)