The common name and IUPAC name of the following compound, respectively, are
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → o-Toluidine and 2-Methylaniline
The structure shows a benzene ring with two substituents:
• An –NH₂ (amino group)
• A –CH₃ (methyl group)
The –NH₂ group is taken as the principal functional group, so the parent compound is aniline (or benzenamine in strict IUPAC terminology).
Position of substituents
The methyl group is adjacent to the amino group on the benzene ring. This arrangement corresponds to the ortho position (1,2-position). Thus the compound is ortho-substituted.
Common name
When a methyl group is attached to aniline in the ortho position, the compound is called: o-Toluidine
IUPAC name
In IUPAC nomenclature:
• The parent compound is aniline (benzenamine)
• The methyl group is at position 2
Thus the IUPAC name becomes: 2-Methylaniline
Option 2: o-Toluidine and 2-Methylaniline
The compound contains a methyl group in the ortho position relative to the amino group, giving the common name o-toluidine and IUPAC name 2-methylaniline. Hence this option is correct.