Question

Which of the following orders is true regarding the basic nature of $-N{H}_2$ group?

• A. $o$ -Toluidine $>$ Aniline $>o$ -Nitroaniline
• B. $o$ -Toluidine $<$ Aniline $>o$ -Nitroaniline
• C. $o$ -Toluidine $<$ Aniline $<o$ -Nitroaniline
• D. $o$ -Toluidine $>$ Aniline $<o$ -Nitroaniline

Answer 1

Answer: (B)

Ortho-substituted anilines are weaker bases than anilines regardless of the nature of the substituent whether electron releasing or electron withdrawing. This is called ortho effect and is probably due to a combination of steric and electronic factors.