Question

Arrange the following in the decreasing order of basic character.
I. p-toluidine
II. N, N-dimethyl-p-toluidine
III. p-nitroaniline
IV. Aniline

• A. II > III > I > IV
• B. I > II > III > IV
• C. II > I > IV > III
• D. IV > III > I > II

Answer 1

The correct option is C II > I > IV > III

1. The $+I$ effect of 2 methyl group of N and hyper conjugation of methyl group at para position makes the $N,N-dimethyl-p-toluidine$ more basic.

2. para toluidine shows the + I and hyperconjugation of one methyl group at position makes it less basic than N,N-dimethyl-p-toluidine.

3. paranitroaniline shows -R effect of $N{O}_2$ group at para position, it is the least basic compound.

Hence, the order is $II>I>IV>III$

Option C is correct.