# order of basic strength

2 is the least basic as the lone pair is involved in aromatizing the ring 1 is the maximum basic as one of the lone pairs is used to aromatize the ring and the other lone pair is available but how do we distinguish between 3 and 4 the options are:

a.1>3>4>2

b.3>2>4>1

c.4>3>2>1

d.3>4>2>1

by the above discussion we can make out that the answer is a. but how to distinguish between option 3 and 4. how can we say that 3 is more basic than 4.

• All your answers are wrong, and that's particularly bad question. 3 and 4 are more basic than 2. – Mithoron Dec 18 '15 at 17:08
• As Mithoron points out this is a bad question. The basicities of 3 and 4 are close and they flip-flop depending upon whether we are discussing gas phase or solution basicity. In solution (you can google the pKas) the correct answer would be 3>4>1>2. You are correct that 2 is least basic because the lone pair is involved in aromaticity. 2 is more basic because the most available of the 2 lone pairs is in an sp2 orbital. Finally 3 and 4 are the most basic because their lone pairs are in an sp3 orbital. – ron Dec 18 '15 at 17:30

I think 4 should me more basic than 3 since $-CH_3$ has $+I$ effect due to which electron density on $N$ increases.
• How can you say 1 is most basic? both 3 and 4 too have localized lone pair and since in 1 Nitrogen is $sp^2$ hybridized its basic strength decreases with respect to 3 and 4. – Vaibhav Dec 18 '15 at 14:37