COMEDK2024Morning ShiftChemistryAminesActual
Which one of the following shows the correct increasing order of basic nature of the given compounds? A: Phenylmethanamine B: N-Ethylethanamine C:N, N-Dimethylaniline D : N, N-Dimethylmethanamine
Options
- AA < D < B < C
- BC < A < D < B
- CB < C < A < D
- DD < B < A < C
Correct answer
B. C < A < D < B
Step-by-step solution
The basicity of amines depends on the availability of the lone pair on the nitrogen atom. Electron-donating groups increase basicity, while electron-withdrawing groups or resonance delocalization decrease it. Compound A is Phenylmethanamine ( C₆H₅CH₂NH₂ ), a primary amine where the lone pair is not delocalized into the ring, but the phenyl group exerts a weak inductive effect. It is more basic than aromatic amines but less basic than aliphatic amines. Compound B is N-Ethylethanamine ( (C₂H₅)₂NH ), a secondary aliph