COMEDK2023Morning ShiftChemistryAminesActual
Rank the following compounds in order of increasing basicity.
Options
- A4 < 2 < 1 < 3
- B4 < 3 < 1 < 2
- C4 < 1 < 3 < 2
- D2 < 1 < 3 < 4
Correct answer
B. 4 < 3 < 1 < 2
Step-by-step solution
Compound 1: Aniline ( C₆H₅NH₂ ) - lone pair on N delocalised into ring via resonance moderate basicity. Compound 2: Benzylamine ( C₆H₅CH₂NH₂ ) - NH₂ not directly attached to ring, no resonance with ring most basic among these. Compound 3: 2-Nitroaniline - -NO₂ at ortho position withdraws electrons by both inductive and resonance effects, plus steric hindrance prevents coplanarity reducing basicity further less basic than aniline. Compound 4: Benzamide ( C₆H₅CONH₂ ) - lone pair on N delocalised into C=O (amide reson