Question

The correct order of the decreasing order of basic strengths of the following compounds is:

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

Answer 1

The correct option is B II> III > I

Of the given compounds, look at the kind of atoms/functional groups immediately flanking the nitrogen atom. We know that the nitrogen in each of the compounds contains two lone pairs each. Also, the carbonyl group is strongly electron withdrawing. The greater the number of (negative charge) stabilizing factors immediately around the charge bearing nitrogen atom, the weaker the base.
Hence, II > III > I