Arrange the following compounds in order of increasing basicity (least to most)in aqueous solution:
A)IV

Question

Arrange the following compounds in order of increasing basicity (least to most)in aqueous solution: 
A)IV < II < I < III 
B)III < II < IV < I 
C)II < I < III < IV 
D)II < III < I < IV 
E)Cannot be determined from information given

Quizplus · Accepted Answer

Basicity is related to the availability of lone pair of electrons on the nitrogen atom. In compound I, the nitrogen atom is participating in resonance with the adjacent carbonyl group, which reduces the availability of lone pair of electrons, making it the least basic. In compound IV, the nitrogen atom has two electron-withdrawing groups, i.e. the carbonyl group and the nitro group, making it the most basic compound. Compound II has one electron-withdrawing group, i.e. the carbonyl group, making it more basic than compound I but less basic than compound III. Compound III has no electron-withdrawing groups and contains a secondary amine, which is more basic than primary amine (compound II). Therefore, the correct order of increasing basicity is II < I < III < IV.

Arrange the Following Compounds in Order of Increasing Basicity (Least