In this case, the basicity of the compounds is influenced by the electron-withdrawing or electron-donating groups attached to the benzene ring. The amino group (-NH ) is an electron-donating group, which increases the basicity of the compound.
In contrast, electron-withdrawing groups like -NO or -Cl will decrease the basicity of the compound.
- Compound 1: The amino group (-NH ) is electron-donating, increasing the basicity.
- Compound 2: The -Cl group is electron-withdrawing, making the compound less basic.
- Compound 3: The -NO group is strongly electron-withdrawing, further decreasing basicity compared to compound 2.
- Compound 4: The amino group (-NH ) is present again, but the -NO group is also attached, significantly reducing its basicity.
Thus, the order of increasing basicity is: 4<3<1<2.