Fundamentals of Organic ChemistryChemistryAmines
Which of the following statements is correct regarding the basicity of the given primary amines? (i) (ii)
Options
- A(i) < (ii) because of the difference in the nature of the -carbon.
- B(ii) > (i) because (ii) is an aliphatic amine.
- C(i) > (ii) because (i) is an aromatic amine.
- DBoth are equally basic because both are 1^ amines.
Correct answer
A. (i) < (ii) because of the difference in the nature of the -carbon.
Step-by-step solution
The basicity of an amine depends on the availability of the lone pair of electrons on the nitrogen atom for protonation. In both compounds, the - NH₂ group is attached to an sp^3 hybridized carbon (the -carbon). In benzylamine (i) , the -carbon is attached to a phenyl ring. The carbon atom of the phenyl ring directly attached to the -carbon (the -carbon) is sp^2 hybridized. Since sp^2 hybridized carbons are more electronegative than sp^3 hybridized carbons, the phenyl group exerts an electron-withdrawing inductive