Account for the following: (i) Primary amines (R−NH2) have higher boiling points than tertiary amines (R3N). (ii) Aniline does not undergo Friedel-Crafts reaction. (iii) (CH3)2NH is more basic than (CH3)3N in an aqueous solution.

(i) Due to intermolecular hydrogen bonding in primary amines (presence of more number of H-atoms )
(ii) Because aniline is basic in nature and reacts with AlCl3 to form salt. The positive charge on the N-atom, electrophile substitution in the benzene ring is deactivated. (refer to given image)
(iii) Due to steric hindrance and solvation factor in case of (CH3)3N, it is less basic than (CH3)2NH in aqueous solution.

Eduprobe

Question:

Account for the following:
(i) Primary amines (R−NH2) have higher boiling points than tertiary amines (R3N).
(ii) Aniline does not undergo Friedel-Crafts reaction.
(iii) (CH3)2NH is more basic than (CH3)3N in an aqueous solution.

Solution:

Question:

Account for the following:(i) Primary amines (R−NH2) have higher boiling points than tertiary amines (R3N).(ii) Aniline does not undergo Friedel-Crafts reaction.(iii) (CH3)2NH is more basic than (CH3)3N in an aqueous solution.

Solution:

Account for the following:
(i) Primary amines (R−NH2) have higher boiling points than tertiary amines (R3N).
(ii) Aniline does not undergo Friedel-Crafts reaction.
(iii) (CH3)2NH is more basic than (CH3)3N in an aqueous solution.