The correct order of basicities of the following compounds is:

(1) > (3) > (2) > (4).(1) More basic due to the presence of two LP e¯ on each N.(2) EtNH2. Due to + I effect of (Et) group, but +I effect of two Me groups is greater than +I effect of (Et) group. Hence, (3)is more basic than (2).(3) (CH3)2NH. Due to (+I) effect of two Me groups.(4) (Amides are resonance stabilised; so they are the weakest bases. Amides behave as amphoteric.)