see when  the ring contains electron releasing group at the ortho n para positions

this reduces the resonance of  with the ring

and it  should inc. the basicity (H BOND IS STRONGER , i hope i m right )

but this would happen with para positionn only

in ortho position   go out of plane (steric reason)

so resonance is alone from ( SO THIS TIME BOND ISWEAKER )

I THINK THIS SHOULD BE THE POSSIBLY THE REASON

but i'm not sure !

 in ortho methyl aniline, initially there is no steric repulsion. But in the conjugate acid, there is repulsion between the extra proton and the CH3 group at ortho position.............so less basic

 what is not clear?    

initially in the ortho isomer ther was no steric repulsion..........but once protonated, there is repulsion between the extra proton and the ortho CH3(as there is more crowding now) 

so the conjugate acid is not so stable....hence ortho methyl aniline is reluctant to get protonated  

hence it is less basic 

Kb of Toulidene(no.2 ) is 2.6 X 10^(-10)

Kb of Aniline is 4.2 X 10^(-10)

Implies Aniline is more basic.. Morrison and Boyd, people..

 mind giving the page no. of morrison from where you got those?    

i think it should b da 1st one coz of ortho effect due to ortho effect aniline is more basic than ortho methyl benzene

ie when dere is a group present in da ortho position of aniline den it due ortho effect it will be less basic dan aniline

ortho effect is applied to benzoic acid.

inductive effect do not depends on steric factor ther4    CH3 will hv its +I effect. anddddddddddddd

somewhat hyperconjugation , both of these effects increses electron density on N and ther4  ease in electron donation increses and hence basic strenght of latter is mor than former................