Question

How do we rationalize the `""^1H` `"NMR spectrum"` of `C_6H_5CH_2CH_2NH_2`?

Answer 1

We look at the types of protons in the molecule....

Explanation:

...i.e. we look at the protons that are chemically equivalent....

Using the given principles, I claim that for `C_6H_5CH_2CH_2NH_2`, there should be 6 absorptions observed in a `1:2:2:2:2:2` ratio, the which corresponding to 3 sets of aryl protons, 2 sets of methylene protons, and 1 set of amino protons, and this is the reason why we always integrate the `""^1H` `"NMR spectrum"` as a necessary preliminary to aid assignment.

It should be easy to differentiate the aryl protons from the aliphatic ones.. The amino protons, i.e. `NH_2`...have 2 neighbours (the `CH_2` unit), but I doubt that you will see coupling....i.e. they should appear as a singlet.