So basically it's a Sandmeyer reaction, but I've got a scheme which dosen't use a copper catalysit.
The simplified procedure looks like this: p-toluedine is dissolved in HCl then a NaNO3 solution is added. Then I add carbamide, then KI solution(everything is done in a low temperature) Then I heat the mixture and add NaOH.
So I would like to know what is the function of carbamide and NaOH.