$R - NH _{2}+ Na _{2} CO _{3}+ NaBr + H _{2} O$

$R - CO - NH _{2}+\overline{ O }H \rightarrow R - CO -\overline{ N }H \stackrel{ Br _{2}}{\longrightarrow}$

$R - CO - NH - Br \stackrel{ OH ^{-}}{\longrightarrow} R - CO -\overline{ N }- Br$

$\stackrel{\text { migration of } \overline{ R }}{\longrightarrow} R - NCO \stackrel{2 \overline{O}H}{\longrightarrow} RNH _{2}+ CO _{3}^{2-}$

In this reaction of alkyl as well as aryl group can migrate to electron deficient nitrogen atom.