Acetamide reacts with ${\mathrm{Br}}_2/\mathrm{NaOH}$ to give

${\mathrm{RCONH}}_2\stackrel{{\mathrm{OBr}}^{-}}{⟶}{\mathrm{RNH}}_2+{\mathrm{CO}}_3^{2-}$.

The reaction occurs through intermediate formation of alkyl isocyanate which on hydrolysis gives methylamine and sodium carbonate.