text: Carbamoyl chlorides are prepared by the reaction of an amine with phosgene: 
  :2 RNH + COCl → RNCOCl + [RNH]Cl
  They also arise by the addition of hydrogen chloride to isocyanates:
  :RNCO + HCl → RNHCOCl
  In this way, carbamoyl chlorides can be prepared with N-H functionality.