Chlorination of organic isothiocyanates is also well established: 
:RN=C=S  +  2Cl  →  RN=CCl  +  SCl
Alkylisocyanates are chlorinated by phosphorus pentachloride:
:RN=C=O  +  PCl  →  RN=CCl  +  POCl
Cyanogen chloride also chlorinates to give the isocyanide dichloride:
:ClCN  +  Cl  →  ClN=CCl