isocyanide dichloride
Isocyanide dichlorides are organic compounds containing the RN=CCl2 functional group. Classically they are obtained by chlorination of isocyanides. Phenylcarbylamine chloride is a well-characterized example.
Preparation and reactions
Chlorination of organic isothiocyanates is also well established:{{cite book|title= Cyanates and Their Thio Derivatives: Part 2, Volume 2 |editor=Saul Patai|year=1977|chapter= Syntheses and Preparative Applications of Thiocyanates |author=R. G. Guy|doi=10.1002/9780470771532.ch2|series=PATAI'S Chemistry of Functional Groups|page= 619-818|isbn=9780470771532 }}
:RN=C=S + 2{{nbsp}}Cl2 → RN=CCl2 + SCl2
Alkylisocyanates are chlorinated by phosphorus pentachloride:
:RN=C=O + PCl5 → RN=CCl2 + POCl3
Cyanogen chloride also chlorinates to give the isocyanide dichloride:
:ClCN + Cl2 → ClN=CCl2
Reactions
Isocyanide dichlorides participate in Friedel-Crafts-like reactions, leading, after hydrolysis, to benzamides:
:RN=CCl2 + ArH → RN=C(Cl)Ar + HCl
:RN=C(Cl)Ar + H2O → R(H)NC(O)Ar + HCl