Isocyanide dichloride
# Isocyanide dichloride

Isocyanide dichlorides are organic compounds containing the $RN=CCl_2$ 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:

    RN=C=S + 2 $Cl_2$ → $RN=CCl_2$ + $SCl_2$

Alkylisocyanates are chlorinated by phosphorus pentachloride:

    RN=C=O + $PCl_5$ → $RN=CCl_2$ + $POCl_3$

Cyanogen chloride also chlorinates to give the isocyanide dichloride:

    ClCN + $Cl_2$ → $ClN=CCl_2$

## Reactions

Isocyanide dichlorides participate in Friedel-Crafts-like reactions, leading, after hydrolysis, to benzamides:

    $RN=CCl_2$ + ArH → RN=C(Cl)Ar + HCl
    RN=C(Cl)Ar + $H_2O$ → R(H)NC(O)Ar + HCl
