STABLE CARBENE ADDUCTS OF CHLORINE [1]

The carbene adducts 3a-c (R-1 = Me, Et, iso-Pr; R-2 = Me) are formed f rom the 2,3-dihydroimidazol-2-ylidenes 1a-c and 1,2-dichloroethane as air-sensitive solids in good yields. The compounds exhibit a reactive Cl-Cl bond. Benzene is chlorinated by 3a,b to give chlorobenzene and t he imidazolium salts 10a,b under mild conditions. 3c acts as a chlorid e donor to give with AlCl3 and SO2 the 2-chloroimidazorium salts 12c a nd 13c (X = AlC(4)l,, SO2Cl). On hydrolysis, the less reactive hydrate salt I-le is formed from 3c. The X-ray structures of 10a and 14c are reported.