A new and convenient protocol is presented for the synthesis of 1-arylbenzimidazol-2-ones
by a one-pot reaction of N-aryl-2-nitrosoanilines using solid carbon dioxide as a source of the key carbonyl
moiety. The metal-free process is carried out under mild conditions and is compatible
with a variety of substituents. The atom economy of the synthesis of the starting
nitrosoanilines, accomplished by substitution of hydrogen, makes the entire synthesis
of the target compounds environmentally friendly.
Key words
annulations - heterocycles - cyclizations - nitroso compounds - fused-ring systems
