Benzazoles: I. Regioselective arylsulfonylation of benzimidazol-2-amine

Benzimidazol-2-amine reacted with arenesulfonyl chlorides in the presence of triethylamine in regioselective fashion at the endocyclic nitrogen atom, the exocyclic amino group remaining intact. The yields of 1-arylsulfonylbenzimidazol-2-amines depend on the electronic properties of substituents in the benzene ring of arenesulfonyl chlorides. DOI: 10.1134/S1070428013010181