Tricyclic Heteroaromatic Ring Systems IV. Synthesis and Reactions of 4H-Pyrazolobenzimidazole
The 4H-Pyrazolobenzimidazole ring system was prepared by an intramolecular Ullmann arylation of 4-substituted 1-(o-aminophenyl)pyrazole while other derivatives were obtained by functional group modifications.Some electrophilic substitutions (nitration, bromination) and alkylations were also carried out. - Keywords: Alkylation; Bromination; Nitration; Ullmann arylation