Benzimidazolium Salt Reaction

To explore new synthetic methods, we set out a careful investigation of the reaction of benzimidazolium salt with many nucleophilic agents, including the active aromatic compounds and heteratom nucleophilic agents, and found that the quaternary C=N is not so active; when benzimidazolium salt is reacted with big nitrogen nucleophilic agent?phthalimide, it does not give the expected addition product, instead, produces N-alkyl phthalimide through alkyl-transfermation from benzimidazolium salt to phthalimide. The mechanism of the reaction is discussed.5-nitro-2-alkyl-benzimidazoIe is a kind of special aromatic nitre-compound. There is no report of their reduction under alkaline conditions. By nitration of benzimidazoles, six 5-nitro-2-alkyl-benzimidazoles were prepared, the reduction of 5-nitro-2-alkyl-benzimidazole under either acidic or alkaline conditions was carefully carried out, and as a result, six 5-amino-2-alkyl-benzimidazoles were prepared by optimized method.To improve toluene nitration process, by cross experiment, the mono-nitration condition of toluene was optimized, and while several sulfate and surface-active-agent were used as catalysts the ratio of p-MNT to o-MNT was explored.