抄録
Reactions of 1-methyl- or 1, 2-dimethyl-3-methoxybenzimidazolium iodide (I or II) with various nucleophilic reagents (CN-, OH-, RO-, amines etc.) have been investigated. Most of these reagents reagents react with I to give the corresponding 2-substituted 1-methylbenzimidazole.The reaction of II with these reagents generally affords 1, 2-dimethylbenzimidazole (V) losing its methoxy group. Only with potassium cyanide, II undergoes substitution concurrently to give a mixture of 1, 2-dimethyl-6-benzimidazolecarbonitrile and V. The reaction mechanisms have been discussed as compared with those of Nalkoxypyridinium salt, and a possible zwitterion intermediate for the reaction of I is noted.
