A range of 2-substituted-4,6-dimethoxy activated benzimidazoles and 2,2'-bisbenzimidazoles have been synthesized from 2-aminoanilide derivatives under acidic conditions. The starting materials were prepared either by acylation from 3,5-dimethoxyaniline followed by nitration, or by acylation from 3,5-dimethoxy-2-nitroaniline. The 2-nitroanilides were then reduced by palladium catalyzed reaction with hydrazine and subsequent acid catalyzed cyclization giving the corresponding 4,6-dimethoxybenzimidazoles and 4,6-dimethoxy-2,2'-bisbenzimidazoles. In addition, 2-phenyl-4,5,6-trimethoxybenzimidazole has been synthesized using a similar procedure.


中文翻译：

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二甲氧基活化的苯并咪唑和双苯并咪唑的合成

由2-氨基苯胺衍生物在酸性条件下合成了一系列2-取代的4,6-二甲氧基活化的苯并咪唑和2,2'-双苯并咪唑。通过从3，5-二甲氧基苯胺酰化然后硝化，或通过从3，5-二甲氧基-2-硝基苯胺酰化来制备原料。然后通过与肼的钯催化反应和随后的酸催化环化反应还原2-硝基苯胺，得到相应的4，6-二甲氧基苯并咪唑和4，6-二甲氧基-2，2′-双苯并咪唑。另外，已经使用类似的方法合成了2-苯基-4,5,6-三甲氧基苯并咪唑。