4,6-Dimethoxy-2-substituted-benzimidazoles undergo formylation, acylation, nitration and bromination at C7. The 7-carbaldehydes can be reduced to the corresponding hydroxymethyl compounds. Benzimidazole-2-carbaldehydes can be prepared by oxidation of 2-methyl- and 2-styryl-benzimidazoles. N-Methylation and N-allylation have also been investigated and lead to isomeric mixtures of 4,6- and 5,7-dimethoxybenzimidazoles. In general the nucleophilic capacity of the activated benzimidazoles is weaker than that of the related activated indoles, but still provides synthetic routes to a range of new heterocyclic structures.

中文翻译：

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4,6-二甲氧基活化的苯并咪唑的反应性

4,6-二甲氧基-2-取代的苯并咪唑在C7进行甲酰化，酰化，硝化和溴化。7-甲醛可以还原为相应的羟甲基化合物。苯并咪唑-2-甲醛可以通过氧化2-甲基-和2-苯乙烯基-苯并咪唑来制备。还已经研究了N-甲基化和N-烯丙基化，并导致了4,6-和5,7-二甲氧基苯并咪唑的异构体混合物。通常，活化的苯并咪唑的亲核能力比相关的活化的吲哚的亲核能力弱，但是仍然提供了合成一系列新杂环结构的途径。