Heterocyclic ambident nucleophiles. V. Alkylation of benzimidazoles was written by Howell, John R.;Rasmussen, Malcolm. And the article was included in Australian Journal of Chemistry in 1993.Reference of 4887-83-6 This article mentions the following:
Alkylation of 5-substituted benzimidazole anions with a variety of primary alkyl halides in both protic and aprotic solvents showed only small regioselectivity, with a slight preference for reaction at N(1) for 5-nitro and N(3) for 5-methoxy systems. With 4-substituted benzimidazole anions, alkylation gave more divergent results, with the N(1) to N(3) regioselectivity varying between 100:0 and 29:71. These alkylation patterns are interpreted as deriving from an interplay of electrostatic, thermodn., steric and associative control factors within the variable SN2 transition state structures involved. In the 4-substituted series, proximity effects, both electrostatic field and steric non-bonded, are clearly dominant. In the experiment, the researchers used many compounds, for example, 7-Methyl-1H-benzo[d]imidazole (cas: 4887-83-6Reference of 4887-83-6).
7-Methyl-1H-benzo[d]imidazole (cas: 4887-83-6) belongs to imidazole derivatives. Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. This ring system is present in important biological building blocks, such as histidine and the related hormone histamine.Reference of 4887-83-6
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem