
TY  - JOUR
A1  - Howell, JR 
A1  - Rasmussen, M 
T1  - Heterocyclic Ambident Nucleophiles. V. Alkylation of Benzimidazoles
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1993
VL  - 46
IS  - 8
SP  - 1177
EP  - 1191
KW  - 
UR  - https://doi.org/10.1071/CH9931177 
N2  - 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 N1 for 5-nitro and N3 for 5-methoxy systems. With 4-substituted benzimidazole anions, alkylation gave more divergent results with the N1 to N3 regioselectivity varying between 100:0 and 29:71. These alkylation patterns are interpreted as deriving from an interplay of electrostatic, thermodynamic, 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. 
ER  -

