53703-88-1Relevant articles and documents
"All-water" chemistry of tandem N-alkylation-reduction- condensation for synthesis of N-arylmethyl-2-substituted benzimidazoles
Kommi, Damodara N.,Kumar, Dinesh,Bansal, Rohit,Chebolu, Rajesh,Chakraborti, Asit K.
, p. 3329 - 3335 (2013/01/16)
A water-assisted tandem N-alkylation-reduction-condensation process has been devised as a new synthetic route for the one-pot synthesis of N-arylmethyl-2-substituted benzimidazoles. Water plays the crucial and indispensable role through hydrogen bond mediated 'electrophile-nucleophile dual activation' in promoting selective N-monobenzylation of o-nitroanilines as an alternative to the transition metal-based chemistry for C-N bond formation (amination) and forms the basis of disposing the substituents on the benzimidazole moiety in regiodefined manner. Water also exerts a beneficial effect in the condensation of N-monobenzylated o-phenylenediamines with aldehydes. The water-assisted C-N bond formation chemistry led to metal/base-free synthesis of N-monobenzylated o-nitroanilines and N-monobenzylated o-phenylenediamines. The indispensable/advantageous role of water in the various stage of the N-alkylation-reduction-condensation process exemplifies an 'all-water' chemistry for the synthesis of N-arylmethyl-2- substituted benzimidazoles.
