Selective phenol alkylation for an improved synthesis of 2-arylbenzimidazole H4 receptor ligands

Abstract Alkylation of a phenol OH in the presence of a free benzimidazole NH was investigated and found to be highly dependent on the substitution of the benzimidazole and phenol rings. The modification of our original synthesis of 2-arylbenzimidazole H 4 receptor ligands has resulted in improved yields and ease of isolation of final products.