Unexpected synthesis of benzimidazole from Schiffbase mediated by lanthanide chloride and citotoxic activities

Schiffbases and benzimidazoles compounds exhibit an extensive range of therapeutic applications, such as anticancer agents. The present study shows the synthesis of the 2-(4-methoxyphenyl)1H-benzimidazole hydrochloride (BenzHCl) from N,N'-bis-(4-methoxybenzylidene)-benzene-1,2-diamine (Anisalophen) mediated by chloride lanthanide (Gd3+, Tb3+, or Eu3+). The mechanism of the reaction is proposed from different synthetic strategies. BenzHCl crystallizes in the monoclinic system, space group P2(1) and shows the iminic nitrogen atom protonated, which is stabilized by the chlorine ion. BenzHCl and Anisalophen were characterized, and their thermal stabilities were analyzed by TG/DTA techniques. Anisalophen and BenzHCl showed higher cytotoxic activity against human breast cancer cells (MCF-7 and MDA-MB-231) when compared to human fibroblast cells. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Schiffbases and benzimidazoles have a wide range of therapeutic applications, including as anticancer agents. The synthesis of BenzHCl mediated by chloride lanthanide and its cytotoxic activity against human breast cancer cells indicate potential anticancer properties.