The Co ²⁺ Complex of [7‐Hydroxy‐4‐methyl‐8‐coumarinyl]glycine as a Nanocatalyst for the Synthesis and Biological Evaluation of New Mannich Bases of Benzimidazoles and Benzothiazoles

Abstract

Abstract In this paper, a series of novel Mannich bases of benzimidazoles and benzothiazoles were synthesized via a one‐pot two steps reaction of 1,2‐phenylenediamines or 2‐aminothiophenols with several in situ synthesized Mannich bases of aldehydes in the presence of nanostructured Co 2+ complex of [7‐hydroxy‐4‐methyl‐8‐coumarinyl]glycine ([Co(MCG)(H 2 O) 3 ] as a reusable and bioactive catalyst. To the best of our knowledge, it is the first report on the application of nanostructured coumarin‐based metal complexes [M(MCG)(H 2 O) 3 ] for the synthesis of organic compounds. The nanostructured coumarin‐based cobalt complex as a catalyst could be reused up to six times without a decrease in its catalytic activity. The cytotoxic activities of synthesized benzimidazoles were investigated against the colon cancer cell line (HT‐29) and fibroblasts cell lines (HFF) as a non‐cancerous cell line, at 24 and 72 hours after incubation using 3‐(4, 5‐Dimethylthiazol‐2‐yl)‐2, 5‐diphenyl tetrazolium (MTT) assay.