Facile DES-mediated synthesis and antioxidant potency of benzimidazoquinazolinone motifs

One-pot multicomponent synthesis of benzimidazoquinazolinone scaffolds was achieved by reaction between 2-aminobenzimidazole, aldehyde, and 1,3-cyclohexadione in choline chloride:glycerol as deep eutectic solvent (DES). The developed methodology offers mild and faster reaction conditions with excellent product yield. The synthesized compounds were screened for their antioxidant potency using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and metal chelating assay. Most of the compounds were found to exhibit good to comparable antioxidant activity with respect to standards. Use of this inexpensive and biodegradable solvent makes this methodology a greener approach compared with other methods reported in literature. Graphical Abstract Greener, one-pot multicomponent synthesis of benzimidazoquinazolinone scaffolds using DES (ChCl:glycerol) as efficient, recyclable, and biodegradable solvent has been achieved. The synthesized compounds show good to comparable antioxidant activity compared with standards.