Synthesis and antioxidant activities of some new triheterocyclic compounds containing benzimidazole, thiophene, and 1,2,4-triazole rings.

Various triheterocyclic compounds containing benzimidazole, thiophene, and 1,2,4-triazole rings (3-6) were synthesized and screened for their antioxidant activities. The structures of the synthesized compounds (2-6) were judged by (1)H NMR, (13)C NMR, elemental analysis, and LC-MS spectral data. Antioxidant activities of the synthesized compounds (2-6) were determined with CUPric Reducing Antioxidant Capacity (CUPRAC), ABTS (2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)/persulfate, and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays. Most of the compounds showed a significant antioxidant activity and especially, compound 5c showed very good SC50 value for DPPH method and compound 5h exhibited very high scavenging activity to ABTS method.