Synthesis and antioxidant activity of amido-linked benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrroles and pyrazoles

The amido-linked benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrroles and benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrazoles were prepared from the synthetic intermediates (E)-N-(benzoxazol-2-yl)cinnamamide/(E)-N-(benzothiazol-2-yl)cinnamamide/(E)-N-(1H-benzimidazol-2-yl)cinnamamides adopting simple and versatile synthetic methodologies. All the new compounds were tested for antioxidant activity. The compounds 5b, 8b and 14b displayed greater antioxidant activity when compared with the standard drug ascorbic acid. It was also observed that benzoxazolyl amido-linked derivatives displayed greater radical scavenging activity than the benzothiazolyl and benzimidazolyl amido-linked derivatives. The amido-linked benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrroles and benzoxazolyl/benzothiazolyl/benzimidazolyl-pyrazoles were prepared from the synthetic intermediates (E)-N-(benzoxazol-2-yl)cinnamamide/(E)-N-(benzothiazol-2-yl)cinnamamide/(E)-N-(1H-benzimidazol-2-yl)cinnamamides adopting simple and versatile synthetic methodologies. All the new compounds were tested for antioxidant activity. The compounds 5b, 8b and 14b displayed greater antioxidant activity when compared with the standard drug Ascorbic acid. It was also observed that benzoxazolyl amido-linked derivatives displayed greater radical scavenging activity than the benzothiazolyl and benzimidazolyl amido-linked derivatives.