Nitrogen containing heterocyclic compounds such as oxindoles especially isatins and their derivatives have excellent biological properties such as anti-inflammatory, antimicrobial, anticancer activity. In addition, this is first time ever we would like to report the antioxidant properties of the said class of compounds. To determine such an important bioactivity a number of halogenated oxindoles 1-3, their diaza-biphenyl derivatives (4-6), ring extended biphenyl (7) and bis-amide (8) were synthesized by classical heating method. The antioxidant activity of all the synthesized compounds was screened by DPPH method with respect to ascorbic acid. In our present investigation some of the synthesized compounds (1, 2, 3, 5 and 6) were found to be active.