Synthesis and antioxidant properties of novel pyrimidine-containing heterocycles

4-(Benzo[d][1,3]dioxol-5-yl)-2-hydrazinyl-6-oxo-1,6-dihydropyrimidine-5-carbonitrile was utilised to construct fused heterocyclic systems, namely triazolopyrimidines, as well as non-fused heterocyclic systems such as pyrazole and dioxopyrazolidine derivatives. The antioxidant activity of the new compounds was evaluated. Most of the synthesised compounds have potent antioxidant activity.