CuO-NPs/TFA: a New Catalytic System to Synthesize a Novel Series of Pyrazole Imines with High Antioxidant Properties

We report here the synthesis of a novel series of pyrazole analogs involving the condensation reaction between 5-amino-1H-pyrazole-4-carbonitrile derivatives and carbonyl compounds. The reactions proceeded in acidic media, and were catalyzed by copper oxide nanoparticles (CuO- NPs) which were synthesized under green condition. The tea leaves extract served as green reducing agent for the conversion of copper nitrate to CuO-NPs. The developed methodology afforded the desired products up to 90% yields in 6 h. The newly synthesized compounds were tested for antioxidant properties. Out of 15 newly developed pyrazole compounds, 11 showed better antioxidant activity than the standard antioxidant drug Trolox.

Automated summary

A novel series of pyrazole analogs was synthesized through condensation reaction between 5-amino-1H-pyrazole-4-carbonitrile derivatives and carbonyl compounds in acidic media, catalyzed by CuO-NPs synthesized under green condition using tea leaves extract as reducing agent. The newly developed pyrazole compounds showed better antioxidant activity than Trolox, with 11 out of 15 compounds exhibiting improved properties.