Novel Pyrazolo[1,5-a]Pyrimidines and Pyrazolo[5,1-c][1,2,4]Triazines Incorporating Indole Moiety as a New Class of Antioxidant Agents

This effort focuses on the construction of novel pyrazolo[1,5-a]pyrimidines bearing indole nucleus via the reaction of 3-(1H-indol-3-yl)-1H-pyrazol-5-amine (3) with the appropriate reagents or through solvent free condensations with active methylene components and triethyl orthoformate. The utility of (3) for the preparation of pyrazolo[5,1-c][1, 2, 4]triazines was also explored via coupling of diazonium salt of (3) with active methylene compounds. Antioxidant activity screening of the synthetic targets showed that compounds (13), (14), (16), and (17) exhibited a promising activity.